The URL can be used to link to this page

Home My WebLink About03741 - Technical Information Report � .. i' ' _ �' 3?�i c,�. r�.00 r�6� Vantage Point Apartments Technical Information Report � . �� ; �� - __ , _ : `� �� g � `� . � �°_ ��. „ � �� >�y� � �� " . -_ _ - _�-�"� � ' � : , � . �� = �: � � �_.._ _*.> � '. � _�> - ;- � March 14, 2016 � ASBUILT � Consulting Engineers � 3 7y/ k ff Technical Information Report March 14, 2016 Prepared for: Tonkin Architecture zo4 First Avenue South Seattle,WA 98io4 Prepared by: KPFF Consulting Engineers i6oi Fifth Avenue,Suite i600 Seattle,WA g8ioi (io6)6�z-58zz `SO G' CIS ' � 4�oF �'Sxr��o � FOR CITY � REVIEW ,0 32120 'po,�, ��'CI STE4� �� `Ss10NAL ��', Vantage Point Apartments Technical Information Report j k ff Table of Contents 1. Project Overview.............................................................................................................i �. Condition and Requirements Summary ............................................................................i Core Requirement No.i: Discharge at the Natural Location ......................................................i Core Requirement No. z: Off-Site Analysis ................................................................................z Core Requirement No.3: Flow Control.......................................................................................z Core Requirement No.4: Conveyance System...........................................................................z Core Requirement No. 5: Erosion and Sediment Control................................................z Core requirement No. 6: Maintenance and Operations.............................................z Core Requirement No.7: Water Quality.....................................................................................z 3. Off-Site Analysis .............................................................................................................z Task i: Study Area Definition and Maps.....................................................................................z Task z: Resource Review...................................................................................................••-......3 task3: Fieldlnspection...............................................................................................................3 Task 4: Drainage System Description and Problem Description .................................................3 Task 5: Mitigation of Existing or Potential Problems..................................................................4 4. Flow Control and Water Quality Facility and Design..........................................................5 ExistingSite Hydrolo9Y(Part A)..................................................................................................5 Developed Site Hydrology—Flow Control(Part B)......................................................................5 Developed Site Hydrology—Water Quality.................................................................................6 Performance Standards(Part C).................................................................................................6 5. Conveyance System Analysis and Design..........................................................................7 6. Special Reports and Studies.............................................................................................7 7. Other Permits .................................................................................................................7 I Vantage Point Apartments Technical Information Report �� k ff 8. Construdion Stormwater Pollution Prevention Plan Analysis and Design.............................8 Erosion Sediment Control Plan Analysis and Design(Part A)......................................................8 Stormwater Pollution Prevention and Spill Plan..........................................................................8 9. Bond Quantities,Facility Summaries,and Declarations of Covenant....................................8 BondQuantities Worksheet........................................................................................................8 Flow Control and Water Quality Facility Summary Sheet and Sketch..........................................8 Declaration of Covenant for Privately Maintained Flow Control and Water Quality Facilities......9 10. Operations and Maintenance Manual ...............................................................................g Appendices AppendixA—Maps and Worksheets • TIR worksheet • Site Location Map • Existing Conditions Map , • Drainage Basin Map • Soil Map • Offsite Analysis Map,Table,and confirmation record • Upstream Analysis ' Appendix B—Drainage Facility Documentation and Design ' • Detention Pond Documentation and Design ' • Rain Garden Documentation and Design • Backwater and Conveyance Analysis ', Appendix C—Special Reports and Studies j • Flood Zone Map � • Geotechnical Recommendations Appendix D—Construction Stormwater Pollution Prevention Plan • SWPPP Report and Calculations Appendix E—City of Renton Documents Vantage Point Apartments Technical Information Report j j� k ff • Bond Quantity Worksheet • Declarations of Covenant Appendix F—Operations and Maintenance Manual � i ;, Vantage Point Apartments Technical Information Report IV k ft � , � , , Vantage Point Apartments Technical Information Report V k ff 1 . Project Overview The project site is located at i79oi io5th Place Southeast, Renton,Washington g8o5S. The existing site topography is the result of historical legal mining operations as noted in the Geotechnical Report in Appendix C. The site is a relatively level grass covered bench,projecting approximately Zoo feet southward and westward from Southeast zo8th Street and io5th Place Southeast,respectively. Grades on the bench vary from 5 percent to z5 percent sloping toward the roadway. Outward of the bench is a steep slope at upwards of 5o percent down to the Vantage Glen Mobile Park on Southeast i8ist Street. The project proposes to shave down the bench,extending the top of steep slope to the west and south. The project does not propose clearing on the steep slope to remain. Stormwater sheets off of the existing site toward the City of Renton(City)-owned collection system in Southeast io8th Street and io5th Place Southeast. Runoff generated from the steep slope flows to the collection system at the toe of slope. The site area of disturbance is 3.99 acres. The proposed development includes an apartment building with two four story wings connected by a central common space. The north wing has one level of underground parking and the partially underground first floor of the south wing is mostly parking. There ' are two surface parking lots,one associated with the north building and the other with the south. Stormwater runoff from the proposed development will be collected in a series of catch basins and swales. Target pollution generating surfaces will be treated by on-site rain gardens to receive Enhanced I Basic Water Quality Treatment. The treated runoff is then routed to a Level Two detention pond to '� protect downstream fish bearing streams. The detention pond outlets to the City-owned storm drain in ' io5th Place Southeast. There is no change to the existing site discharge point. All runoff from property I within City right-of-way(ROW)that is within the limit of disturbance is considered bypass flow. The � detention facility is designed with a downstream point of compliance that accounts for this bypass flow. I . . . I 2. Condit�on and Requirements !� Summary The project is subject to all requirements in the City amendments to the zoog King County Surface Water Design Manual. The Core Requirements are listed below. No special requirements are applicable to the site. CORE REQUIREMENT N0. 1: DISCHARGE AT THE NATURAL LOCATION The project discharges to the two natural locations,the City-owned collection system in Southeast io8th Street and io5th Place Southeast,and the collection system at the toe of the steep slope in the Vantage Glen Mobile Park area. Vantage Point Apartments Technical Information Report '� k ff CORE REQUIREMENT N0. 2: OFF-SITE ANALYSIS An off-site analysis was performed on December g, zoi3. See Section 3 for details. CORE REQUIREMENT NO. 3: FLOW CONTROL The onsite Level z detention pond provides flow control to meet the Flow Control Duration Standard (Forested Conditions). The offsite basin does not exceed the threshold for detention, none is provided. See Section 4 for details. CORE REQUIREMENT N0. 4: CONVEYANCE SYSTEM All pipes and swales convey the z5-year event with 6 inches of available freeboard,with the exception of the trench drains. The shallow nature of these systems does not allow for the 6 inch freeboard. The pipes and swales convey the ioo-year event without overtopping. See Section 5 for details. CORE REQUIREMENT N0. 5: EROSION AND SEDIMENT CONTROL The project will comply with the National Pollution Discharge Elimination System(NPDES) permit. See Section 8 for details. CORE REQUIREMENT N0. 6: MAINTENANCE AND OPERATIONS The project will maintain the stormwater facilities. See Section io for details. CORE REQUIREMENT N0. 7: WATER QUALITY The project will provide enhanced basic water quality for all target pollution generating surfaces. See Section 4 for details. 3. Off-Site Analysis A Level i off-site analysis was performed on December 9, zoi3. City GIS data was used to assess the drainage network in the area and determine the flow path downstream. TASK 1: STUDY AREA DEFINITION AND MAPS The study area forthe site extends i mile downstream ofthe project. Discharge from the site enters the City conveyance system in io5`n Place Southeast and Southeast i8o`h Street and flows north to the 60- inch crossing at io5th Place Southeast and Southeast Carr Road. Runoffthen enters a tributary of Panther Creek. Runoff is carried in Panther Creek the remainder of the mile. There is one piped road crossing at Albot Road South,3/4 mile downstream of the site. See Appendix A for off-site analysis figure. Vantage Point Apartments Technical Information Report 2 k ff TASK 2: RESOURCE REVIEW Available flood plain maps,soil surveys,and sensitive area maps were reviewed to assess potential flooding or erosion associated with the development. City engineering stafFwas contacted for any known flooding problems in the area as well. The information available shows that there is no drainage problem that would be aggravated by the development. The proposed detention pond will reduce flows entering the City system compared to the currently grassed field. See Appendix A for correspondence with City staff and soils map,and Appendix C for Flood Insurance Rate Map. TASK 3: FIELD INSPECTION The field inspection was performed December g, zoi3. The weather was sunny and approximately 30 degrees Fahrenheit. There had been no rain for the past week. The field inspection started just upstream of the proposed connection to the system in io5th Place Southeast at CB 8057,see Figure 5 in Appendix A. The condition ofthe roadway curb and gutter suggests that the piped system is performing adequately. Surface conditions at structures did not indicate any overtopping or street flooding. There is some local ponding on io5`n PI SE that is likely caused by the extremely flat gradient of the gutter rather than storm drainage problems. The pavement along io5`n PI does not show any visible defects such as potholes or alligator cracking that would suggest saturated pavement subgrade andJor pavement pumping. Runofffrom the Fred Meyer site flowing in the ditch on the opposite side of io5`n PI SE joins the Vantage site and roadway runoff at MH 8i78. This manhole cover is offset from the street gutter line in the ivy covered slope fronting the Fred Meyer site. The next structure,CB A, is also offset from the gutter line. CB A is located in an elevated sidewalk that deviates a few feet East and a few feet vertically above the back of curb. Continuing downstream on io5`n PI SE, MH B is the next structure also located offset from the gutter line. The outer edge of the structure is placed against the sidewalk and the rim is set a few feet above the sidewalk elevation. The concrete structure would be fully visible if not for the _ dense ivy covering it and the adjacent rockery. From MH B,the system crosses io5tn PI SE to CB C and CB D. According to the City's GIS data,CB C should be located on the centerline of io5tn PI SE;however,it is not visible from the surface. CB C is likely paved over and buried. Continuing,CB D is located on private property in a landscaped area at the southwest corner of io5`n PI SE and SE Carr Rd. The system then turns west,still on private property,fronting the Kentucky Fried Chicken restaurant to CB E and CB F located in the restaurant parking lot. From CB F the system crosses SE Carr Rd to a CB G,a large vault junction structure in a wooded ravine north of SE Carr Rd. The vault lid is one to three feet above the surrounding area. The vault discharges east to the ravine with no evidence of scour at the outfall. The ravine bottom is a well defined drainage channel with 6 to i8 inch cobbles. There is no evidence of erosion in the channel and the side walls are relatively gentle with slopes ranging from approximately ' three to one to five to one. The channel bottom was dry at the time of the field inspection.See Appendix ' A, Figure 5 for the Offsite Analysis Map. ' TASK 4: DRAINAGE SYSTEM DESCRIPTION AND PROBLEM DESCRIPTION The drainage system downstream ofthe site consists ofCMP with diameters ranging from iz inches to 60 inches. There were no signs of flooding or erosion along the system within i/r,mile of the site. See the Vantage Point Apartments Technical Information Report 3 k ff above Field inspection for a detailed description of the surface conditions along the lh mile flow path. See below for a detailed description of the drainage system. Information has been obtained from a combination of survey,City GIS data,and field investigation. The onsite pond discharges across io5`n PI SE through a new ii inch storm drain to the new c,8 inch type 2 CB 38 at o.6o percent slope where the onsite runoffjoins runoff from io5tn PI SE. From CB 38,runoff flows through a new iz inch storm drain to the new 48 inch type z CB r,o at i.00 percent slope. From C�; 40, runoff flows through the existing iz inch CMP to the type i CB 8i37 at 3.gz percent where it joins runoff from the WestviewVillage Apartments. From CB 8i37, runoff flows through iz inch CMP to MI- 8i78 at 3.0o percent slope where itjoins runofffrom the Fred Meyer site. From MH 8i78, runoffflows through 36 inch CMP to the 7z inch type z CB A where itjoins mixed runoff from the Spring Glen Day Care and io5`n PI SE. From CB A, runoff flows through 36 inch CMP to MH B where itjoins additional runoff from the Fred Meyer site. From MH B, runoff crosses io5`h PL SE flowing through 36 inch CMP to the paved over CB C. From CB C,runoff flows through 36 inch CMP to the type z 54 inch CB D. From CB D, runoffflows through 36 inch CMP to CB E where itjoins runoff from the SE Carr Rd system to the east. From CB E, runoff flows a very short distance through 36 inch CMP to the type 2 CB F where itjoins runoff from the Kentucky Fried Chicken restaurant and adjacent parking lot. From CB F,runoff crosses SE Carr Rd through 6o inch CM P to the precast vault structure CB G. From CB G, runoff discharges to the Panther Creek tributary through 6o inch CMP. The remainder of the 1/a mile is comprised of a stable cobbled drainage channel in a wooded area. See Appendix A for Off-Site Analysis Figure 5 and Off-Site Analysis Drainage System Table. TASK 5: MITIGATION OF EXISTING OR POTENTIAL PROBLEMS The drainage system shows no sign of flooding or erosion downstream of the site; no additional mitigation is proposed. Vantage Point Apartments Technical Information Report 4 k ff 4. Flow Control and Water Quality Facility and Design EXISTING SITE HYDROLOGY (PART A) The existing site has no defined storm water conveyance features or constructed improvements. The site slopes from 5 percent to z5 percent toward Southeast io8th Street and io5th Place Southeast and upwards of 5o percent to the south and west. The ridgeline of the steep slope splits the site into two Target Discharge Areas(TDAs). Runoff from the onsite area is collected in the roadway gutter and piped north and west to a Panther Creek tributary. Runoff from the offsite area sheet flows down the steep slope and is collected in a series of catch basins at the toe. These outlet to a different leg of Panther Creek. The two basinsjoin in Panther Creek greater than one quarter mile downstream. Soils on the site are classified as Alderwood gravelly sandy loam by the United States Department ofAgriculture(USDA) Natural Resources Conservation Service(NRCS). Borings on site show glacially consolidated soil beneath unengineered fill. King County RunofFTime Series(KCRTS)till soil classification is appropriate for this site. The site is located in an area defined by the City as"Flow Control Duration Standard(Forested Conditions)." The pre-developed condition is modeled asTill Forest using the existing onsite basin area accordingly. See Appendix A for Existing Condition Map. DEVELOPED SITE HYDROLOGY - FLOW CONTROL (PART B) ' The developed site will be a combination of hardscape, landscape,and flow control Best Management ' Practices(BMPs). Grasscrete, permeable paving,and a combined infiltration detention pond all serve to , control runoff from the site. The alternative paving systems allow for the respective areas to be modeled as either a combination of grass and impervious or completely grass according toTable z.z.3.0 in the City amendments to the zoo9 King County Surface Water Design Manual. The detention pond is designed using KCRTS to meet the Flow Control Duration Standard(Forested Conditions)of the existing onsite basin.The pond is unlined and is allowed to infiltrate into the native soils. As coordinated with the City, monitoring wells have been installed to monitor groundwater levels. The design infiltration rate for the detention pond is o.4o inches per hour(i5o minutes per inch). See the geotechnical report in Appendix C for supporting test data and recommendations. All proposed cover types are modeled as impervious or grass till soil. The offsite basin does not require flow control as it does not meet the impervious area thresholds. The improvements that cannot drain to the detention pond, including the frontage improvements,are modeled as bypass in the KCRTS model. See Appendix A, Figure 3 for bypass area delineation. The time series developed from the bypass area is added downstream ofthe detention pond for comparison to the existing onsite forested basin. The proposed site geometry prohibits leaving the existing basin divide line intact. The proposed grading diverts most of the runoff south and west of the outer access road to the offsite basin in order to preserve the existing area as much as possible without causing erosion from concentrated flows. City officials authorized grading revisions which direct more tributary area than the original o.io Acres planned to the Onsite Basin. These grading revisions were allowed in order to preserve trees along the perimeter of the Vantage Point Apartments Technical Information Report 5 k ff site, increasing the Onsite Basin by o.i7 Acres.This diversion is compensated for by using the existing onsite area in the pre-developed condition. See Appendix A for Basin Map and Soils Map, and Appendix B for KCRTS program input and output files. . . . . Pre-Developed Developed On-Site - - Area 3.zo Acres 3.37 Acres z-Year Peak Flow o.o8g CFS o.07o CFS* io-Year Peak Flow o.i55 CFS o.i4i CFS* z5-Year Peak Flow o.zoz CFS o.i68 CFS* Off-Site - - Area o.79 Acres o.6�Acres �Release rate at the Co�„�str�am P�in- c`Comc�lia��ce DEVELOPED SITE HYDROLOGY - WATER QUALITY The site is considered a multifamily development. According to Section i.z.8.i.A, enhanced basic wa- quality treatment is required. Pollution generating site areas are piped to two rain gardens. The rain gardens are designed according to Appendix C.z.S of the Zoog King County Surface Water Design Man�� and City amendments with i8 inches of bioretention soil and an underdrain to filter at least 9z percent of the runoff volume through the underdrain. Trench Drain-io7 was not installed;therefore, Rain Garden— z was checked for compliance with the added north parking lot tributary area. In-place infiltration testing at Rain Garden—a confirmed that the o.4 inches per hour rate that was recommended for the detention pond is also appropriate for Rain Garden—2. Rain Garden—i has not been analyzed for the reduced tributary area as the in-place performance exceeds the original permitted design. See Appendix B for supporting documentation including in-place infiltration rate test results for Rain Garden-z and Geotechnical Engineer confirmations. PERFORMANCE STANDARDS (PART C) The site falls within the Flow Control Duration Standard(Forested Conditions)as depicted on the Flow Control Application Map in the CityAmendments to the zoog King County Surface Water Design Manual. Vantage Point Apartments Technical Information Report s �� . -,. ,...:. , .: :�. .. _ __ .... >w_.. _. k ff 5. Conveyance System Analysis and Design The conveyance system consists of swales, pipes, and catch basins. All pipes and swales were sized t,: convey the 25-year event with 6 inches of freeboard and the ioo-year event without overtopping. The analyses of the asbuilt condition confirms that the structures do not overtop in the 25-year event. Tre Drain—io7 was not installed and the pipe downstream ofTrench Drain—i000 was installed as a 6-incl rather than the original 8-inch. These construction changes result in a larger tributary area dr� smaller diameter pipe. The pipe has been analyzed using backwater methods to determine it� performance. During the z5-year event,Trench Drain—i000 will pass the z5-year flow without overtopping. During the ioo-year event,Trench Drain—i000 will overtop and allow runoff to sheet ri� into io5tn PI SE. This does not present concerns for erosion or other severe downstream flooding problems as the gutter line of io5cn PI SE is connected to the same piped system as the site discharge. The overtopping at the ioo-year event is consistent with the requirements of Core Requirement#4 of the City of Renton Amendments to the KCSWDM. Due to the shallow nature of the trench drains the 6 inches of freeboard is not attainable along the entire grate. According to the trench drain submittal,the installed drains have a o.97 CFS capacity. The drain with the largest tributary area,Trench Drain—i000, receives o.8z CFS at the 25-year event. See Appendix B forTrench Drain-i000 runoff and con�eyance calculations as well as an excerpt from the trench drain submittal received from the contractor. The longest and flattest trunk line,Trunk ioo,has been analyzed for backwater effects. The system in io5`n Place SE is modified to acceptthe invert ofthe pipe from the detention pond. Upstream ofthe connection the pipe has been steepened and downstream it has been flattened to 0.76 percent. Backwater calculations have been provided upstream ofthe connection point to ensure the new pipe profile meets the conveyance standards. All other pipes have been sized using Manning`s equation and engineering judgment considering contributing area and pipe slope. Backwater calculations are based on the zoo9 KCSWDM. See Appendix B for conveyance calculations. 6. Special Reports and Studies See Appendix C for Flood Zone Map and Geotechnical Recommendations. 7. Other Permits The project will require an NPDES Stormwater Permit. Vantage Point Apartments Technical Information Report 7 k ff 8. Construction Stormwater Pollution Prevention Plan Analysis and Design EROSION SEDIMENT CONTROL PLAN ANALYSIS AND DESIGN (PART A) The only stormwater pollutant anticipated during construction is silt laden runoff. Treatment BMPs should ensure silt laden runoff does not enter the City conveyance systems or natural channels. Check dams,catch basin inserts,and one large sediment pond will provide treatment prior to discharge. Stabilized construction entrances and sweeping should keep the City streets free from debris. See Appendix D for sediment pond sizing calculations. The sediment pond will be located within the footprint ofthe proposed detention pond. The sediment pond bottom will be set above the proposed detention pond bottom to ensure the native infiltration rates are restored to the pond prior to final grading. The required surface area for the Sediment Pond is 1,973 square feet. At a three to one length to width ratio, three to one side slopes,and a 3.5o foot depth,this area corresponds to a volume of 3,5z3 cubic feet. See Appendix D for BMP layouts,details,and calculations. STORMWATER POLLUTION PREVENTION AND SPILL PLAN The contractor may elect to install other BMPs to suit the current site condition as opposed to BMPs shown on the construction plans. These options are outlined in the Stormwater Pollution Prevention Plan report. The contractor will update the plan and report as site conditions change and add spill prevention � BMPs when specific pollutants are stored or used onsite. See Appendix D for Stormwater Pollution Prevention Plan. 9. Bond Quantities, Facility Summaries, and Declarations of Covenant BOND QUANTITIES WORKSHEET See Appendix E for bond quantity worksheet. FLOW CONTROL AND WATER QUALITY FACILITY SUMMARY SHEET AND SKETCH See Appendix B for summary sheets and sketches of the rain gardens and detention pond. Vantage Point ApaRments Technical Information Report 8 k ff DECLARATION OF COVENANT FOR PRIVATELY MAINTAINED FLOW CONTROL AND WATER QUALITY FACILITIES See Appendix E for Declaration of Covenant for Inspection and Maintenance of Stormwater Facilities. See Appendix E for Declaration of Covenant for Maintenance and Inspection of Flow Controi BMPs for the detention pond. 10. Operations and Maintenance Manual See Appendix F for Operations and Maintenance Manual. Vantage Point Apartments Technical Information Report 9 k ff Appendix A Maps and Worksheets Vantage Point Apartments Technical Information Report Appendix A KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND Part 2 PROJECT LOCATION AND PROJECT ENGINEER DESCRIPTION Project Owner King County Housing Auth. Project Name Vantage Point Apartments Phone (206) 574-1237 DDES Permit# Address 600 Andover Park West. Location Township T23N Tukwila, WA Range R5E Project Engineer Christopher Borzio, PE Section 532 Company KPFF Consulting Engineers Site Address 17901 105th Place SE Phone �206) 622-5822 Renton, Washington 98055 Part 3 TYPE OF PERMIT APPLICATION Part 4 OTHER REVIEWS AND PERMITS ❑ Landuse Services ❑ DFW HPA ❑ Shoreline Subdivison / Short Subd. / UPD Management ❑ COE 404 � Building Services ❑ DOE Dam Safety � Structural M/F/Commerical / SFR RockeryNaulU � Clearing and Grading ❑ FEMA Floodplain ❑ ESA Section 7 � Right-of-Way Use ❑ COE Wetlands ❑ Other ❑ Other Part 5 PLAN AND REPORT INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review Full I Targeted / Type(circle one): Full / Modified / (circle): Large Site Small Site Date (include revision Date (include revision dates): dates): Date of Final: Date of Final: Part 6 ADJUSTMENT APPROVALS Type (circle one): Standard / Complex / Preapplication / Experimental / Blanket Description: (include conditions in TIR Section 2) Date of Approval: FOR ASBUILT 2009 Surface Water Design Manual KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Pa�t 7 MONITORING REQUIREMENTS II Monitoring Required: Yes / No Describe: , Start Date: Completion Date: Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan : Talbot Special District Overlays: Drainage Basin: Panther Creek I Stormwater Requirements: Flw Ctrl Dur Std (Forested Conditions), Enhanced Basic WQ ' Part 9 ONSITE AND ADJACENT SENSITIVE AREAS ❑ River/Stream � Steep Slope ❑ Lake ❑ Erosion Hazard � Wetlands ❑ Landslide Hazard ❑ Closed Depression ❑ Coal Mine Hazard ❑ Floodplain ❑ Seismic Hazard ❑ Other ❑ Habitat Protection ' ❑ Part 10 SOILS Soil Type Slopes Erosion Potential AgC +-50% max Hi�h on steep slopes I ❑ High Groundwater Table (within 5 feet) ❑ Sole Source Aquifer '�, ❑ Other ❑ Seeps/Springs � ❑ Additional Sheets Attached NOT UPDATED FOR ASBUILT 2009 Surface Water Design Manual 1/9/2009 2 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE LIMITATION /SITE CONSTRAINT ❑ Core 2—Offsite Analysis ❑ Sensitive/Critical Areas ❑ SEPA ❑ Other � MAINTAIN NATURAL DISCHARGE SITE HAS TWO EXISTING TDAs ❑ Additional Sheets Attached Part 12 TIR SUMMARY SHEET rovide one TIR Summa Sheet er Threshold Dischar e Area Threshold Discharge Area: Developed Site name or descri tion Core Requirements(all 8 apply) Dischar e at Natural Location Number of Natural Dischar e Locations: 1 Offsite Analysis Level: 1 / 2 / 3 dated: Flow Control Level: 1 / 2 / 3 or Exemption Number incl. facili summa sheet Small Site BMPs Conveyance System Spill containment located at: Erosion and Sediment Control ESC Site Supervisor: Contact Phone: TBD After Hours Phone: Maintenance and Operation Responsibility: Private / Public If Private, Maintenance Lo Re uired: Yes /No Financial Guarantees and Provided: Yes / No Liabili Water Quality Type: Basic / Sens. Lake / Enhanced Basicm / Bog (include facility summary sheet) or Exemption No. Landsca e Mana ement Plan: Yes / No S ecial Re uirements as a licable Area Specific Drainage Type: CDA/SDO/MDP/BP/LMP/Shared Fac. None Re uirements Name: Floodplain/Floodway Delineation Type: Major / Minor I Exemption / None Flood zone X 100-year Base Flood Elevation (or range): Datum: Flood Protection Facilities Describe: Source Control Describe landuse: (comm./industrial landuse) Describe any structural controls: NOT UPDATED 2009 Surface Water Design Manual FO R AS B U I LT 1/9/2009 3 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Oil Control High-use Site: Yes / N Treatment BMP: Maintenance Agreement: Yes / No with whom? Other Draina e Structures Describe: Detention pond, Raingarden, Swales, Catchbasins, , and Drainage pipes. Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION AFTER CONSTRUCTION ' � Clearing Limits � Stabilize Exposed Surfaces � Cover Measures 0 Remove and Restore Temporary ESC Facilities � Perimeter Protection � Clean and Remove All Silt and Debris, Ensure � Traffic Area Stabilization Operation of Permanent Facilities � Sediment Retention ❑ Flag Limits of SAO and open space preservation areas � Surface Water Collection ❑ Other ❑ Dewatering Control � Dust Control ❑ Flow Control Part 14 STORMWATER FACILITY DESCRIPTIONS Note: Include Facili Summa and Sketch Flow Control T e/Descri tion Water Quali T e/Descri tion Unlined pond, Raingardens w/ UD 0 Detention X❑ Biofiltration ottom an si es � Infiltration may infiltrate ❑ Wetpool ❑ Regional Facility ❑ Media Filtration ❑ Shared Facility ❑ Oil Control � Flow Control Grasscrete, and ❑ Spill Control BMPs porous pavements ❑ Flow Control BMPs ❑ Other ❑ Other NOT UPDATED FOR ASBUILT 2009 Surface Water Design Manual I 9 �Uliy 4 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS ❑ Drainage Easement ❑ Cast in Place Vauit ❑ Covenant 0 Retaining Wall ❑ Native Growth Protection Covenant ❑ Rockery> 4' High ❑ Tract 0 Structural on Steep Slope ❑ Other ❑ Other Part 17 SIGNATURE OF PROFESSIONAL ENGINEER I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attached Technical Information Report. To the best of my knowledg khe information provided here is accurate. ! � 1 D 201 H- Si ned/Date NOT UPDATED FOR ASBUILT 2009 Surface W'ater Design Manual 119i2009 5 VANTAGE POINT APARTMENTS ��'f'!€ �'"�._w k �� y�f �i�"°�1 '..ar�:� +-�3"' ir r r,''e::r:_ � •_, ...T , _ � : �..p�� r:.'; �C�. tv�.� �`�� }�i..i,� � � ��'��7 y�` ,i � �M �` E��r=EF �e .� � �'� iit` �r R# • � . E�� Y �. � \' '1 M � y�� y � �R��'�t"-�`�` . r � ��'�' �`� � �'a �� ' .�' � ''� ' '�' �.-'�i.�� ,r- � `� ! �"` -d��r fi k IL� � �t-Js . l `� � y �r.E. � €.- w�`��' '�+ay '' ^C.r' Nf�:.�� ' _�,.� �� ; +s� �a . �-- -,f` :• q � � f- �i � ' �-_.i , �_j �E• w�rp�. , .�� ' + , • � E� F'��C... �. ��t � �T �� r r � f� �� •1��'•"��'�.` f ,� r , � e a�-F=�S�ee w � ��1� � ' '.s � �. . � � - 3e�:_. ; - , �� +. `� '� '"� �s�iT�sT F��. �,� �, � r.� +ir -•.� ,� f �$;i� ��_ � .:�,� �- � �i. Rt �� ,:�,� ,�-_:�, t�.; p� � ��f�`•'� � s f� ��'F,�� F f � � ��• �j�F��F��s �� " � �e f � !r ��,�� r _ �_ ,( '�+-�, � ;�. T` � � ��#`� -,�¢ ,�.`��► ♦' ��_�� _��` �w�'r_�•�_ � _ �., I" +� '„ .. � =��r - H _'„�►: •�_ _ � �, - �,.��l�.--� �, � � �� :F, ,.c��, � ��: � ,. , j - .r� ► i � y J i...C,[ ��. 7`:'' . . . , � � ._4 f.._ " j � U p�a� . � . � � 4 f. :,.�,�11ThT,r ..1.. . . . f �_+S, ''� �.'F 'a- ! '• . �} � �-`''� ,._�: *. - f` .f� �� t L-" ..�' �Ti _ � '-�F � . �_ �?� '� ! . -_ � � y. _ ��r� .{' � � A� �. , i �� ✓�.i��. d i � �. •n _ � � �.r S- r1_ `{• .�� .: �� j. . ��' � 3 i ' r .'��. ��f ai �q.� [ � L��*;�t { A.r� � 1� �,..�,.. -. �+ � ��yi(�« r,:� - .-'�'�. � y {'t � _. � z�� u �.:i. �l � �_ , 4.•,� � , , ,h �� 6�� ..� :� ,y..�3'� r � `.';` 'r�>� �'- p.�� '- � , , ` , • . �'- �. , y � _ �� RRT�� ' " �'L�t. t j �_ ,� �. _ - -§ �� y!�`t� �J�K�� .� J V "f ( I� M': � �y r ""' jr� �,�� . � m �'t T .'' (ti� .r' ��)� � ^ � f�E� . �-`� r c� .� �-T�~ �.�� A` � �j.� R'�� '��, F-�5 r�' � ��f i��t(4f� �I s F�"-�r.�� ` � � .v'.? � t3 � � ' �f; �� ' 1` �-. r*'� s�� ' @ -�l f 1 Li�� ,�' s� r�. � � i "� ,�d s�` 3'� �' c� � � [" � '�� ,�'i'�x,; � '�� ,."� , . } � _ �•' �� ,�E ��#€ , ` .'��1F'=7' _!e .��—'� j " """�� ¢ .��i j-�"� r�i'�'�[�`�� ` • - � -- �� _��rs E�� .� �E�' ,�� ;�• I�r�..r �� =�"s�: �� -�, .*' �� :�� :. �SITE ��x`-��,� ��- . �� :� -i�'+�� . ' il f S _ ,�r� n�'i:, � �.r`.'il r�} ' (E't r`- ��"3rT�i� ,�t`� '•- +r �" +► � ;.�'-.j,� I - � :��i r�"��r��:"'� ��'��r'e �� .r�� A � •lrr��.�'� ei� �' - � xi�xll'.- t�.�,��,�,� T_'�' }�i�� `�r. � +� �` � � _ ;._ ; •,' � �� , � r. •s�C��: �� Y�(YE.. �� ,�p�� ` +�� ,:, ` - ._ •�� ' : � �� :•��i��P` n..-', �r . `� � ' _ '�7T � � �i r�� :'•. �,:' ,, :�� ♦ # _ �} � ; �4-� J� � �. ��`179T�='_ � � � �.�ri {� � . . �,>Y �� . �' ; +,�t '�, - `" {� � .. �• :� � ' . °-_"-�-�. � ��.rt .-� ; �� # . . �' - ��s�� r'��' . --�t�r 1=T , �� '�� .�cst�! $'1e1JTri T�� ,� �-a� �._._� - . . ��+.� �t.'� f � '� "� � �� : �i tf� � ,�,;E 180T�gT �'�'��.i��.s.0�, ,�i .• �.:- �ar � . �'�� L � � ��t �' � � � � '�.`., �S; �s + pa �+�g��1� �`i��F��'R'i-' '� ��'�F'�.�t,� �,y�!�f E t� �!� �� . �is)-" ?q _ �� v`� '�� l��!� ��!o�J�� Y � +f '1� �ti" ,�,�'.��.� �. � '� �'��1�-- � ',;�,�' ',-�t�- � ��_��'��7yt�� ,�� _ _ .�_y �� .� .� ''• i. *, �•rr p`e ~t—� q� t ��i 4 ,�� 3" �i:�, �. ��µ s+ �; ��3.� ' . j• - � �S�`�4'��' , ��K.�� ,�,r_. �� .�F, := � ` - - STEEP SLOPE �� w ., _, `�_# , r � � �r ��-�= ;.�. "ry�� ';�� 9�:� !r��.� 1�]� �-`�ry�.R�� ' i��.! � �l��ti' :�s .G�aT . a '��b} _f ,+ xa 1`�. � r � —�� AREA T� s Q �.� ,s � ' f t,+ i5 � . s� ..�;- . � ��► . '7 .- :t f ' a' �aa��tv� - - � ,.�.r Y,�� . . '��} z�-F��. �` �rA- ''�i�, �'�`� �r� - '��- � ��^I��- . , � , , . �,'�" l� L �l�� R _ �Q"� �'1l7�2::� s..r l' .�ik, {! `*b l`'� �I ".r:�r`� � 3 � �i r -� �.t� d r� ;�, � _ .. �� ;: : �t�X't��" �.r�=�S+ �{ �,'��4 �S ►-' � -;�+�_- � ��1� ��G��l�i�,�,s��;i T��{ �� . s� �i. �`:�'� v.�t-..',�,,c �` ��s3x""." *.. iMP}�,.�c�.1�:Ci'G�'��i �� ....s �t _,�.�'��-��`_'�{��F�� .��.�, � �� `'�`.`�.'' ,}� � �i�'tf'��'��►'lr�ii� 4�� . . : � f a. T � � i PANTHER � �;�i ' r. � .., . ,._ r. _.. _ 4 . �, A �:f . I . : } . . ' ..' . � . � � ! r � �� _T 1 -.�f�.�� ' � _=1�9CT�� ; �! _ �� ' � �x :� z �*��:��Ti�;�f�i�� ",�,� l,� CREEK ��. � �� , - =a+7T�i ST � T■a � t�y �r��.��`4,:. ( I��f"� )1�1��'�E`�� , 6:�id�,✓.a ¢� '� 1 T'6�. w � j� , ' �c� ,;��l�T��1 � . J. . > - �. . v 1 , � ;� � Y,�, . � s� ��i�� `�� .�f�i�� '�T€_��,.l� ' >�„�,T i�Tw , .G� � � � ' �± `� ��' ��: '�F��!E f��'Y.�f�;<'�'!'• �_"-+'��t �< �� f _=� �r_r' �, �:_ - ..—� .,��e�r�sr ��. � M � �� i+f�Gr��n��s..��, ��. �!["� ,+,, a �� r�!`! 1 ��r� 6a�'= tR'�R � R � �t w!'` • �n_ +�`r, .� �'�'iii � k � -.�, ��`I�� !� y'9.�r�r _v �. .f � t " � �-�.t_�� .s��r•,-- � . . ,. �.l� � �� . .�,��_� .�. °� � - -- '��,, �-� o�- FIGURE 2. SITE LOCATION :r � �� '•._ r`:�� n �:":�' ��et!� :�rl��'� _� �� -� = �a '�'�,; r'�� .,,�, }.�a �� •�� '�#„� �l NOT UPDATED � � �'��# 6�� t' '��, T�''��. �}� � .� �� , _ ' �.��'��_':d�.di��:��=t�� ,��:� �� _,_., , Tf_ .. :.-� FOR ASBUILT �, � € � =�-;- �.� ,t _ ,, . , , � t�- �_ . ��s _. •;_ � � s = . .: _,_,,. ._ �,,,. �s 5,�-r� '�� -- i+w, ��;�� 0 1 � 7271t� '^4�� i+ � ` The Intormahor included on this map has been comµled by King County staff from a vanery of sources and is subjed to change without notice.King Counry makes no represe�tations or wartanties.e�epress or implied.as to accuracy,completeness,timelinesa.or rights to the use of such information. This document is not intended for use as a suney product.King Cour;y shall not be liable for any general,special,indirect,incidental,or consequential a � . damages inGuding.but not limited ta.�ost revenues or lost profits resulting 6om the use or misuse of the informatlon contai�ed on tliis map.My sale of Kmg County ihis rnap or informaGon on this map is prohibited except by wntten permission oT King County. Date:10;31/2013 Source:King Counry iMAP-Stormwater(http:llwww.meVokc.gw/GIS/iMAP) . *.t��.\t��`k�� ' �� -a ��-.�c:-�� ..............�':.•�. °a�� E :� �.�'� __._.._ �. ./ � � � ��.,. � // /__ _ _.._ � y' J �;ii� . � .. � ¢tc}'l,J' .�!y�-�'rL',..�� . '�'Y ''' k w ..v. � 7 � `�� :'� Yy�� r ` � ....... � ( � / / ,J N �'�.�. :f'� f;�.. r.•.•r.•.•r.:•'!.'•}?.�:•:�:•:•:•.•.. ..t��., � . / / /� ( ,� �' .� ...,... �:i�:�''�'''''�''�''.''.'�'''''� �' � '�,; � , ,��- ��.-; GRASS �` /( � �(� ''{; �:�:-: -.�.: : �,,.�:'�.::;f:..�:-:<{::�:::''''"':::;:::::. °.;,,;_ ..................� .,% / l ,,, � ll �)�)�jV , %;� �:�:, � •;-:: .�:.: � :;F;;<::�:=�;::;:;f:�:-��.�-'.'' � � � - �, - ; � ll,'/-,l'�;;r �r :-��::�.:.I;::k:; .� � .r.. � / ! I �/ �, ,�,! ,, . :��.�:��::�..:•��i�.,;•.-:.•.:.:_:�:.:.:.:.j:_:.:•:�:•:•:•:•::::::.::::::'::::::� �. ONSITE BASIN ■ ■ �f '� '�J� ' � � ";��I � '� �-{. Q��:��:=' � .. : � ' . ISTING OU1FA BASIN AREA � � I ��,'�„ . � � •.l.:•.. '<��s� �:�:; :�:�:�.;�:�:�:'.�.:�'��':�.�>'�:�� EX LL �\; �ii�,i'-' �N A.;t�6*�si:. ..�.�:�:�::'....•.};• • �� ■ � , �II � �.��,'.�`'�,�-,. �''t .:�E�:�:•.: �'�':� ��"`'ti`->:::;'::�:'''''�'''�:�:�::` (OVERLAND SHEET FLOW) ,;, ti� � �I i .� �.�.•'�::�:: ... �:��:��:•'•'•:•.•• :�:�:•: .. �'•' ::.,•.. " �� `I" � ��••'•- ';'(';::�::::�:: k:. :�;.•.;.:.•. �••••-..:�::':':"•• 3.199 AC � � ; I' �� :• :��: ::j;: .�.. :::/..=:•:•::•:•::•:•.•.•. ..� ' 3 ':�. � ,��ii�,� �c��, ��:� :��:='•. .•:•:•::�:•::•:•. ...•:-:•. �,t. � ��` � �+ � ,.�. :;�; ;:E;::; .$:;:.. .��;::::.'•'•'.'•'•'•'•'•'•'•:'•'•::-:':�.'.•: �� ,; � �� \ ,� 1� �� ,�,. � , :�:� •• .�.:::;;::::::;:::::;:�::;:.�.•� ( �;I �f' , �k��'�� o ,� 11,1 � ��,:�\ �:�� i�:�=�:�::��:�. .� �� +j� , , , , �,; � :f��:�� . . . ....... II I , � ��..•�: : � � ��., \` 11\ \�.�� .. . ��. �:�:�"�� . � .�.. � � :.�;:.:;:;:;:�:�::�� ;:� ' � 1 �� , o ` 1 .� `\\ ��\ ��',�� '�,-:� ";;�':',�.:� �, `� :'�..•:�:.�:�>:�'��:':`'::�:::::::::::::':�:.;: :�� I !�' " �� o �� `�� _;;; Y'_r: .x. . �``'�:�:�:��......... � �:;: ; � �� . :� � , \�� K `��;�� .��:�:�:. �:;;.5`� �: �:•:'�...;;:�� I ". � II �� z , . . � ,, •. : �� \\��'".�'_� ' '' ;�- � � _� f .�, .f �I �. � �` � � � � ,\ ��\�� :--�?- �:��:�::��::.: � . , I , . ' :-� , �,,, -- \ � � \ �� *��•�� - I �--�:�:�:�:�� : �_� g U, .m ��„ �"\�Q� �\\ '• '�:< } i °' ,, O �� \\��\�\\\��yp�..��r \.�\ .�;:`��,� . � ��.�,Gfi��4::?'�: � ..� .rn�g.l-"�.�1 � � \\' �� ^ti�'�.\��' �\ `?�'• .•�.•�•.�• ..'i. � .' � (� I � a, , \�� \ �\ .,: .,�:;..'; ,� �, 1 � i, '' �� \\\`�* �� .;:�!� . J � �-�--4-----��' :�::'�'�:�::�:::::� � �� — �� 1V�\ ;t\�� %,�i r:f �` :.�.:.;;3�:.•.� •� � ' : � , I . � �� r �� i�� .t1��'� � t��t m� N : '..•.'..':. •• . ...��.�•. . ,�,_� .� i N , S� � \� `1 � �v� ,n{l 1't'.. � ��'.'•�:'.':':'��:�:' • '•- '�,� �I �, �i 4D � 7� '•�:'.'•:.�'. '''' �. '' -1 ` � r j ....•.•. •.•.•. '' ��-. j y �� r � �r'', � � �,� 1: '•�'�:�: I I � ��,K-, ;�j;;'. � i ! I � :� { � . '�:��:'=.�:��:''' '.'.' � .'� � ;� � �.-x � tr� � r .. .. ..:�:��>�'�' .;.:.:.:.:.: a i I � �'C);�r,.+E� .. �, � i•. .r: .:. � .:- �� ,. .7_..• . ....�.:�t'1"�,.t��.�..�.�� ...:�}:::.�..�:�:�:� � I I c, OFFSITE BASIN .�,r: 'r I�, � �, >.�.��:.j. . ....�.-......,. ... / I �� i -- r 3•'i' •'.•9'::;:::::':'� .7:`::f•::' `� �a ' � EXISTING OUTFALL ,;: 'v,`�'( �: . . � ::.'.:.:.::; :::_� � �' � N �� (OVERLAND SHEET ROW) �, �� I �f 1 '},g,• :''f':::':';�:;'�:�:�:��:�'�::•. ` ; .�, I ,� �/J / :��•::�:�:•:•.:::•.•'• � � i��; x � OJ89 AC � r '�':'.':::'.':'�'��'�•:..•.....�.�:':�:'.'�....'.'� �. � � � � � � � j t 11f�� ' rt� :�� .:�:. '.. ,'� W X � � b�, l� / j ..�,., .... ..�.'.��;.;::�:�::�:::� ... ��,.,�.v.$ �, � o� �� r�,�,,�� I �r �'y�.��}��5, T>:.::f::�� ::�.:=.:. ;:} y ; : , ! �or�,;,.�,�.� � ' I`+r�J'k"\+'.. '. � '.��.'�''�' ro wwa M�N'�a M / �u�am aw 1 � •�c:+.•.'.'.•. oownt � � � � f / �; .C .=�<��:�:' :;� , �� { � �..M;;�� 1 �� / f j "� � ..��.�.�.�'j�� .. . ... ':�:.X:;" a •i� � � �' �° — c> r r �i r, + '': .. 1 .. (ti� I � � � � � on.m a� �� =�--�^'..—. ; " ' �� " / �', 1�+`�'',, ';� � �� 1. F �� .�` \ _�— ________— _�_ -- __= r � 1� —�-- _ � ; ' (if��` +� � � �� . , �---�-- — --�-� _� _ _—_�_— -� .� �� : ". i� r '� ,i��'�';� `� ...� .. k ��1 �� _�� , -� _ _ _- _ _ ,� � � II �,Q` , � j .�: '`�' �:�:�•�'. ` :.-�-:� .(.�, �� _ _ — _ , — _- _-- — � �� " w > Z ' � � �l � 1 I�l' ..:-'::•._,-;::::::::.. �:�:�- ,� ,,�� . -- °�""" _ . " — �. � �� J j, :� , � :��:�''`'`:'_•:• � �... •'• � � - 10 'W 'Pt? 10 � ' ( •• � __ _ �� / P� — ' I�f I � • � •� w� �. Q (� ""�' � �� ( �� 1�� ,; � r � � �::��'`;:�:: '� ':;'.j:':'•�?'�: ',' � �� = � — �,.� �ae�on��sr � `� � � q � �E I 1 'j��',�� s�.�. ..:r� ; �`:�:.::�: `�x -4.�:':� .::�:, , . ,s,,, _ _ , �.,� � � � M � �_ �I 17t: �.�:,, •�--- •��:L::;��•...�::��>: �=:�•��:�:- .+s,:W�. — _ E,i9`„sT — —�— _ _ �� /�+- �y i � �'�:�.• :•:•:•',t:•::•:�:�::��': •.;.;:: .��'•:•.. .5-,-:t. --�� 's++ � O (`'j]y� �t � �_�;tiv'r:��:�' �:�i�:�.. -_ :G,., ..,..�::,• � ✓ � --- - � '�'• � :�€• :f..i.:-.i-y--�'^ -- � .,C:.. '•�.. .� �� :� �•. ��.� /��.,, •:�. :�s�: ��i1 .�:�, 1 •�f - �a�: ��:. ��:�.. � I ,� � — '.^1. '.^.Y�.'.'.':` �.'.'.' �v.•.Y.Y• `.Yh�TAJl4.'J'{�'.'.�...�..�. 1 �� •"�E-ewi•'•�•' wi � •�. •.�'. •.�•. i � '.i. -.-s�'�. �( ..-J.'.7L�'�' �♦'T�• t - ( � � "F: :�:: .,.,� �•• .�-.�'�" .:�3�-''�':tr•..^".. N '.��:`.'"`�'.'�h. .-.Y.. .'�-r.Y'r'.'. � .'�.. '.i'�.'.: Y '-}- .-r��.^��.". � � ,.y.:.�.....'. �.� 1 ��: ` :i:.;�`;;; :�c.nna,-:. _._.�r=' .:h. ...-y. � ��•: � :>ti;•'• � '''i: +r{: .�.•._.• i •.�.-r.. �� . . .•x,-rr::. I �-. I . . .. .... .. . �4.�'C.'�.' . .. . � �� i I � � :`�: .--.•�:::�. •• ..�..�;:�.• . •�• :;�.--:-- I � :��: •;:.:: •.,.:�:: _ .�.,.=,.t.�.•::,�;r.--:�:� __�_.��._.�.---.-- .:.�..�-.•--- :�� -• :�'".....' 1{ I�. ��:`� ..�::--- .___.r...��.---. �.:;=:. :.� �- .�.: �- i �:�. E. :;�: �.��: .;:<.� ..�,:_::;-...� :��..� �.W..� � �.� . __...�:�--.. �'"�`:�::. .�-�.�—.... . � I 'i ��. -:r< �._.�.----:� .�,-. :.�' �� ..r-, .�.. .�,-.:�:;: .�: � ��: �I t:;;:� — -_.:�:• ��--.,--.:--•.::'�:rs-- .�_-._.�--- �.�.,,-. �.� :�.:� . 1 ( �` � •'%�'. .r.-^� :•.�,'r.:'.. r'.�:--r •.=t. r � .�.-.•--- .,..a� '� � �, �. a. Y _-.-:t'.'. •.�'.'.'.'.' .��JN'�:^�� '�s / — � •'�_' •Y.•—_... `i,r'.`..._'.'.�` C�. ( -4^. '.�'. i 'if'�.':f.' � ':�` i � ..�. �� ::. ,; - :�.--- .Y-:�•--=-:�="- � � ��. :-,�.. .•T._:,��.�-�----.• � .�`�:•'r.:��i.:-�-'.r':'.-.�. .f<:�. rc u ..ou.e� C I. - � .�. � � I. �'_ � 11 ---:;-;� 5 � ��:�� =��:::��. ��s': .�.. ., - 4' --',*r.-�-:•:•'- .=rr..� ..--. :��-:-:- ��;��:�:-� ",'• •�':�.'�-:•i�-'•`� mlw/�A . . . . . .. . . .. � . . .. _ t 1. C: I l Cla •.�'...�- � ` r <- :� •rr.-.�.-.<. � �.�.•'... 4 �. � �� , � - — - -x:��-,. �.-r�:^' :'�A�.�:�..�` I 1 .•.:r..�. d �:•:�'•:� .�-.•.�."_. I :C•: - — .�:::-:��:- I �:�.:: � ' �. �:'�C: ._.rr.----.. — 1 � •:l% r.-:��. �:�'r.-:'—:'. �.•::*'r:�.j;..:-�;�.-.°.. •:,rt•.:C: 1 l 'Y..'.'.'.'.:.:Y..'.'.''.'rr. ,. - __ . . . _ ; . .. ,_. .�. := ��.�:�>.�.� 1 ... _ _ ... ... ` i ,� � ..�`<:�:�:' �� N 0 ` . . . .......� -.-: . .< ......... �..� ... . .. .� .,: ............< .. .... ..� � ........ .... T- -� 1 �. ... .. ....... ....�.�.�.-...�.�.�. >:��- :�;= :.� - :,��.�.�.. ._ i J ` 1 ,, , . � .��....�..._ ......:��.. �;�=::, �:;f ,J --,;�: ��:�.� �" .. i jt l � � , �...�. -..� ......... .........�...•_�:•:�:. .��'" ::r:=:.•.-..:"�;.�. .•:Y ._:.�, .�:.�---- ._._..�:-:.•--. ...-� j . � 1 1 1 . � � .S1 . �. . . . ....... ... .......... 1...'• .'if. ..Y'.'.'.'' '�1:'.. �'�t"�..T, �'.y�r'.'l�.. .�mf< .'�. _� . 1 1 �-�i ��, 1.....+.. . �.. .......�`...YY^........... ..... ..1:'. :.'.�r.. .�Jr� .Y.. .Y�...'...'��.'.'••,.,j1'�+ �-.+ -f�.. 1 11 ,, .�. �.�..�:�:-:�:.�.�.�.�.-:-.�.�.-.�.�. ,��r-:.: .,,,,-:�:::............ .:__•�,-.. .._..�:-:-;�>.�.. �.:��;:�:�;��, .� \ \ 11 1�,,,��, �.��.�.. •.�1--r�:�:•:�::::.�:.�:.:t:.,.,.,.,.,,;.�..�:�.................�:: �.�.�:. ��..,_:�:•�.�::��•_::.�.-:� .� �:�""`�: ,.. — \ \ 1 , , „ �.•, .ti::•:•:•:•>;::•:•.>:•:•:•:•:•> .:�,:.. -.�•••.••�:r:•: .•.T:•.•.•.�.•,.:. r--. .,.,..:�.. ..�.•,•.. �.•;4<: ^f�, _ ��l ., � ..... �r :r:.:: ��::�� ' \. 4• .��'.� •�� \ i .:�=t..iT ! .�.�.. � , .�ir� •��.� /'� \ 4'. •�.:J:�- � .��.� �,�,� \ ..�... .�f�.. .'�f. \ ::•r.•:• \ « � ::�:=: ��: \ i, �� :�:. �• •� � :�•- ��•:.•� �; � \ \ ��:�•: •:�:�.•.�.-.• �{, , \ �y .y�:��-`:•�.`":�:�:�.. \ �X.. ..._... ` „ ,' :�:';�.•.•.�.•:::;�:'.•.•: .'E. .�:Y. �`��''� "_''e.•T' � 'It '.��'•... � .�'.•.'.•.•�•�•��'�:.'.+-� .. . \ ��, .Y' '•� - �2 - '.'ti'. 7� .�r..'. �� .-.�•:�'• ,�.� . 'rr'�L'C" . .'it�"^.' �'Y..'.'.'.'.'.'�' \ W '.%�:' ��t.� �Au ' '�:'.��.'.'.'.'::,•.'. F''�'•".'��. � \ . �.� •::�. _�':. .�� '�• � .�.� .�-. .•.�:-: .•�m a � \ �J� :�:;�:•. :�::1• , �;% =•,•':�:;~ •�- :�i.�•' :;:�:•.•:.•:>• 1� _ ..��'�.�.•f. .�``� ,. •:--�•.•.•.•::•'• :sr: 's. •.�:•:•:•:•:•:•:•:•:•=:�:�: , , � •', '•.�.=.'o'i:.•.:' .•Y'• � :r''':}•-�it... r.�`: :r.� / � . � 1 � � � ��':�:� .�• $-�'..�.�: ' �:::::.�.�:.�..�;::.:�:.. .s�. 1 t \ � •.«� �:-�:.•. •-� .:r-.. �:::�:�-'.:.•:.•. .�:-:-� -� ��=:-.••• .d. � �3 I � .�::�� ,�i ..�:..: :.:�, �, „ � ` ��. =�:� .�� .. , � ..y-: — � �.�.`�:�• ':'�'7��.�' i , .'Y..'.'.'''.%r:• •�r. �•l.'':'.Y'�'.'.':..�..�.�.�.�:. J"✓.. It ` �• ♦ ♦:. ' .� •t:`.- 'X':'.. 3'i '.Yi'i}• / ��•�•• � �, 1 t` •i%!• :��':�'.'� .. ..�r...' � .•r. •• -'::. .;5 ��. :.:�:. .o \ z •��• ' , � ....:--- _ , .....:. ... _ :. ..:• '.'y'.�.'.'.".':. /� '.'y. .J,. � ...... .�....... ...' 1 1 . � .;.... . . .�.•. .. �':•::�:•:•:•:� •.•>>:�:�::�'."`�• - \ .Y .:��-.��'••r+.'.. - ",�A''...'.'... .'�i-.'.-�`. .-.�. '6 ' '.IYk�• YMVI . � \ a�..• � . NORTH ❑ \ 1 1 \ \��. •.:�-��:�.. � . :�::�•:�.-,:,:�;;�,`..:•,. .:�i- .. ,.-- I i �-�:�.. :�::�'�� „� . - .r I � \ :-t:��•�:�;:��:�;:;r�:� � .1.. :�>� �.,-�.-:�_.. ` .-.�. \ � � � \ •.��:=•'.':'::•:.:•:.:•.•'. _�::r�:•:-:•:�:�'�.-• �:;�:•:•.•.•.•:-::�;:''' ---;.;;�.•. ,,:r._:.•. ��:yt.. i .,� \ ��:. -r \ \ ::�:=:;":�: ::r.-:�.: . ` \ '•�'• .r.. :r.. � � � •::;!�:•:•:•.,.. - �`�� .,��- :��::�: _ \ `� - ..:�::�: .f:�� —, , \ � ��r:.�...�,� .�,:r:�`�`��-:''''>��:�T:��: � \ \ \ �. -�::. r.•�� =f-. �;:�� :r� , \11 •:�...•.�.:ay.'•:.�.•.•:.:.•.•.•::�.;:...-.-�; ::` r: � :�::t....,..:. .,�,� 1 � .��. :�:��=. 1 1 � �.�:�.. � �'.. \ �>�.i:'��.�::�:�:�:��•��= ..r 1 \ ��.�.�r�. ��. \ ,�. � t• :� �-.:r- .,..,a� � \' - �� 1 - .�.. �: :.;�::•.,.,.;:�•,:.,.:.... .�.J:<<-:.:.•'• �:�:�:•.�.•:.•.•:�:�>:�:�:-:�:�:�:-'� ::i. � � �� .,:�' _... \ �'��::.• -:��:•:�::�:��' ir�: > 1� \ .�. .,� .�.�-� , � \ /� �:�:�::'�:•.•:-.. �:�.•:.•:.�.�.•.-... 1 � \ \ \ �:��.�:'' .,1...•.•.•.. ::::;�...•.•.•.•:•'•' ...•.. .,�.•. � � r'---'�— ., .V'R's�._.^'�•.T:.s.%!..... .��..• .I.'�...'::.• �r.. .:�. !'f' . - no� iaw \� � 'G.,,• ,�.rr:. �•j^•�:?'.��. -.•r:4:•:!�•:yr. •:•'r..•.•.•.•.•.•.•.•r• .•.:.rr-:''•:�� ..:�^ ':.�.��.. I ' a �� \� �, + �:.�;�;:.:,:.<:•.•.•.•:.•.'.. ••�•:•:•:•' ti.�%t'•:•:•:•:•:•! .::'rr:•:!'....�,. ,�.�ti-. ,.�. \,.,\ s � � �,G.�,�. � �\\\\ .�.. ,;r'.•.•. :•�: �:�•: � , .�.. �. i \\\ \ ��_. �• .,,• ',�r•. :•r: :;;r.:.•.•:.;..;,?.:.•.•.;:•:.-:?�.........:...•..,• •.;-- \ �% --- � �� I �n avca�e� � \ \ \. �.�. . .'..:J:'.. �� . .</�:.':.•,�:_.. .�^ .1.:.'.'.'.'.'.'.'.'. � / b�M�Y .� �� \,.�\` � � `.��'.'.. ..:.+.. '.'f.'.'.'...�'..... .,7l.. r,/r'.'.•.'r.' .:r` .:.=/ . � \�� \� ., `��,� �-y- -r!:-'�:�:�:�:��:•.�.•.•.•.•:�:�:<�>;•:. •:�'•' ..�:�: .��.. ..�;.'-::�r`' ,µ, v ' . ..'•':....• ,, �..r � ( np, � \ \ ,:�� . ::f:;:•:•::::'�'`:'::�':.•.•.'� :•Y.'•:�:�'�'� :<:i.-.�.•.•.•.-.•.•.•.•.•.�.•.. .t: �.•r.. �•.�;-:.:�r.. .r.'.� �� ' "°'a i i�i `�, \ \� \\ � .��,. :•:i'� •,l':�:�: .�.�:�: .r- ��y��r�.•r"r-t,�F�' { i ' r"r • \ , - � . . \\\\ \\ \\ ::x...•...;.;.. �.�t'•:�:�:::,�' :.'-•. ;.'.'�-��'�-"..J;� ...r:;.: .a-.:r.r+ � ��\� .. '.�•'�:f...�•�� .'!`..8..•: :i:.:.l�f' M�'��!!�► 7►`!..'�'.'. ��.. : '^.a�,;•,_•�S%�>r. .,.yv.;::.-.y.f. a.r.. �� \�\�� ''��.. --, �.�'.'�c:v'� ' ��r.,.. •'��•.•... • .,�,are� ''' .{�� .:�._ Q �� ,�: :a.. - � �,• ;;,%�:-�.'.�:,•'- . �v:�..r.-.rr,.� �i � � ••�' �•'•'• '•'�:::<-{:..:�'' .-.}'ra�`�' •'•t'••;r! ::l•r.^x' �X� ,� W \� 'r�.� �� \ �.. _.:J.�. �.?f.'.�.•.•.•. �'�\''''�. -�r.",-.;: �..._._.� �t..-t^��J�t. .' .,.y,��•� / . DRAWN BY DESIGNED BY � �. �� :�+ �„ � �. �:_�:-�°�:.�.-.-.�:1-,��:�:��--- .,:�:::.. :�.y��+"'��_ rrir� p„ 0 30 � � C B C B � � �,�.�'�:: ;�: �: �;�:.,� . �.. �, � : �.:�. �::�:;;y.�-�:�� \�� . � '` �`�� ::::::::.:�: ��....,�_........ �^ � �.� .J; _ ;�� ;� �..��;: .. ,��:.:. �.-...T �:�� _ . _ ._�'=, .�— �'`-. �. � ..:_.,... � � CHECKED BY APPROVED BY �� :::3 ��:�� , ��\ \�'�.��.�"�. _ ;� —.�=--�-��% � " a i , � �. .-....�.':.• :�:. .•-.A,�.�:::;:r.;:� _ _ _ , � > AGC AGC _ _ ; ` �, . .. — .:� �. ;> ,�.;:., �, �.., Y .'�;_ �..��.z�� ,p�' �_�. -�- — _, �%, . . .. _ .� � �-� ; % DATE , KING COUNTY HOUSING AUTHORITY SHEET o � �7 16 2014 Consulting Engineers N � 1601 Fifth Avenue, S�;te �60o NOT UPDATED VANTAGE POINT APARTMENTS � _ � J 0 B No. :113188 S C A L E: Seattle, Washrngton 98101-3665 _�� 1 " = 6 0� (206) 622-5822 FaX (206) 622-8130 F O R AS B U I LT E X I S T I N G C 0 N D I T I 0 N S = u _ � _ � , � ��.: .�� 3 t��.._.. �% R- .?Q'- � 4�.a�� ` �� ' � , ` + ��r � I Eey�. _ "_ � {A� �- � r�� - �� .»x f �.-� 1 � � � '<,� . � � ' � � a-r .. .— ..x --'c � .._ . . . '. ....�.. •� ';� � � 'f/ 1 e� i ' � � f//..,. � ..�� - � � PERVIOUS LANDSCAPE � � u� ` / t/l /� �l�( ��r, �� y ` ! ^� � �' � ,�� N� `�r / � „�ljj ��rl�f ;:�. � j { '� <�J � ' � _ � �`- � r+� o� � arr w o f � / A� '` OUS J � xDETEN�ION POND K��e�1 PERMEABLE ASPHALT PAVING � z A a o i PA�AE- � " _ OFFSITE BASJN , � , , ` . 5 A •; 0.873 AC _ i 07 C � � PA$fi6�A� l il ;) .. , . ;�, E:� IA ��63-AE �� GRASSCRETE PAVING Q � 0.600 !�C ,'�+ `i�i � ' ''4 '� •; � ; 2.146 AC � ��n `,IA 0.022 AC _� y' i _. , '� � '�C .� �j ,TOTAL��36-Il� � �- � ��TOTAL��A6 ��``�\ � � � �� \ \ ' 3.02 AC r— �� \� ', T d,62 AC � � \;� . �.. r:s�„ �. �:` 3 ' � � �(SEE CALCULATIONS FOR �__J CATCHMENT AREA z ", ,`� ,�\'� _� . ��. -. �111 b � , �,� � `- ` $ - �s PERVIOUS PAVEMENT CREDITS) � o '` CITY AUtklOR1ZED ' �; _� l�p�j/gjJ ' � . �` �t�- :� I � I _ �; GRADING REVRSION � i•' ASBUILT TOP OF ONSITE DETENTION BYPASS AREA � � •,� , •� , Z �., F POND � \ kY Q,> � � �� Q i ��i �` ��, ' 1�CONS'�RUCTED � i� �c � � g, � +.i: t ��-� �p'_ ■ ■ � z t O �� - `. _ ; ,�. � � r � BASIN AREA "' a , �� CB - i06 ' � �' ONSITE BYPASS ■ ■ ,�, �� `, , '�±` PA 0.�03 AC d ' PA 0.205 AC o � � ,�, �� - lA 0.021 AC i IA 0.147 AC N � , ' 1 CITY AUTHORIZED GRADING REVISION r O , �'_ � — ��J ..,. �: � �i � � �-` I I,�.' .,.. + r � '� �� PA O.DO6 AC' � � � Iil�� Q� ' � $ (; 1A 0.045 AC ' � ' / / � RAIN GARDEN - 2 -kg�-3{� ASBUIIT REVISION � � ��= � PA 0.164 AC � `i �� ,.��,,�l,J, , � l / � r � �� IA 0.286 AC �> �� '� - ' � � �! �� , ,� ; � � o � �/ �,� � �// j � 1 � � �e ��a� �, �` � � �f �_ � � � i' ,�� :�, f ��`��y '' I �, J � iil. �;- ' �.�. a .� �� , �/� 1� ! f '�, � � �a< :�c.�a r ua a+ r9'"'� � / � ear r(niwnv --�m--�� c > � . �I w�m J / t , � �� . �'. .t+I�� ' w�i�ni MM�O w�i r v= � n��aw ! �- �-- � � t,l > `�= ; �' � � o � � �I � '� � �� , �� RAIN GARDEN� - 1 �-�_ _= Custom Soil Resource Report Soil Map _ N � <V � N N N � . ' � �� '�i�fl5?n 560?AO 560340 ��l(14U0 560460 660520 5605A0 47°26'36" a a 47°26'36" �i � ��i'� � .�+il W� �� , �� y�� M� �A, �� fi� �( ,� - a �nnx�� '�� 4 �I��; � +� ,4 , � . , �.: ,� �� ,,� ,z � I _ , ,. , � y� � � • �. �'��"� ; � o � , o � � �`� � T � � �' _ �""R� � � i�� k � y �� . � i" � � � i I�Q") N y N IM�1�� .. �1� � N '� '�. � � I ! �'�� . If y�, Mt y T : � 4 � -•.' . � T � ,�� :;�r � . , . � � � � ., �,. _ .b� f.. o — � , y � , . ,.� �. ,;...:. _. ` - .. � � � � �: �, , " �� a 7. 'be". N �� ' "'' � ��" ° �� Z C , � ,,; • u a � �� '�� "� � �. � �' � � �a�,�.�. � 0 � � r � _.��..,� � � � � � �"" � ; �, � m � � D � � �Y: � �� , �, � � N � y '�� '.� �' �'�`� ,�,, :�+� �°."" �. �� D �/ * ,,,, : �11� .+�wiM �+�Nr� , �! '+1► _.� • ,+�,�. � � ----_-- —- C � � _ � ---- ,�, � i�r � r r � , � � �� ' �..� j N 0 � p Q y� �� , -- � N � �� r �' � "� — � . � �� , �� N�r ��, �, + o 'ih � �* � ° �, �,� , " � o � ��,� �' � ��, m�� i �... . � a � � , �.� � .. '��. �� . � . v ., . ..,. ,... � ..�� , . d' , v MM� '�� rv �i n N ° � } .b � �Y N . �� •., .... �. .ii�- , �, .; � � '� F . � ' �i , ...� . �.,1.,. � � # � �; . . ... � � �i � � � � � 5 � n. , . � . �µ � � • F � ! f __ �. .,Pu ry� t � d �}d..�, f f}� �tJ�. . W � '� �`� �XM�;�.u»iB'_ _.�ji� ,.. � . .�., —w.. � .. ....�� o .. ... ,... m. � . ., o m . I�� I - .p. . p � . t � Mp ,. a" ....' Y � �� .... ..'.' w ��IIR�fI�� VJ N � <... N � ..,�n��, � � ,: � N � N �: 47"26'23" ` �' � + 47°26'23" 560100 560160 560220 560280 560340 660400 560460 5Fi0520 560580 N Map Scale:12,800 i(prinled on A size(8.5'x 11")sheet. � �I tV � N Meters � N /� 0 35 70 140 210 � �� Feet �V 0 150 300 600 900 ;' i�i►�� - s � � '� - �� , � MH B � - `; : MH 8178 a � � # _ _� ABOVE GROUND � v� ABOVE GROUND CB 40 » � 12" SD � � �`. �'� � �� I `� STRUCTURE • � � STRUCTURE TYPE 2 48 ' -.--��. : � � • - � CB A ,.� � MODIFIED PIPES � 3 _ ��,��_� _ .. � �� ; .. � � IN ROW ��.a - �:�.; � �__ r : . "� TYPE 2 72" � 36» CMP 12" � ,� �,,� - ; , J � CB C � ��Q'�� r� � _.:_� --�, MP� 12 CM P vr w, �;� � a� . , � � . �.�._...� _�. Q UNABLE TO 6 � --. w,_ .. :_„_ , _ _ a , � a�. � - Z _ _ .�. , � � . _ _ � : . ,� � �� W : �ocAr� 3s� � 105TH P L S E �� ce so5� ? :� .� � . . . , � CB D CB 8137 _ . �- � TYPE 2 54" � G�Q v� C�P . � '�' TYPE 1 �_� CB 38 — TYPE 1 _ � o � � � � '�� '� �+'w',�'`� �� `��'�,,,� � TYPE 2 48" i - _.,12„ SD / r, � � '�'� � r�`�` • �:� � �� t� SITE DISCHARGE � i _, W � �'�► � n ` �- � '� �=-�-�..._ � POINT I', , i � � * _ , � � �`,. �, - � � , � � � 36 C M P ;.- `�•�a � . r � _, ... L ` �. w". _ � � , � k. � � i *.`y t �'-,f I •� 1 � � � � �I j � �.� � + � � ` � � � �� i - _ � � ��/ _- ll , � � ` � ,;: � • � � . � � , „ , _ - .� � �_ ! , � � ;"�,a�r; "r-'`' _ y � � � • A x .�t ' � .�► - � � f ' �` .� �� CB F ' __, . .� ��-�- .*:;` CITY OF RENTON �`� � � ' '/ N _ � CB E �� TYPE 2 ' � ..,`]�,�. , � GIS DATA � � - - - / : ,-. i .�_ �` _ �f a"F'� +` . - .� ,; . . . t:_j � , ' ( � N - . �^ �- � TYP. ��' :4 . �- . � .� . ) � , . . , � . , - , , �� ;• t �-�.- ,. v � �-, °�� - . _ •_ _ ` � � �- -�_. +' � . � � �, r ��'a.'` � � � �' a � - � ; .� , g - CB G _. : _ -�� . � � � � . - . r�... � - . ;� y . _ . _. , �.-. . .� .. .. - "�;: - = a_. ,,,. .. , 3'. � " r . . r c' r . _ - ., . � ..r ,.. �`! � � � .. ,. .. _ _ p.. . . N . . � -. . . �c.. . ;fi,. .: � . _ �- � .- -__ " � .. . . � � �� . � ►��'` � � � � . ��. ::�. .�. �, � PRECAST VAULT .- �� , ,..�:r . � � t �� _ , ., ,� � � �.. � � � ��` �` _, .. _ • ,� �:,,.�,. � _ }': e� �� ,� ' . ._ � .� , - ' '— �, l- � `" � n.Y >. 4'"�`f': -� — - q .r::�'F � l�� . . - _ � , � �.� �rs`�r' . '�� ,.�' � �..r. ��„�!�" w ,� , ,� .,� JUNCTION ;� � _ . '�'�`� , w �r�� . �. . ,.� �, _ _ . . , � �_ � _ �� S�s �-�.,, — t; � � �� • �� . . - - � Q r . "- , ,�-� �a�- _ � �� STRUCTURE _ _ �� ' ��. � .r _ ,. _ _ . . � , � .� -� rF'�.�f ; . . ,�K� _ � Ti�3 �.�. i + j "s �• � .'.;I �.�� ..�� . .+ Q ' . -,} . .: , , U t>' 1� t �`�: ♦ ti� ,' �' � . �N� � ' /( ' _ • � �. � � . - , • ��j:.�.' fA C. .. . . ". ' ,.�. � "�.�� M . , ,� �. r - - � � �- ��' - � ..,� .> ` - s ti: e. - - � �.�r: ,, . e � - � �., � 4% '"„ �! r tS'� � „ �`,AR,i#�� .4--� , i - i - as -� � * �a. � a ��; �'� ! � r _ . . , I. .+dt - � a� . �.:�, , .� < . . . II - �. � � .( z � +�` { a,F.�, • � � . ` , 1:. 'yi�� .a,�y.,�� w. �� ''�� r� - � '�' �`'+ti . . . _ . . . , � . a � . �. - . . f :_„ _. -.;�.:,. n t. P � � t - _ . . . . c o �°�+� � �„ - �#s;� •�t__ .�, 60 t }� �..4 � � � ,� :�� :�,� � r — �.- � tia_ , �; ; - � ."� ,� `.�""�''''� , . � �,. _ � �fi�r ��.�� - CMP _ �, �„ � `�,.G Y � _ �_ �_� � . �. s , ,�,. ,, �, � _ - _ ,-�. ' �.� , ,. � s �. "'�� .� � r`+�d s !'�yi ts':�r f r ��}��. ,,,, � .. . . �.., �. . C . " . , . - - ' � _ � . .. . ��i , . � ^ . / ' p�� ,. i :.` yp .. ��.4 ,j +,� ' �_� . �� ` .. w � . �d. � . . � �� .'s.\ `. � . r . r ,, , r � m �.-!., :�:�. ♦'`_ r.r� J � \+<... 4- � 'ti�.. , (4.. �� . .i _ y:t7%1� r. �.,. �i ` .. d. _ . . _ � �: - . � r � '. �. . :� a. . ,�- . . — ' F/_"� * r . e . j� �♦ � ' � / ��_ ..�� .�,�. ,�r ,.I�, �s� ♦�_g��_y• �h�'- . .;`y,st -�` '"4'�: _ � � . , ' - . -i .l. ��.'-' +�, . .� �_ : , O X '��= ti�E... E I '� ._.t� a� ' �:. ,.s �.e, . 1 . .t'.�M .+�� {x •� 'V" _ A a t ,p=.' ~� 'R ' :��'a +_ ;',�S � . u-� w � :.*�- C�:="��-� b` '� y` �;_� �-� �r�`-�� ' �� , i "�C r � �, �e .. _ _ � : . � m s�..:< i �'y� ..- s. „ � _ � . �._, � , � - � -_ � •€:,4.t - ' ��t+:• � ..._ �'. � ` ' �s�.� ;;",; 'F� '�C;_: �^.s�-.• i � - - — �4 -- ._ . ' - >'� , ..:, y�. ,. . _ ..._ -• .. ' '.. �';,'-.-.. . r� , .,=' 4`'.,, � -F•y�.a � �)r� ' . � � I + . . v; ._ �. . , . ' yy� f � .. .� ..; • � � -r�x . ' � , i s��._,,�i �:�_ . .r'i+' r; � ;- . ,�..`.. -1i•� t11�-..�.r- � '`-�� <.wr` �:,�-�. �,R-� Ai "�a�a; "y�r"` �" .�:: �#'. \..... ��ti... - : a� �� :� _ .:.� :� . , � � � .� �. _ 't`. '^�d� .+�,� . t . . �. _ _ � _ _ �' �.�G�� , i . � . _ .� _ w l.��:.ta�a +�`t � �,.' m� � �:` _ ., ,. t > . ., _ . p X .�.'�' -- . .'. �,s"�� q•.,-��_. _� „u. 1 ._ , . -0� 3: � . rt-�..�E�y�, . . . �� +,.�.°.- ' a.:� - -;r� - � - � � � . �.�. �pS�.-� g� .�'��_ �. . �� . � l . - �.-�/ .:,_-s.; r. �` - W� 's'C� rr ->�t"� �- .. - �. �'i"a yX�,, '�r. � , . _ ' ��:-.,. :�., ,3. '..'6 +Y�'��t� �i.' i� .. ;..V 4 .G .��4-E . ' j 0 �� `� �•�'� _�.i �� •� ,� g-�>� ..� : . � , �. X � � MILE . , . � _ { . .. � � .� - , , _. ,, � X , : . _ s�. -:, �c �_. , �.- . - ' DOWNSTREAM � � � � . , �,,,�� ..-�� _ . _ � = �. � ,' _ -'',� ;�. �y � I x `" ' . '_ _ � s r.'"�' 4 _ _' _ �� +�' 'w • � 'i . . _ � � � �� ,�. ' ' --'. ' �^_• `+i. ` . y, -:.. ._ -� .. 1'° L " . • - E rc. L'� ' �• _ _ -'. w �i •, f " .a �' - ... i " . . � � � " _ �. �, � �t �„� � PANTHER CREEK : , ' }� .�y� ,. ,,�1,. � ,;�� :�.�. N y t C ~ _ ` ' •a i. .• �9 _ ,iP . , � � �. �; TRIBUTARY �� .- �"� -� �. ';�:�2 � :{ ! , . . : . � _ . . , , ,, x �. .� , � � �. i � ' .` ;iy -_ � Y �i � ' x�. .� ��-� . - . . •��,� - ' - X ° �'� ` ��- . �li � Q] .� L. �.: . '` , " . +'. �� J a �.. . , s }� . � . � / .. . . �.�:....:� C„ . �i` ;_- Y ',_ -- - . .y` r ' "....�� . S�!'�l�.� _ -j' . h ' t�f.S ' ..� - �. _ ,,y,,�} ` {�' �L `s '`�'� � :, _ r : , >. w � •. �. . . • r ��. 'i:�.:..,:.,1�/.-.- � -��.-�.,�r-. �_. ..�r �.. --t.lt.�.� t.._ , ...� +ir �.. �..�.]➢�%t�``:.r�+il� . 7� �"�i-��'� _., : . . . ... �.. � � �v�: '�= -�'S :r.._'i��='Y�.. .l�E��-: _� U = � ,.. . . �7 . . . � � � � DOWNSTREAM FLOWPATH � � Q � DRAWN BY DESIGNED BY � 0 50 �oo X �� CB CB � , o ' CHECKED BY APPROVED BY z 'i � > AGC AGC ' ^ = DATE , KING COUNTY HOUSING AUTHORITY SHEET N o o� 16 2014 160J Fifth A►�enue, Suife91600ne� NOT UPDATED VANTAGE POINT APARTMENTS — �'� � � � J 0 B No. :113188 S „C A L E: s�tae, ��,��gr«► 9a�o�-sss,s , � � � _ � oo r2�� 622-�22 Fox <2�> 622-8�� FOR ASBUILT FIGURE 5. OFFSITE ANALYSIS , � x OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT#Z Basin: GREEN RIVER Subbasin Name: PANTHER CREEK Subbasin Number: Symbol Drainage Drainage Slope Distance Existing Potential Observations of field Component Type, Component from site Problems Problems inspector, resource Name, and Size Descri tion dischar e reviewer, or resident see map Type:sheet flow,swale, drainage basin,vegetation, % '/.ml= 1,320 ft. constrictions,under capacity,ponding, tributary area,likelihood of problem, Figu re 5 stream,channel,pipe, cover,depth,type of sensitive overtopping,flooding,habitat or organism overflow pathways,potential impacts pond;Size:diameter, area,volume destruction,scouring,bank sloughing, surface area sedimentation,incision,other erosion • CB 38 Type 2 48" Sitedischarge point 0 FT NONE NONE No evidence of overtopping 12" CPEP 1.00% NONE NONE • CB 40 Type 2 48" Connection to EX 12��cnnP 38 FT NONE NONE No evidence of overtopping 12" CMP 3.92% NONE NONE Joins runoff from Westview Village • CB 8137 Type 1 a,pc5,structure rim in gutter 161 FT NONE NONE No evidence of overtopping 12" CMP unavai�b�e NONE NONE • MH 8178 �ains runofffrom Fred Meyer, 223 FT NONE NONE No evidence of overto in structure rim in slope PP g 36" CMP unavai�ble NONE NONE �� loins runoff from Spring Glen Day • CB A Type 2 72 Care,structure rim in sidewalk 622 FT NONE NONE No evidence of overtopping 36" CMP unavai�b�e NONE NONE • MH B �oins runofffrom Fred Meyer, 680 FT NONE NONE No evidence of overto Ifl structure rim in slope PP g 36" CMP unavai�b�e NONE NONE • CB C Unabletolocate 750 FT NONE NONE No evidence of overtopping 36" CMP Unavailble NONE NONE • CB D T e 2 54" Rimadjacenttosidewalkin g24 FT NONE NONE No evidence of overto in YP landscaped area PP g NOT UPDATED FOR ASBUILT ,�9,zoo9 OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE SURFACE WATER DESIGN MANUAL, CORE REQUIREMENT#2 Basin: GREEN RIVER Subbasin Name: PANTHER CREEK Subbasin Number: ------ --- - _. ._ ___ ._ Symbol Drainage Drainage Slope Distance Existing Potential Observations of field Component Type, Component from site Problems Problems inspector, resource Name, and Size Descri tion dischar e reviewer, or resident see map Type:sheet flow,swale, drainage basin,vegetation, % '/.ml=1,320 ft. constrictions,under capacity,ponding, tributary area,likelihood of problem, stream,channel,pipe, cover,depth,type of sensitive overtopping,flooding,habitat or organism overflow pathways,potential impacts pond;Size:diameter, area,volume destruction,scouring,bank sloughing, surface area sedimentation,incision,other erosion 36" CMP Unavailble NONE NONE � CB E loins runoff from SE Carr Rd system, gg1 FT NONE NONE No evidence of overto In rim in KFC parking lot PP g 36" CMP Unavailble NONE NONE • CB F T e 2 �oins runofffrom KFC,rim in KFC 984 FT NONE NONE No evidence of overtopping yp parking lot 60" CMP unavai�b�e NONE NONE • CB G Vault Large vault with rim and lid above surroundinggradeinravine 1198 FT NONE NONE No evidence ofovertopping 60" CMP unavai�b�e NONE NONE Open Channel NONE NONE No evidence of erosion NOT UPDATED FOR ASBUILT 1/9/2009 Chris Borzio From: Gary Fink[GFink�a Rentonwa.gov] Sent: Wednesday, December 11, 2013 6:57 AM To: Chris Borzio Subject: RE: Down Stream Drainage History- 17901 105th PI SE, Renton Thanks Chris, I'm familiar with the crossing at 105`h. We have no reported drainage issues along this path within the% mile range. Best Regards, Gary Fink City ot Renton Ufility Systems Division-Surface Water Utility Phone:(425)430-7392/Fax:(425)430-7241 GFinkCa�RentonWa.qov � cicy nE --��+�� #....e�,:a� f� From: Chris Borzio [mailto:Chris.BorzioC�kpff.com] Sent: Tuesday, December 10, 2013 5:02 PM To: Gary Fink Cc: Alberto Cisneros Subject: RE: Down Stream Drainage History - 17901 105th PI SE, Renton Gary, That culvert you mentioned is actually on a different leg of the creek than the flowpath from my site. My site's flowpath - crosses Carr just west of 105`h PI SE. The outfall structure was a large square precast vault with a 36" CMP pipe outfall to the creek. , Thank you, Christopher Borzio, PE, LEED Green Associate Civil Engineer ' KPFF Co^5ulti^y Eng:neers O: �206) 6�2-5822 D:�206j 426-041� � � 1601 Fif+h Avenue, Suite 1600 F: {206) 5�2-8130 5eatt'e b+lashington 48101 chris.borzio(a�koff.com www.koff.com ' `�Please consider the environment before printing this message. From: Chris Borzio Sent: Tuesday, December 10, 2013 2:04 PM To: 'Gary Fink' Cc: Alberto Cisneros Subject: RE: Down Stream Drainage History - 17901 105th PI SE, Renton , Gary, The Carr Road crossing is actually just at the end of my% mile review. Is it safe to say that the 2008 work has taken care of the flooding problem? I hiked down the embankment to the outlet of that culvert, see attached photo, it seemed to be in good shape. The creek bottom was cobbles without side soughing as far as I could tell. 1 Thank you, Christopher Borzio, PE, LEED Green Associate Civil Engineer KPFF Consulting Enginee�s O: (206j 622-5822 D:;2061 y2b-0418 1601 Fifth Avenue, Suite 1600 F: (206) 622-8130 Seattle Washington 98101 chris.borzio(o�koff.com www.kpff.com `�Please consider the environment before printing this message. From: Gary Fink [mailto:GFinkCa�Rentonwa.govl Sent: Tuesday, December 10, 2013 1:51 PM To: Chris Borzio Subject: Down Stream Drainage History - 17901 105th PI SE, Renton Good Afternoon Chris, Sorry to run a bit late on this information. Review of downstream drainage for the property located at 17901 105th PI SE did not identify any significant drainage issues. Just beyond the %-mile review area, we had localized flooding at the Panther creek crossing of Carr Rd. The culvert at this location was replaced in late 2008. Let me know if you need further information. Best Regards, Gary Fink City of Renton Utility Systems Division-Surface Water Utility ' Phone:(425)430-7392/Fax:(425)430-7241 GFink(a�RentonW a.qov City ot « r.�-� �� ----- f �� t' �f 1 ��,;;: _ �._: .. z � (� 40 -� I � PA 0.000 AC � IA 0.000 AC o, ' ' START BAqCWAiER ANALYSIS ' 3 .. N 4/ �-�_-� � / � `� Q Q , � � � i � PA 0.000 AC w F•': 1. IA 0.000 AC � 'sM; �, � I �� ascHnRc� PaNr � '�: � � � =- � `�� p ce �sos� � � � PA 0.053 AC 4J s► � IA 0.234 AC � � I .•. • :•: : � q�:;. ;.;: PERNOUS AREA c� ....... .. � � •..•.. .. � . / �� ,;: I _ _ � a. I - I �, � ��_� , Sl1BBASM1 AREA � `�; � � � �! b �; � ' � . < N � � � � _ � , .� a .µ � _ �.�. . _ � CB #7575 x �� ;' � PA 0.043 AC i ' � �'' IA 0.278 AC o j o � � ' � �, � � -, c� Q� . I �I Ro Plo+Y��K E�1s � ws'": � ■■ � 00�161 fffr•"OIC vM w C+_a . . -..._ j . �.... �.i RDPlW n.s�."� . "� CB #7076 Cg �723p � CB #7376 � : `� .zz . , � •� CB #1059 SUBBASIN € PA 0.069 AC ;PA 0.000 AC ,�_ PA 0.020 AC ' � PA 0.052 AC AREA _ �! IA 0.213 AC IA 0.086 AC IA 0.120 AC ` -- � _ � � ', �. — . _ �� -`- IA 0.244 AC �,E ` � _�. � i ti ; �. �. �� ..-�.°_ �-� ,� � �' ��y L(' . ` _ .._ _-_'_ - � � +�� i� �l�.r��...� '�n�l�� ' . . - �$�` �� . �' � �� .� �� :.,. .. -- --- . � -- -- -� � . � .. . . .._�. . �- - -` -- _ �,�_- � . . :_,.: _ . -,. ;., ...__ _ � • � � �.- -� - -, . . _ _�"-_. _ � p,w _. . 4- `¢ � , _,� _ „ , �- �_6 . _-'. .+- '� ,� . _. I - _._.�_�_— 1V _, • __ ... / , ,_--_ �--�� i- � 3M \ -! � _ ( � ` � � .... _ �' ...:. �_ � _ ` . .. . � . . r -., / _.— _.. �� - � �.+N` � \ � `__'—._ --- � G� . �� .. .. ...-____�_ _. . .. .. ` . -... �, Q � ` \` � ... ' ' . . .' ._ F_ . -.= n. _ '.�'3^Y}+� _..._ . __. ..��. �.^.._ —._ - ---`,. ._ .-.. .. .__ �. . . ♦ � � ` \ ._.:. 1 �� .. - .'', � � ` . �- - ' .. . .� . .. /� � \ .. F t .. .... .�.. .... _. . � � :•� ��.. �! I X� � � —__'�� 'Y�� w�_—=� � �` .tY.�.`�.�_ — r� Q . • s�.. �..:�' ae+a� .a,_ "�"��,,.: .i. . . � ."� b' : �1 1 � :.�—•�ww��wr r� r --_�' '� t� ` ....� s .�, I c' �--��rr�f . . �� „� �� .. � . � ��i� � ti + X NORTH � ' m �„ � Q L w U � Q / d (!� > DRAWN BY DESIGNED BY " CB CB o 3o so � � � CHECKED BY APPROVED BY � > AGC AGC ; — DATE , KING COUNTY HOUSING AUTHORITY SHEET o � 7 16 2014 1601 Fifth Av�nuenSulite91600ne� NOT UPDATED VANTAGE POINT APARTMENTS N ° S C A L E: Seattle, Woshington 98101-3665 � � � o B No. :113188 �� _ � F I G U R E 6. U P S T R E A M A N A LY S I S _ � 1 6 0 (zas) sz2-58zz FaX (zos) s22—a�,3o F O R A S B U I L T � X k ff Appendix B Drainage Facility Documentation and Design Vantage Point Apartments Technical Information Report Appendix B KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL STORMWATER FACILITY SUMMARY SHEET DDES Permit Number TBD (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Overview: Project Name VANTAGE POINTAPARTMENTS Date ��y��1/8/2016 Downstream Drainage Basins Major Basin Name GREEN RIVER Immediate Basin Name PANTHER CREEK Flow Control: Flow Control Facility NamelNumber DETENTION POND Facility Location 17901 105th Place SE, Renton, Washington 98055 If none, Flow control provided in regionaUshared facility (give location) No flow control required Exemption number General Facility Information: Type/Number of detention facilities: Type/Number of infiltration facilities: 1 ponds ponds vaults tanks tanks trenches Control Structure Location Type of Control Structure FLOW RESTRICTING ORIFICE TEE Number of Orifices/Restrictions 2 Size of Orifice/Restriction: No. 1 1-1/16" No. 2 1-1/2" No. 3 No. 4 Flow Control Performance Standard LEVEL 2 (FORESTED CONDITION) ASBUILT 2009 Surface Water Design Manual 1/9;'2009 1 KING COUNTY, WASHINGTON, SliRFACE WATER DESIG'�1 VIANliAL Live Storage Volume �`-,'-'-^�? Depth —�f�- Volume Factor of Safery 1.0 26,500 CF 5.28 FT Number of Acres Served 3.32 AC Number of Lots 1 Dam Safety Regulations(Washington State Department of Ecology) Reservoir Volume above natural grade 0, POND CUT INTO EX GRADE Depth of Reservoir above natural grade 0 Facility Summary Sheet Sketch All detention, infiltration and water qualiry facilities must include a detailed sketch. (11"x 17" reduced size plan sheets may be used) .l ; ASBUILT 2009 Surface Water Design Manual 1/9,�2009 2 ' sa�x+po�s ' �e•rrrE z w/armc�c� TQ�378.02 ��, f7'ADS IE 37287(q/7-E) '� 12'ADS!E 377.80(M-5) � � Y�--�'rE---x--%—k—M-7F� X�� N I� ��(-_=1�'��3�� 6'LLFNC .y � I � —38� � � � �-.,�'� ' II �/ � / / J P1ll �� I / ��'/��----_3•''8----------------"___-�\'_' ^`�_',�T- _.�' � � �/� � _ -,..� _. '.,. I // / / /��—__--_ 76____ ---________�\ � \ II � : _.� _—_ T-'- �. / / --- ------------- I ,F � � � / �� 3�a----------- \ 1 ----------------- � SCAI_E:1'= 10' � � i � r r� �' ,,-----3�z---------------------- •� ��il� i �I ' � � I � � � i �� ! II I sam/�osa o s �o m � � 1 II � +e•�z 1- I1� � ( � � f I 'T .S�- 1 • �L5 17'ADS lE J72.38(CU a N) I �` I I I � � � � �'EB 12'ADS lf 372.39(!N-5) I � � � 1 � �� 2-ws ie 3�s.�e(�-w) I I l l � 1 �� I 1 1 l 1 1 � rz'�os I � � � ` 1 ` 1 1 � ` W/TRASN RAL7( I � S1'MBOL LEGEND HA7CH L£GENO p 1 " � � lE 37269 � p� � � � —7�--X—FENCE L1NE �. � 1 I ` 1 I iOP 7RASH RApC EIEV.37&OT , ..:./ " I � ❑ CB CATp1 BASM'C Tl'P 1) � GRAbFL m�1 1� 1 ,� 1� `� 1\ _ z7Y.�� 1 � so,vH smav orrnau wero+a.F(rn x) 11 1 1 1 1 � / _ I I j o snco s�acx�oaAa ctE�Hour � �1 1 1 1 1 � � 1 . I I � � m r.wo ar�w cavarE� �� 1 \ 1 �� ! : 1 f � o ssco sn,v��.wr se�cte�weur � �rciwo "� 11 1 1` 1` \ \ � � �� O ss�m sn,wr,�ar sc�wn�atr ` ,1 1 1 \ \ �\ �\ I ._-_. �� f i �P PIV PQSI MpCA7IM VALYf � ASPNALT PAVEMENT ,�1 � ` � � �, \ � �' 3<°��- � I - m so�wPo�2 oa �cv rcmrcnnori cavma vu� � cx�snNc su��aNc \ � \ , w, ocm+nav I � ! � PA � +e'�rre z � xu w��rr u��tx \� �\ ` � a. \ � aavo � � � I U J2'AOS f£37.1Os(OUT-N) � wv wA�x v�i�€ � a \ \ � AVE POND BOTTOM=37i.13 I � � �.. �_ f2'ADS 1£J7285(M-W) � WIM� wA7ER MANHOLE wn c \ \i„ o � � � \ � I '� 1 I � � TOP 12"Rl9?R E1EV.3759�CORRECTED TC m � � 1 1 \ � 1 � � �� 1 ( � �. 6"ELBOW lF J7S57 377.00 F1EiD/.DJUS'MEf:T � £.B £(ECIRICA(,NNC7/0N BOX \ '1 \ \ � + � I . 1 I .'.I W/Ijj'ORIFICE LS LIGHT 57ANOARD(PARK/NG LGTj , ` � \ \ 1` \\ � I � � . '.I � � o�iv��i�a��owiv eorra,u �-� s srneer ucHr ��, ` �1 ` �` , � I � �. . I � � a�rr�sae,vor aer�,v�n 1` 1 \ \ \\ \1 I � ��z o _ � A � u rFanRE� \, � \ � � � \ � � EXT.CURB EXTRUD£O CURB � ti � \ \ � � I � � v�a�euRe �xnc�i Aae� \ � 1 �1 � �� 1� �` � I � � � c�Fr�c ctiAih unH�Ncc � 1 � \ \ � 1� � j I � \, \ \ \ \, ` � � i : !1 i `, `� \ \\ 1\ \ \� � � I ''� / \ � \ \ 1 � J � \ \ \ 1 `\ 1� rz �os � � � i��$ ` � � � \ \ � � \ W/TRASN RApC � � -� ��.'� � \ � 1 � \ I£J7S 9H I � � l.i� t \ \ \ � � I t �. �J I � � � � �� i � j � �� N ti � � � � � � W�� i � i � � � � W \ �� \ �� \��W/iRASH RApC ; � � � r a� � � \ \ \ \ � �376.J5 � � - \ � � � � V � �\ \ \\ \\ �\\ �\ ; I i I / 2 m c% \ �\ �\ �� \ :r�2,\ �/.., � � i -.��" P� .�. i� 1(�a cs m. � � � � �\ � � �'.`.� �.. \ \ � �� _ ,� \ ../ _ � \� \ \� 4 _/ �/ //.�.� �� \\\ �� \�\ \�376 �i�� \ // 1 PA � 'h \ � �� '�.� ...�� " . \\ ��\\\�\ �372 �(_[._��'��'(��J. �, �, �,, ��8�� , _ ,�',�� ; ' ASBUILT POND �' ��--" �`;� �x�'��` �I FACILITY SKETCH �s �X�x� �� / �\� � �I '�� ORIGINAL FIGURE DATED 11/20/2015 �� '��\ PROVIDED BY TRIAD ' `�T (MODIFIED BY KPFF FOR MODELING � c� `�� ,��, CALCULATIONS) �� ti� � �� _ �� `` I cgpos, \� I r�se�.oe �� 9GN 1212A L75 lE 376.JB(1N-S) �11� � � .. -.. .. _. \� `1 - 1, I '�x 1\1 � soco� 1 saea o 1 1 .. /�♦' - yD� '.. . �. 1\ � .. � � ' , .. .- . ... � . : .. . :�. �.:.� SOLU : � ..�.. . .. Pa .� ,. � � LS ' � �..��. . ,_ ._. � . ....� -.. ..._ � 1 II I . ... I LAD�ER— • `�0 i RWND FRAAIE AND ABOVES � � . \\ i� SOL1D COVER I'� ti i Ri� �a.&}379.65 ��„ SECONDARY INLET , ,. , - �O • 54" TYPE 2 WS ELEV. p � � ' CATCH BASIN 377.00 � � 12'PoSER a\� /� 6' ELBOW , DEBRIS BARPoER� \ ' v"�i. 1 1/2°! N ORIFlCE , �1F 2X � POND BOTTOAI ELEV. - �se 371.13 � /�i 12" IE 37285 N= �2'iE 3�373.04 �` �i2' iE 3�3ee 37269, � �'�6' SEDIMENT STORAGE ' [V� I� � �/�6�4 , - ORIFICE CONTROL STRUCTURE CUSTOM e SCALE: 1' = 2' - ASBUILT Cover Type BMP's POSTDEV DET Time Series WSEL Time Series o Till Grass0.8739�9�AC Pervious Pavmt(50%imp 50%grass) 0.136 AC Till Grass 1.11 i-9}�AC Impervious 0.20 9.i'}}AC w Z Total 3.019�955 AC Grasscrete(All Grass) 0.172 AC Impervious 1.710 AC � WSEL 0.19663}}AC Total 2.82 �?ri4�AC � v ?