Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
TIR-3910
Grant Avenue Townhomes Denton, Washington Technical Information Report rE w 42�w e September 14, 2017 Pacific Engineering Job No. 15022 TECHNICAL INFORMATION REPORT FOR Grant Avenue Townhomes RENTON, WASHINGTON May 30, 2017 PREPARED FOR Satwant Singh, Skyline Properties, Inc. 50 116th Avenue SE, Suite 120 Bellevue, WA 98004 Phone: (425) 455-2065 E-mail: pmvrsingh@gmail.com PREPARED BY Pacific Engineering Design, LLC. 15445 53rd Avenue S Seattle, WA 98188 Phone: (206) 431-7970 TABLE OF CONTENTS Page I. PROJECT OVERVIEW ............................................................................................... 3 Figure 1 Technical Information Worksheet to Follow ...................................................4 Figure 2 Site Location Map to Follow ........................................................................... 5 Figure 3 Drainage Basin, Subbasin and Site Characteristics .......................................6 Figure4 Soils ............................................................................................................... 7 11. CONDITIONS AND REQUIREMENTS SUMMARY .................................................... 8 Ill. OFF SITE ANALYSIS ............................................................................................... 15 Task 1 Study Area Definition and Maps ..................................................................... 16 Task 2 Resource Review ........................................................................................... 17 Task 3 Field Inspection .............................................................................................. 18 Task 4 Drainage System Description and Potential Problems ...................................19 Task 5 Mitigation of Existing or Potential Problems ...................................................19 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ... 20 Part A Existing Site Hydrology ................................................................................... 21 Part B Developed Site Hydrology ............................................................................... 22 Part C Performance Standards .................................................................................. 27 PartD Flow Control System ....................................................................................... 28 Part E Water Quality System ..................................................................................... 36 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN (REVISED 6/26/2012) ............ 40 VI. SPECIAL REPORTS AND STUDIES ....................................................................... 46 VII. OTHER PERMITS ................................................................................................... 47 VIII. CSWPPP ANALYSIS AND DESIGN ...................................................................... 48 IX BOND QUANTITIES, FACILITY SUMMARIES AND DECLARATION OF COVENANT................................................................................................................... 52 X. OPERATIONS AND MAINTENANCE MANUAL ....................................................... 53 N I. Proiect Overview The proposed project will develop 8 townhome buildings (total 36 units) in parcel 202305- 9052. The site is located two parcels north of the northeast corner of the intersection of South 18th Street and Grant Avenue South. The address of the site is 1600 Grant Avenue South. The site area is 2.11 acres. The site is a trapezoidal property that is approximately 583' x 158' (average) with frontage on its western short side along Grant Avenue South. The project site includes onsite development area and offsite improvement area along the Grant Avenue South frontage. Total project site area is approximately 2.17 acres including offsite improvement along Grant Avenue South. The site is located in the City of Renton Residential Multi -Family (RM-F) zone. The site is surrounded by single-family residents to the east and multi -family residences to the west and south and a Puget