� m � � D Z 3 � �Q N O W .� � N C Ill r^ y T oo C � � � � � � � � m O r*+ � m z a 3 v n0 '^ � v_+ � z '�^., I � � m � m � � D m D n m � � � ? n � II C) rn � � w � ��i+ v� Q � � � � � U Z r � � � � , m 0 z m r C m D � rn D � D � C ' r ' D � O z -� D � r rn X:\113001 173250\113188(Vantage Glen�\PROIECT DOCUMFNTS\Storm Drainage\Detention&Conveyance Calculations\KCRTS\Cover Types.xls INPUTS.exc KCRTS Program. . . File Directory: C:\KC_SWDM\KCRTS\ [C] CREATE a new Time Series ST 3.20 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0.00 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 outwash Pasture 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 wetland 0.00 0.00 0.000000 Impervious PREDEV.tSf T 1.00000 T [C] CREATE a new Time Series ST 0.00 0.00 0.000000 rill Forest 0.00 0.00 0.000000 Till Pasture 3.20 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 outwash Pasture 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 wetland 0.00 0.00 0.000000 Impervious EXISTING_GRASS.tsf T 1.00000 T [C] CREATE a new Time Series ST 0.00 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 1.11 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 Outwash Pasture 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 wetland 1.71 0.00 0.000000 Impervious POSTDEV_DET.tsf T 1.00000 T [C] CREATE a new Time Series ST 0.00 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0.00 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 outwash Pasture 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 wetland 0.20 0.00 0.000000 rmpervious POND_WSEL.tSf T 1.00000 T [C] CREATE a new Time Series ST 0.00 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0.21 0.00 0.000000 Till Grass Page 1 ASBUILT INPUTS.exc 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 outwash Pasture 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 wetland 0.15 0.00 0.000000 impervious POSTDEV_BYP.tSf T 1.00000 T [C] CREATE a new Time Series ST 0.00 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 1.11 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 outwash Pasture 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 wetland 1.71 0.00 0.000000 Impervious POSTDEV_DET_15MIN.tsf T 1.00000 F [C] CREATE a new Time Series ST 0.00 0.00 0.000000 Till Forest 0.00 0.00 0.000000 Till Pasture 0.00 0.00 0.000000 Till Grass 0.00 0.00 0.000000 Outwash Forest 0.00 0.00 0.000000 outwash Pasture 0.00 0.00 0.000000 Outwash Grass 0.00 0.00 0.000000 wetland 0.20 0.00 0.000000 Impervious POND_WSEL_15MIN.tsf T 1.00000 F [T] Enter the analysis Too�s Module [P] Compute PEAKS and Flow Frequencies PREDEV.tSf PREDEV.pkS [D] Compute Flow DURATION and Exceedence predev.tsf PREDEV.dur F F 14 0.149615E-01 0.445000E-01 [P] Compute PEAKS and Flow Frequencies EXISTING_GRASS.tsf EXISTING_GRASS.pks [P] Compute PEAKS and Flow Frequencies POSTDEV_DET_15MIN.tsf POSTDEV_DET_15MIN.pks [R] RETURN to Previous Menu [A] ADD Time series POND INFLOW.tsf 2 POND_WSEL.tsf 1.00000 0.00000 POSTDEV_DET.tsf 1.00000 0.00000 Page 2 ASBUILT INPUTS.exc [A] ADD Time Series POND INFLOW_15MIN.tSf 2 POND_WSEL_15MIN.tSf 1.00000 0.00000 POSTDEV_DET_15MIN.tSf 1.00000 0.00000 [A] ADD Time Series CONSTRUCTIQN.tsf ` �� POND INFLOW?t5f E��'J �� i.o0000 0.o0000 �Y;��. ' t��T POSTDEV_BYP.tsf ,/� 1.00000 0.00000 � [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies �_ � POND INFLOW.tsf * ';(�� ' POND INFLOW.pkS ' [P] Compute PEAKS and Flow Frequencies ��F�� POND INFLOW_15MIN.tSf ,� POND INFLOW_15MIN.pkS [P] Compute PEAKS and Flow Frequencies CONSTRUCTION.tSf CONSTRUCTION.pkS ' [R] RETURN to Previous Menu [S] Route through a SINGLE (1) outlet Reservoir •°�� 05�� - CHECK POND.R51 � �N�? �5�'� 3 pond inflow.tsf - < CHECK POND OUT.tSf • - f [A] ADD Time Series � CHECK POC.tsf ,�,�-�--�,•�% 2 �.�� CHECK POND OUT.tSf i.00000 o.00000 �� POSTDEV_BYP.tSf 1.00000 0.00000 - [T] Enter the Analysis TOOLS Module [P] Compute PEAKS and Flow Frequencies CHECK POC.tSf �- CHECK POC.pks ,�%�V�' ` `'"��; "`� [P] Compute PEAKS and Flow Frequencies 5 � CHECK POND OUT.tSf '�� CHECK POND.pkS ,� , [C] COMPARE Flow Durations predev.tsf ; �__, check poc.tsf ' DURATION.PRN j `�'t'�-UL' F 0.445000E-01 0.202 14 [R] RETURN to Previous Menu Page 3 ASBUILT PREDEV.pkS Flow Frequency Analysis Time series File:predev.tsf Project Location:5ea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (�FS) (CFS) Period 0.202 2 2/09/Ol 18:00 0.258 1 100.00 0.990 0.055 7 1/06/02 3:00 0.202 2 25.00 0.960 0.150 4 2/28/03 3:00 0.155 3 10.00 0.900 0.005 8 3/24/04 20:00 0.150 4 5.00 0.800 a.089 6 1/05/05 8:00 0.131 5 3.00 0.667 0.155 3 1/18/06 21:00 0.089 6 2.00 0. 500 0.131 5 11/24/06 4:Q0 0.055 7 1.30 0.231 0.258 1 1/09/08 9:00 0.005 8 1.10 0.091 , Computed Peaks 0.239 50.00 0.980 I NOT UPDATED FOR ASBUILT Page 1 ,-- ' 'y ' POND INFLOW.pkS Flow Frequency Analysis Time Series File:pond inflow.tsf ; Project Location:5ea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency ,4nalysis------- Flow rtate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period _ 0. 562 6 2/09/Ol 2:00 1.14 1 100.00 0.990 0.459 8 1/05/02 16:00 0.722 2 25.00 0.960 0.676 3 2/27/03 7:00 0.676 3 10.00 0.900 0.497 7 8/26/04 2:00 0.597 4 5.00 0.800 , 0. 597 4 10/28/04 16:00 0.597 5 3.00 0.667 0. 597 5 1/18/06 16:00 0. 562 6 2.00 0.500 0.722 2 10/26/06 0:00 0.497 7 1.30 0.231 ' 1.14 1 1/09/08 6:00 0.459 8 1.10 0.091 Computed Peaks 0.998 50.00 0.980 Page 1 Flow I Invert out= 373.04 FT Detention Live Storage= 3.96o FT Diameter of orifice 1= 1.063 IN Q� Full Discharge= 0.061 cfs STAGE, AREA, TOTAL VOL, AND Height of orifice 2= 2.530 FT QT ARE USED IN CHECK Diameter of orifice 2= 1.500 IN Q1 at Orifice 2 elev= 0.049 cfs POND.RS1 TO REPLICATE THIS c?z Full Discharge= 0.073 cfs ORIFICE CONFIGURATION Q T= 0.134 cfs Riser Top= 377.00 FT Riser Diameter= 12.00 IN CONTOUR Average ELEVATION STAGE AREA Area INC.VOL TOTALVOL Qr 4z QroP 4r (FT) (FT) (SF) �5F) (CF� (CF) (CFS) (CFS) (CFS) (CFSf TOP SED STORA6E 371.72 0.00 3,517 0 0 0 0.000 0.000 0.000 0.000 372 0.28 3,656 3,587 1,004 1,004 0.000 0.000 0.000 0.000 373 1.28 4,179 3,918 3,918 4,922 0.000 0.000 0.000 0.000 � IE OUT 373.04 1.32 4,202 4,191 168 5,089 0.000 0.000 0.000 0.000 '� z 374 2.28 4,767 4,485 4,305 9,394 0.030 0.000 0.000 0.030 0 375 3.28 5,373 5,07a 5,070 14,464 0.043 0.000 0.000 0.043 376 4.28 6,011 5,692 5,692 20,156 0.053 0.040 0.000 0.093 376.92 5.20 6,658 6,335 5,828 25,984 0.060 0.071 0.000 0.131 RISER TOP 377 5.28 6,716 6,687 535 26,519 0.061 0.073 0.000 0.134 + � 378 6.28 7,486 7,1�1 7,101 33,620 0.068 0.095 10.590 10.754 � w 379 7.28 8,317 7,902 7,902 41,522 0.075 0.113 30.852 31.039 � 3 ASBUILT From 2009 King County Surface Water Design Manual Orifices Flow through onticc plates in thc standard icc xcnon or turn-do��n cl�xc ma� hc approsimatcd hc thc �eneral equati��n: L) = C9 2gh ��-a� �tih�rc �l — flow(cfsl C' = cocfticicnt ufdischargc(Q62 for piatc orificcl a = area of orifice{sn I h = hydraulic head Ift) I .�; — gravity i32-2 R�'scc ) I F7(:l'Rt:S.3.d.F: RF:('l'.�\ClJ1.:�K,tiN:1RP-('RF:ti'fEll N F:IR _ H � riser � D � P �--- PLAN VIEW NTS � SECTION NTS �� = ccl-�-zN►�r' �s-�r „�:�r� c� = n�W tersf C = 3.27�d.40 H-"P(ft1 1/,P arc as shown abo��c L = k'ngth(R)of the pomon oPthe nser circumference as neceasary not to eYcced 50°ro of the circumference I) - inside riser diameter(ftl \'.ue ri�u;tl�r.+eyr�ulie�n acruunt�)�,r sie/e.n�rn,�r�iuirs h� suhtruetrrtr;0 IH/rom L/ur ruch,rJe��+l�hr ne�leh i��e'tt-. \ � WEIR=FULL CIRCUMFERENCE; THEREFORE,NO SIDE CONSTRICTIONS Q=CxLxH3/z ASBUILT CHECK POND.RS1 One Outlet Reservoir Routing File stage Discharge Storage Perm-Area (Ft) (CFS) (Cu-Ft) (Sq-Ft) 0.00 0.000 0. 3517. 0.28 0.000 1004. 3656. 1.28 0.000 4922. 4179. 1. 32 0.000 5089. 4202. 2.28 0.030 9394. 4767. 3.28 0.043 14464. 5373. 4.28 0.093 20156. 6011. STAGE AND DISCHARGE 5.20 0.131 25984. 6658. FROM POND DISCHARGE 5.28 0.134 26519. 6716. TABLE 6.28 10.75 33620. 7486. 7.28 31.04 41522. 8317. 0.00 Ft : Base Reservoir Elevation 150.0 Minutes/Inch: ,4verage Perm-Rate = 0.40 IN/HR ASBUILT Page 1 CHECK POND.pkS Flow Frequency Analysis Time series File:check pond out.tsf Project Location:5ea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) (ft) Period 0.134 2 2/09/O1 20:00 0.631 5.33 1 100.00 0.990 0.032 7 12/28/O1 17:00 0.134 5.28 2 25.00 0.960 0.084 5 2/28/03 7:00 0.107 4.63 3 10.00 0.900 0.027 8 8/26/04 6:00 0.092 4.25 4 5.00 0.800 0.042 6 1/05/05 15:00 0.084 4.11 5 3.00 0.667 0.092 4 1/18/06 23:00 0.042 3.20 6 2.00 0. 500 0.107 3 11/24/06 8:00 0.032 2.41 7 1.30 0.231 0.631 1 1/09/08 10:00 0.027 2.18 8 1.10 0.091 Computed Peaks 0.465 5.31 50.00 0.980 ASBUILT Page 1 CHECK POC.pkS Flow Frequency Analysis Time Series File:check poc.tsf Project Location:5ea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.168 2 2/09/O1 18:00 0.672 1 100.00 0.990 0.047 8 12/28/O1 15:00 0.168 2 25.00 0.960 0.112 5 2/28/03 4:00 0.141 3 10.00 0.900 0.052 7 8/26/04 2:00 0.120 4 5.00 0.800 0.070 6 1/05/OS 8:00 0.112 5 3.00 0.667 0.120 4 1/18/06 21:00 0.070 6 2.00 0. 500 0.141 3 11/24/06 4:00 0.052 7 1.30 0.231 0.672 1 1/09/08 10:00 0.047 8 1.10 0.091 Computed Peaks 0.504 50.00 0.980 ,�-� � __� ' i _� 1 � j : i - ASBUILT Page 1 POND INFLOW_15MIN.pkS Flow Frequency Analysis Time series File:pond inflow_15min.tsf Project Location:5ea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) CFS Period 0.909 6 8/27/O1 18:00 2.81 1 100.00 0.990 0.648 8 1/05/02 15:00 2 25.00 0.960 1.96 2 12/08/02 17:15 1.27 3 10.00 0.900 0.732 7 8/23/04 14: 30 1.13 4 5.00 0.800 1.13 4 11/17/04 5:00 1.09 5 3.00 0.667 1.09 5 10/27/05 10:45 0.909 6 2.00 0. 500 1.27 3 10/25/06 22:45 0.732 7 1.30 0.231 2.81 1 1/09/08 6:30 0.648 8 1.10 0.091 Computed Peaks 2. 53 50.00 0.980 USED IN DOW NSTREAM CONVEYANCF CALCULATI� ��'� ASBUILT Page 1 CONSTRUCTION.pks Flow Frequency Analysis Time Series File:construction.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.614 6 Z/09/O1 2:00 1.24 1 100.00 0.990 0.499 8 1/05/02 16:00 0.784 2 25.00 0.960 0.737 3 2/27/03 7:00 0.737 3 10.00 0.900 0. 539 7 8/26/04 2:00 0.650 4 5.00 0.800 0.648 5 10/28/04 16:00 0.648 5 3.00 0.667 0.650 4 1/18/06 16:00 0.614 6 2.00 0. 500 0.784 2 10/26/06 0:00 0. 539 7 1.30 0.231 1.24 1 1/09/08 6:00 0.499 8 1.10 0.091 , Computed Peaks 1.09 50.00 0.980 II NOT UPDATED FOR ASBUILT Page 1 POSTDEV_DET_15MIN.pks Flow Frequency Analysis I Time Series File:postdev_det_15min.tsf � Project Location:Sea-Tac �, ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.815 6 8/27/O1 18:00 2. 54 1 100.00 0.990 0.581 8 1/05/02 15:00 1.77 2 25.00 0.960 1.77 2 12/08/OZ 17:15 1.14 3 10.00 0.900 0.656 7 8/23/04 14:30 1.02 4 5.00 0.800 1.02 4 11/17/04 5:00 0.979 5 3.00 0.667 0.979 5 10/27/05 10:45 0.815 6 2.00 0.500 1.14 3 10/25/06 22:45 0.656 7 1.30 0.231 2. 54 1 1/09/08 6:30 0. 581 8 1.10 0.091 Computed Peaks 2.28 50.00 0.980 NOT UPDATED FOR ASBUILT Page 1 EXISTING_GRASS.pks Flow Frequency Analysis Time Series File:existing_grass.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.286 4 2/09/Ol 2:00 0.676 1 100.00 0.990 0.146 7 1/05/02 16:00 0.363 2 25.00 0.960 0.363 2 2/27/03 7:00 0.293 3 10.00 0.900 0.060 8 8/26/04 2:00 0.286 4 5.00 0.800 0.158 6 1/05/05 8:00 0.263 5 3.00 0.667 0.293 3 1/18/06 16:00 0.158 6 2 .00 0. 500 0.263 5 11/24/06 3:00 0.146 7 1.30 0.231 0.676 1 1/09/08 6:00 0.060 8 1.10 0.091 Computed Peaks 0. 572 50.00 0.980 � _.; � s ' i ! _ , ' ; ' l _ i ��- I ,�__, ; ��-, � '�,_� ,-, ' � �,_� NOT UPDATED FOR ASBUILT Page 1 DURATION.PRN 08-Jan-2016 11:27 Paqe 1(1) Duration Comparison Anaylsis Base File: predev.tsf New File: check poc.tsf Cutoff Units: Discharge in CFS LESS THAN -----Fraction of Time----- ---------Check of Tolera�ce------- ZERO Cutoff Base New %Change Probability Base New %Change� 0.�99 � 0.95E-02 0.67E-02 -29.2 I 0 .95E-02 0.094 0 . 039 -11. 9 0.056 I 0. 63E-02 �.37E-02 -42.1 � 0. 63E-02 0 .056 0 . 046 -19.1 � 0 .069 I 0.49E-02 0.27E-02 -45.8 I 0.49E-02 0 .069 0 .051 -26. 1 � 0.081 I 0.37E-02 0.20E-02 -45.8 I 0.37E-02 0.081 0.056 -30.2 r^ 0.093 I 0.28E-02 0.14E-02 -49.4 I 0.28E-02 0.093 0.065 -29. 6 D cDi� 0.105 I 0•22E-02 O.10E-02 -53.7 I 0.22E-02 0.105 0.076 -27. 9 C O 0.117 � 0.15E-�2 0.60E-�3 -58.9 I 0.15E-02 0.117 0.091 -21.9 0.129 � O.10E-02 0.36E-03 -69 .5 � O.10E-02 0.129 O. i06 -17.8 N m �.191 � 0.62E-03 0.18E-03 -71 .1 � 0. 62E-03 �.191 0.116 -17.6 � _ D.153 � 0.34E-03 0.11E-03 -66.7 I 0.39E-03 0.153 0.130 -15.1 � � 0.165 � �.21E-03 0.16E-04 -92.3 I 0.21E-03 0.165 0.139 -16.2 T - 0.178 � 0.16E-03 O.00E+00 -100.0 I 0.16E-03 0.178 0. 145 -18. 6 O 0.190 I 0.98E-04 O.00E+00 -100.� I 0.98E-04 0.190 0 . 155 -18.2 T There is no positive excursion LESS TH AN Maximum negative excursion = 0.027 cfs (-3�.7%)�1��o occurring at 0.089 cfs on the Base Data:predev.tsf and at 0.061 cfs on the New Data:check poc.tsf I � ASBUILT KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL Water QuaGty: RAIN GARDEN - 1 Type/Number of water quality facilitiesBMPs: biofiltration swale sand filter (basic or large) (regular/wetl or continuous inflow) sand filter, linear(basic or large) combined detention/wetpond sand filter vault(basic or large) (wetpond portion basic or large) sand bed depth (inches) combined detention/wetvault stormwater wetland filter strip storm filter flow dispersion wetpond(basic or large) farm management plan wetvault landscape management plan Is facility Lined? oiUwater separator If so, what marker is used above X RAIN GARDEN (baffle or coalescing plate) Liner? catch basin inserts: Manufacturer pre-settling pond pre-settling structure: Manufacturer high flow bypass structure (e.g., flow-splitter catch basin) source controls Design Information Water Quality design flow Water Quality treated volume(RAIN GARDEN) 238.726 AGFT I Water Quality storage volume (wetpool) Facility Summary Sheet Sketch NOT UPDATED FOR ASBUILT 2009 Surface Water Design Manual 1/9i2009 3 TYPE 2 CB - 8D1 1/4 SECTION NW 32 TOWNSHIP 23 RANGE OS STORM DRAINAGE NOTES: �` STA 21+36.26, 55.47 RT. IYPE 1 CB - 900 a_ ,�� ,1,ff_ `._t�`i,;i��\ ��'_ - oat __ RIU 382.42 1� � STA 21+37.44, 44.94 RT. 6' IE 380.40 1. HORIZONTAL CONIROL FOR STRUCiURES 3. STORM DRAIN PIPE CROSSING UNDER THE o � ' ' � fr-dc B" IE 7G.47 �W� } � RIM 339:59 379.95 6'PERF PVC PIPE ADJACENT TO CURB IS PROVIDED BY BUILDING SHALL BE iNSTALLID hIROUGH � 12'IE 33fr39 37 .4 (N� Ol1T � ti 12' iE 3��375.50 { T 0�.Ox STATION ONLY. CONIRACTOR SHALL lAY AN 18'DUCTILE NtON SLEEVE IXIQIDING m i 1Z" IE 376.�IK �` � fr-S�� IE 37&+4376.�U�N�Nd WT WRB L1NE TO DE7ERMINE D(ACT MINIYUAI 5'OUi510E THE FOOIING � �e ` � OFFSET NECESSARY FOR OUTSIDE OF SUPPORT. COORDINAh INSTAILAiION OF °i�'o � c o�-� . FRNIE TD AUGN WIiH FACE OF CURB. hIE SLEEVE W1TH STRUCIURE PLANS FOR �" `� i o � ' RAIN GARDEN - 2 RAIH GARDEN - 1 HORIZONTAL CON1F20L FOR STRUCTURES POiENiIAL AIODIFlCATIOH OF THE .c��`r.. 7YPE 1 CB- 8D2 UPPER WSEL 379.69� NOT ADJACENT TO CURB REFERS TO S1f2UC1URAl F0071NG. '" °p k UPPER WSEL 381.40 � �?o, o S T A 2 0+5 9J 3, 4 1.2 9 R T. p 7 T p A I E L E y 3 7 8.6 9 -- - y �� RMI 3B�8S 381.08 �TTOA1 ELEV 380.40 C E N i E R O F S 7 R U C I U R E. 13 LF 1Y HDPE SD 0 D.6x EWIRED BOTTOM AREA 67 SF REQINRED BOTTOAI AREA 1,141 SF 4. ALL PIPE OUTFALLS SHALL INCLUDE DEBRI � �� i2' iE 3�es 37 N) OUT � aN � 12' IE 376.38 �S�I � P�F PVC PIPE @ O.OX � �-^°"�*--�#F-� i 2. iRENCH DRAIN RIIA EIEVAiIONS SHOWN BARRIERS AND 4"-6' WARRY SPALL �.E o� � - + �_ - _+ '� ��p REFER TO CENiER OF TRENCH DRAIN WiFALL PROiEC110N, YINIMU61 2' 1MDE BY Q o"i� SEE SHEET C10.2 FOR 19 � FLOW CONTROI STRUCiURE B pp+pp t -�- - - 11 A � CATCH BASIN. REFER TO GRAqNG PLAN 4' LONG OR TO TOE OF SLOPE WHICHEVER �3`� W ADDITIONAL STORN DRAIN %� r 1 z--�6 6 C 6.3 1 R E N C M D R A I N - 1 0 0 0 ' � � - i i v Q MFORAIAl10N �'iE �s4 3 7 8.79 Z�+00 �'1 �. A DRA� � ,r. �i A N D A L I G N A I E N T P R O Fl L E S F O R R E A I A I N I N G I S G R E A I E R. ' `� Z �/' 1 2' I E 3 7 3.0 4 N O U T R i u �-s s i , , cs.a Ri►��ai.ss i ' r i R E N q i G R A T E E L E V A i I O N S � � ' iN �s" �E ��a 3�s.22 (s) ou � 10 TH PLACE SE ' ' - 6� ' � 5 ��N � z � � DElENT10N POND SHALL BE CONSTRUCTED ' "'- �379J4 S `- G t . • ` � / /; A S SHOWN HEREON AND IN ACCORDANCE . . „ , . . . �' � � .� • �r - �� WIiH SECTION 5.3.1.1 'DESIGN CRIlERIA" , ,y . , 0 5' DR_AIN_AGE SEIBACK v ' ' . ' • a '3 � a - - - - �- �_ ' ��, / THE 2009 KING COUNTY SURFACE WATER - - - - ' � . :.::f:`�.;�e°:°:::. .. .:.. .. .. .. � , .. ._ . .. - - - - -- , - - COTG � , ' • . . � � � �. ' � � �'9f DESIGN IIANUAL. , y / �� p G. CI � I �� T��``:'��'��°'� LG�� - ;�' 45 �� .77;r ---} �;I 0�59lF DI SD _ � y •,,\ //�, �� 6 SEPARAiION BETWEEN U�TY PIPES AT ��a��'�`��y � , ��° �,� °`°` `� c '::� , t _ I .. � � � �-� � ROSSI GS WHERE 12'IS NOT FEA518 � -� 6' CSBC OVER-� �i� - ,-��o��°��°�'o:'^o�a a< `'-� s � �� i 0 -i L =_ ; • �;' �'�G, � \ BETWEEN UTlll ES.OAA1 PAD AT CROSSIN @��,� � � ; � ._ �L ,� . _ � E �G . « CDAIPACIED SURBGRADE �� [�i'��,�`_ �r�i`:".`-�1.` . °� �� , u r-- - o ` -_�, � ti `rFF` ��o��,d I I `� �..'.�e`, �a�=� �` , ,°�� -__� - �� ° 7. ALL NEW STORM DRAIN SHALL BE NDEO I� � I I I � � � �� ,�� % ' � /�-�r,_ � 4'PVC DSP � , � 3�- �� 71+ ��12• IE 38�� , �'�� INSPECIED. VIDEOS SHALL BE SUBNITTED � �-- y' *_ � F �� I, � B LF 12'HDP 4",CO T '� �k9 LF�'r �� TO hIE CITY. � i �� iz'�5:�a I � �.i o�.oz�iN. � A ��-v� 380.26 l� � �P F � r��a C OVERFLOW STRUCIURE � ��I�I I ; J 8. IE'379.0' i _ i HD SD . � _�,�__-� C� �t�F��Pti a N�-H �-,r �ea � 375.98 �►'��sa o.s .� _- � �� .,_�.r � C6.3 BOTTOAI OF BIRDCAGE � ;t i � s'' � T . � I� ��I I IE 37269 �� „_ �� 378.9�-378.02 � 8.IE3�E59 % � 0 3flX 8 T 1 ,,, IE 378.37 18'DIP � � �� 2" iE 3�s2 372.8d '�I I I�I I `'��"' "" �" M SLEEVE , I S IN ��I'�l� UPPER WSEL 377 IE 376 35 �/ �,�°� (�) C6.4 E 376A ,� `-"--M�' , 8'PVC Iv � Q � ) I I I BOrrou oF UVE STatAc� EtFV. �371.72 � ' ` ,' -�-� 6' P4C POC FOR AIECH� 6 1.28x � � Q � I ' ��I�190TTOIA OF SEDIIIENT STORAGE EIEV. 3}?3 371.13�' // � I D� '/ 1 Z U � SUMP AND PIMAP � �'�I I �$��T STORAGE VOLUME?5,95f�6, � 4' P� IE 377.0 � , Z h I � TYPE 1 CB - 800 � � I I I � SEE NOiE 5/� �,- � � 0 1.Ox MIN. STA 21+99.20, 48.5�' RT �� wC = J g � i �' `� i iRENCH DR RqA 38�49 381.39 B' PVC DSP 1 G � I I � / -��; � � TYPE 1 CB - 100 [q � I ' I // � i . � STA �$'� IE 3�8 iS(SE) IN 378.39 0 1.28X RIM 384.$} .$�L o �0 20 �0 � Q � i , �_ 12'IE 3�9-}5(N) OUT 377.� 4' PVC DS POC 6' IE 3H0.94 N i �,cn=2o teet � � Z � � `,'� �_ ' � / - i 382_99 (W) OUT 8'PVC DOWNSPWT FOR YECH (TYP.) 12' IE ��EO.� IN � �� $ Q Z � �- � __ - T 8'PVC DONMSPOUT COLLECTOR (DSP) 0 , C AREA DRAIN � � �J� � � , -� IE 378.9 i COLLECTOR DSP 1.OS MIN. % (�)e lr IE 380.78 PlE � � / ��, � � F- � � � � � C6.4 CONNECT TO DSP 0 ', i� O � Q Z �C � 6' BLACK NNYL COATED CHAIN - / / 9 1.OX MIN. 2.OS MIN. SLOPE (TYP.) '� W Q W UNK FENCE PER WSDOT STD -- � / / ' - �1��.)eD AREA DFtAIN � jf, �. � Q 2� � DETAIL L-20.1U-02, TYPE 3, t/ �� _ � C6.4 RIU 38449 _� .�'�' Z W � Y W11H TOP RAIL � �i � _� 61}00 j � '� L �� 6' IE 381.99 (SE)OUT �6' 'x pR,k Cl) Z � . , � �� ' ' � - : iO O - - - � s�oo2 �= � V p a °� � 1 � - �,. . ... `, 1� I � � O T �I ' , _�� ' � O � Q �,, , ,. 42�00-- -- - - - IE 38�� _ � _ o� /'' �'� � � W ; �� 'Q �� ;, _ � �� --� � W , I ` ,. �� (') ' . �. � ,� -- �ti a > � , � � 0�O% se� � _ � � /I I �12�u'�? a�o n �� - - `� '� �'� ' TYPE 1 CB - 2 Q O e�� I � �/63±�/ -"' � ��'�4.t 43�00 _ rt-' �/^'', 0Z - - ST 44+88.42101 ~ o j Z � � 1 " � � _ � - -- -- „ , �i � / , � . I TYPE 1 CB - 105 .-= __�--+ • t� - / � ' �f 385.37 ` ., r � / �� STA 41+92.37 �2 lF 12"p� � - '� �`k "�6'PVC ppWN$ppUT B' IE :�•'�;"�, '��$1.37 (SE� Z � C � t2'IE 38�ee-381.37 (NN� IN / Q o cc o I � mM �e�383.97 �� CatECTort DSP o 12' IE 381.22 NE OUT � � �� .• �r�E �38252 (N,S) ( ) � ) � � � •, .-- " I '•, t.oX uIN. � i / � --�� 1 �6 Z� LF 12'DI SD '� • = I � � � 62}0� / - - \ , � TYPE 1 CB - 102 owi�nr,�ssu� 0 � ��`�.�' - TYPE i C8 - 104 \, I _ DESIGN DEV. N108113 � _ , ' i T Y P E 1 C B - 1 0 6 � � ,\ STA 44+06.03 � COORDINATION 01l15114 .� I � � Rni 4�e6 383.93 TAE43+8.86�� \ RIM�3g338�1 57 (NW� $E� IAND USE REYISION D6l09i4 $TA 41+68.58 / BID SET 05f15114 a Hnt 3e+.e�384.10 = 12' IE 38t#381.95 �N,S� RIN 383fiB 383.66 , 21 Lf DI SD � • IN � � � - - a' �aa3-s�-(E)n�38270 =;�= �2'iE�381.61 {N SE) o e-� . OX / a�n o o e►r o u r�e� o s r�u�a ' 'I - -- 12"IE 3B�3F(S)OUT�265 �- ' A2ADOENDUM Y4 07N7J14 � t, PRONDE 5' MqJ11AU1A � uiW7YSET 07n6n4 Y . Y"�'' ._ ' ., l � . `. .:. \``_. . \ CLEARANCE BETN�EEN � ��R��h�Y�R Ofl��91�4 I - � °F /. � -� ��y � { � ?� ` --- STORAI AND SANITARY / CONFORMCONSTSET 17/10/14 --�� ' y yf_ s?� J��'��`,��,- ,<�,Irtf_-_- SIRUCTURES(1YP.� �- = SURFACE 1REAilAENT PER � �"� ¢'� � �_� ��'\ - �� `_� ��`e"'� -- - , � � �ia,w � LANDSCAPE. SLOPE PER � , " �-, ` -= CITY OF RENTON , ,,,,o„�,�,�„ ,a,. �<";, � • GfiADING PLANS •: -- - -' � rdan�vma n.xa 4.5' S'AIIN. Approved bp: Date: � ��:� a,�N � -TYPE 1 CATCH BASIN � �- - - - - - - - - - c coFo�o�rser ,xuN 'c r� 12. _ - � ' � ; � �I �-�'- - Approved by: Date: • Call 811 u � 3 3 - ' � � �I o �1 --- �� 18' BIORETENTION SOIL � two bu�g eys befae d' � Approved by: Date: N'', 3 12� GRAVEL BAp(FlLL � ASNOTED W z -- FOR DRAINS �ra� �2��a�a 6'PERFORAiED UNDER DRAIN �P� IMV Approved by: Date: � 2-ROWS OF 1/2' DtA. HOLES, 120'� �a N� p� ' POND AND RAINGARDEN �' pN�Ery1ER. UCP U14001164 �R T� � AT ACCESS DPoVE HAVE 18' GRAVEL BACKFlLL FOR ..o. ��.. .o� n THIS SEPARATION DRAMS AT UNDERDRAIN ,s,o � AS NOTED �w� t► C�'y pF ' VANTAGE POINT APARTMENTS ,2-,o-zo„ _ ' �� R��j�J ON SITE IMPROVEMENT PLANS � �I � RAIN GARDEN SECTION A t"° °�� o , �' e� � �� DANM planning/Buflding/Public Works o�Pc. DRAINAGE PLAN C6.o _ � � ' SCALE: 1� = 3� - N0. REVISION BY ' DATE APPR �"`"��' � I� �! AGC � 16� 61 WWHM2012 PROJECT REPORT Project Name: Rain �arde:-, Site Name: Site Address: City . Report Date: 7/15/2014 Gage : Seatac Data Start : 1948/10/�l Data End : 2009/09/30 Precip Scale: 1 .00 Version : 2013/C8/23 Low Flow Threshold for POC 1 : 5C Percent of tne 2 Year High Flow Threshold for POC 1: �0 year PREDEVELOPED LAND USE Name . _:�-. - Bypass: '.� GroundWater: tdc Pervious Land Use Acres C, Lawn, Flat .528 Pervious Total 0.528 Impervious Land Use Acres ROADS FLAT 1.172 Impervious Total 1.172 Basin Total 1.7 Element Flows To: Surface Interflow Groundwater MITIGATED LAND USE Name : RA=tiGARC_I� - 1 Bypass: �;� GroundWater: Nc NOT UPDATED FOR ASBUILT Pervious Land Use Acres C, Lawn, Flat .528 Pervious Total 0.528 Impervious Land Use Acres ROADS FLAT 1.172 Impervious Total 1.172 Basin Total 1.7 Element Flows To: Surface Interflow Groundwater Surface IN�ARDEN - � Surface INGARCEN - � Name : RAIN�ARDEN - � Bottom Length: s3 .?9 ft. Bottom Width: 33. 79 rt. Material thickness of first layer: _ .5 Material type for first layer: �NL'�Wtti Material thickness of second layer: C Material type for second layer: Sand Material thickness of third layer: 0 Material type for third layer: GRAVEL Underdrain used Underdrain Diameter (ft) : �� . 5 Orifice Diameter (in) : . Offset (in) : � Flow Through Underdrain (ac-ft) : �21 .196 Total Outflow (ac-ft) : :'�4.9 Percent Through Underdrain: 98.35 > 91% �/ Discharge Structure Riser Height: 1 f�. Riser Diameter: �4 i�. Orifice 1 Diameter: =� i... Elevation: � f= . Element Flows To: Outlet 1 Outlet 2 RAINGARDEN - 1 Hydraulic Table Staqe(ft) Area(ac) Volume(ac-ft) Discharge(cfs) Infilt(cfs) �� . 0000 C .0342 �.0000 O . 00OC C , _ � . )275 C.0341 �.Q�06 C . 00OC C .C: _� . J549 0.0339 0.0011 O .OGOl C . C' ='� . J824 0.0338 0.001� C.0001 C . C: -', . 1099 0.0336 O.OJ2 C. � C . C:: _ . , �-�� . ��;� r� . �-�_.� OT �J.f��TE C� cnn � �pi ��i � - I 0. "1648 0 . 0333 0.0034 0.0007 0 .0000 �.1923 0 . 0332 0.0040 0 .0010 0 . 0000 0.2198 0. 0330 0. 0096 0 . 0014 0 . 0000 0 .2473 0.0329 0. 0052 0 . 0018 0.0000 0 .2747 0.0327 0. 0058 0 . 0024 0.0000 C .3022 0.0326 0.0064 0. 0030 0.0000 C . 3297 0 .0324 0.0070 0.0037 0.0000 G,3571 0 . 0323 0.00`16 0.0045 0.0000 �.3846 0 . 0322 0 .0082 0.0054 0.0000 � . 4121 0.0320 0 .0088 0.0064 0.0000 0 .4396 0.0319 0 .0094 0 . 0075 0.0000 0 .4670 0.0317 0. 0101 0 . 0087 0.0000 0 . 4945 0.0316 0.0107 0.0101 0.0000 C . �220 0.0314 0.0113 0.0115 0.0000 C . �495 0.0313 0.0119 0.0131 0.0000 C . 5769 0.0311 0.0126 0.0147 0.0000 � .5044 0.0310 0.0132 0.0165 0.0000 �� .5319 0.0308 0.0138 0.0185 0.0000 �� .5593 0.030� 0.0145 0.0205 0 .0000 �� .0868 0.0305 0.0151 0 .0227 0 .0000 _i . �143 0.0304 0.0157 0 . 0250 0 .0000 u . �418 0.0302 0.0164 0 . 0275 0.0000 C . 7692 0.0301 0.0170 0 . 0301 0.0000 C . 7967 0.0300 0.0177 0 . 0328 0.0000 C . 8242 0 .0298 0.0184 0. 0357 0.0000 C . 3516 0 . 0297 0.0190 0.0388 0.0000 � . 3791 0 . 0295 0.019� 0.0420 0.0000 �� . �066 0 . 0294 0.0203 0.0453 0.0000 �� . 9341 0.0292 0.�210 0.0488 0.0000 �i .9615 0.0291 0.0217 0.0524 0.0000 0 .9890 0.0289 0.0224 0.0563 0 .0000 1 .C165 0.0288 0.023G 0.0602 0 .0000 1 .G440 0.0286 0.02?7 0. 0644 0 .0000 1 .0714 0.0285 0.0244 0 . 068`7 0.0000 1 .0989 0.0284 0.0251 0 . 0731 0.0000 1 . �264 0. 0282 0.0258 0. 0778 0.0000 _ . 1538 0 . 0281 0.0265 0.0826 0.0000 _ . 1813 0 . 0279 0.0272 0.0876 0.0000 � .2088 0. 0278 0.0279 0.0927 0.0000 1 .2363 0. 0276 0.0286 0.0981 0.0000 1 .263`7 0.0275 0.0293 0.1036 0.0000 1 .2912 0.0274 0.0300 0.1093 0.0000 1 .3187 0.0272 0.0307 0.1152 0.0000 1 .3462 0.02`71 0.0314 0.1212 0.0000 1 .3736 0.0269 0.0322 0.1275 0.0000 1 .4011 0.0268 0.0329 0 .1339 0.0000 1 .4286 0.0266 0.033E 0 . 1406 O.0000 1 . 4560 0.0265 0.0343 0 . 1474 0 .0000 ,_ . 4835 0 . 0264 0.0351 0 . 1544 0 .0000 = . 5000 0 . 0262 �.C?55 0 . 1586 O .OG�O Surface INGARDEN - 1 Hydraulic Table Stage(ft) Area(ac) Volume(ac-ft) Discharge(cfs) To Amended(cfs) Wetted Surface i 1 .5G00 C.0342 0.0355 G. 00OG 0 .1615 C .OG56 � 1 .5275 0.0343 0.0365 0.0000 0 .1615 G.OG56 1 .5549 0.0345 0.03�� 0. 0 0 .1644 0.0056 1 .�-24 O . r�cF n . "�38 OT �1. d�TED� .�F.�� C . 0056 FOR ASBUILT I � i , 1.6099 0. 0348 0.0393 0.0000 0.1702 0. 0066 1 .6374 0.0349 0.0403 0.0000 0.1731 0.0066 1 .6648 0.0351 0.0412 0.0000 0.1760 0.0066 1 .6923 0.0352 0.0422 0.0000 0.1789 0.0�66 1 . 7198 0.0354 0.0432 0.0000 0.1818 0.0066 1 . 7473 0.0355 0.0441 0.0000 0.1847 0.0066 1 . 7747 0.0357 0.0451 0.0000 0.1876 0.0066 1 . B022 0.035g 0.0461 0.0000 0.1905 0.0066 1 . 8297 0.0360 0.0471 C .0000 0 .1934 0.0066 - 1 . 8571 0.0361 0.0481 C.0000 0 .1963 0.0066 1. 8846 0.0363 0.0491 0.0000 0 .1992 0.0066 1. 9121 0.03E4 O.G501 0.0000 0 .2021 0.0066 1.9396 0.0366 O.G511 O. 0000 0 .2050 0.0066 1.9670 0.0367 0.0521 0. 0000 0 .2080 0.0066 1.9945 0.0369 0.0531 0.0000 0 .2109 0.0066 2.0220 0 .0370 0.0541 0.0000 0 .2138 0.0066 2.0495 0 .0372 0.0551 0.0000 0 .2167 0.0066 2.0769 0 .0373 0.0561 0 .0000 0 .219E 0.6066 2.1044 0 . 0375 0.0572 0.0000 0 .2225 0.0066 2.1319 0 . 0377 0.0582 0.0000 0 .2254 0.0066 2.1593 0 . 0378 0.0592 0.0000 0 .2283 0.0066 2.1868 0 . 0380 0.0603 0.0000 0 .2312 0.0066 2.2143 0 . 0381 O.D613 0.0000 0 .2341 0.0066 2.2418 0 . 0383 0.0624 0.0000 0 .2370 0.0066 2.2692 0 . 0384 0.0634 0.0000 0 .2399 0.0066 2.2967 0 . 0386 0.0645 0.0000 0 .2426 0.0066 2.3242 0. 0387 0.0655 0.0000 0 .�457 O.OD66 2.35"�6 0. 0389 0.0666 0.0000 0 .2486 0.0066 2.3791 0. 0390 0.06�� 0.0000 0 .2515 0.0066 2.4C66 0. 0392 0.0688 0.0000 0 .2544 0.0066 2.4341 0. 0393 0.0698 0.0000 0 .2573 0.0066 2.4615 0. 0395 0.0709 0.0000 0 .2602 0.0066 2 .4�90 0. 039� 0.0720 0.0000 0 .2631 0.0066 2 .5G00 0. 039� 0.0724 1 .9835 0 .2643 O. C�OG -- Name : Sur�ace INGARC-� - 1 Element Flows To: Outlet 1 Outlet 2 RAINGARDEN - 1 ANALYSIS RESULTS _ Stream Protection Duration , Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.528 Total Impervious Area:1.172 ' FOR ASBUILT � ; Mitigated Landuse Totals for POC #1 Total Pervious Area:0.528 Total Impervious Area:1.172 Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year C . �805?2 5 year C .520322 10 year � .�16785 ii ' 25 year 0.843547 'I 50 year G.941678 I 100 year = . G43094 � Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.249628 5 year 0 .4031;6 10 year 0 .64866� 25 year 0 .938781 50 year 1 .198947 100 year 1 .499888 Stream Protection Duration Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0 .65� G. 342 "�9�0 O .G3� 0. 3=2 _951 0 .4CE 0.4i9 _952 0 .327 0.121 _953 0 .354 0.120 "�954 0 .392 0.120 1955 0 . 436 0.386 1956 0. 431 0.338 1°57 0. 510 0.527 1°58 0.390 0.248 1959 0.379 0.121 1°'00 0.423 0.441 190'1 0.430 0.121 1°'02 0.354 0.120 1°03 0.416 O.i21 1°64 D.389 0 .122 1965 0.5:i1 0 .174 1966 D.335 0 .120 1967 0.585 0 .601 1968 0.6�6 0 .122 1969 0.483 0 .207 1':70 D.449 0 .120 1971 0.536 0 .121 1y72 0.597 C .467 1y73 0.311 C .120 1y74 0.500 C .121 1�75 0.522 C .529 'a76 0.38� C.121 ��?' 0.381 I�C�� UPDATED _y,e o . ��h FOR ASBUILT 1979 0.646 0 .122 1980 0.677 C .450 1981 0.497 C.246 1982 0.724 �. 743 1983 0.555 �.370 1984 0.363 0. 121 1985 0.499 0.219 1986 0.418 G. 431 1987 0.640 0.449 1988 0.378 0.121 1989 0 .473 0.120 1990 0 .995 1.026 1991 0 . 760 0.784 1992 O .s60 0.230 1993 0 .301 0.120 1994 0 .315 0.120 1995 0 . 438 0.306 1996 0 .504 0.469 1997 0 . 479 0.360 1998 0 . 451 0.121 1999 0. 992 0.612 2000 0 . 480 0.328 2001 0.495 0 .120 2002 C .696 0.664 2003 C.502 0 .121 2004 0.921 0 .956 2005 0.423 0 .436 2006 0.381 0 .312 2007 0.888 0 .906 2C08 0. �46 0 . 764 2009 0.579 0 .515 Stream Protection Duration Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.9948 1 .026� 2 0.9924 C .95�? 3 0.9205 C.90�i 4 0.8880 C. 783� 5 0. 7601 C. 7635 6 0.7462 C. 74�r ' i 0.7243 C .66=�� 8 0.6765 C .612G 9 0.6664 C .600r 10 0.6553 C .529�� 1"��, 0.6460 C .52-� '� 12 0.6455 C .51=� 13 0.6399 C .48_-: ' 14 0.6376 C .4'o'�- ', 15 0.5970 0 .4'or �' I, 16 0.5847 C .45i �� 17 0.5�90 0 .4�'= 18 0.5549 0 .4�_ 19 0.5362 0 .43: �� 0.52�2 I�C��-�l.1PDATEi FOR ASBUIL� 22 0 .51�3 � .385° 23 0 .5043 �.3�G1 I 24 0 . 5018 0.36G3 I 25 0. 5000 0.34�? I 26 0.4988 0.3384 ' 2'7 0.4974 0.327? 28 0.4954 0.3121 29 0.4826 0.311? 3G 0.4802 0.305� 3= 0.4791 0.2482 32 0.4756 0.24E2 33 0.4728 0.2�G0 34 0 .4509 0.2195 35 0 .4491 0.20�1 35 0 . 4378 0.1744 _ � 0 . 4362 0 .1222 38 0 . 4314 0 .1219 �9 0 . 4298 C .1219 40 0. 4227 0.1214 41 0. 4227 0.1213 42 0.4179 0.1212 43 0 .4161 J.1211 �4 0.4078 0.1210 _� 0.3918 0. 1209 �F 0.3898 0. 1207 _ , 0.3889 0. 1207 _� 0.3866 0. 1207 <9 0.3810 0.1207 �� 0.3806 0.1206 51 0.3789 0.1206 52 0.3781 0.1205 53 0 .3629 0.1204 �4 0 .3595 0.1204 55 0 .3539 0.1203 50' 0 .3535 0.1202 �? 0 .3355 0.1202 58 0 .3274 0.1202 59 0 .3155 0.1198 5C C .3106 0.1198 51 C.3014 0.1196 Stream Protection Duration POC #1 The Facility PASSED The Facility PASSED. Flow(cfs) Predev Mit Percentage Pass/Fail C .2403 1695 531 31 Pass C .2474 i533 49i 32 Pass C .2545 i378 462 33 Pass 0 .2616 �237 432 34 Pass C .2687 1113 399 35 Pass C .2758 1017 373 36 Pass C .282� 936 342 36 � .�w�� Q�; ��o �� NC��sIJPDATED FOR ASBUILT 0.2970 759 305 40 Pass 0.3041 705 295 41 �ass 0.3112 652 280 42 Pass 0.3183 596 263 44 Pass 0.3253 554 241 43 Pass 0.3324 518 223 43 Pass 0.3395 475 214 45 Pass 0.3466 439 204 46 Pass � 0.3537 408 191 46 Pass ! 0.3608 377 �79 47 Pass ! 0.3679 356 166 46 Pass 0.3749 340 156 45 Pass 0 .3820 305 147 48 Pass 0 .3891 286 143 50 Pass 0 .3962 261 137 52 Pass 0 .4033 246 127 51 Pass 0.4104 229 121 52 Pass 0.9174 214 117 54 Pass 0.4245 198 114 57 Pass 0.4316 191 107 56 Pass 0.4387 175 101 57 Pass 0.4458 165 95 57 Pass 0.4529 152 93 61 Pass 0 . 4599 144 8� 60 Pass 0 . 4670 133 82 61 Pass I 0 . 4741 127 79 62 Pass 0. 4812 118 �6 64 Pass 0. 4883 1G9 �1 65 Pass 0.4954 103 69 66 Pass 0.5025 98 65 66 Pass 0.5095 92 64 69 Pass 0.5166 86 63 73 Pass 0.5237 81 60 74 Fass 0.5308 79 56 70 Pass 0.5379 76 54 71 Pass 0 .5450 76 52 68 Pass 0 .5520 71 51 71 Pass 0 .5591 66 50 75 Pass 0.5662 65 49 75 Pass 0.5733 61 47 77 Pass 0.5804 57 44 77 Pass 0.5875 53 44 83 Pass 0.5945 5i 42 82 Pass 0.6016 49 39 79 Pass 0.6087 47 38 8� Pass 0.6158 43 34 79 Pass 0.6229 41 33 80 Pass 0 .6300 38 29 �6 Pass 0 .6371 35 28 80 Pass 0 .6441 33 27 81 Pass 0 .6512 29 26 89 Fass 0.6583 26 24 92 Fass 0.6654 26 22 84 Pass 0.6725 23 22 95 Pass 0.6796 21 19 90 Pass 0.6966 i� i8 9� NC��sUPDATED FOR ASBUILT 0 . 7008 18 16 88 Pass C . 7079 17 14 82 Pass C . �150 1� 14 82 Pass C . 7221 14 13 92 Pass C . 7292 13 12 92 Pass C . 7362 12 12 100 Pass C . �433 12 10 83 Pass C . 7504 9 8 88 Pass C . 7575 9 8 88 Pass C . 7646 8 6 75 Pass C . 7717 8 6 75 Pass C. 7787 8 6 75 Pass C . 7858 8 5 62 Pass � . 7929 8 5 62 Pass � .5000 8 5 62 Pass C . 8071 8 5 62 Pass G. 8142 7 5 71 Pass � . 8212 7 5 71 Pass � . �283 7 5 71 Pass � . 8354 7 5 �1 Pass C . 8425 7 4 57 Pass G . 8496 7 4 57 Pass C . �567 7 4 57 Pass � . 3638 7 4 57 Pass �� .3708 6 4 66 Pass � .8779 6 4 66 Pass � . 8850 5 4 80 Pass � . 8921 4 9 100 Pass :� . 8992 4 4 100 Pass u . 9063 4 3 75 Pass G .9133 3 2 66 Pass 0 .92C4 3 2 66 Pass � .92'75 2 2 100 Pass � .9346 2 2 100 Pass �. 9417 2 2 100 Pass Water Quality S1� Flow and Volume for POC #1 On-line facility volume: 0 acre-feet On-line facility target flow: G cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: � cfs. Adjusted for 15 min: 0 cfs. Wetlands Fluctuation for POC 1 Average Annual Volume (acft) Month Predevel Mitigated Percent Pass/Fail Jan 31.6212 31.6588 100.1 Pass Feb 20.9696 21.0620 100.4 Pass Mar 17.1412 17.1278 99.9 Pass Apr 9.8402 9.7322 98.9 Pass May 5.0142 4.7903 95.5 Pass Jun 4.2912 4.1115 95.8 Pass Ju� 1.8406 1.�1�5 9��T�PDATED FOR ASBUILT Aug 3.4471 3.2683 94.8 Pass Sep 5.7137 5.5281 96.8 Pass Oct 14 .8172 14. 6225 98.7 Pass Nov 32.0987 32.0780 99.9 Pass Dec 32.5439 32.6906 100.5 Pass Day Predevel Mitigated Percent Pass/Fail Janl 1.3484 1.2929 95.9 Pass 2 0.8675 0.9146 105.4 Pass 3 1.0373 1.0158 97.9 Pass 4 1.2483 1.2648 101.3 Pass 5 1.0707 1.0748 100.4 Pass 6 1.2932 1.2733 98.5 Pass 7 0. 9605 0.9870 102.8 Pass 8 1.0575 1.0877 102.9 Pass 9 0.8906 0.8631 96.9 Pass 10 0.8095 0.8101 100.1 Pass 11 0.9001 0.9392 109.3 Pass 12 1.1265 1.0607 94.2 Pass 13 1.3589 1.3543 99.7 Pass 14 1.0600 1.1166 105.3 Pass 15 0.9717 0. 9978 97.5 Pass 16 1.0037 1.0433 103.9 Pass 17 1.0787 1.0422 96.6 Pass 18 1.1070 1.1776 106.4 Pass 19 1.0143 1.0145 100.0 Pass 20 0.9185 0.9299 100.7 Pass 21 0.8856 0.8655 97.7 Pass 22 1.2070 1.1312 93.7 Pass 23 1.1906 1.2595 105.8 Pass 24 0.8400 0.8615 102.6 Pass 25 0.7823 0.7786 99.5 Pass 26 0.8019 0.8016 100.0 Pass 27 0.8186 0.8257 100.9 Pass 28 1.0043 0.9779 97.4 Pass 29 0.9846 1.0347 105.1 Pass 30 1.0886 0.9849 90.5 Pass 31 0.8310 0.9293 111.8 Pass Febl 0.7777 0.8019 103.0 Pass 2 0.6200 0.5923 95.5 Pass 3 0.6499 0.6963 107.1 Pass 4 0.5154 0.5022 97.5 Pass 5 0.7783 0.7290 93.7 Pass 6 0.7395 0.7544 102.0 Pass 7 1.0329 1.0043 97.2 Pass 8 0.7769 0.8434 108.6 Pass 9 0.6918 0.6687 104.2 Pass 10 0.5892 0.5435 92.2 Pass 11 0.8618 0.8489 98.5 Pass 12 0.7167 0.7492 104.5 Pass 13 0.6579 0.6101 92.7 Pass 14 0.8218 0.7849 95.5 Pass 15 0.9563 0.9428 98.6 Pass 16 0.8343 0.8656 103.7 Pass 17 0.9193 0.8773 95.4 Pass �s �.02�2 1.0591 lo��T�DATED ' 19 0.6312 0.7149 11 I FOR ASBUILT 20 0. 6963 0.6687 96. 0 Pass 21 0. 6145 0.6256 101.8 Pass 22 0.6581 0.6422 97.6 Pass 23 0.7623 0.7928 104.0 Pass 24 0.7032 0.6857 97.5 Pass 25 0.5800 0.5873 101.3 Pass 26 0.7005 0.7296 104.2 Pass 27 0.7150 0. 6701 93.7 Pass 28 0.6198 0.5957 88.1 Pass 29 0.6210 0.6447 103.8 Pass Marl 0.5922 0.5941 100.3 Pass 2 0.8547 0.7891 92.3 Pass 3 0.6475 0.6851 105.8 Pass 4 0.7730 0.7803 100.9 Pass 5 0.4050 0.4661 115.1 Pass 6 0.4613 0.4639 100.6 Pass 7 0.6148 0.5536 90.0 Pass 8 0.7428 0.7164 96.4 Pass 9 0.6569 0.6590 100.3 Pass 10 0.7216 0. 6991 96.9 Pass 11 0.8270 0.8353 101.0 Pass 12 0.5255 0.5474 104.2 Pass 13 0.5553 0.5543 99.8 Pass 14 0.6278 0.6363 101.4 Pass 15 0.5211 0.4993 95.8 Pass 16 0.4908 0.5219 106.3 Pass 17 0.6001 0.5539 92.3 Pass 18 0.9132 0.4607 111.5 Pass 19 0.9026 0.3978 98.8 Pass 20 0.2996 0.3317 110.7 Pass 21 0.6262 0.5639 90.1 Pass 22 0.6421 0.6329 98.6 Pass 23 0.5784 0.5500 95.1 Pass 24 0.4354 0.4892 112.9 Pass 25 0.4323 0.4354 100.7 Pass 26 0.4116 0.4173 101.9 Pass 27 0.4074 0.3540 86.9 Pass 28 0.4860 0.5020 103.3 Pass 29 0.4283 0.9464 104.2 Pass 30 0.3417 0.3470 101.5 Pass 31 0.3686 0.3561 96.6 Pass Aprl 0.3544 0.3442 97.1 Pass 2 0.3733 0.3404 91.2 Pass 3 0.5538 0.5414 97.8 Pass 4 0.4425 0.5013 113.3 Pass 5 0.3891 0.3887 99.9 Pass 6 0.2514 0.2476 98.5 Pass 7 0.9056 0.3783 93.3 Pass 8 0.9478 0.4646 103.7 Pass 9 0.2870 0.2746 95.7 Pass 10 0.3573 0.3546 99.3 Pass 11 0.3397 0.3199 95.6 Pass 12 0.4326 0.3997 92.9 Pass 13 0.3287 0.3259 99.1 Pass 19 0.2914 0.2843 97.6 Pass 15 0.4412 0.4384 9 . P �6 o.32a� 0.3769 ��1�T�DATED FOR ASBUILT 17 0.1685 0.1559 92.5 Pass 18 0.5744 0.4985 86.8 Pass 19 0.2487 0.3192 128.4 Fail 20 0.1515 0.1639 108.2 Pass 21 0.3034 0.2319 76.4 Fail 22 0.3798 0.4068 107.1 Pass 23 0.2380 0.2644 111.1 Pass 24 0.1737 0.1917 110.4 Pass 25 0.1264 0.1153 91.2 Pass 26 0.3148 0.2670 84.8 Pass 27 0.1798 0.2057 114.4 Pass , 28 0.3035 0.2644 87.1 Pass I 29 0.2918 0.3108 106.5 Pass � 30 0.2651 0.2357 88.9 Pass Mayl 0.1803 0.1832 101.6 Pass 2 0.1397 0.1647 117.9 Pass 3 0.1817 0.1556 85.6 Pass 4 0.1888 0.1864 98.7 Pass 5 0.2110 0.2261 107.1 Pass 6 0.1368 0.1245 91.0 Pass , 7 0.1086 0.1037 95.5 Pass 8 0.1129 0.1072 95.0 Pass ' 9 0.1284 0.1073 83.6 Pass 10 0.2009 0.1930 96.1 Pass ' � 11 0.1050 0.0777 74.0 Fail ' 12 0.1239 0.1484 119.8 Pass 13 0.2010 0.1853 92.2 Pass 14 0.1522 0.1386 91.1 Pass 15 0.1256 0.1389 110.5 Pass 16 0.1203 0.1112 92.4 Pass 17 0.1588 0.1212 76.3 Fail 18 0.2051 0.1709 83.3 Pass 19 0.1199 0.1534 128.0 Fail 20 0.0908 0.0885 97.4 Pass 21 0.0861 0.0998 115.9 Pass 22 0.1495 0.1171 78.3 Fail 23 0.1566 0.1368 87.4 Pass 24 0.0822 0.0978 118.9 Pass 25 0.2164 0.1599 73.9 Fail 26 0.1644 0.1942 118.2 Pass 27 0.1587 0.1435 90.4 Pass 28 0.2559 0.2210 86.4 Pass 29 0.2430 0.2229 91.7 Pass 30 0.2451 0.2759 112.5 Pass 31 0.2084 0.1975 99.7 Pass Junl 0.1507 0.1570 104.2 Pass 2 0.2320 0.2070 89.2 Pass i 3 0.2360 0.2346 99.4 Pass j 4 0.1205 0.1171 97.2 Pass I 5 0.2340 0.1757 75.1 Fail I 6 0.2110 0.2686 127.3 Fail ! 7 0.1703 0.1541 90.5 Pass ' 8 0.1902 0.1709 89.8 Pass 9 0.1916 0.2019 105.4 Pass 10 0.1959 0.1651 89.3 Pass 11 0.1698 0.1793 10 . P �2 0.0596 0.o�� 3 . T�DATED FOR ASBUILT 13 0.0501 0.0423 84.3 Pass 14 0.0910 0.0677 74.5 Fail 15 0.1015 0.0980 96.6 Pass I 16 0.1781 0.1401 78.7 Fail 17 0.0634 0.0930 146.6 Fail ' 18 0.0659 0.0618 93.7 Pass 19 0.1285 0.1124 87.5 Pass ' 20 0.1361 0.1446 106.3 Pass 21 0.0813 0.0780 95.9 Pass 22 0.1017 0.0925 90.9 Pass 23 0.3506 0.2977 84.9 Pass 24 0.1091 0.1425 136.9 Fail 25 0.0682 0.0583 85.5 Pass � 26 0.0744 0.0605 81.3 Pass 27 0.1102 0.0985 89.4 Pass 28 0.1008 0.1151 114.1 Pass ' 29 0.1157 0.1019 88.1 Pass 30 0.1317 0.1311 99.6 Pass Jull 0.0815 0.0694 85.1 Pass 2 0.0760 0.0814 107.1 Pass 3 0.0490 0.0434 88.7 Pass 4 0.0921 0.0695 75.4 Fail 5 0.0373 0.0535 193.4 Fail 6 0.0753 0.0367 48.8 Fail 7 0.0980 0.1138 116.0 Pass 8 0.1214 0.0949 78.2 Fail 9 0.0702 0.0595 84.7 Pass �' 10 0.0259 0.0380 146.5 Fail 11 0.1230 0.1148 93.4 Pass 12 0.0896 0.0994 111.0 Pass ' 13 0.0830 0.0615 74.1 Fail 14 0.0098 0.0349 354.2 Fail 15 0.1744 0.1232 70.7 Fail 16 0.0962 0.0775 167.7 Fail 17 0.0210 0.0177 84.2 Pass 18 0.0513 0.0335 65.3 Fail 19 0.0367 0.0409 111.3 Pass 20 0.0207 0.0180 86.8 Pass 21 0.0500 0.0469 93.8 Pass 22 0.0312 0.0323 103.6 Pass 23 0.0156 0.0162 103.9 Pass 24 0.0228 0.0184 80. 6 Pass 25 0.1236 0.0980 79.3 Fail 26 0.0288 0.0375 130.0 Fail 27 0.0240 0.0278 115.6 Pass 28 0.0053 0.0073 137.1 Fail 29 0.0145 0.0052 35.9 Fail 30 0.0108 0.0155 194.5 Fail 31 0.0546 0.0419 76.7 Fail Augl 0.0754 0.0524 69.5 Fail 2 0.0997 0.0997 100.0 Pass 3 0.0493 0.0592 120.2 Fail 4 0.0129 0.0189 148.0 Fail �I 5 0.1096 0.0823 75.0 Fail 6 0.1248 0.1089 87.2 Pass I, 7 0.0168 0.0408 24 . F I s o.ioo6 o.o�so ��T�DATED �, FOR ASBUILT 9 0.0219 0.0355 162.4 Fail 10 0.0429 0.0314 73.3 Fail 11 0.0405 0.0375 92.7 Pass 12 0.0245 0.0266 108.7 Pass 13 0.1533 0.1323 86.3 Pass 14 0.1799 0.1651 91.8 Pass 15 0.0565 0.0522 92.3 Pass 16 0.0928 0.1075 115.8 Pass 17 0.1690 0.1416 83.8 Pass 18 0.1471 0.1190 80.9 Pass 19 0.0691 0.1036 199.9 Fail 20 0.1392 0.0862 64.3 Fail 21 0.1971 0.1991 101.0 Pass 22 0.3085 0.2822 91.5 Pass 23 0.2000 0.2008 100.9 Pass 24 0.1447 0.1750 121.0 Fail 25 0.1793 0.1672 93.3 Pass 26 0.1693 0.1501 88.7 Pass 27 0.1200 0.1237 103.1 Pass 28 0.1664 0.1338 80.4 Pass 29 0.0891 0.1303 146.2 Fail 30 0.0979 0.0860 87.8 Pass 31 0.1368 0.1175 85.8 Pass Sepl 0.1604 0.1805 112.5 Pass 2 0.1020 0.0888 87.0 Pass 3 0.1831 0.1756 95.9 Pass 4 0.0805 0.0699 86.9 Pass 5 0.1689 0.1558 92.3 Pass 6 0.0316 0.0540 170.7 Fail 7 0.1591 0.1175 73.9 Fail 8 0.0965 0.1185 122.9 Fail 9 0.2064 0.1512 73.3 Fail 10 0.1306 0.1690 129.4 Fail 11 0.0589 0.0728 123.6 Fail 12 0.0853 0.0650 76.2 Fail 13 0.2157 0.1717 79.6 Fail 19 0.1237 0.1305 105.5 Pass 15 0.1565 0.1356 86.6 Pass 16 0.4780 0.4161 87.0 Pass 17 0.1971 0.2429 123.2 Fail 18 0.2519 0.2378 94.4 Pass 19 0.2178 0.2001 91.9 Pass 20 0.1795 0.2218 123.6 Fail 21 0.3946 0.3225 81.7 Pass 22 0.2572 0.3156 122.7 Fail 23 0.2283 0.2036 89.2 Pass 24 0.2055 0.1920 93.4 Pass 25 0.2212 0.2400 108.5 Pass 26 0.2272 0.1773 78.0 Fail 27 0.2571 0.2989 116.1 Pass 28 0.1628 0.1476 90.7 Pass 29 0.3400 0.3385 99.6 Pass 30 0.1965 0.2014 102.5 Pass Octl 0.2043 0.2067 101.2 Pass 2 0.2938 0.2284 77.7 Fail 3 0.4095 0.3879 9��T�DATED 4 0.2904 0.3023 10 FOR ASBUILT 5 0.5803 0.5563 95.9 Pass 6 0.2883 0.3091 107.2 Pass 7 0.6344 0.5827 91.8 Pass 8 0.5941 0.5741 96.6 Pass 9 0.5170 0.5026 97.2 Pass 10 0.2435 0.3205 131.7 Fai:G 11 0.2739 0.2655 97.0 Pass 12 0.3037 0.3123 102.9 Pass 13 0.3223 0.2782 86.3 Pass 14 0.2779 0.3264 117.4 Pass 15 0.3200 0.3019 94.3 Pass 16 0.5100 0.4461 87.5 Pass 17 0.4382 0.4444 101.4 Pass 18 0.5910 0.5792 98.0 Pass 19 1.0247 0.9516 92.9 Pass 20 0.6576 0.7072 107.5 Pass 21 0.5606 0.5476 97.7 Pass ' 22 0.4663 0.5094 109.2 Pass - 23 0.4936 0.4946 100.2 Pass 24 0.5336 0.4866 91.2 Pass 25 0.6363 0.6728 105.7 Pass 26 0.7445 0.6824 91.7 Pass 27 0.6561 0.6855 104.5 Pass 28 0.5876 0.6092 103.7 Pass 29 0.4526 0.4654 102.8 Pass _ 30 0.7169 0.6847 95.5 Pass 31 0.6322 0.6481 102.5 Pass Novl 0.8095 0.7371 91.1 Pass 2 1.0951 1.0416 95.1 Pass 3 1.0919 1.0903 99.9 Pass 4 0.6646 0.7628 114.8 Pass 5 1.0267 0.9600 93.5 Pass 6 0.8061 0.9015 111.8 Pass 7 0.7393 0.6939 93.9 Pass 8 1.0570 1.0141 95.9 Pass 9 1.1016 1.0955 99.4 Pass 10 1.3590 1.2928 95.1 Pass 11 1.2251 1.3003 106.1 Pass 12 1.2188 1.1513 94.5 Pass 13 1.0227 1.1578 113.2 Pass 14 0.8U59 0.7595 94.2 Pass 15 1.0530 1.0526 100.0 Pass 16 1.0309 1.0116 98.1 Pass 17 0.9079 0.9694 106.8 Pass 18 1.4493 1.3399 92.5 Pass 19 1.3659 1.4258 104.4 Pass 20 1.0060 1.0741 106.8 Pass 21 0.9421 0.9413 99.9 Pass 22 1.4061 1.2254 87.1 Pass 23 1.5476 1.6560 107.0 Pass 24 1.5466 1.5317 99.0 Pass 25 1.1255 1.1633 103.4 Pass 26 0.9818 1.0512 107.1 Pass 27 0.8619 0.8344 96.8 Pass 28 0.9910 0.9905 100.0 Pass 29 1.2300 1.2049 9 . P 30 �.�202 1.0749 9 . T�DATEC� FC)R A��!�_ T Decl 1.1892 1.2484 105.0 Pass I 2 1.5147 1.5023 99.2 Pass 3 0.8995 1.0100 112.3 Pass 4 1.1598 1.0663 91.9 Pass 5 0.9622 1.0306 107.1 Pass 6 0.6353 0.8468 101.4 Pass 7 0.8983 0.8971 99.9 Pass 8 1.0598 1.0496 99.0 Pass , 9 1.2265 1.1980 97.7 Pass ' 10 1.1487 1.1205 97.5 Pass 11 1.1816 1.2010 101.6 Pass 12 1.1884 1.1749 98.9 Pass 13 1.2000 1.1776 98.1 Pass 14 1.3734 1.4562 106.0 Pass 15 1.0788 1.0857 100.6 Pass 16 0.8685 0.9077 104.5 Pass 17 0.8470 0.8501 100.4 Pass 18 0.8866 0.8528 96.2 Pass 19 1.1785 1.1506 97.6 Pass 20 1.0420 1.0936 105.0 Pass 21 0.9047 0.9160 101.3 Pass 22 0.9616 0.9691 100.8 Pass 23 0.8186 0.8331 101.8 Pass 24 0.9101 0.8695 95.5 Pass 25 1.1934 1.1496 96.3 Pass 26 1.1453 1.2253 107.0 Pass 27 0.6840 0.7173 104.9 Pass 28 1.1531 1.0486 90.9 Pass 29 1.1598 1.2719 109.7 Pass 30 0.7568 0.6973 92.1 Pass 31 0.8975 0.9341 104.1 Pass Perind and Impind Changes Vc changes have been made. Tris program and accompanyir,g documentation are provided 'as-is' without warranty of any kind. The er.=ire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. =r� no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without =ir�itation to damages for loss of business profits, loss of business information, business _�terruption, and the like) arising out cf the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such ca�a��s. Software Ccp_yrig�t � by : Clear Creek Solu�ions, Inc. 2005-2013; All Rights Beserved. NOT UPDATED FOR ASBUILT KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL Water Quality: RAIN GARDEN - 2 Type/Number of water quality facilitiesBMPs: biofiltration swale sand filter(basic or large) larg �umbiu�ci �icteilli�lvw�ctpuiiu ��riu tiltei ��ault (basic �r large) (wetpond portion basic or large) sand bed depth (inches) combined detention/wetvault stormwater wetland filter strip storm filter flow dispersion wetpond(basic or large) farm management plan wetvault landscape management plan Is facility Lined? oiUwater separator If so, what marker is used above X RAIN GARDEN (baffle or coalescing plate) Liner? catch basin inserts: Manufacturer pre-settling pond pre-settling structure: Manufacturer high flow bypass structure (e.g., flow-splitter catch basin) source controls Design Information Water Quality design flow Water Quality treated volume(RAIN GARDEN) 53.578 AC-FT Water Quality storage volume (wetpool) Facility Summary Sheet Sketch AS B U I LT 2009 Surface Water Design Manual 1/9,'2009 3 • 1wE 2 CB - e0� �/4 SECTION NW 32 TOWNSHIP 23 RANGE OS STORM DRAINAGE NOTES: i ' STA 21+36.26, 55.4 RT. TYPE 1 CB - 900 �\ � ' � - -�_ - RIM 38242 �' � STA 21+37.44, 44.94 RT. 6'IE 380.40 1. HORIZONTAL CONIROL FOR STRUCTUftES 3. STORM DRAIN PIPE CROSSING UNDER THE o ,i��\ � z� fT dc 8' IE 3?639-Ef}NF�76.47 (YI� ' � RIM 3�964379.95 6'PERF PYC PIPE ADJACENT TO CURB IS PROVIOED BY BUIIDING SHALL BE INSTALLED iHRWGH � �2'iE �s-as 37 .4) N WT � 12' IE 3iE44 515.50 TA o.ox STATION ONLY. CONTRACTOR SHALL lAY AN 18' DUCi1LE IRON SLEEVE E7fTENDING ,��, � 12� � 376.4J S � �` 6�-g� tE 3afr44 3�6.J��N�IN OUT CURB LJNE TO DETERMINE DfACT IMNIMUTA 5' OUTSIDE 1HE i00TING .e �� OFFSET NECESSARY FOR WTSIDE OF SUPPORT. COORqNAiE INSTALLAlION OF �o„��,� • � FRAYE TO AUGN WITH FACE OF CURB. THE SLEEVE WITH SiRUCTURE PLANS fOR 4i `� � `$ � � RAIN GARDEN - 2 �� RAMI GARDEN - 1 HORIZONTAL CONTROL FOR STRUCTURES POlENTIAL IAODIFICATION OF THE .c�;�� w �� - �2 ' UPPER WSEL 379.69 �� UPPER WSEL 381.40 NOT ADJACENT TO CURB REFERS TO SiRUC1URAL FOOIING. � �3 0�, o � STA 20+59.73, 41.29 RT. � '^ R��'� OTTOAI ELEV 378.69 gp��y 380 4D � CENTER OF STRUCTURE. c c� ' r 13 LF 12' HDPE SD 0 0.67G QEWIRED BOTTOAI AREA 67 SF 4. ALL PIPE OUTFALLS SHALL INCIUDE DEBRI c; �°�, ; i2' iE �s�s 37 . (N) OUT �r �Q�1�Rm BOTTOM AREA 1,iai sF d�PERF PVC PIPE A O.Ox �`"`*�-�-0 i 2 iRENCH DRAIN RIN ELEVAlIONS SHONM BARRIERS AND 4'-6'QUARRY SPALL �� 12' IE 376.3B gS�IN i ��- i �_ ��p REFER TO CENTER DF 1RENCH DRAIN WTFALL PROiEC110N, MINIMUTA 2' WIDE BY Q�"�' SEE SHEET C10.2 FOR 19 � ! FLpyy CONTROL STRUCTURE B pp+pp �+ � _ .--�--� ` �"} p` � CATCH BASIN. RffER TO GRADING PLAN 4' LONG OR TO TOE OF SLOPE WHICHEVER �3`r w ADDITIONAL STORM DRAIN }�--IF333�@ C6.3 iFtENCH DRAIN - 1000 Z�+00 A TR CH DRAI�} 3 - / AND ALIGNUENT PROFlLES FOR REMAINING IS GREAIER. i� a;`N° � I N F O R A I A 1 F O N I 1 2' I E 3 7 3.0 4 N �U� R I I� 3 8�5 6 I� "�E 37�ss 378J9-� � '� �,��) C 6.4 R I M��8 1.5 5 ',,,, ;'s: i • =-� Z /�I � �N 8-6�� iE�a-se 379.22 (S) Wl� I 10 TH PLACE SE 1� i �� '� _ = 6� IE 3B&i6 I ? 7 R E N C H G R A i E E L E V A T I O N S. 5. DETENTION POND SHALL BE CONSTRUCTED �,�� I ,. W • r' / � t • � , ', �� "'� 379.74 S i � /� AS SHOWN HEREON AND IN ACCORDANCE � � `_ 5'DRAINACE SETBACK• ,�p, . . " ' r � . '�� • • a a � � , / WITH SECTION 5.3.1.1 'DESIGN CRIiERIA' - - - - �r �! � THE 2009 KING CWNTY SURFACE WATER a , - - - - - � - ; �� ; � -„,;, - - - - - - - - T �� DESIGN MANUAL .: :.< .:. � :.. T ��,�o� �; . � � �� s -� - - r� - � . • '� � •/// G� / � qf�'y 6. PROVIUE 12' ANNIAIUM Ri1CAl f4ti�°��'��^ � ,�f_ - ' i 1� 6'DI SD - � � * � Vf I _ n '6: - �N �93 �� __ � 0&SBlF y i ,/ ��/�� / SEPARATION BETWEEN Ui1LIlY PIPES AT v4 'Y•�o `.�� -- ? '� -�- 6'& -i y;;%';b` � � y� CROSSINGS. WHERE 12" IS NOT FEASIBLE, � � N 6� CSBC OVER�I r i' _- _ . .. .. .. :��a�a y- �� '.• �I12� - _ _ \ PR AN ETHAF AIA PAD AT CROSSIN E = � � �D�E 0 G o�,�e�« ��: -- - - UTI111 . rao�° _ � _ . _ _ COMPACiED SURBGRADE �� 'I'i �� ki,�'�°��'��o�-,� e� a2 -� , ' ��- �- I�/ y � ��•� B l ES .�@�.� « . . � '' N0 � _� $ ,� . �� <�>�, I , I I I �� 'i`��'�� '��'"�`•�. . •. • /� �� --_'�-_ I } . _ ;!�, ' � 7. ALL NEW STORM DRAIN SHALL 8E NDEO ° i.�� ' � r��= � �'� , ��--- �# -�_ 6�� 'y INSPECIED. NDEOS SHALL BE SUBYITfED ��- F.E F P I I � , i, , � 4'PVC DSP ; .. 3 - � � 71+00� '�'12'IE 3B&49 `� ' (��n TO THE qTY. I � �I �I I \, 8 LF 12'HM . S , 4 CO T ik 9 LF�'r ---�'��-�� EuFLT OR Tr ^._ C OVERFIOW SIRUCNRE I I I I i 9 1.OS AIIN. A �_ _ �8Q,26 12' IF37��3 IE�i79.Q , HM� SD �__- ['� �iFJP,ti�a•�:E M1TH� � I�I I `�12' �� IE 375 98 8�dvC DSP � ' � � 0.6� ��` T�'� ♦ d' o s�t� ��TEr�T C6.3 803�8-8�378.�CAGE I� I 1 I I I I IE 37269 a. �� i , - 0 3. X , 6 , ''� „ C0� ♦ � „ M IE 378.37 18' DIP Z r M „ �V. �� 2' iE �372.8d � f � I I UPPQ2 y�L 377 IE 376 35 '/ ' �'�`� ' �� c6.a IE 376.0 � M .;- M ` B"PVC � O �S� IN I � I I I BOTTOAI OF UVE STORAGE ELEV. 3�3 371.72 ' � I� 6 PVC POC FOR IAECH= � 9 1.28x �"' H I I-��I I I OTT011 OF SEDINENT STORAGE ELEV. ',�}�5 371.13.. �. , SUMP AND PUYP , � Q � � 'I�� I i �@tl�E6 ASBUILT STORAGE VOLUIIE z^S,A54 / � � 4' PVC OSP IE 377.6 npE 1 CB - B00 � �� w Z V � h��II�I�� SEE NOiE 9/� , ; 1 A 1.Ox��. STA 21+99.2�, 48.50' RT � C = J g �� I i� �/' � TRENCH DR RIM 39��0 381.39 B' PYC DSP c � '� , � / � � � I STA fY 8" IE 379-}5(SE}IN 378.39 0 1.26X �E 1 CB - 100 o io zo �o �- � � � �� 12�IE 37&#5(N) WT 377.99 4' PVC DS POC RI� �} . ' � i+cn=zo reet � Z � �,�� - �i 362.99(NQ WT ( ) 1�2"�IE 3899�380.8�380.94��N� $ � � � i 8'PVC DONMSP(MlT FOft AIECH TYP. � Z � _ - 8'PVC DOWNSPOUT COLLECTOR (DSP)0 j eq�A DRAIN � � O � -f IE 376.9 , COLLECTOR DSP 1.Ox AIIN. ; (1YP.) 12� IE �.78 �NE� � r �� ; C6.4 CONNECT TO DSP 9 �� % O � � Q Z � � 6'BLACK NNYL COATED CHAIN - � j 9 1.07G MIN. ; 20Z MIN. SIOPE(TYP.) �� ' LLJ a W I UNK FENCE PER WSUOT SiD Y � � �% ' � (�.) D AREA DRAIN � �� Q � ' DETAIL L-20.1D-02, TYPE 3, �� / _ � C6.4 RIIA 38f�9 . Z W � Y WITH TOP RNL � _� 61}0� / � ; � � 6' IE 381.99 (SEj OUT �} LF 6' � Q�'k4 i/ � Z � ,;, , - � . . / � , ; ,' � � � ; _ - Q � / I � �'� ' ,+' � T SDA2. ' ; , ,: O;' -- � , - i , , - 1 ' � � � �o; � o, ,� ��. �4z�o�-_ -- �E�s�_�_� ` , o�'` ��,� � g � � , I ' - - __ - _�- ' / �. j � : �'0 j��' ��;' -� !� �ti�` `^ a C.�.7 j O/ ' � � �4'.;" % I S • e � Q �/ � / �� I ,;, E .•�TYPE 1 C8 - 1�1 w 2 � O � � ; �' 2� , - ' ; I ?' - --- ti " �� V . � I � i i� %� 63+��i ^ � I �� 0 9�Q 43�pp ' �', /, STA 44+88.42 Q � Z Z . i� � ' I STA 41+92.37 �z ,_.. - „ `�, - - �- � � j Q � • � I iYPE 1 CB - 105 0 % � ltll�i 385 37 o I a ' _�� j " I 32��z�q�A' - - __�� eA��° ,./; 82.I IE�3�BN371 SE) � Z o � � I _ , � � RIA1 38�86 383.97 �`47X •' � 6 PYC DOWNSPOUT � � � Q � � C O L L E C T O R(D S P)0 1 2� I E 3 8 1.2 2 (N E) W �� , � tY iE �e2.�3 382.52(N,S� � 1.�X AIIN. � � - � - � - � - _ t `, I +� / ?Cr 7 LF 12'DI �\ -, I� TYPE 1 CB- 102 / o""'"•'��"E � 67 I 0��'�.�' - TYPE 1 C8- 104 � I %i-�'•, STA 44+06.03 DESIGN DEV. 1110&13 � ; TYPE 1 CB - 106 STA 43+20.65 TYPE 1 CB- �03 � RIM 383+3 383.52 i CooRDIr�aTtoN ovi5�ia � I �, STA 41+68.58 ttroi ��383.93 STA 43+88.86 `' 12'�3e�3+381.57 (NW, $� � BI�pNp USE REVISION 06105J14 a I - __ �. Rwi 3e�-e�384.10 = t2' iE 3e+�r 381.95 (N,S) mu 3e�se 383.66 2t �a so � � , _---- "' 8 IE 384-6�(E)iN 38270 =;�-`- � � , O B-4YlF 0. / AZADDENDUM�4 007�102114 / i 2"iE�3+(s)ouT 38265 `� ''' i z'iE�381.61 N, � �'• / �'�_ ;, , ,•�,;; ___ � un�m sEr amr��n � PRONDE 5' NINIIIUM , � � - - `CLEARANCE BEIWEEN PQtMRREVlMYLAR 08119114 g I \ ��BE� � � �g �y _ ..e ��` ---_- -- SiORAI AND SANITARY / COI�FORMCONSTSET 11/1N14 � . _ -`^:--}�� Jy1. s� ��'�\ g�.�,.F�__ _ S��S��.� � SURiACE 1REATAIENT PER ,c? � •� ¢ >� _ _"c '� -".�"� _ � ``�� --"- - CITY OF TON � �°" D�" R LANDSCAPE SLOPE PER � ''i�%'��'--�' � -- . _ REN e „vc��vma e�� 4.5� 5� AiIN.� GRADING PLANS '�;� � '�� m -- � rew-rfvsax m.n�� _ _ _ _ _ _ _ _ Approved by: Date: � �� a„+� ' �TYPE 1 CATCH BASIN 1 _ � _ _ ��g, 1210N 12' � - � = I r ' � - i I 3 3 _ _ , � Approved by: Date: � ��d� _ 0 3 �i i� is' Bio��no►i sa� - � o -- N 3 12' GRAVEL BAqcFlLL Approved by: Date: swF: ns NOTeo X W �' z -- FOR ORAINS ROT n^-� 12/10/14 _ 6'PERFORATED UNDER DRAIN Approved by: Date: �"�"�u �y � , 2-ROWS OF t/2'DIA. HOIES, Pna.uca. AGC E ' POND AND RNNGARDEN 1� oN CENIER. �� UCP U14001164 on�et 7AD AT ACCESS DRI4f HA4f 18' GRAVEL BACKFlLL FOR ...�. .e.e .� � 1HIS SEPARAl10N DRNNS AT UNDERDRAIN ,r 1N1AD AS NOTED �-^�� n Cn'y pF VANTAGE POINT APARTMENTS �z-,o-so,. 1 IAD '� � �]'�jv ON SITE IMPROVEMENT PLANS " RAIN GARDEN SECTION A � � o � r�o �� a�Tuu .�.� � ` _ �� cwur.0 Planning/Building/Public wo�ks o�Pc. DRAINAGE PLAN C6.o SCALE: 1' = 3' ,,,,.,v � �.:�. � � N0. REV510N BY DATE APPR � �` �6 61 Chris Boaio -- From: Kevin Lamb [klamb@geodesigninc.com] Sent: Tuesday, March 01, 2016 11:27 AM To: Chris Borzio Subject: RE: Vantage Point: VWMiniloggerSN29809 KCHA-29-00 In Swale-edited zoomed in FIGURE.pdf Chris Yes you can safely use the 0.4 in/hr rate. This was measured in the actual facility so no correction factors are necessary. It verifies that the actual rate is consistent with the design rate. Kevin Kevin J. Lamb, P.E., L.E.G. Principal GeoDesign, Inc. Tacoma Office 2502 Jefferson Avenue Tacoma, WA 98402 Seattle Office 10700 Meridian Avenue North, #402 Seattle.WA 98133 206.838.9900 p 206.838.9901 f 206.910-7634 m VCard w�vw.qeodesiqninc.com From: Chris Borzio [mailto:Chris.Borzio@kpff.com] Sent: Tuesday, March 01, 2016 11:08 AM To: Kevin Lamb Cc: Alberto Cisneros; 'lanced@kcha.org' (lanced@kcha.org} Subject: RE: Vantage P�int: VWMiniloggerSN29809 KCHA-29-00 In Swale-edited zoomed in FIGURE.pdf Kevin, Based on these results can we safely use the 0.4 in/hr far a design infiltration rate'? The KCSWDM has provisions for applying factors to a measured rate for long term use. Thanks, Christopher Borzio, PE, LEED Green Associate Civ�i Engineer 206.622.5822 '� 206.925.0418 1 - -------- Original message -------- �� From: Kevin Lamb <klamb(cL�eodesi�ninc.com> Date: 03/O1/2016 10:47 AM (GMT-08:00) To: Chris Borzio <Chris.Borzio(��kpff.com> Ce: Alberto Cisneros <Alberto.Cisneros��kpff.com>, "'lanced�a,kcha.org' (lanre�l��r k�ha.��r��)" <lanced(w.kcha.or�> Subject: RE: Vantage Point: VWMiniloggerSN?9809 KCHA-29-00 In S«ale-edited zoomed in FIGURE.pdf Chris Attached is revised plot I simplified it and adjusted VWP readings for manual measurement at start of monitoring period. When we installed the VWP there was no water above the base of the sensor. Kevin - Kevin J. Lamb. P E.. �. E G. , Principai GeoDesig��. Inc Tacoma Office 2502 Jefferson % Tacoma,WP Seattle Offic: 107nn f�.leri�� u�.a.su.y�uu p 206.838.9901 f 206.910-7634 m VCard www.qeodesipninc.com From: Chris Borzio [mailto:Chris.BorzioCa�kpff.com] Sent: Monday, February 29, 2016 4:27 PM To: Kevin Lamb Cc: Alberto Cisneros; 'lanced@kcha,org' (IancedC�kcha.org) Subject: RE: Vantage Point: VWMiniloggerSN29809 KCHA-29-00 In Swale-edited zoomed in FIGURE.pdf Kevin, Thanks for sending this info over to us. I have some questions/comments. 1. Since we are submitting this along with our updated AS-BUILT TIR, it would make sense to label it project specific with "Vantage Point Apartments- Rain Garden—2" as the title along with your company logo somewhere on the graph. a. It's actually a rain garden, not a bioswale. 2. Is the 0.4 in/hr the long term infiltration rate? We will need to use the long term rate for the rain garden as sediment will accumulate and slow down the initial value (similar to how factors and calculations were required to determine the pond's 0.4 in/hr design infiltration rate). z Thanks, Christopher Borzio, PE, LEED Green Associate Civil Engineer O 206.622.5822 D 206.926.0418 -----Original Message----- From: Kevin Lamb [mailto:klamb(��eodesi�ninc.com] Sent: Monday, February 29, 2016 4:14 PM To: 'lanced@kcha.org' (lanced�akcha.or�) Cc: Alberto Cisneros; Chris Borzio Subject: FW: VWMinilogger5N29809 KCHA-29-00 In Swale-edited zoomed in FIGURE.pdf Lance I was out sick last week, when 7oe was able to download the data from the bioswale. The VWP was installed in the bioswale on February 12 prior to a few significant rain events on the 12thand 13th, 15th and 16th, and the 17th. The VWP was installed below the base of the bioswale at the contact with the bioswale drain rock and the native sand subgrade. The attached plot is a summary of the VWP measurements. The measurements indicate that the depth of water accumulating in the swale is fairly shallow for the rain events that occurred during the monitoring period; generally less than a few inches above the contact between the native sand and drain rock. We calculated the infiltration rate for two periods where it was apparent rain was decreasing or had stopped and inflow into the bioswale was assumed to have stopped. The observed infiltration rate in the bioswale is about 0.4 inches per hour for the observed storm events. Kevin Kevin J. Lamb, P.E., L.E.G. Principal GeoDesign, Inc. 10700 Meridian Avenue North, #210 � Seattle, WA 98133 206.838.9900 p 206.838.9901 f 206.910-7634 m www.�eodesi�ninc.com ' Seattle WA I Longview WA I Vancouver WA I Portland OR I Salem OR I Anaheim CA II ? Please Consider the Environment before Printing this Email i The information contained in this e-mail is intended only for the individual or entity to I whom it is addressed. Its contents (including any attachments) may contain confidential and/or privileged information. If you are not an intended recipient you must not use, disclose, disseminate, copy or print its contents. If you receive this e-mail in error, please notify the sender by reply e-mail and delete and destroy the message. --------------------------------------------------------------------------------------------- --------------------------------------------- 3 KING COUNTY HOUSING AUTHORITY VANTAGE POINT APARTMENTS RAIN GARDEN #2 WATER LEVEL MONITORING __. .______----________-------------- ___---------- ---_ ____._----- - - - -----_ ��..�._.._...__...._.........................................� ... , � � � ! � �� i � i ' - 0.9 ; i 2.5 _ _ __ _.__�_._._._`_--^ � � tATMOSHPHERE CORRECTED WATER LEVEL ABOVE SENSOR a 0.8 ' , ��•CUMULATIVE PRECIPITATION � I ; E ! ' Z _. I 0.9INCHES ----_.._---- � ; PER HOUR �•� ' � in � W � '� 0.71NCHES _ Z ( � � �PER HOUR �_ _ , / � , 0.6 � , / Z 1.5 -- ...._ „ _._ - ��'+ -------- - 0.4 INCH ES ------ u+ i �► i °� �n i � � � � �ti�4 /PER HOUR u j � � � � � � , 0.5 ? p i X i I � J j I 4 �+�t. O ' W i Q � J j � ,� ' 0.4 a p� 1 i � d i 6J ' �y t—._____ __.__ _____ _.._.. . +..__ ...... ,. _+ W ,.. ....._ — __.._ i Q ! j I ; a 3 + � C�� 0.3 � }� �� { j � ' i i � I ! � 0.6 INCHES I ' � � � PER HOUR 0.2 ' 0.5 � __.... ___...._..._ --- _ _....� __ _ _ _ ..__...._�_ _ � __.__ ---- ----------- 1 • i � � i ; I i � � ' � � �. 0.1 � � � �� 0 -. �__�-I—�--, __ ._____ _:_..�-- �-- -�---�....... . .... _. �_._�-__�._ � o 2/11 2/12 2/13 2/14 2/15 2/16 2/17 2/18 � DATE ' NOTE: ESTIMATED INFILTRATION RATES BASED ON SHORT DURATION EVENTS WHERE FLOW IN TO RAIN GARDEN APPEARS TO BE MINIMAL �DE SI G N� WWHI�t2 012 PROJ$CT REPORT Project Name: SMALL RG ASBUILT Site Name: Site Address: City . Report Date: 3/10/2016 Gage : Seatac Data Start : 1948/10/O1 Data End : 2009/09/30 Precip Scale: 1. 00 Version Date: 2015/11/13 Version : 4 .2 .11 Low Flow Threshold for POC 1 : 50 Percent of the 2 Year High Flow Threshold for POC 1: 50 year PREDEVELOPED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat .164 Pervious Total 0.164 Impervious Land Use acre ROADS FLAT 0.286 Impervious Total 0.286 Basin Total 0.45 Element Flows To: Surface Interflow Groundwater MITIGATBD LAND USE Name : RAINGARDEN BASINr Bypass: No GroundWater: No ASBUILT Pervious Land Use acre C, Lawn, Flat .164 Pervious Total 0.164 Impervious Land Use acre ROADS FLAT 0.286 Impervious Total 0.286 Basin Total 0.45 Element Flows To: Surface Interflow Groundwater Surface SMALL RG Surface SMALL R�, Name . Bottom Length: 8 .23 = Bottom Width: 8.23 ft Material thickness of ��; lor�� : Material type for first layer: SMMW: Material thickness of second layer: Material type for second layer: S[�1�: Material thickness of third layer: � Material type for third layer: GRAv� Infiltration On Infiltration rate: 0.4 �nfiltration safety factor: 1 = 53.578 AC-F Wetted surface area On Total volume Infiltrated (ac-ft.} : 18.531 31.68% + 55.: Total Volume Through Riser (ac-ft.) : 4 .924 �� no� , n,o- Total Volume Through Facility (ac-ft.) : 58.502 Percent Infiltrated: 31.68 Total Precip Applied to Facility: 0.859 Total Bvap From Facility: 0.302 Underdrain used Underdrain Diameter (feet) : 0.666666666667 Orifice Diameter (in.) : 8 Offset (in.) : 4 Flow Through Underdrain (ac-ft.) : 35.047 Total Outflow (ac-ft.) : 58 .502 Percent Through Underdrain: 59.91 Discharge Structure Riser Height: 1 ft. Riser Diameter: 24 in. Element Flows To: Outlet 1 Outlet 2 ASBUILT i � _ 1 SMALL RG Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Diecharge(cfs) Infilt(cfa) 0. 0000 0 .0053 0 .0000 0 .0000 0.0000 0. 0440 0 .0052 0 .0000 0 .0000 0.0000 0.0879 0 .0051 0.0001 0.0000 0 .0000 0.1319 0 .0051 0 .0001 0.0000 0 .0000 0.1758 0 .0050 0.0001 0.0000 0 .0000 0.2198 0 .0049 0.0001 0.0000 0 .0000 0.2637 0.0048 0.0002 0.0000 0 .0000 0.3077 0. 0048 0.0002 0.0001 0 .0001 0.3516 0. 0047 0.0002 0.0001 0 .0001 0 .3956 0. 0046 0.0003 0 .0002 0 .0002 0 .4396 0. 0045 0.0003 0 .0002 0 .0002 0 .4835 0. 0045 0.0004 0 .0002 0 .0002 0 .5275 0. 0044 0.0004 0 .0003 0 .0003 0 .5714 0.0043 0.0004 0.0005 0 .0005 0 .6154 0.0043 0.0005 0.0005 0.0005 0 .6593 0.0042 0.0005 0.0007 0.0007 0.7033 0.0041 0.0006 0.00�8 0.0008 0.7473 0.0041 0.0006 0.0010 0.0010 0.7912 0.0040 0.0006 0.0011 0.0011 0.8352 0.0039 0.0007 0.0011 0.0011 0.8791 0.0038 0.0007 0.0011 0.0011 0.9231 0.0038 0.0008 0.0011 0.0011 0.9670 0 .0037 0.0008 0 .0012 0.0012 1.0110 0 .0036 0.0009 0 .0012 0.0012 1.0549 0 .0036 0.0009 0 .0012 0.0012 1.0989 0 .0035 0.0010 0.0012 0.0012 1.1429 0 .0034 0.0010 0 .0013 0.0013 1.1868 0 .0034 0.0011 0.0013 0.0013 1.2308 0 .0033 0.0012 0.0013 0.0013 ' 1.2747 0 .0032 0.0012 0.0013 0.0013 ' 1.3187 0 .0032 0.0013 0.0014 0.0014 1.3626 0 .0031 0.0013 0.0014 0.0014 '� 1.4066 0 .0030 0.0014 0.0014 0.0014 1.4505 0 .0030 0.0015 0.0014 0.0014 1.4945 0 .0029 0.0015 0.0014 0.0014 1.5385 0 .0029 0.0016 0.0014 0.0014 1.5824 0 .0028 0.0016 0.0014 0.0014 1.6264 0.0027 0.0017 0.0014 0.0014 1.6703 0.0027 0.0018 0.0014 0.0014 1.7143 0.0026 0.0019 0.0014 0.0014 1.7582 0.0025 0.0019 0.0014 0.0014 1.8022 0 .0025 0.0020 0.0014 0.0014 1.8462 0 .0024 0.0021 0.0014 0 .0014 1.8901 0.0024 0.0022 0.0017 0 .0017 1.9341 0.0023 0.0022 0.0017 0 .0017 1.9780 0.0022 0.0023 0.0017 0 .0017 2 .0220 0.0022 0.0024 0.0017 0 .0017 2 .0659 0 .0021 0.0025 0.0017 0 .0017 2 .1099 0 .0021 0.0026 0.0017 0 .0017 2 .1538 0 .0020 0.0027 0.0017 0 .0017 2 .1978 0 .0020 0.0027 0.0017 0 .0017 2 .2418 0 .0019 0.0028 0.0017 0 .0017 2 .2857 0 .0018 0.0029 0.0017 0 . 0017 ASBUILT 2 .3297 0 . 0018 0.0030 0 . 0017 0 . 0017 2 .3736 0.0017 0.0031 0. 0017 0. 0017 2.4176 0.0017 0.0032 0.0017 0.0017 2.4615 0 .0016 0.0033 0.0017 0.0017 2 .5000 0 .0016 0.0034 0.0021 0 .0021 Surface SMALL RG Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Diacharge(cfs) To Ameaded(cfa) Wetted Surface 2 .5000 0.0053 0.0034 0 .0000 0.0097 0 .0000 2 .5440 0.0054 0.0036 0 .0000 0.0097 0 .0001 2 .5879 0.0054 0.0038 0.0000 0.0100 0 .0001 2 .6319 0.0055 0.0041 0.0000 0 . 0102 0 .0001 2.6758 0.0056 0.0043 0.0000 0. 0105 0 .0002 2 .7198 0.0057 0.0046 0.0000 0. 0108 0 .0002 2 .7637 0.0057 0 .0048 0.0000 0.0111 0 .0002 2 .8077 0 .0058 0 .0051 0.0000 0.0113 0.0002 2 .8516 0 .0059 0.0053 0.0000 0.0116 0.0003 2.8956 0 .0060 0.0056 0 .0000 0.0119 0.0003 2.9396 0 .0060 0.0059 0 .0000 0 .0122 0.0003 2.9835 0 .0061 0.0061 0 .0000 0.0124 0.0004 3 .0275 0.0062 0.0064 0 .0000 0.0127 0.0004 '�I 3 .0714 0.0063 0.0067 0 .0000 0.0130 0.0004 3 .1154 0.0064 0.0069 0 .0000 0.0133 0.0005 I 3 .1593 0.0064 0.0072 0 .0000 0 .0135 0.0005 I 3 .2033 0.0065 0.0075 0.0000 0 .0138 0.0005 I 3 .2473 0.0066 0.0078 0 . 0000 0.0141 0.0006 �� 3 .2912 0 .0067 0.0081 0. 0000 0.0144 0 .0006 � 3 .3352 0 .0068 0.0084 0. 0000 0.0146 0 .0006 3 .3791 0 .0069 0.0087 0. 0000 0.0149 0 .0007 3 .4231 0 .0069 0.0090 0.0000 0.0152 0 .0007 3 .4670 0 .0070 0 .0093 0.0000 0.0155 0 .0007 I 3 .5110 0 .0071 0 .0096 0.0000 0.0157 0 .0008 3 .5549 0 .0072 0 .0099 0.0000 0.0160 0.0008 3 .5989 0. 0073 0 .0102 0.0000 0.0163 0.0008 3 .6429 0. 0074 0.0106 0.0000 0.0166 0.0009 3 .6868 0. 0074 0.0109 0.0000 0.0169 0 .0009 3 .7308 0.0075 0.0112 0.0000 0.0171 0 .0009 3 .7747 0.0076 0.0116 0.0000 0.0174 0 .0010 3 .8187 0.0077 0.0119 0 .0000 0.0177 0 .0010 3 .8626 0.0078 0.0122 0 .0000 0.0180 0 .0010 3 .9066 0.0079 0.0126 0 .0075 0 .0182 0.0011 3 .9505 0 .0080 0.0129 0 .0090 0 .0185 0.0011 3 .9945 0 .0080 0.0133 0.0092 0 .0188 0.0011 4.0000 0.0081 0.0133 0.0108 0 .0188 0.0004 Name : Surface SMALL RG Element Flows To: Outlet 1 Outlet 2 SMALL RG ANALYSIS R$SULTS ASBUILT Stream Protection Duration Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.164 Total Impervious Area:0.286 Mitigated Landuse Totals for POC #1 Total Pervious Area:0.164 Total Impervious Area:0.286 Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.119654 5 year 0.155502 10 year 0.180398 25 year 0.213252 50 year 0.23878 100 year 0.265239 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.107609 5 year 0 .148789 10 year 0 .177521 25 year 0.21548 50 year 0.24496 100 year 0.275473 Stream Protection Duration Annual Peake for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0 .165 �. 158 1950 0.156 0.158 1951 0.103 0.102 1952 0.080 0 .078 1953 0.087 0 .083 1954 0.098 0 .091 1955 0.108 0 .108 1956 0.107 0.105 1957 0.128 0.128 1958 0 .096 0.071 1959 0.092 0.068 1960 0.107 0.105 1961 0.107 0.106 1962 0.087 0.064 1963 0 .104 0. 087 ! 1964 0 .097 �. 081 1965 0 .133 �. 108 ' 1966 0 .083 �. 082 1967 0 .149 0. 152 1968 0.166 0.134 � ASBUILT 1969 0 .121 0.123 1970 0.112 0.110 1971 0.133 0.115 1972 0.151 0.140 1973 0.076 0.072 1974 0 .125 0.092 1975 0 .129 0.128 1976 0.097 0.095 1977 0.093 0.075 1978 0. 118 0.119 1979 0. 158 0.067 1980 0.172 0.182 1981 0.123 0.123 1982 0.182 0.184 1983 0.137 0.140 1984 0.090 0.069 1985 0.124 0.125 1986 0.104 0.103 1987 0. 157 0.108 1988 0 .092 0.085 1989 0.115 0.050 1990 0.256 0.263 1991 0 .194 0. 192 1992 0 .089 0.089 1993 0 .074 0.060 1994 0 .077 0.055 1995 0 .108 0.103 1996 0. 127 0.133 1997 0.120 0.119 1998 0.111 0.090 1999 0 .249 0.241 2000 0.120 0.118 2001 0.122 0.109 2002 0 .163 0.166 2003 0 .127 0.058 2004 0 .231 0.234 2005 0.106 0.107 2006 0.096 0.094 2007 0.229 0.218 2008 0.190 0.184 2009 0.141 0.124 Stream Protection Duration Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0 .2560 0.2635 2 0 .2492 0.2409 3 0 .2306 0.2339 4 0.2290 0.2184 5 0.1937 0.1919 6 0. 1902 0.1844 7 0. 1820 0.183; 8 0.1721 0 .18�� 9 0.1657 0 .1664 10 0.1650 0.1585 11 0.1628 0.15?9 ASBUILT 12 0.1583 0.1523 13 0.1573 0.1402 14 0.1564 �.1397 15 0.1513 0.1336 16 0.1487 0.1335 17 0.1414 0 .1283 18 0 .1367 0.1282 19 0 .1335 0.1247 20 0 .1334 0.1237 21 0 .1292 0.1233 22 0 . 1279 0.1232 23 0. 1273 0.1189 24 0. 1266 0. 1188 25 0. 1251 0. 1183 26 0.1239 0.1153 27 0 .1234 0.1103 28 0 .1216 0.1090 29 0 .1212 0.1082 30 0 .1203 0.1081 31 0 .1198 0.1078 32 0 .1175 0.1075 33 0.1154 0.1063 34 0.1118 0.1048 35 0. 1112 0.1045 36 0.1084 0.1031 37 0.1080 �. 1029 38 0.1073 0. 1022 39 0.1070 0.0953 40 0.1065 0.0942 41 0 .1060 0 .0924 42 0 .1040 0 .0913 43 0 .1039 0 .0896 ' 44 0 .1026 0 .0890 45 0 .0975 0 .0866 46 0 .0967 0.0852 47 0. 0967 0.0834 48 0. 0964 0.0820 49 0. 0959 0.0806 50 0. 0930 0.0778 51 0.0925 0.0754 52 0.0923 0.0723 53 0.0902 0. 0714 54 0 .0894 0.0687 55 0 .0870 0. 0683 56 0 .0868 0. 0673 57 0 .0831 0. 0642 58 0.0803 0.0596 59 0.0770 0.0579 60 0.0758 0.0553 61 0.0743 0.0500 Stream Protection Duration POC #1 Facilitv duration standard for 1+ flows . ASBUILT Flow(cfs) Predev Mit Percentage Pass/Fail 0 .0598 1656 1069 64 Pass 0 .0616 1498 980 65 Pass 0.0634 1336 888 66 Pass 0.0652 1197 813 67 Pass 0.0671 1080 747 69 Pass 0. 0689 985 689 69 Pass 0. 0707 898 636 70 Pass 0.0725 807 586 72 Pass 0.0743 743 553 74 Pass 0.0761 680 504 74 Pass 0 .0779 630 472 74 Pass 0.0797 574 434 75 Pass 0.0815 537 414 77 Pass 0.0833 497 379 76 Pass 0.0851 450 348 77 Pass 0.0869 420 321 76 Pass 0 .0887 392 296 75 Pass 0 .0906 363 278 76 Pass 0 .0924 340 253 74 Pass 0 .0942 320 240 75 Pass 0 .0960 298 227 76 Pass 0 .0978 277 214 77 Pass 0.0996 254 198 77 Pass 0.1014 234 188 80 Pass 0.1032 219 178 81 Pass 0.1050 205 169 82 Pas� 0.1068 194 157 80 Pa�� 0.1086 178 147 82 Pa�. `- 0. 1104 169 135 79 Pa�: 0. 1122 158 128 81 Pa�:. 0 . 1141 149 125 83 Pa� ' 0. 1159 136 117 86 Pa:- 0. 1177 130 108 83 Pa: - 0. 1195 120 99 82 Pa� � 0. 1213 109 97 88 Pa= ` 0. 1231 106 94 88 Pa:= 0. 1249 102 89 87 Pa� 0. 1267 97 86 88 Pa: 0. 1285 90 83 92 Pa: 0.1303 82 78 95 Pa: 0.1321 82 77 93 PG: ' 0.1339 77 72 93 Pa: --- 0.1357 76 68 89 Pas� 0.1376 73 63 86 Pass 0.1394 67 58 86 Pass ' 0.1412 65 55 84 Pass 0.1430 61 53 86 Pass 0.1448 59 51 86 Pass 0 .1466 58 49 84 Pass 0 .1484 55 45 81 Pass 0 .1502 49 45 91 Pass � 0 .1520 47 42 89 Pass � 0 .1538 44 38 86 Pass 0 .1556 40 37 92 Pass 0 .1574 37 36 97 Pass 0 .1592 35 32 91 Pass ASBUILT - 0.1611 32 29 90 Pass 0.1629 31 27 87 Pass 0.1647 30 26 86 Pass 0.1665 26 26 100 Pass 0.1683 25 23 92 Pass 0.1701 22 23 104 Pass 0.1719 22 23 104 Pass 0.1737 21 23 109 Pass 0.1755 20 20 100 Pass 0.1773 20 18 90 Pass 0.1791 17 16 94 Pass 0.1809 17 15 88 Pass 0.1827 14 14 100 Pass 0.1846 13 11 84 Pass 0 .1864 13 11 84 Pass 0 .1882 12 9 75 Pass 0 .1900 11 9 81 Pass 0 .1918 10 9 90 Pass 0 .1936 9 8 88 Pass 0 .1954 8 8 100 Pass 0 .1972 8 8 100 Pass 0 .1990 8 8 100 Pass 0 .2008 8 8 100 Pass 0 .2026 8 8 100 Pass 0 .2044 7 7 100 Pass 0 .2062 7 7 100 Pass 0 .2081 7 7 100 Pass 0 .2099 7 7 100 Pass 0 .2117 7 7 100 Pass 0 .2135 7 7 100 Pass 0 .2153 7 6 85 Pass 0 .2171 7 6 85 Pass 0 .2189 6 5 83 Pass 0 .2207 5 5 100 Pass 0 .2225 5 5 100 Pass 0 .2243 5 4 80 Pass 0 .2261 5 4 80 Pass 0 .2279 5 4 80 Pass 0 .2297 3 4 133 Fail 0 .2315 2 4 200 Fail 0 .2334 2 4 200 Fail 0 .2352 2 3 150 Fail 0 .2370 2 3 150 Fail 0 .2388 2 3 150 Fail The development has an increase in flow duratione from 1/2 Predeveloped 2 year flow to the 2 year flow or more than a 10� increase from the 2 year to the 50 year flow. Water Quality SMP Flow and Volume for POC #1 on-line facility volume: D acre-feet On-liae facility target flow: 0 cfe. Adjusted for 15 min: 0 cfa. Off-line facility target flow: 0 cfa. Adjusted for 15 min: 0 cfa. ASBUILT LID Report LID Technique Used for Total Volumn Volumn Infiltration Cumulative Percent Water Quality Percent Comment Treatment? Needs Through Volumn Volumn Volumn Water Quality Treatment Facility (ac-ft.) Infiltration Infiltrated Treated (ac-ft) (ac-ft) Credit SMALL RG POC N 53.24 N 31.68 Total Volume Infiltrated 53.24 0.00 0.00 31.68 0.00 0� No Treat. Credit Compliance with LID Standard e Duration Analysis Result = Passed Perind and Impind Changes No changes have been made. This program and accompanying documentation are provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright �� by : Clear Creek Solutions, Inc. 2005-2016; All Rights Reserved. � i1 ;'� I �, , � AS B U I LT � ---- ----- — -- - --- ----------- -- — --__ — --- Worksheet for Swale Project Description Friction Method Manning Formula - y — -' Solve For Discharge �� 2� Input Data Roughness Coefficient 0.027 QOUGN�LI' ��3 crr 5�7 u Channel Siope 0 00660 fUft t-L oLv 5 -n.y.�2.o vt.�t S w �� Normal Depth �s� �� F�� K o��%' —�0.5o ft L 5 YR- �S w+►N Ps�+�c F"z� Left Side Slope 2.00 ft/ft(H:� �!vTv �Nc� � �,�Z C�S. Right Side Slope 2.00 ft/ft(H:� i R 7 _^_.f"=5 ! - C�,(� � c�-> Results _� Discharge 0.82 ft'!s � �-�� ' '-=�~ ' Flow Area o.so ft= 2 S r�2 �v�,�,-r-- w 1�-�— Wetted Perimeter 224 ft �. HydraulicRadius 0.22 ft r�� w �{ �b�C Top Width 2.00 ft ��'�� F�EE c3C r4-�'�iP. Critical Depth 0.40 ft Critical Slope 0 02103 ft!ft Velocity 1.65 ft/s Velocity Head 0.04 f� Specific Energy 0.54 ft Froude Number Flow Type Subcrit GVF Input Data Downstream Depth 0 0� Length 0 Number Of Steps GVF Output Data Upstream Depth �- � Profile Description Profile Headloss - Downstream Velocity Infinity • , Upstream Velocity Infinity rt s Normal Depth 0.5D ft Critical Depth 0.40 ft Channel Slope 0.00660 ftift Crt cal Slope 0 02103 ftr8 Bentley Systems Inc. Haestad Methods SoliB�rtl�}eFlowMaster VBi ISELECTseries 1� [08 11.01 03) 1130/2014 12:52:43 PM 27 Siemons Company Dri�e�0��rT��95 USA +1-203-755-1666 Page t of 1 FOR ASBUILT - -------------------— -- _ __ __ -- - ---- --— -- -_ _- - _ _ ----------- Worksheet for Swale 100yr Pro�ect Description Friction Method Manning Formula _ -� + �r Solve For Normal Depth ! � Input Data Roughness Ccefficient OA27 �p�G��-Y �3 �F s eR% Channel Slope 0.00660 ft/ft ��S ?'�Rm�GH Sw�� . Left Side Slope 2.00 ft/ft(H:� �DO �'2 IS M1N t��i4K ��--�" ` Right Side Slope 2.00 ft/ft(H:� �,�� ND = 2•�a0 �} Oischarge 0 86 ft'!s - - _ � , ,r f,t � ,•'_- � 'r , Results Normal Depth 0 51 ft � v i ii±:Y -` ;` ` ' Flow Area 0.52 ft2 v V 6� '�' � 4 ' � . �' Wetted Perimeter Z,Z� ft �vE^�T- Hydraulic Radius 0.23 ft Top Width 2.03 ft Critical Depth 0.41 ft Critical Slope 0.02091 fUft Velocity 1.67 ft/s Velocity Head 0.04 ft i Specific Energy 0.55 R Froude Number 0.58 Flow Type Subcritical GVF fnput Data Downstream Depth 0.00 ft Length 0.00 ft Number Of Steps � GVF Output Data Upstream Depth 0.00 ft Profile Description Profile Headloss 0.00 ft Downstream Velocity infinity ft/s Upstream Velocity Infinity ft/s Normai Depth 0.51 ft Critical Depth �•41 ft Channel Slope 0.00660 ft!ft Critical Slope 0.02091 ft/ft Bentley Systems,Inc. Haestad Methods SoliB�+tl�FtewMaster V8i(SELECTseries 1) [08.11.01.03) 113012014 1:08:45 PM 27 Siemons Company Dri��i'eT20�1 ��v��95 USA �1-203•755-1666 Page 1 of 1 FOR ASBUILT i - � i VANTAGE GLEN-TRENCH DRAIN 1000-RAINGARDEN#2-25-year-ASBUILT - � _ .r ��.� ._. , . �,_� _,�. ._ ._Mv� RUNOFF CALCULATIONS(RATIONAL METHOD) -- _ __�._ _�.�,. — AREA C AREA(SF) Area(AC) (Area(AC)"C) Total Area(ACJ Composite C r . .._ _, GRASS d.25 -~T� 7.144' O.i64 OA4 t�.�YSQ 0.66 ' PAVEMENT Q.4Q 12,458 0.286 0.26 T�= 6.3 (MIN) MinimumTc 25 Year Storm PR= 3.� 24-hr Rainfall Depth Renton aR= 2.66 25 year bR= 0.650 25 year iR= 0.80 Eq 3-4 IR= 2.73 (IN/HR) Eq 3-3 Flow(Rational)_, !}�?;(CFS) Eq 3-1 \\SEA13\civil\113001-113250\113188(Vantage Glen)\PROIECT DOCUMENTS\Storm Drainage\DetConv Calcs\CONV(ASBUIIT)\TR-1000- RG-2 25yr_ASBUILT.xlsx VANTAGE GLEN -TRENCH DRAIN 1000-RAINGARDEN#2-100-year-ASBUILT . :_ _,_ __ _: _:.__ �_.�-� RUNOfF CALCULATIONS(RATIONAL METHOD) -- _�___.�_ AREA � C AREA(SF) Area(AC) (Area(AC)"C) � Total Area(AC) Composite G GRASS 0.25 7,144 0.164 0.04 0.450 0.66 PAVEMENT 0,90 12,458 0.286 0.26 T�= 6.3 (MIN) Minimum Tc 100 YearStorm PR= 3.9 24-hr Rainfall Depth Renton aR= 2.61 100 year bR= 0.630 100 year iR= 0.82 Eq 3-4 IR= 3.19 (IN/HR) Eq 3-3 Flow(Rational)= 0.95 (CFS) Eq 3-1 ' � � � I � � I � `_ .� I i � I ; -y ': � : �i i , -� I \\SEA13\civil\113001-113250\113188(Vantage Glen�\PROJECT�OCUMENTS\Storm Drainage\DetConv Calcs\CONV(ASBUILT)\TR-1000- RG-2 100yr_ASBUI LT.xlsx Z886-H� Spec 02630 2.01.B.1.c SPECIFICATION SHEET Z�RN� 6-3/4 [171j WIDE REVEAL TRENCH DRAIN SYSTEM TAG WITH HEAVY-DUTY FRAMEASSEMBLY t�imensiona�Oata(inches ar,d[mm]?are SuSject to Manufacturing Tolerances and Change Without Notice �?E�1=Yt"i= E�:Gi'vtc= !� =c�c- - ,E ��R CuF.CPETF ErvCPSE"1Ei.T . �rSFOP�_Irar. _ $ASE� J°0'i A?PUCA7IOFJ Ar,� LJCA! CG'_,ES �` `+ s� �` -___ .. � . ir C� "7�•�� .4L� �.�•"u' '�-� i 1 �r - --" - - b i ��7�: SO z = '� � ` `` �s� - s� , .. � �,; (;O1_ ___ � - l' ---J � � � p_ � ., - '_ .. - . _ . _.__ .... _-UL� lLL':�L� _ f.- - E�- '--1 ' � �.{,�_ .`, =�- - =��--��_ � - 5 � �� ` -T � ��--N--��. - Y -- - �r----�r��^�, �y ::L_- ;•^,^. � � - _. �,�.�, NOTE:+ACtual Channel kngth is 81 1/4(2064]to allow for overiap. ENGINEERlNG SPECIFICATIaN:Zum Z886-HO Channeis are 80 (2032J long, 6-3/4[171�wide reveal and have a 4 [102]throat. Modular channel sections are made of 0% water absorbent High Oensiry Pofyethylene(HDPE).Channels have a positive mechanicai connedion between channel sections that wiii not separate during the installation and mechanicalty lodc into the concrete surround every 10[254].Channels weigh less than 2.31 tbs.[1.05kg]per tinearfoot,have a smooth, 1-1/2[38] radiused self Geaning bottom with a Manning's ccefficient of.009 and.75%or neutral 0%built in slope.Channels have rebar dips standard to secure trench in its final location. Channels provided with standard DGC grates that lodc down to frame.Zum 5.375(137J wide reveal Ductile Iron Slotted Grate conforming to ASTM specifica6on A536-84,Grade 80-55-06. Ductile Iron g�ate is rated dass C per the DIN EN1433 top bad Gassfica6ons. Supplied in 20[508]nominal lengths with 1/2�13]wide slots,and 3/4[19)bearing depth.Grate has an open area of 28.1 sq.in per fl.[59,463 sq.mm per meterJ. The .105 (2.67J thidc Heavy-Duty Carbon Steel Frame Assembty confortns to RSTM speafica6on A36 with 1D- 4 [102] long concxete anchors per 80[2032]. Grate lodcdown bars are to be integral to the frame. Frame supplied with powder ooated finish.All welds must be perfomied by a certified welder per ASTM standard AWS D1.1. Frames produced in the U.S.A. �2 S�x-foot Eight-m�H�gh Density?akyethylene(HDPE)' i Trench 'A' i 'B' Flow No. Shallow Inv ; Oeep inv. , (cfs) (gpm) (Ips) suFFoc oFrto�s tc,nedvsve�ry a�e o�i ssoi 3.50(89J � a.�o��oa� ; 0 2� s3 � a�� ' 8602 4.10 j104J ; 4.7C(119j I 0.27 122 8 ��1 Closed End Cap _ •U2 2(51j No-Hub Bottom Outlet 8603 4.70[119J :, 5.3G,135) ; 0.34 152 10 _-F2 2(51j No-liub End Outlet _ -U3 3(76j No-Hub Bottom Outlet 8603N 5.30[135J ; 5.30(135) ! - - - _-E3 3 R6J No-Hub End Outlet _ -Ua a 102 No-Hub Bottom Outlei g604 5.30[235J . 5 90[150J '; 0.41 183 ` 12 --E4 4 j102�No-Hub End Outlet •U6 6�152�N�tiub Bottom Outlet g605 5.90 150 ; 6.50 165 0.48 214 13 -E6 E�152 NoHub End Outlet 0.97 CFS > 6 , [1 5, : 1 [1 D ; . . 45 1 � -� BlackAad Resisbnt Coated To frame �.82 CF$ ✓ ! 7.10(180] � 7.10[180] ':, - - - - p 8607 .10(180J 7.70(196J ; 0.62 276 17 -�D Light Duty Grates on Hea Duty frame -SW Sidewall E�ension-9[229j High 7. 211 � 8 1 _-SW2 SidavaA Extension•1 B[457j High 8609 ; 8 30[21 8.90(226] � 0.76 � 339 21 Grate OpOor�s(load CiassificaDons are per DIN ENt433) � 8610 8.90(226J ' - {241 J � 0.83 371 23 bDC Black Apd Resiscant Epo�ry Coated Ductile Grete-Class C ' 8 �� ' 9�5�I241 j ' 10.10 0.90 403 25 -BDE Bladc kdd Resistant Epozy Coated DucUte Grate-Class E -� ' 8612 10.10[257J t O70[27 0.97 435 27 -BG GaNan¢ed Dudile Iron Bar Grate•CIasS C i 8612N 10_70[272j i 0.70(272J I - - - _-DBG DucUle Iron Cast Bar Grate-Gass C � 8613 10. 0[272] , ?1.30[287j 1.04 46 29 _•DC DucDle I+on Sohd Cover-Class C I 8614 11.30(287) ; 11.9fl(302) I 1 11 498 31 _-DGC Ductile Iron Slotted Grate-Class C' g615 11.90[302] 1 12.50[318] 1.18 530 � 33 -DGE Dur,�le Iron Slotted Grate-Class E -GDC Galvan¢ed Duc61e Iron Stotted Grate-Class C _-GDE Galvanized Du�tile Iron Slotted Grate-Class E _-GHPD GaNan¢ed Heel-Proof Duc��le Grate-Class B �� _-GHPDE Galvan¢ed Heel-Proof Ductile Grate-Class E a a es�stant xy oat u e ra e- ass � -HPO Heel-Proof Ouctile Slotted Gra1e-Class B -_pV v_�Sc Ductile Iron Slotted Grate-Ctass C �-HPDE Hee1-Procf Duaile Slotted Grate-Class E -.��_�� Ductile Iron Siotted Grate-Class E ' _-RFGC Reinforced Slotted Galvanized Grate-Class C -�pr,rUSA Galvan¢ed Duai{e Slotted Grate-Class C _-RFSC Reinfwced Sbtted Stainless Steel Grate-Class C -.�pE_USA Gafvan¢ed Ductite SVotted Grate-Class E _�PGC Reinforced Perforated Galvanized Grate-Class C -�HppE_US�, Galvani¢ed Hee{-Proof Ductiie Grate-Class E ! -RPGRC Reinforced Pertorated Gahran¢ed Reverse Punch Grate-Gass C -_HPDE-USA He�-Proof Ducdle Sbtted Grate-Class E _-RPSC Reinforced Perforated Stainless Steel Grate-Class C -.pp� Plastic Perfaated Grale-C4ass _-RPSRC Reirtforced Perforated Stainless Steel Reverse Punch Grete-Class C - Msceiarieots0�dons �� _-`JP 'v'andal-Proot LoCkoowr --DB 2c±c!*�D�Te 5t*�nc• -.s� Jomt ConneGor Deco►ative Gr�te Optior�s(Loed qass�ations are per DIN EN��B U I LT _SBG Stamless Stee1 Bar Grate-Class E REV. D DATE: 01/31/13 C.N. NO. 124330 'REvu�R�:v FURr+!S^'c C Uh�ESS G?HE��ti`SE SPECiF:ED PRODJDWG.NO. Z886-HD ZURN INDUSTRIES,LLC • SPECIFICATION DRAINAGE OPERATION• 1801 Pittsburgh Ave. • Erie,PA 16514 Phone: 814W55-0921 ♦ Fax: 814'd54-7929 ♦ Wor1d Wide Web: wwwzum.com In Canada: ZURN INDUSTRIES LIMITED • 3544 Nashua Drive • M;ssfssauga. Ontano L4V1L2 • Pfione: 405�405-8272 Fax: 905,405-1292 [_ASBU L VANTAGE POINT-BACKWATER CALCULATIONS-TRUNK 300,Trench Drain-3000,and CB-56-CB-38 (il (3) (41 (sl (s) (e> (>>) l��) (�8) l�el (�o> l��l (4�1 laz� � �as> � r-.,� �4�� , (so) (si> (ss) (ssl (s�) Po) (�i� pzn� _ (�s� ps) (��) DESIGN INC MANNINGS MANNINGS HEAD APPR YEAR JUNCT FULLFLOW CATCH FULLFLOW CAP VEL CRIT ATCRIT TAIL FRICT ENTR EXIT OUT IN VEL BEND IUNCT HEAD OVERTOP STORM STRUCTURE RIM DIAM INVERT ANGL n L 5 FLOW V PVMT GRA55 AREA TOTALTC FLOW CAPACITV CHECK VEL HEAD DEPTH DEPTH WATER LOSS LOSS LOSS CTRL CTRL HEAD LOSS LOSS WATER CHECK Notes UP DOWN UP DOWN UP DOWN UP UP UP UP UP UP DOWN UP DOWN UP UP UP UP UP . � (YEAR)}---- (ltl (Nl fF'j 1='j iJN;� fFTi ;F I IDEG) �FT) T _% _ (CFS) ._.._ IFPS) (AC) IAC) lA�l (MIN) (CFS (CFS) _T_(FPS)---(FT) �FT)_T�FT� IFTj �FT) (FT)-�(FT�-_ _-,_IFT) _ (FT) �FT�- (FT) (FT�_-,..-(FT) ----- ..... ..... . .. � -�- - 25 � CB 106 ��. CB-105 354.10 383.97 12 382.65 382.52 84 40 0.012 27 ( 0.4876 0.00 3.41 �0.021 �0.0�3 O.D24 5.00 , 0.06 ' 2.68 OK ' 0.08 ! 0.�010 i 0.13 383.52 0.00 i 0.00 i 0.00 s 383.65 382.78� O.OD �O.00T 0.00 '383.65, OK � Does not overtop __._ _..._... _. _ _.. _._ _._�_ --.. �_._ .-_+- .. _- ---�'---i---h_ .-_-�-�-�- _ - -- . ---- �-- ; -- -�------_ .__ . . 25 CB 105 �� CB 104 383.97 383.93 12 38252 381.95 0 DO : 0.012 127 � 0 45:G 0 00 � 3Z9 ; 0.045 0.006 0.051 5.00 , 0.19 : 2.59 ' OK 0.24 ��; 0.00 � 0.18 0.24 382.95 0.00 ; 0.00 '�, O.OD�383.52 382J6�_0.00 0.00+_0 00 ;383.52'��,_OK Dces not overtop � ----- -_ _ _ ._. __ _.__ �. ._.--� . _ . .T___.. .----� --- _._ _. _. _- --' ��.. . . 25 CB 104 �� CB-103 383.93 383.66 12 381.95 381.61 D 00 �' 0.012 72 ' 0.47M 0.00 3 38 '; 0.045 0.011 OA56 5.00 032 ''��, 2.65 ; OK 0.41 'i 0.00 : 0.23 032 .382.61 0.00 ; 0.00 '� 0 00 ;382.95 382 27��. 0.00 �� 0.00 ; 0 00 '�382.95�''��, OK Dces not overtop � . .._._ ._ .__. ...._ ._._� .._._ . . _---- -- ',-�-- - ��-�----- ----_ _.__ -. ._.. � -_-- -'---- �- -'----�--- . . 25 CB 103 '�. CB 102 383.66 383.52 12 381.6? 38L57 27J0 0.012 21 0.19% 0 00 2 14 � 0 020 0.000 . 0.020 5.00 038 '�, 1.68 I OK 0.48 ; 0.00 �. OZS 0.34 ��:382.58. 0.00 �� 0.00 �� 0 00 ;382.62 38195 0.00 ''��, 0 00 ':, 0.00 '�.382.61�''��, OK � Dces not overtop . ..._ _. _ -- -- .._.__ .___ .__ --* --._ __... _ --- � --�-------�--- .� ..__-_-�•_ ____---`-- --.._. •___._._- _•__ .�..-.�_ ' '--� 25 CB 102 '�. CB 101 38352 38537 12 381.57 38137 2230 ', 0.012 83 0.247G 0.00 i . 2.41 0 066 ��, 0.012 0.078 5.00 0.57 ; 1.89 �I OK OJ2 0.�_0_31 0.43 '�.�_382.26ti 0.02 ! D_00 ; 0 01 ;382.58. 382.00 __0.00 ��, 0.00 i. 0.00 ��382.58�. OK Dces not overtop � .__ .. _._ ,_ .._ .___ _.__.__�.-.__ __._ . _--- �� - -----*- --- - _t- : . .... - - +-----j- - - - -'- - - ' '' '' � ' � �-----..�.-------- -. .. ---_-..--.__ ... . . _.. �-- -!- �---.--�.._---�- �-�-------- '.- I ' � � �a � : 0.01 �; 0.01 0.00 �'�.382.26�, OK Dces not wertop 25 � CB-100 ! RAINGARDEN 384.84�380.26: 12 380.78��380.26. D.00 ''� 0.012 i 97 . 0.54%� 0.00 '�: 3.6p I 0.028 '��, 0.025 �'� 0.053 ' S.00 '�, 1.03 � 2.83 : 0.03 D.43 0. 9 �'��381.40 0.01 7 '�. 0.01 �'� . i . � __25-t CB 101 _ C8 100 38537 380.84µ 12 _381.22 380_80-91 2�12 48 0.88% 0.00 4.60 ' 0 123 0.039_0.162- 5.00 �, 0.94 3.61 ON i.32 0.02 0.41 0.56 381.80 0.03 0.01 0 03 ,381.82'�.38138 j 0.02�_��, 0.00 0.00 i 381.80 OK Dces not overtop : � f' ----- . i : � ,. �. .. �..- --- � . �. -- i '. : � � I , .. . � .. . _.. ---'- .__ . . ___ �-- - _.- -__.--- ' _.. ----��. . , ---- - . -t .__ ._ . �, . _ __._ ._ . -._ _ � --- _. , � 1- , , --}-- _ ' _.__� �_ +-____- - -- - � '-_ _ -- ---- -'- ---, - - -1 - -- - --.- �. _ ----__ 100 �. CB 166�_ C8 105 384.1D 383.97 12 382.65 382.52 8440 ; 0012 27 0.48% 000 3.41 '� 0.021 `0.003 0.024 5.00 0.�_ 2.66 � OK ��j 0.10 '�.�0.00 j D.11� 0.15 383.52 0.00 ��. 0.00 ��. D.00 383.65 382.80 0.00�� 0.00 i 0.00 353.65'��_ OK � Dcesnotovertop �-- �--- - -.. .Y._ ._.----' ..._ _.,-----�--- __._ .__---'-- - - ---.-.t- � �--- �� 100 '� C8 105_ _', CB 104 383.97 383.93 12 382.52 381.95 0.00 ' 0012�_127�0.45% 000 3.29 �i 0.005 � 0.006 0.051 S.DO 0.24 j 2.59 OK �', 030 ��, 0.00 � 0.20 ; 0.27 382.95 0.00�0.00 �. 0.00 383.52 36279 0.00 '. 0.0 000 353.52' _ OK ' Dcesno[overtop ...._ _.._ -_ ___ _...�. - - � ----_ __. .----- - � - - i � 100 ' CB 104 _. CB 103 383.93 383.66 12 38195 381.61 0 00 : 0 012 72 0.47% 0 00 3.38 ti 0.095 ' 0.011 0.056 5.00 0.41 2.65 OK '�.. 0.52 '��,y_0.00 0.26 : 036 382.62 0.01 0.00 0.00 382.96 382 31 0.00 ��. O.OD 0.00 382.95 OK � Dces not wertop __. '---- _.. __ ._ ..__ .-_---- ---- --'--_. . _ _ . . ._._._ -'_-- �- ' 100 CB 103 . CB 102 383.66 383.52 12 381.61 381.57 27 7� : 0 012 �. 21 0.19% 0.00 2.14 ��, OA20 : 0.000 OA20 5.00 0.48 1.68 OK I 0.61 ' 0.01 0.29 : 039 382.58 0.00 0.00 0.01 382 62�,382 DO', 0.00 '�� 0.00 0.00 382.62 OK '�. Dces not overtop . _ _... ..... . ---- -_. _. �.._. _ _._ ._---- - --.'-_... . --�---�____. .----�-� r---�------'. -.-1 �300 �CB 102 CB 101 383.52 385.37 12 381.57 38137 22 3D _0 012�t _83 0.249L 0.00 �. 2.41 '�, 0.066 0.012 0.078 5.00 � OJ2 1.89 OK '�, 0.91 0.01 035 j 0.48 382.28 0.03 t 0.01 , 0.01 382.59�.382.061 0.01 �,' 0.00 0.00�2.58+ OK '�, Dces not overtop ._._ _ -__ __- .._. . ._ ---�- ---- ----- ..___. . ...-- -- - ._ . _. �--- - --- ------- - - --�� - r-- -------i- : ---------. , -;-----+ ; � __ ' 0.01 � 0.02 0.00�38218� OK ; Dces not wertop � ! I 100 CB 101 CB-100 38537 384 84 12 381.22 380.80 91.20 - 0 012 . 48 0.889G 0.00 ��. 4.60 '��. 0.123 0.039 0.162 5.00 1.19 3.61 K 0.04 0.46 0.64 381.81'� D.0 0.02 . 7 .. _� '�.,_100 .CB 100 .: RAINGARDEN 384.84 380.26�_ 12 380.78�38016. 0.00� D 012 -� _97 0.54X,; 0.00+ 3.60 �0.028 0.025_,0.053 . 5.00 __131 2.83_ �OK �'�, 1.67 0.04 0.48 0.67 '�.381.40 0_ll 0_02 O.D4 ;381.84,381.48'�, 0.09 '�, 0.00 � 0 00 �38L81� OK Dces no[overtop ..__.. __. . .. _ - . _ _ . . .__ . _ .. � --- �. ; � . � �. . �� ,._ . i I `-- -._ __ � __ --t-- ;- --- � _.; ___. _- .--__ _---- - - --- +--- -�-- I i 'i � 25 � TR 1000 RGARDENN2 �380.96 378.79 6 _37912 378J9 000 � O.D12 i_56 0.779G� 000 ; 2.71 - � � _ -. 0.82 0.53 � 4.18 0.27 0.45 OJS '�,379•26 1.02 0.14 i 0.27 !380.69 380.25'��. 0.00 0.00 � 0.00 �380.69 OK Dcesnotovertop ._-�--- �---- - .. ... _..Y _. ,.. ...._ . .- � ---� -- ' I � _ .� , �. , , . ._ �-�---� t ? s { : i . ��. ; , � : . -, . � �. : ' i -_ __ .,_ __-_ .___ .r ___ ' __ .� - 100 � TR 1000 �. RGARDEN p2 380.% 378.79 I 6 �379 22�378J9� 0 00 ; 0.012 '',, 56 0.77%� 0.00 ; 2J3 ! 0.000 0.000 : 0.000 �5.00 ��.. 0.95 0.53 � 4.54 036 0.47 0.85 ''��.379.27� 137 0.18 0.36 i 38119;380.48 0.00 0.00 0.00 38L19 • Does not cause erosion/flooding _ ___ .r___._ 1 ._-- �- . _ �_ -�-- _. __-_ _..._ .. . _.-._._ -_ � � � i � ` '_._____.` ____. -.y-.._,__. _ _-_ I -a---., ''7._ _-_ � ' "-__ ' ' � . � 100 CB-56 CB-38 t378.02;378.90! 12 �372.81 372.48� 0.00 : 0.012 ! 69 0.48%' 0.00 3A0 0.000 D.000 0.000 � 5.00 2.81 2.67 3.58 0.20 0.72 1.05 '��,37334 037 0.10 0.20 374.11'373.99 0.00 0.00 0.00 374.11 j OK Dces not wertop - i I i - f -}-- -} � I ( i ' ..- . ; i : r i f = I , � � � : i . : i �__ . � ' ' -.-_-,'_' __ __.___ � --_-�'_._ ..� I [ I ; ... __ ., ,.. ,,, -- __-�_ . _ - . . , . �. ____ ___._.___ _._..____. -�. ! , , i ' � 1iSEA�3�,civi0�1 3001-11 3250`,113188(Vantage Glen)1PROJECT DOCUMENTS'�.Storm DrainagelDetConv Calcs�CONV(ASBUILT)',Backwater_ASBUILT.xlsm -_ - ASBUIIT�VANTAGE POINT-BACKWATER CALCUTATIONS ROW UPSTREAM ANALYSIS (�) (3) (4) �5) (6) (9) (>i) (�2) (�8) ��9) (Z�) (21) p . ��<->` > .. :._>; _ ..,�:.�_. �_' �: :_�-. (q�� (42) � -'_; (45) -� (47) ` (50) (51) (55) (56) (57) (70) (71) (72A) � (75) (76) (77) DESIGN INC MANNINGS MANNINGS HEAD APPR YEAR JUNCT FULLFLOW CATCH FULLFLOW CAP VEL CRIT ATCRIT TAIL FRICT ENTR EXIT OUT IN VEL BEND IUNCT HEADW OVERTOP . STORM STRUCTURE RIM DIAM INVERT ANGL n L S FLOW V PVMT GRASS AREA TOTALTC FLOW CAPACITY CHECK VEL HEAD DEPTH DEPTH WATER LO55 LOSS LO55 CTRL CTRL HEAD LO55 �055 ATER CHECK Notes UP DOWN UP DOWN UP DOWN UP UP UP UP UP UP DOWN UP DOWN UP UP UP UP UP (YEAR) __. I�l (�) IFTI IFTI_, �IN) �FT)._., IFTI (DEGI__.__.._ (FT)._.._.%_r(CFS) ._. (FPSI`_ (ACI_,_.IAC�- -�AC)_._..(MIN� (CFS) (CFS� (FPS)^ (FT) I�) IFT) (FT) (FT) (FTI (FTI (FT) . IFT) (FTI_.___IFTI_.,_.IFT) , (FT) . � 25 : CB#7376 CB�t7230 388 16.388.15 i 12 384.52:383 26 0.00 ! 0.012 . 34 46 1 3.66X� 0.00 __, 9.40 ; 0.120 : 0.020 j 0.140 5.00 ; 0.35 73S ' OK 0.44 '� 0.00 ; 0.24 033 ,�.27 0.00 0.00 0.00 ;385.52 384.83 0.00 D.DO �, 0.00 385.52 OK �I Does not overtop � � .__ �_____ __ _ __ _.r _, _____ __ . - -- - �--- + _-- � _�____ ______,�_ i 25 CB#7230 CB tt7076 388 15 383 27; 12 383 26:379 69 0.00,0 012 }176 13 i 2.0376+O.OD 7.00 0.086 i 0.000 0.086 5.00 ' 0.58 5.50 OK OJ4 0.01 032 0.43 ,380.67 0.04 0.00 0.01 ;384.27 383.69 0.00 � 0.00 ', 0.00 384.27; OK Does not overtop �-.__. .___ _� _�__ �_ _ _ ____ ---._._ r 25 ! CB#J7076 CB N7059 383 27:.381 71; 12 :379�62�377 66 0.00 0.012 221 93'�. 0.88'�6��, 0.00 4.62 0.213 0.06�_0182 5.00 1.22 3.63 OK 1.56 0.04 '' 0.47 0.65 378J1t 0.22 0.02 ' 0.04 '380.65 38019 0.01 0.00 �0 00 350.67� OK ' Does not overtop _ . .- -....___ .. . . . . ---- -- - '.---�- , -- �--- ---- �: 25 �: CB�7D59 CB N7575 381Ji�.380 36; 12 377b1+376 20: 0.00 0.012 173.00'�: 0.82%�' 0 00 4.A6 0244 0.052 : 0-296 5.00 1.93 3_48 OK 2.46 0.09 , 0.59 0.64 ;37735� 0.43 0.05 0.09 ;378J5 378.51 0.06 . D.00 �: 0.00 378J3 I OK Does not overtop --- --_- . :-_ � �--,------ •--- - -r �- �-- -._. .._. . _�__. _ ��. �' _ . '��, 25 ' CB#7575 CB#8057 �38036.378.89; 12 376 16';374.66-. 0.00 0.012 199 36: OJS%; 0 00 ; 4.26 0.278 0.043 0 321 5.00 2J3 335 OK 3.48 0.19 �'�, OJ3 l 1.04 375.92 1.00 0.09 0.19 '377.44�377.31 0.09 ; D.OD�0.00 377.35 OK * Does not overtop ,,..__w �__ . . . -- --_..� _ ._ ��-_ . -� -T --.__ �T.. --.. ..__ _ ,� _.:. ..._...- - -----E-- . r -__. �� 25 � CB tt8057 CB 38 378 89�378.88��. 12 �374.66 37238��, 0.00 , 0.012 . 19 00 ;12.00%: 0.00 ; 17.02 0.234 � 0.053 0 287 5.00 3.42 13.37 OK . 4.35 0.29 '��, OJ9 ; 1.20 �373.58 0.15 0.15 0.29 ;376.10��.376 02 i 0.19 ! 0.00 i 0.00 �375.92 OK Does not overtop ',___�._ : . . . ...__.�--- ----. ..,----�- __-:---�,- _-'__ ,}___-- �--. ____- ____. __ _ -�-�.�__,.._____..�� _- � __�t �_ ,...-- --�.-- r�.�. ._ ... . �� 25 � CB 38 CB 40 378.88��-377.85 I 12 �37238 372 Ol' 0.00 0.012 ' 48 92 I OJ6%; 0 13 ; 4.27 0 000 � 0.000 0 000 5.00 3.54 336 • C4^51 � 0 32 '�, D.80 ! 1.23 372.91 0.41 � 0.16 032 ,373.85'��373.86�.. 0 29 '�. 0.01 � 0.01 373.58 ON � Does not overtop .....�---... . . ._.. _. .. . __._- �___.__ . . .�,-.._. __..._._� _..--.r._ _,.�.____. �.�..�----+ ._._-�� - ---- - �-��.____.:_�.�� . F --- - � --- � --�-- t � -�- '"__'__ .�__- _.._�. ......._ . ..�i.__ •__._.__._ ._.�-:.----�- . .�___" .?__ _-_Y..____"_.:.. ..._ -- I .+ h-r-� _._ � .__-y.--. Y_ ._._ . 100 CB u7376 CB i17230 38516;388.15; 12 384.52 383Z6' 0 0.012 34.46 ' 3.66% 0.00 ; 9.40 rt 0.120 ' 0.020 0.140 5.00 0.44 738 OK ' 0.56 0.00 � 0.27 ; 037 ',384.25 0.00 ; 0.00 0.00 385.53µ384.88 0.00 i 0.00 0.00 I 385.53 OK Does not overtop _ _�_� __.�_ ,_ +- --_.--- -- -- - -. -- - - - i - � -- ----- 100 CB N723D CB k7076 388 15 I 383.27; 12 383 26'379 69 0 0 012 176 13', 2.03% 0 00 7.00 I 0 086 ; 0.000 0 086 5.00 OJ3 S.SO :, OK 0.94 i 0.01 0.36 � 0.49 '',380J0 0.06 0.01 0.01 384.28;383J5 0 00 : 0.00 0.00 !38418 OK Does not overtop ,_ _ - -t-._ �r_ , +___ _• __� __.--- ___- _- _--• _ _- -Y---+---t----�---{- -�-- �_ . -+---° -+.. 100 CB it7076 CB it7059 383.27 i 381 71; 12 379.62 377 66 0 0.012 221.93; 0.86% 0 00 , 4 62 ' 0 213 0.069 0.282 S.DO 1.55 3.63 OK ; 1.97 ' 0.06 � 0.53 0.74 378.96' 0.36 i 0.03 0.06 �360J1':380.39 0 01 : 0.00 0.00 i 380J0 OK Does not overtop _,--- --_ _ _._�_ . --rt---- - -- ------ _�__--- ____ _-- - - -----�.�_ -- --� - - --- - _ _ _.. ___. _ . . .. --��---t� _-... � -.-r 100 CB#7059 CB#7575 !381 71;38036� 12 377 61 376 2 0 , 0.012 � 173 ' 0.82% 0 00� 4.44 4 0.244 ; 0.052 ; 0_296, S.DO 2.45 � 3.48 ''�. OK ; 3.12 i 0.15 ; 0.67 � 0.97 ,378.09'� OJO � 0.08 0.15 ,379.01-.378.67'�.�0.06 �0.00 : 0.00 +378.96 OK Does not overtop .._ �_.._. __._ a._ .._ .r_ __. ..�, _. ...__ ___._ '---�- .._. ��- ._ . .._.. - � � . � _.. � 100 CB#7575 CB tt8057 '380 36;378.89 12 376.16��.374 66 . 0�O.D12 -:19936 OJS% 0.00 . 4.26 �< 0.278��T0.043 0321 5.00 3.46 i 335 ��T4.41 j 030 , 0.80 1.21 '��376.18 1.60 � 015 0.30 3 44,377.60: 0.15 0.00 0.00 �378.09 OK Does nat overtop _.. _.__.. ._. ,.- - --- -�._._. _.. � ---- _ . .. 100 .CB#8057 CB 38 '�378 89 378488�_32_ 374.66�372 38 D ! O.D12� 19 12_00% 0.00 17 02 ; 0.234 : 0.053 0.287 ��, �5.00 433 ' 13.37 OK ! 5.51 ! 0.47 ; 0.87 1.42 '��373.91 OZ4 0.24 0.47 �37637��:376.48 0.30 0.01 , 0.00 ��376.18 OK Does nat overtop _ 100 CB 38 �CB 40 �,378 88';377.85 I 12 372 38.372 Ol^�� 0't D.012 ': 48.92 0.76:G 0.13� 4.27 : 0.000 � 0.000 0.000 5.00 4.46 3.36�_5.68 : 0.50 j 0.88 1.46 i 372.95 E 0.65 OZS 0.50 3�7436 f 37433 0.47 ! 0.01 ; 0.01 !373.91 OK Does not overtop � _. _. _ . . . .. __ Y.�.__�� . _` _ _.__ � ____.� _.. ,, ::�--.-_ _ . . . : ��- : , . �- . k � � . , . . . : � : . ' . . ;� _._ . . . .- 1_._'-,�}__-� -'_ ___._ { .___-__.._.. t--- : � : . --r---:._..__ �__ i � i . _-----i--.� ' i � € � -i i ,' � - � � ( - � ' � - ' - -_ -:-- .�.- - - - --- ---- -- ; � - - --. _. 1_____'_._ �_ _.-�- ___ _-- '--__ -__ ___ .�_ --.� ___ _ '_---�---- . __'. _ _ �___ .__ _._-__ �_ .__ 1____'--- � _._._-_..---- -�---• - ----i. __ ___ i I 115EA13lcivil',1 1 3001-1 1 325011 1 31 5 8(Vantage GlenjIPROJECT DOCUMENTS`,Storm DrainageiOetConv Calcs�CONV(ASBUILT)\Backwater ROW_ASBUILT.xlsm k ff Appendix C Special Reports and Studies Vantage Point Apartments Technical Information Report Appendix C COKPORATED AREAS 530071 5'5 APPROXIMATE SCAi E IN FEET 500 0 500 sourf;Fasr , II,�I NATIONAL FLOOD INSURANCE PR06RAM ,�sr� srRFFr lu�,l �,I�lllil'�II __— ---- -- - ;, �I i,� � _ _ _ _--- -- ------- --____ - - w -- I�� I�! FIRM � _ �I � FLOOD INSURANCE RATE MAP � i�� / � �� '�''� KING COUNTY, w i � I WASHINGTON ANll > I INCORPORATED AREAS a , � � �, I � T � j! 'll li I' PANEL 919 OF 1725 , � .�� ;�� ,�.: ��,� �o�;�� ; �� ,�.,-E�,� ET � J I il il j � I a W �� I�I��I'i � W _ � ~ Z �I, �I I rr y; � Q �I,I��I� � ��'�U`l1=Y NUMBCR VANE� SU�F'X I II I� 'I I��!. V Z 1� I I "rnr c:r o� swww w:v v F— � i � �,eoor+rv � a° �� ' n��icoNror+aieo an.as s�o�n x�e � �i!�i �,i.�� i� r ,� avn oa�: � i 2 � 0 32 �� I 'I �I'I ' i I I ZONE X � i ' j�� , ��I � I � '��i!I�� MAP NUMBER �� i�'��'��'i 53033C0919 F .�\ I II I;I;�I � � L : --_-�� MAP REVISED: �� `'-'�'� MAY 16,1995 SITE '�;m��6��'f� ,8 �- \ . `�� ,,�� ,, ,�".% i � I I III Ii�l�; Federal Emergency Managemen[Agrncy � I \ I '__ \ Thie is an official copy of a poRion of the above referenced flood map. It was extracted uaing F-MIT On-Line. This map does notrellect chanqes or amendments which may have been made subsequent to the date on the � tltle block. For the latest product information about National Flood Insurance Proflrem 11ood maps check the FEMA Flood Map Store at www mac.fema.gov / , / / �DESIGN� � , � �� \ \ \ � 1 % I � REPORT OF GEOTECHNICAL ENGINEERING SERVICES Vantage Point- Multi-Family Rental Project Vantage Glen Community 17901 105"' Place SE ' Renton, Washington , For Vantage Point Apartments LLC c/o King County Housing Authority February 24, 2014 GeoDesign Project: KCHA-29-03 i C�DESIGI�C �` '�� February 24, 2014 `` Vantage Point Apartments LLC I c/o King County Housing Authority Capital Construction Department 625 Andover Park West, Suite 107 Seattle,WA 98188 Attention: Mr. Tim Locke Report of Geotechnical Engineering Services Vantage Point - Multi-Family Rental Project Vantage Glen Community 17901 105"' Place SE Renton, Washington GeoDesign Project: KCHA-29-03 GeoDesign, Inc. is pleased to submit this report that summarizes our geotechnical engineering services to support the development of multi-family housing at the Vantage Glen Community in Renton,Washington. This report has been prepared in accordance with discussions, our proposal dated November 15, 2013, and includes information from our prior report entitled Report of Geotechnical Engineering Services; Vantage Glen -Multi-Family Rental Projed; Vantage Glen; 1790T )OS"' Place SE;Renton, Washington, dated March 21 , 2013. This report updates and supersedes the prior report. ♦ ♦ ♦ 10700 Meridian Avenue North,Suite 210 I Seattle,WA 98133 I 206.838.9900 www.geodesigninc.com We appreciate the opportunity to be of service to you. Please contact us if you have questions regarding this report. Sincerely, GeoDesign, Inc. � C�' ��`'� /—I '� �'t Thomas A.Tobin, P.E. Principal Engineer cc: Ms. Pam Derry,Tonkin/Hoyne Architecture & Urban Design (via email only) Mr. Alberto Cisneros, KPFF Consulting Engineers (via email only) Ms.Anna Nelson,Van Ness Feldman LLP(via email only) TAP:TAT:kt ' Attachments One copy submitted(via email only) Document ID: KCHA-29-03-022414-geor.docx O 2014 GeoDesign,Inc. All rights reserved. `�•,��I�N: 2 KCHA-29-03:021814 TABLE OF CONTENTS PAGE NO. 1.0 INTRODUCTION 1 2.0 PURPOSE AND SCOPE OF WORK 1 3.0 SITE CONDITIONS 2 3.1 General 2 3.2 SurFace Conditions 2 3.3 Subsurface Conditions 3 3.4 Groundwater 4 4.0 INFILTRATION TESTING 4 5.0 LABORATORY TESTING 4 6.0 DESIGN RECOMMENDATIONS 5 6.1 General 5 6.2 Seismic Design Criteria 6 6.3 Foundation Support- Shallow Spread Footings 7 6.4 Concrete Slab on Grade 9 6.5 Below-Grade Walls and Retaining Walls 10 6.6 Stormwater Infiltration Evaluation 12 6.7 Pavement Design 13 6.8 Stormwater Pond Mounding Analysis 19 7.0 SEWER IN STEEP SLOPE AREA 20 7.1 Slope Topography 20 7.2 Subsurface Soils 21 7.3 Sewer Pipeline Recommendations 21 7.4 Erosion Protection 23 8.0 SITE DEVELOPMENT 24 8.1 Site Preparation 24 8.2 Excavation 26 8.3 Fill Materials 26 8.4 Geosynthetics 28 8.5 Construction Stormwater Considerations 29 8.6 Wet Weather Considerations 29 9.0 OBSERVATION OF CONSTRUCTION 30 10.0 LIMITATIONS 31 REFERENCES 32 FIGURES Vicinity Map Figure 1 Site Plan Figure 2 1985 Aerial Photograph of Vantage Glen Site Figure 3 Site Area Modified by Previous Legal Grading Figure 4 Existing Steep Slope and Erosion Hazard Areas Figure 5 New Steep Slope and Erosion Hazard Areas Figure 6 ��13■J�ES I L N KCHA-Z9-03:022414 TABLE OF CONTENTS PAGE NO. APPENDICES Appendix A Field Explorations A-1 Laboratory Testing A-1 Exploration Key Table A-1 Soil Classification System Table A-2 Boring Logs Figures A-1 -A-5 Grain-Size Test Results Figure A-6 Summary of Laboratory Data Figure A-7 Appendix B Prior Exploration Logs Appendix C Analytical Resources, Inc. Laboratory Report Appendix D Richard Martin Groundwater, LLC, Stormwater Infiltration and Mounding Analysis Report ACRONYMS ��13•�ESIL�1 KCHA-29-03:02241 4 1.0 INTRODUCTION � This report presents the results of GeoDesign's geotechnical engineering services for the development of multi-family housing at the Vantage Glen Community in Renton,Washington. The Vantage Glen Community is located south and west of the intersection of SE 180"'Street and 105"' Place SE. The existing Vantage Glen Community consists of single-family manufactured homes and a community center. We understand the proposed development will be multi-family housing. As currently planned, the housing will include the construction of multi-story apartments and associated infrastructure (parking and utilities). We understand that significant site grading is anticipated to include excavations for below-grade parking under the buildings and construction of a stormwater management pond. Our proposal was submitted to KCHA on November 15, 2013 and subsequently approved by contract number CD1100165,Task Order Number 18, dated November 25, 2013. Our initial geotechnical report was submitted to KCHA on March 21, �013. This updated report is issued to provide additional recommendations for new and/or revised project considerations that have arisen as the project design evolved. This report includes all of the prior report information and supersedes the prior report. We also updated the Geologic Hazards Report for the project. The original report was issued on February 27, 2013; the updated report was issued on�anuary 16, 2014. For your reference, definitions of all acronyms used herein are defined at the end of this document. 2.0 PURPOSE AND SCOPE OF WORK The purpose of this study was to complete additional subsurface explorations and provide additional geotechnical recommendations for the final design phase. Our scope of work included conducting a site reconnaissance, drilling and sampling five exploratory borings, performing laboratory testing,and completing engineering analyses to develop the geotechnical conclusions and recommendations presented in this report. Specifically, we performed the following: • Collected and reviewed readily available geotechnical and geological data for the project area. • Reviewed our existing report, including historical aerial photographs of the site, to identify areas where historical grading or mining has taken place and to identify slopes created by those activities. • Coordinated and managed the field investigation, including public utility locates and scheduling of contractors and GeoDesign staff. ��li�.U�IG N- 1 KCHA-29-03:022414 • Completed the following explorations to evaluate the subsurface conditions at the site: ■ Five additional borings to depths of up to 61.5 feet BGS o Performed infiltration tests in the augers at the approximate elevation of the ba5e of the pond o Installed a well to a depth of 60 feet BGS to monitor high groundwater levels during the wet season • Completed laboratory analyses on selected disturbed soil samples obtained from the explorations to determine certain index properties of the on-site soil. • Performed engineering analyses and evaluated data derived from the subsurface investigation and laboratory testing program. • Prepared this report summarizing our findings, conclusions, and recommendations related to the following: ■ Subsurface soil and groundwater conditions and results of laboratory testing ■ Estimate of preliminary infiltration rates for design of the stormwater pond, including laboratory testing to evaluate water quality treatment capacity of native soils based on CEC and organic matter content testing ■ Groundwater mounding analysis to determine the effect of the infiltration at the stormwater pond on the surrounding properties ■ Slope analysis with post-pond groundwater levels ■ Waterproofing recommendation for the below-grade parking basement walls ■ Hillside pipeline recommendations ■ Underslab drainage recommendations ■ Grasscrete pavement evaluation GeoDesign's scope of work did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or groundwater at this site. 3.0 SITE CONDITIONS 3.1 GENERAL The Vantage Glen Community is located south and west of the intersection of SE 180'h Street and 105"' Place SE. The proposed multi-family housing project site includes the two adjoining undeveloped parcels to the north and the east of the existing communities (parcel numbers 3223059363 and 3223059362). The two parcels form an "L" shape (approximately 5 acres in size), a portion of which is bordered by 180`h Avenue SE to the north and 105"' Place SE to the east, an apartment complex on the north, and by the KCHA Vantage Glen residential community on the west and south. Surficial conditions were determined from observations during several visits to the site. Subsurface conditions throughout the site were evaluated by completing our explorations. 3.2 SURFACE CONDJTIONS The site is located on a slope that ascends gradually upwards from SE 180th Street and 105"' Place SE to a ridge that generally defines the western and southern boundary between the two undeveloped parcels. West and south of the ridge, the ground descends steeply down to the ��•Jv��GN= 2 KCHA-29-03:022414 backyards of the Vantage Glen Community homes on 104`h Avenue SE and SE 181't Street. The slope gradients in this area vary from 40 percent to approximately 60 percent,with a change in elevation varying from 30 to 45 feet, and the slope meets the definition for steep slope geologic hazard areas as defined by the King County land use codes. We concluded that the Vantage Glen property and surrounding undeveloped parcels owned by KCHA have been extensively graded during past aggregate mining activities on the property and that the slopes were created as a result of mining activity. 3.3 SUBSURFACE CONDITIONS Subsurface conditions were explored within the proposed development area by drilling four borings during the initial phase of work at the site conducted during February 2013. We also completed 1 1 test pits during the initia) phase. Those borings and test pits were documented in our March 21 , 2013 report and are included herein for completeness. The recent explorations included drilling five additional borings (B-5 through B-9) to depths ranging between 16.5 and 61.5 feet BGS in December 2013. Borings B-5 through B-7 were completed in the area of the proposed stormwater pond. Initially, the borings were drilled to a depth of 12.0 feet BGS where infiltration tests were performed. The borings continued to a depth of 31.5 feet BGS in B-5 and B-7 and to 61.5 feet BGS in boring B-6. Borings B-8 and B-9 were completed along the slope on the western portion of the site. The exploration locations are shown on Figure 2. Descriptions of the field explorations, exploration logs, and laboratory procedures for the additional explorations are included in Appendix A of this report. Exploration logs for the initial phase of work are presented in Appendix B. Subsurface conditions encountered at the boring locations are generally consistent with the subsurFace conditions described in our report dated March 21, 2013. The soils encountered in the bottom of the pond and along the western slope are described below. 3.3.1 Stormwater pond Unengineered fill was encountered in the borings located in the pond area to a depth of approximately 1 foot BGS. The fill generally consist of silt with varying amounts of sand, gravel, and construction debris and silty sand with minor gravel. Beneath the fill, native soil was encountered. The native soil consists of intermixed sand, silt, and small amounts of gravel that were deposited by glaciers. The sand is medium dense to very dense and the silt is stiff to very stiff or hard. 3.3.2 Western Slope The soil along the slope on the western side of the site consists of sand with varying amounts of silt and sandy silt with varying amounts of gravel. The sand is dense to very dense and the sandy silt encountered in the upper 8 feet of B-8 is stiff. �DE51GN 3 KCHA-29-03:022414 3.4 GROUNDWATER Groundwater was encountered in boring B-6 at approximately 45 feet BGS during drilling. A well was installed to a depth of 60.0 feet BGS. The groundwater level datalogger was installed in the well so that water levels can be obtained throughout the wet season to determine the seasonal high groundwater level. 4.0 INFILTRATION TESIING Infiltration testing was performed at the three borings in the pond area. The testing was completed in general accordance with the EPA falling head percolation test procedure provided in the King County 2009 SWDM (King Counry, 2009). The tests were performed at a depth of approximately 12 feet BGS or the approximate depth of the infiltration facility. Several tests were completed at each location after the saturation period. The test results are presented in Appendix C. 5.0 LABORATORY TESTING Laboratory tests were conducted on specific soil samples selected from the exploration5 to assist in characterizing certain physical parameters of the soil. Index tests that were performed included the determination of natural water content and grain-size distribution determinations. These tests were performed in GeoDesign's accredited soils laboratory. All tests were conducted in general accordance with appropriate ASTM standards (ASTM, 201 1). A discussion of laboratory test methodology and test results are presented in Appendix A. Test results are also displayed where appropriate on the exploration logs in Appendix A. CEC and organic matter tests were completed on samples located at or near the anticipated base of the infiltration facility to evaluate soil capacity for water qualiry treatment. The CEC tests and , organic matter tests were performed by Analytical Resources, Inc. A summary of test results is ' provided in Table 1. The test results are presented in Appendix B. Table 1. Soil Analytical Results Summary ' Boring Sample Depth CEC' Organic Content !I (feet BGS) (meq per 100 grams) (percent) II B-5 15.0 8.6 OJ B-6 15.0 7.4 0.6 I B-7 15.0 7J 0.9 � 1. Suitability for Water Quality Treatment: CEC greater than 5 meq per 10�grams and organic matter content a minimum of Q.5 percent(King County,2009) �i � ��IGN` 4 KCHA-29-03:022414 6.0 DESIGN RECOMMENDATIONS 6.1 GENERAL Based on our review of available information; the development history of the site; and the results of our explorations, laboratory testing, and analyses, it is our opinion that the site is suitable for construction of the proposed multi-family housing project and associated improvements. The following are key considerations for this development: • The Puget Sound area is a seismically active region. The dense, glacially consolidated material underlying the site at depths below 10.0 to 15.0 feet BGS is not conducive to amplifying earthquake ground motions and is not susceptible to liquefaction or lateral spreading. We did not observe evidence of faults on the site in the explorations or on geologic maps of the area and have concluded that the probability of surface rupture is low. We have provided appropriate seismic design recommendations based on the 2012 IBC criteria. • Fill that is unengineered was encountered over much of the site. The fill is less than 5 feet thick over much of the site; however, it ranges to as much as 13 feet thick in the area west of the intersection of SE 180"'Street and 105"' Place SE. The fill frequently contains some localized demolition rubble and debris. This fill is not suitable for direct support of the structures and must be removed and replaced with compacted structural fill for adequate building support. Alternatively,the fill could be penetrated with an intermediate subsurface ground improvement system (such as rammed aggregate piers or stone columns)to provide adequate support for the building foundations and slabs-on-grade. The fill can remain in place outside of the building areas. • Where deeper fill is not present, shallow spread footing foundations bearing on an improved subgrade, prepared as recommended in the "Foundation Support - Shallow Spread Footings" section of this report,will provide adequate support for the proposed buildings. • The building floor slab can be supported on grade, provided the subgrade is prepared as recommended in the "Concrete Slab on Grade" section of this report. • We recommend installing an underslab drainage collection and discharge system below the slabs. The underslab drainage system should consist of at least 12 inches of 1.5-inch-minus clean crushed gravel with negligible sand or silt NNSS 9-03.1(4)C, Grading, No. 57). The gravel layer should be placed between deepened foundation elements or below the slab/mat foundations, but should not be placed below the deepened foundation elements. • Retaining walls will be required to support the west margin of the Grasscrete access road ' around the west side of the building and at other locations where grade transitions cannot be '� sloped. Recommendations are presented for MSE walls and concrete cantilever retaining I i walls. � `�•J��G N" 5 KCHA-29-03:022414 - • Sufficient separation of more than 5 feet exists between the anticipated bottom of the stormwater pond and the groundwater table and confining layers. The separation is necessary to support infiltration and avoid groundwater mounding. • Soil exposed at the anticipated base of the stormwater pond will consist of sandy silt interbedded with silty sand. We recommend a design long-term infiltration rate of 0.4 inch per hour for design of the stormwater pond. • The soil below the base of the stormwater pond meets the soil suitability criteria for stormwater treatment. The King County 2009 SWDM soil suitabiliry criteria requires a CEC of at least 5 meq per 100 grams and an organic content of at least 0.5 percent. • Both traditional HMA and pervious HMA pavements are planned for this project. Recommendations are presented for the following pavement sections. ■ Traditional HMA pavement will be used to construct the access driveways and the drive aisles in the parking areas. ■ Pervious HMA will be used in the parking stall areas. ■ A perimeter emergency access road around the west and south sides of the main building will be surFaced with Grasscrete. • A perimeter emergency access road around the west and south sides of the main building will be surfaced with Grasscrete. A summary of our evaluation of the Grasscrete pavement is included in this report. • Recommendations for the construction of the sewer in the steep slope are presented. Recommendations include site preparation, pipe construction, erosion control, and securing and bedding recommendations. Our specific recommendations for design and guidelines for development of the site are presented in the following sections of this report. These should be incorporated into design and implemented during construction of the proposed development. 6.2 SEISMIC DESIGN CRITERIA Moderate to high levels of earthquake shaking should be anticipated during the design life of the building, and it should be designed to resist earthquake loading in accordance with the methodology described in the 2012 IBC. The recommended seismic design parameters for the proposed residential buildings, based on the 2012 IBC, are presented in Table 2. ��1-�1�.��G N' 6 KCHA-29-03:022414 Table 2. IBC Seismic Design Parameters Seismic Design Parameter Short Period 1-Secand Period MCE Spectral Acceleration SS= 1.393 g S� = 0.519 g Site Class C Site CoefFicient F = 1 F = 1.364 a v Adjusted Spectral Acceleration S�= 1.393 g SM� = 0.675 g Design Spectral Response Acceleration Parameters S�= 0.929 Sp� = 0.450 g 6.3 FOUNDATION SUPPORT-SHALLOW SPREAD FODTINGS 6.3.1 General Conventional shallow spread footings will provide adequate support for the anticipated building loads. Loose to medium dense and/or soft to very stiff fill was rypically encountered to depths ranging between 1.0 and 13.0 feet BGS. Laboratory tests indicate that the moisture content of the fill is significantly above the optimum moisture content. Subgrade improvement measures that consist of over-excavation and replacement of a portion of the unengineered fill below foundation elements will be necessary to provide adequate foundation support. We recommend fully over-excavating the existing fill and re-compacting the material as structural fill. Any rubble or debris should be removed from the fill material prior to replacing it as structural fill. The structural fill should be placed in lifts with a maximum uncompacted thickness of 12 inches and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557. 6.3.2 Dimensions and Capacities Continuous and isolated spread footings should be at least 18 and 24 inches wide, respectively. The bottom of exterior footings should be at least 18 inches below the adjacent exterior grade for frost heave protection. Interior footings should be founded a minimum of 12 inches below the lowest adjacent soil grade. Foundations supported on the properly prepared subgrade may be designed for an allowable bearing pressure of 3,500 psf. This is a net bearing pressure; the weight of the footing and overlying backfill can be ignored in calculating footing sizes. The recommended allowable bearing pressure applies to the total of dead plus long-term live loads and may be increased by one-third to account for short-term live loads such as induced by wind or seismic forces. 6.3.3 Resistance to Sliding Wind, earthquakes, and unbalanced earth loads will subject the proposed buildings to lateral forces. Lateral loads on footings can be resisted by passive earth pressure on the sides of the buried portions of the foundations and by friction on the base of the footings. An allowable passive resistance may be calculated as a triangular equivalent fluid pressure distribution using ��13�.��IGN:� 7 KCHA-29-03:022414 an equivalent fluid density of 350 pcf, provided the footings are surrounded with properly placed and compacted structural fill and the footing is above the groundwater table. Adjacent floor slabs, pavements, or the upper 12-inch depth of adjacent unpaved areas 5hould not be considered when calculating passive resistance. For footings in contact with structural , backfill, a coefficient of friction equal to 0.40 may be used. A safety factor of 1.5 has been applied to the recommended sliding friction and passive pressure. 6.3.4 Settlement We estimate that total post-construction static (consolidation-induced) settlement for conventional and semi-rigid foundation systems should be less than 1 inch, with differential settlement of up to%z inch measured along 25 feet of continuous wall footings or between similarly loaded adjacent footings. We expect that settlement for these conditions will tend to occur rapidly after the loads are applied. Immediately prior to placing concrete, all debris and soil slough that accumulated in the footings during forming and steel placement must be removed. Debris or loose soil not removed from the footing excavations will result in increased settlement. , 6.3.5 Footing Drains We recommend that footings and basement walls around the buildings be provided with drainage to help manage potential perched groundwater in the upper fill and native soil. Footing drains can consist of free-draining material or prefabricated drainage panel products, with perforated pipes to discharge the collected water. Drainage behind basement walls is described in the "Below-Grade Walls and Retaining Walls" section of this report. The free-draining material should consist of drain rock as specified in the "Fill Materials" section of this report. Alternatively,the free-draining material can consist of clean gravel; however, the gravel should be fully encapsulated within a suitable geotextile filter fabric, such as Mirafi 140N (or similar material). The drainage material should be at least 1 foot wide and extend from the base level of the footing to within 1 foot of the ground surface. The free-draining material should be capped with less permeable material, such as the on-site soil. Prefabricated drainage panel products, such as Mirafi Miradrain 6000 (or similar material), consist of a geotextile filter fabric bonded to a molded plastic drainage element. The drainage panel is placed directly against the footing and stem wall and should extend from the base level of the footing to approximately 1 foot from finished grade. The oanel should also be mvPrPd with 1 foot of less permeable material, such as the on-site so '. Footing drains should include a 4-inch-diameter, perforated solid pipe or rigid corrugat� polyethylene pipe (ADS N-12 or equal) near the base level of the footing. Where free-dra�n�ng material is used,the pipe should be installed with approximately 3 inches of drainage material below the pipe. With drainage panels, the geotextile filter fabric should extend from the panel to wrap around the pipe. The pipes should be laid with minimum slopes of% percent and discharge into a sump or a water collection system to convey the water away from the building. _� L�•Jv��GN�' 8 KCHA-29-03:022414 The pipe installations should include cleanout risers located at the upper end of each pipe run. We recommend that the cleanouts be covered and placed in flush-mounted utility boxes. We recommend that roof downspouts not discharge into the footing drain perforated pipes. 6.4 CONCRETE SLAB ON GRADE 6.4.1 General Conventional slabs may be supported on grade, provided the subgrade soil is prepared as recommended in "Fill Materials" section of this report. We recommend that the slab be founded on struRural fill. For slabs designed as a beam on an elastic foundation, a modulus of subgrade reaction of 1 50 pci may be used for subgrade soil prepared as recommended. We recommend that exterior slabs, such as those for walkways, be structurally independent from the structure foundations. This will allow minor movement of the slabs to occur as a result of vehicular loading, tree root growth, seasonal soil shifting, and other factors, while reducing the potential for slab cracking around the perimeter. Interior slabs may be tied to the strudure's foundation system. 6.4.2 Underslab Drainage Water seepage and accumulation beneath the basement floor slabs could result in a wet floor condition and/or uplift pressures on the floor slabs. To help prevent this, we recommend installing an underslab drainage collection and discharge system below the slabs. The underslab drainage system should consist of at least 12 inches of 1 .5-inch-minus clean crushed gravel with negligible sand or silt (WSS 9-03.1(4)C, Grading, No. 57�. The gravel layer should be placed between deepened foundation elements or below the slab/mat foundations, but should not be placed below the deepened foundation elements. A network of minimum 4-inch-diameter perforated collector pipes should be placed at the base of the gravel and should be spaced 20 feet on center. The drainage collector pipe should be either machine slotted or perforated. The underslab drainage system pipes should be routed to discharge into a sump to pump the collected water to the site drainage facilities. We recommend using either heavy-wall solid pipe (SDR-35 PVC) or rigid corrugated polyethylene pipe (ADS N-12, or equal) for the collector pipes. We recommend against using flexible tubing for collector pipes. A geotextile filter fabric should be placed between the 12-inch-thick gravel layer and the native soil subgrade to maintain separation and reduce piping of the fine-grained soil up into the gravel. The geotextile should be non-woven and conform to the specifications for Class A, underground drainage material provided in WSS 9-33.2(1) -Geotextile Properties, Table 2 Geotextile for Underground Drainage. The geotextile should be installed in conformance with the specifications provided in WSS 2-12 -Construction Geosynthetic. The amount of groundwater flow entering the underslab drainage system in each basement area is not expected to be significant. We estimate that the flow from a passive drainage system under each basement slab area will typically be in the range of 1 to 2 gpm, depending on the depth of the f nal structure configuration. If the basement wall backdralns are routed to the .��UU l.'�� 9 KCHA-Z9 03.02241-: same sumps,the flow combined amounts should be increased to approximately 2 to 4 gpm. However,we recommend that the sumps be sized to accommodate larger pumps if larger flows are experienced. To help prevent basement slab and wall wetness,we recommend that the slabs and walls be waterproofed. The waterproofing sh�uld be designed by a waterproofing expert. 6.5 BELOW-GRADE WALLS AND RETAINING WALLS 6.5.1 General The following recommendations should be used for the design of below-grade walls that are , intended to act as retaining walls and for other retaining structures that are used to achieve grade changes. 6.5.2 Design Parameters Lateral earth pressures for design of below-grade walls and retaining structures should be evaluated using an equivalent fluid density of 35 pcf, provided that the walls will not be restrained against rotation when backfill is placed. If the walls will be restrained from rotation (i.e., basement walls internally braced by the floor slabs), we recommend using an equivalent fluid density of 55 pcf. Walls are assumed to be restrained if top movement during backfilling is less than H/1 ,000, where H is the wall height. These lateral soil pressures assume that the ground surface behind the wall is horizontal. For unrestrained walls with backfill sloping up at 2H:1 V,the design lateral earth pressure should be increased to 55 pcf, while restrained walls with a 2H:1 V sloping backfill should be designed using an equivalent fluid density of 75 pcf. These lateral soil pressures do not include the effects of surcharges such as floor loads, traffic loads, or other surface loading. Below-grade walls for the buildings should also include seismic earth pressures. Seismic earth pressures should be determined using a rectangular distribution of 7H psf, where H is the wall height. If vehicles can approach the tops of exterior walls to within one-half the height of the wall, a itraffic surcharge should be added to the wall pressure. For car parking areas, the traffic surcharge can be approximated by the equivalent weight of an additional 1 foot of soil backfill (125 psfl behind the wall. For truck parking areas and access driveway areas, the traffic surcharge can be approximated by the equivalent weight of an additional 2 feet (250 psfl of soil backfill behind the wall. The fire-fighting apparatus may impose higher surcharge loads than conventional trucks. We should review these loads to evaluate the wall surcharges during final design of the walls. Other surcharge loads, such as from foundations, construction equipment, or construction staging areas, should be considered on a case-by-case basis. These recommendations are based on the assumption that adequate backdrainage will be provided behind below-grade walls and retaining structures as discussed below. The values for soil bearing, frictional resistance, and passive resistance presented above for foundation design are applicable to retaining wall design. Walls located in level ground areas should be founded at a depth of 18 inches below the adjacent grade. An exception to this is for walls sited in dose proximity to descending ground. If the ground descends at a slope of 2H:1 V below a wall, a ', ►�1.3��1: 1 p KCHA-29-03:022414 minimum embedment depth of 4 feet will be required. The allowable passive resistance of the soil on the toes of these walls is also reduced for conditions where the ground descends below the wall. For a 2H:1 V descending slope, no passive resistance can be allowed for the upper-most 2 feet of embedment and a reduced allowable passive resistance of 150 psf can be used on the lower 2 feet of embedment. 6.5.3 Backdrainage To reduce the potential for hydrostatic water pressure buildup behind the retaining walls, we recommend that the walls be provided with backdrainage. Backdrainage can be achieved by using free-draining material with perforated pipes to discharge the collected water. Positive drainage should be provided behind below-grade walls and retaining walls by placing a minimum 2-foot-wide zone of free-draining backfill directly behind the wall. The free-draining backfill should meet the criteria for WSS 9-03.12(2)- Gravel Backfill for Walls. The free-draining backfill zone should extend from the base of the wall to within 2 feet of the finished ground surface. The top 2 feet of fill should consist of relatively impermeable soil to prevent infiltration of surface water into the wall drainage zone. A 4-inch-diameter perforated drainpipe should be installed within the free-draining material at the base of each wall. We recommend against using flexible tubing for the wall drainpipe. The footing drain recommended above can be incorporated into the bottom of the drainage zone and be used for this purpose. The pipes should be laid with minimum slopes of 0.5 percent and discharge into a sump or the stormwater collection system to convey the water off site. The pipe installations should include a cleanout riser with cover located at the upper end of each pipe run. The cleanouts could be placed in flush-mounted access boxes. We recommend against discharging roof downspouts into the perforated pipe providing wall backdrainage. Collected downspout water should be routed to appropriate discharge points in separate pipe systems. For exterior walls where seepage at the face of a wall is not objectionable, the walls can be provided with weep holes to discharge water from the free-draining wall backfill material. The weep holes should be 3 inches in diameter and spaced approximately every 8 feet center-to- center along the base of the walls. The weep holes should be backed with galvanized heavy wire mesh to help prevent loss of the backfill material. 6.5.4 Construction Considerations Exterior retaining walls used to achieve grade transitions or for landscaping can be constructed using traditional structural systems such as reinforced concrete, concrete masonry unit blocks, or rockeries. Alternatively,these walls can consist of reinforced soil and block-facing structures typically referred to as MSE walls. In recent years, the latter structural system has proven to be an economically reasonable aliernative to more traditional retaining wall systems. Because there are many proprietary MSE structure types available, it is typical for the wall provider to complete the design analysis for the wall that will be installed. The parameters given above for earth pressures and sliding resistance can also be used for design of MSE walls. These � ��G�1= 11 KCHA-29-03:022414 walls typically have reinforcement embedment lengths of approximately 80 percent of the height _ of the wall. Minimum embedment depth for MSE walls is 2 feet. We can provide additional design consideration5 for rockeries, if requested. li Care should be taken by the contractor during backfilling of retaining walls to avoid ' overstressing the walls. Backfill placed within approximately 5 feet of the walls should be compacted with hand-operated or small self-propelled equipment. Heavy compactors or other heavy construction equipment should not be used within approximately 5 feet of the walls. 6.6 STORMWATER INFILTRATION EVALUATION We anticipate that the bottom of the stormwater pond will be approximately 12 feet BGS. Soil conditions at the base are expected to be sandy silt interbedded with silty sand. Infiltration characteristics of the soil within the project area were evaluated through grain-size distribution tests and in situ testing using the falling head test procedure. The locations of the infiltration tests were selected to correspond with the proposed location of the stormwater pond. All of the tests were conducted in general accordance with the EPA falling head percolation test procedure. The tests were conducted at a depth of approximately 12 feet BGS near the anticipated base of the pond. The infiltration rate determined using falling head test methodology is a short-term infiltration rate. A correction factor is necessary to account for the small scale of the test and other factors in order to estimate the long-term design infiltration rate from the test. Additional corrections to the measured infiltration rate are necessary to account for testing uncertainties, depth to the water table or nearest impervious layer, geometry of the infiltration receptor, and long-term reduction in permeability due to biological activity and accumulation of fines. The recommended correction factors to be applied to the "short-term" rate measured in the tests are summarized as follows: • Correction factor F��accounts for uncertainties in testing methods. A correction factor of 0.3 is required by the King County 2009 SWDM for the EPA falling head percolation test. • Correction factor F�,accounts for the influence of the facility geometry and depth to the water table or impervious strata on the actual infiltration rate. A shallow water table or impervious layer will reduce the infiltration rate and will not be reflected in a small-scale test like the EPA falling head test. The correction factor is determined by the width of the proposed infiltration faciliry and the depth from the bottom of the proposed facility to the highest water table level or the nearest impervious layer, whichever is less. We recommend a correction factor F of 0.55. � • Correction factor F��9 accounts for reduction in infiltration rates over the long term due to the plugging of soil. The correction factor varies between 0.7 for loams and sandy loams to 1 .0 for coarse sand or cobbles. The site is underlain by fine-grained material that would be classified as loams or sandy loams, and a correction factor of 0.7 is recommended. ��L�l��G�= 12 KCHA-29-03:02 2414 The "long-term design infiltration rate" is determined by multiplying the measured rate by the recommended correction factors,which are equivalent to a combined correction factor of 0.12. Table 3 summarizes the infiltration test results along with the correction factor. Table 3. Sail Infiltration Rate Analysis' Infiltration Measured Long-Term Design Point �nfiltration Rate Infiltration RateZ (inches per hour) (inches per hour) B-5 4.6 0.5 5 B-6 5.2 0.62 B-7 2.2 0.26 1. For selected soil samples and test locations 2. Based on the recommended combined corredion factor of 0.18 in accordance with King County 2009 SWDM Stormwater infiltration will vary across the site due to the variability of the fine-grained alluvium underlying the surficial fill material. We recommend an overall long-term design infiltration rate of 0.4 inch per hour for design of the stormwater pond. 6.6.1 Soil Suitability for Treatment The soil below the planned base of the stormwater pond meets the King County 2009 SWDM for water quality treatment outside of groundwater protection areas. Infiltration will be controlled by the fine-grained layers composed of sandy silt and silt. A CEC of at least 5 meq per 100 grams and a minimum organic content of 0.5 percent are required for water quality treatment(King County SWDM, 2009). Test results indicate that the CEC ranges between 7.4 and 8.6 meq per 100 grams for the samples collected within 2 or 3 feet of the base of the pond, approximately 15 feet BGS,which meets the minimum criteria for treatment. Organic matter content of the soil ranges between 0.6 and 0.9 percent in tested samples,which is greater than 0.5 percent minimum requirement per the design manual. 6.7 PAVEMENT DESIGN 6.7.1 General We understand that both traditional HMA and pervious HMA pavements are planned for this project. Traditional HMA pavement will be used to construct the access driveways and the drive aisles in the parking areas. Pervious HMA will be used in the parking stall areas. In addition, a perimeter emergency access road around the west and south sides of the main building will be surfaced with Grasscrete. Parking areas will be subject to light automobile traffic. Access driveways will be subject to moderate traffic loading from light delivery trucks and moderately heavy garbage trucks. The Grasscrete road will be subject to light loads from maintenance vehicles and moderately heavy fire-fighting apparatus if needed. We understand that the concrete sidewalk area adjacent to the Grasscrete road will also be designed for moderatelv heavy fire-fighting a�-: _ . %.. ��U�_�i�,i'v I 3 KCHA-29-03:02241 4 6J.2 Traditional HMA Pavement The traditional HMA should be HMA Class %Z-inch PG 64-22, with aggregate, gradation, and I asphalt requirements in accordance with WSS Section 9-03.8(6) - HMA Proportions of Materials. I This HMA should be compacted to 91 percent of the maximum specific gravity of the mix, as � determined by ASTM D 2�41. Minimum lift thickness for%z-inch HMA is 1 .5 inches. Asphalt binder should be performance graded and conform to PG 64-22. The aggregate base material should meet the specifications for aggregate base rock provided in the "Structural Fill" section of this report. The subgrade should be compacted to at least 95 percent of the maximum dry density, as determined by ASTM D 1557. 6.7.2.1 Access Roadway We recommend a pavement section consisting of 3 inches of HMA over 6 inches of 1'/.-inch- minus crushed rock in accordance with WSS 9-03.9(3) -Crushed Surfacing Base Course. Alternatively, an applicable pavement section using ATB would consist of 4 inches of ATB and 4 inches of base course. 6.7.2.2 Parking Area Drive Aisles For the drive aisles in areas limited to automobile traffic only,we recommend a pavement section consisting of 2.5 inches of HMA over 4 inches of 1%.-inch-minus crushed rock in accordance with WSS 9-03.9(3) - Crushed Surfacing Base Course. Alternatively, an applicable section using ATB would consist of 3 inches ofATB and 2.5 inches of base course. 6.7.3 Pervious HMA Pervious pavement is constructed of difFerent materials and layer thicknesses than traditional HMA pavement. To promote infiltration through the HMA layer, more open-graded aggregate is used in the HMA mix and a different binder grade may be used. To provide water storage the crushed base material below the HMA is thicker and also more open-graded than the base course recommended by WSS. To help reduce penetration of the HMA into the open-graded water storage material, a thin choker layer is placed between the water storage material and the HMA. Similarly, a geotextile fabric is placed on the native subgrade soil to help prevent penetration of the subgrade soil into the water storage layer. HMA used for pervious asphalt pavement should be designed as a%z-inch nominal, open-graded HMA. Selection of the preferred aggregate size should be based on the desired surface texture and the required layer thickness limitations. A recommended aggregate gradation for pervious asphalt is provided in Table 4. �DE51GN- i a KCHA-29-03:022414 ; j Table 4. Pervious HMA Gradation (% inch) Sie�e Size � �nch Percent Passing 1-inch 3/.-inch 99 - 100 1/2-inch 90 - 98 3/8-inch #4 18 - 32 #8 3 - 15 #200 0 - 3 Recommended Layer Thickness 3 (inches) Asphalt binders to construct pervious asphalt pavement include PG 64-22 and PG 70-22. The preferred and recommended asphalt binder is PG 70-22ER (polymer modified); however, its availability can be limited because some of the local asphalt suppliers limit their on-hand binder to PG 64-22. PG 70-22ER is available but is typically stocked by asphalt suppliers for a specific project,which requires pre-ordering it so that it is available when needed. Suppliers prefer a project size of approximately 600 tons of asphalt in order to utilize a complete tanker volume of the binder. The availability and use of PG 70-22ER is further restricted to the warm months of the year because of its stiffness, so it is not readily available between October and May. Projects specifying PG 70-22ER should be scheduled accordingly and specifications should address supplier availability. The binder should be between 5.5 and 6 percent of the pavement section by weight. Compaction of the pervious HMA should consist of approximately two to four complete passes by an 8-ton, dual, steel roller compactor working in static mode only. 6.7.3.1 Pervious Pavement Subgrade Preparation The subgrade for pervious pavements should be relatively flat (less than 3 percent slope)to prevent uneven ponding of water within the storage aggregate. The exposed subgrade should be proofrolled with a fully loaded dump truck or similar heavy, rubber-tire construction equipment to identify soft, loose, or unsuitable areas. If areas of excessive yielding are identified, the material should be excavated and replaced with water storage aggregate. The subgrade should be compacted to a maximum of 92 percent of the maximum dry density, ' as determined by ASTM D 1557. , �r13��IGN: 1 5 KCHA-29-03:022414 Exposed subgrades will be moisture sensitive and will deteriorate under construction traffic loading under wet conditions. If earthwork construction is expected to extend into the wet season,we recommend limiting the size of the work area and stabilizing the exposed surface by placing the water storage aggregate to protect the subgrade. Construction traffic should be kept off of the pervious pavement subgrade. 6.7.3.2 Subgrade Geotextile A layer of geotextile fabric should be placed as a barrier between the native soil subgrade and the water storage aggregate. The geotextile should be non-woven and conform to the specifications for Class A, underground drainage material provided in WSS 9-33.2(1) -Geotextile Properties,Table 2 Geotextile for Underground Drainage. The geotextile should be installed in conformance with the specifications provided in WSS 2-12 - Construction Geosynthetic. 6.7.3.3 Pervious PavemenC Water Storage Aggregate We recommend that the water storage aggregate layer be 12 inches thick. Imported granular material used as water storage aggregate beneath pervious pavements should be clean crushed rock or crushed gravel and sand that meets the criteria of WSS 9-03.9(2) - Permeable Ballast. Recommended gradations for acceptable storage aggregate are provided in Table 5. Table 5. Pervious Pavement Water Storage Aggregate WSS Sieve Size Permeable Ballast Percent Passing 2%Z inches 90 - 100 2 inches 65 - 100 1%z inches 1 inch 40 - 80 % inch %z inch No. 4 0 - 5 No. 100 0- 2 Percent Fracture 75 The storage aggregate should be placed in one lift and be compacted to a firm condition. Over compaction and construction traffic should be avoided. 6.7.3.4 Pervious Pavement Choker Aggregate Imported granular material used as choker aggregate beneath pervious pavements should be clean crushed rock that meets the criteria of WSS 9-03.9(3) - Crushed Surfacing Top Course. 6.7.3.5 Pervious Pavemenr Considerations We recommend the following considerations for installation of pervious pavement: ��L�-��G�= 16 KCHA-29-03:022414 • The long-term performance of pervious pavements is reliant upon proper design, installation, and long-term maintenance. Although design life of pervious asphalt pavement installations in parking areas is commonly indicated to be greater than 20 years,we recommend an assumed pavement design life of between 15 to 20 years. • Consideration should be given to limiting the use of pervious pavement to the parking strip and sidewalk areas,while still constructing a water storage aggregate layer beneath the entire roadway. Run-off from the entire roadway can be infiltrated through the parking strip area and into the storage aggregate while reducing construction and long-term maintenance costs. Contributory non-pervious areas to pervious areas should not be more than two times the size of the pervious area. • Consideration should also be given to limiting the thickness of single layer pervious asphalt pavement to a maximum thickness of 4 inches. Sections thicker than 4 inches should be constructed using a layer of asphalt-treated pervious base below the pervious asphalt. • Sediment, organic debris, and bio-mass growth will reduce the permeability of pervious pavement. Regular periodic maintenance is required to maintain the hydrologic performance of the pavement. Maintenance should consist of periodic cleaning by regentative air sweeping and/or vacuum sweeping and flushing with high volume water at low pressure. Based on available information,vacuum sweeping should be performed two to four times per year and flushing at least once per year. • Sanding for snow and ice removal should be avoided on pervious pavement. • Public awareness plans should be developed to educate resident5 on activities that should be avoided on or adjacent to pervious pavement. • During and after construction, stockpiles of landscaping materials (e.g.,topsoil, bark dust, etc.) and construction materials (e.g., sand, gravel, etc.) should not be placed on the pervious pavements. Extreme care should be taken to prevent trafficking of muddy construction equipment over pervious pavements. • Landscaping areas that are adjacent to pervious pavements should be sloped or bermed to prevent run-off from washing debris onto the pavement and designed such that leaf debris does not accumulate on the pavement. These recommendations are based on general assumptions regarding anticipated traffic and assume adequate subgrade and drainage conditions. Pavement materials and placement should conform to WSS. 6.7.4 Grasscrete Pavement Grasscrete pavement is proposed for use to surface an access roadway that will be located around the rear of the future multi-family building complex. The pavement will provide emergency access to the rear of the building complex as well as for building and site maintenance equipment. ��13��G�I= 1 7 KCHA-29-03:022414 �_ J Grasscrete consists of reinforced concrete that is cast within a plastic cellular"former." The formers are available in several configurations and thicknesses to accommodate different vehicle loads. The concrete is underlain by coarse, open-graded gravel for support and load distribution as in traditional pavement sections. Once the concrete is cured, the exposed former surface is melted away and the internal open spaces are filled with topsoil that is subsequently seeded. The Grasscrete pavement is to be designed to support fire-fighting apparatus. Information from the City of Renton Fire Department indicates that the design fire-fighting apparatus weighs 72 kips (20-kip front and 52-kip rear axles) and utilizes outriggers that impose loads of up to 50.7 kips on pads that measure 26 inches by 26 inches. Grasscrete is a proprietary product manufactured by Grass Concrete Limited of the United Kingdom. We were provided product information for Grasscrete that included an installation brochure titled "Grasscrete, Cast Insitu Paving System" as well as a link to a web site that contained design information for the Grasscrete product (http://www.grasscrete.com/pdfs/GrasscreteBrochure.pdfl. We also reviewed other design information linked to the product site at www.grasscrete.com. Based on our review of the available Grasscrete produce information, the Grasscrete pavement appears to be capable of supporting the design fire-fighting apparatus loads. The information is _ given in the metric 51 system. The equivalent fire apparatus weight is 33 tonnes (1 metric tonne equals 2,205 pounds). For this vehicle weight, the following Grasscrete pavement section is recommended: • CG2 or CG2sc formers measuring 150 millimeters thick (5.9 inches)should be used. The concrete reinforcement should consist of A393 welded-wire mesh. To promote infiltration through the Grasscrete surface, it is underlain by open-graded water storage aggregate that is covered by a thin choker layer and underlain by a geotextile fabric placed on the prepared native subgrade. We recommend that the aggregate layer be 12 inches thick and consist of clean crushed rock or crushed gravel and sand that meets the criteria of W55 9-03.9(2) - Permeable Ballast. The choker layer should be 1 inch thick and meet the criteria of WSS 9-03.9(3) - Crushed Surfacing Top Course. The subgrade geotextile should be non- woven and conform to the specifications for Class A, underground drainage material provided in WSS 9-33.2(1)-Geotextile Properties,Table 2 Geotextile for Underground Drainage. The aggregate layer should be placed in one lift and compacted to a firm condition. Over compaction and construction trafFic should be avoided. Expansion joints within the pavement surface, edging details, concrete placement protocol, and other installation products and details should be consistent with the recommendations of the Grasscrete product manufacturer. We recommend that the contractor who installs the Grasscrete pavement have experience with this product and installation protocol. We also recommend that the Grasscrete manufacturer's representative review and approve this application and the selected installation contractor. �'�1��UL��t+�v 1 b KCHA-29-03:022414 The Grasscrete product relies on a soil subgrade with a bearing capacity of 45 kN/m2(900 psfl. In our opinion, the subgrade bearing capacity will exceed this requirement provided that it is properly prepared. The subgrade should be relatively flat (less than 3 percent slope)to prevent uneven ponding of water within the storage aggregate. The exposed subgrade should be proofrolled with a fully loaded dump truck or similar heavy, rubber-tire construction equipment to identify soft, loose, or unsuitable areas. If areas of excessive yielding are identified, the material should be excavated and replaced with water storage aggregate. The subgrade should be compacted to a maximum of 92 percent of the maximum dry density, as determined by ASTM D 15 5 7. Exposed subgrades will be moisture sensitive and will deteriorate under construction traffic loading under wet conditions. If earthwork construction is expected to extend into the wet season,we recommend limiting the size of the work area and stabilizing the exposed surface by placing the water storage aggregate to protect the subgrade. Construction traffic should be kept off of the Grasscrete subgrade. We understand that the 5-foot-wide sidewalk that is immediately adjacent to the Grasscrete access road is also considered to be part of the fire access road and needs to support the loads of the fire equipment. To accomplish this,we recommend upgrading the sidewalk section thicknesses to be essentially equal to the Grasscrete section thicknesses. We recommend the sidewalk section consist of a 6-inch-thick concrete surface, over a 1-inch- thick choker layer of Crushed Surfacing Top Course [1NSS 9-03.9(3)], over a 12-inch-thick aggregate layer of Permeable Ballast [WSS 9-03.9(2)], with a geotextile between the ballast and the prepared subgrade. The geotextile should be Class A, underground drainage material provided in WSS 9-33.2(1) -Geotextile Properties,Table 2 Geotextile for Underground Drainage. The same subgrade and material placement recommendations that were presented above for the Grasscrete area should be used for the sidewalk area. Because the sidewalk is immediately adjacent to the Grasscrete, using the same material thicknesses will facilitate construction of both pavement areas. Sidewalks that are outside the 20-foot-wide fire access area can be conventional section thicknesses. 