Sound Power and Light Company property to the north. The site is located in the Thunder Hills Creek drainage sub -basin of the Black River Drainage basin. The site is located in the Duration with Forested conditions flow control area (Duration flow control with Forested site conditions) and Enhanced Basic water quality control is required because the proposed development is a multi -family development. There is a single family house (built 1946) on the west portion of the site near the Grant Avenue South. The house will be demolished and removed for the proposed development. The remainder of the property is covered with grass with some scattered trees. The site is hilly with average slope of 11 % slopes westerly toward Grant Avenue South. There is no sensitive area on the site and no difficult conditions for the proposed development. For the onsite improvement, new plus replaced impervious area is approximately 1.35 acres, new pervious area is approximately 0.76 acres. Flow control BMPs, Native growth protection area (2,595 sf.) and pervious concrete sidewalk (8,976 sf.) are used to treat approximately 33.4% of the 36-lot areas. A combined detention/wet vault is used to provide the required Duration standard forested site conditions flow control and a treatment train of wet vault and StormFilter manhole with CSF cartridges is used to provide the required Enhanced Basic water quality treatment. The offsite frontage improvement creates approximately 1,760 square feet of new impervious area (520 square feet of it is pollution generating impervious area) and no new pervious area. For flow control, the new impervious area created by the offsite improvement is counted as bypassed target area Per KCSWDM Section 1.2.3.2.E. The onsite detention vault is oversized, so that the developed onsite detained runoff plus the offsite bypassed runoff meets the required Duration standard forested site conditions flow control requirements at the point of convergence (SDMH#1 at Grant Avenue South). For water quality treatment, new pollution generating area is only 520 square feet and is counted as untreated discharge per KCSWDM Section 1.2.8.2.D bypassing the water quality treatment facilities. 3 Figure I Technical Information Worksheet to Follow KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Project OwnerSkyline Properties, Inc. Phone (425) 455-2065 Address 50 116 th Ave. SE . , # 12 0 Bellevue, WA 98004 Project Engineer Jings ong Feng, P.E. Company Pacific Engr. Design, LLC. Phone (206) 431-7970 Part 3 TYPE OF PERMIT APPLICATION ❑ Landuse Services Subdivison / Short Subd. / UPD ® Building Services M/ Commerical / SFR ® Clearing and Grading ® Right -of -Way Use ❑ Other Part 2 PROJECT LOCATION AND DESCRIPTION Project Name Grant Avenue Townhomes DDES Permit # Location Township 23 Range 5 Section 20 Site Address 1600 Grant Ave. S . Renton, WA 98055 Part 4 OTHER REVIEWS AND PERMITS. ❑ DFW HPA ❑ Shoreline ❑ COE 404 Management ❑ DOE Dam Safety ® StructumL Rocke cult/ ❑ FEMA Floodplain ® ESA Section 7 ❑ COE Wetlands ❑ Other Park 5 PLAN AND REPORT" INFORMATION Technical Information Report Site Improvement Plan (Engr. Plans) Type of Drainage Review Full Targeted / Type (circle one): Full Modified / (circle): arge 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: 2009 Surface Water Design Manual 1/9/2009 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 7 MONITORING REQUIREMENTS Monitoring Required: (yes / No Start Date: Completion Date: _ Part 8 SITE COMMUNITY AND DRAINAGE BASIN Describe: Community Plan : Soos Creek Special District Overlays: DrainageBasin:Thunder Hills Creek sub -basin of Black River Drainage basin. Stormwater Requirements: Duration with Forest Condition Flow Control Part 9 ONSITE AND ADJACENT SENSITIVE AREAS 0 River/Stream Thunder Hills Creek ❑ Steep Slope ❑ Lake ® Erosion Hazard ❑ Wetlands 0 Landslide Hazard Moderate ❑ Closed Depression ❑ Coal Mine Hazard ❑ Floodplain ❑ Seismic Hazard ❑ Other ❑ Habitat Protection Part 10 SOILS Soil Type Slopes AgC 8% to 15% AgD 15% to 30% ❑ High Groundwater Table (within 5 feet) ❑ Sole Source Aquifer ® Other ❑ Seeps/Springs ❑ Additional