6.8 STORMWATER POND MOUNDING ANALYSIS 6.8.1 General An infiltration and mounding analysis was completed for the proposed stormwater pond by Richard Martin Groundwater LLC under contract with GeoDesign. The analysis is based on stormwater inflow information provided by the project team, infiltration test results completed in the three borings at the pond site, subsurface information disclosed in the explorations, and laboratory test results. The stormwater pond infiltration and mounding analysis report is presented in Appendix D. The stormwater pond infiltration and mounding analyses were completed using the conservative assumption that the pond is underlain at a depth of 3 feet by silt that will restrict the infiltration of stormwater. Seepage from the pond will occur into the sandy soils that exist from the ground �r13�.�� 19 KCHA-29-03:022414 surface to 3 feet below the pond bottom. Water will percolate downward to the top of the silt layer and then move laterally on top of the silt into the surrounding ground. Two stormwater infiltration and mounding scenarios are modelled. The first represents the wet season with a 30-day period of continuous rainfall without significant storm events. This results in water in the pond at a level of 1 foot above the pond bottom (Elevation 374 feet) and maintains that level for 30 days. The second represents a series of storm events that raises the pond level to a peak stage of Elevation 377 feet and maintains that level for seven days. 6.8.2 Potential Mounding The analyses indicate that mounding will occur below the pond under both scenarios that were ' modelled. The groundwater mound will extend outward in all directions, including toward the , slopes west, north, and south of the pond. The analyses also indicate that the groundwater II mound gradient is relatively flat. The analyses under both scenarios suggest that the groundwater mound could result in elevated water levels of approximately 0.5 foot on the face of the slope. 6.8.3 Conclusions and Considerations In our opinion, while it is possible for seepage from the stormwater pond to reach the adjacent slope faces given the conservative infiltration and mounding analysis model, it is unlikely for this to happen for several reasons. The silt below the pond is not impermeable because it contains sand layers and will accommodate stormwater infiltration. The soils below the 5ite are highly variable, heterogeneous, and interlayered; therefore, infiltration will occur along a variety of seepage paths. Also, no seepage has been observed on the slope face at or near the level of the silt layer(Elevation 370 feet) during any of the past evaluation5 of the slope that have been completed at the site. A seepage zone on the slopes near the pond that is approximately 0.5 foot thick will likely not be detrimental to the slope stabiliry, in our opinion. The slope face is well vegetated and shows no signs of instability. Nevertheless, we recommend that the slope be monitored and that any seepage-induced erosion be repaired, if and when necessary. 7.0 SEWER IN STEEP SLOPE AREA 7.1 SLOPE TOPOGRAPHY The vertical height of the slope that the sewer will descend is approximately 35 feet along the trend of the pipe alignment. The slope is inclined at 2H:1 V. However, the sewer will descend the slope on a slight skew; therefore, the slope inclination along the sewer alignment is slightly less than 2H:1 V. The slope was constructed as a fill and the face of the slope is relatively unifo��- TY .= �',,,, vegetated with grass, brush, and trees. Surface water or groundwater seepag along the pipe alignment or elsewhere on the slope at the time of our visit. , - �R3l��GN= 20 KCHA-29-03:022414 7.2 SUBSURFACE SOILS The soils encountered in the boring nearest to the sewer alignment (B-3) encountered stiff 5ilt fill and loose, silty sand to a depth of 4.5 feet BGS. The loose sand is underlain by dense sand to 40.5 feet,the maximum depth of the boring. No groundwater was noted in this boring. Based on our observations and experience, it is our opinion that the surficial soils are generally stable and retained by the vegetation on the face of the slope. However, surficial soils on a steep slope are susceptible to downslope movement via raveling and soil creep. Raveling is caused by surface water sheet wash and rilling. Soil creep is generally shallow downslope movement of the upper weathered soil layer(colluvium). The movement generally extends a few feet below the ground surface and often occurs without a well-developed failure surface. Soil creep is often evidenced by bowed tree trunks and leaning or downed trees. The rate of soil creep may be increased by erosion undercutting of the slope or by man-made excavations that over-steepen the slope. Soil creep can also be aggravated by water accumulation. 7.3 SEWER P1PELINE RECOMMENDATIONS We recommend that the sewer pipeline down the slope be completed in a trench to protect the pipeline and to place the pipe below the su�cial soils on the face of the slope. The surficial soils are subject to downslope creep due to weathering and erosion and are, therefore, not suitable to support the pipeline. Recommendations for the pipeline construction in the slope area are presented in the following sections of this report. 7.3.1 Site Preparation We recommend that disturbance to the slope surface be minimized. Removal of vegetation and surficial root zone 5oil should be limited to the immediate vicinity of the trench. The soils on the slope are susceptible to disturbance from equipment and foot traffic. We recommend that construction be performed during periods of extended dry weather to reduce the impacts of stormwater runoff. 7.32 Pipe Construction We understand that the sewer will consist of ductile iron pipe with restrained joints. We recommend that the pipeline be anchored to the manhole at the upper end of the pipeline to provide additional restraint. All temporary cut slopes and shoring must comply with the provisions of Title 296 WAC, Part N, "Excavation, Trenching and Shoring." The contractor performing the work must have the primary responsibility for protection of workmen and adjacent improvements, deciding whether or not to use shoring, and for establishing the safe inclination for open-cut slopes. Temporary unsupported cut slopes more than 4 feet high may be inclined at 1%zH:l V maximum steepness. Flatter slopes may be necessary if seepage is present on the cut face. Some sloughing and raveling of the cut slopes should be expected. Temporary covering with heavy plastic sheeting should be used to protect these slopes during periods of wet weather. �'�13��G�' 21 KCHA-29-03:022414 Excavations could encounter seepage, especially in the areas where silty materials are present in the slope. We expect that seepage in excavations can be handled by using sump pumps. The pump discharge hoses should be extended to the bottom of the slope so that water is not discharged onto the slope. 7.3.3 Pipe Burial Depth We recommend that a minimum pipe burial depth of 4 feet be used over the crown of the pipe. This minimum burial depth should be measured from the existing slope surface. The purpose of the minimum cover depth is to position the pipe below the zone of potential surficial instabiliry on the slope. 7.3.4 Pipe Bedding We recommend that bedding consist of sand and smooth, rounded gravel such as specified in WSS 9-031 S - Native Material for Trench Backfill. The bedding material should extend to 1 foot above the pipe. 7.3.5 Anchor Blocks We recommend that the pipe be restrained with anchor blocks spaced every 50 feet along the pipeline through the steep segment of the sewer. The anchors should consist of blocks of concrete that completely surround the sewer pipe and that are keyed into the native material at least 12 inches on the sides and bottom of the trench. The concrete should also extend at least 12 inches above the pipe. The anchor blocks should be a minimum of 18 inches wide. The sewer pipe should be sleeved through the anchor blocks with an oversized pipe segment to prevent abrasion of the sewer pipe from contact with the concrete. As discussed below,we recommend that the pipe anchors be penetrated with a perforated pipe to facilitate drainage of the bedding material where silty soils are present along the sewer trench. We understand that this sewer pipeline facility will become the property of Soos Creek Water and Sewer District. Typical details for pipe anchor blocks are presented in the Soos Creek Water and Sewer District Standard Plans. We recommend that the Soos Creek Water and Sewer District Standard Plan anchor blocks be modified to conform to the recommendations presented above. 7.3.6 Thrust Blocks Thrust blocks used to resist lateral pipe loads may be designed using an allowable passive lateral resistance corresponding to an equivalent fluid density of 300 pcf, measured from the ground surFace. An allowable frictional resistance of 0.35 between the concrete and dense native soil may be used in conjunction with passive resistance. Where the pipe alignment results in a downward thrust load on the soil, an allowable bearing value of 2,000 psf may be used for design of thrust blocks supported on dense native soil. 7.3.7 Trench Drains Because the majority of the native soils in the slope are relatively free-draining, water accumulation within the trench backfill should not be a concern along most of the steep hill area. ��13��FS I�N 22 KCHA-29-03:022414 I However,water could accumulate within the trench backfill in the areas where silry soils are present. The pipe bedding will tend to convey seepage along the trench in these areas. Where silty soils are present along the sewer trench,we recommend that the pipe anchors be penetrated through with minimum 4-inch-diameter perforated pipe, installed near the bottom of the pipe bedding horizon. The perforated pipes will allow any accumulated seepage in the sewer pipe bedding to pass through the pipe anchors. We recommend not penetrating the pipe anchors with perforated pipe in areas where relatively free-draining material is present along the sewer pipe. We recommend that the perforated pipe be smooth-wall rigid pipe (SDR-35) or ADS N-12 corrugated pipe. The pipe should have two rows of perforations, and the perforations should be installed pointing downward. The perforated pipes should extend to the base of the slope and be discharged to the ground surface at an appropriate location. The end of the pipe at the discharge location should be covered with heavy galvanized wire mesh to prevent rodents from entering the pipe. 7.3.8 Backfill Backfill placed above the pipe bedding material should consist of the native soil excavated from the trench or structural fill imported to the site. Structural fill material should be free of debris, organic contaminants, or rock fragments larger than 3 inches. We recommend that imported structural fill material have no more than approximately 5 percent fines. Trench backfill on the slope should be compacted to a minimum of 90 percent of the maximum dry density, in accordance with the ASTM D 1557 test procedure. 7.4 EROSION PROTECTION Temporary erosion protection should be placed and maintained during construction to protect the slope surface. We recommend use of straw,jute matting, or equal as temporary erosion protection. Following completion of the pipeline construction, the slope surface should be restored and protected from erosion, and the vegetation should be re-established. The slope surface should be mounded up slightly over the sewer pipe trench so that surface runoff does not become channeled and flow along the sewer alignment. We recommend that organic soil or surface strippings be spread over the prepared slope surface approximately 3 inches thick to promote re-vegetation. The surface soil should be tamped in place with lightweight, hand-operated compaction equipment or track-walked with a small dozer operating up and down the slope to achieve a moderate degree of compaction and a texture appropriate for seeding. The disturbed slope area should be covered with an erosion mat to protect the surface until the vegetation is established. Erosion mats are available with jute, straw, excelsior, and coconut fibers; any of these can be used. The mat should be placed and stapled as recommended by the manufacturer. ��13��I�,N= 23 KCHA-29-03:022414 Application of the re-vegetation seeding may precede or follow placement of the erosion mat, as recommended by the manufacturer. We suggest that the re-vegetation seed mix be selected by an experienced landscape professional. The seed mix must consider the time of year for application,the steepness and direction of the slope, the available light, and soil conditions. No irrigation should be planned. Maintenance and reseeding as necessary must be anticipated until the vegetation is well established. 8.0 SITE DEVELOPMENT 8.1 SlTE PREPARATION The proposed building locations and associated hardscape areas are within an open field with a slope grading upward towards the west and south that is landscaped with grass. Site preparation will generally include stripping and subgrade preparation to prepare the site for grading or fill placement in order to establish the required ground surface elevations. These activities will include removal of vegetation and undesirable material, including stripping of topsoil, subgrade preparation, and site grading. Recommendations for these activities are discussed below. 8.1.1 Stripping and Grubbing Stripping and grubbing should include the removal of vegetation, organic material, and man- made debris. Based on the explorations, the organic material (roots and wood debris)generally extends to a depth of 6 inches. The actual stripping depth should be evaluated based on observations made during construction. Stripped material should be transported off site for disposal or used as fill in landscaping areas, provided it meets the requirements for common fill. 8.12 Subgrade Preparation After demolition and removal of surficial organic matter, site grading should be completed to the required elevations. Based on the results of our explorations, we anticipate that unengineered fill consisting of silty sand and sandy silt will be exposed at subgrade elevations over most of the site. Over-excavation and replacement of the unengineered fill will be required beneath foundation elements as described in the"Foundation Support - Shallow Spread Footings" of this report. Beneath floor slab and hardscaped areas, over-excavation and subgrade preparation should be consistent with that described in the "Concrete Slab on Grade" section of this report. I, The exposed subgrade outside of the building area in hardscape areas should be scarified to a II depth of 12 inches, moisture conditioned, and compacted to a dense and unyielding condition. Soil moisture should be maintained within 2 percent of the optimum moisture content to achieve the required compaction. Following compaction of the subgrade, the exposed surface should be proofrolled with a fully loaded dump truck or similar heavy, rubber-tire construction equipment in the floor slab and ��13•J��GN' 24 KCHA-29-03:022414 paved areas to identify soft, loose, or unsuitable areas. If soft or loose zones are identified, these areas should be excavated to the extent indicated by the engineer or technician and replaced with structural fill or stabilization material. It should be recognized that the exposed subgrade will consist of silty sand and sandy silt with a high fines content. The subgrade will be moisture sensitive and will deteriorate under construction traffic loading during wet weather. If earthwork construction is expected to extend into the wet season,we recommend stabilizing the improved areas by either over-excavating the area and constructing a 12-inch-thick gravel pad or stabilizing with cement-amended soil overlain by 4 inches of crushed rock. 8.1.3 Site Grading Fill required to raise site grades in improved areas should consist of structural fill as described in the "Fill Materials" section of this report. The use of on-site excavation 5poils as structural fill will be dependent on the material composition and weather conditions. We anticipate that some of the on-site material will be suitable for use but will be limited to use during the dry season, provided deleterious material (such as wood debris, organics, and man-made material) is removed. It will be prudent to provide an 18-inch-thick cap of imported structural fill over areas where on-site soil is used as fill to protect it against deterioration during wet weather. Fill required to backfill over-excavations beneath foundation elements and floor slabs should consist of imported stabilization material placed and compacted as recommended in the "Fill Materials" section of this report. Fill in unimproved areas,with slopes less than 3H:1V, may consist of common fill or on-site excavation spoils, provided deleterious material (such as man-made material and large, woody debris) is removed. Common fill placed in landscape of unimproved areas should be placed in lifts with a maximum uncompacted thickness of 8 to 12 inches and compacted to not less than 90 percent of the maximum dry density,as determined by ASTM D 1557. 8.1.4 Temporary and Permanent Slopes We recommend that temporary slopes for construction of underground utilities and basement excavations be inclined no steeper than 1%H:1 V. Steeper utility or basement excavations will need to be supported by shoring. Permanent slopes should be inclined no steeper than 2H:1 V. 8.1.5 Subgrade Evaluation Exposed subgrades should be observed by a representative from GeoDesign to evaluate whether the conditions are as anticipated and will provide the required support. Where pavement or hardscaped areas will be constructed,the exposed subgrade should be evaluated by proofrolling. Beneath foundations and during wet weather, subgrade evaluation should be performed by probing with a hand probe. 8.1.6 Surface Drainage All ground surFaces, pavements, and sidewalks should be sloped away from the structures. Surface water runoff should be controlled by a system of curbs, berms, drainage swales, and/or .R3��t51�,�V 25 KCHA-29-03:022414 catch basins and conveyed to appropriate discharge points. Roof drains from structures should be tightlined to discharge into the stormwater collection system. Surface water should not be discharged into subdrains or wall backdrains. 8.2 EXCAVATION 8.2.1 Shallow Excavation The soil at the site can be excavated with conventional earthwork equipment. Excavations should stand vertical to a depth of approximately 4 feet, provided groundwater seepage is not observed in the trench walls. Open excavation techniques may be used to excavate utiliry trenches with depths greater than 4 feet, provided the walls of the excavation are cut at appropriate cut slopes determined by the contractor. Approved temporary shoring is recommended where sloping is not possible. If a conventional shield is used,the contractor should limit the length of open trench. If shoring is used,we recommend that the rype and design of the shoring system be the responsibility of the contractor,who is in the best position to choose a system that fits the overall plan of operation and the subsurface conditions. All excavations should be made in accordance with applicable OSHA, local, and state regulations. Open excavation techniques may be used for temporary excavations for basements, provided that there is space to slope the walls. We recommend a slope of 1%ZH:1 V where space is allowed; if space does not permit, approved temporary shoring is recommended. 8.2Z Excavation Dewatering We do not anticipate significant groundwater will be encountered in excavations. We recommend that the contractor be responsible for selecting the appropriate temporary dewatering systems. 8.3 F/LL MATERIALS We anticipate fill material will be required for site grading, backfilling over-excavations, pavement support, installation of utilities, and drainage. The recommended fill materials are discussed below. 8.3.1 On-Site Soil Fill was encountered to depths of approximately 13 feet BGS in the southwest section of the site and to 1 foot in the northwest section of the site. The fill is characterized by a high fines content, is sensitive to changes in moisture content, and will deteriorate when exposed to wet weather. We recommend against prospective bidder5 assuming that all of the on-site excavation spoils can be used as structural fill. We anticipate that some of the excavation spoils can be used as structural fill, provided construction is completed during the dry season, moisture conditionin performed, and deleterious material (such as wood, organics, and man-made materials) are removed. The use of on-site soil as fill should be subject to review and approval by GeoDesig• `�•.��+N-' 26 KCHA-29-03:022414 I The on-site material free of man-made materials and/or large,woody debris may be used in non- structural areas, such as planter areas or unimproved areas. Laboratory testing indicates the moisture content of on-site soil ranges between 5 and 7 percent. Based on our experience with similar soil, the optimum moisture content is approximately 8 to 12 percent. Moderate moisture conditioning efforts of the on-site soil will be required in order to achieve proper compaction. 8.32 Off-Site Recycled Fill Material Off-site generated recycled material should not be used on site without approval from the geotechnical engineer and acceptance by KCHA. The use of recycled material will be subject to performance criteria, gradation requirements, and hazardous material testing in conformance with WSS 9-03.21(1)-General Requirements. Recycled material is not recommended for use beneath building foundations or floor slabs. Provided performance, gradation, and hazardous ' material testing results are acceptable, recycled material consisting of recycled concrete may be suitable for use beneath hardscape areas outside of the building footprint. ', 8.3.3 Structural Fill �� Structural fill placed for general site grading in improved areas should consist of dean, '� free-draining granular soil (sand and gravel)that is free from organic matter or other deleterious and man-made material,with a maximum particle size of approximately 3 inches and a maximum fines content of 5 percent by dry weight. The use of granular free-draining material will increase the workability of the material during the wet season and the likelihood that the material can be placed and adequately compacted. Imported granular material used for structural fill should be naturally occurring pit- or quarry-run rock, crushed rock, or crushed gravel and sand and should meet the specifications provided in WSS 9-03.14(1) - Gravel Borrow,with the exception that the percentage passing the U.S. Standard No. 200 Sieve does not exceed 5 percent by dry weight. Structural fill should be ' placed in lifts with a maximum uncompacted thickness of 12 inches and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557. 8.3.4 Common Fill Fill placed in areas of the site where structural support is not required (such as planters, ' landscaped areas, and detention ponds) is defined as "common fill." Common fill may contain a higher concentration of fines and organic matter than structural fill but should be free of man-made material. Imported common fill should meet the specifications provided in ' WSS 9-03.14(3) - Common Borrow. On-site material used for common fill should have an organic matter content less than 20 percent. Fill placed in non-structural areas should be compacted to a : minimum of 90 percent of the maximum dry densiry, as determined by ASTM D 1557. 8.3.5 Hardscape and Pavement Base Course Imported granular material used as aggregate base for pavements and beneath hardscape areas ' should consist of 1%2-inch-minus material meeting the specifications provided in WSS 9-03.9(3) - Crushed Surfacing Base Course,with the exception that the aggregate should have less than S percent by dry weight passing the U.S. Standard No. 200 Sieve and at �east two mechan+c�lly .�l_��UC�il�i� 27 KCHA-29-03:0224!. fractured faces. The imported granular material should be placed in lifts with a maximum uncompacted thickness of 12 inches and compaded to not less than 95 percent of the maximum dry density, as determined byASTM D 1557. 8.3.6 Trench Backfill Trench backfill for utility trenches should consist of and be compacted in accordance with the specifications for structural fill in improved areas and for common fill in non-structural areas. Trenches within the right-of-way should be bedded and backfilled with 5/8-inch-minus crushed rock meeting the specifications provided in WSS 9-03.9(3) - Crushed Surfacing Top Course. 8.3.7 Stabilization Material Stabilization material to backfill excavations beneath foundations or soft subgrade areas should consist of permeable ballast and should meet the specifications provided in WSS 9-03.9(2) - Permeable Ballast. Stabilization material used to fill over-excavations should be placed in 12-inch-thick lifts and compacted to a dense, unyielding condition. 8.3.8 Free-Draining Material Free draining material used in footing drains and in wall backdrains should consist of granular material that meets the specifications provided in WSS 9-03.12(2) - Gravel Backfill for Walls. 8.3.9 Underslab Drainage Gravel The underslab drainage gravel should consist of 1%2-inch-minu5 clean crushed gravel with negligible sand or silt (W55 9-03.1(4)C -Grading, No. 57). The imported granular material should be placed in one lift and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557. 8.3.10 Water Storage Aggregate Material used for water storage aggregate in pervious HMA pavement and in the Grasscrete pavement should consist of permeable ballast meeting the specifications provided in WSS 9-03.9(2) - Permeable Ballast. 8.4 GEOSYNTHETICS If any geotextiles are used on this project, the geotextiles should be installed in conformance with the specifications provided in WSS 2-12 - Construction Geosynthetic. 8.4.1 Stabilization Geotextile If construction extends into the wet season, stabilization fabric should also be placed in paved areas between the exposed subgrade and granular fill or base course. The geotextile should conform to the specifications for woven soil stabilization material provided in WSS 9-33.2(1) - Geotextile Properties,Table 3 Geotextile for Separation or Soil Stabilization. 8.4Z Separation and Drainage Geotextile We recommend using a non-woven geotextile material below the slab-on-grade gravel base layer and the water storage aggregate in the pervious HMA pavement and the Grasscrete pavement. The geotextile should conform to the specifications for non-woven separation material ��13��V��GN" 28 KCHA-29-03:022414 conforming to the specifications for Class A, underground drainage material provided in WSS 9- 33.2(1) - Geotextile Properties,Table 2 Geotextile for Underground Drainage. 8.5 CONSTRUCTION STORMWATER CONSIDERAT10N5 The site is located at the top of a ravine, and surrounding areas on the south and east drain towards the site. Grading during construction should be completed to convey surface water away from construction areas. The soil encountered on site is high in silt, which will be difficult to remove from stormwater using passive systems, such as sediment traps and ponds. 8.6 WET WEATHER CONSlDERATIONS This section describes additional recommendations with potential budget and schedule impacts that may affect the owner and site contraRor if earthwork occurs during the wet season. These recommendations are based on the site conditions and our experience on previous construction projects completed in the area. • The fill encountered in the explorations is typically silry sand and sandy silt. The fine5 content of this material is high, and the soil will be susceptible to deterioration during wet weather. Material below the fill is lower in fines content and will be less susceptible to deterioration during wet weather. If construction is completed or extends into the �tie� season,we recommend stabilizing the areas of the site where construction traffic is anticipated using either a gravel working pad or cement-treated soil overlain with a 4 �ncr layer of crushed rock. Additional Best Management Practices will be necessary in cement- treated areas and to monitor/manage the pH levels in stormwater discharge. • Site soil will not be suitable for use as structural fill during wet weather and imported fill will be required. Imported fill will need to consist of non-moisture sensitive material composed of sand and gravel or crushed rock material. • Earthwork should be accomplished in small sections to minimize exposure to wet weather. • Excavation or the removal of unsuitable soil should be followed promptly by the placement and compaction of clean structural fill. • The size of construction equipment and access to the area should be limited to prevent soil disturbance. • The ground surface in the construction area should be sloped and sealed with a smooth-drum roller to promote rapid runoff of precipitation, to prevent surface water from flowing into excavations, and to prevent puddles from forming. �DE51GN- z9 KCHA-29-03:022414 • The building pads should be surfaced with a 12-inch-thick gravel pad consisting of stabilization material as described in the "Fill Materials" section of this report. This layer will help protect the pad from deterioration under construction traffic during wet weather. The protected area should also extend outwards from the building pad a sufficient distance to provide stabilized access for construction equipment around the perimeter of the building. • Additional excavation below planned foundation subgrades should be anticipated in order to construct a 2-inch-thick lean mix concrete rat slab or to install a 6-inch-thick layer of crushed surfacing base course to protect the foundation subgrade from deterioration. • Installation of sumps within exca�ations may be necessary to remove accumulated stormwater. The sumps should be located outside of the footing footprint and installed to a depth sufficient t� lower the water to below the excavated subgrade elevation. • Construction of stabilized access roads using non-moisture sensitive material and geotextile fabric to provide separation from underlying soil should be expected. • Increased handling, excavation, and disposal of wet, disturbed surface material should be expected. • Protection of exposed soil subgrades and stockpiles will be required. • Heavy rainfall can occur during winter months and can compromise earthwork schedules in this region. • In general, snowfall is not dramatically high; however, frozen ground should not be proofrolled or compacted and fill should not be placed over frozen ground. 9.0 OBSERVATION OF CONSTRUCTION Recommendations provided in this report assume that GeoDesign will be retained to provide geotechnical consultation and observation services during construction. Satisfactory earthwork and foundation performance depends to a large degree on the quality of construction. Subsurface conditions observed during construction should be compared with those encountered during the subsurface explorations. Recognition of changed conditions often requires experience; therefore, GeoDesign personnel should visit the site with sufficient frequency to detect whether subsurface conditions change significantly from those anticipat��± and to verify that the work is comnleted in accordance with the construrtion drawinqs anr± specifications Observation an� ia�oratory test�ng oi t��e �,rup�se�i ii�i matenals sr��u�c� �e compieted [o venty that proposed fill materials are in conformance with our recommendations. Observation of the placement and compaction of the fill should be performed to verify it meets the required compaction and will be capable of providing the structural support for the proposed infrastructure and buildings. A sufficient number of in-place density tests should be performed as the fill is placed to verify the required relative compaction is being achieved. `�•��I G��= 30 KCHA-29-03:022414 __ 10.0 LIMITATIONS We have prepared this report for use by Vantage Point Apartments LLC, King County Housing Authority, and its consultants in design of this project. The data and report can be used for bidding or estimating purposes, but our report, conclusions, and interpretations should not be construed as warranty of the subsurface conditions and are not applicable to other nearby building sites. Exploration observations indicate soil conditions only at specific locations and only to the depths penetrated. They do not necessarily reflect soil strata or water level variations that may exist between exploration locati�ns. If subsurface conditions differing from those described are noted during the course of excavation and construction, re-evaluation will be necessary. The site development plans and design details were preliminary at the time this report was prepared. If design changes are made, we request that we be retained to review our conclusions and recommendations and to provide a written modification or verification. The scope of our services does not include services related to construction safety precautions and our recommendations are not intended to direct the contractor's methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. Within the limitations of scope, schedule, and budget, our services have been executed in accordance with generally accepted practices in this area at the time the report was prepared. No warranty, express or implied, should be understood. • ♦ • We appreciate the opportunity to be of continued service to you. Please call if you have questions concerning this report or if we can provide additional services. Sincerely, �� ,'1. GeoDesign, Inc. �11��} �,,�,,r;Cr� �i„ .. . - `a<.�'� ,ti. _ j.,�, �7'� �j `k'(�� .,t ;� ,� - / � � -��. Thomas A.Tobin, P.E. � 27951 � Principal Engineer �� i� � ; ..,,:�� ` N `'�t�n�� 1'�-`� . Signed 02/24/2014 ��13��V�(G(V 31 KCHA-29-03:022414 _ I REFERENCES American Society for Testing and Materials, 201 1. Annual Book of ASTM Standards, Vol. 4.08, I Soil and Rock {1): D420-D4914, Philadelphia: ASTM. ��, Booth, Derek B., Kathy A.Troost, and Aaron P.Wisher (2007), Geologic Map of King County, Compiled March 2�07, GeoMapNW, scale 1:100,000. International Building Code, 2012. Johnson, S.Y., S.V. Dadisman,J.R. Childs, and W.D. Stanley, 1999, Active Tectonics of ihe Seattle Fault and Ceniral Puget Sound, Washington: Implications for earthquake hazards,: GSA Bulletin, v. 1 1 1 , no. 7, p. 1042-1053. King County, 2009. Surface Water Design Manual,January 9, 2009. Nelson,A.R., S.Y.Johnson, S.K. Pezzopane, R.E.Wells, H.M. Kelsey, B.L. Sherrod, R.D. Koehler, R.C. Buckman,W.T. Laprade,J.W. Cox, and C.F. Narwolds, 2000. Postglacial and Late Holocene earthquakes on the Toe�am Strand of the Seattle Fault, Bainbridge Island,Washington. Poster, GSA Cordilleran Section Meeting, Vancouver, Canada. Sherrod, B.L.,T.M. Brocher, C.S.Weaver, R.C. Bucknam, R J. Blakely, H.M. KelSey, A.R. Nelson, and R. Haugerud, 2004, Holocene fau/t scarps near Tacoma, Washington, Geology, 32, p. 9-12. Washington State Department of Transportation, 2012. Standard Specifications for Road, Bridge and Municipal Construction. M 41-10. ��l�l.��V�� 32 KCHA-29-03:022414 N W � � l7 � Printed By:mmiller � Print Da[e: 2/1 7/2014 4:55:59 PM File Name:J:\E-L\KCHA\KCHA-29\KCHA-29-03\Figures\CAD\KCHA 19 03 Vnnni dwg I i�y��,r nGURf i ,.. _ +i�"�i" ' _ �� ; fi �� r � , MTL+�' '' � o O O n tr�*�'"'"" �.+��«��w��G '� !Y�„�,,� �c� � ,� �� .., r�� o ; — . ' � � n� � k�: s� ' ��.�� r �' . � � `�, � a � m C1 _._,�.. �rw� "� .. , ; ...�. . � �t. ,y� _ ; ' m d ._ ...�. , . , . , ' . �f " 3 ' � � d � G � x - � � ) �� o " �� ' �. "� � �' � ��.�aw,,, r �� - � o- � �.. � � 7p � � �` ' '. �1� �" �V � „ � , .,_ ., w. « " � m � � �� , . � � � � �� '+r�*"`- � ^� °° Z� Z Q � �.�"�W � � �o'-� 4�� ' � �,�' y yy� � � pY J��{�, q W r� � � � ^ . �' � � � ^ ^`• � � 1 � � � ��.�., �ib. "y ��.: ,. � W �C1 p D m rn� � ,� S"''�'�+� ��„� ,;. :C:'" "'� y�i ��' ,�.� o _ Z e m � % �� " ��.,• ` `�, �,� �INC � Z '� '� 'M � �� ,�..;.. �� M: {� . � m w , �.,. �p _ �,., �,'� , arr..� ,5...'� ,�'�. o . _ Y i`,.�w . T D fi - • . ' , .. ' 7C R1 . � r✓.v: ' ' . . , ..,., ... " � II �p � � »+ . ��h ��' „�,,.... ��',.d�'�°" � y .i. > �� .�. t� .c."d,'+�' ':�.,;y,.+ *" ... -"".,n... _,.,,,,""'°°�++�++rmJe.,..�:�r�� " � �._ ,.. w r,. .�� "e �p-�� ,,.m!¢ �t � � ,� ,�.•,�` . � �.� . ,,. ...�` , , , , Ti �W a"�� ..� �'a`Y�a4�.��ih 1F"" � p�, p . . '�t „ ry'�� , �-^5 ��.r. .. .;��.vt '��} .�„��y � � 4^�, � W 7C I...,..� ° ,� . , " ..a..,ps�_4.,� .�, �«.. , �$^ PA�.1;� � •J'•. , 1_ ..} .. `a��u" � �i�#�' ,�r°*tiY�'p,�` �" • � ... .S.. �, �i C 2 �'�}al�'Y"w� �"��.�� .�.�M' 9 � r.` ; 'r1 . r .; h; } �1 .g�� ,�� .� _ � �r�'1��h"�� `��L�ty - � *+,� �,, t_... ..� �\ „�� -+., "� ,q�. � x� rA . ,� r ',:r p 70 N '��w.k'{'��' ""��h,' �� ` I w..y�`�� q..., �'� .»;' 5... ��.. ��Y. � 1� �`�.�. . � . � ,p �, ,�,r, -, -� ,�,"�►,»s,�,w �; " py,, •;��' "`t � 7 " � _- � +�, . � o �7 Ei .�� t �k � ,�, '�A��t 4 � �.,�. ,�,. �., .. , R, ^ � .�;'+1� w+.� ��"'�4 �. �.�....+I�► �: � C � .�" �w � f �� .q3�na �,'� ��f�� yy ~, "�'!� ��`aF€. .� '� ,. p�'�-..��, mb�V e Ir' �� ..�.N� � M. 9t �� -11 t ""a...� �" }.,`yY �' ��« ;Py �,� �..' t* MR'r,:.�� r � �'�� !!�� .'"F �� , .+.Mn � ,�' I �p �F.J 4Y� � .� � Li 1. +K'� ' r n �, j�y ♦. sa�I�� `;'.� � ♦ S '`k 4 � -i..t� , � '✓ P�fj'� " y ...# � -'jt � �t�" �aM . �� I f` � F'.�y �v .. 17` �++M�� 'YR"� Y ..J•�� Y�' y�Jy. �T�.s � � � ^1^ � i �°` t "� � ., s i �. � .�`1�" „ r� - �"r .y Y . ^� '�f y�,��'r1�� ` ! , � ��,,R � ,.�y 1 _4 . , r. . . , „ i�y�e� s �..�+'�} at .,,L.•,y�,t.� - _..�#- � ��"xi `.! u.- '� ,r.. n ) ..��T'w"� A* �,�e . , ,r . . �j. 4,q_ . , ... C "�M f qK`r��i+.� � . �",t�� '""�'�Fa'''� '� "&','� °�p�i`� ��i-; ��' ti�� F � ��.:��."�� M � 4 � x�r��,inP -d � .c • . ` D -� r xM�' �-y �d�� '�"R�+^'�`:.�� ,� ':'iY: .a',t J1,., +'�� . �,.y � .;fa,�l" , t �,:^"` «� .° .Mw� I * Y J� . T4�. �.r:. :.^ A','� c:r q �'t�` r S, �.4i'� ��r � � e . ' a. Z '�� , _ � -..,. ,. . . a _ °!�' , .v � �� ;, :... . ,Ms �� .�� '. �s ,�,�,, d , . �',«� t D � �'� , ,�4 ;� ' !� ��° C.�, H . . 'x i^ • c9 �- ['' . . _... r`1:" �¢a i �'� .� r� r S�fi�K�x-. , �'�+! �+�� 'L+� �'� •�a � �*1 �'e' }S. a. i�` �;r r q y�`�„+ w,.r �!, . . r " . .. w�..- `'��ti. -y . , . . .(• '�li . " .�r �•[l[`�F '} �, f Z O .. .s• �'1I 1'� � �'4_ . b.'- � i",�, '�'a r ��i�r 4 ��^ .� § "�* } t'1 .+"1� : A;'. 0 Z �' " * ��l,�r�'�l�� t .� x�ti"�, �� ,�y�'�b"w�� "' Y �4 A,f . � .,t. �`�; �cg7 � � � �x � y . � � Z D < .�. �iI qi,�� ,,,:. ',.y.. A` •1(°^"^,��....�a��,�t �-+ � ..�,x�� ~y . I � a n 'o � �+ ~ "`" � �"- ,;�.�� ;,,,�� , y � Z � �� .�� , w� r' �. ,� �,, ,� .,�, � * � ',� � n ,,,.� ��::�� . . ,�, ��. �� ; �;� — �_.:�.a � r °�.� � ..�.�• � `�....� � � : ^��.'+c�' �� +,�. m � D ,�w. - r �F x""� ' . Z •� r' r � �. �y�� ;q r+ r �j I � m �je �r. �y, � w r .��a.t .,t.7 y `�� . ��. 4 y...3°"' �:� - It� � � � N 3 Z ��^ � .7�l�r,». ' lA ^.��i„'s`w-., .ra �� '�� " � a,,. `+� . , - r' lYa�� : � wr h: . , . � � N � �� p n""� ��.+y q4�+� `t ,,��'�i'"� ' +# 5 C �C a ��`,�'."�,X � y, �Y� �71` . . . . �,. �1l�x� . !�,.+Y ♦.;�U +�. O O Z �� v �t .w�"' �,�'�* t Wui. ;•S u �L:a�C�'w`�'��,;* �`�°,�Y��^�.'�^�-` i , x � ��.�. � � ��'. ,� � , -.�. �y., �� '�r .�:.��7.��;.,�` 't_�"�' y( �t"�� I `� � 'ygn ,.".�.,�r�� P y�� , � .•,� _ �� '. r• � i��.�#•��'�'" �j�� M�� ,�� ^� � � •a .. �. 'i�. m " �'�" A' .+ �' •'�� '�`.��'�= `��. . ' . .•M . , .� � ,,,�� +yw � '�� '��-� �.�7�jrJ �� .',�� f; , � - � , n T ., � � ;�i " � . ,`,; � �;,��e "� ��t ,�'� `�'�� rn o 'nr' *' ,��, �r, �s�"� �' � P ��' ��i�E��y�� °:;�;'� � '1�' f: L.^a�_ Y '^� �:;»�:��7NE`�'"� � ��::'w��.�#�'�.y „r Printed By: mmiller � Print Date: Z/17/Z014 4:58:55 PM File Name:J:\E-L\KCHA\KCHA-29\KCHA-29-03\Figures\CAD\KCHA-29-03-SPOI.dwg I Layout:FIGURE 2 / "\ i // i.��\�\ 1.1 ------ �'/ \ _- --_ . - �� ._- — --._ ��- , � �. /'�� f _'------ � � - � -- - -` i / ��_� � __ � � . - � ,.: . �'- __... ._ .._ . _ ...___�.��..�.� `� 1 �/ \ � ... '__'_ � ' --—` 140 '" __—=—�_� , = � ; TH�VENUE SE ____ ^ ...—� � � ---�__ _ � � � -- __ i• --— — - _ , pp _ , �; /� �� '� ' ��" - ___ �• N/� � �----� � ,�0 �' _ -�„ , ��`` S �� []� �'7�-.�.,,a.�..�� - } ' , �� , ; ��, 4 , ,,. ' . a Ef! ;" ��• �, — �,�f i / �. �,� �. , �. �� - � , .� �. / ,�� .y �- -- - ��=" _ �a-� �� / m..s ; , '� . " .._ � �' �� , - ��.� \ 1� �� .. �r".. � ii��i1/� � �_�-=��-� -f`l� �� i �J � �� Y � � �� ; ,�/ /� ' , , '� � a "�zne ; �� , --,';��,r/i�i/��r��'��_��• % � / /, I ;�/ � � W � /// � ^ _ . .��- . .._C '� / � � ' �€ � �' , ��~� 'P��l�� °j� pC�" 'G � �� / J �i iii� i%ip� ; �� -` _ � / �i�i �� —!"''" � i _�_y i i� //i/ ='� � i��i/� � � -� � A.� � �V � � ��//j�//�/%�ij:��= �_._ � � ��// � 'Q) / / i��-� -y.,� � / / �i.o� iii��iii�� __ ._. � �1�-:_ �.'�. "�\ �`�/i,�� i— -'��'=✓ �� / I ' /�/ i�i //yv'iii��%�� `_ / � ' �--_. rt � n �_' �'`,%/i�': `— �,- ��, i / i i/i�ii� ' _�-�- �— l � i ii� rii ��i�i�� i T , — _� — � / ;�i/7' ii/i�i i �. � . �\`�// '� _ � ,� „ %;�;�r;-, � , , ,- ,. - .o, � � �� //�/�/i �ji"ii%�%%i�� ' i' �� ___ ,' _ _ / i � . _ �-_ _._._ _.._._+I I _ /� ��/��%/�,/,�'.�i�� ; / � � � i � rl -.''�_ i �� ,,;�;o ,;,;�;i�'�!i;�,/' � � !� �� . __=1�! __ �\- _� - _oo �F- � : __'� -Qo 0 i � � ��i��r�i�� pb, � I i �� D n / ��` � _� �p �� ' �, ,,__/ y�, � _ I I �� tt i�i� ri ia�°i�i/r� � � f � � j r^ � ' � --- � '�� i1 �� ci �y� liiii�iii%�;/��ii __ � � t � r i � '^,_.�- -- - -�_ _ pp ;' � �_. �I15 0 l ,%/� l ��,�;��/�� ', , � ( , � '� , � � ; , �1�___. __- , � �p d'id �4, '� ,�I��;;��_ , � � � � , � , � . u,, __ _ __ �+ �� .�_ i l � 37 -� 'h' �� ,rp� ir/r%- - . � � � \ � � , �1� � i ___ 9 � - -- , �' , �I I � �� u�l�'din� e,� � � � � � � � � ' � � � ��---- - � + - i I � I ��r��{r��l l � � � �`� � 1 i�i i ��, l i r ,: �,� C 1 � 1 � �'NI� I Ilrl ll�l� I � \ \ I I I - _ _ - _- �` �� I I�il�Il�lill�//// / � \\� \ � � \ � �� j _:� �.. � . ' � � � I�I I��l��l�l� l � � � \ � A�� I� i y --- , -"r � tnl�, � ��n iii�iqihiii��,�i l i � �� . , , �/�, � �-�_----_-� 1 �/�pEq $ __ _- I _ .�1� .mrp� a�IIII IIIjIj�11III�jllll I � i�^\� \��\M� �1 1,111 ��('�/�/ ' ~ m'" „ _ -� - — ---.. i` Qp,l I p�I� ��\�\�U�1111 1 � � ' -- --. f _sn- — _ _____, ' 9 _ \ � \ ,� � � � � _ m- __ v 6' � �� ii�ui -t�qlii�lwi � � �� \ bL � �i i�ii � _ - _ W--�--.�__, � V1�� E � pn�i iqluil i �i . �, �, � F � `V'�'`� i' � � d _ _ -- --=== • --..�� "', I�� IIIII�� II� � � \ '- � �I�I � ' / � =_ ==_. --- — �� V1�1 � II�II� ��III 1� �� ,� ', �� . � ��A�11�1 � V / /� --�.�'-._ �.. � � ----------- � 1 I II _ � __ � � d �� II fl �1� � � � � v� v � �� I�� / � 1 I� � � �t \1 � ��I 11'lll II � � �� 1 � � '`V � �� 1�11�1 � j � '�I� T � �I � 1 11�U�I� ��I�I��UI� �11I � � �� 1 U�I� I I , m p u,ni n,� �� i i� �i i �. i � I � ,I r„ , � ��,,, „�1„��"��, , , j �� , � 1 � ,� �� i � ��i ', -{�� u i� u ��u ; �i A �� i�i i i � i �J nJ i� � � � i � � � ` � i i �' �� i� ��i�� i i i ii�i � � �i� 11 I '� 11 11 l\\1 \\11�� 11�1 1�1��I I I I�I I I o 1 �i �� I � � � 1 � IIIII � ____—_ —�y---�-- �I �I\\1�11 1�11 �1111' �\ �`� �1 l`I j�I II�III M �� 1 I �� \1 \11 1 �� I II� I ',� ��i i �;'1ia ��i�i � � �i � �� iliiiiiiii� � �i � � �i I� �i !/!� 11�I11 �, � 1� � � 1� I�I��I��I� � , I �� i 1 �i ��IA�� I �� I � I�� (�I�� ) � �1� �I 'I II � i( �(�1� 111`1��1' u !I I II 'II �I'i II i I i c � I \ 1 ��11111 1 t� 1 I I II I �I � ` 1�� \\�`�� 1 11 \ � I I 1�� I�I�I� i y I �� `�1\�NI�1 �i I 1 � I � I��I�II y Ti �� \\ �\\�\\\�� I�I I I�I ! j - 1 I� I �I ��\ \\\ \� i�� II l i II � i �1 I � � 1 b� ��\�a'1 �� ' ,I�- ', �� p��`\ � �� i i ',i I i i',i u;i � � -` ,;' i; � 1 � m �� \��`\L\\\\I I � I �I II��I�III� � �I I� � � \\ �;)\ \,,\11 \�\�\`+ I I i I I I�i I I I I I I� ' �� / /� \ \ O� � \�� I �I I � I IIi� � I I i � � i ii i E i� � ii S� /1 � � °-�. �� \�i i��i�4 ii i ; ii ;� lit \ � '��o �� ' ii�i�i ;� � ' ' � :i i� � , ;l � � � � � �,�i�i�i�i i� � � � ' i � �� ``r� ,,. � �� y��In� � � � �� II �.! : �� \� ��1�11�111� � .. � �� 1! �� ' O .. + �,� ''�!`�'�� '•� o s"� �' II �y \ \� �111 I� I i� i � �.�e �\� I/ 1 1 1 --- — 1�� _ � � �� '1�1�1 I �� — �� +��^�j� � �. � �/ �I �', --- —./� ; i� <'^, , ,� , �' II `.F \. ��,� �+ �1 � I� � � I I `� � �% HS �� f� � I �� ` l � I� � �/ /1 I � \ . ` 1� 1 I S --..�___ « ,� , __ ____ i. � � � - ,- . � �,� ��, I � � � ;�� , � I � \ \\ I I �SD D . I � 1 f� � lp , � � I � � � J � ' - �� _ , _, , �� --- --��._�-_ � � .�_--_- ___� ��i,'��,^.�\\ � Printed By: mmiller � Print Date: 2/17/2014 5:03:06 PM Flle Name:J:\E L\KCHA\KCHA 29\KCHA-29 03\Figures\CAD\KCHA-29-03-SP04.dwg I Layout:FIGURE 3 M ♦� ! .;.'}* ..1!1'+'�� t:��. ��• .. �� .(:y ,� ',��y� .. ' �'' � � ..,!}�* ,� �� . ,� �r �S �1� ..Id�� w �r � �-I� M � * '.n .. ' � � +f i� .,., . ^ �� .. � � � . 1�' . ..,_ ti � '�� , �I�1��: ��, :��' ! .r' \ * ., �� , . �Y Il�„c . �� , �. �. - �w . I � ' .. �: . . r. � . f �` �P. ,i I� 'a, . •'• P ' ' � ' Y' s ,,+ � �ra�� ;� ,.. ,� ,;;. :'k� � ., . .. . �M � �x � i , �� , �� "�' �* � �a A � F�+ �� .yk f' , x�, . � � � +.`'�+`.'�'r. k. :{ ,. -y� 1� ^� r 1 � l y�rtJ.h�l�' � � . d� " : .' �� '� �t��#^ .� � � � , � f'�' ., .r « "', d'.. ,; -� .` h 4t, ,� , s .�'.4�� al, 3'w'�k..�. . 1. � � X �' . � /'. . a h� �- . t � ,y' r • � � '� � -�"? " PA �r � � ' ��'� n �. .� �.�: � 4 ? �i � ' � � w • .... ��` � , o i � ' ^�� -w� . � . � r� � � �... .� • '�� , . i,.,� �; . �... �( ..e. +'� .,� . (r ,t !. � ; � . , ,*�r`"✓._ �,c�"'t" F�� r ' " � . ' .� �.V...4N J�.�, �' . �� riM� � � Y � r � � �.��.y, �5��11��"J9►�..,� :r �t .��,� ,� • kf tw ui� • � p p • ,�' .. ''� 4fi"i 'i�, i,r. J , . ,' "/`, .. • i .. � � �� y�9 � .� � �1 � �v' � , 4;�t� �p� ''"�, Y � '„� • S� �'� ��,�i, ;�i�� . � � M �' ,.d"'i'i1l� �� '� i � � "nWli'�t ,�1� °T. e K , . ' . ��, y a u, � � � - � � '"�., + ��:. ,+ ,�, uy .�, 1, ,�i'`� . . '��'i �� ,� ' ��4 - � `F � �, � . . t ~ i�4 � , i �r� . .. u M�i'�"' �" ) Y. .r' Q!, . , � � IM' " , , V �'i�± „W' ,.� {��.fv-, . . '.{ti. � �.i . S . . r',:� j�v:" � •'"'� � i�. ( _ • r` ��"�' k' �,�"a �: �} ,� ' `,� tR.` �` , " ,�', N ,°y a, � �. � ��F ` � + r''�,S ti � '�e, �., ,� w_ �'� �,.� •�, � �. � ,. }�. .,,• � �'��, i ��. � � :�� '� �,; N � .�,. �� . , n' ,�,,.�,� " �;y� . , � „� , t j� i� : � ,r ' � +� � , i� �y,, �; �y�" , �t��. �"'��; :n „�.. M�� '!� O � �"�� tin u. v 'Y. � ��r"" �yt+1"� .. � ��.R� ��. df'.. , ��' '�, f� � �� '! 1�� p �'`;C'•,',°'�k.� u i .,,rr e^;�, •R � ��,, .» _ �.:i 1;� ,� '�'+ry��' 'r .�' -. .. � , A M � ` .V . S ` �,��"..'� � . 1�J,�.� � �, ,{'.~ f� � .��i �t . � A ',� �;, 1�3 .� � ,n � .� , , . • v `-� �',;;. V +,, , �� ,-r;f , .. ` � � ' ,u -O �� ' � � ' " I'� ' � i,� M � � � � 1� `✓':/I' . .�. . . " �`� �./� �. � � � � �� + 1 .. 4 ' ' . , , .. � t� . • '�� . �� ,� �S � ` � ,� , � �M �� ,�� _. . � . .. � , . , . �, , � ...,. N � � �y .�_,.1 yp�� , A'.' _ y ��'�"�� , o °r� k�� ' � R' :� W�1 � �"� �� . � , .�"°' ��F�� ,,..---.' ,,.,� �. ��z..a � ��`� � -, � /�a . . . � �ti , ,�,•,*. � �1,•,; �t .. •��,,,�N.. . � , � � ,v .'• . ,* . �.a�:T�- _.}. �' � ,� � 7 � � A `u �''�. , �,_r ,� f�';� � �� .i� � �, � i;; � , ,., , ;�, �. ��z� �� '�' t�.., �; ! ':i. , m � 1 � � z. ��j� , '° '' ' : #`�` � ., � � � �„ ;�" �� . �� A�i�: ♦a '� i�r^ `` � y • r}' I1 f � � � irA S nr ��`"y�f� ` ,.i ��,,,,4� t, � �n, F , . � �, . :J i�'l. �-;.�—� ,' �� -jJ'y� *''� ^� . ` �""�: r � � � � , ��■ �. '1� ! ..��' .'. � '4�. "�� „ 7 I ! .r'�. . . . yT��. .y.-. .1.�� ` ;;+. � rI �W�'^��#'r. t ..�� .� � '��`�•�+�� . � � � ��., ,�r�" .,,� �' '�`� ` r ' ++ � � � �. ,,. � '}� ''� .�, ��,.' � �'f ^� �"'' ;w � �'�,: � ;.''. r�;�� .�. �' ..,� � �, �-t iMi . �'� � . -- � ar :�.. ti '*" �� `� 't. t ,, � �..�t•. .�..,' v� • � , . � ry� � �. � � _ ` °r' 'F ' �hy�. ., w.� , �.`��+�• ,� w — �.�' . F�, '�� \ r' t ,t . -��;,, � ' 1r �`� �..,.,._ ' .� ..,, � m �,� � r��. � a�, . ��y �� •� w � �,y' � �! �. • � L .•X ��" . . .. �'� - � � h ' w • �� .3 t �'�' b � � ,� � �u 1 ;, I �� . + I�:i �i 't 'ti � � �� .�� f . .�. � -.� � . ;� :'� �t4� r b •t�. ',r +� �"- r,. �" : "'� ,j .� �' � `r ..� � .y A t;. � = y � � I .. . - . ' � � �� ►.�.+r�':' � pr� �� Q � , ..tf•� � ' y"': �C..��.�� . �Wr.m� J �'�l � � O � �`. ��n' i .. �; . '1F ' Y� �� J T Ll � _.._ . • - � y { �• - `" v '" ��: � = o . _,� =�� .,�,� '�VcY' ..' ` ,�+� D � � N �.� . �,�., � � � .wr" � �� n •r � O D �k �^` �'` �1'�� ' �' ' y, � Cl m ..._.' ..�. � 1.10' {�� 20 �, � .. . '� � '-'.' "`r, � � 4.`� D Z -..� . �,�..,4 � � f, � �. n = D ;�_,,, �;'�;t • : �;^ ' � �v ` � S "� z O � � �L+ ' ' 3 ,. : � ° v � O � ' � •.�Y• ` ,y . `Rk,0��», t ' i�'S �� 1 �� = y ,� o �3 • _ ��,,«��.,,,,,,� �,,,+ �2�� ' 4 .; +" O m D N ,; +. . " "'��!��..., ' � a4r y�1 S � ��Q O � m !�• 1�+'. ' . .AM'' w��`��,�° ['� y '�,�, �, � x � �° � ^, ", J�r l ' �i �� , '�.' � ' 'i ,. r+� , . , t ' . 2 � J � ,+� F � �` ., ' � � f, r • � T p _ ..• . _ - � ,; � � , � V+ 7p p . ,y r� � •_•.• _ ,,,,e,.+.�''�. .:,� �,,, �' ��; `�� i,' ' �Y � 0 , � •. . . .�' '�"�' '� _ _ �a � � � � !! � ' '� '"':,��. ♦ �'� ♦ � �� r` • , � .•' � � in. ,w. .�'� ` Y1 I� ,: , ..�: n �.... -�. .. � . ' �� '�� i „�}` - �,-:. . � + �+�..:r,.' y � " I� N � � . ' y,.,,I i.��'� •�� 1� I� ��r�,�'.. � � � : ��. •'�Y ��. :a.,:q.. f1 � b-a T � •r , ► . . tn � �' , F. .� ,,.�_� � �� i ` -♦ ,.':?+t�.;". . .. � � ��^y";� `.��I;� �M� �DESIGN? KCHA-29-03 1985 AERIAL PHOTOGRAPH OF VANTAGE GLEN SITE 10700 Merldlan Avenue North-Sulte 210 Seaetle WA 98133 VANTAGE POINT APARTMENTS OH 2O6.838.9900 Fak 206.838.9901 FEBRUARY 2014 FIGURE 3 RENTON,WA Printed By: mmiller � Print Date: 2/17/2014 5:01:57 PM File Name:J:\E-L\KCHA\KCNA-29\KCHA-29-03\Figures\CAD\KCHA-29-03-SP03.dwg I Layout:FIGLIRE 4 _ � �/ //' — --r Y �� \ I ��`�� / '' � — — � '"' " `— -^'— _1ti_ --".� -'' � i ii '/i/�\\\\��/ ��/ �-"'—_�-- � � — — — — ---^� '�� /// i `��` � �! � � \ ///�� //��j " — _s—_.—a�_'' ' ' � � \\` N�� ' � � _ � �' - s' � /j i . '_ - �, w_. \�\\\�/ �/ ��' � `J / i// / / ..— _ �'t� \ .� _ :- as . � ; �\ � [� � --� / / _.� ' / � � _ � -� � �' r ,�;5� i� . � �� -�-_ ,� � d� ii�� / �,ii � � '��: �� 1 i = D __-.., -� ;;, �l��i��i i< . � �- � -- � ,, � a , > i/ / °� ��°O n _ - � � � � r �iui�r,� _- '� �� IJ �, ,' r -: "- _ i�� _ _ / i � ' � i ✓ � / - � �� _ �. 1 .,. i � � , . � / � - - _ ,:_ :. � _ � /, � ,�, _� / / � r / � �, _._ ; . __ _. - -, i � , ,/ - ".,,� �' , .. - i / -- � ��, � ��' � i� � j'` �� -� /, " - �- /� � %'. > i � - ; I �' , ,„ �� ;� � � _ - _ ' _� - - �,, , : � - _ 7 u , � � � �� i __ _ � I �/ i i�ii �� ;< / 1 � - � � �� -� - - � � � I� .l , � ; �;,,;,,, , � � , � .�� I �` ;�� --_ - _ - _- - I �� /' , '.��;�� , , ; � i D n . � , � _ ,. � ri ii� ,��y�, _ _ � m � ,� , �� _ ,_r �11 ,� ��i i, �r�ria ,',;ii -� r � � r __ - - _ _ _, - �. 1 � � ;, ��ii��- '� � i � � � � 1 �� _ _ ' �i� �i '� ;�" �;��,� ��riir . � � � � � , � � , _ — -- I � �� ''�;;i�n� i/�� i i i --- �- � '� I I� III��I I1 4w� \ � �� \I I� I I� I� I r '�! I�y�l lh � � � �+I I I � � J �I � � � II�j��i p� ll�l llf 1 \ � � I l � � / I � � � �I II�I lI i ; A � A � V �� i ,�� '� � � I _�._._ � � � � .�' � �� U II��II��ll i � . �. � \ � A �� ) � � i,� - _ � I� �� II� � � \ � ��',� �.-...----- -- . � _� �� ,�, � � �� , ; �, � -� 105TH PLACE SE ., �� 1 I i i��jl �I I ., � � I� i� - _ �-� � w � — - �� II I�I i ��Il��lill � � I A � � D'? �� I�� I�l� ' �� • ---��ro-��-� � sn �� "� � sa � 11 I� � �1� I I�� III I �' � � � �y �I !� ,�; —— — — — — ------- \I �� I � �. � � \\ \1�1 �'� ,. ". .� — =_-== — � — — � 1 �II 11�1! 1 I , � \ \\ \ \ � ��I I � � / f —�. `_ • : — --- � !I II I 11111��I II'll��\\1�'111` � I� � \ \ \� \� ��\ I III � � I l�l I� � 1 1111 ��I� III1� I , � \ � � \ 11� � ' I � �� ' II 11 I ��II��1 111 � � � �� \ �\I I 1I��I�I I I , I� 1 � 1 11� 11 1 � \ � � II 1 � � I � �� 111 111�� I I � A I 1 1 � 1 �U�1 ��1��A1VA� �I�I � 1 � � ��I�II � � � �I� 1 �1�� I�I V11�II�� I I � � \ �� I �� I 1 �I� �� i� �� i,�� i�t!�� i� �i i i �� i��i i �i � o ''� �i ;1 q —�y---�— ��i�u ��u�i iii � � �� i �i �ii�ii i �� '�1 '1 III 1��111� 1��1 1 1� \ 1 �� II�I� � I �� . �� 1� I III��,11 �`�V I V 1 �I 1 I � � I�� 11 i I II�III��. � � � �1 I�IIII� � j �� I 1 ;i;/{r ��1�,��1 111 I '� 1 I � 1� I I III�I � ��I �I � I1 � � \1�11� 1\1\ � �I �� I� � �I�I�I�I�I IIII I � �� II �� I � � 1�� 1��A� II 1 � I I�II � � � � � �I � ��1�� 11 �I I� �1 � � � ��I I �I I��I� �� i �� A \`�` i� � i i iii iiii � � i ii � � V �,�\'�'�� ; � , �'�� , � � � .�� ; � „� ,, i i � iiii � i i � � � � �� \�� ',�, , �,�� ;� � —1 ''� �� , m = i � ��'�� i�� i �i ��i��i n �� i; �l l,''' .� � � 4, �� l � � '� � '�I��' � ' � I� �� , � � �� ,� ,��, , �n � , `�� ` �� i �i i �� i� i � � �ii n i� � � � �� ``�,` � �� y i � n1 � �� n'i � 11 \ ��` �� '� �I I I�,I I� I I m :� �� Z �I II \ \ . �`�:�.- Ihll��l I� � � i �I � �� , � � �-� �, �" �� I��, � , p r > � /� � � r ,�< ��y �',I',',�,''� '�'� ` ,I` �� ; � � m _ �=, � ,4� , ��. � , ��;�'� � � �, � �� , '� Ir \ \ ` ' D- - I—� � � ` ��I`1 I 1 r^(l-I i� j� � — — - �� —�0, � ��•li �� i ;N ��". -; p�� i� j� �\ � � �, ,� �i �� ,z� � i I � \ m �'` �� j\ Dno � �� \ \ i' 1 ��o I \ I T I �� "+� � � I' S _ ��T '' \ ss------�-. �=O �ss '� ' �o0 �.. � � � ' ! i � OS� m I1� � � J I � �i� i N�v � �'��'" O< � �� . �� C �� J�� Zm I w on \ �� I N . D /� ` �-_:__—r.__:-_=s_-�3-—-G-_ T /�\� — S r / �.\ � ". '�., - - - - - - -' , �n ------- z� ------ ., �v o � � �� z= � � �, , ' I �y z O o� I � ' \, O n D m �' ' � _ �+ � �Z n - - - - - - - - - - - - z C1 m � ° m = 108TH AVENUE SE o� Z o —=�— v z o z �_ _. _ -�- v"' n � T - - m C1 m m - - n� � � - �� n � �v � � � D� 0 � n+ �m � O �^m N v �� 00 Z � �DESIGN? KCHA-29-03 SITE AREA MODIFIED BY PREVIOUS LEGAL GRADING 10700 Meridian Avenue North-Suite 210 Seattle WA 98133 VANTAGE POINT APARTMENTS Off206.838.9900 Faz206.838.9901 FEBRUARY 2014 FIGURE 4 RENTON,WA Printed By: mmiller � Print Date: 2/17/2014 5:02:12 PM File Name:J:\E-L\KCHA\KCHA-29\KCHA-29-03\Figures\CAD\KCHA-29-03-SP03.dwg I Layout:FIGURE 5 �- - - --�' - - � , . � � ` < y / Y� \ I ,�'%��`;�C� �� i''' — ----=--=__—�1_---_-_��` ' / /�'j/ /�\\ \\��/ //��i/i��__.�=====��_�=—�===----' �I ' // � 1 i�� /i� � m �� / i , \ � r �\�\ N/ /� � \' O � -._ , �� 5 � � ❑ � Q ! � " _��.�'`''� . � � �� ' , � / �� \ � � as QS ;i-��i � , ' �:-�. 1. � \�� / (�� =-T� . _ �..� � - / / '��--r � � � �`ii : � _ � ,,;� � � a.� -r �� / � � � _ � � ` , -� , � / � � / � �/ �� ) -._ � � -_�--` `— — �_ --i� �.. 'f��', �/ /iU��'�i 'o�� r V � / � i ! i D -�. - Jri,�,��f , �, �/ �� -"ry" � �,_� ...y � �--'� — J' �; / ��,��ir�r, . . � / -_ � 1I / �. --'!W m l__,,,— �� ;+_. ` �`' � j ��iii�4+' — ��' � � '' / / ✓ �` � i/. � �"� � _ _ " �'.�-�` -,- ` r `�� J. � l / , . .� X �- ,-_� . �� _ �' i�� i �/�� l' � �� `--�� .� _'�i �-��. -� �� . . 'y � l /� L �/�/.' �__. _ �- . � � r7� � l _- � ` i�l �/ � �� ,�' /" � - �� -_ ��s%� — — - rp , �' •J , ,,,;;�'/� , �-'^_ \� , - ; '"- i.- - J __� � � � ,- , � ; �/,, �� - ��./ � �� J , „, , , ; � � � �� ; iu� .��%i/��. �� i� i � D,� - - _ �-- ---��' _'— �r � -- �� . - , ,, � 1 �i �' i��%i� � � i . � _ _ -r� �.� . . � �,. I I� � ,/ �,'��'�' � f ` i ' D n I �i= ' _� __ - _ I // /�j_ ' � ` m I / •" \ � , �� i�'��,ii �i�r�� ,�� _ � r � � � � � _� __ ___ _` ` � - - , �� 1� ��i" �i i �i�ii�,� i I 1 � � _�- 1� �1 ��j �ll�i��,�li/i/i � � i � � � � � � �� __ _ ___ � � �, �1��1��U�!�l�/;r" � �� j � � j �1 1 _ __- - �.. �'--f. �I � I ! �Iryf�l iili �� i i '� 1 � � i�l��i�i�r��II �� `� � i I�i i � � i � � � / \ � � . J� �1 � I�'I��Iql�N 1IP ! \ �, � � � � � � 1 � %� ✓ � )p � � I ( II1 I °il� �I Iill(If llllll lll ;� / 7/�. \ \ \ � \ � \ \ �\ , .. � � � �II I�I�I'lll��li lrl ' 1 o'!II ��III�I �Illll ! / � � \�� \�\\�\! �) /�i'�/"/� �. ' ._. • �� .._--. . _.. __ . , I � ,I„�� \ , � 1 � , , � �, , - . 105TH PLACE SE � �� i �i�� '�'��I„�iii,im � � � �� '�,A�� ` � � � ��'�� ro�' ,- - - � — - � � i tl� �i ��p111 t � � � � � � ' ---a ro— , ao �� v \ .' ' \ I � 1 1 I I, _ 1 � I �� ,',,,1��„1�� , � � � � , \ �eb �,1 � � �� ^' •_�� . s� —�-- —. _ — ' 1 m� i �,,,iyi ir i, , �� , , �, i i,i i, „ � -_ ... �� 1 in0 `�p�i�nA�n!y �'i �� \ �� iilr��, , ; . � _ -.:=. _ � _ Printed By: mmiller I Print Date: 2/17/2014 5:01:14 PM File Name:J:\E-L\KCHA\KCHA-29\KCHA-29-03\Figures\CAD\KCHA-29 03-SP02.dwg I Layout:FIGURE 6 —. —_. _, _ ________..---- � _._ _ _ ___. I I i I , � 1 � � � -_--�.-_ .. ,-- 1 ��" �1 r-�� y .;.._ ` � .J 1 �J i � � � ��i% ;- �� ___ �_ — � a d66 �%%i,`��="`�� ___ , � , m�; �� _�.� -',,,'/�i� � s�� „ � �� -�� -� -,�� --�� =,'✓'� �;�;%,��4 r-^'� ' � i-.- __1�� w - �-L -T:�i�jr ii��,j llrr //�� 1��.. ' ...- -'ii�� r -r '�" ��.- � iii/%'/ �4lI' '> l'%�- � � _ }��-�- �-�'.'��i�,�1+�' � .�. _ � � � � s J �i �; _ y,� - 3 i � •,,� , ,%,� -_ \ � %/�:' �� -��- - t � � � t � 1 �� I / /i/ %ii �.' �E-; -y,-�_ ' .2'.. ��ri//. �j� ! / i/ i ' �f � / iji �ii�ii,i� .✓ �l�� . .� �1 . �-�_j; �'�i - t � "� � /i/ �/j i,ii ` y 'r •-e��., . / //// l/ �~a_ �" ��/��iiii��i�'�� .-.r' ...__a -sk ..,�,"'. . } S�!',/�/ p �-!i F �/, �ii iii.�/ �.�,c.,� % F�!1' ;/�. 1'� �/� /jj/� ��/��;�'" �' %i ' 'r-..».,,., f Y�>- br i" Y y _... „�».x ` / // ' //%/%//r �. � / "� . J „��% ,,,,��,�� - � , � �n 1- „ „% ,,,,,,,.,, �- , - ~ `. � r�,G �i��iii��;�,,; _ i � �. / � "�-_._"__..c., j i � :.,;•'`'`,`''''�' � � ij i��'"�iiii�/yl,: I � / , --'---,_ ��.. �� , � � i�ri i� i �_`,_ ��\\`_ �� , �. � !��ii�iiii��ri��i; � � �� --, ` .- i �i��/i��i��r/.� �` � _�- r�(/�� i�O��'��i� ` � � � � � -f �__ '� \ i ��ii l'�iiiiiii � /i � � � � � � � � . _ `. M ��1�� ///p�� - -- • �, �4 u� r n��i`u�� '`�� i � i i --- ,�,. --- y �� i ��i�ij�p i � � � � �`� � i i � —__ �t � � �i i�ii u�i��p � I� � � i i i � � , �`-�.. _... -- '_" --- � � �.. � _� I� �hl��II� ;_ , � � � 1 � �. � � _ .._ =.,.,:�� _ � , __-= -...._. �..�:_.:.. ._-�. _ � ��y � ��N� ��i�ur�i�itn�� A ,� � � �� _ __ � - - `" 'i°i,I,,,f"„ 4�i� ----`----_ 105TH PLACE SE �� . "� ea ii iiii iii � � � � � � � , � R!; �Illil� II�`��\pi 1 � � �\ \ 1 I ' / _- rQ'=.. _W_—...._.._�m--�' - 'w i io- __ _ _ � 1 III�Ill1� I Y��I'll�j�l � � \�\� \ � \ \1 I1� / i ' --- --- _ _ r.+ +e�. so _— W . ,., .. ,. � - .._.r. __ .. � �._..� _ ---- � _-- — - ___ __________—""_'' Illlll� �q��ll��il'"I \ I \\\\\�\ \� `�, I % //�r-_ _ _ ___ - —__�.___ ---� — � _ -: i II��(I'�+�\� 11 II � \ � \� \ � / � /�`l I� i ' � �° ^� � YII'11'I'I��11�1�11`�' �i' ' � \ \\�\ \\\11`� � � f� ;,�I S � � � �'-� u�u��i��4�� i � , i I � ---_"`-----=`� �a�� i / � � ' � �� \ _......__— ��li��"� � � � �i � � I i i n,�� „��`i��i� '�1 , "i_ ;, ` ii �il a.i� n ��\\��" 1� � � � � �1� �i �i� " o � 1i, �;j d` g ��1�U1\��11I I 11� �\ 1 1 � ` I � M 1 I�� I �j�11\�fl�� 1 � �1 � � � :�� I � �tl� n� � �//�1//�II�� V 1� � h I I I �. I � ��„f;i1�� ,, ;i i i i � , `�' i; �"� � :r � 'r�� ' � � ;� �� '�� t � 1 V��1�� 1A l I ' � . {� �� t �n` 11 �� I��I � - T� c'j H; �\ �\\� � �� I 1 I� � � I .� \�� `1 �� ' 1 I� � � �� \;11 I I � �� p %�� I� ��\ .�z �\, �� 1 1 I� �� ;� �I i�� '�,� �� , , i i i i y :4 �i � ��`�� -�\�� j� � Z � �I \ � �I �� I I I P �� A��A� � j � � � � � _� � > ' ' ' —I �i - E i i i � t — �� i � ,� ii '>�� `� � i�`� i � � i� f�'�' � � � � � �� i �,.�� p �� O j � m : � i � � n �;�%' _ \ � . r ��. m � I Z �� '� � Z I I � �� ' � � � I � � ` �M � . .,�::�� N _l,C� � �11'�� , II '� . ^' r" p � p -- -------------_____ _ _ _ _.... N � � „ � . , � ` r � 'I� Z m O 0 O D �--�--_ ;; _. m m '�I --.....� O V+ m T m `� .��,� > 1 � `� tn 0 v m v �� J I / �'� � Z m � � � ' 2 2 �v � •---_ �v —� ---- � D D r^ m � �G . \z� D D D D �� — v v < ., �, � � v v :} -'r ` � � � � � �-__._ ,,. o � � r y n � � � �s z D � � n � Z Z �s y°b m z � W ` � � y —. -- - ' � C1 O . Z 0 n __� � 1 � ._ � W _.._ -- C , _ —. _- - - s _, .�,.,�,.��- Zy ' ' — -�� v „ °z m o Z __ _ ' ---�, 108TH AVENUE SE n � Z -�- - -- ,� __---._ _ � T `_.__�,,,r_-_._J _ J �....,�.�.,�_.�..._. � __ m Z m _ - . m � '� - _ ,C i^ Z m � � v D � z � DO o � m � � v N � O � �DESIGN? KCHA-29-03 NEW STEEP SLOPE AND EROSION HAZARD AREAS 10700 Meridian Avenue North-Suite 210 SeattIeWA98133 FEBRUARY 2014 VANTAGE POINTAPARTMENTS FIGURE 6 Off 206.838.9900 Fax 206.838.9901 RENTON�WQ1 Q X � 0 Z W a a � Q I APPENDIX A FIELD EXPLORATIONS GENERAL Subsurface conditions at the site were explored by completing five additional borings (B-5 through B-9)to depths ranging between 16.5 and 61 .5 feet BGS. The borings were completed on December 19, 2013 by Geologic Drilling, Inc. of Spokane,Washington, using a trailer rig and hollow-stem auger drilling techniques. A well was installed to a depth of 60.0 feet BGS in boring B-6. The exploration logs from the recent explorations are included in this appendix. The locations of the explorations were determined in the field by using hand-held GPS equipment. This information should be considered accurate to the degree implied by the methods used. A member of our geotechnical staff observed the explorations. We obtained representative samples of the various soil encountered in the explorations for geotechnical laboratory testing. Samples were obtained using an SPT sampler at 2.5- and 5-foot intervals. SOIL CLASSIFICATION The soil samples were classified in accordance with the "Exploration Key" (Table A-1) and "Soil Classification System" (Table A-2), which are included in this appendix. The exploration logs indicate the depths at which the soil or its characteristics change, although the change could be gradual. A horizontal line between soil rypes indicates an observed change. If the change was gradual the change is indicated using a dashed line. Classifications and sampling intervals are presented on the exploration logs included in this appendix. LABORATORY TESTING CLASSlFICATION The soil samples were classified in the laboratory to confirm field classifications. The laboratory classifications are presented on the exploration logs if those class f�cations differed from the field classifications GRAlN-S1ZE ANALYSlS We completed grain-size testing in order to determine the distribution of soil particle sizes. The testing was completed in general aaordance with ASTM D 422, ASTM C 136. ASTM C 1 1 7, and ASTM D 1 140. The results of the testing are presented in chis appendix. MOISTURE CONTENT We tested the moisture c�ntent m general accordance wi[h ASTM D 221 6. The moisture concent is a ratio of the weight of the water to soil in a test sample and is expressed as a percentage. The overall moisture contents range from 20 to 24 percent. The results of the testing are presented r this �ppend��x. .��.U�__�.1, � A 1 KCHA ly U3.U124� -: SYMBOL SAMPLING DESCRIPTION � Location of sample obtained in general accordance with ASTM D 1586 Standard Penetration Test with recovery � Location of sample obtained using thin-wall Shelby tube or Geoprobem sampler in general , accordance with ASTM D 1587 with recovery � Location of sample obtained using Dames & Moore sampler and 300-pound hammer or pushed , with recovery � Location of sample obtained using Dames & Moore and 140-pound hammer or pushed with recovery � Location of sample obtained using 3-inch-O.D. California split-spoon sampler and 140-pound hammer � Location of grab sample Graphic Log of Soil and Rock Types ��_•�' Observed contact between soil or Rock coring interval �:,�:�= � rock units (at depth indicated) ' �r � Water level during drilling Inferred contact between soil or rock units (at approximate depths indicated) � Water level taken on date shown .. . ' - - ,. �,. '-5 GEOTECHNICAL TESTING EXPLANATIONS ATT Atterberg Limits PP Pocket Penetrometer CBR California Bearing Ratio P200 Percent Passing U.S. Standard No. 200 CON Consolidation Sieve DD Dry Density RES Resilient Modulus DS Direct Shear SIEV Sieve Gradation HYD Hydrometer Gradation TOR Torvane MC Moisture Content UC Unconfined Compressive Strength MD Moisture-Density Relationship VS Vane Shear OC Organic Content kPa Kilopascal P Pushed Sample ENVIRONMENTAL TESTING EXPLANATIONS CA Sample Submitted for Chemical Analysis ND Not Detected P Pushed Sample NS No Visible Sheen PID Photoionization Detector Headspace SS Slight Sheen Analysis MS Moderate Sheen ppm Parts per Million HS Heavy Sheen �DESIGN? EXPLORATION KEY TABLE A-1 i o�oo nk�d�,,w��riorcn-wrce no SeaMe WA 98133 �� Olf 206.838.9900 Fau 206838.9901 I RELATIVE DENSITY-COARSE-GRAINED SOILS Relative Density Standard Penetration Dames&Moore Sampler Dames&Moore Sampler Resistance (140-pound hammer) (300-pound hammer) VeryLoose 0-4 0- 11 0-4 Loose 4- 10 1 1 - 26 4 - 10 Medium Dense 10- 30 26 - 74 10- 30 Dense 30- 50 74- 120 30-47 Very Dense More than 50 More than 120 More than 47 CONSISTENCY- FINE-GRAINED SOILS Consistency Standard Penetration Dames& Moore Sampler Dames&Moore Sampler Unconfined Compressive Resistance (140-pound hammer) (300-pound hammer) Strength (ts� Very Soft Less than 2 Less than 3 Less than 2 Less than 0.25 Soft 2 -4 3 -6 2 - 5 0.25 -0.50 Medium Stiff 4-8 6- 12 5 - 9 0.50- 1.0 Stiff 8- 15 12 -25 9- 19 1.0-2.0 Very Stiff 15 - 30 25 -65 19- 31 2.0-4.0 Hard More than 30 More than 65 More than 31 More than 4.0 PRIMARY SOIL DIVISIONS GROUP SYMBOL GROUP NAME CLEAN GRAVELS �y ar GP GRAVEL GRAVEL (< 5%fines) (more than 5096 of GRAVEL WITH FINES G1N-GM or GP-GM GRAVEL with silt coarse fraction �Z 5%and s 12%fines) GW-GC or GP-GC GRAVEL with clay COARSE-GRAINED retained on GRAVELS WITH FINES GM silty GRAVEL No.4 sieve) GC cla e GRAVEL SOILS (> 12%fines) y y GC-GM silry,clayey GRAVEL (more than 5096 CLEAN SANDS retained on SAND (<5%fines) SW or SP SAND No. 200 sieve) (50%or more of SANDS WITH FINES SW-SM or SP-SM SAND with silt coarse fraction �Z 5%and s 12%fines) SW-SC or SP-SC SAND with clay passing SANDS WITH FINES SM silty SAND No.4 sieve) �� 2%fines) SC clayey SAND SC-SM silry,clayey SAND ML SILT FINE-GRAINED CL CLAY SOILS Liquid limit less than 50 CL-ML silty CLAY (50%or more SILT AND CLAY OL ORGANIC SILT or ORGANIC CLAY passing MH SILT No. 200 sieve) Liquid limit 50 or CH CLAY greater OH ORGANIC SILT or ORGANIC CLAY HIGHLY ORGANIC SOILS PT PEAT MOISTURE ADDITIONAL CONSTITUENTS CLASSIFICATION Secondary granular components or other materials Term Field Test such as or anics,man-made debris,etc. Silt and Clay In: Sand and Gravel In: very low moisture, Percent Fine�rained Coarse- Percent Fine-Grained Coarse- dry dry to touch Soils Grained Soils Soils Grained Soils moist damp,without < 5 trace trace < 5 trace trace visible moisture 5 - 12 minor with 5 - 15 minor minor visible free water, > 12 some silry/clayey 1 5 - 30 with with wet usually saturated > 30 sandy/gravelly Indicate% C�DESIGN? SOIL CLASSIFICATION SYSTEM TABLE A-2 :0700 Mer�dian Avenue Nor[h-SuiOe 210 5'attk WA 98133 ' 01f 206.838.9900 Fax 206.838.9901 . Z o �= u w ♦ BLOW COUNT INSTALLATION AND DEPTH u Q� Z a � MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION >W � g FEET � W� � N � RQD96 �CORE REC% u o so iao Medium dense, light brown SAND (SP), trace silt; dry to moist, fine. , 5 � -6 Thin layer of gravel at top of sample. 10 dense; interbedded with dense light r �o brown with interbedded orange layered, � � silry SAND (SM); moist,fine at 10.0 feet � 5 15 - - - - — n 23 siev L � Stiff, light brown with orange layered 1�0 � SILT with sand (ML); moist, sand is fine. � �5 20 hard at 20.0 feet �� ; sandy at 20.5 feet r : 25 very stiff at 25.0 feet �� gray at 25.5 feet � Y 30 v � =� � m � Exploration completed at a depth of 31.5 Surface elevation was not measured at the time of Q31.5 fe2L : exploration. 0 � z � a 35 r O u z u � , o o : u d Qu', 40 p 50 100 m ni o DRILLED BY:Geobgic Drilling,Inc. LOGGED BY:TAP COMPLEfED:1?/19/13 c, N � BORING METHOD:holbw-stem auger(see report text) BORING BIT DIAMETER:frinc� Y `� u KCHA-29-03 BORING B-5 z �DESIGN� � 10700 Mendiar Avenue North-Suite 210 FIGU RE A-1 m Seattle WA 98133 FEBRUARY 2014 VANTAGE POINT APARTMENTS . Off 206.838.9900 Fax 206.838.9901 RENTON,W1�1 O = U w �BLOW COUNT I z � INSTALLATION AND DEPTH u d •MOISTURE CONTENT% = MATERIAL DESCRIPTION W � g COMMENTS FEET � � � N � RQD% �CORE REC% u o so too Dense, light brown SAND (SP),trace silt; ! dry to moist fine, interbedded with Fi�sn-m°"�` , monument with 2 dense light brown, silty SAND (SM); Clry feet of concrete to moist, fine. ba`kf�u I Native backfill 5 r�' =� � 2-inch,Schedule 40 i �j PVC well casing I iil 10 � 45 �; � Dense, light brown, silty SAND (SM); dry 12�5 ia : � to moist, fine. � � � 15 very dense; moist at 1 5.0 feet s�Ev � • �4 � Very stiff, light brown SILT with sand "�0 (ML); moist, sand is fine. 18 � Cuttings are wet at - 18A feet. 2° gray at 20.0 feet �� Hard, gray, sandy SILT with gravel (ML); z3.° moist to wet, sand is fine to medium, 25 gravel is fine to coarse. � 3� � : Cobble at 24.5 feet. � � '', Bentanite chips � i I r 29.5 Dense ra sil SAND SM minor Y 30 � 9 Y, tY ( ), � gravel; Wet, fine to medium gravel is �8 Cuttingsareverywet � ' � at 30.0 feet. c fine to coarse. � N W � � Hard, gray SILT with sand (ML), minor 33.0 � � gravel; moist, sand is fine to medium, � 35 gravel is fine. L sa � interbed of hard CLAY (CH); dry at 35.5 �� Z feet u o � V a � . �. '� �. �. °V�' 40 I 0 50 100 � m T Q DRILLED BY:Geologic Driling,Inc. LOGGED BY:TAP COMPLETED:12/19/13 m N � BORING METHOD:hollow-stem auger(see report teut) BORING BIT DIAMETER:8-inch Y z �" BORING B-6 D ES I G N? KCHA-29-03 � 10700 Mendian Avenue North-Sui[e 210 VANTAGE POINT APARTMENTS FIGURE A-2 m Seattk WA 98133 FEBRUARY 2014 Off 206.838.9900 FaX 206.838.9901 RENTON,WA O = U w �BLOW COUNT z � INSTALLATION AND DEPTH � o- •MOISTURE CONTENT% = MATERIAL DESCRIPTION W � g COMMENTS FEET � 0 � Q '� RQD% 0 CORE REC% v'i 4 u o so ioo (continued from previous page) ' 4z; ' � , � � a c I � v , Driller � Comment o- 45 Dense, ra -brown SAND (SP), trace silt; 45'0 n 41 ' sand'feel fram �1 g Y �� as.o co aa.o wet,fine to medium. �� feet. � 10 feet of water in ' hole at 45A feet. Dense, gray SAND with silt (SP-SM), ae.o trace silt; moist to wet,fine to medium, gravel is fine. ioizor�ite.pa�k SO n = sand �� '� 2-inch,slotted - Schedule 40 PVC, — 0.010-inch slot wldth s5 very dense at 55.0 feet � �o : � 60 � � 5 � Exploration completed at a depth of 61 S Surtace elevation was not measured at the 61.5 feet. time of exploration. 65 Y 7O v � m � N li! � Q � � . Z � d 75 � 0 u z u � 0 0 V a °i 80 0 50 100 m o DRILLED BY:Geokigic Driling,Inc. LOGGED BY:TAP COMPLETED:12/19/13 o+ N � BORING MEfHOD:holbw-stemauger(seereporltext) BORING BIT DIAMETER:B-inch Y � u KCHA-29-03 BORING B-6 z �DESIGN? (continued) � 10700 Mendiar Avenue North-Suite 210 FIGU RE A-2 m Seattle WA 98133 FEBRUARY 2014 VANTAGE POINT APARTMENTS Off 206.838.9900 Fax 206.838.99�1 RENTON,W/� o = u w � BLOW COUNT INSTALLATION AND DEPTH u Q� Z a •MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION >w � g FEET � W� � N �� RQD% �COREREC% U 0 50 100 Medium dense, brown SAND (SP), trace silt; dry to moist, fine. 5 n -� � � Very stiff, brown SILT with sand (ML); 8•0 moist, sand is fine. io � 25 �: dense; interbedded with dense, brown, s�ev �, • �� silty SAND (SM); moist, fine at 12.5 feet ; �S Medium dense, gray SAND with silt (SP- �as i SM); moist, fine. � �' i Hard, gray, sandy SILT(ML); moist, sand ��•0 is fine. � �' 20 ; very stiff at 20.0 feet r �a : � ; 25 29 L Very dense, gray, silty SAND with gravel 29•0 Y30 Driller Comment: gravel at � (SM); moist,fine to medium, JfdVel IS 80 29A feet. � fine to coarse. � � � � Exploration completed at a depth of 31•5 Surtace elevation was not r3�.5 feeL. measured at the time of a exploratlon. 0 H Z i � i d 35 � 0 u z u � 0 0 w u s ,�,� 40 o so too � m o DRILLED BV:Geobgic Driling,Inc. LOGGED BY:TAP COMPLETED:1?J�9N3 o+ N � BORING METHOD:holow-stemauger(seereporttext) BORING BIT DIAMETER:6-inch Y � v KCHA-29-03 BORING B-7 z �DESIGN� � 10700 Meridian Avenue North-Suite Z10 I o VANTAGE POINT APARTMENTS x s.�,,<<iFwa9s�s3 FEBRUARY 2014 FIGURE A-3 . .. — .. :, , o = u w � BLOW COUNT INSTALLATION AND DEPTH � � � a • MOISTURECONTENT% COMMENTS = MATERIAL DESCRIPTION g FEET � W� � N � RQD96 �CORE REC% u o so ioo Stiff, orange-brown, sandy SILT(ML), trace gravel; moist, sand is fine to medium, gravel is fine. � o � 5 — 14 � — i Dense, gray-brown SAND (SP),trace silt; 8•� I DrI1lerComment: sandat dry to moist, fine to medium. s.o reec. t o � ---- 38 � 15 -- — very dense at 15.0 feet � ss: EXP�O�di1011 COfTlp�eieC� dL d C�2pt�'1 Of 16.5 Surface elevatlan was not �6.5 feet. explorat a�t the tlme of 20 - -- 25 Y 30 v � m � N W F Q � F Z C a 35 —- � c u z u � O O w u d a 40 0 SO 100 m a DRILLED BY:Geologic Driing,Inc. LOGGED BV:TAP COMPLETED:12/19J13 m N vBORING METHOD:hdbw-stemauger(seeiepattext) BORING BIT DIAMETER:fi-inch Y z �DESIGNZ KCHA-29-03 BORING B-8 � �o�oo Me��dian Avenue North-Suite 210 VANTAGE POINT APARTMENTS FIGURE A-4 m Off 206.838.9900WF x8206.638.9901 FEBRUARY 2014 RENTON,WA Z o �= u w ♦BLOW COUNT INSTALLATION AND DEPTH v Q� Z d •MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION >W f- g FEET � W 0 � N _j] RQD% �CORE REC% u o so tao Very dense, gray-brown SAND (SP), trace silt; dry to moist, fine to medium. 5 10 interbedded with very dense, gray- brown, silty SAND (SM); dry to moist, fine at 10.0 feet �5 dense at 1 5.0 feet : Exploration completed at a depth of 16.5 Surface elevation was not �6.5 feet. measured at the time of exploratlon. 20 , 25 Y 30 — : v � � � N W � Q Q � Z � 1 35 ' 0 u z u � w 0 0 u a � 40 0 50 100 m a DRILLED BY:Geologic Driling,Inc. LOGGED BY:TAP COMPLETED:12N9/13 rn N � BORING METHOD:holbw-stem auger(see report taxt) BORING BIT DIAMETER:6-inch Y ° �DESIGN? KCHA-29-03 BORING B-9 � 10700MeridianAvenueNorth-Suite210 FIGURE A-5 m Seattle WA 96133 FEBRUARY 2014 VANTAGE POINT APARTMENTS Ofl 206.838.9900 Fax 206.838.9901 RENTON,WA GRAIN SIZE NO P200 KCHA-29-03-BS 9.GPJ GEODESIGN.GDT PRINT DATE:2/12/14:KT U.S. STANDARD SIEVE NUMBERS 3" 1 1/2" 3/4" 3/8" 4 10 ZO 40 60 100 200 100 I ., 90 ----- ---- - _- - �. �� • 80 ---- --- _ - H , = 70 ----- -- - -i --- - -- ---- -- ----- u w � 60 - --- - — -- -- . m ac W ' _.._______. Z __. .__- __ ._ . LL � w 40 --- - - - - V oC d 30 - _ ---- -. .. - - - - 20 _- - --- 10 -- - -- -------- i 0 1,000 100 10 1 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS __ GRAVEL SAND FINES BOULDERS COBBLES � - � COARSE FINE COARSE I MEDIUM FINE SILT I CLAY I �i EXPLORATION AMPLE DEPTH MOISTURE CONTENT r � �' GRAVEL SAND SILT CLAY _ - D50 D30 D10 D5 �pERCEN� (PERCEN� (PERCENn (PERCENn NUMBER �_(FEET) (PERCENn D60 ' j { • B-5 15.0 24 ' 0 17 83 � I B-6 1 5.0 - 20 0 ..- 14 86 • I B-7 12.5 24 _ 0 . 6 94 -- t _ - - -- � � _ I �DESIGN? KCHA-29-03 GRAIN-SIZE TEST RESULTS 10700M<ridlanAvenueNorth-Suhe210 VANTAGE POINTAPARTMENTS SeattleWA98133 FEBRUARY 2014 RENTON,WA FIGURE A-6 Olf 10fi.P38.9900 Fax 206.838.9901 SAMPLE INFORMATION SIEVE ATTERBERG LIMITS MOISTURE DRY SAMPLE CONTENT DENSITY LIQUID PLASTIC PIASTICITY EXPLORATION DEPTH ELEVATION GRAVEL SAND PZ�4 LIMIT LIMIT INDIX NUMBER (FEE� (PERCENI� (PCF) (pERCENn (PERCENn (PERCENI j (FEE� (PERCEN� (PERCENI� (PERCENI� B-5 15.0 24 ; 0 17 83 B-6 15.0 20 0 14 86 B-7 12.5 24 0 6 94 � Y v � N \ � Q � r z z a � 0 V Z V � W � 0 W V d V oi � m M 0 o� N Q _ l.l Y a �DESIGN? KCHA-29-03 SUMMARY OF LABORATORY DATA � � N �o�ooMe�idiann�enuet+orch-suicez�o VANTAGE POINTAPARTMENTS FIGURE A-7 m Seattle WA 98133 FEBRUARY 2014 RENTON,WA g OH 2O6.838.9900 Fau 206.838.9901 m x � z W a a Q o = u w �BLOW COUNT INSTALLATION AND DEPTH � � � a •MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION FEET � 0 � � � RQD% �CORE REC% u o sa ioo Soft,dark brown SILT with organics `,(roots); moist (topsoiq. os Stiff, brown SILT with concrete debris, cobbles, and boulders (ML),trace sand; moist, low plasticity, sand is fine - FILL. �, i� light brown, sandy at 3.75 feet Felt cobbles or rocks;hard 5 ' �Z drilling at 4.0 feet. Debris encountered at 4.0 feet. Moving approximately Dense, light brown with orange mottled �•0 3 feet south. SAND (SP); dry,fine. � �3 without mottles at 7.5 feet �� very dense at 10.0 feet ' zssiiorvs• 15 � �� trace silt at 16.0 feet Very dense, light brown SAND with silt 18�0 (SP-SM); dry, fine. 20 � sz: with orange mottles at 20.5 feet Very stiff, gray SILT(ML),trace sand; 2z•5 dry, medium to high dry strength, low plasticity, sand is fine. zs � �3. Y �"' Very dense, gray, silty SAND (SM); dry, 28•0 ' N ' fine. _ m j_ W 30 o + ' �08 Outside of sampler was wet at 30.0 feet. Z � Perched water at � approximately 30.0 feet. a o Hard, gray SILT(ML), trace sand; dry, 33.0 � ' j medium to high dry strength, low � 35 I 'I plasticity, sand is fine. `� 3 7 - W � u �� a u � o : ,_ � v� � N 40 0 50 100 ' o Q DRILLED BV:HottServices,Iro. LOGGED BY:TAP COMPLETED:02/25/13 a N vBORING METHOD:hdbw-stem auger(see report te#) BORING BIT DIAM EfER:8-inch Y o �DESIGN? KCHA-29-01-02 BORING B-1 z � 10700 Meridian Avenue North-Suite 210 o VANTAGE GLEN - MULTI-FAMILY RENTAL PROJECT m SeattIeWA98133 MARCH 2O13 FIGURE A-1 ��,. Off 206.838.9900 Fax 206.838.9901 RENTON,WA o = u w �BLOW COUNT INSTALLATION AND DEPTH v � Z � •MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION >W � FEET � W 0 � � � RQD% �CORE REC% u o so too (continued from previous page) � s� �. Exploration completed at a depth of 41.5 I Surface elevation was not measured at the time of 41.5 feei. exploration. 45 50 SS 60 65 r Y M � N \ M � �O Q � ~ Z O�. . �. �. �. 1 r 0 u z � 75 W 0 � W V d V �i i H �i I m $� N 0 50 100 0 � DRILLED BY:Fbtt Services,Inc. LOGGED BY:TAP COMPLETED:D2125/13 rn N uBORING METHOD:hollow-stemauger(see reportteu[) BORING 81T DIAMETER:8-inch Y V � u KCHA-29-�1-02 BORING B-1 � • DESIGN? (continued) Z � 10700 Meridian Avenue North-Suite 210 m Seattle WA 98133 MARCH 2O13 VANTAGE GLEN- MULTI-FAMILY RENTAL PROJECT Off 206.838.9900 Fax 206.836.9901 RENTON,WA FIGURE A-1 Z o = u w �BLOW COUNT INSTALLATION AND �, DEPTH v Q� � d •MOISTURE CONTENT% COMMENTS �I = MATERIAL DESCRIPTION g FEET � � � � ;J�' RQD% �CORE REC% t,7 0 50 100 ' Soft, brown SILT with sand (ML),trace gravel; moist, low dry strength, low plasticity, sand is fine, gravel is fine - ' FILL. � 3 5 � = Very stiff, light brown, sandy SILT(ML); 7-0 dry, low dry strength, low plasticity, � �' sand is fine - FILL. �o � gray,with sand; medium dry strength at ' 3a 10.0 feet � Very stiff, gray, SILT(ML), trace sand; '3.0 moist, sand is fine, medium dry : �s strength, low plasticiry. _ � 27 � ; 20 hard at 20.0 feet sz: C - z5 becomes with sand, trace gravel; high � =o dry strength, sand is fine to medium, gravel is fine at 25.0 feet � Y "' Very dense, brown with orange mottled 28�0 � � SAND with silt (SP-SM), minor gravel; W 3o dry, fine to medium,gravel is fine. o ' 2&91-tOq/3• � z a i o Very dense, brown SAND with gravel 33.0 � Z (SP); dry,fine to medium, gravel is fine. i : � 35 I o � 2&s0�s ' u d I u � : i a H � v , O0 40 0 50 100 N O Q DRILLED BY:Fblf Services,Inc. LOGGED BY:TAP COMPLETED:02f25113 m N � BORING METHOD:holbw-stem augx(sea ieport text) BORING BIT DIAMETER:8-inch Y � �DESIGN? KCHA-29-U1-02 BORING B-2 � 10700 Mendian Avenue North-Sui[e 210 m Seattle WA 98133 MARCH 2O13 VANTAGE GLEN-MULTI-FAMILY RENTAL PROJECT Off 206.838.9900 Fax 206.638.9901 RENTON,WA FIGURE A-2 o = u �., �BLOW COUNT INSTALLATION AND DEPTH u Q� Z a •MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION >W � � FEET aQ W 0 W Q � RQD% ,�CORE REC% oC w � � u o so ioo 4 interbeds of trace silt at 40.0 feet sa-3asa+3• Exploration completed at a depth of 41'3 Surface elevatlon was not 41.2 5 fEeL. measured at the time of exploratlon. 45 � 50 55 60 65 Y m � N \ W 7O � a : 0 � z � a � 0 u z � � 75 0 0 u a � u : � � v � m 80 0 50 100 � o o DRILLED BY:Fblt Servioes.Inc. LOGGED BV:TAP COMPLETED:02125/13 o+ N � BORING METHOD:holow-s0em auger(see report text) BORING BIT DIAMETER:8-inch I � u KCHA-29-01-02 BORING B-2 z �D ES I G N? (continued) O 10700 Mendmn Avewe NORh-Suite 210 VANTAGE GLEN-MULTI-FAMILY RENTAL PROJECT FIGURE A-2 1 m Seattle WA 98133 MARCH 2O13 Off 206.838.9900 Fax 206.838.9901 RENTON,{NA1 o �= u w �BLOW COUNT INSTALLATION AND I DEPTH � a� Z a •MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION >W � � FEET a w 0 W Q [�j RQD% �CORE REC% � w H �+ u o sa ioo Stiff, brown SILT(ML), trace sand; moist, low dry strength, low plasticity, sand is fine - FILL. G 9 � Loose, light brown, silry SAND with 3.s ravel SM d fine to medium ravel 4.5 Gray felt at approximately 5 ',9 � �� rY� �9 a.o teet. ',is fine. ' i��d,oars• Very dense, brown with orange mottled SAND with gravel (SP),trace silt; dry, fine to medium,gravel is fine to coarse. �6 �� without mottles at 10.0 feet ' i�,�,ov�a• �s brown at 1 5.0 feet � asu�s• Very dense, brown, silty SAND with 18•0 gravel (SM); dry,fine to medium,gravel Zo is fine to coarse. r 2s-sEus s-5 l� SFT left In boring avernight. ; Large,smooth obstruction at approximately 21.0 feet. Drllling refusal met at 21.0 I ' i feet;hole terminated. i Very dense, br�wn SAND with gravel 23•� geeW hydraulic hose at 21A (SW); C�ry, fine to coarse, 9�dVeI IS flfle : Coarse gravel ac , i0 COdfSe. approximately 22.0 feet 25 �' Moved boring approximately 42-SfUS 10 feet northwest of original : boring down to 25.0 feet. Y m � N � M W 30 r Q ` : 47-SplS• 0 � z oe d 0 u z u i5 o ' 3'f-10p/5' w u � a u �� a � v � 00 4� 0 50 loo N O 4 DRILLED BY:HoR Servicas,Inc. LOGGED BV:TAP COMPLEfED:02126113 rn N � BORING METHOD:Falbw-slem auger(see report te#) BORING BIT DIAMEfER:&inch Y ° �DESIG N? KCHA-29-01-02 BORING B-3 Z � 1C7GCMendianAvenueNorth-Suite210 FIGURE A-3 m Seattle WA 98733 MARCH 201 3 VANTAGE GLEN - MULTI-FAMILY RENTAL PROJECT or� zoE s3a y�oo Fax zo6 s3s.990 RENTO'J,WA Z I o —= u w .e�ow couNr INSTALLATION AND ' DEPTH v � � a •MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION g FEET � W� � N � RQD% 0 COREREC% 4 u o so ioo i (continued from previous page) 40.5 Surface elevation was not � EXplOfdil011 COfilpleiECl dL d f�2pth Of ineasured at the time of I 40.5 f2eL exploration. 45 — � 50 55 60 , 65 � Y M � N \ m i� 70 H Q 0 F z oe a � 0 u z � 75 0 0 W U d u � d r �� 80 � ` m 0 50 100 N O � DRILLED BY:Hofl Services,Inc. LOGGED BY:TAP COMPLETED:02/26/13 rn N � 80RING METHOD:hdbw-stem auger(see reportte�d) BORINL BIT DIAMETER:&inch Y � u KCHA-29-01-02 BORING B-3 z �DESIGN? (continued) � 10700 Mendian Avenue North-Suih 210 FIGU RE A-3 m Seattle WA 98133 MARCH 2O13 VANTAGE GLEN - MULTI-FAMILY RENTAL PROJECT Off 206.838.99D0 Fax 206.838.9901 RENTON,W{� Z o —= u w �BLOW COUNT INSTALLATION AND DEPTH u � � a •MOISTURE CONTENT% COMMENTS = MATERIAL DESCRIPTION � FEET � � � N __I] RQD% �CORE REC% u o so ioo Stiff, brown SILT with sand and gravel (ML); moist, low dry strength, low plasticity, sand is fine, gravel is fine - FILL. 9 1 _ _ [�� ' Very dense, light brown SAND (SP); dry, 4'� Hard grinding at 5 fllle LO �YIedlUfll. ' approximately 4.0 feet. lll gray; moist, interbeds of very dense, gray, silty SAND (SM); moist, fine at 7A r �� feet L io ' 158 Hard, gray SILTwith sand (ML); dry, high ��•0 dry strength, low plasticity, sand is fine. Very dense, gray SAND (SP), minor �3.s gravel,trace silt; dry,fine to medium, � �5 gravel is fine. � � — 84 � � �__ _ _ : Very dense, gray, silty SAND (SM); dry, 18•0 � fine, interbeds of very dense, gray Za SAND (SP); dry,fine. r �2 l Hard, gray SILT with sand (ML); dry, high 23.0 dry strength, low plasticiry, sand is fine. zs � i8 I � Y m � N � fM W 3� I __ Q � �6 Zminor gravel at 31.0 feet a a H O u i 0 35 interbeds of very dense, gray SAND (SP), :z � minor gravel; dry, fine to medium, � d gravel is fine at 35.0 feet u � Very dense, gray SAND (SP); dry,flfle. 38'0 Hard grinding at 38.0 feet. e � 00 4� 0 SO 100 N O Q DRILLED BY:Hott Services,lnc. LOGGED BY:TAP COMPLETED:02/26113 m N � BORING MEfHOD:holav-s0emaugx(seereporttext) BORING BITDIAMETER:B-inch Y -- ° �DESIGN? KCHA-29-01-02 BORING B-4 Z o io�cc„e�� F.��e Nortn-s�a�no VANTAGE GLEN- MULTI-FAMILY RENTAL PROJECT FIGURE A-4 m Seattle WA 98133 MARCH 2O13 Off 206.838.9900 Fax 206.836.9901 RENTON�WA o = u w �BLOW COUNT INSTALLATION AND DEPTH � � Z a •MOISTURE CONTENT% COMMENTS FEET a MATERIAL DESCRIPTION W o � g � w Q LII_ RQD96 ',�CORE REC% w H �+ 4 U 0 50 100 (continued from previous page) 3,-,oas• EXplOfdtlOfl COfT1p�2iEC� dL d depth Of 41A Surface elevation was not measured at the time of 41.0 fe2L. explontion. 45 50 55 60 65 Y m � N \ W JU -- � a � z a F � I u z � 75 - , 0 0 w u I u I �, I d F a i m a� 0 50 100 � 0 o DRILLED BY:FbM Services,lnc. LOGGED BV:TAP COMPLETED:02126/13 o+ N � BORING METHOD:holbw-stem auper(see raportte�d) BORING BIT DIAMEfER:B-inch Y " BORING B-4 � u KCHA-29-O 1-02 u � ESIG N? (continued) z � 107G0 Meridlan Avenue North-Suite 210 FIGURE A-4 m Seattle WA 98133 MARCH 2O13 VANTAGE GLEN- MULTI-FAMILY RENTAL PROJECT Off 206.83H.9900 Fax 206.638.9901 RENTON,WA o = u w Z � •MOISTURE DEPTH = MATERIAL DESCRIPTION >W � g CONTENT COMMENTS FEET a �� W a �� w H � u TP"� o so ,00 o.o -- TOPSOIL (6 inches). Soft, brown SILT with sand (ML); moist, o.s � ��,low dry strength, low plasticity, sand is ; ��0 ',fine - FILL. ; 6-inch orange streak at 2.0 feet. z'S Medium dense, light brown SAND (SP), � trace gravel; moist, fine to medium, PP PP= Z•35 tsf grdvel is fine. Nuclear density: 1 18.1 pcf, dense at 3.5 feet , : moisture 1 8.6 percent at 4.0 feet. SA Very dense, light brown, silry SAND 6.0 (SM); dry,fine. 7.5 ` l0A Ex loration com leted at a de th of �o-S PP � PP=>4.5 tsf P P p No groundwater seepage observed 10.5 feet. to the depth explored. No caving observed to the depth i 2,5 explored. Surface elevation was not measured at the time of exploration. TP-2 o so ,00 o.o o so ioo -- TOPSOIL(6 inches). Soft, brown SILT with sand and gravel os '� (ML); moist, low dry strength, low rr PP= 1.0 tsf I plasticity, sand is fine, gravel is fine to Y 2•5 coarse - FILL. � 3.3 Nuclear density: 1 12.6 pcf, � Dense, light brown with orange mottled PP 0 moisture l 3.5 percent at 3.5 feet. m SAND (SP), trace silt; dry, sand is fine. PP= 2.65 tsf w Q s.o 0 Z horizontal orange streaks at 5.5 feet a very dense,without horizontal streaks at 6.0 feet � o �s u z u � w 0 0 W � l0A � : No groundwater seepage observed to the depth explored. No caving observed to the depth � explored. �� i2.5 Exploration completed at a depth of 12�0 � m 12.0 feet. Surface elevation was not o measured at the time of o exploration. �, N Q Y 0 5� ��Q � IXCAVATED BY:CoMinenWl Din Construc6on LOGGED BY:TAP COMPLETED:02/27/13 a a � w a EXCAVATION METHOD:trackhoe(see report te�d) � u KCHA-29-01-02 TEST PIT a �DESIGN� � 10700 Meridian Avenue North-Suite 210 VANTAGE GLEN- MULTI-FAMILY RENTAL PROJECT � F Seattle WA 98133 MARCH 2O13 FIGURE A-5 Off 206.838.9900 Fax 206.838.9901 RENTON,w{� v Z � �' Z � •MOISTURE DEPTH = MATERIAL DESCRIPTION >� � g CONTENT COMMENTS FEET d � W Q �o�� °�u ~ � I TP-3 o so ,00 �'� - TOPSOIL(6 inches). II Stiff, brown SILT with sand and os i �, � : cobbles (ML), minor gravel; moist, low Nuclear density: 123.7 pcf, , dry strength, low plasticity, sand is PP � moisture 18.2 percent at 1.75 feet. ' z•5 fine, gravel is fine to coarse - FILL. PP=2.5 tsf s.o Loose, gray, silty SAND with gravel and s.o debris (SM); wet,fine to medium, Moderate to severe caving gravel is fine to coarse, debris includes � observed at 6.0 feec. logs, copper pipe, and concrete brick- 7.5 � FILL. t 1 pA Very dense, gray, silty SAND (SM); dry, '�•0 vv � PP=>4.5 tsf `fine. >>.5 No groundwater seepage observed I to the depth explored. iz.s Exploration completed at a depth of ' 1 1.5 feet. Surface elevation was not ', measured at the time of exploration. TP-4 o so ,00 o so ioo �'� -- TOPSOIL (6 inches). os Soft to medium stiff, brown SILT(ML), minor sand and gravel; moist, low dry Nuclear densiry: 123.2 pcf, strength, low plasticity, sand is fine to PP � moisture 16.5 percent at 2.0 feet. Y Z•5 medium - FILL. PP= 1.6 tsf :� � �, c �, ¢ 5.o Moderate caving observed at 5.0 o feet. � Z a Loose to medium dense, gray, silty b.o SAND to SAND with silt (SM/SP-SM), o �.s minor gravel and debris (concrete, �`-: � Z wood, and pipe); wet - FILL. u w 0 W " 10.o No groundwater seepage observed " to the depth explored. 0 : � Exploration completed at a depth of 1�5 Surface elevation was not �� i 2.5 1 1.5 feet. measured at the time of m exploration. N I O I o IIN Q I _ Y � $0 ��Q � EXCAVATED BY:ContineMalDirtConshnufion LOGGED BY:TAP COMPLETED:02/27/13 ¢ a � w a EXCAVATION METHOD:tracldae(see report texl) N ° u KCHA-29-01-02 TEST PIT a �DESIGNz v~i 10700 Mendian Avenue North-Suite 210 VANTAGE GLEN - MULTI-FAMILY RENTAL PROJECT � Seattle WA 98133 MARCH 2O13 FIGURE A-6 Oif 206.838.9900 Fax 206.838.9901 RENTON�W/� o � u ,,,,, Z � •MOISTURE DEPTH = MATERIAL DESCRIPTION >w F- g CONTENT COMMENTS FEET a J o W Q �,�o� � w H � u TP-5 o.o o so ,00 -- TOPSOIL(6 inches). Medium stiff, brown SILT with gravel os (ML), minor sand; moist, low dry strength, low plasticity, sand is fine to PP � pp- 2.i csf z•5 medium - FILL. Nuclear density: 122.9 pcf, s.o Dense, light brown with orange mottled 4•5 PP � moisture 20.7 percent at 4.5 feet. SAND with silt (SP-SM); moist,fine to PP= 3.5 tsf medium. Very dense, brown SAND with gravel 6•5 No groundwater seepage observed 7.5 (SW); moist, fine to coarse, � to the depth explored. approximately 40%fine to coarse ex lored9�bserved to the depth g rave I. a.3 P Exploration completed at a depth of Surface elevation was not 8.25 feet. measured at the time of 10.o exploration. 12S TP-6 o so ,00 o.o o so ioo - TOPSOIL(6 inches). Medium stiff, brown SILT with sand °'S PP PP=o.3 tsf and cobbles (ML), minor gravel; moist, low dry strength, low plasticity, sand is Y 2•5 fine to medium,gravel is fine - FILL. � PP � PP= 1.0 tsf O1 Nuclear densiry: 1 18.5 pcf, m moisture 19.8 percent at 4.0 feet. w `0 5'0 Hard, gray, sandy SILT(ML); dry, high 5•0 Z dry strength, medium plasticiry, sand is d fine. rP � PP=>4.5 tsf Di�cult to continue excavating. � 7'S ��s No roundwater see a e Expl�ration completed at a depth of 7.5 9 p g observed u feet. to the depth explored. W No caving observed to the depth a explored. W � 10.0 � t = . Surface elevation was not j : measured at the time of exploration. a � � ' 12S m N O O Oi N Q _ Y � 5� �� u IXCAVATED BY:Continenfal Dirt ConsVucfion LOGGED BY:TAP COMPLETED:02l27/13 a a � w a E?(CAVATION METHOD:tracktae(see repoA te#) N � �DESIGN? KCHA-29-01-02 TEST PIT � �o�oo r,�e��dian Avenue North-Suite 210 VANTAGE GLEN- MULTI-FAMILY RENTAL PROJECT F Seattle WA 98133 MARCH 2O13 FIGURE A-7 Off 206.838.9900 Fax 206.836.9901 RENTON,W/� u � Z � •MOISTURE DEPTH = MATERIAL DESCRIPTION � � g CONTENT COMMENTS FEET � o � Q �o�p� � u TP-7 o.o o so ,00 TOPSOIL (6 inches). PP PP=4.5 tsf Stiff to very stiff, brown SILT with — os sand, gravel,and cobbles (ML), minor debris; moist, low dry strength, low 2.5 plasticiry, sand is fine to medium, grdvel is fine to Coarse - FILL. PP u Minor caving observed at 3.0 feet. PP= 2.0 tsf 5�0 Very stiff to hard, gray, sandy SILT(ML); s.o dry, low dry strength, low plasticity, sand is fine. 7.5 PP � : PP=>4.5 tsf Laminated pieces of light brown Very dense, light brown SAND with silt, 8•0 � with orange streaked,fine,silty gravel, and cobbles (SP-SM), moist, fine sand from 8.0 to 9.0 feet. `.to medium, gravel is fine to coarse. 9'0 No groundwater seepage observed t o.o Exploration completed at a depth of 9.0 to the depth explored. feet. Surface elevation was not measured at the time of exploration. 12.5 TP-8 o so ,00 o.o o so ioo -- TOPSOIL(6 inches). Stiff, brown SILT with sand, gravel, and os cobbles (ML); moist, low dry strength, rr PP= 2.2 tsf low plasticity, sand is fine to medium, Y 2•S gravel is fine to coarse - FILL. � � PP � �� , ��. ��. PP= 1.4 tsf i:i ' Q 5.0 0 � PP PP= 3.5 tsf z c a 0 7.5 i Very dense, gray, silty SAND (SM); dry, 7�0 . � fine. . � `,orange layer at 8.0 feet 8�0 No groundwater seepage observed w to the depth explored. o Hard, light brown with orange mottled ° SILT(MH), trace cla and sand; d No caving observed to the depth u Y rY� explored. 6 io.o � medium to high dry strength, medium � �o.o "• to high plasticiry, sand is fine, ; Surface elevation was not ^� �laminated layers. measured at the time of � Exploration completed at a depth of exploracion. `' �z.5 10.0 feet. m N ' O O a : N Q _ � � 5� �� Y Q EXCAVATED BY:CondneMal DirtCorwtruction LOGGED BV:TAP COMPLETED:02/27113 a � w a EXCAVATION METHOD:tracichoe(see repoA text) rv ° u KCHA-29-01-02 TEST PIT a �DESIGN= � 10700 Meridian Avenue North-Suite 210 VANTAGE GLEN - MULTI-FAMILY RENTAL PROJECT H Seattk WA98133 MARCH 2O13 FIGURE A-8 Off 206.838.9900 Fax 206.638.9901 RENTON,W/� Z o �= u w Z J •MOISTURE DEPTH = MATERIAL DESCRIPTION >W � � CONTENT COMMENTS FEET d w� W Q �,�o� � H � U TP'9 0 50 ,00 o.o -- TOPSOIL(6 inches). Stiff to very stiff, brown, gravelly SILT °•S PP PP= 3.5 tsf with sand (ML); moist, low dry strength, low plasticity,gravel is fine 2.5 to coarse, sand is fine to medium - FILL. PP � PP=4.0 tsf Nuclear density: 123.6 pcf, Hard, dark brown, sandy SILT with 4•0 moisture 18.5 percent at 3.5 feet. s.o gravel (ML); dry, high dry strength, low plasticity, sand is fine to medium, � gravel is fine to coarse, intermittent layers of clean gray fine to medium sand. : 7.5 Hard, gray, sandy SILT with cobbles and 9•0 No groundwater seepage observed io.o boulders (ML), minor gravel; dry, high to the depth explored. dry strength, low plasticity, sand is fine, No caving observed to the depth gravel is fine. �� o explored. Exploration completed at a depth of Surface elevation was not 1 1.0 feeL measured at the time of 12S exploration. TP-10 o so ,00 oa o so ioo -- TOPSOIL(6 inches). Medium stiff, brown SILT with sand os and cobbles (ML), minor gravel; moist, low dry strength, low plasticiry, sand is Y 2•5 fine to medium, gravel is fine to Moderate to severe caving \ Coarse - FILL. observed from 3.0 to 7.0 feet. a ^ light gray layer at 4.0 feet w 0 5.0 ' with large pieces of wood and debris at Z 5.0 feet a n o �.s boulder (3-foot diameter)at 7.0 feet � Z � � 0 0 � �o� Slow groundwater seepage � wood and concrete pieces at 10.0 feet observed ac �o.o feet. ' Surface elevation was not a Exploration terminated due to severe ��•0 measured at the time of ex loration. � caving at a depth of 1 1.0 feet. p � ' 12S m N O O T N Q _ Y 0 50 �OQ v EXCAVATED BY:Continental Dirt Constructan LOGGED BY:TAP COMPLETED:02/27/13 ¢ d z w a D(CAVATION MEfHOD:Uxkhoe(seereportfe#) N � � KCHA-29-01-02 TEST PIT a �DESIGN� W10700 Mendian Avenue North-Suite 210 � � Seattle WA 98133 MARCH 201 3 VANTAGE GLEN - MULTI-FAMILY RENTAL PROJECT , Off 206.638.9900 Fax 206.836.99D7 RENTON,wa FIGURE A-9 Z o �= u w Z � •MOISTURE DEPTH = MATERIAL DESCRIPTION >w � g CONTENT ' COMMENTS FEET � w o � N , �o�o� u TP'1 1 o Sa ,o0 °'0 - TOPSOIL(6 inches). Medium dense, light brawn, silty SAND o.s (SM); moist, fine, laminated pieces. 2'S dense to very dense; layers of orange at 2.5 feet No groundwater seepage observed to the depth explored. No caving observed to the depth I, s.o - explored. I Exploration completed at a depth of 5.0 5•0 � feet. Surface elevation was not �, I measured at the time of , exploration. 7.5 ; : 10.0 12.5 0 50 loo � Y rn � w H Q O H Z � d H ❑ u z u � w 0 0 W u 6 u � a � m� N O O T N a x u Y u EXCAVATED BY:CoMinental DiA Constructio� LOGGED BY:TAP COMPLEfED:02l27/13 a a � W a EXCAVATION MEfHOD:trackhoe(see repoA te�d) N � u KCHA-29-U1-02 TEST PIT a �DESIGN� W 10700 Meridian Avenue Nortn-Suite 210 VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT F Seattle WA 98133 MARCH 2O13 FIGU RE A-10 Off 206.838.9900 Fax 206.838.9901 RENTON,WA v x 0 z W a a � Q , ' ` Analytical Resources, Incorporated �� P�- � � � � �� Analytical Chemists and Consultants i ��-�,� - 2�- � t 13 January 2014 Tyler Pierce GeoDesign, Inc. 10700 Meridian Avenue North, Suite 210 Seattie, WA 98133 , I RE: Project: Samples Received 12l30/13 ARI Job No.: XS97 �I Dear Tyler: Please find enclosed the original Chain-of-Custody record (COC) and the final results for the samples from the project referenced above. Analytical Resources, Inc. {ARI) accepted four , soil samples on December 30, 2013. �,i The samples were analyzed for CEC and organic matter as requested. �I These analyses proceeded without incident of note. , An electronic copy of this report and all supporting raw data will remain on file with ARI. Should you have any questions regarding these results, please feel free to contact me at your convenience. Respectfully, ANALYTICAL RESOURCES, INC. `��C:( :�i%L� . Mark D. Harris `' Project Manager 206/695-6210 markhCa�arilabs.com www.arilabs.com eFile: XS97 Enc{osures MDH/mdh Page 1 of r f �� 4611 South 134th Place, Suite 100 • Tukwila WA 981 b8 • 206-695-6200 • 206-695-6201 fax ' Chain of Custody Record & Laboratory Analysis Request . ARI Assi ned Number: Turn-around Re uested: Pa e: of Analytical Resources,Incorporated , 9 �( ��i -� Q 9 � Analytical Chemists and Consultants �� ARI Ciient Company: Phone:(_-. ,� -, Date: Ice 461 1 South 134th Place, Suite 100 �;'c.��,.(;��_St��l 1.�� %(�.� T'-1 ;� - �t�:��: Present? � Tukwila,WA 98168 - 206-695-6200 206-695-6201 (fax) Client Contact: �� No.of � Cooler ��;: j �c-; l�(�-C-�.c:..- Coolers: �j' Temps: «-�� WWWarilabs.com Client Project Name: Analysis Requested Notes/Comments Client Project#: Samplers: i ; V Sample ID Date Time Matrix No.Containers i� � c� � ' �f�L � � "�� -�� 5 �`� 12j3�;jz��3 _� , f 1 ��?� � I X. � K�H.q 2Y-�.; �,-` < ;; ,��:w.-;i�<,,� : 't 1 ;�.� ( � u x K�H,� �� ' � ��' 3- - ��r ��1 ! � � �7-a3 i:�� ~ �l �i�::,'. _, � �� i�-t�,�1 z�_�.; �_; s �� ,� 1��r�:_.� 3� �� ;.:.� t � � � Comments/Special Instructions Relinquished by:. /'/ �' Received by: Relirquished by: Received by (Signature) C(.��.; ;-��/ (Sgnature) (Signature) (Signature) ="Y' Printed Name: Printed A�ame: Printed Name: Printed Name: Y'�f` 1 r' \/ l ��E.�K C�t`f..'��'k ..i ;�.� . Y��.�C�' k�^ t Company: " Gompany�: � �/' , Company: Company: (��=G�E-5�<�:ti IAL, j—''F'=-� � . Date 8 Time: Date 8 Ti e: � Date&Time: Date&Time r�,e I��ia/lr�� 1 z �,� � '� �1�r--- u.:o t.<,� ��"; Limits of Liability: ARI will perform all requested services in accordance with appropriafe methodology following ARI Sfandard Opeiating Procedures and the ARI Quality Assurance Program. This program ��;a meets standards lor the industry. The fotal liability of ARI,its officers,agents,employees,or successors,arising out of or in connection with the requested services,shall not exceed the Invoiced amount for ��''�•' said services. The acceptance by the dient of a proposal foi services by AR!release ARI from any liability rn excess thereof,not withstanding any provision to the contrary in any contract,purchase order or co- signed agreement between ARI and the Client. Sample Retention Policy: All samples submitted to ARI will be appropriately discarded no sooner than 90 days after receipt or 60 days after submission of hardcopy data,whichever is longer,unless alternate retention schedules have been established by work-order or contract. �,, �,�:�Iq�:eaf ��sQ�:e�s :�r�r��<<at�d .� �-� � �� Analytical Chemists and Consultanis � l��C��" L'�� Ir�� ' �, ARI Client:�z�j-'C :��.l-'��C 'vrl Project(Vame. COC No(s): �NP, Delivered by: Fed-Ex UPS Courier and Delivered Other. Assigned ARI Job No: �t T� � Tracking No: ✓ (�NA Preliminary Examination Phase: � Were intact,properlysigned and dated custody seafs aitached to the outside of io cooler? YES �Np Were custody papers included with the cooler? .................................... . � NO . .................... VVere custody papers properly filled out{ink,signed,etc.) ............................................ �E NO Temperature qf Cooler{s)(°C)(recommended 2.0-6.0°C for chemistry) � 7 �,: Time: �;�7�� + -f .C� C�' �-, ._ �, If cooler temperature is out of compliance fill out form 00070F Temp Gun ID#: �� % �S-}- / �' �� j� Cooler Accepted by: ��L Date: I-j--� �� Time: 4 , t�- Complete custody iorms and attach al!shipping documenfs �flg-tn Pha,se: Was a temperature blank included in the cooler?....................... ...... YES NO -' .......................... (_.- What kind of packing material was used? ... Bubble Wrap Wet Ice Gel Packs aggies Foam Block Paper Other: Was su�cient ice used (if appropriate)? ............. .............. . .. NA YES /Kl0 , .................................. ( � ; Were ail bottles sealed in individual plasticbags? ............................................................. C�ES._. `NO Did all bottles arrive in good condition(unbroken)?....................................................................... ��Y�S'1 �� Were all bottle labelscomplete and legible? .........._. .................. ...... . .._._ ..._....................... '�S Np \ Did the number of containers fisted on COC match with the number of containers received?................ 7�ES' NO Did all bottle labels and tags agree with custody papers? ..................... ........... ....................._ `!_ES: NO VVere aIf bottles used correct for the requested analyses?..................................._......................... ��5. NO Do any of the analyses(bottles) require preservation7(attach preservation sheet,excluding VOCs)... A� YES NO � - 4Nere ail VOC vials free of air bubbles? ................................................... ............ (NR� YES NO 1�Nas sufficient amount of sample sent in each bottle?............................................................. '.�Ey9 NO Date VOC Trip Blankwas made aYARI................................................................................. ;N�A,� 1Nas Sample Split by ARI : �� YES Date/Time: Equipment: Split by: S�mPles LogGe� by _ �� Date I � c'. 6 -�� Time /r'� � "`NoPify Projecf!Nlanager of discrepancies or concems'`" Sample ID on Bottle Sample ID on COC Sam le ID on Bottle Sample tD on COC Addifiona!NoPes,Discrepancies, d�Resolufions: B : Date: �mal.f+°+ir BE�?ble� Paat�ubb4as' tA E'Air�ubW�s Sroall�"sm" (<2 mm) ��7sn;Fl �-a rnm >4 mm Peabubbles� "pb"(2 to<4 mm) 9 A � _ �' �� r� � � � Large�"Ig"(4 to<6 mm) "-"".' --- "� Headspace�"hs" (>6 mm) 0016F Cooler Receipt Form Revision 014 3/2/10 . , ' ANALYTICAL Sample ID Cross Reference Report RESOURCES INCORPORATED ARI Job No : XS97 Client : D i Geo es gn Inc Project Event : N/A ' Project Name : N/A �r �ti Sample ID Lab ID LIMS ID Matrix Sample Date/Time VTSR l. KPG 18-01 B-2 S-4 XS97A 13-28262 Soil 12/30/13 15: 11 12/30/13 15: 12 2. KCHA 29-03 B-3 S-3 XS97B 13-28263 Soil 12/30/13 15: 11 12/30/13 15: 1% 3. KCHA 29-03 B-2 S-3 XS97C 13-28264 Soil 12/30/13 15: 11 12/30/13 15: 1� 4 . KCHA 29-03 B-1 S-3 XS97D 13-28265 Soil 12/30/13 15: 11 12/30/13 15: 1� � � Analytical Resources, Incorporated Analytical Chemists and Consultants C�ient: GeoDesign, Inc. AR! Job No.. XS97 Case Narrative 1. Four samples were submitted for analysis on December 31, 2013. 2. The samples were subm�tted for loss on ignifion determination according to ASTM D2974, Method A ar�d C. 3. The data is reporte�i in percent, an� is provided in summary tabfes. 4. There were no noted anomalies in the samples or methods on this project. Released by: ��--� � �'��'�" Date::. i�i�,i C'�'°c, r} �-�'1y Lea Technician Reviewed by: �� ''` Date: .F / � Geotechnic«!La aratory Manager 4611 South 134th Place, Suite 100 • Tukwifa WA 98168 • 206-695-6200 �=2D6-S95 6241 fa�c-; � Analytical Resources, Incorporated � Analytical Chemists and Consultants Data Reporting Qualifiers Effective 2/1412011 Inorganic Data U Indicates that the target analyte was not detected at the reported concentration * Duplicate RPD is not within established control fimits B Reported value is less than the CRDL but z the Reporting Limit N Matrix Spike recovery not within established control limits NA Not Applicable, analyte not spiked H The natural concentration of the spiked element is so much greater than the concentration spiked that an accurate determination of spike recovery is not possible � Analyte concentration is 55 times the Reporting Limit and the replicate control limit defaults to t1 RL instead of the normal 20% RPD Organic Data U Indicates that the target analyte was not detected at the reported concentration * Flagged value is not within established control limits B Analyte detected in an associated Method Blank at a concentration greater than one-half of ARI's Reporting Limit or 5% of the regulatory limit or 5% of the analyte concentration in the sample. J Estimated concentration when the value is less than ARI's established reporting limits D The spiked compound was not detected due to sample extract dilution E Estimated concentration calculated for an analyte response above the valid instrument calibration range. A dilution is required to obtain an accurate quantification of the analyte. Q Indicates a detected analyte with an initial or continuing calibration that does not meet established acceptance criteria (<20°/aRSD, <20%Drift or minimum RRF). Page 'I of 3 � � � Analytical Resources, Incorporated ' � Analytical Chemists and Consultants S Indicates an analyte response that has saturated the detector. The calculated concentration is not valid; a dilution is required to obtain valid quantification of the analyte NA The flagged analyte was not analyzed for NR Spiked compound recovery is not reported due to chromatographic interference NS The flagged analyte was not spiked into the sample M Estimated value for an analyte detected and confirmed by an analyst but with low spectral match parameters. This flag is used only for GC-MS analyses � M2 The samp�e contains PCB congeners that do not match any standard Aroclor I pattern. The PCBs are identified and quantified as the Aroclor whose pattern ! most closely matches that of the sample. The reported value is an estimate. N The analysis indicates the presence of an analyte for which there is presumptive evidence to make a "tentative identification" Y The analyte is not detected at or above the reported concentration. The reporting limit is raised due to chromatographic interference. The Y flag is equivalent to the U flag with a raised reporting limit. EMPC Estimated Maximum Possible Concentration (EMPC) defined in EPA Statement of Work DLM02.2 as a value "calculated for 2,3,7,8-substituted isomers for which the quantitation and /or confirmation ion(s) has signal to noise in excess of 2.5, but does not meet identification criteria" (DioxinlFuran analysis only) C The analyte was positively identified on only one of two chromatographic columns. Chromatographic interference prevented a positive identification on the second column P The analyte was detected on both chromatographic columns but the quantified values differ by z40% RPD with no obvious chromatographic interFerence X Analyte signal includes interference from polychlorinated diphenyl ethers. (Dioxin/Furan analysis only) Z Analyte signal includes interference from the sample matrix or perfluorokerosene ions. (DioxinlFuran analysis only) Page 2 of 3 SAMPLE RESULTS-CONVENTIONALS ANALYTICAL� XS97-GeoDesign Inc RESOURCE3 ' INCORPORATED Matrix: Soil Project: NA Data Release Authorized: Event: NA Reported: O1/13/14 Date Sampled: 12/30/13 � Date Received: 12/30/13 � Client ID: KPG 18-01 B-2 S-4 ARI ID: 13-28262 X397A Analyte Date Method Unita RL Sample Total Solids O1/03/19 SM2540G Percent 0.01 79. 97 010314#1 Cation Exchange Capacity O1/08/14 9080 meq/106 g 0.01 0. 88 010814#1 � RL Analytical reporting limit U Undetected at reported detection limit Soil Sample Report-XS97 SAMPLE RESULTS-CONVENTIONALS ANALYTICAL O XS97-GeoDesign Inc RESOURCES INCORPORATED Matrix: Soil Project: NA Data Release Authorized '; ,1 Event: NA Reported: O1/13/14 Date Sampled: 12/30/13 ,_) Date Received: 12/30/13 Client ID: KCHA 29-03 B-3 S-3 ARI ID: 13-28263 XS97B Analyte Date Method Units RL Sample Total Solids O1/03/14 SM2590G Percent 0.01 79. 96 010314#1 Cation Exchange Capacity O1/08/14 9080 meq/100 g 0.01 8. 63 010814#1 RL Analytical reporting limit U Undetected at reported detection limit Soil Sample Report-XS97 . . � �.'..�5�w�� SAMPLE RESULTS-CONVENTIONALS ANALYTICAL� XS97-GeoDesign Znc RESOURCES INCORPORATED � Matrix: Soil Project: NA Data Release Authorized: � Event: NA Reported• O1/13/14 �� a Date Sampled: 12/30/13 �� Date Received: 12/30/13 Client ID: KCHA 29-03 H-2 S-3 ARI ID: 13-28264 XS97C Analyte Date Method Unita RL Sample Total Solids O1/03/14 SM2540G Percent 0.01 81.41 010314#1 Cation Exchange Capacity O1/08/19 9080 meq/100 g 0.01 7.35 010814#1 RL Analytical reporting limit U Undetected at reported detection limit Soil Sample Re�ort-XS9? SAMPLE RESULTS-CONVENTIONALS ANALYTICAL� XS97-GeoDesign Inc RESOURCES INCORPORATED Matrix: Soil Project: NA Data Release Authorize : Event: NA Reported: O1/13/14 {� Date Sampled: 12/30/13 , Date Received: 12/30/13 Client ID: KCHA 29-03 B-1 S-3 ARI ID: 13-28265 XS97D Analyte Date Method Units RL Sample Total Solids O1/03/19 SM2590G Percent 0.01 80. 92 010319#1 Cation Exchange Capacity O1/08/19 9080 meq/100 g 0.01 7. 68 010814#1 RL Analytical reporting limit U Undetected at reported detection limit Soil Sample Report-XS97 .; �;� _� :, :;� � s.,: ; ��_ � �:s_ METHOD BLANK RESULTS-CONVENTIONALS ANALYTICAL� XS97-GeoDeaign Inc RESOURCES INCORPORATED i Matrix: Soil Project: NA Data Release Authorize : Event: NA Reported: O1/13/14 Date Sampled: NA ` � Date Received: NA Analyta Data Unite Blank QC ID Total Solids O1/03/14 Percent < 0.01 U ICB Cation Exchange Capacity O1/08/14 meq/100 g 0.02 PREP Soil Met!�od Blanic Report-XS9� s ANALYTICAL O GEOTECHNICAL ANALYSIS DATA SHEET RESOURCES Organic Matter by Method ASTM D2974 INCORPORATED �ata Release Authorized:� QC Report No: XS97-GecDesign Inc Reported: 01/08/14 Project: Cate Received: 12/30/13 1 Page 1 of 1 Client/ Date Analysis ARI ID Sampled Matrix Date Result KPG 18-01 B-2 S-4 12/30/13 Soil O1/06/14 10: 45 95. 38 XS97A 13-28262 KCHA 29-03 B-3 S-3 12/30/13 Soil O1/06/19 10:45 97 .31 XS97B 13-28263 KCHA 29-03 B-2 S-3 12/30/13 Soil O1/06/19 10:95 92.17 XS97C 13-28269 KCHA 29-03 B-1 S-3 12/30/13 Soil O1/06/14 10:95 41.87 'X.S97D 13-28265 Organic/Ash Content Burn Temperature 440 C Per ASTM D2974 I� R2port fcr XS9� GEOTECHNICAL ANALYSIS DATA SHEET ANALYTICAL � RESOURCES O Ash Content by Method ASTM D2974 INCORPORATED Data Release Authorized:� QC Report No: XS97-GeoDesign Inc Reported: O1/08/14 Project: Date Received: 12/30/13 Page 1 of 1 Client/ Date Analysis ARZ ID Sampled Matrix Date Result KPG 18-01 B-2 S-4 12/30/13 Soil O1/06/19 10:45 54 . 62 XS97A 13-28262 KCHA 29-03 B-3 S-3 12/30/13 Soil O1/06/19 10:95 52. 69 XS97B 13-28263 KCHA 29-03 B-2 S-3 12/30/13 Soil Ol/06/14 10:45 57 .83 XS97C 13-28264 KCHA 29-03 B-1 S-3 12/30/13 Soil O1/06/14 10:45 58.13 XS97D 13-28265 Organic/Ash Content Burn Temperature 440 C Per ASTM D2974 Rep��rt for XSy7 ANALYTICAL � GEOTECHNICAL ANALYSIS DATA SHEET RESOURCES O Total Solids by Method ASTM D2974 INCORPORATED Data R2lease Authoriz2d: 'L QC Report No: XS97-GeoDesign Inc �eported: O1/08/14 Project: 1=�ate Received: 12/30/13 Paqe 1 of 1 Client/ Date Analysis ARI ID Sampled Matrix Date Result KPG 18-01 B-2 S-4 12/30/13 Soil O1/06/14 10:45 79.69 XS97A 13-28262 KCHA 29-03 B-3 S-3 12/30/13 Soil O1/06/19 10:45 79.92 XS97B 13-28263 KCHA 29-03 B-2 S-3 12/30/13 Soil O1/06/14 10:45 61.30 XS97C 13-28264 KCHA 29-03 B-1 S-3 12/30/13 Soil 01/06/14 10 :95 80. 93 XS97D 13-28265 Re�ort for XS9i , t..� _ _ , �,�_� - � I � Analytical Resources, lncorporated Analytical Chemists and Consultants 17 January 2014 Tyler Pierce GeoDesign, Inc. 10700 Meridian Avenue North, Suite 210 Seattle, WA 98133 RE: Project: Samples Received 12/30113 ' ARI Job No.: XS97 Dear Tyler: Please find enclosed corrected reports for the samples from the project referenced above. As discussed, the original results for Organic Matter and Ash Content were incorrect due to an error in recording tare weights. The samples have been dried and re-weighed. An electronic copy of these reports will remain an file with ARI. Should you have any further questions, please feel free to contact me at your convenience. ', Respectfully, ANALYTICAL RESOURCES, INC. C,-( ✓)�� .�� Mar D. Harris C Project Manager 206/695-6210 I markh(a�arilabs.com www.arilabs.com eFile: XS97 Enclosures MDH/mdh Page 1 of �'',� 4611 South 134th Place, Suite 100 � Tukwila WA 98168 • 206-695-6200 � 20b-b95-6201 fax • ANALYTICAL� GEOTECHNICAL ANALYSIS DATA SHEET RESOURC ES Organic Matter by Method ASTM D2974 INCORPORATED Data Release Authorized:� QC Report No: XS97-GeoDesiqn Inc Reported: O1/17/14 Project: Date Received: 12/30/13 Page 1 of 1 Client/ Date Analysis ARI ID Sampled Matrix Date Result KPG 18-01 B-2 S-4 12/30/13 Soil O1/06/14 10: 45 0.40 XS97A 13-28262 KCHA 29-03 B-3 S-3 12/30/13 Soil O1/06/14 10:45 0.90 XS97B 13-28263 KCHA 29-03 B-2 S-3 12/30/13 Soil O1/06/14 10: 45 0.62 XS97C 13-28264 KCHA 29-03 B-1 S-3 12/30/13 Soil O1/06/14 10:45 0.67 XS97D 13-28265 Reported in � Organic/Ash Content Burn Temperature 440 C Per ASTM D2974 Report for XS9? , , : : ANALYTICAL � GEOTECHNICAL ANALYSIS DATA SHEET RESOURCES O Ash Content by Method ASTM D2974 INCORPORATED Data Release Authorizea:� QC Report No: XS97-GeoDesign Inc Reported: Ol/17/14 � Project: Date Received: 12/30/13 Page 1 of 1 Client/ Date Analysis ARI ID Sampled Matrix Date Result KPG 18-01 B-2 S-9 12/30/13 Soil Ol/06/14 10:45 99.60 XS97A 13-28262 KCHA 29-03 8-3 S-3 12/30/13 Soil Ol/06/14 10:45 99.10 XS97B 13-28263 KCHA 29-03 B-2 S-3 12/30/13 Soil Ol/06/14 10: 95 99.38 XS97C 13-28264 KCHA 29-03 B-1 S-3 12/30/13 Soil O1/06/19 10:45 99.33 XS97D 13-28265 Reported in $ Organic/Ash Content Burn Temperature 440 C Per ASTM D2974 ��_� ' I �_ , , Report �or XS9"1 f ANALYTICAL GEOTECHNICAL ANALYSIS DATA SHEET RESOURCES� Total Solids by Method ASTM D2974 INCORPORATED _ Data Release Authorized:� QC Report No: XS97-GeoDesign Inc Reported: 02/17/14 Project: Date Received: 12/30/13 Page 1 of 1 Client/ Date Analysis ARI ID Sampled Matrix Date Result KPG 18-01 B-2 S-4 12/30/13 Soil 01/06/19 10:45 79.64 XS97A 13-28262 KCHA 29-03 B-3 S-3 12/30/13 Soil 41/06/14 10: 95 �9.42 XS97B 13-28263 KCHA 29-03 B-2 S-3 12/30/13 Soil O1/06/14 10: 45 81.30 XS97C 13-28264 KCHA 29-03 B-1 S-3 12/30/13 Soil Ol/06/19 10: 45 80. 93 XS97D 13-28265 Reported in � � -, --� _ _� ..._ 0 x 0 z W a a a 1 Richard Martin Groundwater LLC February 23, 2014 Tom Tobin GeoDesign, Inc. 10700 Meridian Avenue North,#210 Seattle, WA 98133 RE: Stormwater Pond Infiltration and Mounding Analysis, King County Housing Authority Vantage Glen Development Project, Renton,Washington Hello Tom: This letter describes the mounding analysis performed to evaluate infiltration from the proposed stormwater detention pond and the potential impacts to adjacent steep slopes as part of the King County Housing Authority project to de�elop multi-family housing at the Vantage Glen Community in Renton,Washington. The mounding analysis was performed to meet requirements of the King County Surface Water Design Manual (2009)for design of infiltration facilities. The analysis was performed in general accordance with our proposal dated January 22, 2014, and the GeoDesign subconsultant agreement signed on February 19, 2014. The Vantage Glen Community is located south and west of the intersection of SE 180th Street and 105tn Place SE. The existing Vantage Glen Community consists of single-family manufactured homes and a community center. We understand the proposed development will be multi-family housing. As currently planned,the housing will include the construction of multi-story apartments and associated infrastructure(parking and utilities). We understand that significant site grading is anticipated to include excavations for below-grade parking under the buildings and construction of a stormwater management pond. The new development will be sited on a hill with steep slopes extending down to the existing Vantage Glen houses to the west and south, with an elevation difference of approximately 40 to 50 feet. Our understanding of the stormwater pond is based on drawings provided by GeoDesign that show site grading and the proposed location and size of the pond, information in the draft geotechnical report provided by you via email on February 18, 2014, and conversations with you the week of February 17 2014. We understand that the pond will not be lined. Although peak stormwater inflow rates to the �JOf1CI WefP D�OV�C�PC�, thP Inf01'^1at!O� (��f� npt �f1C�UC�P F`V��QE'�aDhc C�nWir!a !�n!'!j tY�_aP !jllri^,P Y�IP !'?� events. SUBSURFACE CONDITIUrs` Subsurface conditions at the proposed Vantage Glen Community development were interpreted based on the draft geotechnical report prepared by GeoDesign (2014), limited subsurface information from Richard Martin Groundwater LLC 206-979-1530 richard.martin.gw@gmail.com Richard Martin Groundwater LLC nearby sites, and our experience with similar sites in the area. Additional details on subsurface conditions are provided in the GeoDesign draft geotechnical report. Observed Soil Conditions For purposes of developing the mounding analysis,the soil profile was divided into two soil horizons,the shallow sandy soil and the underlying silty soil. The shallow sandy soil is described as clean to silty on the boring logs. No grain size analyses have been perFormed on the sand. The sand was observed to a depth of typically 15 to 20 feet below existing ground surface (bgs). The silty layer consists of very stiff to hard silt with varying amounts of sand and gravel. Groundwater Conditions Shallow groundwater was not observed in the explorations at the site. The main water table is presumed to be in a sandy soil underlying the silt at a depth of about 50 to 60 feet bgs. Seepage along the slopes was not observed during a windshield reconnaissance of the slopes above the existing Vantage Glen neighborhood,west and south of the proposed pond location. A drainage ditch runs along the south and west sides of the shopping center to the east of proposed pond location. The ditch may be the current representation of the stream that was in the area prior to development as noted on USGS Topographic Maps of the area. During the site visit,water was observed flowing in the ditch from east to west,then turning northward. The water flowed into a culvert north of the project site. Based a review of area topography, Google Earth, and observations during the site visit, it is estimated the water stage in the ditch was approximately elevation 378 feet with a ditch bottom of approximately elevation of 377 feet. It is not known if the ditch is lined or if water is infiltrating into the subsurface from the ditch. MOUNDING ANALYSIS A groundwater mounding evaluation was performed to assess potential impacts of infiltration from the proposed stormwater pond on groundwater levels in the vicinity of the development. Higher groundwater levels as a result of infiltration could reduce the effectiveness of the pond and result in seep/spring discharge along slopes to the south and west site. Discharge of groundwater along the slopes and excessive groundwater levels near the slopes could cause a reduction in slope stability. Conceptual model The model was developed to simulate water infiltrating from the pond into the sand layer intersected by the pond walls, above the silt layer that underlies the pond at approximately ele�ation 370 feet. The sand unit is assumed to extend to the slopes to the west and south above the existing Vantage Glen housing development. It is these slopes that are assumed to be at the most risk from infiltrating water. The proposed infiltration pond will be constructed in sandy soil with the base approximately 3 feet above the top of the underlying silt layer. It is anticipated that water in the pond will seep out through 2 RMG024 Richard Martin Groundwater LLC the sides and bottom of the pond into the sandy soil. The water will percolate downward to the top of the silt layer then move laterally along the top of the silt towards the slopes. Depending on the rate of infiltration from the Fred Meyer ditch,the movement to the east may be limited by the percolating water from the ditch. Groundwater Flow Model An analytical mounding analysis was performed by simulating stormwater infiltration from the proposed for two different pond stages scenarios,and the potential rise of a hypothetical shallow water table above the silt layer using the groundwater flow program, MODFLOW. For the purposes of this model, a conservative approach was used assuming water infiltrating from the pond and the drainage ditch was directly to the water table;that is no unsaturated zone was considered that would be normally expected to slow the downward movement of water and allow for lateral spreading of water before reaching the water table. A 1000-foot by 1000-foot model domain was set up around the site with boundaries to the north,west, and south representing the sand/silt interface along the slopes at elevation 370 feet and a boundary to the east representing the drainage ditch. The stormwater pond was located based on the project drawings. The model domain was subdivided into a grid of 50 rows and 50 columns on 20-foot spacing. Figure 1 shows the mounding model domain,grid, and boundary conditions. Aquifer parameters for the model were developed based on the soil descriptions and results of the infiltration testing performed at the proposed pond location, and our experience with 5imilar soil. An initial water table representing peak wet season conditions was established at 0.5 feet above the silt layer(elevation 370.5 feet). Because of the uncertainty in aquifer hydraulic parameters of the soils at the site, multiple model runs were performed modifying aquifer parameters over a reasonable expected range of values. Aquifer parameters evaluated included hydraulic conductivity,storage coefficient, and the hydraulic connection between the pond and drainage ditch and the underlying soil. The analyses indicated that the model is most sensitive to the hydraulic conductivity of the sandy soil. As a result,the highest anticipated hydraulic conductivity based on the results of the infiltration testing(25 feet per day) was used in the infiltration scenarios as a conservative approach. Evaluation of Potential Moundin� ; As indicated above, stage hydrographs were provided for peak storm events. Instead two infiltration scenarios were developed to represent long-term, non-peak stormwater runoff and short-term peak runoff. The first scenario consisted of a low stage in the infiltration pond representing a 30-day period of steady precipitation without storm events. The stage in the pond was maintained at elevation 374 feet for the 30 day period (1 foot above the proposed base of pond). 3 RMG024 Richard Martin Groundwater LLC The second scenario in�olved a period of peak precipitation storm events where the pond has filled to the design peak stage of elevation 377 feet(the elevation of the flow control structure) and is maintained at that stage for a period of 7 days. The results of the mounding are presented in Figures 2 and 3. In both cases, groundwater mounding occurs below the base of the pond with mounding reaching the base of the pond. The results also show the movement of groundwater laterally towards the slopes. For the first scenario,groundwater mounding near the slopes shows a rise of approximately 1 foot within about 20 feet of the face of the slope. For the second scenario,groundwater mounding near the slopes shows a slightly steeper groundwater gradient near the slope than the first scenario with a rise of approximately 1.5 feet within about 40 feet of the face of the slope. CONCLUSIONS The potential development of shallow water table as a result infiltration from the pond should be anticipated. The height and extent of the groundwater mounding will be affected by the distribution of hydraulic conductivity of the sandy soils underlying the pond and to a lesser extent the hydraulic connection between the pond and the underlying soil. The mounding results indicate that groundwater is likely to rise to the base of the infiltration pond. Lateral spreading of the groundwater mound is likely to reach the steep slopes to the west and south of the pond above the existing Vantage Glen Community. A groundwater rise of up to 1.5 feet adjacent to the slopes was estimated with the groundwater model,which may decrease slope stability. We recommend the results of the mounding analysis be reviewed by a licensed geotechnical engineer to assess the potential reduction in slope stability on slopes to the south and west of the site. In addition to the potential slope stability issues,the results of the groundwater mounding should be compared to the location and depth of proposed subsurface structures for the development. If subsurface structures and facilities are located near the simulated groundwater mounds, remedial measures may be necessary to reduce potential impacts of groundwater on the structures and facilities. We understand that other stormwater management approaches, including permeable pavement may be used for the development. Any additional facilities or structures that enhance infiltration of stormwater at a rate greater than natural background may increase groundwater mounding and exacerbate the impacts described above. Prior to design of additional infiltration facilities we ' recommend that additional mounding should be performed. Because of the potential risk of groundwater mounding as a result of construction of the stormwater mound,we recommend establishing a groundwater monitoring program following construction to observe shallow groundwater conditions. , LIMITATIONS The opinions,conclusions, and recommendations provided in this report are based on information provided in the GeoDesign draft geotechnical report, observed conditions during the site visit, project 4 RMG024 Richard Martin Groundwater LLC plan drawings for grading showing the Iocation and size of the infiltration pond, and professional experience with mounding analyses for similar types of projects in King County. The analyses and conclusions presented in this report were prepared in accordance with generally accepted professional hydrogeologic principles and practice in this area at this time. No other warranty, either express or implied, is made. The scope of services did not include any environmental assessment or evaluation regarding the presence or absence of wetlands or hazardous or toxic material in the soil, surface water, groundwater, or air,on or below or around the site. This report was prepared solely for the use of GeoDesign and the King County Housing Authority to meet the minimum requirements of the King County Surface Water Design Manual for the proposed stormwater pond as part of the Vantage Glen Community project. If you have any questions or comments, please contact me at 206-979-1530 or at Richard.martin.�w@�mail.com. Sincerely, �:-�� V`Jash� ;:� �t � ;f'�` � ��°�'`, f�, � �•�' � 11 (1 i�� -- �,f- Hycrogeologist �'� ��'�q 337 �'` �J2��Z0�� S�d Geo�o �`�C�^1"Cj �l0"1!� "� ,� i a v,3; fl Richard J. Martin, L.H.G. Richard Martin Groundwater LLC Enclosures: Figure 1—Model Domain, Grid, and Boundary Conditions Figure 2—Steady State Groundwater Flow Hydraulic Head Contours Figure 3—Results of Dewatering After Two Weeks 5 RMG024 Richard Martin Groundwater LLC REFERENCES GeoDesign, 2014, Draft Report of Geotechnical Engineering Services, prepared for King County Housing Authority. King County, 2009, Kin�Countv Surface Water Desi�n Manual. Washington State Department of Ecology, 2012, Stormwater Mana�ement Manual for Western WashinQton, Publication No. 12-10-030. 1 6 RMG024 �. ,- _ � -�` _ � = � � ` _ . �.. _ /s�� - - _ a � � ._.. I: iP'��' K ;J _ — MODEL GRID , � �- �;� = 3. �_ _ � - �;: ;« -. A- - _ � .� �� ;a - - Each model cell is 20 feet by 20 feet �� ` �� - . .. .F- _-¢ : �. " ". � � � ' �_ _ " t i_ --��-r_ , , ---� ---�- - - � � �� -� �. , , �F _T-�-, - - - ', � �-' �T -- ' - � �-- _ � ; , --1 -- - - - - � _ ,�:, � � � - - _ __ _ � �� _� � , � - _ �_ __�- - - - " � .< ; � -�-t- � , y � _ . _ ir� & � - - �-+- �� - �r � r :,� �-�-� �� -- --� �. - .. - �4 � ` # �°' . 3 � �� -� � r �& � ; �� I .�°*. �t` '�� 3 �� - �I ,•�� ' �,�� _� �� '� I � � � -'-�- _ �- - --`-r�—' -�--r-r--r i-'-�---1 � � � � ' � t � i , .... . - �— -I - �---? - � - - - - �, i , .� --}--f-i i ,_ _ _ _ , -- 0 500 feet ._ , � � ' __,__ � � _ � ��_,� _ �--- , __ -_1__;_ ,� =.- ; �-- � �_ � -- , _ _ -;_ -�-�- _ �-}-' �--� � �+�--�-- - �- -- - - � - _ � � � ;� Approximate Scale k� _ -� _ . � ; -� - - + � -- : -.-� F � - � < < , , _ _ __ � _ _ i � �'� - � -,-- - - , -t--`�� _ - � ; , , : ; , ; , H � —r- - - - - - �,� -r r'— -- , :. - -r �; —� -f- -+- '�- = - — _ _ - - � _- -- �- " ., '� �,�� — -- +rt- � --}-+ � ' � ':x- � t _ f-+ - - - � '-'` � -- � -- — - - � , � , �� '. �_ � � -+ ��-T- � 1 ' - - � '� �' � _ Proposed Stormwater Pond "� � ` .�- -+-- -F- ; --;- r- _�. �_ � = �' ; , ' --�-��- � 1-` '- ��_ .. - �" �- , `� j � ,-+ ' -1-�~�- —�—r-; �,'- - �--�- `�_ .��-- �. - � ` '� ,, _-�-+ - � � �— --� --'-- � - — �—---1— � ��° -_ I x � � _ Drain bounda re resentin �� --� _ . - �� , - rY P 9 , ; r �� --- - �-��:�-� -�� -��, � sand/silt interface on slope a i•, + ; ; ' , }- � �� , �3a T � T ' - — - ',`� �-�a� - - +— — I ��_ ��-J----� �_ �-�- � � � � '�� ' ��` - ' � '-� ' r = �-1� -� - �-I-- � �- -�� _ - River boundary representing I�I � � .�_ � ' �- �� - ri--=-� �'_ -t`_Y � - I = �: - �__ �� ;._. drainage ditch � _ � � � . _ _ �� -- _ -- �= ----�, - � - � �--�—� � , : _ e �. . . :� ,� �� ..� � -` ; _ �. � . s�� -�� ` ' � � ✓:: '� - i�� x�-�:¢ � +--� �`X �� ' - "_ •� � ��,�,•- �;� - - _ � " - - �- � � �� , - - - - s -�" _ �'"s`� �`` ..� '�. -• � - . _ - `� ,a '� � = _ �. �� - � _ � � �� . r -- � � -�. �� °��,�,a � - _- -�'-"1 � §, � --t��. . rs: . . �, � �+ • ` � � _ _ -x . �-� � . -= - f._ . . � � .. � z Base map adapted from Google Earth �, MODEL DOMAIN AND GRID c� � February 23, 2014 m Richard Martin King County HA Vantage Glen Community - GeoDesign Inc. � " Groundwater LLC � Renton, Washington FIGURE 1 � - � - _.�� M- �.� I_ � �: ` a� . s , �!j�� ` � _, �_ _ - _��_ �� i��i E f - � � MODEL SCENARIO _ � =� = �� - � �� . Baseline wet season with 30 days of pond stage � � � c -� .� y �� y � � ;� � � �T s _. � at elevation 374 feet �, :_ - � - - , �; _ �= : .: _ , � _� . �� ` Contours show feet of groundwater mounding �� _ '{ � -�s� : - - - �,, k � A� _ i,_F _O � Y � x �� `�` �`�` � - Groundwater Mounding �� -� .� ��, �-� � _ ,,,� �_ � - 1 .5 Contour in Feet :�� °�� o-`�� '" � _ �'� (contour interval = 0.5 feet) � : .,�� , E � .. . - ;� � -� . R { � � ,TM - t.:� � � �� , "� e,-� _ �� g �� *��= � = � 0 500 feet - h - `�' �� `� - = ti Approximate Scale � _r : � =v�� h _ � � _ � � � - , � �� _�� - � _. ` -�� - �� - ��. �� `- ` '� Proposed Stormwater Pond -� - '� � -�� -� �� - .�, � -� � � �- ' - � -�=�-��"�� - � �� - �`��` _ _ _ � a " �,s`eeAc� F+—:'' _ a�-k clr ''.- ��--r.' �.,�+��'�.._ '} � - _ _ __.. _ , A < : �i�� .xk�'�-_L�y. " " � • �" •-��`- •. -_� .: . � Y ' r. � � � . .- . . - ' ..._ t_. ...- �A=- . _. � .... � � k1� _' _ — � ' _ _ . `� Drain bounda re resentin _. y�,` ., � - ��-�� . _ _ _ .. � �� -� E- �� ' . . _ rY P 9 ��: - � - - = sand/silt interface on slope � � � �� - _ =. � .��€;� .� ��_ : _ M - - � , _ �; , � �' � � � _ � �`` �� ,. �� - - � ,� - � �' =� y � -- � � � � � _ �� - _ _ � _ - �._� �� ` � � ' � � �� River boundary representing ; � ,._ a �-` _ �_ � � �._ �_ � - drainage ditch ,� � �.�" � ��, �� _ _ �� ` 7 � � � � ��=�s ��,�� - - �i��; �� „ _ �- � � , �' �;�� ., _ __ E � _� � ` _ � . � __ _ _ � � � � � - ,. � _ - . . � _ � ��',,-� . . ` �= � � Base map adapted from Google Earth „ CONTOURS OF GROUNDWATER MOUNDING AFTER 30 DAYS OF ASSUMED BASELINE WET SEASON c� � February 23, 2014 m Richard Martin King County HA Vantage Glen Community - GeoDesign Inc. N � c�ounawate��c Renton, Washington FIGURE 2 ,: �. � � �_� � :�� , � ��- z � �- � _- ` " � ° - __ =��- p�-'='� '�� - �„�� -� � _� :�� --_ � � MODEL SCENARIO - � �: _ � . _ _ T �- � � i� Peak pond stage at elevation 377 feet followed by -� � - - � _ � : . � �-=� - � 7 days of pond stage at elevation 374 feet , � �� ,� - � - � - : _. - _ � . � �� _ � � � _ � �� x - rt � � � � � � � - Contours show feet of groundwater mounding � � - ''�` �_ � -_�_ � � F _ _ � � �� s ' �`� `�` � � � Groundwater Mounding �� -�.s �� ,,� � � � �� = � 1 .5 Contour in Feet _ � �� _ �:.� _.� �. � �� -- � (contour interval = 0.5 feet} - �: � � �� : _ _ - � __ �� ' �;" � - _ � ,. - � �� .� �,- _ �� - � ��'�`'� �� 0 500 feet �.. ti - ;2, Approximate Scale -`= .,�y -_ _ � �`= p`' �� - =� '';�� ; - � r }:, �� - � �� . -,�� . . �� - � � �� -'� ��-�`��'�� - ` Pr sed Stormwater Pond _ - - � '� �� ,,� � � opo � _ - -- � , . -� � � k � �- < _ _ ._ � �.-. : �= �� - �� .�� - � � = �� 3�.�_ �'-� -�� _ � � - �=�� . � _ � 3 - ' w-� - '�? - " � Drain boundary representing �� , � �-� � � ,� .� rt ��; . , � _ -�� _ �� sandlsilt interFace on slope € `� � � a� _ � ��` � �, -- _ €,_ - -� �_ = ` � _ _ :� � � � l' � � - � ; __ River boundary representing � 4 e _ �, � �� =� � �' � - �� - - drain ditch _ � � � r�� _ � �< � �_ _� age -: � � _ ,� �^� __ ,� '� . � _ �� ` �� " , �� y�� -� -:, �._ _ �"��_ � ��. -� � - � ' � � -� „`. �'' -'`� � � z�:� �� ` " � _ ��-��9 ...,� � _ ��-- � .� _ - -�,. ; _ _ � , � - , ,. - , �: � � � � _ " ` - _ � � - - : �� V. _ _ - �-- � _ �. _ �� _ - � , �. _ «;n _, __... -_�. -�. � -:. _ �� . . ._ _ - x � Base map adapted from Google Earth „ CONTOURS OF GROUNDWATER MOUNDING 7 DAYS AFTER PEAK POND STAGE c� c m Richard Martin King County HA Vantage Glen Community - GeoDesign Inc. February 23, 20�4 w Groundwater LLC Renton, Washington FIGURE 3 N � } Z O oc U Q , , , � � � � � ACRONYMS I ADS advanced drainage system ASTM American Society for Testing and Materials ATB asphalt-treated base BGS below ground surface CEC cation exchange capacity EPA U.S. Environmental Protection Agency ! g gravitational acceleration (32.2 feet/second�) ' gpm gallons per minute GPS global positioning system '� HMA hot mix asphalt H:V horizontal to vertical IBC International Building Code KCHA King Counry Housing Authority kN/mZ kilonewtons per square meter MCE maximum considered earthquake MSE mechanically stabilized earth OSHA Occupational Safety and Health Administration pcf pounds per cubic foot pci pounds per cubic inch psf pounds per square foot PVC polyvinyl chloride SPT standard penetration test SWDM Surface Water Design Manual WSS Washington Standard Specifications for Road, Bridge, and Municipal Construction (2012) �_�Jv t5�� KCHA-29-03:02241 4 E 0 U U C .� OA .N N 'D O N ❑0 3 3 3 k ff ; �� ; , Appendix D Construction Stormwater Polution Pre�ention Plan Uantage Point Apartments Technical Information Report Appendix D n Stormwater Pollution Prevention Plan �� For ', Vantage Point Apartments Prepared For Northwest Regional Office 31 y0 160th Avenue Southeast Bellevue, WA 98008-5452 425-649-7000 Owner Developer Operator/Contractor King County Housing � TBD Authority Project Site Location 17901 lOSth Place Southeast, Renton WA, 98055 Certified Erosion and Sediment Control Lead TBD SWPPP Prepared By Christopher Borzio, PE KPFF Consulting Engineers 1601 Fifth Avenue, Suite 1600 Seattle WA, 98101 SWPPP Preparation Date 12/09/?013 Approximate Project Construction Dates Start: TBD Finish: TBD NOT UPDATED FOR ASBUILT � n Contents 1.0 Introduction...............................................................................................................................l 2.0 Site Description ........................................................................................................................3 2.1 Existing Conditions...........................................................................................................3 2.2 Proposed Construction Activities......................................................................................3 3.0 Construction Stormwater BMPs...............................................................................................5 3.1 The 12 BMP Elements.......................................................................................................5 3.1.1 Element No. 1 —Mark Clearing Limits..............................................................5 3.1.2 Element No. 2—Establish Construction Access ................................................5 3.1.3 Element No. 3—Control Flow Rates..................................................................6 3.1.4 Element No. 4—Install Sediment Controls........................................................F 3.1.5 Element No. 5 —Stabilize Soils..........................................................................� 3.1.6 Element No. 6—Protect Slopes..........................................................................� 3.1.7 Element No. 7—Protect Drain Inlets..................................................................� 3.1.8 Element No. 8—Stabilize Channels and Outlets................................................�� 3.1.9 Element No. 9—Control Pollutants....................................................................�� 3.1.10 Element No. 10—Control Dewatering..............................................................�� 3.1.11 Element No. 11 —Maintain BMPs ....................................................................9 3.1.12 Element No. 12—Manage the Project.............................................................10 4.0 Construction Phasing and BMP Implementation ...................................................................1� 5.0 Pollution Prevention Team ......................................................................................................15 5.1 Roles and Responsibilities...............................................................................................15 5.2 Team Members................................................................................................................I 5 6.0 Site Inspections and Monitoring.............................................................................................17 6.1 Site Inspection.................................................................................................................17 6.1.1 Site Inspection Frequency ................................................................................17 6.1.2 Site Inspection Documentation.........................................................................17 6.2 Stormwater Quality Monitoring......................................................................................18 6.2.1 Turbidity...........................................................................................................18 6.2.2 pH .....................................................................................................................18 7.0 Reporting and Recordkeeping ................................................................................................21 7.1 Recordkeeping.................................................................................................................21 7.1.1 Site Log Book...................................................................................................21 7.1.2 Records Retention.............................................................................................21 7.1.3 Access to Plans and Records............................................................................21 7.1.4 Updating the SWPPP........................................................................................21 7.2 Reporting.........................................................................................................................2? 7.2.1 Discharge Monitoring Reports .........................................................................2? 7.2.2 Notification of Non�6��D�T�.r......................................................,, FOR ASBUIL�r ;; n AppendixA— Site Plans.........................................................................................................22 Appendix B —Construction BMPs.........................................................................................23 Appendix C — Alternative BMPs............................................................................................25 AppendixD— General Permit ................................................................................................27 Appendix E—Site Inspection Forms (and Site Log)..............................................................29 Appendix F—Engineering Calculations.................................................................................37 Appendix A Site plans ■ Vicinity map (with all discharge points) ■ Site plan with TESC measures Appendix B Construction BMPs ■ Possibly reference in BMPs, but likely it will be a consolidated list so that the applicant can photocopy from the list from the SWMM. Appendix C Alternative Construction BMP list ■ List of BMPs not selected, but can be referenced if needed in each of the 12 elements Appendix D General Permit _ Appendix E Site Log and Inspection Forms Appendix F Engineering Calculations (if necessary) ■ Flows, ponds, etc... NOT UPDATED FOR ASBUILT »> Stormwafer Po!lution Prevention Plan 1.0 Introduction This Stormwater Pollution Prevention Plan (SWPPP) has been prepared as part of the NPDES stormwater permit requirements for the Vantage Point Apartments construction project in Renton, Washington. The site is located at 17901 lOSth Place Southeast, Renton, Washington 98055 at the intersection of Southeast 108th Street and lOSth Place Southeast. The existing site is a 5.2-acre grassed lot with no surface improvements. The proposed development consists of two apartment buildings connected by a central common space, a rain garden, a detention pond, and landscaping. The north building is five levels and the south building is four levels, each including one level of underground parking. There are two surface parking lots, one associated with the north building and the other with the south. Construction activities will include excavation, grading, installation of on-site services/utilities, and construction of a four- and five-story apartment building. The purpose of this SWPPP is to describe the proposed construction activities and all temporary and permanent erosion and sediment control (T'ESC) measures,pollution prevention measures, inspection/monitoring activities. and recordkeeping that will be implemented during the proposed construction project. The objectives of the SWPPP are to: 1. Implement Best Management Practices (BMPs) to prevent erosion and sedimentation, and to identify, reduce, eliminate, or prevent stormwater contamination and water pollution from construction activity. ?. Prevent violations of surface water quality, ground water quality, or sediment management standards. 3. Prevent, during the construction phase, adverse water quality impacts, including impacts on beneficial uses of the receiving water by controlling peak flow rates and volumes of stormwater runoff at the Permittee's outfalls and downstream of the outfalls. This SWPPP was prepared using the Washington State Department of Ecology (Ecology) SWPPP Template downloaded from the Ecology website on December 9, 2013. This SWPPP was prepared based on the requirements set foRh in the Construction Stormwater General Permit, Stormwater Management Manual for Western Washington (SWMMWW 2005). The report is divided into seven main sections with several appendices that include stormwater related reference materials. The topics presented in the each of the main sections are: ■ Section 1 — INTRODUCTION. This section provides a summary description of the project and the organization of the SWPPP document. ■ Section 2—STTE DESCRIPTION. This section provides a detailed description of the existing site conditions, proposed construction activities, and calculated stormwater flow rates for existing conditions and post-construction cond��T �JP�/�TED FOR ASBUILT � Sformwater Pollution Prevention Plan ■ Section 3 —CONSTRUCTION BMPS. This section provides a detailed description of the BMPs to be implemented based on the 12 required elements of the SWPPP (SWMMWW 2005). ■ Section 4—CONSTRUCTION PHASING AND BMP IMPLEMENTATION. This section provides a description of the timing of the BMP implementation in relation to the project schedule. • Section 5 —POLLUTION PREVENTION TEAM. This section identifies the appropriate contact names (emergency and non-emergency), monitoring personnel, and the on-site temporary erosion and sedimentation control inspector • Section 6—INSPECTION AND MONITORING. This section provides a description of the inspection and monitoring requirements, such as the parameters of concern to be monitored, sample locations, sample frequencies, and sampling methods for all stormwater discharge locations from the site. ■ Section 7 —RECORDKEEPING. This section describes the requirements for documentation of the BMP implementation, site inspections, monitorina results, and changes to the implementation of certain BMPs due to site � factors experienced during construction. Supporting documentation and standard form� are provided in the followinQ Appendices: Appendix A—Site plans Appendix B —Construction BMP� Appendix C —Alternative Construction B�9 P I i st Appendix D—General Permit Appendix E— Site Loa and Inspecti�n F�rn�� I � ,_..I � � , � I NOT UPDATED FOR ASBUILT z Stormwater Pollution Prevention Plan 2.0 Site Description 2.1 Existing Conditions The project site is located at 17901 lOSth Place Southeast, Renton, Washington 98055. The existing site topography is the result of historical legal mining operations. The site is a relatively level grass covered bench projecting approximately 200 feet southward and westward from Southeast 108th Street and lOSth Place Southeast. Grades on the bench vary from 5 percent to 25 percent sloping toward the roadway. Outward of the bench is a steep slope at upwards of 50 percent down to a neighboring community on Southeast 181st Street. The project does not propose any clearing on the steep slope. Stormwater sheets off of the existing site toward the City of Renton (City) owned collection system in Southeast 108th Street and lOSth Place S��u�l��.