Sheets Attached Erosion Potential Moderate Severe 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-OffsiteAnalysis Duration with forest condition ❑ Sensitive/Critical Areas Flow control and Enhanced Basic 0 SEPA Water quality treatment. ❑ Other Ll Additional Sheets Attached Part 12 TIR SUMMARY SHEET provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: Storm drainage system, at Grant Avenue South name or description) Core Requirements (all 8 apply) Discharge at Natural Location Number of Natural Discharge Locations: 1 at SDMH# 1 Offsite Analysis Level: Q/ 2 / 3 dated: Flow Control Level: 1 < / 3 or Exemption Number Incl. facility summary sheet Small Site BMPs Perforated connections Conveyance System Spill containment located at: combined etention wet vault & StormFilter manhole Erosion and Sediment Control ESC Site Supervisor: Contact Phone: After Hours Phone: Maintenance and Operation Responsibility: Private / ublic If Private, Maintenance Log Required: Yes / No Financial Guarantees and Provided: Yes / No Liability Water Quality Type: Basic / Sens. Lake C Enhanced Basicm Bog (include facility summary sheet) or Exemption No. Landscape Management Plan: GDNo Special Requirements as applicable Area Specific Drainage Type: CDA / SDO / MDP / BP / LMP / Shared Fac. / one Requirements Name: Floodplain/Floodway Delineation Type: Major / Minor / Exemption /None 100-year Base Flood Elevation (or range): Datum: Flood Protection Facilities Describe: N/A Source Control Describe Ianduse: Multi -Family (comm./industrial Ianduse) Describe any structural controls: 2009 Surface Water Design Manual 3 1/9/2009 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Oil Control High -use Site: Yes Treatment BMP: Maintenance Agreement: Yes with whom? Other Drainage Structures Describe: Combined detention/wet vault StormFilter manhole with CSF cartridges. Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION AFTER CONSTRUCTION Clearing Limits Stabilize Exposed Surfaces Cover Measures Remove and Restore Temporary ESC Facilities Perimeter Protection 0 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 F1 Other 0 Dewatering Control E) Dust Control UJ Flow Control Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Su mary and Sketch) Flow Control Type/Description Water Quality Type/Description Detention Comb. detention/ ❑ Bio-filtration wet vault Comb. detention/ ❑ Infiltration 0 Wetpool wet vault — StormFilter MH Ll Regional Facility Media Filtration w/CSF cartridges Perforated J Shared Facility L) Oil Control Ul Flow Control BMPs connections preserve ex. tree Spill Control Control BMPs Pervious concrete❑Flow LJ Other S i d e Wa I k S ❑ Other Grasscrete vault access drivew4 2009 Surface Water Design Manual 4 1/9/2009 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS O Drainage Easement a Cast in Place Vault ❑ Covenant 0 Retaining Wall ❑ Native Growth Protection Covenant 0 Rockery > 4' High ❑ Tract ❑ 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 knowledge the information rovided here is accurate. '11 2009 Surface Water Design Manual 1/9/2009 Figure 2 Site Location Map to Follow C yi -z4sz` �'.r j'ty"*.,1....1J �. -€€ Yam. n r "�° .L. d �r„ „''• S" x;. O F IT L d $!$ -T^ ` + j � P qL.i." i€ i ` :� € # +�.,� Y`t rida74— III _ t '- g,7 4 L F,as er r;L 7 m�N�ao.tc2� �i ' o Ail! €�k 8E T1Y df rN��NE {k •-•� r t4� _7Yd�31+ p'-f0 m N -o i � " � � .i � �� �. �— i � � �� `f ,��-�-?-t�- ° � �-" � ; �.r �� •tee, � L � � d` F r 8 E � � L r cam..€. '• t` `{ 4{} >` O N N TJ.T77 rL ` �FE Ji WE I N .p-� N W ! Filzure 3 Drainage Basin, Subbasin and Site Characteristics Y �� �� .' � 1 '= — _ ��.:_ ..�...__ f L5 �' � r _ -� r � �- �- 4 � �. ;;e � -_ � - .-_ � , � t ;' k Figure 4 Soils a yU I Y®' z //W� `i W J A (L G m N � O 7 U p m m ip O E UN 3 NONE —00 O U Lo N -fl a) "O N (6 C M w O m CL m o 7d m c,: E C) N o .0 o. r C.) (m) U N O (p N N m U w C (6 a) C p N 3 a) C m O a) Q� ` o m a) m m U m — O CL O N m m U U tmp Q' C z�E N Q p C m a�pmc-) .a 'O d r m w0 a) m 3 U U)E N E N O 'D C 2 tmp 0) a)0 U � 'D 00 a) U C 0 � N aN N d E o a)o U�U m E a) :2 o.-0Q U C O mLO L O m N m a) CLN Q U � m c U t 0 M C 0O � N O C_ i N c 2 M — Y o m E O) p N .o O a) a) L a) i r N L pCL 3 m 0 2 Q 0 { CL:� N N O m E m fl O CL N p a) m I N o. m E NL-1 a) NL.. N C D m O .N O m >' O 'O ca O I (6 CL fl m CL m 'N C t O L N N 3 � NC:L G' CL (13 m — mEmE 1 0 Q N P OU .= O w N w a m LL c U M r s d M O T C C M _m M m m O d Q d O (n d J f0 Z N m d M E2 w O Of O o p m t CL o cn cn Z > 'S O US ami °' in O of 5 D :E-1 Q is c le 4 Q) r @ o CL yy C ` 0 Y i> Q V) C O N C c Q) >>N d (n N CL ,J.. CL M E N d 'O O m m a m a a a V — 3 w ° `o M O o Q) m c ° s0. O o o CL W °CL d o o `o Q LL 3 O T N > > 'O M N Q) V Q) U C 'O > Y Q) 'O d Q 0 0 (� (� � (� C O p o m m M U _O U M C� m (D c � > M J C ) N d O 12 M � M � a) J) C "Q O V) � US m c a y @ dq�f 0# CL t f j' p_ + n v '? aix ._ op E 4 Q co anti a m D U m z g Soil Map —King County Area, Washington Map Unit Legend King County Area, Washington (WA633) Map Unit Symbol Map Unit Name Acres in AOI Percent ofAO1 AgC Alderwood gravelly sandy loam, 8 to 15 percent slopes 1.2 53.9% AgD Alderwood gravelly sandy loam, 15 to 30 percent slopes 1.1 46.1 // Totals for Area of Interest 2.3 100.0% i USDA Natural Resources Web Soil Survey 11/16/2015 Conservation Service National Cooperative Soil Survey Page 3 of 3 11. Conditions and Requirements Summary CORE REQUIREMENTS - SECTION 1.2 OF KCSWDM 1.2.1 CORE REQUIREMENT #1: Discharge at the Natural Location Under existing condition, the site sheet flows westerly to Grant Avenue South. The low point of Grant Avenue South is located near the northwest corner of the site where there are two type 1 catch basins at both sides of the street to collect street runoff. The street drainage system drains to an existing storm manhole (SDMH#1) near the northwest corner of the site. SDMH#1 has a 15" CMP outfall pipe that discharges westerly to Thunder Hills Creek. Under developed condition, same drainage pattern will remain. The outfall of the onsite storm system will be connected to SDMH#1, other than that, the offsite storm system will remain unchanged. 1.2.2 CORE REQUIREMENT #2: Off -site Analysis This core requirement has been addressed in Section III of this report. 1.2.3. CORE REQUIREMENT #3: Flow Control Per SWDM section 1.2.3.3 and 5.2, Flow Control BMPs are required for the onsite development. Since the site is a PUD with individual lots, the project is required to provide BMP for minimum 10% of the individual lot areas. The feasibility and applicability of full dispersion is studied first, the study found full dispersion is not suitable for this site to fully disperse the new impervious areas and new non-native pervious areas because long native flow path is not available due to the high impervious area ratio. Full infiltration is also not suitable for this site because onsite soil is till soil (Alderwood gravelly sandy loam, 6 to 15% slopes, AgC and 15% to 25% slopes, AgD) according to City of Renton Soils Map. The following flow control BMPs are used: 1. Native growth retention area (TRACT C, 2,595 square feet, counted as pasture area). Impervious area credit allowed by this BMP is 2,595/3.5 = 741 square feet. 2. Pervious concrete walkway for all onsite sidewalks (8,976 square feet, credited as 50% impervious area, 50% grass) 3. Grasscrete pavement for vault maintenance access driveway (1972 square feet, credited as 50% impervious area, 50% grass) 4. Perforated tie lines for downspout connections. (no credit) Total impervious area treated by flow control BMPs is 11,689 square feet which is approximately 32.8% (> 10% of the total lot areas of the 36 zero lot line lots (total 35,630 square feet which is 3,563 square feet). Final signed Flow Control BMP Covenant is required prior permit is issued and will be recorded with the PUD Plat map. Onsite flow control facility is provided by a combined detention/wet vault to provide the required Duration standard forested site conditions flow control. 