��. }�lllli�� .`_�Il�t-�l(t�� 11��I11 I�1C �I�� 1� ��t�� l�� I}l� C��Ctl��il �A�(�111 �U I}l� t�� lf �]1��. 2.Z Proposed Construction Acti�ities The site area including the steep slope is 5.243 acres. �u��l tlle linzit ut� �li�t�uhance ar�a f�,r th� project is 3.689 acres. The proposed development includes two apartment buildings connertc�l by a central common space. The north building is five levels and the south building is four levels, each including one level of underground parking. There are two surface parking lot�. ��ne associated with the north building and the other with the south. Stormwater runoff from the proposed development will be collected in a series of catch basins and swales. Target pollution generating surfaces will be treated by an on-site rain garden to receive Enhanced Basic Water Quality Treatment The treated runoff is then routed to a Level Two detention pond to protect downstream fish bearing streams. The detention pond outlets to the City owned storm drain ii� lOSth Place Southeast. There is no change to the existing site discharge point. All runoff from property within city ROW that is within the limit of disturbance is considered bypass flow. "I hr detention fa�ilit� i� �ie�i��nc�l ��it(� �i �1��n�trram ��,int ��f��mplianc� that ,�c��unt� f��r thi� bypass flo�� . The schedule and phasing of BMPs during construction is provided in S�rti��n -�.0. Stormwater runoff volumes were calculated using the King County Runoff Time Series (KCRTS J. The temporary sedimentation pond that will be used during construction was designed using the 2-year storm event since construction will not occur over a long time-frame (approximately one year). The detention pond was designed using KCRTS. The live storage detention volume was designed by matching pre- and post-construction flows and durations for 50 percent of the ?-}c�ir flow and the 50-year flow. The pre ��,n�tructi��n f7c�«�� are n��,�leleci a� t��rrstcci. T�1� �(1��V\ lll" �llllllll.Ull�� j�'l.tl�� I��".tl��lll�� 11� .tl'��1�: � � ��I:l� �Il�' �.�1��'LI', -ti i ,I��f�� NOT UPDATE FOR ASBUIL Stormwater Pollution Prevention Plan ■ Percent impervious area before construction: 0 % ■ Percent impervious area after construction: 64 % ■ Disturbed area during construction: 4.01 acres ■ Disturbed area that is characterized as impervious (i.e., access roads, staging, parking): 0 acres ■ 2-year stormwater runoff peak flow prior to construction (existingj: 0.16 cfs ■ 10-year stormwater runoff peak flow priar to construction (existing): 0.29 cfs ■ 2-year stormwater runoff peak flow during construction: 0.63 cfs ■ 10-year stormwater runoff peak flow during construction: 0.75 cfs ■ 2-year stormwater runoff peak flow after construction: 0.08 cfs ■ 10-year stormwater runoff peak flow after construction: 0.15 cfs All stormwater flow calculations are provided in TIR. NOT UPDATED FOR ASBUILT � Stormwater Pollution Prevention Plan 3.0 Construction Stormwater BMPs 3.1 The 12 BMP Elements 3.1.1 Element No. 1 —Mark Clearing Limits To protect adjacent properties and to reduce the area of soil exposed to construction, the limits of construction will be clearly marked before land-disturbing activities begin. Trees that are to be preserved, as well as all sensitive areas and their buffers, shall be clearly delineated, both in the field and on the plans. In general, natural vegetation and native topsoil shall be retained in an undisturbed state to the ma�imum extent possible. The BMPs relevant to marking the clearing limits that will be applied for this project include: BMP C101: Preserving Natural Vegetation BMP C 103: High Visibility Plastic or Metal Fence Alternate BMPs for marking clearing limits are included in Appendix C as a quick reference tool for the on-site inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix D). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix D), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix C after the first sign that existing BMPs are ineffective or failing. 3.1.2 Element No. 2—Establish Construction Access Construction access or activities occurring on unpaved areas shall be minimized; yet where necessary, access points shall be stabilized to minimize the tracking of sediment onto public roads, and wheel washing, street sweeping, and street cleaning shall be employed to prevent sediment from entering state waters. All wash wastewater shall be controlled on site. The specific BMPs related to establishing construction access that will be used on this project include: BMP C105: Stabilized Construction Entrance Alternate construction access BMPs are included in Appendix C as a quick reference tool for the ', on-site inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix D). ' To avoid potential erosion and sediment control issues that may cause a violation(s) of the ' NPDES Construction Stormwater permit (as provided in Appendix D), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix C after the first sign that existing BMPs are ineffective ar failing. � NOT UPDATED FOR ASBUILT 5 Stormwater Pollution Prevention Plan 3.1.3 Element 1\0. 3— Control Flo�� Rates In order to protect the properties and waterways downstream of the project site, stormwater discharges from the site� will be controlled. The specific BMPs for flow control that shall be used on this project include: BMP C241: Temporar} Sediment Pond Alternate flow control BMPs are included in Appendix C as a quick reference tool far the on-site inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix D). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix D), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternati��c BMPs listed in Appendix C after the first sign that existing BMPs are ineffective or failing. In general, discharge rates of stormwater from the site will be controlled where increases in impervious area or soil compaction during construction could lead to downstream erosion. ��r where necessary to meet lor�il �i_�c nr� ,t�,rm��itcr �ii.ch�ir��c rcyuirr�n�nt� i�.��. cii�rhar��c t�� combined sewer systems j. 31.4 Element No. 4—Install Sediment Contr��l�5 All stormwater runoff from disturbed areas shall pass thi��u�.h ��n apprupriaic ��iin�cn� ��c�»��;�i BMP before leaving the construction site or prior to being discharged to an infi Itr.��i��n i�a�i I it� . Z'lle SPeC1f1C BMPS [�� hC ll��lj f��f ��IITI��i��lll�` ��l�llllClll i?Il t�ll� �ll��.��C�( I11��U�j�: BMP C233: Silt I :n�c BMP C241: Temporary Sediment Pon�l Alternate sediment control BMPs are includ��i in Appendix C a� u yuick rel�crence tool i�r th� on-site inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Pernut(Appendix V�. To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix D), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix C after the first sign that existing BMPs are ineffective or failing. In addition, sediment will be removed from paved areas in and adjacent to construction work areas manually or using mechanical sweepers, as needed, to minimize tracking of sediments on vehicle tires away from the site and to minimize washoff of sediments from adjacent streets in runoff. Whenever possible, sediment laden water shall be discharged into on-site, relatively level, vegetated areas (BMP C240 paragraph 5, a e 4-102). NC��UPDATED FOR ASBUILT 6 Stormwater Po!lution Prevention Plan In some cases, sediment discharge in concentrated runoff can be controlled using permanent stormwater BMPs (e.g., infiltration swales, ponds, trenches). Sediment loads can limit the effectiveness of some permanent stormwater BMPs, such as those used for infiltration or �I biofiltration; however, those BMPs designed to remove solids by settling (wet ponds or detention ', ponds) can be used during the construction phase. When permanent stormwater BMPs will be I used to control sediment discharge during construction, the structure will be protected from , excessive sedimentation with adequate erosion and sediment control BMPs. Any accumulated sediment shall be removed after construction is complete and the permanent stormwater BMP will be restabilized with vegetation per applicable design requirements once the remainder of the � site has been stabilized. The following BMPs will be implemented as end-of-pipe sediment controls as required to meet pernutted turbidity limits in the site discharge(s). Prior to the implementation of these technologies, sediment sources and erosion control and soil stabilization BMP efforts will be maximized to reduce the need for end-of-pipe sedimentation controls. BMP C250: Construction Stormwater Chemical Treatment (implemented only with prior written approval from Ecology). '- BMP C251: Construction Stormwater Filtration 31.5 Element No. 5—Stabilize Soils Exposed and unworked soils shall be stabilized with the application of effective BMPs to prevent erosion throughout the life of the project. The specific BMPs for soil stabilization that shall be used on this project include: BMP C120: Temporary and Permanent Seeding BMP C 122: Nets and Blankets BMP C 123: Plastic Covering BMP C125: Topsoiling BMP C140: Dust Control Alternate soil stabilization BMPs are included in Appendix C as a quick reference tool for the on-site inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix D). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix D), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the altcrnative BMPs listed in Appendix C after the first sign that existing BMPs are ineffective or failing. NOT UPDATED '' FOR ASBUILT ' � I Stormwater PoJlution Prevention Plan 2 days during the wet season (October 1 to April 30). Regardless of the time of year, all soils shallbe stabilized at the end of the shift before a holiday or weekend if needed based on weather forecasts. In general, cut and fill slopes will be stabilized as soon as possible and soil stockpiles will be temporarily covered with plastic sheeting. All stockpiled soils shall be stabilized from erosion, protected with sediment trapping measures, and, where possible, be located away from storm drain inlets, waterways, and drainage channels. 3.1.6 Element No. 6—Protect Slopes All cut and fill slopes will be designed, constructed, and protected in a manner that minimizes erosion. The following specific BMPs will be used to protect slopes for this project: BMP C200: Interceptor Dike and Swale BMP C201: Grass-Lined Channels BMP C204: Pipe Slope Drains BMP C208: Triangular Silt Dike (Geotextile-Encased Check Dam) Alternate slope protection BMPs are included in Appendix C as a quick reference tool for the on- site inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix D). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix D), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix C after the first sign that existing BMPs are ineffective or failing. 3.1.7 Element No. 7—Protect Drain Inlets All storm drain inlets and culverts made operable during construction shall be protected to prevent unfiltered or untreated water from entering the drainage conveyance system. However, the first priority is to keep all access roads clean of sediment and keep street wash water separate from entering storm drains until treatment can be provided. Storm Drain Inlet Protection (BMP C220) will be implemented for all drainage inlets and culverts that could potentially be impacted by sediment-laden runoff on and near the project site. The following inlet protection measures will be applied on this project: �� BMP C220: Storm Drain Inlet Protection ��I If the BMP options listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix D), or if no BMPs are listed above but deemed necessary durin construction, the Certified Erosion and Sediment N�T UPDATED FOR ASBUILT s Stormwater Pollution Prevention Plan Control Lead shall implement one or more of the alternative BMP inlet protection options listed ' in Appendix C. ' 3.1.8 Element No. 8—Stabilize Channels and Outlets Where site runoff is to be conveyed in channels, or discharged to a stream or some other natural drainage point, efforts will be taken to prevent downstream erosion. The specific BMPs for channel and outlet stabilization that shall be used on this project include: BMP C202: Channel Lining BMP C209: Outlet Protection Alternate channel and outlet stabilization BMPs are included in Appendix C as a quick reference tool for the on-site inspector in the event the BMP(s) listed above are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit (Appendix D). To avoid potential erosion and sediment control issues that may cause a violation(s) of the NPDES Construction Stormwater permit (as provided in Appendix D), the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs listed in Appendix C after the first sign that existing BMPs are ineffective or failing. 3.1.9 Element No. 9—Control Pollutants All pollutants, including waste materials and demolition debris, that occur onsite shall be handled and disposed of in a manner that does not cause contamination of stormwater. Good housekeeping and preventative measures will be taken to ensure that the site will be kept clean, well organized, and free of debris. If required, BMPs to be implemented to control specific sources of pollutants are discussed below. BMP C 151: Concrete Handling BMP C152: Sawcutting and Surfacing Pollution PreventionThis section of the report shall be expanded by the contractor after workplan and construction methods are established. 3.1.10 Element No. 10— Control Dewatering Foundation, vault, and trench de-watering water, which have similar characteristics to stormwater runoff at the site, shall be discharged into a controlled conveyance system prior to discharge to a ', sediment trap or sediment pond. Channels must be stabilized, as specified in Element No. 8. ' 3.1.11 Element No. 11 —Maintain BMPs All temporary and permanent erosion and sediment control BMPs shall be maintained and repaired as needed to assure continued performance of their intended function. Maintenance and repair NOT UPDATED FOR ASBUILT y Stormwater Pollution Prevention Plan shall be conducted in accordance with each particular BMP specification (attached). Visual monitoring of the BMPs will be conducted at least once every calendar week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the site becomes inactive, and is temporarily stabilized, the inspection frequency will be reduced to once every month. All temporary erosion and sediment control BMPs shall be removed within 30 days after the final site stabilization is achieved or after the temporary BMP are no longer needed. Trapped sediment shall be removed or stabilized on site. Disturhed s�il resulting from removal of BMPs or vegetation shall be permanently stabilized. 3.1.12 Element No. 12—Manage the Project Erosion and sediment control BMPs for this project have been designed based on the � following principles: ■ Design the project to fit the existing topography, soils, and drainage patterns. ■ Emphasize erosion control rather than sediment control. ■ Minimize the ertent and duration of the area e�posed. ■ Keep runoff velocities low. ■ Retain sediment on site. ■ Thoroughly monitor site and maintain all ESC measures. ■ Schedule major earthwork during the dry season. In addition, project management will incorporate the key components listed below: As this project site is located west of the Cascade Mountain Crest, the project will be managed according to the following key project components: Phasing of Construction ■ The construction project is being phased to the extent practicable in order to prevent soil erosion, and, to the maximum extent possible, the transport of sediment from the site during construction. ■ Revegetation of exposed areas and maintenance of that vegetation shall be an integral part of the clearing activities during each phase of construction, per the Scheduling BMP (C 162). NOT UPDATED FOR ASBUILT �o Stormwater Po!lution Prevention Plan Seasonal Work Limitations ■ From October 1 through April 30, clearing, grading, and other soil disturbing activities shall only be permitted if shown to the satisfaction of the local permitting authority that silt-laden runoff will be prevented from leaving the site through a combination of the following: ❑ Site conditions including existing vegetative coverage, slope, soil type, and proximity to receiving waters; ❑ Limitations on activities and the extent of disturbed areas; and ❑ Proposed erosion and sediment control measures. ■ Based on the information provided and/or local weather conditions, the local permitting authority may expand or restrict the seasonal limitation on site disturbance. ■ The following activities are e�empt from the seasonal clearin� and grading limitation�: ❑ Routine maintenance and necessary repair of erosion and sediment control BMPs; ❑ Routine maintenance of public facilities or ekistinv utility �tructure� that do not expose the ��il ��i- rc�,ult in the i�cm��al ��l thc ��c��etati�� cover to soil; and ❑ Aetivities where there is 100 percent infiltration of surface ��ater runoff within the site in appro��ed and installed erosion and sediment control facilities. � �'��I�t�lll.l�l�ill A11!�i � ;Illill'� �lll�.� l )I�I��I� .�ll��l�ijl�ll��;l� � � .tf�� l�t� ��.�. �_l}��li . �_ . :�llli.li� A\ 1!�l L;'i��.:��. �':fl'�1 �i �l��;l;'�.l��l; ��I� and the local jurisdiction in preparing this SWPPP and scheduling the construction work. Inspection and Monitoring ■ All BMPs shall be inspected, maintained, and repaired as needed to assure continued performance of their intended function. Site inspections shall be conducted by a person who is knowledgeable in the principles and practices of erosion and sediment control. This person has the necessary skills to: NOT UPDATED FOR ASBUILT 11 Stormwater Pollution Prevention Plan ❑ Assess the site conditions and construction activities that could impact the quality of stormwater, and ❑ Assess the effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. ■ A Certified Erosion and Sediment Control Lead shall be on-site or on-call at all times. ■ Whenever inspection and/or monitoring reveals that the BMPs identified in this SWPPP are inadequate, due to the actual discharge of or potential to discharge a significant amount of any pollutant, appropriate BMPs or design changes shall be implemented as soon as possible. Maintaining an Updated Construction SWPPP ■ This SWPPP shall be retained on-site or within reasonable access to the site. ■ The SWPPP shall be modified whenever there is a change in the design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the state. ■ The SW'PPP shall be modified if, during inspections or investiQations conducted by the owner/operator, or the applicable local or state regulatory authority, it is determined that the SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. The SWPPP shall be modified as necessary to include additional or modified BMPs designed to correct problems identified. Revisions to the SWPPP shall be completed within seven (7) days following the inspection. NOT UPDATED FOR ASBUILT �� Stormwater Pollution Prevention Plan ■ stabilization products: TBD ■ Install ESC measures: TBD ■ Install stabilized construction entrance: TBD ■ Begin clearing and grubbing: TBD NOT UPDATED FOR ASBU I LT �3 Stormwater Pollution Prevention Plan 5.0 Pollution Prevention Team 5.1 Roles and Responsibilities The pollution prevention team consists of personnel responsible for implementation of the SWPPP, including the following: ■ Certified Erosion and Sediment Control Lead (CESCL) —primary contractor contact, responsible for site inspections (BMPs, visual monitoring, sampling, etc.); to be called upon in case of failure of any ESC measures. ■ Resident Engineer—For projects with engineered structures only (sediment ponds/traps, sand filters, etc.): site representative for the owner that is the project's supervising engineer responsible for inspections and issuing instructions and drawings to the contractor's site supervisor or representative. ■ Emergency Ecology Contact— individual to be contacted at Ecology in case of emergency. ■ Emergency Owner Contact—individual that is the site owner or representative of the site owner to be contacted in the case of an emergency. ■ Non-Emergency Ecology Contact—individual that is the site owner or representative of the site owner than can be contacted if required. ■ Monitoring Personnel —personnel responsible for conducting water quality monitoring; for most sites this person is also the Certified Erosion and Sediment Control Lead. 5.2 Team Members Names and contact information for those identified as members of the pollution prevention team are provided in the following table. Tide Name(s) Phone Number Certified Erosion and Sediment Control Lead(CESCL) TBD - Resident Engineer - - Emergency Ecology Contact - - Emergency Owner Contact - - Non-Emergency Ecology Contact - - Monitoring Personnel TBD FOR ASBUILT 15 Stormwater PoJlution Prevention Plan 6.0 Site Inspections and Monitoring Monitoring includes visual inspection, monitoring for water quality parameters of concern, and documentation of the inspection and monitoring findings in a site log book. A site log book will be maintained for all on-site construction activities and will include: �, ■ A record of the implementation of the SWPPP and other permit requirements; I ■ Site inspections; and �, ■ Stormwater quality monitoring. ' For convenience, the inspection form and water quality monitoring forms included in this SWPPP include the required information for the site log book. This SWPPP may function as the site log book if desired, or the forms may be separated and included in a separate site log book. However, if separated, the site log book but must be maintained on-site or within reasonable access to the site and be made available upon request to Ecology or the local jurisdiction. 6.1 Site Inspection All BMPs will be inspected, maintained, and repaired as needed to assure continued performance of their intended function. The inspector will be a Certified Erosion and Sediment Control Lead (CESCL) per BMP C 160. The name and contact information for the CESCL is provided in Section 5 of this SWPPP. Site inspection will occur in all areas disturbed by construction activities and at all stormwater discharge points. Stormwater will be examined for the presence of suspended sediment, turbidity, discoloration, and oily sheen. The site inspector will evaluate and document the effectiveness of the installed BMPs and determine if it is necessary to repair or replace any of the BMPs to improve the quality of stormwater discharges. All maintenance and repairs will be documented in the site log book or forms provided in this document. All new BMPs or design changes will be documented in the SWPPP as soon as possible. 6.1.1 Site Inspection Frequency Site inspections will be conducted at least once a week and within 24 hours following any discharge from the site. For sites with temporary stabilization measures, the site inspection frequency can be reduced to once every month. 6.1.2 Site Inspection Documentation The site inspector will record each site inspection using the site log inspection forms provided in Appendix E. The site inspection log forms may be separated from this SWPPP document, but NOT UPDATED FOR ASBUILT » Stormwater Pollution Prevention Plan will be maintained on-site or within reasonable access to the site and be made available upon request to Ecology or the local jurisdiction. 6.2 Stormwater Quality Monitoring 6.2.1 Turbidity Turbidity sampling and monitoring will be conducted during the entire construction phase of the project. Samples will be collected daily at Catch Basin (CB) No. 8056 (as shown on site survey) at the sediment pond point of connection to lOSth Place Southeast. If there is no flow in this catch basin, the attempt to sample will be recorded in the site log book and reported to Ecology in the monthly Discharge Monitoring Report (DMR) as "No Discharge". Samples will be analyzed far turbidity using the EPA 180.1 analytical method. The key benchmark turbidity value is 25 nephelometric turbidity units (NTU) for the downstream receiving water body. If the 25 NTU benchmark is exceeded in any sample collected from CB No. 8056, the following steps will be conducted: 1. Ensure all BMPs specified in this SWPPP are installed and functioning as intended. 2. Assess whether additional BMPs should be implemented, and document modified BMPs in the SWPPP as necessary. 3. Sample discharge daily until the discharge is 25 NTU or lower. If the turbidity exceeds 250 NTU at any time, the following steps will be conducted: L Notify Ecology by phone within 24 hours of analysis (see Section 5.0 of this SWPPP for contact information). 2. Continue sampling daily until the discharge is 25 NTU or lower Initiate additional treatment BMPs such as off-site treatment, infiltration, filtration and chemical treatment within 24 hours, and implement those additional treatment BMPs as soon as possible, but within a minimum of 7 days. 3. Describe inspection results and remedial actions taken in the site log book and in monthly discharge monitoring reports as described in Section 7.0 of this SWPPP. 6.2.2 pH Sampling and monitoring for pH will occur during the phase of construction when concrete pouring will be conducted until fully cured(3 weeks from last pour) and discharges are documented to be below pH 8.5. Samples will be�1�e�l��E�i�sedimentation pond prior to FOR ASBUILT � ,� Stormwater Pollution Prevention Plan discharge to surface water. Samples will be analyzed for pH using a calibrated pH meter and recorded in the site log book. The key benchmark pH value for stormwater is a maximum of 8.5. If a pH greater than 8.5 is measured in the sedimentation trap/pond(s) that has the potential to discharge to surface water, the following steps will be conducted: 1. Prevent(detain) all discharges from leaving the site and entering surface waters or storm drains if the pH is greater than 8.5 2. Implement CO2 sparging or dry ice treatment in accordance with Ecology BMP C252. 3. Describe inspection results and remedial actions that are taken in the site log book and in monthly discharge monitoring reports as described in Section 7.0 of this SWPPP. NOT UPDATED FOR ASBUILT 19 Stormwater Po!luti�n Prevention Plan 7.0 Reporting and Recordkeeping 7.1 Recordkeeping 7.1.1 Site Log Book A site log book will be maintained for all on-site construction activities and will include: ■ A record of the implementation of the SWPPP and other pemut requirements; ■ Site inspections; and ■ Stormwater quality monitoring. For convenience, the inspection form and water quality monitoring forms included in this SWPPP include the required information for the site log book. '�� 71.2 Records Retention Records of all monitoring information (site log book, inspection reports/checklists, etc.), this Stormwater Pollution Prevention Plan, and any other documentation of compliance with permit requirements will be retained during the life of the construction project and for a minimum of 3 years following the termination of permit coverage in accordance with permit condition SS.C. 7.1.3 Access to Plans and Records The SWPPP, General Permit, Notice of Authorization letter, and Site Log Book will be retained on site or within reasonable access to the site and will be made immediately available upon request to Ecology or the local jurisdiction. A copy of this SWPPP will be provided to Ecology within 14 days of receipt of a written request for the SWPPP from Ecology. Any other information requested by Ecology will be submitted within a reasonable time. A copy of the SWPPP or access to the SWPPP will be provided to the public when requested in writing in accordance with permit condition SS.G. 7.1.4 Updating the SWPPP In accordance with Conditions S3, S4.B, and S9.B.3 of the General Permit, this SWPPP will be modified if the SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site or there has been a change in design, construction, operation, or maintenance at the site that has a significant effect on the discharge, or potential for discharge, of pollutants to the waters of the State. The SWPPP will be modified within seven days of determination based on inspection(s) that additional or modified BMPs are necessary to correct problems identified, and an updated timeline for BMP implementation will be prepared. NOT UPDATED FOR ASBUILT �'� z� Stormwater Po!lution Prevention Plan 7.2 Reporting 7.2.1 Discharge Monitoring Reports If cumulative soil disturbance is smaller than 5 acres: Discharge Monitoring Report (DMR) forms will not be submitted to Ecology because water quality sampling is not being conducted at the site. If cumulative soil disturbance is 5 acres or larger: Discharge Monitoring Reports (DMRs) will be submitted to Ecology monthly. If there was no discharge during a given monitoring period, the Permittee shall submit the form as required, with the words "No discharge" entered in the place of monitoring results. The DMR due date is 15 days following the end of each month. 7.2.2 Notification of Noncompliance If any of the terms and conditions of the pernut is not met, and it causes a threat to human health or the environment, the following steps will be taken in accordance with permit section SS.F: 1. Ecology will be immediately notified of the failure to comply. 2. Immediate action will be taken to control the noncompliance issue and to correct the problem. If applicable, sampling and analysis of any noncompliance will be repeated immediately and the results submitted to Ecology within 5 days of becoming aware of the violation. 3. A detailed written report describing the noncompliance will be submitted to Ecology within 5 days, unless requested earlier by Ecology. In accordance with permit condition S2.A, a complete application form will be submitted to Ecology and the appropriate local jurisdiction (if applicable) to be covered by the General Permit. I l �=J 1 J I ✓f 1 . . FOR ASBUII Stormwater Pollution Prevention Plan '' Appendix B — Construction BMPs The following includes a list of the BMPs to be implemented on the site. BMP C 101: Preserving Natural Vegetation BMP C103: High Visibility Plastic or Metal Fence BMP C 105: Stabilized Construction Entrance BMP C241: Temporary Sediment Pond BMP C233: Silt Fence BMP C?41: Temporary Sediment Pond BMP C 120: Temporary and Permanent Seeding BMP C122: Nets and Blankets BMP C123: Plastic Covering BMP C 125: Topsoiling BMP C 140: Dust Control BMP C200: Interceptor Dike and Swale BMP C201: Grass-Lined Channels BMP C204: Pipe Slope Drains BMP C208: Triangular Silt Dike (Geotextile-Encased Check Dam) BMP C220: Storm Drain Inlet Protection BMP C202: Channel Lining BMP C209: Outlet Protection BMP C 151: Concrete Handling BMP C 152: Sawcutting and Surfacing Pollution Prevention NOT UPDATED FOR ASBUILT z� 4.1 Source Control BMPs BMP C101: Preserving Natural Vegetation Purpose The purpose of preserving natural vegetation is to reduce erosion where�er practicable. Limiting site disturbance is the single most effective n�ethc�d for reducing erosion. For example, conifers can hold up to about 50 percent of al) rain that falls during a storm. Up to 20-30 percent of thi� rain may never reach the ground but is taken up by the tree or evaporates. Another benefit is that the rain held in the tree can be released slo��rly to the ground after the stor�n. Conditions of L%se • Natural vegetation should be preser��ed on steep slopes_ near perennial and intermittent �vatercourses or s„ale�, and on buildin�� sites in wooded areas. • As required by 1oca1 gover�lments. � Desig� atid Natural veg�etation can he pre�er��ed in natiir��l cl�tn;,�: ��r as incli� idual Installation trees, shrubs and vines. Specificatio��s The preservation of ind��-idual plants �s more dit�ficult because heav� equipment is generally used to remove un�vanted vegetation. The point.; to remember when attempting to save individual plants are: • ts the plant worth saving? Consider the location, species, size, a�e. vigor, and the work involved. Local governments may also have ordinances to save natural vegetation and trees. • Fence or clearly mark areas around trees that are to be saved. 1t i� preferable to keep ground disturbance a�-ay from the trees at least a� far out as the dripline. Plants need pri�tection from three kind� of injurie�: • Co�rsti�i�ctior� E��irr��rne�7t - This injur�� can be above or belo�� The ground level. Damage results from scarring, ctitting of roots, and compaction of the soil. Placing a fenced buffer zone around plants to be saved prior to construction can prevent construction equipment injuries. • Grade C/ranges - Changing the nahiral ground level will alter grades, which affects the plant's abilit}� to obtain the necessary air, water, and minerals. Minor fills usually do not cause problems although sensitivity between species does vary and should be checked. Trees can tolerate fill of 6 inches or less. For shrubs and other plants, the fill should be less. ��Vhen there are inajor changes in grade, it may become necessary tc� supply air to t e o t a his can be done by placing a layer of gravel and � �y� ��ots befare the fill is made. A tile FOR ASBUILT 4-2 Volume !!—Construction Stormwater Pollution Prevention February 2005 system protects a tree fi-om a raised grade. The tile s_ystem should be laid out on the original grade leading from a dry well around the tree trunk. The system should then be covered with small stones to allow air to circulate over the root area. Lowering the natural �-ound level can seriously damage trees and shrubs. The highest percentage of the plant roots are in the upper 12 inches of the soil and cuts of only 2-3 inches can cause serious injury. To protect the roots it may be necessary to terrace the immediate area around the plants to be saved. If roots are exposed, construction of retaining �valls may be needed to keep the soil in place. Plants can also be preser��ed by lea��ing them on an undisturbed, gently sloping motmd. To increase the chances for survival, it is best to limit grade changes and other soil disturbances to areas outside the dripline of the ptant. • Erca��atiorrs - Protect trees and other plants when excavating for drainfields, power, water, and sewer lines. Where possible, the trenches should be routed around trees and large shn�bs. When this is not possible, it is best to tunnel under them. This can be done with hand tools or with power augers. If it is not possible to route the trench around plants to be saved, then the following should be observed: Cut as few roots as possible. When you have to cut, cut clean. Paint cut root ends with a wood dressing like asphalt base paint. Backfill the trench as soon as possible. � Tunnel beneath root systems as close to the center of the main trunk to preserve most of the important feeder roots. Some problems that can be encountered witl� a few specific trees are: • Maple, Dogwood. Red alder, Vl�`estern hemlock, Western red cedar, and Douglas fir do not readily adjust to changes in environment and special care should be taken to protect these trees. • The windthrow hazard of Pacitic silver fir and madronna is high, while that of Western hemlock is moderate. The danger of windthrow increases ��here dense stands have been thinned. Other species (unless they are on shallow, wet soils less than 20 inches deep) have a low windthrow hazard. • Cottonwoods, maples, and «�illows have «�ater-seeking roots. These can cause trouble in sewer lines and infiltration fields. On the other hand, they thrive in high moisture conditions that other trees would not. • Thinning operations in pure or mixed stands of Grand fir; Pacifi� �il�er fir, Noble��S�lc�-t��J,e�.tern r�d cedar. ��'estern he�»lock_ CU FOR ASBUILT - - _ _------ -- -- ---__ - February 2005 Volume 1!— Constructron Stormwater PoHution Prevent�on 4-3 Aacific dog�cood, and Red alder can cau�e serious disease problems. Disease can become established through dama�ed limbs, tnink�. rc�ots. and freshly cut stumps. Diseaseci and �reakenc�j trec;s are also susceptible to insect attack. ,��aintena�rce • Inspect flagged and/or fenced areas regularly to i��ake sure fla�gii�g or Stu�rdards fencing has not been removed or damaged, 1f the flagging or fencing has been damaged or visibility reduced, it shall be repaired or replaced immediately and visibility restored. • If tree roots have been exposed or injured, "prune" cleanly ��ith an appropriate pruning saw or lopers directly above the damaged roott and recover with native soils. Treatment of sap flowing trees (fii-_ hemlock. pine, soft maples) i� noi a�1��itcd a� sa}� forni� a natural l�calin� barrier. NOT UPDATED I, FOR ASBUILT 4-4 Volume !J- Construction Stormwater PoUution Prevention February 2005 BMP C103: High Visibility Plastic or Metal Fence Pinpose Fencing is intended to: (1) restrict clearing to approved limits; (2) prevent disturbance of sensitive areas, their buffers, and other areas required to be left iindisturbed; (3} li�nit constntction traffic to designated construction entrances or roads; and, (4) protect areas wi�ere marking with survey tape may not provide adequate protection. Conditio�ts of Use To establish clearing limits, plastic or metal fence may be used: • At the boundary of sensitive areas, their buffers, and other areas required to be left uncleared. • As necessary to control vehicle access to and on the site. Desig�� and • High visibility plastic fence shall be composed of a high-density Ifistallatio►i polyethylene material and shall be at least four feet in height. Post, Specificutia�s for the fencing shaU be steel or wood and placed every 6 feet on center{maximum) or as needed to ensure rigidity. The fencing shall be fastened to the post every six inches with a polyethylene tie. On long continuous lengths of fencing, a tension wire or rope shall be used as a top stringer to prevent sagging between posts. The fencc color shall be high visibiliry orange. The fence tensil�� :�re��1� �h�lll be 360 lbs./ft. using the ASTM D-�595 testing methocl. • Metal fences shall be designed and installed accardir�� te IIIe manufacturer's specificationc. • Metal fences shall be at least ? feet high and mu�t be h��7h1} � isible. • Fences shall not be wired or stapled to trees. 1Naintenarrce • If the fence has been damaged or visibility reduced, it �hall h� S�n�rda�•ds repaired or replaccd imt�iediatel�� and ��i�ibilit�� rest��r�•�i_ NOT UPDATED FOR ASBUILT 4-6 Vofume !1- Constructrcn Stormwater Pollution Prevention Fehruary 2005 BMP C105: Stabilized Construction Entrance Purpose Construction entrailces are stabilized to reduce the amount of sediment transported onto paved roads by vehicles or equipment by constructing a stabilized pad of quany spalls at entrances to construction sites. Conditions of Use Construction entrances shall be stabilized wherever txaffic will be leavin�T a constnicti�n site and traveling on paved roads or other paved areas within 1,000 feet of the site. On large commercial, highway, and road projects, the designer should include enough extra materials in the contract to allow for additional stabilized entrances not shown in the initial Construction SWPPP. It i� difficult to detern�ine exactly w�he"re access to these projects will take place; a�lditi��nal niaterials ��ill enable the contractur to install them ��vherr needed. Design and • See �-igure 4.2 tor deta�ls. Note: t}�e 100� minin�um len�th ��f the Insta/lation entrance shall be reduced to the maximum practicable size when the Specifications size or confi�uration of the site does not allow the full length (I OU�i. • A separation geotextile shall be placed under the spalls to prevent fine sediment from pumping up into the rock pad. The geotextile shall meet the following standards: Grab Tensile Strength (ASTM D4751) 200 psi min. ! Grab Tensile Elongation (ASTM D4632) 30% max. i Mullen Burst Strength (ASTM D3786-80a) 400 psi min. � AOS (ASTM D4751) 20-45 (U.S. standard sieve size) � • Consider early installation of the first lift of asphalt in areas that will paved; this can be used as a stabilized entrance. Also consider the installation of excess concrete as a stabilized entrance. During lar��: concrete pours, excess concrete is often available for this purpose. • Hog fuel (waod-based mulch) may be substituted for or combined ��ith quam� spalls in areas that will not be used for pennanent roads. Hog fiiel is generally less effective at stabilizing construction entrances and should be used only at sites «�here the amount of traffic is very limited. Hog fuel is not recommended for entrance stabilization in urban areas. The effecti��eness of hog fuel is highly variable and it generally requires more maintenance than quarry spalls. The inspector mav at any time require the use of quarry spalls if the hog fuel is not preventing sediinent from being tracked onto pavement or if thc hc�;� fuel is being carried onto pavement. Hog fuel is prohibited in permanent roadbeds because organics in the subgrade soils caiisc degradation of the subgrade support over time. • Fencing {see BMPs C 103 and C 104) shall be installed as necessa�� tu restrict traffic to the construction entranc�. NOT UPDATED FOR ASBUILT 4-8 Volume !I— Construction Stormwafer Pollution Prevention February 2005 • Whenever possible, the entrance shall be constructed on a finn, compacted subgrade. This can substantially increase the effectiveness i of the pad and reduce the need for maintenance. Maintenance • Quarry spalls (or hog fuel) shall be added if the pad is no longer in Standards accordance with the specifications. • If the entrance is not preventing sediment from being tracked o►lto pavement,then alternative measures to keep the streets free of sediment shall be used. This may include street sweeping, an increase in the dimensions of the entrance, or the installation of a wheel wash. • Any sediment that is tracked onto pavement shall be removed by shoveling or street sweeping. The sediment collected by sweeping shall be removed or stabilized on site. The pavement shall not be cleaned by washing down the street, except when sweeping is ineffective and there is a threat to public safety. If it is necessary to wash the streets, the construction of a small sump shall be considered. The sediment would then be washed into the suinp ��l�ere it can be cantrolled. • Any quarry spalls that are loosened from the pad, which end up on the roadway shall be removed immediately. • If vehicles are entering or exiting the site at points other than the construction entrance(s), fencing (see BMPs C103 and C104) shall be installed to control traffic. • Upon project completion and site stabilization, all construction accesses intended as permanent access for maintenance shall be ermanentl stabilized. Oriveway shap meel the requiremants of the perm%ting agency M is recommended that Me entrance be nowned so thal•u�c'1 p�ad drams olf Ihe patl Ei�s��o9 � r °o. i � ! Insta�driveway wlvert it Ihere is a roadSiGe ditch present �'-8"quarry spalls Geotextile 5�� \� � �t2"mla th�ckness�- � Provde�ull w�dUi ol �ngress/eg�ess area Figure 4.2-Stabilized Construction Entrance NOT UPDATED FOR ASBUILT February 2005 Volume ll- Consfrucfion Stormwafer Pol/ution Prevention 4-9 BMP C241: Temporary Sediment Pond Purpose Sediment ponds remove sediment from runofti originating from disturbed areas of the site. Sediment ponds are typicaily designed to remove sediment no smalier than medium silt (0.02 mm). Consequently, the�� usually reduce turbidity only slightly. Conditions of Use Prior to leaving a construction site, stormwater runoff must pass throu�l� a sediment pond or other appropriate sedinlent removal best managemel�t practice. A sediment pond shall be used where the contributing drainage area is 3 acres or more. Ponds must be used in conjunction with erosion control practices to reduce the amount of sediment flowing into the basin. Design and • Sediment basins must be installed only on sites where failure of the Installation structure would not result in loss of life, damage to homes or Specifrcati�ns buildings, or interruption of use or service of public roads or utilitic;. Also, sediment traps and ponds are attractive to children and can be very dangerous. Compliance with local ordinances regarding healtl� and safety must be addressed. If fencing of the pond is required, tlle type of fence and its location shall be shown on the ESC plan. • Structures having a maximum storage capacity at the top of the da�� <�f 10 acre-ft (435,6Q0 ft') or more are subject to the VVashin�ton Da�l� Safety Regulations (Chapter 173-175 WAC). • See Figure 4.24, Figure 4.25, and Figure 4.26 for details. • If pennanent runoff control faciJities are part of the project, they should bc used for sediment retention. The surface area requirements of the sediment basin must be met. This may require enlarging thc pern�anent basin to comply with the surface area requirements. If a pern�anent control structure is used, it may be advisable to partially restrict the lower orifice with gravei to it�crease residence time w-hile still allowing dewatering of the basin. • Use of infiltration facilities for sedimentation basins durina � construction tends to clog the soils and reduce their capacity to , infiltrate. If infiltration facilities are to be used, the sides and bottom � of the facility must only be rough excavated to a minimum of 2 feet above final grade. Final grading of the infiltration facility shall occur only when all co»tributing drainage areas are fully stabilized. The infiltration pretreatment facility should be fully coilstructed and used with the sedimentation basin to help prevent clogging. • Detern�ining Pond Geometry Obtain the discharge from the hydrologic calculatia�is of the peak flow for the 2-year runoff event (Q�). The 10-year peak flow shall be used if the project size, expected timintr and duration of construction, or downstream conditions �varrant a higher level of protection. If no hydrologic ��is�Pr��i�� Rational Method may be used. FOR ASBUILT February 2005 Volume 1!- Constructron Stormwater Pollution Preventron 4-905 Determine the required s�►rface area at the top o1 the riser pipe with the equation: S4 = � x Q�:'0.00096 or 2080 square feet per cfs of inflow See BMP C240 for more inforn�ation on tl�e derivation of the surface area calculation. The basic geometry of the pond can now be determined using the following design criteria: I • Required surface area SA (froni Step 2 abo�•e) at top of riser. I • Vlinimum 3.5-foot depth from top of riser to bottom of pond. • 1•4aximum 3:1 interior side slopes and maximum 2:1 exterioi slope,. The interior slopes can be increased to a maximum of 2:1 if fencing i� provided at or above the ma�imum water surface. • One foot of freeboard bet�v�en the top ��f�the rixer� and the cr�e�t c�1�tl�c emergenc� ;pil1��.3� . • Flat bottom. • Vlinimum 1-f�ot deep spillt�a`�. • Length-to-width ratio between 3:1 and 6 I • Sizing of Discliarge Mechanisms. The outlet for the basin consists of a combinat�on of princ�pal an� emerEency spillways. These outlets must pass the peak �tinofi�expec�c� from the contributing drainage area for a 100-year storni. If, due to site conditions and basin geometry, a separate emecgency spill-way is ne�t feasible, the principa) spillway must pass the entire peak runoff ezE�ectrd from the ]00-year storm. However, an attempt to provide a separate emergency spillway should always be made. The runoff calculation� shuuld be based on the site conditions during con�truction. The flo�� through the dewatering orifice cannot be utilized when calculating th� 100-year storm elevation because of its potentia] tu become clogged: therefore, available spillway storage must begin at the principal spill�,�a•, riser crest. The principal spillway designed by the procedures contained in thi� standard will result in some reduction in the peak rate of runoff. However, the riser outlet desian will not adequately control the ba�i�� discharge to the predevelopment discharge limitations as stated in Minimum Requirement#7: Flow Control. However, if the basin ti,r z� permanent stonnwater detention pond is used for a temporary sedimentation basin, the control structure for the permanent pond can be used to maintain predevelopment discharge limitations. The size ofi the basin, the expected life of the construction project, the anticipated downstream effects and the anticipated weather conditions duri�Ig construction, should be considered to determine the need c�f additi�nal discilarge�r�o� S�. �rT��f�- ri�ei- int�o�� cur��; FOR ASBUILT -- - ---- ----_ -- -__ 4-906 Volume!1— Construction Stormwater Pollution Prevenfron February 2005 Key diwder i�rto sbpe —�-��, to prevent flow a�W�Ni�t 4.2 Sediment iser il The pond length shall be 3 to 6 times the maximum pond width Emergency overfbw spillway , / 0 � Pon length �ur piv -- Inflow— Sifl tence or = Discharge to stabilized equivalent divider conveyance,outlet,or � level spreader � � Note:Pond may be fomied by bertn or by partial or oomplete excavation Figure 4.24-Sediment Pond Plan View Riser pipe (principal spillway) Crest of open at top with emergen spillway 6'min.Vvdth trash rack � ;-J I .�„w Embankment compacted 95% i I I—! � _--=-_= — i-111�� I Dewatering device � ,• _________� �pervious materials such as �� s (see riser detail) __ / gravel a clean sand shall 2 �= �-==---=----="_ I - � ______________ ''i notbeused � I ;� = r•=-______________ � � !r _ �-==-==-'========-==-�!" —i � � " - ----------- I •-----•-- `. ,s �i—I I, �-(��' E�� F=1� I I i � � n I � "�� 'I I=!I— —I C1':I E�� I I'� I I-I_!{- Discharge to stabilized �- Wire-backed silt fence p g w a t e r�n g C o n c r e t e b a s e conve yance o u t le t or staked hayba(es wrapped �fi� {see riser detail) level spreader with filter fabric,or equivalent divider Figure 4.25-Sediment Pond Cross Section Polyethylene cap Provide adequate sVapping Perforated polyethylene _ drainage tubing,diameter - Corrugated min.2"larger than = �*�etal nser dewatenng orifice. = Tubing shall comply = 3.5"min. with ASTM F667 and - Watertight pewatering orifice,schedule, AASHTO M294 - �� Tack weld 40 steel stub min. ' Diameteraspercakulations �'�;�� 6"min. r-__ �.�� __J 18'min. � Altematively,metal stakes ' � Concrete base and wire may be used to prevent flotation �---2X riser dia.Min.---I Figure 4. d r Detail FOR ASBUILT February 2005 Volume ll- Construction Stormwater Pollution Prevention 4-107 100 72 54 48 42 � 38 93 ) � 30 27 24 � 2� c � 18 n � o �� 15 � n , � � p 12 � 10 I � � I � 7 �� HEAD IN FEET (mee�u�red from erest of rlasr) �� Q,,.k=9.739 ON��a Qe��t�e.=3.782 D°H�n C In cfs, D and H In f�et Sfepa eh�ny• oceura •t w�lr-orific• transitlon Figure 4.27-Riser Inflow Curves NOT UPDATED FOR ASBUILT 4-108 Volume ll— Constructior� Stormwater Pollution Preven6on February 2005 Principal Spill�va��: Ueter7nine the reyuired diameter for th� princ�pa] spillv��ay (riser pipe). The diameter shall be the minimum necessary to pass the pre-developed l0-year peak flow (Q�o). Use Figure 428 to detennine this diameter{h = 1-foot). .�'ote: A perr�7anent control st,-ucrirrc ma}•be used i��stead of a temporary riser. Emergency Overflow Spillway: Deterniine the required size and design of the emergency overflow spillway for the developed 100-year peak flo��- using the method contained in Volu�ne III. Dewatering Orifice: Determine the size of the dewatering orifice(s j (minimum 1-inch diameter) using a modified version of the discharge equation for a vertical orifice and a basic equation for the area of a circular orifice. Determine the required area of the orifice with the following equation: A�(2{t}°�S .9„ _ 0.6x3600Tgp5 ��here Ao = orifice area (square feet) :9S = pond surface area {square feet} l� = head of water above orifice (height of riser in feet) T = der��atering time {24 hours) ,,� = acceleration of gravity (32.2 feet/second'`} Convert tlle required surface area to the required diameter p of the orifice: D = 24x��° = l 3.54x .40 � l�he vertical, perforated tubing connected to the dewatering orifice must be at least 2 inches larger in diameter than the �rifice to improve flow characteristics. The size and number of perforations in the tubing should be large enough so that the tubing does not restrict flow. The orifice �houid control the flow rate. • .Additional Design Specifications The pond shall be divided into two roughly equal volume cells by a pern�eable divider that will reduce turbulence while a(lowing movement of water between cells. The divider shall be at least one- half the height of the riser and a minimum of one foot below the top of t}�e riser. Wire-backed, 2- to 3-foot high, extra strength filter fabric �upported by treated 4"x4"s cat� be used as a divider. Alternatively, staked straw bales wrapped with filter fabric (geotextile) may be used. [f the pond is more than 6 feet deep, a different mechanism must be proposed. A riprap embankment is one acceptable method of se��aration ��eF�e ��i .��r designs that satisfy the intent of FOR ASBUILT February 2005 Volume !f- Construction Stormwater Pollution Preventron 4-909 this provision are allowed as long as the divider is penneable, structurally sound, and designed to prevent erosion tmder or around the barrier. To aid in determining sediment depth, one-foot intervals shall be prominently marked on the riser. If an embankment of more than 6 feet is proposed, the pond must comply with the criteria contained in Voh►me It1 regarding dam safety for detention B�V[Ps. • The most common structural failure of sedimentation basins is caused by piping. Piping refers to two phenomena: (I) water seeping through fine-grained soil, eroding the soil grain by b ain and forn�ing pipes or tunnels; and, (2) water under pressure flo�ving upward throt�gh a granular soil with a head of sufficient magnitude to cause soil grains to lose contact and capability for support. The most critical construction sequences to prevent piping ��ili be: 1. Tight connections between riser and barrel and other pipe connections. 2. Adequate anchoring of riser. 3. Proper soil compaction of the embankment and riser footing. 4. Proper constn�ction of anti-seep devices. :�fai�:le�rance • Sediment shall be removed from the pond when it reaches 1-foot in I Sta�rdards depth. • Any damage to the pond embankments or slopes shall be repaii-ed. NOT UPDATED FOR ASBUILT - - - - _- - -- - ---- --- - __ - 4-110 Votume 11— Construction StormV✓ater Pollutior P,�eveniron February 2005 BMP C233: Silt Fence Purpose Use of a silt fence reduces the transport of coarse sediment from a constniction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. See Figure 4.19 for details on silt fence construction. Conditions of Use Silt fence may be used downslope of all disturbed areas. ' • Silt fence is not intended to treat conccntrated flows, nor is it intended to treat substantial amounts of overland flow. Any concentrated flows must be conveyed through the drainage system to a sediment pond. The only circumstance in which overland flow can be treated sotely by a silt fence, rather than by a sediment pond, is when the area draining to the fence is one acre or less and flow rates are less than 0.5 cfs. • Silt fences should not be constructed in streams or used in V-shaped ditches. They are not an adequate method of silt control for anything , deeper than sheet or overland flow. Joints in filler fabric shall be spliced at posts. Use staples,wire rings or 2^x2"by 14 Ga. wire or equivalent to attach fabric to posts equivalent,ii standard___ --i-;�----- ,� -- strength fabric used -- � �� —� - � Fiiter fabric� I �' _ I � i I - I E � IN ! I , i � ' , � I ��; -�F� .=��"�ii--"'i'i -r-'-' =��i�i� -_ _��ii�i�li ii �i ._-i � �_�� =i�m-�r ��c ,,_ - ,, I �— 6'max --� � � Minimum 4"x4"trench �� +� � �� -� ' � f N �-� � �� Backfill trench with native soil�� - -�� Post spacing may be increased � or 3�4"-t.5"washed gravel � to 8'if wire backing is used � � 2"x2"wood posts,steel fence posts,or equivalent Figure 4.19—Silt Fence Design and • Drainage area of 1 acre or less or in combination with sediment basin I�:stallation in a larger site. Specifrcations • Maximum slope steepness (normal (perpendicular)to fence line) 1:1. • Maximum sheet or overland flow path length to the fence of 100 feet. • No flows greater than 0.5 cfs. • The geotextile used shall meet the following standards. All geotextile properties listed below are minimum average roll values (i.e., the test result for any sampled roll in a lot shall meet or exceed the values s1�o��i in T�`d1p�4T1�jI:PDATED FOR ASBUILT 4-94 Volume ll— Construction Stormwater Po!lufion Prevenfion February 2005 Table 4.10 Geotextile Standards _ __ __ - -- - - __--- _ _ __---- _ _ ---- -- -_ __----- Polymeric'�1esh AOS 0.60 mm maximum for slit tilm wovens(#30 sieve). 0.30 �', (.ASTh9 D4751) mm maximum for all other geotextile types(#So sieve). � 0.15 mm minimum for all fabric types{#100 sieve). i _ -- - — ---- ---- ---- - -- _ --- ------ -—_ _---- �i t��ater Permittitiity 0.02 sec"' minimum �; (ASTM D449]) �, : _ ------ -------------- ---- ------—__ _. ____ Grab Tensile Strength 180 lbs. Minimum for extra strength fabnc. ; f ASTM D4632) �! 100 lbs minimum for standard ctrength fabric. i ___ -- ------- --- _---_ _----- _ _ ------ __ _ j CiraU Tensile Strength 30%maximum ; (ASTM D4632) I�' - - -------_ _ ----- ---- — __- _ __- - - __-- _ ___ Ultraviolet Resistance 70°o minimum I', (ASTM D4355) ' i � • Standard strength fabrics shall be supported with wire mesh, chicken ��ire, 2-inch x 2-inch wire, saiety fence, or jute mesh to increase the strength of the fabric. Silt fence materials are available that have �ynthetic mesh backing attached. • Filter fabric material shall contain ultraviolet ray inhibitors and stabilizers to provide a minimum of six months of expected usable construction life at a temperature range of 0°F. to 120°F. • 100 percent biodegradable silt fence is available that is strong, long lasting, and can be left in place after the project is completed, if permitted by loca] regulations. • Standard Notes for constniction plans and specifications follo��. Refer to Figure 4.19 for standard silt fence details. The contractor sha11 install and maintain temporary silt fences at the locations shown in the Alans. The silt fences shall be constructed in the areas of clearing, grading, or drainage prior to starting those acti��ities. A silt fence shall not be considered temporary if the silt fence must function beyond the life of the contract. The silt fence shall prevent soil canied by runoff water from going beneath, through, or over the top of the silt fence, but shall allo�� the water to pass through the fence. The minimum height of the top of silt fence shall be 2 feet and the maximum height shall be ?'ii feet above the original bround surface. The geotextile shall be sz��m together at the point of manufacture, or at an approved location as detern�ined by the Engineer, to forn� geotextile lengths as required. All sewn seams shall be located at a support post. Alternatively, two sections of silt fence can be overlapped, provided the Conh�actor can demonstrate, to the satisfaction of the Engineer, that the overlap is long enough and that the adjacent fence sections are close enou�h to�ether to prevent silt laden ��-ater from escapitlg through t}�I��e��i� FOR ASBUILT February 2005 Volume ll- Construction Stormwater Poilution Prevention 4-95 The geotextile shall be attached o�i the up-slope side ofthe post� ancl support system with staples, wire, or in accordance with the manufacturer's recommendations. The geotextile shall be attachcd tu the posts in a manner that reduces the potential for geotextile tearing at the staples, wire, or other connection device. Silt fence back-up support for the geotextile in the form of a wire or plastic mesh is dependent on the properties of the geotextile selected for use. If wire or plastic back-up mesh is used, the mesh shall be fastened securely to the up-slope of the posts with the geotextile being up-slope of the mesh back-up support. The geotextile at the bottom of the fence shall be buried in a trench to a minimum depth of 4 inches below the ground surface. The trench shall be backfilled and the soil tampzd in place over the buried portion of the geotextile, such that no flow can pass beneath the fence and scouring can not occur. When wire or polymeric back-up support mesh is used, the ��ire or pol}�meric mesh shall extend into the trench a minimum of 3 inches. The fence posts shall be placed or driven a minimum of 18 inches. A minimum depth of 12 inches is allowed if topsoil or other soft �ubgrade soil is not present and a minimum depth of 18 inches cannot he reached. Fence post depths shall be increased by 6 inches if the � fence is located on slopes of 3:1 or steeper and the slope is peipendicular to the fence. If required post depths cannot be obtained, t}�e posts shall be adequately secured by bracing or guying to prevent ��erturning of the fence due to sediment loading. Silt fences shall be located on contour as much as possible, except at the ends of the fence, where the fence shall be turned uphill such that the silt fence captures the runoff water and prevents water from 1luwing around the end of the fence. If the fence must cross contours, with the exception of the ends of the i�ence, gravel cl�eck dams placed perpendicular to the back of the fence shall be used to minimize concentrated flow and erosion along the back of the fence. The gravel check dams shall be approximately 1- foot deep at the back of the fence. It shall be continued petpendicular to tlie fence at the same elevation until tlle top of the check dam intercepts the ground surface behind the fence. The gravel check dams >l�all consist of crushed surfacing base course, gravel backfill for ��alls, or shoulder ballast. The gravel check dams shall be located e�ery 10 feet along the fence where the fence must cross contours. The slope of the fence line where contours must be crossed shall not he steeper than 3:1. �Vood, steel or equivalent posts shall be used. Wood posts shall have minimum dimensions of 2 inches by 2 inches by 3 feet minimum lcn�th, and��e f�� c��f�s�s such as knots, splits, or gouges. FOR ASBUILT _ -- --- ---- _ ___ -- -- 4-96 Volume Il- Construction Stormwater Pollutron Preventron February 2005 i Steel posts shall consist of either size No. 6 rebar or larger, ASTM A 120 steel pipe with a minimum diameter of ]-i�ich, U, T. L, or C shape steel posts with a minimum weight of 1.35 lbs.%ft. or other stee] posts having equivalent strength and bending resistance to the post sizes listed. The spacing of the support posts shall be a maximum of 6 feet. Fence back-up support, if used, shall consist of steel wire with a maximum mesh spacing of 2 inches, or a prefabricated polymeric mesh. The strength of the wire or polymeric mesh shall be equivalent to or greater than I 80 ibs. grab tensile strengtli. The polymeric mesh must be as resistant to ultraviolet radiation as the geotextile it supports. � Silt fence installation using the slicing method specification details follow. Refer to Figure 4.20 for slicing method details. The base of both end posts must be at least 2 to 4 inches above tl�e top of the silt fence fabric on the middle posts for ditch checks to drain properly. Use a hand level or string level, if necessary, to mark base points before installation. install posts 3 to 4 feet apart in critical rete�ition areas and 6 to 7 feet apart in standard applications. Install posts 24 inches deep on the downstream side of the silt fence, and as close as possible to the fabric, enabling posts to support the fabric from upstream water pressure. install posts with the nipples facing away from the silt fence fabric. ' Attach the fabric to each post with three ties, all spaced within the top 8 inches of the fabric. Attach each tie dia�onally 45 degrees through the fabric, ��ith each puncture at least 1 inch vertically apart. In addition, each tie should be positioned to hang on a post nipple when ' tightening to prevent sagging. ��rap approximately 6 inches of fabric around the end posts and secure , ��-ith 3 ties. ' l�o more than 24 inches of a 36-inch fabric is allowed above ground level. "Che rope lock system must be used iii all ditch check applications. The installation should be checked and corrected for any deviation before compaction. Use a flat-bladed sllovel to tuck fabric deeper into the ground if necessary. Compaction is vitally important for effecti��e resultc. Compact the soil immediately next to the silt fence fabric with the front wheel of the tractor, skid steer, or roller exerting at least 60 pounds per square inch. Compact the upstream side first and then each side twice for a total of four trips. NOT UPDATED FOR ASBUILT February 2005 Volume 1!- Ccnstruct,on Stormwater Pollutron Prevention 4-97 • Any dan�age shall bc repaired inl►nediately. ,'L�uinte�rattce If concentrated flows are evident uphill of the fence, they must bc SlllltllUl'lI.0 • intercepted and conveyed to a sediment pond. • It is imporiant to check the uphill side of the fence for signs of the fence clogging and acting as a barrier to flow and then causing channelization of flows parallel to the fence. If this oecurs, replace the fence or remove the trapped sediment. • Sediment deposits shall either be removed ��hen the deposit reaches � approximately one-third the height of the silt fence, oc- a serond silt fence shall be installed. ' • If the filter fabric (geotextile} has deteriorated due to ultraviolet breakdown, it shall be re ]aced. ►onoq h.i�A� r03T i�AtING: II iw�r.=i' T w��r.�w p�n nw�• �� . ...--•----._.. .. ._.---•-�--•-•TaP o!Febtc TT �w1aIL�I�PMIM�Y�i! � ��, AlfaC�IfYI1C 10 �� i �ys4��IM A�«! '�.. �8• FLOr1—� wtw�wr ac�ws N r ►OiT DF►TH: •N bwcs 2�s t O�N� N�h M��ey�/ .Nu�.�+e•.are.� r, �s h�ele�Mw pwna eo P..�.«�...e.r r r r Oietpnel snacnr.�nt �tOD'f�c�wM�tl�/' �oO%crMscNw ooutlassor`4� �� /i /�/� `// /�/ /��j � ft T('-��:; �� \��\ �� _ �:1:� [ C. ��,�\%�!�{ ��i/�j�;/�� '�=i?�.c".fE�..: /' ��\\�� /\� \� \� \� A7TACIMEM Ot7ARS: /��\�\/�� /, /// //,/// //�/j// � /��\\�j\\/�� C,�n�tabA��t pars,��wA�a. /��/��j% / ��/��/�%,�\ •tAitae wss nsa psr pait a�v�Rern�op s•m he�. / / / /� \\�� \��\�\�� •N�/uon Nd�w A�ponNy�pw�cwitrg hws vstkay �/�\��/ � \�/��\�� a mYi+vn d 1'apeit. 1 � \ \� � No moro than 24'of a 36'fabric �u��.n.�poia�Q.a�� is ellowed ebovs yround. Ro0 of sR fence �� OPpratlon Paet nftale�d aR6t compaC6on f�CAc �°bOV° $R FenGe 9�+d a`.� �—,a�- '�+ ,y a �.:�` .4F�%' ..V.\�\��i? .*G'��y� . �'��./� �r i i�ii..��i�i � ��.�.��! 1p' .�>t''��J�`i��p n '.��/O�� -%\�i::. �F ��i��t�Fbai�, �\� 20Q30Unim ' �y�� . % �% ��.' �!'�� y� � �- ��y��ii��'�\��4v�� `�� h,o!.�,. ,��'� Q � �� .� .. �`c ' i. 110fltontd Clbd P�K Skhg hiDdC f76 mm+Mdlf� (18 mmwldll� Com0leted Muralatlon Vibratory pbw is na accepteble becauae of tar�nntel compaction Figure 4.2 - ' F ' n by Slicing Method FOR ASBUILT 4-98 Volume ll— Co��struction Stormavater Pol/ufion Prevention February 2005 BMP C120: Temporary and Permanent Seeding Pinnose Seeding is intended to reduce erosion by stabilizing exposed soils. A well-established ��egetative cover is one of the most effective methods of reducing erosion. Co�:ditions of L'se ' Seeding may be t�sed throughout the project on disttirbed area� that have reached final grade or that ��ill remam un��orked ror mure than 30 days. • Channels tllat will be ��egetat�d shoul�i be iilstalled befure maj��r- earthwork and hvdroseeded with a Bonded Fiber Matrix. The vegetation should be u�ell established (i.e., 75 percent cover) befo�e water is allowed to flow in the ditch. With channels that will ha��e high flows, erosion control blankets should be installed over the l�ydroseed. If vegetation cannot be established from seed before ��at�r is allowed in the ditch, sod should be installed in the bottom of th� ditch over hydromulch and blankets. • Retention!detention ponds should be seeded as requircd. • Mulch is required at all times because it ��r��tect� secd� `:rom hc<it, moish�re loss, and transport due to runof�i • All disturbed areas shall be reviewed in late :�uLust to c��rly Sc��tcmh�r and all seeding should be completed by the end of Septembcr Othervvise, vegetation �vill not establish itself enou�h to pro�, �dc mc�r� than average protectioi�. • At final site stabili�ation, all disturbed areas i�ot other��se �e�ctatcd ur stabilized shall be seeded and nuilched. Final stabilization n�ean� thc completion of all soil disturbing activities at the site and the establishment of a pennanent vegetative cover, or equivalent permanent stabilization measures (such as paveinent, riprap. �ahi;,;>> or geotextiles) which ��ill prevent erosion. Design n»d • Seedi�ig should be done durina those seasons most conduci�� t�� Ir�stallutinn growth and will vary with the climate conditions of the re_��>> Specifications Local experience should be used to determine the appropria�: seeding periods. • The optimum seeding windows for��estern Washington are Apr�l 1 throu�h June 30 and September 1 through October 1. Seeding that occurs between July 1 and August 30 will require ii-rigation until �� percent jrass cover is established. Seeding that occurs between October 1 and March 30 will require a mulch or plastic cover until ?5 percent grass cover is established. • T� pr•event seed fi-om being washed away, confinn that all require�l surface water control measures have been installed. NOT UPDATED FOR ASBUILT February 2005 Volume !1- Constructron Stcrmwater Pollutier Prevention 4-93 • The seedbed should be firm and rough. All soil should be roughened no matter what the slope. If compaction is required for engineering purposes, slopes must be track walked before seeding. Backblading or smoothing of slopes greater than 4:1 is not allowed if they are to be seeded. • New and more effective restoration-based landscape practices rely on deeper incorporation than that provided by a simple single-pass rototilling treatment. Wherever practical the subgrade should be initially ripped to improve long-ternl permeability, infiltration, and water inflow qua]ities. At a minimum, permanent areas shall use soil amendments to achieve organic matter and permeability performance defined in engineered soiUlandscape systems. For systems that are deeper than 8 inches the rototilling process should be done in multiple lifts, or the prepared soil system shall be prepared properly and then placed to achieve the specified depth. • Organic matter is the most appropriate form of"fertilizer" because it provides nutrients (including nitrogen, phosphorus, and potassium) in the least water-soluble form. A natural system typically releases �-10 percent of its nutrients annually. Chemicai fertilizers have since been forn�ulated to simulate what organic matter does naturally. • In general, 10-4-6 N-P-K (nitrogen-phosphonis-potassium) fertilizer can be used at a rate of 90 pounds per acre. Slow-release fertilizers should always be used because they are mo1-e efficieilt and have fewer �nvironmental impacts. It is recommended that areas being seeded for final landscaping conduct soii tests to detern�ine the exact type and c�uantity of fertilizer needed. This will prevent the over-application of tertilizer. Fertilizer should not be added to the hydromulch machine and agitated more than 20 minutes before it is to be used. If agitated too much, the slow-release coating is destroyed. • There are numerous products available on the market that take the E,lace of chemical fertilizers. These include several with seaweed extracts that arz beneficial to soil microbes and organisms. If l OQ percent cottonseed meal is used as the mulch in hydroseed, chemical fertilizer may not be necessary. Cottonseed meal is a good source of I��ng-tenn, slow-release, available nitrogen. • Hydroseed applications shall include a minimum uf 1,�00 pounds per acre of mulch with 3 pei•cent tackifier. Mulch may be made up of 100 percent: cottonseed meal; fibers made of wood, recycled cellulose, hemp, and kenaf; compost; or blends of these. Tackifier shall be plant- hased, such as guar or alpha plantago, or chemical-based such as polyacrylamide or polymers. Any mulch or tackifier product used shall be installed per manufacnuer's instructions. Generally, mulches come in 40-50 pound bags. Seed and fertilizer are added at time of a��p�ication{�OT UPDATED FOR ASBUILT 4-14 Volume !!