1.2.4 CORE REQUIREMENT #4: Conveyance System The new conveyance piping will be installed as needed. The new conveyance piping has been checked to confirm compliance with chapter 4 of the 2009 KCSWDM. Per City Amendments to the 2009 KCSWDM Section 1.2.4.1: 1. New pipe system shall be designed with sufficient capacity to convey and contain (at the minimum) the 25-year peak flow with minimum 6 inches of free board, assuming developed conditions for onsite tributary areas and existing conditions for any offsite tributary areas. 2. Pipe system structures may overtop for runoff that exceed the 25-year design capacity, provided the overflow from a 100-year runoff event does not create or aggravate a severe flooding problem or severe erosion problem as described in Core Requirement #2. Any overflow occurring onsite for runoff events up to and including the 100-year event must discharge at the natural location for the project site. In residential subdivision, this overflow must be contained within an onsite drainage easement, tract, covenant, or public right-of-way. 3. The upstream end of a pipe system that receives runoff from an open drainage feature (pond, ditch, etc.) shall be analyzed as a culvert. The property south of the site (Heritage Village Condominiums) have their own drainage system to intercept runoff before it reaches the site. For the two properties east of the site (parcels 739900-0060 and 739900-0070), the roof and front yards of these properties drain to the Jones drive SE drainage system and the back yards of them sheet flow to the site (approximately 9,600 square feet). The property north of the site slopes westerly to Grant Avenue South parallel with the site. The properties west of the site are located at elevations lower than the site. An intercept storm will be installed near the east property line of the site to collect the upstream offsite runoff from the east. The new conveyance system is designed to convey and contain the 25-year peak flow with 6 inches of free board and the 100-year peak flow and thus meets the requirements listed above. KCBW is used for Back water analysis following the requirements of City Amendments to 2009 KCSWDM 4.2.1.2 and designed for the 100-year peak flow. The offsite upstream runoff from the back yards of the two east adjacent properties is also drained to the onsite combined detention vault, the orifices of the control structures inside the vault are designed to bypass this offsite runoff. The wet vault and StormFilter manhole are designed to also treated this additional offsite upstream runoff. 1.2.5 CORE REQUIREMENT #5: Erosion and Sediment Control Erosion control will be installed as necessary for the frontage improvements and the on - site improvement. See Section 8 of this report for temporary sediment trap sizing calculations. 1.2.6 CORE REQUIREMENT #6: Maintenance and Operations M Any necessary maintenance of the onsite drainage system will be the responsibility of the property owner and manager. 1.2.7 CORE REQUIREMENT #7: Bonds and Liability Necessary bonds will be provided at the time the building permit plans are approved and the construction started. 1.2.8 CORE REQUIREMENT #8: Water Quality A treatment train of combined detention/wet vault and StormFilter manhole with CSF cartridges is used to provide the required Enhanced Basic treatment for the project site and upstream offsite runoff from the back yards of two east adjacent properties. The project site includes onsite improvement and frontage improvement along Grant Avenue. Due to the topographic of the site, the offsite improvement does not drain to the onsite combined detention wet vault and StormFilter manhole system but water quality treatment is not required for the sidewalk improvement along the Grant Avenue frontage because sidewalk is not counted as pollution generating impervious area. 10 SPECIAL REQUIREMENTS - SECTION 1.3 OF KCSWDM 1.3.1 Special Requirement #1: Other Adopted Area Specific Requirements No other area specific requirements are applicable. The site is not within a CDA, MDP, BP, SCP, SWCP, LMP, FHRPU or SFDP. 1.3.2 Special Requirement #2: Flood Plain / Floodway Delineation Not applicable to this site. There is no flood hazard area in the site. The site is not within a floodplain or floodway. The site is not subject to inundation by the base flood or channel migration. 1.3.3 Special Requirement #3: Flood Protection Facilities Not applicable to this site. There is no flood hazard area in the site. The site does not rely on any flood protection measures. 1.3.4 Special Requirement #4: Source Controls The site is subject to water quality source control. Dumpsters and recycle bins will be stored inside the garages of each units. 1.3.5 Special Requirement #5: Oil Control The estimated ADT of the developed site is approximately 290. The threshold for high - use site is ADT of 100 or more vehicles per 1,000 square feet of gross building area. Gross building area of the site is approximately 39,806 square feet. The threshold for high -use site is ADT of 3981 vehicles. Thus, ADT of the site will be less than the threshold ADT. Oil control is not required. The flow control riser tees with orifices in the flow control structures and the StormFilter manhole will provide enough treatment for oil control, no extra treatment is required. City of Renton Special Requirement #6: Aquifer Protection Area Not applicable to this site. The site is not located in the Aquifer Protection Areas (zone1, zone 1 modified and zone 2) shown on the City of Renton Aquifer Protection Zones Map. Ill. Off Site Analysis 15 Task 1 Study Area Definition and Maps The site is located on the east side of Grant Avenue South, two parcels north of South 18th Street. The address of the site is 1600 Grant Avenue South. The parcel number of the site is 202305-9052. The onsite area is 2.11 acres. The total project site area is 2.17 acres including the offsite improvement along Grant Avenue South. The site is located in the Thunder Hills Creek drainage subbasin of the Black River Drainage Basin. See attached Site Map and Topographical Map. Task 2 Resource Review The following resources have been reviewed for existing /potential problems in the study area. 1) Adopted Basin Plans Exhibit C, City of Renton Shoreline Master Program Update Restoration Plan, prepared by City of Renton, dated March, 2010 http://www.ecy.wa.gov/programs/sea/shorelines/smp/mycomments/Renton/restoration lap n.pdf 2) Finalized Drainage studies None. 3) Basin Reconnaissance Summary Reports and 1"=400' scale problem summary maps City of Renton Shoreline Master Program, Final Shoreline Inventory and Analysis, prepared by City of Renton, dated March, 2010 http://rentonwa.gov/uploadedFiles/Business/EDNSP/planning/2.3%20FINAL%20Invento ry%20(3-31-10).pdf?n=2007 4) Critical Drainage Area maps Do not apply in the City of Renton per City of Renton Surface Water Design Manual. 5) Sensitive Area Folio See attached Sensitive Area Folio. 6) DNRP Drainage complaints and studies None. 7) Road drainage problems There are no road drainage problems within the study area. 8) U.S. Department of Agriculture, King County Soils Survey The King County Soils Survey map and City of Renton Soils Map show Alderwood soil on the site (AgD on the west portion of the site and AgC on the east portion of the site). See attached Soils map. 9) Wetland Inventory There is no wetland on the site and its adjacent areas. 10) Migrating river studies There is no migrating river within the study area. 17 1 G �_ 9��� ■�: �Gi�IIL �° f �-i � S' ��� n � � E , � "� i 1 � � � ' � .� II, �tiZ ( I� U I r J i �" ; mµ �y4nII ... � ` I � P Z 3 k /� ` � ��� .�s� � e Rrva _ _ � e� o .� 'U� n S ®®3 ; E a FY� m \e �� € -� % L `lam/fin ,.� �_, e i "fin' `,.. �®®® � , �,' D L _o n6 �9 � Y ... - ��1,,. �a a� � �, �,� � •� - � �� �. _ �. ®� �• "���DD�LIIJLIL �LJLIIJ _ � ® � o� aow I(' 9 `L ®�� �, - ,,, ® �� _ ,,. � - --- ��� ---- DO a __ 1 J 4 � l .w. •� -D .� ''� o .� i b rl '¢ V 0 a -a �� .