- Construcfion Storm�vater Pollution PrevenUcn February 2005 • 1�Iulch is always required for seeding. I�4ulch can be applied on top of the seed or simultaneously by hydroseeding. • On steep slopes, Bonded Fiber Matrix (BFM1 or Mechanically Bonded t=iber Matrix (MBFM) products should be used. BFM!MBFUI products are applied at a minimum rate of 3,000 pounds per acre of mulch with approximately 10 percent tackifier. Application is made so that a minimum of 95 percent soil coverage is achieved. Numerous products are available commercially and should be installed per ►nanufacturer's instructions. Most products require 24-3( hours to cure before a rainfall and cannot be installed on wet or saturated soils. Generally, these products come in 40-50 pound bags and include all ►lecessary ingredients except for seed and fertilizer. BFMs and MBFMs have sume advantages over blankets: • No surface preparation required; • Can be installed via helicopter in remote areas; • On slopes steeper than 2.5:1, blanket installers may need to be roped and harnessed for safety; • They are at least $1,000 per acre cheaper installed. In rnost cases, the shear strength of blankets is not a factor when used on �lopes, �nly when used in channels. BFMs and MBFMs are good alternatives ro blankets in most situations where vegetation establishment is the goal. . • �'Vhen installing seed via hydroseeding operations. only about li3 of the seed actually ends up in contact with the soil surface. This reduces tl�e ab�lity to establish a good stand of grass quickly. One way to overcome this is to increase seed c3uantities by up to 40 percent. • Vegetation establishment can also be enhanced by dividing the hydromulch operation into two phases: 1. Phase 1- Install all seed and fertilizer��ith 25-30 percent mulch and tackifier onto soil in the first lift; 2. Phase 2- lnstall the rest of the mulch and tackitier over the first lift. An alten�ati�-e is to install the nnilch. seed, fertilizer, and tackifier in one lift. Then, spread ar blow straw o��er the top of the hydromulch at a rate ot� about 800-1000 pounds per acre. Hold straw in place with a ctandard tackifier. Both of these approaclles will increase cost moderately but will greatly improve and enhance vegetative estahlishm�nt. The inci�eased ce�st may be offset by the reduced need for-: l. Irc-igati�n 2. Reapplication of mulch 3. Repai�a�ilcc�c �i�r.��a� FOR ASBUILT February 2005 Volume ll— Constructron Stormv✓ater Pollution Preventron 4-45 l�hi� tecl�n��ue «ork� ��ith �tandard hyciromulch ( 1.�U(1 p��und: per ��cr� minintum) and BFMIMBFMs (3,000 pounds per acr� niinimum). • Areas to be permanently landscaped shalf pro�ide a healtl�y top,��il that reduces the need for fertilizers, improves overall topsoil quality. provides for better vegetal health and vitality, improves hydrologic characteristics, and reduces the need for imgation. This can be accomplished in a nutnber of ways: Recent research has shov��n that the best method to improve till ;��ils i� to amend these soils with compost. The optimum mixture is approximately two parts soil to one part compost. This equatc� t�� -i inches of compost mixed to a depth of 12 inches in till soils. Increa�iu`� the concentration of compo5t beyond this level can have negati�e effects on vegetal health, while decreasing the concentrations can reduce the benefits of amended soils. Please note: The compost �hc,uld meet specifications for Grade A qualiry compost in Ecolog}� Publication 94-03R. Other soils, such a� �r:��cl or cobble out��ash soilt. mav re�iuire different approaches. Organics and t7nes easily migrate throt�gh t}�e loose stnicture of these soils. Therefore, the importation of at least 6 inches of qualitv topsoil, underlain by some type of tilter fabric to prevent the migratio�i of fines, may be mare appropriate for these soils. Areas that already have good toj��c�il. �t�ch ��s uncli;tu��bed ��re��. �iu n��t require soil amendmei�ts. • Areas that will be seeded only and not landscaped may need rt�i»p��t or meal-based mulch included in the hydroseed in order to etitablish vegetation. Native topsoil should be re-installed on the disturbed soil surface before application. • Seed that is installed as a temporary measure may be installed by hand if it will be covered by straw, mulch, or topsoil. Seed that is installed as a permanent mea.sure may be installed by hand on small areas (usually less than 1 acre) that will be covered with mulch, topsoil, e,r erosion blankets. The seed mixes listed belaw include recommended mixes for both temporary and permanent seeding. These mixes, with the exception of the ��etland mix, shall be applied at a rate of 120 pounds per acre. This rate can be reduced if soil amendments or slow- release fertilizers are used. Local suppliers or the local conservation district should be consulted for their recommendations because the appropriate mix depends on a variety of factors, including location, exposure, soil type, slope, and expected foot traffic. Alternative seed mixes approved by the local autl�ority may be used. NOT UPDATED FOR ASBUILT 4-16 Volume !!— Consfrucfion Stormwater Pollutron Prevention February 2005 � Table 4.1 represents the standard mix t�or those areas ��he.re just a temporary ve�etative cover is required. Table 4.1 Tem ora Erosion Control Seed Mix '' % V1;ei ht % Purit�- %Gcrmination ' Che��ings or annual blue grass 40 98 90 ;i Fesh�ca rubru rar. commulata or Pan anna —- —----- ----__---- -_ ----- -------- ------ - -- i _ -- ._ Perennial rye- 50 98 90 ; Lolium per•enne_ __- � Redtop or colonial bentgrass -- - ---------- 5— - 92 --- - -RS _ _�rostis alba or Agrostis tenuis ' __ --------- ---__ - --- -- White dutch clover 5 98 90 ' Ti-ifolrum�•e ens __ �', ?able 4.2 provides just one recommended possibility for landscaping seed. Table 4.2 ! Landsca in Seed Mix � "/o�Yei ht "o Purit� %Germinatiun ' Perennial rve blend 7Q 98 90 ' Lolicrn��renne -_ --__ ! -- - ---- ._- -- -- - _------_ _ __ I'' Chewings and red fescue blend 30 9R 90 � ' Festuca n�h��a rar. comnairtnta � ' or Festrrca rubra This turf seed mix in Table 4.3 is for drv situations where there is nc� nec� for much water. �Thr ad��ants��c i� that thi� mix rcyti�rts �er� littic maintenance Table 4.3 � Low-Growin Turf Seed Mix % Wei ht "/�Purit�• %Germination � Dwarf tall fescue(several varieties) 45 98 90 Feslrrca nrunc�i�lacea i•ar. ' ------_ __--- ---__ ____ _ __ _--_ _- ------- _--- ____ ___ . Dwarf perennial rye(Barclay) 30 98 90 Loliuntpercrnc var. harclav ' _ ------ - -----K-- - —- --_ ___ __ __ Red fescue 20 9R 90 + Festucci rubrn ----------- --- - __ ___ _— - ---- _ __ Culonial bentgras� � 9� 90 � .� 1•nstis tertiris _� Table 4.4 presents a mi� rec��i��mend�d t��r l�ic��alr, and ��thcr intermittently wet area�. Table 4.4 �I Bioswale Seed Mix' %�i'ei�ht "/o Purih %Germination rall ur meado�� fescue 75-80 9�S 90 , Feshica arundrnacea or Festuca elatia� � --- __ _ _ - __-------- --_-_ -- _ __ _ _- - 5easidc'Creepine bentgrass 10-15 92 g5 --- •qg•rostis palirstrrc_ ' - -- -_ __---- -- ----- --- -- - � Redtop bentgrass 5-10 90 80 A !•ostis ulba or flqrostis 1 antea ;� * ,�loclilied Brinrar e�t Irac. Hl�rfroseedrri<� Gr�ide t4�c°tln�re��S�ec�".1r: I��rt UPDATE� FOR ASBUILT February 2005 Volume 11- Construction Stormwafer Pollution Prevention 4-17 The seed mix shown in Table 4.5 is a recommended low-gro��-ing, relatively non-invasive seed mix appropriate for very wet areas that are nat regulated wetlands. Other mixes may be appropriate, depending on the soil type and hydrology of the area. Recent research suggests that bentgrass (agrostis sp.) should be emphasized in wet-area seed mixes. ' Apply this mixture at a rate of 60 pounds per acre. Table 4.5 ' Wet Area Seed Mix* %V1'ei ht % Purih %Germination Tall or meadow fescue 60-70 98 90 ' Festuca a�-��ndirtacea or Fesheca elatror - -------- - -- _-- --------- _ _ __-- - -- -- ---- __---- Seaside/Creeping bentgrass 10-15 98 85 _ A rustis pulustris ---__ __ _ _ __ _ --- _ _---- - --- _ Meadow foxtail 10-15 90 80 _ Alepoca.n�u.c�rate�rsis ----- --- ---_--- _ _- --- ------- - -- __ Alsike clover 1-6 98 90 Ti•i�ol iuni_hybrt d:mr - -- ____ _ �_- - - ------- ---------- - Redtop bzntgrass 1-6 92 85 A r�osris alha * !llndified Brial�reE°n, l�rc•. H}-clroreedi�Tg Gui��c� N�etlu,�ds See�f.'��ix ' The meadow seed mix in Table 4.b is recommended for areas that will be maintained infrequently or not at all and ��here colonization by native plants is desirable. Likely applications include rural road and utility right- ' of-way. Seeding should take place in September or very early October in order to obtain adequate establishment prior to tlle ��inter months. The appropriateness of clover in the mix �nay need to be considered, as this can be a fairly invasive species. If the soil is amended, the addition of clover may not be necessary. Table 4.6 Meadow Seed Mix %V1ei ht °o Purih %Germination Redtop or Oregon bentgrass �0 92 85 A�r-n.r�is alba or Agrostis ore�oner�sis_ _ i - - --_ _— --_ _ Red fescue 70 98 90 Festucu ruhra ---------- —----- _____ -- White dutch clover 10 98 90 Tr•iJoliuni re ens Mainte�la�ree • Any seeded areas that fail to establish at least 80 percent cover(100 Sta�rdards percent cover for areas that receive sheet or concentrated flows} shall be reseeded. If reseeding is ineffective, an alternate method, such as sodding, mtilching, or nets�blankets, shall be used. If winter weather prevents adequate grass growth, this time limit may be relaxed at the discretion of the local authoritv w•hen sensitive areas would otherwise be protected. NOT UPDATED FOR ASBUILT 4-98 Volume ll- Construction Stormwater Pollution Preverrtion February 2005 • After adequate cover is achie��ed, any areas that experience erosion shall be reseeded and protected b}� mulch. If the erosion problem is drainage related, the problem shall be fixed and the eroded area reseeded and protected by mulch. • Seeded areas shall be supplied with adequate moisture, but not watered to the extent that it causes runoff. � ,,- ; � � ,-i , ; NOT UPDATED FOR ASBUILT February 2005 Volume !1— Construction Stormwater Pollution Prevention 4-19 BMP C122: Nets and Blankets Pr�rpose Erosion control nets and blankets are intended to prevent erosion and hold seed and mulch in place on steep slopes and in channels so that ve�etation can become well established. In addition, some nets and blankets can be used to permanently reinforce turf to protect drainage ways during high flows. Nets (commonly called matting) are strands of material woven into an open, but high-tensile strength net (for example, coconut fiber matting). Blankets are strands of material that are not tightly woven, but instead form a layer of interlocking fibers, typically held together by a biodegradable or photodegradable �Zetting (for example, excelsior or stra�� blankets). They generally have lower tensile strength than nets, but cover the ground more completely. Coir (coconut �ber) fabric comes as both nets and blankets. Conditions of L'se Erosion control nets and blankets should be used: • To aid pernlanent vegetated stabilization of slopes 2H:1 V or greater and with more than 10 feet of vertical relief. • For drainage ditches and swales (highly recommended). The applicatian of appropriate netting or blanket to drainage ditches and s«�ales can protect bare soil from channelized runoff while vegetation i� established. Nets and blankets a(so can capture a great deal of i sediment due to their open, porous structttre. Synthetic nets and ' blankets can be used to pernlanently stabilize channels and may provide a cost-effective, environmentally preferable alternative to riprap. l 00 percent synthetic blankets manufactured for use in ditches may be easily reused as temporary ditch liners. I)isadvantages of blankets include: • Surface preparation required; • O�i slopes steeper than 2.5:1, blanket installers may need to be roped and harnessed for safety; • They cost at least $4,OU0-6,000 per acre installed. .�dvantages of blankets include: • Can be installed without mobilizing special equipment; • Can be installed by anyone with minimal training; • Can be installed in stages or phases as the project progresses; • Seed and fertilizer can be hand-placed by the installers as they progress down the slope; • Can be installed in any weather; • There are numerous types of blankets that can be designed with various parameters in mind. Those parameters include: fiber blend, i��csh stren��,�Tg�-�}��lability, cost, and availability. FOR ASBUILT - ._-- ----- _ - - - - -- 4-22 Volume ll— Construction Storrnwater PoNution Prevention February 2005 Design and • See Figure 4.4 and Figure 4.5 for typical orientation and installation of Installution blankets used in channels and as s]ope protection. Note: these are Specifications typical only; all blankets must be installed per manufacturer's installation instructions. • Installation is critical to the effectiveness of these products. If good grot►nd contact is not achieved, runoff can concentrate under the product, resulting in significant erosion. • Installation of Blankets on Slopes: 1. Complete final grade and track �valk up and down the slope. 2. Install hydromulch with seed and fertilizer. 3. Dig a smal] trench, approximately 12 inches wide by 6 inches deep alo�lg the top of the slope. 4. lnstall the leading edge of the blanket into the small trench and staple approximately every 18 inches. NOTE: Staples are metal,"U"-shaped, and a minimum of 6 inches long. Langer � staples are u�ed in s.ind�� oils. Biod��radable stakes ar� al�o availabie. 5. Roll the bianket slo��ly do��n the slope a� �nstall�r ��alk� backwards. NOTE: The blanket rests against the instailrr�. le�� Staples are installed as the blanket is unrolled. It is critical ihai �1�� proper staple pattern is used for the blanket being installed. Tl�e blanket is not to be allowed to roll down the slope on its o�m a� this stretches the blanket making it impossible to maintain soil contact. ln addition, no one is allowed to walk on the blanket ��i��cr it is in place. 6. If tl�e blanket is not long enough to cover the entire slope length. the trailing edge of the upper blanket should overlap the ]eadin�� edge of the lo��er blanket and be stapled. On steeper �lo}�cs. thi� overlap should be installed in a small trench, stapled. �ncl c:c»�red with soil. • With the variety ofproducts available, it is imposs�ble to cover all thc details of appropriate use and installation. Therefore, it is critical that the design engineer consults the manufacturer's information and that :1 site visit takes �lace in order to insure that the product specified is appropriate. Infarmation is also available at the following ��ch site� 1. WSDOT: http:!!www.wsdot.wa.gov�'eesc/environmental` 2. Texas Transportation Institute: l�tt�':��w��v.d��t_,state.tx.us`insdtd�t��r..�hart-cmd!crosion�'contents. „- htrn _____ _ NOT UPDATED FOR ASBUILT ---- -- - --- ----- ----- - February 2005 Volume ll- Cei�sfruction Stormwater Pol��rtror Preve�;tron 4-23 • Jute mattin� must be used in conjunction with mulch (BMP C121). Excelsior, wo�.�en straw blankets and coir (coconut fiber) blankets may be installed without mulch. There are many other types of erosion control nets and blankets on the market that may be appropriate in certain circumstances. • In general, most nets (e.g.,jute matting) require mulch in order to prevent erosion because they have a fairly open strucnire. Blankets typically do not require mulch because they usually provide complete protection of the surface. • Extremely steep, unstable, wet, or rocky slopes are often appropriate I, candidates for use of synthetic blankets, as are riverbanks, beaches and '' other high-energy environments. If synthetic blankets are used, the I soil should be hydromulched first. I • l00 percent biodegradable blankets are available for use in sensitive il areas. These organic blankets are usually held together with a paper or fiber mesh and stitching which may last up to a year. • �9ost netting used with blankets is pllotodegradable, meaning they break down under sunlight (not UV stabilized). However, this process can take months or years even under bright sun. Once vegetation is established, sunlight does not reach the mesh. It is not uncommon to find non-degraded netting still in place se�eral years after installation. "I�his can be a problem if maintenance requires the use of mowers or ditch cleaning equipment. In addition, birds and small animals can become trapped in the netting. ,tJai�rtena�ree • Vood contact with the ground must be maintained, and erosion nuist S�rrrrdurds not occur beneath the net or blanket. • :1ny areas of the net or blanket that are damaged or not in close contact ��ith the ground shall be repaired and stapled. • If erosion occurs due to poorly controlled drainage, the problem shall he tixe.d and the eroded area protected. NOT UPDATED FOR ASBUILT 4-24 Volume ll- Construcfion Stormwater Pollution Prevention February 2005 ' i � __ �_..__ ` �..._.__ ___— J. y� �// \ / � � R % 1 a . � I �`� /�/��/ � �'� . P i �,/ij��/j �/�/��/j�/ ,\�� :�°.• j�/��%�.: ,�,,. �\ `�. /\�j� ,\\ �\ \� \ �\, � \\ ��j\\/\�� .6.��I\�\�� .\�j� , ��,//•%/. �%/� �� . �-,\/�` 1150mm1��/��/�.- � vf'6 tt50mm) \ Longituo nal Anchor Trench TeRninal Slope and Channel Anchor Trench � * � � �� Y i 1�= � Y � �, G' Y � � Y Stake at 3'-5' \ � � ft-t.5m)intervals. ��'� � _, — � Y � 'r. �"\ � —.'''�`� .(f� �,(`.. -_�" � � *ai � � " �.' _c�,� / � Y �%� l . /�,� �b�, V'� G_,/ � �� G �._ �� \ � .. /�\�� \j\/\%�%� >r�a•- � ��%�/��/�,: �� //�/ ��\-.,-'�Check slot at 25'(7_6m)intevals �' � �%/\\�%�\� Isometric View ��i��ii��!i �,�� ' � �� 6'1i50�nn� � � � j\/�/�, ' p� , u,•.. ��\//\ ., . �/� 'i' �� i � ��' � • �. r.ma+�,\ . \j�\��\ •'•o ,��\/�� 1`�/��i�� 1 �,�'�y i}�' /��\��\'� `c\\\\�\\�\\\\\ \�� \\�%. �\ (tsomml �/\\�\\\�%� InRial Channel Anchor Trench Intermitlen[Check Sbt NOTES: L Cixck slots ro be construqed per manutacturers specifications. I . 2.S�aking or shpiing layout per manufatturcrs specifiabons. , Figure 4.4—Channel Instailation I Slope surface shall be smooth before I placement for proper soil contact. If there is a berm at the Stapling pattem as per top of slope,anchor manufacturer's recommendations. �� - upslope of the berm. � � .y._ Min.2" � �. ::.-. ... � Overiap � � � � � I�� Anchor in 6"x6"min-Trench � i ,,� and staple at 12" intervals. � �_ � � �• Min.6"overlap. _ ` � (��. "�I If�— • =_'.�_- ..,. , � _ _ ��,,�I I—��=L�TiL��i i i��T� max I 5�sPac'Ing. Bring matenal down to a level area,tum Do not stretch blankets/mattings tight- Me end under 4'and staple at 12'intervals albw the ro�ls to mold to any irregularities. For slopes less than 3H 1V,rolls Lime,fertilize,and seed before ir�stallatio�. may be placed in Fwrizontal strips. Pianting of shrubs,Uees,etc.Should occur after installation. Fi�11�Ts��+(�}�on ' FOR ASBUILT February 2005 Volume 1!— Consfruction Stormwater Pollution Prevention 4-25 BMP C123: Plastic Covering Pt�rpose Plastic co��ering pro��ide� immediate, short-term erosion protectic�n to slopes and disturbed areas. Conditions of • Plastic covering may be used on disturbed areas that require co�•er Use measures for less than 30 days, except as stated below. • Plastic is particularly useful for protecting cut and fill slopes anci stockpiles. Note: The relatively rapid breakdown of most polyeth� l�•n: sheeting makes it unsuitable for lon��-tenii (greater than six ni��nth�) applications. • Clear plastic sheeting can be u;ed o��er ne��ly-s�eded areas t�� creat� a greenhouse effect and encourage grass growth if the hydroseed was installed too late in the season to establish 75 percent grass cover, c>r i f the wet season started earlier than norn�aL Clear plastic should not be used for this purpose during the summer months because the resultin� high temperatures can kill the grass. • Due to rapid runoff caused by plastic sheeting, this methi�d �I�,li! n��t h� used upslope of areas that might be adversely impacted h� concentrated runoff. Such areas include steep and/or un�t<ii�l� �lo��e;. • While plastic is inexpensive to purchase, the added cost of installat��,��. maintenance, removal, and disp��al mak� tlll� ��n ,xpcnsi�e ��ateriai. up to $1.50-2.00 per square yarc�. • Whenever plastic is used to protcct slu��e;, ��ater coll�ction mca�urr: must be installed at the base of the slope. These measures include plastic-covered berms, channels, and pipes used to covey clean rainwater away from bare soil and disturbed areas. At no time is cle�lil runoff from a plastic covered slope to be mixed w�ith dirty runoff fro�ii a project. • Other uses for plastic inclu�le: 1. Temporary ditch liner: 2. Pond liner in temporary sediment pond: 3. Liner for bermed temporary fuel stora�� ar�a it}�la>tic is n��t reactive to the type of fuel being store�j: 4. Emergency slope protection during hea�� rain�: ailcj. 5. Temporary drainpipe ("elephant tnink") used to direct w atcr. NOT UPDATED FOR ASBUILT 4-26 Volume ll— Construction Stormwater Pollution Prevention February 2005 Design und • Plastic slope cover must be installed as follows: Installation �. Run plastic up and down slope, not across slope; Specifrcations 2. Plastic may be installed perpendicular to a slope if the slope length is less than 10 feet; 3. Minimum of 8-inch overiap at seams; 4. On long or wide slopes, or slopes subject to wind, all seams should be taped; 5. Place plastic into a small (12-inch wide by 6-inch deep} slot trench at the top of the slope and backfill with soil to keep water from tlowing underneath; 6. Place sand filled burlap or geotextile bags every 3 to 6 feet along seams and �ound a �voc�den stake throu�h e�ich to hold them in � place: 7. Inspect pla,tic 1or riE,;. t�arc. and oE��n ��am� re��ularlti� and reE�air immediately. This prevents high velocity r�u�oi�f from contacnn�� bare soil which causes extreme erosion; 8. Sandbags may be low�ered into ��lac� tied to r��; H��c��r. all sandbags must be staked in plac�. • Plastic sheeting shall have a minimum thickness of 0.06 millinleter�. • If erosion at the toe of a slope is likely, a gravel berm, riprap, or otf�� suitable protection shall be � ' ' reduce the velocity of runo± ��ai��te�tu»ce • Torn sheets must be replac��. .,,,., , � ,.,. ,,.,�,, ;,,;.,,:. Sta�rdards • If the plastic begins to deteriorate due to ultraviolet r.. be completely removed and replaced. • �Vhen the plastic is no longer needed, it shall be completel� remo�eci. • nispose ��t old tires a��}�ropriately. NOT UPDATED FOR ASBUILT -- - __ - - --- - - ---- -- February 2005 Volume !l- Ccnstructron Storr�water Polli�t�on P��e��ertror� 4 27 BMP C125: Topsoiling Pu�puse To provide a suitable growth medium for final site stabilization with vegetation. VVhi1e not a pern�a�lent cover practice in itself, topsoiling is an integral component of providing pern�anent cover in those areas where there is an unsuitable soil surface for plant growth. Native soils and disturbed soils that have been organically amended not only retain much more stormwater, but they also serve as effective biotilters for urban pollutants and, by supporting more vigorous plant growth, reduce the ��-ater, fertilizer and pesticides needed to support installed landscapes. Topsoii does not include any subsoils but only the material from the top se��eral inches including organic debris. COi7lIlllUllS Of • �lative soils should be left undisturbed to the maximum extent t'se practicable. Native soils disturbed during clearing and grading should be restored, to the maximum extent practicable, to a condition where moishue-holding capacity is equal to or better than the original site conditions. This criterion can be met by using on-site native topsoil, incorporating amendments into on-site soil, or itnporting blended topsoil. • Topsoiling is a required procedure when establishing vegetation on ;hallow soils, and soils of critically low pH (high acid) levels. • Stripping of existing, properly functioning soil systein and vegetation for the purpose of topsoiling during construction is not acceptable. If an existing soil system is h�nctioning properly it shall be preserved ili its undisturbed and uncompacted condition. • [�epending on where the topsoil comes from, or what veaetation was on site before disturbance, invasive plant seeds may be included and could cause problems for establishing native plants, landscaped areas, c�r grasses. • Tapsoil from the site will contain myconhizal bacteria that are r�ecessary for healthy root growth and nutrient transfer. These native myconhiza are acclimated to the site and will provide optimum eonditions for establishing grasses. Commercially available mycorrhiza products should be used when topsoil is brought in from off-site. Design u�id if topsoiling is to be done, the following items should be considered: Installatin» �qaximize the depth of the topsoil wherever possible to provide the Specificatio�ls • ,�laximum possible infiltration capacity and beneficial growrth »iediu�n. Topsoil depth shall be at least 8 inches with a minimum organic content of 10 percent dry weight and pH between 6.0 and 8.0 c�r matching the pH of the undisturbed soil. This can be accomplished cither by returning native topsoil to the site andlor incorporating ��rganic am js��r��ndments should be incorporated to a rninimt�m -,� c��pj��c,��t�here tree roots or other natural V /�J UIL ___ _ _ -- - - — — February 2005 Vclume 11— Constructron StormwaFer Po!lutron Prevention 4-29 features limit the depth of incorporation. Subsoils below the 12-inch depth should be scarified at least 2 inches to avoid stratified layers, ��here feasible. The decision to either layer topsoil over a subgrade or incoiporate topsoil into the underlying layer may vary depending on the planting specified. • If blended topsoil is imported, then fines should be limited to 25 percent passing througi� a 200 sieve. • The final composition and constniction of the soil system will result in a natural selection or favoring of certain plant species over time. For example, recent practices have shown that incorporation of topsoil n�ay favor grasses, while layering with mildly acidic, high-carbon amendments may favor more woody vegetation. • Locate the topsoil stockpile so that it meets specifications and does not interfere with work on the site. It may be possible to locate more than one pile in proximity to areas where topsoil will be used. • Allo�� sufficient time in scheduling for topsoil to be spread prior to seeding, sodding, or planting. • Care must be taken not to apply to subsoil if the two soils have contrasting textures. Sandy topsoil over clayey subsoil is a particularly poor combination, as water creeps along the junction between the soil layers and causes the topsoil to slough. • If topsoil and stibsoil are not properly bonded, water wil] not infiltrate � tlle soil profile evenly and it will be difficult to establish vegetation. The best method to prevent a lack of bonding is to actually work the topsoil into the layer below for a depth of at least 5 inches. ' • Ripping or re-structuring the subgrade may also provide additional henefits regarding the overal] intiltration and interflow dynamics of ,, the soil system. ' • }-'ield exploration of the site shall be made to determine if there is stirface soil of sufficient quantity and quality to justify stripping. "Topsoil shall be friable and loam_y (loam. sandy loam, silt loam, sandy clay loam, clay loam). Areas of natural ground water recharge should be avoided. • Stripping shall be contined to the immediate construction area. A 4- to 6- inch stripping depth is common, but depth may vary depending on the particular soil. All surface runoff control structures shall be in place prior to stripping. Stockpiling of topsoil shall occur in the following manner: • Side slupes of the stockpile shall not exceed 2:1. • An interceptor dike with gravel outlet and silt fence shall surround all topsoil stc�Q�s ��f��c[�r 1 and April 30. Between ��Iay 1 FOR ASBUILT 4-30 Volurne !!- Construction Stormwater Po!lution Prevention February 2005 � and September 30, an interceptor dike with gravel outlet and silt fence shall be installed if the stockpile will remain in place for a longer period of time than active construction grading. • Erosion control seeding or covering with clear plastic or other mulching materials of stockpiles shall be completed within 2 days (October 1 through April 30) or 7 days (May 1 through September 30) of the formation of the stockpile. Native topsoil stockpiles shall not be covered �ith plastic. I • Topsoil shall not be placed while in a frozen or muddy condition, when the subgrade is excessively ��vet, or when conditio�ls exist that may otherwise be detrimental to proper grading or proposed sodding � or seeding. • Previously established grades on the areas to be topsoiled shall be maintained according to the approved plan. • When native topsoil is to be stockpiled and reused the following should apply to ensure that the mycorrhizal bacterial, earthworms, and other beneficial organisms will not be destroyed: 1. Topsoil is to be re-installed within 4 to 6 weeks; 2. Topsoil is not to become saturated with water; 3. Plastic cover is not allowed. ,'�laintenance • Inspect stockpiles regularly, especially after large storn� events. I Standards Stabilize any areas that have eroded. _� . � ' �_� �`� . �_1 '-� � , f � NOT UPDATED FOR ASBUILT February 2005 Volume !!— Construction Sformwater Po!lution Prevention 4-31 BMP C140: Dust Control Purpose Dust control prevents wind transport of dust from disttirbed soil surfaces onto roadways, drainage ways, and surface waters. Cnirditions of'L�se • In areas (including roadways) subject to surface and air movement of dust where on-site and off-site impacts to road��ays, drainage ways, or surface waters are likelv. Desigjr a��d • Vegetate or mulch areas that «-i11 not receive vehicle traffic. In areas InstaUatioit �vhere planting, rnulchi��" or pa��n� i� in�pr�actical_ a��l}� ��ra��el or Specifrcatioirs landscaping rock. • Litnit dust generation b}� �lear�ng only tl�ose ar�as where immcdi�t� activity ��vill take place, leaving the remainin� area(s) in the origin��l C011dltlOil. :�� >1�1h�C ��'1�i1111�1:11 (�1C' ��1'1�?117:i� �?IC);llll� �C1\�1 d� �Q1:'! ;1� practical. • Construct natural ur artifi�ial �in�lbrcak� e�r ��ul�screen;. I i��e n�a� be designed as enclosures for small dust sources. • Sprinkle the site with water tmtil surface is wet. Repeat as needed. To prevent carryout of mu�i onto �trcet_ rcl�er to Stabilizc�i C'on�tnicuon Entrance (Bti4P C 105 i. • Irrigation �vater can be usc;�i for dust control. lr-rigat�on systems �houl�i be installed as a tirst step on sites where dust control is a concern • Spray exposed soil areas ��ith a dust palliative, fallowin� the manufacturer's instructions and cautions regarding handling anci application. Used oil is prohibited from use as a dust suppressant. Local governments may approve other dust palliatives such as calciun; chloride or PAM. • PA;�1 (BMP C 126) added to water at a rate of 0.5 lbs. per I,OOi i gallons of water per acre and applied from a ��ater truck is morc erfective than water alone. This is due to the increased infiltratic�n ��! water into the soil and reduced evaporation. ln addition, sma]] soi i particles are bonded together and are not as easily transported by �•� : Adding PAM may actually reduce the quantity of water needed f�� dust control, especially in eastern �'�'ashington. Since the ��liole��l�� cost of PA�7 is about $ 4.00 �er p��und. thi; i�, an extr�n��lti- c��ct- effective dust control methu�. Techniques that can be used for unpu��cd road� an�l l��t> >nclt�a�: • Lower speed limits. High vehicle speed increases the acnotint ��f�du�t stirred up from unpa�•ed roads and lots. • Upgrade the road surface strength by improving particle size, shape, and minerNO�sUPDAT�De surface and base r7�aterial�. FOR ASBUILT - - - ---- - - ___ __ 4-40 Volume 1!— Construction Stormwater Polfution P.�evention February 2G05 • A�id surface �ra�-el tc� rcduce the ��urre of�iu�t �mis>>on. Limit the amount of fine E�articles (those smal(er than .07� mm) t� 1 U to 2O percent. • Use geotextile iabrics to increase the strength of ne�v roads or roads undergoing reconstruction. • Encourage the use of alternate, paved routes, if available • Restrict use by tracked ��ehicies and heavv t�z�cks to ��re�e�lt d�in�a;�� to road surface and base. • Apply chemical dust sup��res;ant, using th� aclmix method, blending the product with the top few inches of surface materiaL Suppressants may also be applied as surface treatments. • Pave unpaved pernlanent roads and other traf�fickcd areas. • Use vacuum street sweepers. • Remove mud and other dirt pramptly so it does not dry and thc�l t�u-r� into dust. • Limit dust-causing ��ork on windy days. • Contact your local Air Pollution Control Authority for guidance and ,raining on other dust control measures. Compliance with the local .Air Pollution Contro] Authority constitutes compliance with this BMP. .11ai�rte�ru�rc•e Respray area as necessa�y to keep dust to a minimum. St�r�r rlar-d.c NOT UPDATED FOR ASBUILT --- -- - --- -- - - - - - - - -- February 2005 Volume !1- Construction Stonnwater Polfution Prevention 4-41 4.2 Runoff Conveyance and Treatment BMPs BMP C200: Interceptor Dike and Swale Pur•pose Provide a ridge of compacted soil, or a ridge with an upslope s��ale, at the top or base of a disturbed slope or along the perimeter of a disturbed construction area to convey stormwater. t?se the dike and/or swale to intercept the runoff from unprotected areas and direct it to areas where erosion can be controlled. This can prevent storm runoff from entering the work area ar sediment-laden rlinoff from leaving the construction site. � Conditiorrs o Use Vl here the ninoff from an ex osed site or disnirbed slo e must be conve ed .f r P Y to an erosion control facility which can safely convey the storn�water. • Locate upslope of a construction site to prevent runoff from entering disturbed area. • When placed horizontally across a disturbed slope, it reduce� the amount and velocity of runoff flowing down the slope. • Locate downslope to collect runoff from a disturbed area and direct it to a sediment basir�. Design u�rd • Dike and/or swale and channel must be stabilized with temporary �� Ii�slal/atinn pennanent vegetation or other channe] protection during construction. Specificutio�rs . Channel requires a positive grade for drainage; steeper grades require channel protection and check dams. • Review construction for areas where overtopping may occur. • Can be used at top of new fill before vegetation is establishe�i • May be used as a pernianent diversion channel to carr-�� the run��t; • Sub-basin tributary area should be one acre or less. • Design capacity for the peak flo��v from a ]0-year, �'-i-h�,u, ,t�,rn,. assuming a Type 1 A rainfall distributioti, for temporary facilit�e� Alternatively, use l.6 times the 10-year, 1-hour flow indicated hti �in approved continuous nmoff model. For facilities that will al�o �cr�� on a pern�anent ha:i�, c��ncult thc local ��ernment'� draina�c requirement:. Interceptor dikcs ;l�;�li m:�t the 1oli�'��.�in�� c��it�r;;� Top Width 2 feet minimum. Height 1.5 feet min�nlu�n on be►�n. Side Slope 2:l or flatter. Grade Depends on t��po�raE�h��, }�o�ti�crcr. dikc ;y;tem minimu»> i� 0.5%. maximlim is l°�o. Compaction Minimum of 90 percent ASTM D698 standard proctor. NOT UPDATED FOR ASBUILT - - - -- - -- - -- -- - -------- _--- February 2005 Volume 11— Censtrucfion Stormwafer Pollutron Prevenbon 4-57 Horizontal Spacing of Interceptor Dikes: Average Slope Slope Percent Flowpath Length 20H:1 V or]ess 3-5% 300 feet (l0 to �0)H:1 V 5-10% 200 feet (4 to 10)H:1 V I 0-25°io l 00 feet (2 to 4)H:1 V 25-50% 50 feet Stabilization depends on velocity and reach Slopes <5% Seed and mulch applied within 5 days of dike , construction (see BMP C121, rllulclzi��g). Slopes 5 -40% Dependent on runoff velocities and dike materials. Stabilization should be done immediatelv using either sod or riprap or other measures to avoid erosion. . The upslope side of the dike shall provide positive drainage to the dike outlet. No erosion shall occur at the outlet. Provide energy dissipation measures as necessary. Sediment-laden runoff�nust be released through a sediment trapping facility. • Minimize construction traffic over temporary dikes. Use temporary ; cross culverts for channel crossing. ' Interceptor s�vales shall meet the following criteria: Hottom VVidth 2 feet minimum; the bottom shall be Ie��eL Depth 1-foot minimum. Side Slope 2:1 or flatter. Grade Maximum 5 percent, with positive drainage to a suitable outlet (such as a sediment pond). Stabilization Seed as per B:�1P C120, Tentpo�•ary and Pef-ma��ertt Seeding, or BMP C202, Channel Li�ting, 12 inches tl�ick of riprap pressed into the bank and extending at lea5t 8 inches vertical from the bottom. • Inspcct divcrsii�n dikes and interceptor swales once a week and after every rainfall. Immediately remove sedi�nent from the flo«• area. • Damage caused by construction t�•affic or other activity must be repaired before the end of each working day. C'heck outlets and make timely repairs as needed to avoid gully formation. When the area below the temporary diversion dike is permanently stabilized, remo�°e the dike and fill a�id stabilire the channel to blend with the natural siirface. NOT UPDATED FOR ASBUILT --- - - - -- --------- -- - - - --- 4-58 Volume ll- Constructron Stormwafer Pollufror� Preventron February 2005 BMP C201: Grass-Lined Channels Pr��pose To provide a channel with a vegetative lining for conveyance of runoff. See Figure 4.7 for typical grass-lined channels. Cnnditio��s of Use This practice applies to constniction sites where concentrated runoff need� to be contained to prevent erosion or flooding. • When a vegetative lining can provide sufficient stability for the channel cross section and at lower velocities of water (normally dependent on grade). This means that the channel slopes are genea-aliv less than 5 percent and space is available for a relatively large cro�: section. • Typical uses include roadside ditches, channels at property b��undarie:. outlets for diversions, and other channels and drainage ditches in fo�� areas. • Channels that will be vegetated should be installed before major earth«ork and hydroseeded with a bonded fiber matrix (BFM). The vegetation should be v��ell established (i.e., 75 percent cover) before water is allowed to flow in the ditch. VVith channels that will ha�c high flows, erosion control blankets should be installed over th� liydroseed. if vegetation cannot be established from seed befor� ��t�r- is allowed in the diteh, sod shotild be il�s+.alled in thc h��ttom ��I�th�� ditch in lieu of hydromulch and blankets. Desig�r and Locate the channel whcre it �an c��nfo►-m t�� th� t,�p��-�r,,��l��: �.n�j �>tl�cr I,rstallation features such as road;. Specifrcatinns • Locate them to use natural cirainage �ystems to the gre<itest e�t�nt possible. • Avoid sharp changes in alignment or bends and chan�c� in ��r,��je • Do not reshape the landscape to fit the drainage channci • The maximum design ��elocity shall be based on soil �c�nc:�t�,>>>�. t� of vegetation, and method of reve�etation, but at no times shall velocity exceed 5 feet;'second. The channel shall not be ovei-topp� the peak runoff from a 10-year, 24-hour storm, assuming a Type 1 A rainfall distribution." Alternatively, use 1.6 times the 10-year, 1-hour flow indicated by an approved continuous runoff model to determin� a flow rate which the channel Inust cantain. • Where the grass-lined channel will aiso functit�n a� a per�na»�nt stormwater eonveyance faeility, consultant the cirainage conve��ance requirements of the local government with jurisdiction. • An estabtished grass or vegetated lining is required before the channel can be used to convey storn�w-ater, unless stabilized with netc or blankecs. NOT UPDATED FOR ASBUILT __ - -- — _ _ ---- --- — _- February 2005 Volume Il- Construcfion Stormwater Pol�utior, Prevent�on 4-59 • If�design velociry of a channel to be vegetated by seeding exceeds 2 ft/sec, a temporary channel liner is required. Geotextile or special mulch protection such as fiberglass roving or straw and netting provide stability until the vegetation is fully established. See Figure 4.9. • Check dams shall be removed when the grass has matured sufficiently to protect the ditch or swale unless the slope of the swale is greater than 4 percent. The area beneath the check dams shall be seeded and mulched immediately after dam removal. • If vegetation is estabiished by sodding, the pern�issible velocity for established vegetation may be used and no temporary liner is needed. • Do not subject grass-lined channel to sedimentation from disturbed areas. Use sediment-trapping BMPs upstream of the channel. • V-shaped grass channels generally apply where the quantity of water is small, such as in short reaches along roadsides. The V-shaped cross section is least desirable because it is difficult to stabilize the bottom ��vhere velocities may be high. • Trapezoidal grass channels are used where runoff volumes are large and slope is low so that velocities are nonerosive to vegetated linings. (Note: it is difficult to construct small parabolic shaped channels.) • Subsurface drainage, or riprap channel bottoms, may be necessary on � sites that are subject to prolonged wet conditions due to long duration flows or a high water table. • Provide outlet protection at culvert ends and at channel intersections. • Grass channels, at a minimum, should carry peak runoff for temporary construction drainage facilities from the 10-year, 24-hour stoi-m without eroding. VJhere flood hazard exists, increase the capacity according to the potential damage. • Grassed channel side slopes generally are constructed 3:1 or flatter to aid in the establishment of vegetation and for maintenance. • Construct channels a minimum �f 0.2 foot larger around the periphery to allow for soil bulking during seedbed preparations and sod buildup. :'�Inirrteirance nuring the establishment period, check grass-lined channels after every Stnnclurds rainfall. • After grass is established, periodically check the channel; check it after every l�ea�y rainfall event. Immediately make repairs. • It is particularly important to check the channel outlet and all road crossings for bank stability and evidence of piping or scour holes. • Remove all significant sediment accumulations to maintain the designed carrying capacity. Keep the grass in a healthy, vigorous condition a� �j]��$�j,qc.`�i,�}s�e primary erosion protection for the channel. IV lJ lJ LJf� I C FOR ASBUILT ------- _- -- - - - 4-60 Volume 1!- Construction Stormwater Pollution Prevention February 2005 Typical V-Shaped Channel Cross-section � , ,:� �;,,; ..,�< , �� ?�iL;,•, � � , ,> �%j` , � ��`% � /\ '�'�� ! i��.��,� ��\\j��.i� . }\i�\�� ^'\\ \� . ��,�/' y//\ i !T�%\%��'.� �"��'��j\/ .� � `�. � , � � /i��f�\�/�/j, i`��. . /� ��,�c%,'� �_6,�_9� ; • �� .. ��,;.:. � \ Filter� \��•� '� �� 150-225mm) Fabric ��i��\\ Key in Fabric Grass-Lined � With Rock Center Typical Parabolic Channel Cross-Section ��;� �- 'lr�� u�.��.��'��-_�. �=r` r��l.(��; �F�', ��`� ��i1 �A��.�T��. %�, ,, ;'`;�, ,� ,� � �� ,� :, %�! ��/i��!�,.� .,a\�ti�.\\\ � , '� �� '�� ;,lii�.�'; ,��,. g��_g��,� T\'. \/\\,;j/\;;\%�\\/ (150-225mm) � \i/, � �;i��Filter � Key In Fabric / 1 �� Fabric , — With Channel Liner - With Rock Center for Base Flow Typical Trapezoidal Channel Cross-Section , , � �.�.,� Li1�v; � ' � „ d�,:'k�A v1�J�V ei�/�� ' % - , �- Design Depth �� /��/'� ''l. , / \�� / �%' %/�: \�i\ " r ��'�� f ��\��/� ,�, / �.�� . � i /��.� � lV�� r11�' ,d) �rV1�r �I W14�1��5��11.\'��\1�� /,�• vercut channel 2" (50mm�� -� , ,/, /�//; to allow bulking during �,�\�.\�,�\�� \�-�\� seedbed preparation � !:\/��. and growth of vegetation. '� With Rock Center For Base Flow Filter Fabric J Figure 4.8-Typical Grass-Lined Channels NOT UPDATED FOR ASBUILT February 2005 Volume !!- Consfruction Stormwater Pollution Prevention 4-61 �'�.; �Overlap 6" (150mm) minimum .�� \� i,�: ` �1;.� � � �; �1�� \ '• r, r, Excavate Channei to Design . /', �� ,,,, ;•. %�� ' Grade and Cross Section _ ��r"� /i� ��' ,A� � �V` � � � \��:�.' -. � .��'\�� %��• � �, ,� ' �� ,.; Design Depth `� � . Ol/ERCUT CHANNEL `''-� �� 2"(SOmm)TOALLOW Longitudinal � / /� �'�� I, ,11f .V, .iU ��\ry anchor trench BULK/NG DUH/NG SEEDBfO i PREP.4HAT/ON — �� /�/�..�j��/,/,ii � � i �1 � �� s'�tsomm> TYP/CAL /NSTALLAT/ON �-�� W/TH EROS/ON CONTROL ` ��/�f /��j/ •�. � �/ /i\/ BLA/VKETS OR TURF �' ,��; � �•� �,��-��'�; ��\�• \� ' ° ��\�� . RE/NFORCEMENT MATS �'�� '� �� " //\//\/'�,� �\//\;j, \��\��\� � \��,� �\\,��\\�1 somm) /�\/�\\/\\� \\//'\\//\\//\ 6 � �//\�/��I �.. /�//� 'V\/�`/,\(15Amn/ � /�\/�� Intermittent Check Slot Longitudinal Anchor Trench Shingle-lap spliced ends or begin new roll in an intermittent check slot �, -� � ��- Prepare soil and apply seed before O � installing btankets, mats or other � " x LL �" temporary channel liner system � / �, � � � " � � w�, �, ,� ,. ,,�, ,,�, � � � 4� � � i ,.� ;. „ � ' �l � � /� / ` / - - - - - - - , � � /,�//� �.� �%> �' ' /i��.-- �� ,��j.,� �, � . �\.� 1� ��/� �" \� , } � � i;� \ �• \� �� , , �C j \ � .,- � ;,,\\//�//\\/////\\/�/ NOTES: 1. Design velocities exceeding 2 ft/sec(O.Sm/sec)require temporary blankets,mats or similar liners to protect seed and soil until vegetation becomes established. 2. Grass-tined channels with design velocities exceeding 6 ft/sec(2m/sec)should include turf reinforcement mats. Figure 4.9—Temporary Channel Liners FOR ASBUILT i 4-62 Volume!1—Construction Stormwater Pollution Prevention February 2005 I BMP C204: Pipe Slope Drains Purpose To use a pipe to convey stonnwater anytime water needs to be diverted away fi-om ar over bai-e soil to prevent gullies, channel erosion, and saturation of slide-prone soils. Co�rditions of L'se Pipe slope drains should be used when a temporary or permanent stormwater conveyance is needed to move the �vater down a steep slope to avoid erosion (Figure 4.10). Ot� highway projects, they shotild be used at bridge eiids to collect runoff� and pipe it to the base of the fill slopes along bridge approaches. These can be designed into a project and included as bid items. Another use on road projects is to collect ninoff from pavement and pipe it away from side slopes. These are useful because there is generally a time lag L�et�tecn ]iaving the first lift of aspl�alt installed and the curbs, gutters, and pernianent drainage installed. Used in conjunction with sand bags, or other temporary diversion devices. thece ��ill prevent massi��e an�ount. c�1� sediment from leaving a project. Water can be collected, channeled ��ith sand bags, �Triangular Silt I�ike;. bern�s, or other material, and piped to temporary sediment pond�. Pipe sJope drains can be: • Connected to �iew catch basins a��d useci teir�purarily unti] all pern�anent piping is installed; • Used to drain water collected from aquifers exposed on cut �1:�}�e� �,n�i take it to the base of the slope; • Lsed to collect clean ruiloff from plastic sheetins� and direct n :�•,;.;� from exposed soil: • installed in conjunction ��°ith �ilt fcncc to drain collcct�i ��atcr to �� controlled area; • Used to divert small sea,��nal ,tream: u�ti�a}� fi��m con�truct��,n. The�� have been used successfully on culvert replace�nent and extension jobs. Large flex pipe can be used on ?ar,�r 5trcam� �lur�� ul��rt removal, repair, or replacement; and, • Connected to existing down spouts an�1 ��f�irain, .�nci u�«i ;�� j��rt water away fi�om work arcas during building rcnovati��i�. deit��lition. and construction projects. There are now several commercially available collect�,r• that �re att��hcd t� the pi�e inlet and help pre��ent erosion at the inl�;. NOT UPDATED FOR ASBUILT February 2005 Volume ll- Consfruction Stormwafer Pollubon P�ever,tron �-67 Desi�ln uud Sire the pipe to com�ey the flo�1�. The capacity for ternpurary drains shall b� Installation sufficient to handle the peak flow from a 10-year, 24-hour storn� event, Specifications assuming a Type l A rainfall distribution. Alternatively, use 1.6 times thc 10-year, 1-hour flow indicated by an approved continuous runoff model. Consult local drainage requirements for sizing permanent }�ipe sl�p� dr��i:1�. • i;se care in clearing vegetated slopes for installation. • Re-establish cover immediately on areas disturbed b� in�tallation. • Use temporary drains on new cut or fill slopes. • Use diversion dikes or swales to collect water at the top of th� slope. • Ensure that the entrance area is stable and large enough to direct flo�� into the pipe. . Piping of water through the berm at the entrance area is a comtno» failure mode. • The entrance shall consist of a standard flared end section for culvei-ts l2 inches and larger with a minimum 6-inch metal toe plate to pre��ent runoff from undercutting the pipe inlet. The slope of the entrance shall be at least 3 percent. Sand bags may also be used at pipe entrances as a temporary measure. • The soil around and under the pipe and entrance section shall bc � thoroughly compacted to prevent undercutting. • The flared inlet seccion shall be securel�� connected to the slo�c drain . } and have watertight connecting bandc. • Slope drain sections shall be securely tiistened togethcr. fused or iza�e gasketed �vaterti�ht fittin4s, and shall h� securcly allchoi�ed intu the soil. � � • Tl�rust blocks sliould be in�tailed an��time 90 �e��ree bends ar-e utilii�d. Depending on size of pipe and i7o��, these can be constructed with � sand l�a«s. stra«� hales staked in place. "t" p��sts and ��ire. <�r ecolo�,�� blocks. • Pipe needs to be �ecured alon� its full Icn;�th to ��rz��ent mi��ement. This can be done with steel "t" posts and wire. A post is installed on each side of the pipe and the pipe is wired to them. This should be ' done every 10-20 feet of pipe length or so, depending on the size of the pipe and quantity of water to diverted. • Interceptor dikes shall be used to direct runoff into a slope drain. The height of the dike shall be at least 1 foot higher at all points than the top of the inlet pipe. • The area below the outlet must be stabilized with a riprap apron (see B��IP C209 Outlet Protection, for the appropriate outlet material). NOT UPDATED FOR ASBUILT 4-68 Volume 1!— Consfruction Stormwater PolJution Prevention February 2005 • If the pipe slope drain is conveying sediment-laden water, direct all flows into the sediment trapping facility. • Materials specifications for any permanent piped system shall be set by the local government. Maintenance Check inlet and outlet points regularly, especially after storms. Standards The inlet should be free of undercutting, and no water should be going around the point of entry. If there are problems, the headwall should be reinforced with compacted earth or sand bags. • The outlet point should be free of erosion and installed with appropriate outlet protection. • For permanent installations, inspect pipe periodically for vandalism and physical distress such as slides and wind-throw. • Normally the pipe slope is so steep that clogging is not a problem with smooth wall pipe, however, debris may become lodged in the pipe. Dike material compacted 90°/a modified proctor CPEP or equivalent pipe i=<<i i��(�� Interceptor Dike 1�11�f- '��,� _ I I=I I I— t z• MIN.� I � — Provide riprap pad Z- � —=�� or equivalent energy �— dissipa6on � Discharge to a stabilized Standard flared watercourse,sediment retention end section faciliiy,or stabilized outlet Inlet and all sections must be securely fastened together with gasketed watertight fittings Figure 4.10- Pipe S(ope Drain NOT UPDATED FOR ASBUILT February 2005 Volume 1!—Consfruction Stormwater Pollution Prevenfion 4-69 BMP C208: Triangular Silt Dike (Geotextile-Encased Check Dam) Purpose Triangular silt dikes may be used as check dams, for perimeter protection. for temporary soil stockpile protection, for drop inlet protection, or as a temporary interceptor dike. Conditions of use May be used in place of straw bales for temporary check dams in ditches of any dimension. • :Vlay be used on soil or pavcmcnt with adhesive or sta�les. • TSDs have been used to build tem��orary: 1. sediment ponds; 2. diversion ditcl�es: 3. concrete wash out facilities: 4. curbing; 5. water bars; 6. level spreaders; and. 7. berms. Desig�: a�zd Made of urethane foa»� se��n into a ��ven geosynthetic tabric. Installatio�r It is triangular, l0 inches to 14 inches high in the center, with a ?O-inch to Specificaiions 2g_�nch base. A 2—foot apron extends beyond both sides of the triangle along its standard section of 7 feet. A sleeve at one end allo��•s attachment of additional sections as needed. • Install ��ith ends cur�ed up ti� E�re��nt �a�ater ti�om 11o�ti��n� around tl�c ends. • The fabric flaps a»d check dam units are attached to the grotmd ��ith wire staples. Wire staples should be No. 1 I gauge wire and should be ' 200 mm to 300 mm in length. • V�'hen multiple units are installed, thz sleeve of fabric at the end of the unit shall overlap the abutting unit and be stapled. • Check dams should be located and installed as soon as construction will allow. • Check dams should be placed perpendicular to the flow of water. • When used as check dams, the leading edge must be secured with rocks, sandbags, or a small key slot and staples. • In the case of grass-lined ditches and swales, check dams and accumulated sediment shall be removed when the grass has matured sufficiently to protect the ditch or swale unless tlle slope of the swale is greater than 4 percent. The area beneath the check dams shall be seeded and rnulched immediately aCter dam reino��al. Mnintencrnce • Triangular silt dams shall be monitored for performance and sediment St��rdards accumulati��u�ir��i��[��c i iunoff producing rainfall. FOR ASBUILT 4-78 Volume N- Construction Stormwater Pollution Prevention February 2005 Sediment shall be removed ��•hen it reaches one hali�thc hei�ht of the dam. � • Anticipate submergence and deposition above the triangular silt dain and erosion from high flows around the edges of the dam. Immediately repair any damage or any undercutting of the dam. NOT UPDATED FOR ASBUILT February 2005 Volume 1!— Construction Stormwater Pollution Preventron 4-79 BMP C220: Storm Drain Inlet Protection Puipose To prevent coarse sediment from entering drainage ,ystcm� prior to pernlanent stabilization of the disturbed area. Conditions of Use VVhere storni drain inlets are to be made operational before pennanent stabilization of the disturbed drainage area. Protection should be provided for all storm drain inlets downslope and within 500 feet of a disturbed or construction area, uilless the runoff that enters the catch basin will be conveyed to a sedime�lt pond or trap. Inlet protection may be used anywhere to protect the drainage systern. It is likel� that the drainage system will still require cleaning. Table 4.9 lists several options for inlet protection. All of the rliethod� fi+r storm drain inlet protection are prone to plugging and require a high frequency of maintenance. Drainage areas should be limited to 1 acre c�r less. Emergency overflows may be required where stormwater pondin`� would cause a hazard. If an emergency overflow is provided, additional end-of-pipe treatment may be required. Table 4.9 =- ' Storm Drain Inlet Protetion Applicable for Type of Inlet Emergency Paved! Earthen Protection Overflow Surfaces Conditions of Use Dro Inlet Protection Excavated drop inlet. Yes. Earthen Applicable for heav�- flows. Easy prot.ection temporar}� to maintain. Large ar�ea flooding will Requirenient: 30' X 30'/acre occur Block and gravel drop 1'es Paved or Earthen Applicable for heavy concentrated inlet protection flows. Will not pond. ('Travel and wire drop No Applicable for heav}� concentrated inlet protection flows. Will pond. Can withstand traffic. Catch basin filters Yes Paved or Earthen Fre uent maintenance re uired. � Curb Inlet Protection ' Curb inlet protection Small capacit�� Paved Used for sturdy, more compact with a wooden weir overflow installation. Block and gravel curb Yes Paved Sturdy. but limited filtration. inlet protection Culvert Inlet Protection Culvert inlet seditnent 18 month expected life. ' tra NOT UPDATED FOR ASBUILT 4-82 Volume 1!— Constructron Stormwater Pollution Prevention February 2005 Design and Lzcnl crtc�d Dro� Ir�let Protc�ctro�r - An excavated impou»dment around the I►:stallutio►r storn� drain. Sediment settles out of the storn�water prior to entering the Specifications storm drain. • Depth 1-2 ft as measured from the crest of the inlet structure. • Side Slopes of excavation no steeper than 2:]. . 'vlinimum volume of exca��ation 35 cubic yards. • Shape basin to fit site with longest dimension oriented toward the longest inflow area. • Install provisions for draining to prevent standing water problems. • Clear the area of al] debris. • Grade the approach to the inlet uniforn�ly. • Drill weep holes into the side of the inlet. • Protect weep holes witi� screen wire and washed aggregate. • Seal weep holes when removing structure and stabilizing area. • It may be necessary to build a temporary dike to the down slope side of the stn�cture to prevent bypass flow. Block and Gra��el Filter- A barrier forn�ed around the storm drain inlet ��ith standard concrete hlocks and gravel. See Figure 4.14. • Height 1 to 2 feet above inlet. � • Recess the first row 2 inches into the ground for stability. • Support subsequent courses by placing a 2x4 throu�h the block opening. • Do not use mortar. • Lay some blocks in the bottom row on their side for dewatering the pool. • Place hard�vare cloth or comparable wire mesh with '��-inch openings over all block ope�iings. • Place gravel just below the top of blocks on slopes of 2:1 or flatter. • An alternative desian is a gravel donut. • Inlet slope of 3:1. • Outlet slope of 2:1. • 1-foot wide level stone area between the structurc and the ir�let. • Inlet slope stones 3 inches in diameter or larger. • Outlet :lopc use ��ra�el '��- to '��-inch at a minim�nl� thic�;ne�, ��i� 1-t«�,t. NOT UPDATED FOR ASBUILT FP.b�uarv 2005 Volume ll- Cons!ructron Stor,mwater Pollution P.reve��tion 4-83 Plan View A Drain Grate �,.,��oo�o!o� 'O�,� p��;� .�a ,� �'°o, �1 o`��oa�fl� '��'�a�,oo, 'Oo: o�o C��°��. o�� s� ��Jo 0 00 0.o ,o :� • o �°�4 �� °�o�o �;;o. a � a:Oq �p,` Concrete �-�d�;,p ,��j`� ,po Block ;�• �oO�O'D• �� O O�0 ��. 4 Q^ oQ. o Q � o Jt° �00�0� �'� .aa�o �'�� 0 O�O�V� .a �� o�o a0�. ° Gravel d•�'�'��i�o �'� .�4.�J o Backfill t�°��4�:� ' 4�° �n�p�, C��o ��O K]�� pG��o �,�� '�0�� Qi��CQ�°°o. '�'�r`J oa Qo°o�.O�` �:��oo OQ�p �O O'� o v�o�•{e � C a.� OoO��C�� OOV.0 ra0 � A �y5 ��oQ � � h Section A � A Concrete Block Wire Screen or Filter Fabric Gravel Backtill- Overflow � Water Ponding Height �.a -- o � �-�Water j ' •`� po \�\�\�\�\.o° �\ � \ \ \�\�\��,- `i�/�\�jj�jj�j j j//y/\ - \��%/\\��%��\/�\/��i; �,��,�\��\/�\�� Drop Inlet \\��j��\��%�\ . /i<,, �/\�� /\/.�/i�/� \��j�, \//\/� Notes: 1.Drop inlet sediment barriers are to be used for small,nearly level drainage areas.(less fhan 5%) 2.Excavate a basin of sufficient size adjacent to the drop inlet. 3.The top of the structure(ponding height)must be well below the gound elevation downslope to preveat runoff from bypassing the inlet. A temporary dike may be necessary on the dowslope side of the swcture. Figure 4.14-Block and Gravel Filter Gravel and Wire Mesh Filter- A gravel barrier placed over the top of the inlet. This structure does not provide an overflo��. • Hardware cloth or comparable ��ire mesh with '!-inch openings. • Coarse aggregate. • Height 1-foot or more, 18 inches wider than inlet on all sides. • Place wire mesh over the drop inlet so that the wire extends a minimum of l-foot beyond each side of the inlet structure. • If more than one strip of inesh is necessary, overlap the strips. • Place coarse aggregate over the wire mesh. • The depth �r��q�d��t least 12 inches over the entire inlet openi e i'f��a inches on all sides. OR ASBUILT 4-84 Volume !!-Construction Stormwater Pollufion Prevention February 2005 Catclrbasr,� Filt��r�s - Inserts should be designed by the manufacturer i�or use at constnution sites. The limited sediment storage capacity increases the amount of inspection and maintenance required, which may be daily for heavy sediment loads. The maintenance requireinents can be rediiced by combining a catchbasin filter with another type of inlet protection. This type of inlet protection provides flow bypass �vithout overflow and therefore may be a better method for inlets ]ocated along active rights-of- ��ray. • 5 cubic feet of storage. • Dewatering provisions. • High-flo��r bypass that ��viil not clog under normal use at a construction site. • The catchbasin filter is inserted in the catchbasin just below t)le grating. Curb Inlet Protec�tion i1•ith YT'ooden N'eir Barrier formed around a curb inlet with a wooden frame and gravel. • Wire mesh with '/2-inch openings. • Extra strength filter cloth. • Constnict a frame. • Attach the wire and filter fabric to the frame. • Pile coarse washed aggregate against wire;"fabric. • Place weight on frame anchors. Bloc� mrd Gra��el Ci��b I�7let Protectio�� Barrier fonned around an inlet with concrete blocks and gravel. See Figure 4.14. • Wire mesh Wlt�l '/z-inch openings. • Place two concrete blocks on their sides abutting the curb at either side of the inlet opening. These are spacer blocks. • Place a 2x4 stud through the outer holes of each spacer block to align the tront blocks. • Place bloeks on their �ides acro�s the fi-i�nt of the inlet and aburting the spacer blocks. • Place wire mesli c,ver the otitside vertical face. • Pile coarse aggregate against the wire to the top of the barrier. Curb airc�Girttei�_Sedintejat Barrier•— Sandbag or rock bei7n (riprap and aggregate) 3 feet high and 3 feet wide in a horseshoe shape. See Figw-e 4.16. • Construct a horseshoe shaped berm, faced with coarse aggregate if� using riprap, 3 feet high and 3 feet wide, at least 2 feei from the inlet. • Constiuct a horseshoe shaped sedimentation trap on the outside of tl;� bernl size��ti��Dr/��'�ard� f��r �,rc�tec!in�� a cul�ert ir.l.t. FOR ASBUILT - - ----- ____ _ __ _- --- _ _. February 2005 Volume Il— Constructron Stormwater PolJution Preventron 4-85 ,�Yluintenanee • Catch basin filter� �hould be inspecti�l fi-equentl��, rspecially af�ter Stu�rdards storm events. If the insert becomes clogged, it shoiild be cleaned or replaced. • For systems using stone filters: Tf the stone filter becomes clogged ��ith sediment, the stones must be pulled away from the inlet and cleaned or replaced. Since cleaning of gravel at a construction site may be difficult, an alternative approach would be tc� use the clo�ged stone as fill and put fresh stone around the inlet. y • Do not wash sediment into storm drains while cicanin�. Spread all excavated material evenly ocer t}�e surrounding land area or stockpile and stabilize as appropriate. ' � � NOT UPDATED FOR ASBUILT 4-86 Volume !!— Consfruction Stormwater Pollution Prevention February 2005 Plan View Back of Sidewaik l� Catch Basin � — �-- ----- j: � 1' �� ,, 2x4 Wood Stud Back of Curb \-_ � Concrete Block Curb Inlet � �, -- �'�o • o�Q c �o� a o�� o..o .�'`�� " ��'�' P�� 4�p�p O� �o'Q '��, � ' '�. � '' O �� •..{y[,' a.a��n� i , � ��oQ,-�'. � og p � 'Q � o�f � ap,� 8�?0 .��`J O' OO��,��rF� 'Oo O' O" •' C'� Oa Oa 'O',� �'��'.��,. � � �'8�g°� �. '�o�. �� '°.-�� °� ��o�p o�o�?p�p. �vq�� op op� o�o'j.•o- �p. °�°��p-�°o�€.. '��,�4� o oO�Q�4 °4.,•°aD.o.�' °O�.��' Q�'' bJa�'�h�,o 7S gA CS�of�'' ��o.�?'�° ,��°��'o�. Wire Screen r A� Filter Fabric Concxete Block Section A � A ��`�Drain Gravel (20mm) 'h"Drain Gravel (20mm) Ponding Height Concrete Block Overfl � , � � ' ❑ �� —��_' :e Curb Inlet \/j\\' , ��/ ,/�/ � ��A Wire Screen or ��\��\�/\�\ � �\�/; Fifter Fabnc �'�\/�\'i�% //� ��,; i Catch Basin \�' 4 Wood Stud (100x50 Timber Stud) ; \� / i � ;��/ NOTES: 1.Use block and gravel type sediment barrier when curb inlet is located in gently sloping street segment, where water can pond and albw sediment to separate from runoff. 2.Barrier shall allow for overflow from severe storm event_ 3. Inspect barriers and remove sediment after each storm event. Sediment and gravel must be removed from the traveled way immediately. Figure 4.15-Block and Gravel Curb Inlet Protection FOR ASBUILT February 2045 Volume!!- Consfruction Stormwater Pollution Prevention 4-87 Plan View - - --__ _ ___ _ -- -- Back of Sidewalk Burlap Sacks to Catch Basin Overlap onto Curb �\ Curb Inlet --- '� Back of Curb� ,_ _ ---- _ _ _ _-- , _ _----- — , . �----- .___._ _ �_-- � — —- - �i��, � f — �`:j RUNOFF �{� _ ��— —�� : ------ -- -- �---;,�I � !� � ---- RUNOFF SPILLWAY; ;; � �\ � ;, ;.�; ----- — _ i . �Y��'� ,� � /j�> �i' _� / �/ � rf,�� =%/'// � '� ��' � '�'� �" Gravel Filled Sandbags ��\\� "��/�, Stacked Tightly �-_ �/:; . \`_, NOTES: I. Place curb type sediment barriers on gently sloping street segnents,where water can pond and allow sediment to separate from runoff: 2. Sandbags of either burlap or woven'geotextile'fabric,are filled with gravel,layered and packed tightly. 3. Leave a one sandbag gap in the top row to provide a spillway for overflow. 4. Inspect barriers and remove sediment after each storm event. Sediment and gravel must be removed from the traveled way immediately. Fi ure 4.16-Curb and Gutter Barrier NOT UPDATED FOR ASBUILT 4-88 Volume 11- Construction Sformwater Pollution Prevenlion February 2005 BMP C202: Channel Lining Purpose To protect erodible channels by providing a channel liner using either blankets or riprap. Conditions of Use When natural soils or vegetated stabilized soils in a channel are not adequat� to prevent channel erosion. • When a permanent ditch or pipe system is to be installed and a temporary measure is needed. • 1n almost all cases, synthetic and organic coconut blankets are tnore effective than riprap for protecting channels from erosion. Blankets can be used with and ��vithout vegetation. Blanketed channels can be designed to handle any expected flow and longevity requirement. Some synthetic blankets have a predicted life span of 50 years or more, even in sunlight. • Other reasons why blankets are better than rock include the availability of blankets over rock. In many areas of the state, rock is not easily obtainable or is very expensive to haul to a site. Blankets can be delivered anywhere. Rock requires the use of dump tn�cks to haul and heavy equipment to place. Blankets usually only require laborers with hand tools, and sometimes a backhoe. • The Federal High�ray Administration recommends not using flexible liners whenever the s(ope exceeds l0 percent or the shear stress exceeds 8 ibs/ftz. Desigir a►rd See BMP C 122 for inforn�ation on blankets. Installation Since riprap is used where erosion potential is high, construction must be Specifications sequenced so that the riprap is put in place ��ith the minimum possible dela��. • Disturbance of areas where riprap is to be placed should be undertaken only when final preparation and placement of tlle riprap can follow immediately behind the initial disturbance. Where riprap is used for outlet protection, the riprap should be placed before or in conjunction with the construction of the piUe or channel so that it is in place when the pipe or channel begins to operate. • The designer, after determining the riprap size that will be stable under the flo«1 conditions, shall consider that size to be a minimum size and then, based on riprap gradations actually available in the area, select the size or sizes that equal or exceed the minimum size. The possibility of drainage structure damage by children shall be considered in selecting a riprap size, especially if there is nearby water or a gully in which to toss the stones. • Stone for riprap shall consist of field stone or� quam� stone oi� approximately rectangular shape. The stone sha11 be hard and angular and of su��li��i y0��t di�inte��rate on exposiire t<� ��ater or FOR ASBUILT - - - - -- ----_---- -- Febrirary 2005 Volume ll-- Construct�on Stormvrater Pollutien Preventron 4-63 weathering alid it shall be suitable in all respects for the purpose intended. • Rubble concrete may be used provided it has a density of at least 150 pounds per cubic foot, and otherwise meets the requirement of this standard and specification. • A lining of engineering filter fabric (geotextile) shall be placed between the riprap and the underlying soil surface to prevent soil movement into or through the riprap. The geotextile should be keyed in at the top of the bank. • Filter fabric shall not be used on slopes greater than l-1!2:1 as slippage may occur. It should be used in conjunction with a layer of coarse aggregate (granular filter bJanket) when the riprap to be placed is 12 inches and larger. -, : � ; i : , � l - � __J , ` . , 1 -, I i ; ,_.� i � � �� NOT UPDATED FOR ASBUILT 4-64 Volume Il- Construction Stormwater Pollution Prevention February 2005 BMP C209: Outlet Protection Pr�rpose Outlet protection prevents scour at conveyance outlets and minimizes the potential for downstream erosion by reducing the velocity of concentrated stormwater flo��s. Conditiorrs of use Outlet protection is required at the outlets of all ponds, pipes, ditches, or other conveyances, and where runoff is conveyed to a natural or manmade drainage feature such as a stream, ��etland, lake, or ditch. Design r�nd The receiving channel at the outlet of a culvert shall be protected from Installati�n erosion by rock lining a minimum of 6 feet downstream and extending up Specifrcations the channel sides a minimum of 1—faot above the maximum tailwater elevation or 1-foot above the crown, whichever is higher. For large pipes (more than 18 inches in diameter), the outlet protection lining of the channel is lengthened to four times the diameter of the culvert. • Standard wing��alls, and tapered outlets and paved channels should also be considered ��hen appropriate for permanent culvert outlet protection. (See WSDOT Hydraulic Manual, available through WSDOT Engineering Publications). • Organic or synthetic erosion blankets, ��ith or without vegetation, are usually more effective than rock, cheaper, and easier to install. 1�laterials can be chosen using manufacturei-product specifications. ASTM test results are available for most products and the designer can choose the correct material for tlle expected flow. • With low flows, vegetation (including sod) can be effective. � • The following guidelines shall be used for riprap outlet protection: 1. If the discharge velocity at the outlet is less than 5 tps (pipe slope less than 1 percent), use 2-inch to 8-inch riprap. Minimum thickness is 1-foot. 2. For 5 to 10 fps discharge velocity at the outlet (pipe slope less than 3 percent), use 24-inch to 4-foot riprap. Minimum thickness is 2 feet. 3. For outlets at the base of steep slope pipes (pipe slape greater than 10 percent}, an engineered energy dissipater shall be used. • Filter fabric or erosian control blankets should always be used under riprap to prevent scour and channel erosion. • New pipe outfalls can provide an opporiunity foi- low-cost fish habitat improvements. For example, an alcove of low-velocity water can be created bv constructing the pipe outfall and associated energy dissipater back from the stream edge and digging a channel, over- widened a tJ2e upstrPea�m s�i�e�f�m the outfall. O��ervvintering juvenile and migr��d� s � ay use the alco��e as shelter during FOR ASBUILT 4-80 Volume I!— Construction Stormwater Pollution Prevention February 2005 high flows. Bank stabilization, bioengineering, and habitat features may be required for disturbed areas. See Volume V for more information on outfall system design. Maintenance . Inspect and repair as needed. Standards • Add rock as needed to maintain the intended function. • Clean energy dissipater if sediment builds up. NOT UPDATED FOR ASBUILT February 2005 Volume U- Ccnstruction Stormwater PoJlution Prevention 4-81 BMP C151: Concrete Handling Puipose Concrete work can generate process water and sluny that contain fine particles and high pH, both of which can violate water quality standards in the receiving water. This B'VIP is intended to minimize and eliminate concrete process water and slurry• from entering waters of the state. CondiNons of Use Any time concrete is used, these management practices shall be utilized. Concrete construction projects include, but are not limited to, the following: • Curbs • Sidewalks • Roads . Bridges • Foundations ' • Floors • Runwavs Desig� a�id • Concrete truck chutes, pumps, and internals shall be washed out only Installation into formed areas awaiting installation of coiicrete or asphalt. Specificatior:s Unused concrete remaining in the truck and pump shall be retut��ed to � the originating batch plant for recycling. • Hand tools incliiding, but not limited to, screeds, shovels, rakes, floats. and trowels shall be «�ashed off only into forn�ed areas awaitina installation of concrete or asphalt. y • Equipment that cannot be easily ntoved, stzch as concrete paver5, shall only be washed in areas that do not directly drain to natural or const►-ucted storm��ater conveyances. ' . �'t�ashdown from areas such as concrete aggregate driveways shall not drain directly to natural or constructed stoi7nwater conveya�ices. • V4'hen no formed areas are available, washwater and leftover product shall be contained in a lined container. Contained conerete shall be disposed of in a manner that doe� n��t �iolate �round«�ater or stirface water quality standar�l�. ,�Ylairrte�tanee Containers shall be eheckc�l t��r E�.>le� in tl�� iin�i dai!�� ciurn;t� c��n�rct� StlI1J[�lll'(�.S ;�t)l:i�� i,'l� ,�.��ili��C� l�l�' �:1;!l� t�:i\_ - - NOT UPDATED FOR ASBUILT - __ � n . F_P.