� .o ,.. ''® � -� ®® � a �o �� � � . II��I`'I�'I ��IIf ®,,,� � a !, �,���, ','',;' ', I;;!I', I; ;;','',';;', I', I' i 1, ® a �° ,� �� d � L I w. moo. R ^� ^� W '�� V N (n O N O U z E� �o �� = o �� -� �-'E c c� d OQ�jN 3 �'�pT = � � � � U E � Q o — E c ° y �Ns�� ac��ria` o 0 J MERCER a. ISLAND T SOREN NEWCASTL COAL CREEK ......... - - - - -• TRIBUTABIES S DA 9A SK R- ---------- - --- -- -------- C3 RENTO` AL J; 11 SE Qp M 14 M11-A LAKE DESTREV01 4 XEN-r 'f&1A11;E.R Renton Municipal Code Creeks For Reference On Roads Rivers City Boundary I Inch = I Mile -- I I Wetlands Lakes Municipality Boundaries IRenton Wetlands Task 3 Field Inspection There is a single family house (built 1946) on the west portion of the site near the Grant Avenue South. The house will be demolished and removed for the proposed development. The remainder of the property is covered with grass with some scattered trees. The site is hilly with average slope of 11 % slopes westerly toward Grant Avenue South. There is no sensitive area on the site. Upstream: The property south of the site (Heritage Village Condominiums) have their own drainage system to intercept runoff before it reaches the site. The property north of the site slopes westerly to Grant Avenue South parallel with the site. The properties west of the site are located at elevations lower than the site. For the two properties east of the site (parcels 739900-0060 and 739900-0070), the roof and front yards of these properties drain to the Jones drive SE drainage system and the back yards of them sheet flow to the site (approximately 9,600 square feet of till grass). Total upstream drainage area flows to the site = 9,600 sf. = 0.22 acres (till grass). Downstream: Under existing condition, the site sheet flows westerly to Grant Avenue South. The low point of Grant Avenue South is located near the northwest corner of the site where there are two type 1 catch basins at both sides of the street to collect street runoff. The street drainage system drains to a storm manhole (SDMH#1) near the northwest corner of the site. SDMH#1 has a 15" CMP outfall pipe that discharges westerly to Thunder Hills Creek. See attached City of Renton AS -built drawing R-123402. The 0.25-mile downstream point is located at the Thunder Hills Creek. The 1 mile downstream point is located at the city storm drainage system that drains to Springbrook Creek. No capacity problem, erosion problem and water quality problem were found within 0.25 miles downstream of the site in the field inspection. 36 a^V ylbl U + U m S Id yl£11 ® + �i • iti+e i In Ali 3S 1D ■■y,■ U ■ S anyaa f■y 3 uaapjagy U w ■ °Ja iu • i a}en! 11J ^s 1 qy " ■� a _ . ■ w to w �f^�jJO� G 36 Id yl n � ( J L 3 � Ilob W L y l� uOou!g S R S Id (3 �—^ v ■ a ■ a long loou!-I ■ ■ on Alk uua>j SG6 �J■ ++ / �- Gad ■t4' ►■ °fie In�i ■ y 3S In •i N ■y Q� i +df 1■ ,� 3S lQ uOr ;in o souor ul10Lj ■'■i +LU �°� u� a9 ■�S+ AV sauo(` S N/ sauor ■i.�,� �, ■+■AV q o ■ d� Hi�� In S �� + UPry aFii •' g any;ue�� ■ S Jr iwh■—■ ' 3 Sany}uej� S an o;uaLl ��� p Q p A..v °Fay • 1 � 2 • P � '`r w` �n In a� + \ ' � 5 ■ °� : �V'" ■ s ■ CD d i+ Pe r■ . In in In I ® ■ In• 6� + Spy ■�®iy� ui ` od Benson : d�r+� ■ "+�.Y"~ i� 4 / AJO i ■i ■ ®+ +� ® ® ® ■ + ■ir-�,a■i ■ ■ + + + r� i ■,r�� f". nl� r» •^--+i ■ ■ate ��a ■ j �J In Ae, EL �n y �+ + ny spay;Iwg n _ ■■�■ ■w�i■i •■ ■ ■ b Jo 0 ' S any spay;+ S In In • In In S an '',■1 ■� .��.� San }�oro�}IyM V swoW � d Q U1 �jTOD jol � NII { + J � Y ■■ ■—■' — , - IN t no-- No —mm-4 r P� [�m lk� y■� [ �- •;, f • ■ �;■ : ■ cD loll �i # ny spay;IwS n 1 L ■rm ■�ml r` • ■ �10®1:: o ''S any spay;• S '■rt 1 # # n . slyoW a S any Sao `6 ■ S and ®t■ ®..., S an }JoM;lyM �1o9/p #}iw ■ ■■ Eff m _ �® • dny nil 4 ® o ■ ev® ■^--.� . # ■ rn a # ■ QNil f ■ 4 1 ake ■ ■ 1 �i ■ °i #r ■ t�3 ■ ® c Pll EB SR 16 ■ ®,■ E Valley Rd i ■ ■iME r ■ J01 on n n ■ (} ■ ■i > 4 _ ®® I® ■M IIII no .. ® a ■IN �=s � #ul ® i MSanyui,La San .■ ■ # � ■ �t CIA i AI'II rEss. ■■ .-__ ■ # eoa ---�®®■■ a ® �■ e aS # ®m � L ■`.a ■■ ■ iL Q_ Yiy Yi ■ In �ij �O 11yy{ t■ 1v^i L _ ✓ Z� wn # ' �. .00 a a N.g � t•il r� ■ ■ to It I -J) , 777 too •.■4..i ■r - ■WY� f #�W#=rYi#DIY#■■L{�)Jli�f . �A�6Nr®i®— P-� ■■ f ■t �m O Asa t # m 1■i�• `�P m ®. 