�h��lc3ry 2�O,rj 1,/O{UmE ��— COl1SIlUCt7�^,f? SiOI"'r!l4'-rfp'�;� ,�1;;�, �"F t .. , '"1'� •. -t... BMP C152: Sawcutting and Surfacing Pollution Prevention Purpose Sawcutting and surfacing operations generate slurry and process water that contains fine particles and high pH (concrete cutting), both of�irhich can eiolate the water quality standards in the receiving water. This BMP is intended to minimize and eliininate process water and slurry from entering waters of the State. Conditions of L�se An}�time sawcutting or surfacing operations take place, these management practices shall be utilized. Sawcutting and surfacing operations include, but are not limited to, the following: • Sawing • Coring • Grinding • Roughening • Hvdro-demolition • Bridge and road surfacing Desig�t and • SIurry and cuttings shall be vacuumed during cutting and surfacing Ijistallution operations. Specificatio►�s Sluny and cuttings shall not remain on pennanent concrete or asphalt • pavement overnight. • Slurry and.cuttings shall not drain to any natural or constructed drainage conveyance. • Collected slurry and cuttings shall be disposed of in a manner that does not violate groundwater or surface wrater quality standards. • Process water that is generated during hydro-demolition; surface roughei�in� or similar operations shall not drain to any natural or constnicted drainage conveyance and shall be disposed of in a manner that does not violate groundwater or surface water qualiry standards. • Cleaning waste material and demolition debris shall be handled and disposed of in a manner that does not cause contami�iation of water. If the area is swept with a pick-up sweeper, the material must be hauled out of the area to an appropriate disposal site. Maintenarrce Continualiy monitor operations to detennine ��hether siurrv, cuttinas, or Standards process water could enter waters of the state. If inspections show that a , violation of water quality standards could occur, stop operations ancl '� immediately implement preventive measures such as hernl:. harrier�, ' secondary containment, and vacuum tn�cks. 'I NOT UPDATED � FOR ASBUILT j - --- ----- - -- _ -- - __ �-'`fti l��iJ11'6' ii - 1,,� ��r,:Cfl� � ��.. R-�.,%�?`E'' �G� . . ��1 �' c:=E'r(.�. FC _,�;31 v' � '�7F � Stormwater Pollution Prevention Plan Appendix C — Alternative BMPs The following includes a list of possible alternative BMPs for each of the 12 elements not described in the main SWPPP text. This list can be referenced in the event a BMP for a specific element is not functioning as designed and an alternative BMP needs to be implemented. Element No. 1 - Mark Clearing Limits BMP C 102: Buffer Zones BMP C 104: Stake and Wire Fence Element No. 2 - Establish Construction Access BMP C106: Wheel Wash BMP C 107: Construction RoadlParking Area Stabilization Element No. 3 - Control Flow Rates BMP C240: Sediment Trap Element No. 4 - Install Sediment Controls BMP C230: Straw Bale Barrier BMP C231: Brush Barrier BMP C232: Gravel Filter Berm BMP C234: Vegetated Strip BMP C235: Straw Wattles BMP C240: Sediment Trap Advanced BMPs: BMP C250: Construction Stormwater Chemical Treatment BMP C251: Construction Stormwater Filtration Element No. 5 - Stabilize Soils BMP C121: Mulching BMP C 124: Sodding BMP C 126: Polyacrylamide for Soil Erosion Protection BMP C 130: Surface Roughening BMP C 131: Gradient Terraces BMP C 180: Small Project Construction Stormwater Pollution Prevention �, Element No. 6 - Protect Slopes ��I BMP C120: Temporary and Permanent Seeding BMP C130: Surface Roughening BMP C131: Gradient Terraces BMP C205: Subsurface Drains BMP C206: Level Spreader BMP C207: Check Dams N OT U P DAT E D FOR ASBUILT 25 Stormwater Po!lution Prevention Plan Appendix D — General Permit NOT UPDATED FOR ASBUILT �� Stormwater Po!lution Prevention Plan Appendix E — Site Inspection Forms (and Site Log) The results of each inspection shall be summarized in an inspection report or checklist that is entered into or attached to the site log book. It is suggested that the inspection report or checklist be included in this appendix to keep monitoring and inspection information in one document, but this is optional. However, it is mandatory that this SWPPP and the site inspection forms be kept onsite at all times during construction, and that inspections be performed and documented as outlined below. At a minimum, each inspection report or checklist shall include: I, a. Inspection date/times ' b. Weather information: general conditions during inspection, ' approximate amount of precipitation since the last inspection, and approximate amount of precipitation within the last 24 hours. c. A summary or list of all BMPs that have been implemented, including observations of all erosion/sediment control structures or practices. d. The following shall be noted: i. locations of BMPs inspected, ii. locations of BMPs that need maintenance, iii. the reason maintenance is needed, iv. locations of BMPs that failed to operate as designed or intended, and v. locations where additional or different BMPs are needed, and the reason(s) why e. A description of stormwater discharged from the site. The presence of suspended sediment, turbid water, discoloration, and/or oil sheen shall be noted, as applicable. f. A description of any water quality monitoring performed during inspection, and the results of that monitoring. g. General comments and notes, including a brief description of any BMP repairs, maintenance or installations made as a result of the inspection. NOT UPDATED FOR ASBUILT 29 - Stormwafer PolJution Prevention Plan h. A statement that, in the judgment of the person conducting the site inspection, the site is either in compliance or out of compliance with the terms and conditions of the SWPPP and the NPDES permit. If the site inspection indicates that the site is out of compliance, the inspection report shall include a summary of the remedial actions required to bring the site back into compliance, as well as a schedule of implementation. i. Name, title, and signature of person conducting the site inspection; and the following statement: "I certify under penalty of law that this report is true, accurate, and complete, to the best of my knowledge and belief'. When the site inspection indicates that the site is not in compliance with any terms and conditions of the NPDES permit, the Permittee shall take immediate action(s) to: stop, contain, and clean up the unauthorized discharges, or otherwise stop the noncompliance; correct the problem(s); implement appropriate Best Management Practices (BMPs), and/or conduct maintenance of existing BMPs; and achieve compliance with all applicable standards and permit conditions. In addition, if the noncompliance causes a threat to human health or the environment, the Permittee shall comply with the Noncompliance Notification requirements in Special Condition SS.F of the permit. NOT UPDATED FOR ASBUILT �o Stormwater Pollution Prevention Plan Site Inspection Form General Information 1� Project Name: �_ Inspector Name: Title: CESCL # : ' � Date: Time: Inspection Type: � After a rain event ❑ Weekly ❑ Turbidity/transparency benchmark exceedance ❑ Other Weather : ; Precipitation Since last inspection In last 24 hours Description of General Site Conditions: Inspection of BMPs Element 1: Mark Clearing Limits BMP: � Location Inspected Functioning problem/Corrective Action Y N Y N NIP BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP Element 2: Establish Construction Access BMP: Location �spected Functioning problem/Corrective Action Y N Y N NIP BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP NO ED FO ILT �� Stormwater Pollutron Prevention Plan Element 3: Control Flow Rates BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP r-� BMP: -� Location Inspected Functioning problem/Corrective Action Y N Y N NIP '�� Element 4: Install Sediment Controls �_ � BNtP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP � BMP: Location �spected Functioning problem/Corrective Action Y N Y N NIP � BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP - BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP � BMP: Location �spected Functioning problem/Corrective Action Y N Y N NIP ' h NO ED FOR ASBUILT �� Stormwater Pollution Prevention Plan Element 5: Stabilize Soils BMP: `_� Location Inspected Functioning problem/Corrective Action � Y N Y N NIP '_1 � BMP: - Location Inspected Functioning problem/Corrective Action Y N Y N NIP __� ; l BMP: `-� Inspected Functioning Location Y N Y N NIP Problem/Corrective Action BMP: Location �spected Functioning problem/Corrective Action Y N Y N NIP ' Element 6: Protect Slopes BMP: Location Inspected Functioning problem/Corrective Action - Y N Y N NIP : � BMP: Location Inspected Functioning problen�/Corrective Action Y N Y N NIP �; BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP � NO ED FOR ASBUILT �� Stormwater Pollution Prevention Plan Element 7: Protect Drain Inlets BMP: Location �spected Functioning problem/Corrective Action Y N Y N NIP �- � �. BMP: '- � Location �spected Functioning problem/Corrective Action Y N Y N NIP J �` � BMP: Location Inspected Functioning problem/Corrective Action ,__� Y N Y N NIP `, _J Element 8: Stabilize Channels and Outlets BMP: Location �spected Functioning problem/Corrective Action Y N Y N NIP BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP � � � BMP: Location �spected Functioning problem/Corrective Action Y N Y N NIP �. BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP � i } NO ED FOR ASBUILT �� Stormwater Pollution Prevention Plan Element 9: Control Pollutants BMP: Location Inspected Functioning problem/Conective Action Y N Y N NIP �� BMP: - ' Location Inspected Functioning problem/Corrective Action Y N Y N NIP �_ J � Element 10: Control Dewatering BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP � BMP: Location Inspected Functioning problem/Corrective Action � Y N Y N NIP BMP: Location Inspected Functioning problem/Corrective Action Y N Y N NIP Stormwater Dischar es From the Site Observed? problem/Corrective Action Y �N Location Turbidity Discoloration Sheen Location Turbidity Discoloration Sheen FOR ASBUILT 35 Stormwater Pollution Prevention Plan Water Quality Monitorin Was any water quality monitoring conducted? o Yes ❑ No If water quality monitoring was conducted,record results here: If water quality monitoring indicated turbidity 250 NTU or greater; or transparency 6 cm or less, was Ecology notified by phone within 24 hrs? ❑ Yes ❑ No If Ecology was notified, indicate the date, time, contact name and phone number below: Date: Time: Contact Name: Phone#: General Comments and Notes Include BMP re airs, maintenance, or installations made as a result of the ins ection. � Were Photos Taken? ❑ Yes ❑ No If hotos taken, describe hotos below: NOT UPDATED FOR ASBUILT �� Stormwater Pollution Prevention Plan Appendix F - Engineering Calculations NOT UPDATED FOR ASBUILT �� p�o,ect �� ` �Ot M� by s�eei cc • ConsultrngEngineers '/Ze ,� roca6on T date ?6G1 Sth Avenue,Suite 1600 job no Seattle, WA 98101 coent ��'� (206)622-5822 Fax{206)622-8130 SE'D t t�'1 �'NT'' T�o N b 51 Z��v 4 S� = Z C Qi 15•MIN� 1'T� D'T? ��'S�ItJD�) o, ono 9G ,S� = Z �.��+7 ��5 = I,q73 SF a, o0 o'tG TL -�-� 3.5� D�� 3:I S� D�s .�- D 3:� r�, :T� 8L 8w j3� = -t—�— 21 8t�,� = Tc� — Z I �}��) z t973 'r � f� = 3 � 3 TW L� 1� 7 3 C � r w= 25.� �.= ��•q, 8 w= �+,`S, 8�= 55,q � _ �t _ Z .` + , ?� +- s , 4 5 �°� 3S Z,,, 2 , � � „ S23 � NOT UPDATED FOR ASBUILT k ff Appendix E City of Renton Documents Vantage Point Apartments Technical Information Report Appendix E Site Improvement Bond Quantity Worksheet Original bond computations prepared by: Name: CHRISTOPHER BORZIO �ate: 1/27/2014 PE Registration Number: WA 48787 Tel.#: (206)926-0418 Firm Name: KPFF CONSULTING ENGINEERS Address: 1601 FIFTH AVE STE 1600 SEATTLE WA 98101 Project No: ROAD IMPROVEMENTS&DRAINAGE FACILITIES FINANCIAL GUARANTEE REQUIREMENTS PERFORMANCE BOND','" PUBLIC ROAD 8 DRAINAGE AMOUNT MAINTENANCE/DEFECT BOND'," Stabilization/Erosion Sediment Control(ESC) (A) $ 15,896J Existing Right-of-Way Improvements (B) $ 68,885.8 Future Public Road Improvements& Drainage Facilities (C) $ - Private Improvements (D) $ 579,575.9 Construction Bond'Amount (A+B+C+D) = TOTAL (T) $ 664,358.4 Minimum bond'amount is$1000. (B+C)x Maintenance/Defect Bond`Total 0.20= $ 13,777.2 NAME OF PERSON PREPARING BOND'REDUCTION: Date: 'NOTE: The word"bond"as used in this document means any financial guarantee acceptable to the City of Renton. "NO7E: qll prices include labor,equipment,materials,overhead and profit. Prices are from RS Means data adjusted for the Seattle area or from local sources if not included in the RS Means database. REQUIRED BOND'AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY RDSD N OT U P DATE D Page1 of7 FOR ASBUILT Unitpricesupdated:2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/31/2014 Site Improvement Bond Quantity Worksheet Existing Future Public Private Quantity Completed Right-of-Way Road Improvements Improvements (Bond Reduction)` &Drainage Facilities Quant. nit rice nit uant. ost uani osl uant. ost Complete Cost GENERAL ITEMS No. Backfill&Compaction-embankment GI - 1 $ 5.62 CY 0.00 0.00 0.00 0.00 Backfill&Compaction-trench GI-2 $ 8.53 CY 69 588.57 0.00 1201 10,244.53 0.00 Clear/Remove Brush,by hand GI-3 $ 0.36 SY 0.00 0.00 0.00 0.00 Clearing/Grubbing/Tree Removal GI-4 $ 8,876.16 Acre 0.3 2,662.85 0.00 2.7 23,965.63 0.00 Excavation-bulk GI-5 $ 1.50 CY 0.00 0.00 20052 30,078.00 0.00 Excavation-Trench GI-6 $ 4.06 CY 69 280.14 0.00 1201 4,876.06 0.00 Fencing,cedar,6'high GI-7 $ 18.55 LF 0.00 0.00 0.00 0.00 Fencing,chain link,vinyl coated, 6'high GI-8 $ 13.44 LF 0.00 0.00 572 7,687.68 0.00 Fencing,chain link,gate,vinyl coated, 2 GI-9 $ 1,271.81 Each 0.00 0.00 4 5,087.24 0.00 Fencing,split rail,3'high GI- 1 $ 12.12 �F 0.00 0.00 162 1,963.44 0.00 i Fill&compact-common barrow GI- 11 $ 22.57 CY 0.00 0.00 1086 24,511.02 0.00 Fill&compact-gravel base GI- 1 $ 25.48 CY 0.00 0.00 0.00 0.00 Fill&compact-screened topsoil GI- 1 $ 37.85 CY 0.00 0.00 0.00 0.00 Gabion, 12"deep,stone filled mesh GI-1 $ 54.31 SY 0.00 0.00 0.00 0.00 Gabion, 18"deep,stone filled mesh GI-1 $ 74.85 SY 0.00 0.00 0.00 0.00 Gabion,36"deep,stone filled mesh GI-1 $ 132.48 SY 0.00 0.00 0.00 0.00 Grading,fine,by hand GI-1 $ 2.02 SY 0.00 0.00 1460 2,949.20 0.00 Grading,fine,with grader GI-1 $ 0.95 SY 0.00 0.00 13149 12,491.55 0.00 Monuments,3'long GI-1 $ 135.13 Each 0.00 0.00 0.00 0.00 Sensitive Areas Sign GI-2 $ 2.88 Each 0.00 0.00 0.00 0.00 Sodding, 1"deep,sloped ground GI-21 $ 7.46 SY 0.00 0.00 0.00 0.00 Surveying,line&grade GI-2 $ 788.26 Day 1 788.26 0.00 30 23,647.80 0.00 Surveying,lot location/lines GI-2 $ 1,556.64 Acre 0.00 0.00 3 4,669.92 0.00 Traffic control crew(2 flaggers) GI-2 $ 85.18 HR 120 10,221.60 0.00 0.00 0.00 Trail,4"chipped wood GI-2 $ 7.59 SY 0.00 0.00 0.00 0.00 Trail,4"crushed cinder GI-2 $ 8.33 SY 0.00 0.00 0.00 0.00 Trail,4"top course GI-2 $ 8.19 SY 0.00 0.00 0.00 0.00 Wall,retaining,concrete GI-2 $ 44.16 SF 0.00 0.00 0.00 0.00 a ,roc ery -2 9.49 0.00 0.00 0.00 0.00 Page 2 of 7 SUBTOTAL 14,541.42 0.00 152,172.07 0.00 NOT UPDATED F O R AS B U I LT Unit prices updated:2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/31/2014 Site Improvement Bond Quantity Worksheet Existing Future Public Private Bond Reduction' Right-of-way Hoad Improvements Improvements &Drainage Facilities Quant. nit nce nit uant. ost uant ost uant. ost Complete Cost ROADIMPROVEMENT No. AC Grinding,4'wide machine< t000sy RI- 1 $ 23.00 SY 0.00 0.00 0.00 0.00 AC Grinding,4'wide machine 1000-2000 RI-2 $ 5J5 SY 0.00 0.00 0.00 0.00 AC Grinding,4'wide machine>2000sy RI-3 $ 1.38 SY 0.00 0.00 0.00 0.00 AC Removal/Disposal/Repair RI-4 $ 41.14 SY 137 5,636.18 0.00 0.00 0.00 Barricade,type I RI-5 $ 30.03 LF 0.00 0.00 0.00 0.00 Barricade,type III(Permanent) RI-6 $ 45.05 LF 0.00 0.00 0.00 0.00 Curb&Gutter,rolled RI-7 $ 13.27 LF 0.00 0.00 0.00 0.00 Curb&Gutter,vertical RI-8 $ 9.69 LF 140 1,356.60 0.00 1410 13,662.90 0.00 Curb and Gutter,demolition and disposal RI-9 $ 13.58 LF 140 1,901.20 0.00 0.00 0.00 Curb,extruded asphalt RI- 1 $ 2.44 LF 0.00 0.00 0.00 0.00 Curb,extruded concrete RI- 11 $ 2.56 LF 0.00 0.00 0.00 0.00 Sawcut,asphalt,3"depth RI- 1 $ 1.85 LF 395 730.75 0.00 0.00 0.00 Sawcut,concrete,per 1"depth RI- 1 $ 1.69 LF 0.00 0.00 0.00 0.00 Sealant,asphalt RI- 1 $ 0.99 LF 0.00 0.00 0.00 0.00 Shoulder,AC, (see AC road unit price) RI- 1 $ - SY 0.00 0.00 0.00 0.00 Shoulder,gravel,4"thick RI-1 $ 7.53 SY 0.00 0.00 0.00 0.00 Sidewalk,4"thick RI-1 $ 30.52 SY 587 17,915.24 0.00 2056 62,749.12 0.00 Sidewalk,4"thick,demolition and dispos RI-1 $ 27.73 SY 0.00 0.00 0.00 0.00 Sidewalk,5"thick RI-1 $ 34.94 SY 0.00 0.00 0.00 0.00 Sidewalk,5°thick,demolition and dispos RI-2 $ 34.65 SY 0.00 0.00 0.00 0.00 I Sign, handicap RI-21 $ 85.28 Each 0.00 0.00 0.00 0.00 ' Striping,per stall RI-2 $ 5.82 Each 0.00 0.00 27 157.14 0.00 � Striping,thermoplastic,(for crosswalk) RI-2 $ 2.38 SF 0.00 0.00 0.00 0.00 triping,4"re lectorize ine -2 0.25 0.00 0.00 0.00 0.00 Page 3 of 7 SUBTOTAL 27,539.97 0.00 76,569.16 0.00 I NOT UPDATED F O R AS B U I LT Unit prices updated:2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: t/31/2014 Site Improvement Bond Quantity Worksheet Existing Future Public Private Bond Reduction' Right-of-way Road Improvements Improvements &Drainage Facilities �uant. nit rice nit uant. ost uant ost uant. ost Complete Cost For KCRS'93,(additional 2.5"base)add RS- 1 $ 3.60 SY 0.00 0.00 0.00 0.00 i AC Overlay, 1.5"AC RS-2 $ 7.39 SY 0.00 0.00 0.00 0.00 AC Overlay,2"AC RS-3 $ 8.75 SY 0.00 0.00 0.00 0.00 AC Road,2",4"rock,First 2500 SY RS-4 $ 17.24 SY 0.00 0.00 0.00 0.00 AC Road,2",4"rock,Qty.over 2500SY RS-5 $ 13.36 SY 0.00 0.00 0.00 0.00 AC Road,3",4"rock, First 2500 SY RS-6 $ 19.69 5Y 137 2,697.53 0.00 2500 49,225.00 0.00 AC Road,3",4"rock,Qty.over 2500 SY AS-7 $ 15.81 SY 0.00 0.00 303 4,790.43 0.00 AC Road,5",First 2500 SY RS-8 $ 14.57 SY 0.00 0.00 0.00 0.00 AC Road,5",Qty.Over 2500 SY RS-9 $ 13.94 SY 0.00 0.00 0.00 0.00 AC Road,6",First 2500 SY S-1 $ 16.76 SY 0.00 0.00 0.00 0.00 AC Road,6",�ty.Over 2500 SY S-1 $ 16.12 SY 0.00 0.00 0.00 0.00 Asphalt Treated Base,4"thick S-1 $ 9.21 SY 0.00 0.00 0.00 0.00 Gravel Road,4"rock, First 2500 SY S-1 $ 11.41 SY 0.00 0.00 0.00 0.00 Gravel Road,4"rock,Qty.over 2500 SY S-1 $ 7.53 SY 0.00 0.00 0.00 0.00 PCC Road,5",no base,over 2500 SY S- i $ 21.51 SY 0.00 0.00 0.00 0.00 PCC Road, 6",no base,over 2500 SY S- 1 $ 21.87 SY 0.00 0.00 0.00 0.00 ic ene ge - 1 6.8 0.00 0.00 0.00 Page 4 of 7 SUBTOTAL 2,697.53 0.00 54,015.43 0.00 NOT UPDATED FOR ASBU I LT Unit prices updated:2/12/02 � Version:4/22/02 I REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/31/2014 ��i --- I Site Improvement Bond Quantity Worksheet Existing Future Public Private Bond Reduction' Right-of-way Road Improvements Improvements &Drainage Facilities Quant. nit nce nit uant. ost uant ost uant. ost Complete Cost _ For CuNert prices, Average of 4'cover was assumed.Assume perforated PVC is same price as solid pipe. Access Road, R/D D- 1 $ 16.74 SY 0.00 0.00 0.00 0.00 Bollards-fixed D-2 $ 240.74 Each 0.00 0.00 0.00 0.00 Bollards-removable D-3 $ 452.34 Each 0.00 0.00 0.00 0.00 `(CBs include frame and lid) CB Type I D-4 $ 1,257.64 Each 0.00 0.00 17 21,379.88 0.00 CB Type IL D-5 $ 1,433.59 Each 0.00 0.00 0.00 0.00 CB Type II,48"diameter D-6 $ 2,033.57 Each 2 4,067.14 0.00 2 4,067.14 0.00 for additional depth over 4' D-7 $ 436.52 FT 6 2,619.12 0.00 2 873.04 0.00 C8 Type II,54"diameter D-8 $ 2,192.54 Each 0.00 0.00 0.00 0.00 for additional depth over 4' D-9 $ 486.53 FT 0.00 0.00 0.00 0.00 CB Type II,60"diameter D- 10 $ 2,351.52 Each 0.00 0.00 0.00 0.00 for additional depth over 4' D- 11 $ 536.54 FT 0.00 0.00 0.00 0.00 CB Type II,72"diameter D- 12 $ 3,212.64 Each 0.00 0.00 0.00 0.00 for additional depth over 4' D- 13 $ 692.21 FT 0.00 0.00 0.00 0.00 Through-curb Inlet Framework(Add) D- 14 $ 366.09 Each 0.00 0.00 0.00 0.00 Cleanout, PVC,4" D- 15 $ 130.55 Each 0.00 0.00 0.00 0.00 Cleanout, PVC,6" D- 16 $ 174.90 Each 0.00 0.00 9 1,574.10 0.00 Cleanout, PVC,8" D- 17 $ 224.19 Each 0.00 0.00 16 3,587.04 0.00 Culvert, PVC,4" D- 18 $ 8.64 LF 0.00 0.00 0.00 0.00 Culvert, PVC,6" D-19 $ 12.60 LF 0.00 0.00 353 4,447.80 0.00 Culvert, PVC, 8" D-20 $ 13.33 LF 0.00 0.00 1390 18,528.70 0.00 Culvert, PVC, 12" D-21 $ 21.77 LF 70 1,523.90 0.00 739 16,088.03 0.00 Culvert,CMP,S" D-22 $ 17.25 LF 0.00 0.00 0.00 0.00 Culvert,CMP, 12" D-23 $ 26.45 LF 0.00 0.00 0.00 0.00 Culvert,CMP, 15" D-24 $ 32.73 LF 0.00 0.00 0.00 0.00 Culvert,CMP, 18" D-25 $ 37J4 LF 0.00 0.00 0.00 0.00 Culvert,CMP,24" D-26 $ 53.33 LF 0.00 0.00 0.00 0.00 Culvert,CMP,30" D-27 $ 71.45 LF 0.00 0.00 0.00 0.00 Culvert,CMP,36" D-28 $ 112.11 LF 0.00 0.00 0.00 0.00 Culvert,CMP,48" D-29 $ 140.83 LF 0.00 0.00 0.00 0.00 Culvert,CMP,60" D-30 $ 235.45 LF 0.00 0.00 0.00 0.00 u vert, ,72" -31 302.58 0.00 0.00 0.00 0.00 Page 5 of 7 SUBTOTAL 8,210.16 0.00 70,545.73 0.00 I NOT UPDATED FOR ASBU I LT Unit prices updated:2/12/02 Version:4/22/02 i REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: i/31/2014 Site Improvement Bond Quantity Worksheet Existing Future Public Private Bond Reduction' Right-of-way Road Improvements Improvements DRAINAGE CONTINUED &Drainage Facitities Quant. o. nit rice rnt uant. ost uant ost uant. ost Complete Cost Culvert.Concrete,8" -32 21.02 0 0 0 0 Culvert,Concretc, 12" D-33 $ 30.05 LF 0 0 0 0 Culvert,Concrete,15" D-34 $ 37.34 LF 0 0 0 0 Culvert,Concrete, 18" D-35 $ 44.51 LF 0 0 0 0 Culvert,Concrete,24" D-36 $ 61.07 LF 0 0 0 0 Culvert,Concrete,30" D-37 $ 104.1 S LF 0 0 0 0 Culvert,Concrete,36" D-38 $ 137.63 LF 0 0 0 0 Culvert,Concrete,42" D-39 $ 158.42 LF 0 0 0 0 Culvert,Concrete,48" D-40 $ 175.94 LF 0 0 0 0 Culvert,CPP,6" D-41 $ 10.70 LF 0 0 0 0 Culvert,CPP,8" D-42 $ 16.10 LF 0 0 0 0 Culvert,CPP, 12" D-43 $ 20.70 LF 0 0 0 0 Culvert,CPP, 15" D-44 $ 23.00 LF 0 0 0 0 Culvert,CPP, 18" D-45 $ 27.60 LF 0 0 0 0 Culvert,CPP,24" D-46 $ 36.80 LF 0 0 0 0 Culvert,CPP,30" D-47 $ 48.30 LF 0 0 0 0 Culvert,CPP,36" D-48 $ 55.20 LF 0 0 0 0 Ditching D-49 $ 8.08 CY 0 0 0 0 Flow Dispersal Trench (1,436 base+) D-50 $ 25.99 LF French Drain (3'depth) D-51 $ 22.60 LF 0 0 0 0 Geotextile,laid in trench,polypropylene D-52 $ 2.40 SY 0 0 0 0 In(iltration pond testing D-53 $ 74.75 HR 0 0 0 0 Mid-tank Access Riser,48"dia, 6'deep D-54 $ 1,605.40 Each 0 0 0 0 Pond Overflow Spillway D-55 $ 14.01 SY 0 0 0 0 Restrictor/Oil Separator, 12" D-56 $ 1,045.19 Each 0 0 1 1045.19 0 Restrictor/Oil Separator, 15" D-57 $ 1,095.56 Each 0 0 0 0 Restrictor/Oil Separator, 18" D-58 $ 1,146.16 Each 0 0 0 0 Riprap,placed D-59 $ 39.08 CY 0 0 0 0 Tank End Reducer(36"diameter) D-60 $ 1,000.50 Each 0 0 0 0 Trash Rack, 12" D-61 $ 211.97 Each 0 0 0 0 Trash Rack, 15" D-62 $ 237.27 Each 0 0 0 0 Trash Rack, 18" D-63 $ 268.89 Each 0 0 0 0 ras ac ,21" -64 306.84 ach 0 0 0 0 Page 6 of 7 SUBTOTAL 0 0 1045.19 0 NOT UPDATED F O R AS B U I LT Unit prices updated:2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/31/2014 Site Improvement Bond Quantity Worksheet Existing Future Public Private Bond Reduction' Right-of-way Road Improvements Improvements &Drainage Facilities Quant. rnt nce nit uant. rice uant ost uant. ost Complete Cost PARKIN LOT SURFACING No. I 2"AC,2"top course rock&4"borrow PL-1 $ 15.84 SY 0 0 0 0 2"AC, 1.5" top course&2.5"base cour PL-2 $ 17.24 SY 0 0 0 0 I 4"select borrow PL-3 $ 4.55 SY 0 0 0 0 1.5"top course rock&2.5"base course PL-4 $ 11.41 SY 0 0 0 0 W - EMS (Such as detention/water quality vaults.) No. W I- 1 0 0.00 0.00 0.00 W I-2 0 0.00 0.00 0.00 AREA DRAIN W I-3 $ 500.00 Each 0 0.00 13 6,500.00 0.00 TRENCH DRAIN W I-4 $ 5,000.00 Each 0 0.00 4 20,000.00 0.00 GRASSCRETE WI-5 $ 50.00 SY 0 0.00 839 41,950.00 0.00 PERVIOUS PAVEMENT W I-6 $ 35.00 5Y 0 0.00 658 23,030.00 0.00 W I-7 0 0.00 0.00 0.00 W I-8 0 0.00 0.00 0.00 W I-9 0 0.00 0.00 0.00 wi-io 0.00 0.00 0. 5 U BTOTAL 0.00 0.00 91,480.00 0.00 SUBTOTAL(SUM ALL PAGES): 52,989.08 0.00 445,827.58 0.00 30%CONTINGENCY&MOBILIZATION: 15,896.72 0.00 133,748.27 0.00 GRANDTOTAL: 68,885.80 0.00 579,575.86 0.00 COLUMN: B C D E Page 7 of 7 NOT UPDATED FOR ASBU I LT Unit prices updated:2/12/02 Version:4/22/02 REF 8-H BOND QUANTITY WORKSHEET.xIs Report Date: 1/31/2014 --��.+�'��T,,; ��f i 1ZL-COIZDWG Rl�:(�L.�LSTI�.f) �3Y r�NU WHEN RECORDED ��i:AiL "1�0: CITY CLERK'S OFFICI�: CITY OR RENTON 1055 SOUTH GRADY WAY RE�ITON, WA 98057 DECLARATION OF COVENANT FOR INSPECTION AND MAINTENAICE OF STORM�'A"I'ER FACILITIES A:�1D B1��1PS �irai�tur: Grantee: City or Rcu;��n Legal Description: Additional Legal(s)on: Asscssor's Z�ax Parcel IDi-: IV CONSIDER.ATION of the approved City or Renton___ _ permit for application file No. LL'A/SV�'P relating to the real property ("Propert}") described above, the Grantor(s), the owner(s) in fee of that Property, hereby covenants(co��enant) with thc City ��r Rentr.n, a politicai subdi��ision of the state �,f��'a;hir.gton, that nc�she(theyl �.vill �>bserve, consent to, and abide by the conditions and obligations set forth and described in Paragraphs 1 th��-�u�r 1(1 Le:�_>�.v ��vith �cgard :o t:�e P:n��,rt�-. and her�by �rant�(�ra�:tj an ea�e:nent a; d"cril�c� in �FtICi�:'�i��]< < 3:1�� i. ��C.1RlOt(�) �-i�iC��ti' "I��:Ilt�(�11-�:Ilt1, COA'C?i311I�(:O�'<Il:ilil). dtlC� H�'I'�ci1,1:�ZI'CC) �:� �0.�(".�'�: ]. 'The Grantor(s) or his/her(their) successors in interest and assigns ("OwZ�ers") shall at their ��«n c��t. c�peratc, main!.iin, and keep in good repair, the Property's stormwater facilities and best ,»;�;la��;;��,t �r,l,::c;:. �''[3MPs") identified in the plans and specifications submitted to King County for thc review and approval of permit(s) #: . Stormwater facilities :r.c;::G� �>>->��, ,��ales, tanks, vaults, ponds, and other engineered structures designed to inanage ��m��,�a;c- on the Property. Stormwater BMPs include dispersion and infiltration devices, native �e��etated areas, penneable pavements, vegetated roofs, rainwater harvesting systems, reduced impet-�-ious ;tu face coverage, and other measures designed to reduce the amount of stormwater runoff on the Pro�erty. �. City or Renton shall have the right to ingress and egress over those portions of the Property necessary to perform inspections of the stormwater facilities and BMPs and conduct other activities �pecified in this Declaration of Covenant and in accordance with RMS 4-6-030. This right of ingress and ::��ress, right to inspect, and r�ght to perform required maintenance or repair as provided for in Section 3 !�:':o�.�.�. ;hall not extend over those portions of the Property shown in Exhibit "A." : �. lf City of Renton determines that maintenance or repair work is required to be done to any of th� �cc�:m�vater facilities or B�fPs, City of Renton shall give notice oFthe specific maintenance and/or repa�r«,�ork required pursuant to RMC 4-6-030. The City shall also set a reasonable time in which such �,�:ork is to be completed by the Owners. If the above required maintenance or repair is not completed �vithin the time set by the City, the City may perfotm the required maintenance or repair, and hereby is given access to the Property, subject to the exclusion in Paragraph 2 above, for such purposes. l��'ritten notice will be sent to the O�;mers stating the City's intention to perform such work. This work will not commence until at least seven(7) days after such notice is mailed. If, within the sole discretion of the City, there exists an imminent or present danger; the seven {?) day iiotice period v��ill be ��•aived and �i maintenance and/or repair work will begin immediately. 4. If at any time the City of Renton reasonably determines that a stormwater facility or BMP on the Property creates any of the hazardous conditions listed in KCC 9.04.130 or relevant municipal successor's codes as applicable and herein incorporated by reference, The City may take measures specified therein. �. The Owners shall assume all responsibility for the cost of any maintenance or repair work completed by the City as described in Paragraph 3 or any measures taken by the County to address hazardous conditions as described in Paragraph 4. Such responsibility shall include reimbursement to the County within thirty (30) days of the receipt of the invoice for any such ��ork perfonned. Overdue payments will require payment of interest at the current legal rate as liquidated damages. If legal action ensues, the prevailing party is entitled to costs or fees. 6. The Owners are hereby required to obtain written approval from City of Renton prior to filliug, pipirig, cutting, or removing vegetation(except in routine landscape maintenance)in open �ebetated stormwater facilities (such as swales,channels,ditches,ponds, etc.), or perfonning any alterations or modifications to the stormwater facilities and BMPs referenced in this Declaration of C�>�enant. ,. Any notice or consent required to be given or otherwise provided for by the provisions of this .-��;reement shall be effective upon personal delivery, or three(3) days at�er mailing by Certified Mail, rctui-n rcceipt requested. �. With regard to the matters addressed herein, this agreement constitutes the entire agreement bct�4ecn the parties, and supersedes all prior discussions, negotiations, and all agreements whatsoever ��hether oral or written. ��. This Declaration of Covenant is intended to protect the value and desirability of the real property dcscribed above, and shall inure to the benefit of all the citizens of the Ciry of Renton and its succe.sors and assigns. This Declaratioii of Covenant shall run with the land and be binding upon Grantor(s), and Grantor's(s'} successars in interest, and assigns. ; � '0 �li;i� Dectaraiio3� of Cc��nant ma•�� be ��rminate� by� cxecut:o.� of a ��ri?ier- 3�_�iccment by the � U��ners and th� City ;hut �� recotdcd L}' Ki�l� �,�u.�ty i:h :t� r�al �,.��p�rt�� .e�ord� IN �� II�',�FSS WHEREOF,tl�is Declaration of Covenant for the Inspection and Maintenance of Storm��ater Fa;:i;i;i;:s al�d I3'�1P� i� executed t'.i:s �a�, of ?0 -- -_ _- - , GR.-��"1 UR ��.��tte: oi �ite P�_o�ert�� C�R%�\I(�R ��,�,�nea � �tlle Pr<�p��,� STATE OF WASHING70N ) COUNTY OF KING )ss. On this day personally appeared betore me: � � , to me I�lo«-u to 'ac t�.e indi��id..ai(�j de�cribed in �� and v��ho executed the within and foregoing instnin�ent and acknowledged tl:�at they si�,�ed t:�:e �a.l�e a: - their free and voluntary act and deed, for the uses and purposes therein stated. Given unc�'er�,�� 17and and�ftii:i�.l seal tiiis dav �f �0 __ Pcinted uamc �_ ' I��otary P�il��ll�� ;n �.. � .�r the 5ta?e r�f��a;hiz:_?t��,,. ,e;ic'.�^," ,,c �1y appoinUn��l? e�p�ce; � �� ,LL� i � ��J��ri . RECORDINC'i REQUESTED BY AND WHEN RECORDED MAIL TO: CITY CLERK'S OFFICE CITY OF RE'.�1TON 1055 SOUTH GRADY WAY � RENTON, WA 98057 DECLARATIOI�' OF COVENANT FOR MAINTEl\'A:VCE AND INSPECTION OF FLO�'V CONTROL BMPS Grantor: Grantee: City of Renton Legal Description: Additional Legal(s)on: Assessor's Tax Parcel ID#: II`CONSIDERATION of the approved City of Renton(check one of the following) 0 residential building permit, ❑ commercial building perniit, ❑ clearing and grading permit, ❑ subdivision permit, or ❑ short subdivision permit for Application File I�`o. LUA/SWP relating to the real property("Property") described above,the Grantor(s),the owner(s) in fee of that Property, hereby co��;nai.ts(cc��c:�antj «�itf�. C:ty or Rcnt<�n. ,1 �olit:cal �ubcii��i�iu�� of tlle �t,itc ��f��a�l�,i��ct��.�. that 1�c;'she�they)will observe, consent to, and abide by the conditions and obligations set forth and described :n Paragraphs 1 through 8 below with regard to the Property. Grantor(s) hereby grants(grant), co��nar.ts(covenant), and agrees(agree} as follows: 1. Grantor(s) or hislher(their) successors in interest and assigns ("Owners") shall retain, uphold, ar:�i �rotcct the stormwater management devices, features, pathways, limits, and restrictions, known as f,:o�ti control best management practices ("BMPs"l, shown on the approved Flow Control BMP Site Plan for the Property attached hereto and incorporated herein as Exhibit A. 2. The Owners shall at their own cost, operate,maintain, and keep in good repair, the Property's l�;vlPs as described in the approved Design and Maintenanc.e Details for each BMP attached hereto and :ncorporated hercin as Exhibit B. 3. City or Renton shall provide at least 30 days written notice to the Owners that entry on the Properry is planned for the inspection of the BMPs. After the 30 days, the Owners shall allow the City of Rc;:ton to e��tei for thc sole purpose of inspecting the BMPs. In lieu of inspection by the City, the C)��.�i��rr� m�:�� Icc- to en��:��_e a licensed eivil engineer registered in the state of Washington ��rho has cxpertise in drainage to inspect the BMPs and provide a written report describing their condition. If the en�i�leer option i� cliose►1, the 0��lei�s shall pr�vide v.�ritten notice to the City of Renton «�ithin tift�c�l d.ivs of:ecci��ing tl;e City'; notice of itlspect�on. �\ ;th�❑ 30 davs c�.`gi�it�� tt�is n��tice. th� O��ner�. ;�r tl�� ;:ngineer on behalf of the O�vners, shall provide the engineer's report to the City of Renton. If the report '.� .. , jl'1i lll�.!� 1' „ 1.'l "..;1 i: . „ ��`t:'.�:.(: :1f`i ... ��IC �0..�. '� 1' III� .. �f , f>�� `.\'.( . '.l; 'lJ l:._. ��;lh�:. 4 ff the City determines from its inspection, or from an engineer's report provided in accordance .�.��h f'ara`�:aph 3, that maintenance, repair, restoration, and�or mitigation work is required for the B'.vlPs, The City shall notify the Owners of the specific maintenance, repair,restoration, and%or mitigation work i 1',��k I r��yuired under RN1C 4-6-030. The City shall also set a reasonable deadline for completing the �V��.,rh ��r �r.��id:r:« sn �nrineer'; rc��rt :hat ��erifies con,pletioi: ��f the �'��ot�k 1fte-the de.;dLr,: ha� passed, the Owners shall allow the City access to re-inspect the BMPs unless an engineer's report has been provided verifying completion of the Work. If the work is not completed properly within the time frame set by the City, the Ciry may initiate an enforcement action. Failure to properly maintain the BMPs is a violation of RMC 4-6-030 and may subject the Owners to enforcement under the RMC 1-3, including fines and penalties. 5. Apart from performing routine landscape maintenance, the Owners are hereby required to obtain written approval from the City or Renton before performing any alterations or modifications to the I3'�1 P,. 6. An�; notice or:�p��ro��l required to be given by one party to the other under the provisions of thi5 Ueclaration of Covenant shall be effective upon personal delivery to the other party, or after three (3) cla�5 from the date that the notice or approval is mailed with delivery confirmation to the current address o;� recorcj with each Party. The parties shall notify each other of any change to their addresses. ?. Tl�is Declaration of Covenailt is intended to promote the efficient and effective management of �urface ��ater drainage on the Property, and it shall inure to the benefit of all the citizens of the City of Kc�,ton and its successors and assigns. This Declaration of Covenant shail run with the land and be hinciing upon Grantor(s), and Grantor's(s') successors in interest and assigns. R. This Declaration of Covenant may be terminated by execution of a written agreement by the Ch�i�ers and the City of Renton that is recorded hy King Counn� in its real pmperty records. I\WITNESS WHEREOF, this Declaration of Covenant for the Maintenance and Inspection of Flow Control BMPs is executed this day of , 20 GRA\TOR, ow�ner of the Property GRANTOR, owner of the Property STATE OF WASHINGTO'.� ) COUNTY OF KING )ss. On this day personally appeared before me: , to me kno�tim to be the individual(sj described in and who executed the within and foregoing instrument and acknowledged that they signed the same as their free and voluntary act and deed; for the uses and purposes therein stated. Given under my hand and official seal this__day of __, 20 Printed name Notary Public in and for the State of VVashington, I residing at ti1y appointment expires ,. I ; � : i _��_��; . RECORDP�IG REQL'ESTED BY AND WHE:v RECORDED MAIL TO: I CITY CLERK'S OFFICE CITY OF RENTON 1055 SOLTH GRADY VI�AY � RENTON WA 98057 DECLARATION OF COVENANT FOR IMPERVIOUS SURFACE LIiV1IT Grantor: Grantee: City of Renton Lzgal Description: Additional Legal(s) on: ��,�cssor's 7�ax Parcel II��: I\ ('O'�SII)ER.�TION uf�tl�c apE,ru��c�l Cit�� of Rcnton _ }��r��it i��r applicatio�l file No. LUA/SWP relating to real property legally described abo��. tE�e l�ndeisi<�nec3 as G;ant��r(�l, declares(dcc]are) that thr above d�scrib�d }�r��petly is llercby �stablishe� as hav�:�g a :imit to the amouiit of�itipe.vious �urface allo«�ed oil th� pro�erty :or ttie purpose of limiting storniwater flows and is subject to the following restrictions. The Grantor(s) hereby covenants(covenant) and agrees(agree) as follows: no more than square feet of impervious surface coverage is allowed on the property. Imperviaus surface means a hard surface area that either prevents or retards the entry of water into the soil mantle as under natural conditions before development; or that causes water to run off the surface in greater quantities or at an increased rate of flow from the flow present under natural conditions prior to development. Conunon iinpervious surfaces include, but are t�ot limited to, roof, walkways, patios, driveways, parkitlg lots, or storage areas, areas that are paved, graveled or made of packed or oiled earthen materials, or other surfaces that si�nilarly impede the natural infiltration of surface and storm water. City of Renton or its municipal successors shall have a noneaclusive perpetual access easement on the Property in order to ingress and egress over the Property for the sole purposes of inspecting and monitoring the Property's impervious surface coverage. This easement/restriction is binding upon the Grantor(s), its heirs, successors, and assigns unless ' c�r until a ne�� drainage or site plan is reviewed and approved by the Renton Development Services Division or its successor. IN V4'IT:�ESS WHEREOF, this Declaration of Covenant i� executed this __day of� , 20 GRANTOR, owner of the Pro�trty GR.��tiTUR, o�vner ot�thc Prop�rty� S�I�ATE UF V4'ASHINGTON ) C�)l_;�'i�Y OF KING )ss. On this day personally appeared before me: __ __ , to me known to be the individual(s) described in and who executed the �vithin and foregoing instrument and acknowledged that they signed the same as their frce and voluntary act and deed, for the uses and purposes therein stated. Gircn undcr tn}� hand and official scal this day c�f___ _-_ , 20 . PI IIli�CI I1�Illf; \utary Public in and for the State of Washington. residin� at M} appointment expires __ ___�'�_��, RECORDII�G REQUESTED BY AND VJHEI�` RECORDED MAIL TO: CITY CLERK'S OFFICE CITY OF RENTON 1055 SOUTH GRADY WAY RENTON, WA 98057 DECLARATI0:�1 OF COVENA�IT ' FOR CLEARING LIMIT Grantor: Grantee: City of Renton I.egal Description: - _ _-_ — --- Additional Legal(s) on: _ Assessor's Tax Parcel ID#: Iti CO'�SIDER�I ION of the appro�cd City �f Renton _ ��ri:;:: for application file No. LUA.!SWP relating to the real property ("Property") described abo��e, the Grantor(s), the o«-ner(sj iu fee of that Property, hereby declares (declare) that the Property is established as having a nati��e growth retention area for the purpose of� dispersing and treating stormv�tater flows and is subject to restrictions applying to vegetation rem��,tl in all designated areas showu in Exhibit A attached hereto, and hereby covenants (covenant) and avre�� (a��:�'�l as tullo;>.s: l. �n�� alt�ration; to criti�.il arca�. ;hcir buff�r;, and nati�� r��th ret�.nti�,n arca.; ,ha:l b� pursuant to applicable Renton A�unicipal Code. 2. The property within the native growth protection area(shown in Attachment A) shall b� inaintained in a forested condition, with the exception of open water and existing non-forested nati�e wetland plant communities. The following acti�•ities are allo��°ed and inust be do�ie in a nl:inner that maintains forested hydrologic conditions and soil stabilit}�: a. Removal of noxious weeds and non-nati��e vegetation using hand equipment, pro�ided that th��se areas are replanted with appropriate native vegetation. ' b. Removal of dangerous and diseased trecs. c. Passive recreation and related activities in�:ludui� tra�l�, nature ��win�, lishing, cam}�in�� areas, and other similar activities that do not require pern�anent structures, provided that cleared areas ��n�? areas of compacted �c�il :�ssociated ��itli tl��se ar�eas �nd facilities d�, n�t exceed eight percent of�he n.�ti�e growth retention arca. d. Tl�e nativc �rowth retcntion arca may cuntain utilitic, and utility cascrt�cnt� includii�g 11�� rontrol F3I��1Ps, but not including scptic systcros. � e. Limited irimmin� aud pruning of vege;tation for tl�e crcation and maintenance of��ie��s per applicable Reiiton :��lunicipal Cade. f. Tirnber hai-��est in accordance �vith the City of Renton Tree Clearing and Land Regulations, the Department of Natural Resources forest practices permit, and if applicable, the City of Renton Urban Separator Overlay Regulations. 3. City of Renton sha11 ha��e a nonexclusive perpetual access easement on the Property in order to ingress and egress over the Property for the sole purposes of inspecting and monitoring the Property's native growth retention area. 4. T'his easement/restriction is binding upon the Grantor(s), his/her (their) heirs, successors and assigns unless or until a new drainaec or site plan is reviewed and approved by the the Cit} of R�n'on or i2� Sl1C�,'SC:1r. ' IN ��v'ITNESS WHEREOF. this Declaration of('ovenant is exccuted thi� dav of 20 GRANTOR, owner of the Property CifZAi�T��)K. �>��vner of ihe 1'r��jicrty ST:�1TE UF �'��ASIIItiG�IU\ ) COtJNTY OF KING )ss. (�n tl�i� da�� p�rsona:ly appeared before tn�: _ __ _ , to in� known to be thc iildividual(sl described iii ai�d who executed the within and foregoing instrument and acknowledged that they signed the sanie as their free and voluntary act aiid deed, for the uses and purposes t}3crei�l stated. (;i��en und�r n�v har.d and ��fiicial scal thi� dav c�f . 20 ' -- . Printed name Notary Public in �nd for the Sta?c of�'aslun��;c�u. re:idin� at '��Iy appointmcnt czpires __ k ff Appendix F Operations and Maintenance Manual ' Vantage Point Apartments Technical�nformation Report Appendix F APPENDIX A MAINTENANCE REQUIREMbNTS FLOW CONTROL,CONVEYANCE,AND WQ F:ACILITIES ' NO. 1 - DETENTION PONDS Maintenance Defect or Problem Conditions When Maintenance Is Needed Results Expected When Component Maintenance Is Performed Site Trash and debris Any irash and debris which exceed 1 cubic foot ! Trash and debris cleared from site. per 1,000 square feet(this is about equal to the i amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation constitute a hazard to County personnel or the removed according to applicable , public. regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil,gasoline,concrete slurries or paint. according to applicable regulations. � Source control BMPs implemented if appropriate. No contaminants ; present other than a surface oil film. Grass/groundcover Grass or groundcover exceeds 18 inches in Grass or groundcover mowed to a height. height no greater than 6 inches. Top or Side Slopes Rodent hoies { Any evidence of rodent holes if facility is acting Rodents removed o�destroyed and of Dam, Berm or as a dam or berm,or any evidence of water dam or berm repaired. Embankment piping through dam or berm via rodent holes. Tree growth Tree growth threatens integrity of slopes,does Trees do not hinder facility not allow maintenance access,or interferes with performance or maintenar.ce maintenance activity. If trees are not a threat or i activities. not interfering with access or maintenance,they do not need to be removed. Erosion Eroded damage over 2 inches deep where cause Slopes stabilized using appropriate of damage is still present or where there is erosion control measures. If erosion � potentiai for continued erosion_ Any erosion is occurring on compacted slope,a observed on a compacted slope. licensed civil engineer should be ' j consulted to resolve source of ' erosion. ' Settlement Any part of a dam,berm or embankment that has Top or side slope restored to design settled 4 inches lower than the design elevation. dimensions. If settlement is significant, a licensed civil engineer should be consulted to determine the cause of the settlement. Storage Area Sediment Accumulated sediment that exceeds 10%of the Sediment cleaned eut to designed accumulation designed pond depth. pond shape and depth;pond reseeded if necessary to control erosion. Liner damaged Liner is visible or pond does not hold water as Liner repaired or repfaced. (If Applicable) designed. � InIeUOutlet Pipe. Sediment � Sediment filling 20%or more of the pipe. InleUou:{et pipes ciear of sediment. accumulation Trash and debris Trash and debris accumulated in inleUoutlet No trash or debris in pipes. � pipes{includes floatables and non-floatables). Damaged Cracks wider than%z-inch at the joint of the No cracks more than Y.-inch wide at inleUoutiet pipes or any evidence of soil entering the joint of the inleUoutlet pipe. at the joints of the inleUoutlet pipes. Emergency Tree growth Tree growth impedes flow or threatens stability of Trees removed. OverflowlSpil�way , spillway. Rock missing Only one layer of rock exists above native soil in Spiliway restored to design � area five square feet or larger or any exposure of standards. native soil on the spillway. U9�2009 2009 Surface VJater Design Manual—.Appendix A A-2 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES � NO. 4- CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Structure Trash and debris Trash or debris of more than Yz cubic foot which No Trash or debris blocking or is located immediately in front of the structure potentiaily blocking entrance to opening or is btocking capacity of the structure by structure. more than 10%. Trash or debris in the structure that exceeds'/, No trash or debris in the structure. the depth from the bottom of basin to invert the lowest pipe into or out oi the basin. Deposits of garbage exceeding 1 cubic foot in No condilion present which would volume. attract or support the breeding of insects or rodents. Sediment Sediment exceeds 60%of the depth from the Sump of structure contains no bottom of the structure to the invert of the lowest sediment. pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the � invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Damage to frame Corner of frame extends more than'/.inch past Frame is even with curb. and/or top siab curb face into the st�eet(If applicable}. Top siab has holes larger than 2 square inches or Top slab is free of holes and cracks. cracks wider than Y.inch. Frame nof sitting flush on top slab,i.e., Frame is sitting flush on top slab. separation of more than'/,inch of the frame from the top slab. Cracks in wails or Cracks wider than'/�inch and longer than 3 feet, Structure is sealed and structurally bottom any evidence of soil particles entering sVucture sound. through cracks,or maintenance person judges that structure is unsound. Cracks wider than Y�inch and longer than 1 foot No cracks more than'l,inch wide at , at the joint of any inleUoutlet pipe or any evidence the joint of inieUo�tlet pipe. of soil particles entering structure through cracks. Settlement/ Structure has settied more than 1 inch or has Basin rep►aced or repaired to design misalignment rotated mo�e than 2 i�ches out of alignrrent. standards. Damaged pipe joints Cracks wider than%z-inch at the joint of the No cracks more than Y,-inch wide at inleVoutlet pipes or any evidence of soii entering the joint of inleUoutiet pipes. tne structure at the joint of the inleUoutlet pipes. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil,gasoline,concrete slurcies or paint. according to applicabie regulations. Source contrcl BMPs implemented if appropriate. No contaminants present other than a surface oil fiim. Ladder rungs missing Ladder is unsafe due to missing rungs, Ladder meets design standards and or unsafe misalignment,rust,cracks,or sharp edges. allows maintenance person safe access. , FRQP-T Section Damage T section is not securely attached to structure T section securely attached to waU � wall and outiet pipe structure should support at and outiet pipe. � least 1,000 Ibs of up or down pressure. �� Structure is not in upright position(aliow up to Structure in correct position. i 10%from plumb). Conrections to outlet pipe are not watertight or Connections to outlet pipe are water show signs of deteriorated grout. tight;structure repaired or repiaced and works as designed. j Any holes—other than designed holes—in the Structure has no holes other than structure. • designed holes. Cleanout Gate Damaged or missing Cleanout gate is missing. i Rep�ace cleanout gate. 2009 Surface Water Design Manual-Appendix A 1,`9��)09 :'�-7 APPE'.vDIX A hfAWTENANCE REQUIREMENTS FLOW CO\TROL,CONVEYAIv`CF, �VD WQ FACILITIES NO. 4-CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When I _ Component Maintenance is Performed � Cleanout gate is not watertight. Gate is watertight and works as designed. Gate cannot be moved up and down by one Gate moves up and down easily and I maintena�ce person. is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Orifice Plate Damaged or missing Control device is not working properly due to Plate is in place and works as missing,out of place,or bent orifice plate. designed. ' Obstructions Any trash,debris,sediment,or vegetation Plate is free oi alI obstructions and I blocking the plate works as designed. Overflow Pipe I, Obstructions Any trash or debris blocking(or naving the Pipe is free of all obstructions and potential of blocking)the overflow pipe. works as designed. i — - Deformed or damaged �ip of overfiow pipe is bent or deformed. , Overtlow pipe does not aliow tip overflow at an elevation lower:han � design InIeUOutlet Pipe Sediment Sediment fiili�g 20%or more of the pipe. InleUoutlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inietlout�et No trash or debris in pipes. pipes(includes floatables and non-floatables). Damaged Cracks wider than'/z-inch at the joint of the No cracks more than'/.-inch wiae at inleUoutlet pipes or any evidence of soil entering the joint of the in!el,ioutlet pipe. at the joints of the inleUoutlet pipes. Metal Grates Unsafe grate opening Grate with opening wider than'/8 inch. Grate opening meets design (If Applicable) standards. � Trash and debris Trash and debris that is blocking more than 20% Grate free of trash and debris. 1 ; of grate surface. footnote to guidelines for disposal � Damaged or missing Grate missing or broken member(s)of the grate. Grate is in place and meets design , standards. Manhole Cover/Lid Coverllid not in place ; Cover/lid is missing or only partialiy in place. Cover/lid protects opening to Any open structure requires urgent structure. I maintenance. � Locking mechanism Mechanism canno:be opened by one Mechanism opens with proper tools j Not Working maintenance person with proper tools.Bolts cannot be seated. Self-locking cover/lid does not work. Coverllid difficult to One maintenance person cannot remove i Cover/lid can be removed and Remove , coverllid after applying 80 Ibs.of lift. ! reinstalled by one maintenance , , ; person. 1/9/2009 2009 Surface Water Design Manual—Appendix A A-8 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES � NO. 5- CATCH BASINS AND MANHOLES Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component � Maintenance is Performed Structure Sediment Sediment exceeds 60%of the depth from the Sump of catch basin contains no bottom oi the catch basin to the invert of the sediment. lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Trash and debris Trash or debris of more than Yz cubic foot which No Trash or debris blocking or is located immediately in front of the catch basin potentially blocking entrance to opening or is blocking capacity of the catch basin catch basin. by more than 10%. Trash or debris in the catch basin that exceeds No trash or debris in the catch basin. '/,the depth from the bottom of basin to invert the lowest pipe into or out of the basin. Dead animals or vegetation that could generate No dead animais or vegetation odors that could cause complaints or dangerous present within catch basin. gases(e.g.,methane). � Deposits of garbage exceeding 1 cubic foot in No condition present which would volume. attract or support the breeding of insects or rodents. Damage to frame Corner of frame extends more than'/.inch past Frame is even with curb. and/or top slab curb face into the street(If applicable). Top slab has holes larger than 2 square inches or Top slab is free of holes and cracks. cracks wider than Y.inch. , Frame not sitting Flush on top slab,i.e., Frame is sitting flush on top slab. i separation of more than'/.inch of the frame from ' the top slab. ' Cracks in walls or Cracks wider than Yz inch and longer than 3 feet, Catch basin is sealed and bottom I any evidence of soil paRicles entering catch structurally sound. , basin through cracks, �r maintenance person ' judges that catch basin is unsound. Cracks wider than Yz mch and longer than� foot No cracks more than �!,inch wide at at the joint of any inleVoutlet pipe or any evidence the joint of inleUoutlet pipe. of soil particles entering catch basin through cracks. SettlemenU Catch basin has settled more than 1 inch or has Basin replaced or repaired to design ; misalignment rotated more than 2 inches out of aiignment. standards. ' Damaged pipe joints Cracks wider than Yrinch at the joint of the No cracks more than Y.-inch wide at inleUoutlet pipes or any evidence of soil entering the joint of inlet/outlet pipes. the catch basin at the joint of the inleUoutlet pipes. Contaminants and Any evidence of contaminants or poltution such Materials removed and disposed of pollution as oil,gasoline,concrete slumes or paint. according to applicable regulations. Source controt BMPs implemented if appropriate. No contaminants present other than a surface oil film In1eVOutlet Pipe Sedlment i Sediment filling 2�%or more of the pipe. InleVoutlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inleUoutlet No trash or debris in pipes. pipes(includes fioatables and non-floatabies). i Damaged Cracks wider than Yrinch at the joint of the No cracks more than Y.-inch wide at inlet/outlet pipes or any evidence of soil entering the joint of the inleUoutlet pipe. at the joints of the inleVoutlet pipes. 2�09 Surface Water Design'.vlanual Append��c :'� 1-`9i?009 .A-9 APPE�'l)IX A 1�1,41ti7�F��A'�('F Itt�(1L;11z}�.�1EV"I�� 1=1.OV�''(�UVTROL,COi�ti'I;Y.a\CI��. :�\D�V11 FaC1LI"I�IES NO. 5—CATCH BASINS AND MANHOLES I Maintenance Defect or Problem ' Condition When Maintenance is Needed ' Resuits Expected When Component � I Maintenance is Performed � Metal Grates Unsafe grate opening Grate with opening wider than'/e inch. Grate opening meets design ' (Catch Basins) standards. Trash and debris Trash and debris that is blocking more than 20% Grate free of trash and debris. ' of grate surface. footnote to guidelines for disposal � Damaged or missing i Grate missing or broken member(s)of the grate. Grate is in place and meets design Any open structure requires urgent standards. maintenance. Manhole CoverlLid Coverllid not in place Coverllid is missing or only parially in place Coverllid protects opening to Any open structure requires urgent structure. maintenance. _� Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. ' Not\Norking maintenance person with proper tools.Boits cannot be seated. Self-locking coverllid does not work. Coverllid difficult to One maintenance person cannot remove Cover/lid can be removed and Remove coverllid after applying 80 Ibs.of lift. reinstalled by one maintenance ' person , 1 9 =(ii�9 2009 Surface Vb'ater Design Manual—Appendix A :a-�o APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES NO. 6-CONVEYANCE PIPES AND DITCHES Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Pipes Sediment 8 debris Accumulated sediment or debris that exceeds Water flows freely through pipes. accumulation 20%of the diameter of the pipe. Vegetation/roots Vegetationlroots that reduce free movement of Water flows freely through pipes. water through pipes. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil,gasoline,concrete slurries or paint. according to applicable regulations. Source conUol BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective Protective coating is damaged;rust or coRosion Pipe repaired or replaced. coating or corrosion is weakening the structural integrity of any part of pipe. Damaged Any dent that decreases the cross secdon area of Pipe repaired or replaced. pipe by more than 20%or is determined to have weakened structural integrity of the pipe. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debns cleared from square feet of ditch and slopes. ditches. Sediment Accumulated sediment that exceeds 20%of the Ditch Geaned/flushed of all sediment accumulation design depth. and debns so that it matches design. . Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation constitute a hazard to County personnel or the removed according to applicable public. regulations. No da�ger of noxious vegetation where County personnel or the public might normally be. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil,gasoline,concrete slurries or paint. according to applicable regulations. ' Source conVol BMPs implemented if appropriate. No contaminants ' present other than a surface oil film. IVegetation VegetaUon that reduces free movement of water Water flows freely through ditches. through ditches. Erosion damage to Any erosion observed on a ditch slope. Slopes are not eroding. slopes Rock lining out of One layer or less of rock exists above native soil Replace rocks to design standards. place or missing(If area 5 square feet or more, any exposed native Applicable) soil. ' 1 � I � 2009 Surface Water Design Manual—Appendix A 1/9/2009 A-1 1 APPENDIX A v1A]�ITENA'�ICE REQUIRE�9EtiTS FLU�V COtiTRUL,CONVEYANCE,AND VVQ FACfLITIES NO. 7- DEBRIS BARRIERS (E.G., TRASH RACKS) ' Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When �, Component Maintenance is Performed. Site Trash ard debris Trash or debris plugging more than 20%of the Barrier clear to receive capacity flow. i area of the barrier. Sediment Sediment accumulation of greater than 20%of Barrier clear to receive capacity flow. accumulation the area of the barrier Structure Cracked broken or Structure which bars attached to is damaged- Structure barrier attached to is loose pipe is loose or cracked or concrete structure is sound. , cracked,broken of loose. Bars Bar spacing Bar spacing exceeds fi inches. Bars have at most 6 inche spac:ng. Damaged or missing Bars are bent out of shape more than 3 inches. Bars in place with no bends more bars than'/inch. Bars are missmg or en4ire barner missir.g. Bars in place according to design. Bars are toose and rust is causing 50% Repair or replace bamier to desigr I deterioration to any part of barrier. standards. i 1 9 200y 2009 Surface Water Design�Sanual Appendix A :1-12 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL,CONVEYANCE,AND WQ FACILITIES NO. 9- FENCING Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Site Erosion or holes Erosion or holes more than 4 inches high and 12- No access under the fence. under fence 18 inches wide permitting access through an opening under a fence. Wood Posts,Boards Missing or damaged Missing or broken boards,post out of plumb by No gaps on fence due to missing or and Cross Members parts more than 6 inches or cross members broken broken boards, post plumb to within 1 Yz inches,cross members sound. Weakened by rotting Any part showing structural deterioration due to All parts of fence are structurally or insects rotting or insect damage sound. Oamaged or failed Concrete or metal attachments deteriorated or Post foundation capable of post foundation unable to support posts. supporting posts even in strong wind. Metal Posts,Rails Damaged parts Post out of plumb more than 6 inches. Post plumb to within 1'/:inches. and Fabric Top rails bent more than 6 inches. Top rail free of bends greater than 1 inch. Any part of fence(including post,top rails, and Fence is aligned and meets design fabric)more than 1 foot out of design alignment. standards. Missing or loose tension wire. Tension wire in place and holding fabric. Deteriorated paint or Part or parts that have a rusting or scaling Structurally adequate posts or parts protective coating condition that has affected structural adequacy. with a uniform protective coating. Openings in fabric Openings in fabric are such that an 8-inch Fabric mesh openings within 50%of diameter ball could fit through gnd size ' -, ' I i 1/9,2009 2009 Surface Water Design Manual—Appendix A A-14 I I APPENDIX A MAINTENAVCE REQUIREMEI�'7'S FOR FLOW CONTROL,CONVEYA�ICE,AND WQ FACILITIES ' NO. 10- GATES/BOLLARDS/ACCESS BARRIERS � Maintenance Defect or Problem Conditions When Maintenance is Needed i Results Expected When � i Component Maintenance is Performed Chain Link Fencing Damaged o►missing Missing gate. Gates in place. Ga:e � members Broken or missing hinges sucn that gate cannot Hinges intact and lubed.Gate is be easily opened and closed by a maintenance working freely. person. Gate is out of plumb more than 6 inches and Gate is aligned and vertical. � � more than 1 foot out of design alignment. ' Missing stretcher bar,stretcher bands,and ties. Stretcher bar,bands,and ties in place. Locking mechanism Locking device missing,no-functioning or does Locking mechanism prevents does not lock gate not link to all parts. opening of gate. Openings in fabric Openings in fabric are such that an 8-inch Fabric mesh openings within 50%of diameter ball could fit through. grid size. Bar Gate Damaged or missing Cross bar does not swing open or closed,is Cross bar swings fully open and cross bar missing or is bent to where it does not prevent closed and prevents vehicle access. vehicle access. Locking mechanism Locking dev�ce missing,no-functioning or does Locking mechanism prevents does not lock gate not link to all parts. opening of gate. Support post Support post does not hold cross bar up. Cross bar held up preventing vehicle damaged access into facility. Bollards Damaged or missing Bollard broken,missing,does not fit into support No access for motonzed vehicles to ' hole or hinge broken or missing. get into facility. � Does not lock Locking assembly or lock missing or cannot be No access for motorized vehicles to � attached to iocac bollard in place. get into facility. Boulders Dislodged Boulders not located to prevent motorized vehicle No access for motorized vehicles to � access. get into facility. Circumvented Motorized vehicles going around or between No access for motorized vehicles to � boulders. , get into facility. ' _'Ui�9 Surface 1V;�tcr Design '�4anial App�i,di�r� l;'9:'_009 A-15 APPF'VDIa A MAII�"I'EN,atiCE REQliIKEMENTS FLOW CONTROL,C0�7VE�'AI�CE, AND 14`Q FACILITIES _ t NO. 11 -GROUNDS (LANDSCAPING) � Maintenance Defect or Problem Conditions When Maintenance is Needed Resuits Expected When Component Maintenance is Performed Site Trash or litter Any trash and debris which exceed 1 cubic foot Trash and debris cleared from site. , per 1,000 square feet(this is about equal to the � amount of trash it would take to fill up one standard size office garbage can). In general, there shouid be no visual evidence of dumping. Noxious weeds Any noxious o�nuisance vegetation which may Noxious and nuisance vegetation ' constitute a hazard to County personnel or the removed accarding to applicable public. regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil,gasoline,concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropnate. No contaminants present other than a surface oii film. Grasslgroundcover Grass or groundcover exceeds 18 inches in Grass or groundcover mowed to a height. height no greater than 6 inches. Trees and Shrubs Hazard Any tree or limb of a tree identified as having a No hazard trees in facility. potentiai to fall and cause property damage or threaten human life. A hazard tree identified by i ; a qualified arborist must be removed as soon i as possible. ' Damaged Limbs or parts of trees or shrubs that are split or Trees and shrubs with less than 5% . broken which affect more than 25%of the total i of total foliage with split or broken foliage of the tree or shrub. limbs. Trees or shrubs that have been blown down or No blown down vegetation or knocked over. � knocked over vegetation. Trees or shrubs free of injury. � Trees or shrubs which are not adequately Tree or shrub in place and ' supported or are leaning over,causing exposure adequately supported;dead or of the roots. diseased trees removed. APPENDIX A MAIN'TENAI�CE REQUIREMENTS FOR FLOW COtvTTROL,CONVEYANCE,AND WQ FACILITIES NO. 12-ACCESS ROADS - Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Site Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 Roadway drivable by maintenance square feet(i e.,trash and debris would fill up vehicles. or�e standards size garbage can). Debris which could damage vehicle tires or Roadway drivable by maintenance ', prohibit use of road. vehicles. Contaminants and ' Any evidence of contaminants or poliution such Materials removed and disposed of pollution as oil,gasoline,concrete slurries or paint. according to applicable regulations. Source control BMPs implemented rf appropriate. No contaminants present other than a surtace oil film. Blocked roadway Any obstruction which reduces clearance above � Roadtivay overhead clear to 14 feet road surface to(ess than 14 feet. high. i Any obstruction restricting the access to a 10-to At least 12-foot of width on access 12 foot width for a distance of more than 12 feet road. � or any point restricting access to less than a 10 foot width. Road Surface Erosion,settlement, Any surface defect which hinders or prevents Road drivable by maintenance ' potholes,soft spots, maintenance access. vehicles. ; ruts Vegetation on road Trees or other vegetation prevent access to Maintenance vehicles can access surface facility by maintenance vehicles. facility. Shoulders and Erosion � Erosion within 1 foot of the roadway more than 8 Shoulder free of erosion and I Ditches inches wide and 6 inches deep. matching the surrounding road. Weeds and brush Weeds and brush excaed 18 inches in height or � Weeds and brush cut to 2 inches in � hinder mainlenance access. height or cleared in such a way as to aliow maintenance access. I P�lodular Grid Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of I Pavement pollution as oil,gasoiine,concrete slurries or paint_ according to applicable regulations. , i I Source control BMPs implemented if appropriate. No contaminants ; present other than a surface oil film. Damaged or missing Access surFace compacted because of broken on � Access road surtace restored so ! missing modular block. road infiltrates. 2009 Surface W'ater Design Manual - Appendix A 1/9{2009 A-17 � APPET�DIX A ?�4AII�TENANCE REQUIREMENTS FOR FLOV4'CONTROL,CONVEYA�iCE. AND��lQ FACILI7IES NO. 24-CATCH BASIN INSERT ' Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Media lnsert Visible Oil Visible oil sheen passing through media Media inset replaced. Insert does not fit Flow gets into catch basin without going through All flow goes through media. catch basin properly media. Filter media plugged Filter media plugged. Flow through filter media is normal. Oil absorbent media Media oii saturated. Oil absorbent media repiaced. saturated Water saturated Catch basin insert is saturated with water,which Insert replaced. no ionger has the capacity to absorb. Service life exceeded Regular interval replacement due to typical Media replaced at manufacturer's average life of inedia insert product,typically one recommended interval. month. Seasonal When storms occur and during the wet season. Remove,clean and replace or install maintenance ' new insert after major storms, monthly during the wet season or at manufacturer s recommended intervai. � � 2009 Surface Water Design Manua►—Appendix A A-�� , c'.?5 RAtV G.aRnE'�; C.2.5.3 MAI�ITENANCE INSTRUCTI0�1S FOR A RAIN GARDEN If the rain garden flo�•control BMP is proposed for a project,the following maintenance and operation instructions must be recorded as an attachment to the required declaration of covenant and grant of easement per Requirement 3 of Section C.13.3 (p. C-18). The intent of these instructions is to explain to Yuture property owners,the purpose of the BMP and haw it must be maintained and operated. T'hese instructions are intended to be a minimum;DDES may require additional instructions based on site- specific conditions. Also, as the County gains more experience with the maintenance and operation of these BMPs, future updates to the instructions ��ill be posted on King County's Surface Water Design �tlanuad website. ❑ TEXT OF INSTRUCTIONS Your property contains a stormwater management flow control BMP (best management practice)called a "rain garden,"which was installed to mitigate the stormwater quantity and quality impacts of some or all of the impervious or non-native pervious surfaces on your property. Rain gardens, also known as "bioretention,"are vegetated closed depressions or ponds that retain and filter stormwater from an area of impervious surface or non-native pervious surface. The soil in the rain garden has been enhanced to encourage and support vigorous plant growth that serves to filter the water and sustain infiltration capacity. Depending on soil conditions, rain gardens may have water in them throughout the wet season and may overflow during major storm events. The size, placement, and design of the rain garden as depicted by the flow control BMP site plan and design details must be maintained and may not be changed without written approval either from the King County Water and Land Resources Division or through a future development permit from King County. Plant materials may be changed to suit tastes, but chemical fertilizers and pesticides must not be used. Mulch may be added and additional compost should be worked into the soil over time. Rain gardens must be inspected annually for physical defects. After major storm events, the system should be checked to see that the overflow system is working properly. If erosion channels or bare spots are evident, they should be stabilized with soil, plant material, mulch, or landscape rock. A supplemental watering program may be needed the first year to ensure the long-term survival of the rain garden's vegetation. Vegetation should be maintained as follows: 1) replace all dead vegetation as soon as possible; 2) remove fallen leaves and debris as needed; 3) remove all noxious vegetation when discovered;4)manually weed without herbicides or pesticides; 5)during drought conditions, use mulch to prevent excess solar damage and water loss. 2009 Surface��v'ater Design?�9anual-Appendix C I/912009 C-63 C.2.6 PERMEABLE PAVEMENT some or all of the paved surfaces on your property. Permeable pavements reduce the amount of rainfall that becomes runoff by allowing water to seep through the pavement into a free-draining gravel or sand bed,where it can be infiltrated into the ground. The type(s)of permeable pavement used on your property is: 0 porous concrete, ❑ porous asphaltic concrete, ❑ permeable pavers, ❑ modular grid pavement. The area covered by permeable pavement as depicted by the flow control BMP site plan and design detaiis must be maintained as permeable pavement and may not be changed without written approval either from the King County Water and Land Resources Division or through a future development permit from King County. Permeable pavements must be inspected after one major storm each year to make sure it is working properly. Proionged ponding or standing water on the pavement surface is a sign that the system is defective and may need to be replaced. If this occurs, contact the pavement installer or the King County Water and Land Resources Division for further instructions. A typical permeable pavement system has a life expectancy of approximately 25-years. To help extend the useful life of the system, the surface of the permeable pavement should be kept clean and free of leaves, debris, and sediment through regular sweeping or vacuum sweeping. The owner is responsible for the repair of all ruts, deformation, andlor broken paving units. ❑ TEXT OF INSTRUCTIONS FOR VEGETATED PERMEABLE PAVEMENT � ( Your property contains a stormwater management flow control BMP (best management practice)called � "grassed modular grid pavement,"which was installed to minimize the stormwater quantity and quality ` impacts of some or all of the paved surfaces on your property. Grassed modular gnd pavement has the � runoff characteristics of a lawn while providing the weight-bearing capacity of concrete pavement. The � grassed surface not only minimizes runoff quantity, it helps to filter pollutants generating by vehicular use � of the surtace. The composition and area of grassed modular grid pavement as depicted by the flow control BMP site plan and design details must be maintained and may not be changed without written approval either from the , King County Water and Land Resources Division or through a future development permit from King County. Grassed modular grid pavement must be inspected after one major storm each year to make sure it is working properly. Prolonged ponding or standing water on the pavement surface is a sign that the system defecti�e and may need to be replaced. If this occurs, contact the pavement instalfer or the King County Water and Land Resources Division for further instructions. The grassed surface of the pavement must be regularly mowed and maintained in a good condition. Bare spots must be replanted in the spnng or fall. ?009 Su;face Water Design Manual-App�ndix C I:'9-2009 C-67