0 as Task 4 Drainage System Description and Potential Problems There are no unsolved existing and potential drainage problems within 0.25 mile downstream of the site. Task 5 Mitigation of Existing or Potential Problems There are no unsolved existing and potential drainage problems within 0.25 mile downstream of the site. For onsite improvement, for the onsite improvement, new plus replaced impervious area is approximately 1.38 acres, new pervious area is approximately 0.73 acres. Flow control BMPs, Native growth protection area (2,595 sf.) and pervious concrete sidewalk (9,291 sf.) are used to treat approximately 33.4% of the 36-lot areas. A combined detention/wet vault is used to provide the required Duration standard forested site conditions flow control and a treatment train of wet vault and StormFilter manhole with CSF cartridges is used to provide the required Enhanced Basic water quality treatment. Treated runoff will be discharged to its natural discharged location (SDMH#1 at Grant Avenue South). An intercept storm will be installed near the east property line of the site to collect the upstream offsite runoff. The offsite upstream runoff from the back yards of the two east adjacent properties is also drained to the onsite combined detention vault, the orifices of the control structures inside the vault are designed to bypass this offsite runoff. The wet vault and StormFilter manhole are designed to also treated this additional offsite upstream runoff. For offsite frontage improvement, as discussed in Section 1 of this report, the offsite improvement will drain to the existing Grant Avenue storm system bypassing the onsite flow control and water quality treatment facility, no additional flow control or water quality treatment is required. The proposed development will not create any adverse impact on the downstream drainage system. 19 IV. Flow Control and Water Quality Facility Analysis and Design m Part A Existing Site Hydrology Duration standard forested site conditions flow control requires matching developed flow duration from 50% of pre -developed 2-year peak to full 50-year peak and matching peak discharge rates of developed 2 and 10-year peaks with the existing 2 and 10 year peaks. Existing site condition is forest condition per City of Renton Flow Control Application Map. Onsite and offsite improvements Scale factor = 1.00 Total onsite area = 2.11 acres (assume till forest) Total offsite area (Grant Avenue South frontage) = 0.06 acres (assume till forest) Total project site area = 2.17 acres (assume till forest). Upstream offsite area = 0.22 acres (till grass, from back yards of the two east adjacent properties) Total drainage area = 2.39 acres 40. Land Use Summary r-Area Till Forest! 2.17 acres Till Pasture= 0.00 acres Till Grass' 0.22 acres Outwash Forest; 0.00 acres Outwash Pastured 0.00 acres Outwash Grass: 0.00 acres Wetland 0.00 acres Imperviousl 0.00 acres File for computed Time Series [.TSF] X 41 Flow Frequency Analysis Flow Frequency Analysis Time Series File:pre.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.155 2 2/09/01 18:00 0.045 7 1/05/02 16:00 0.124 3 2/28/03 3:00 0.007 8 3/24/04 19:00 0.071 6 1/05/05 8:00 0.120 4 1/18/06 20:00 0.106 5 11/24/06 4:00 0.210 1 1/09/08 9:00 Computed Peaks Existing peak flows Q2y = 0.071 cfs Q10y = 0.124 cfs Q100y = 0.210 cfs Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) Period 0.210 1 100.00 0.990 0.155 2 25.00 0.960 0.124 3 10.00 0.900 0.120 4 5.00 0.800 0.106 5 3.00 0.667 0.071 6 2.00 0.500 0.045 7 1.30 0.231 0.007 8 1.10 0.091 0.192 50.00 0.980 22 0 rn co 6 W U) W 2 O z O (- W V Q J n H z Q N CD (- W W Cn OFFSITE FRONTAGE AREA = 0.06 ACRES (TILL FOREST) I � I I ' 25'007' . 1 5.p' 0 �.�61, UPSTREAM TRIBUTARY AREA = 0 . 2 2 AC. C 0 10 20 30 TOTAL ONSITE AREA = 2.11 11 AC. (TILL FOREST) ilri� Tr- - (TILL 6.50 6383' GRAPHIC SCALE GRASS) SCALE-1•-W Found Brass Mon. W/Punch In Conc. in Case 7-16-05 R=200.62' r L=55.53' Found Brass ...�� -- Mon. W/Punch In Conc. in Case 7-16-05 g i = - \ � _SDMH ` 1 I 'CB 30 M -4 V _ SURVEYOR \ �_ ��� � 2'• - LEGAL DESCRIPTION tiURVE ORI TREE TABLE I 11M GRIFFIN AN UNDIVIDED ON -HALF INTEREST IN THE FOLLOWING DESCRIBED PROPERTY: TYEE SURVEYORS III TYPE SIZE - DRIPLINE PORTION OF THE NORTHEAST QUARTER OF THE SOUTHWEST QUARTER DF 10007 GREENWOOD AVE. N i ALDER iBk16 SOMH-2 "" 75 SECTION 20, TOWNSHIP 23 NORTH, ROUGE 5 EAST, W.M., IN KING COUNIM I SEATTLE, WA 98133 2 IE? dr14" 7V WASHINGfON, DESCRIBED AS FOLLOWS: 3 1B"WV' 50' PHONE: (206) 525-3660 4 �� �„ W. BEGINNING ON THE EAST LINE OF SAID SUBDTV SIDN AT A POINT WHICH IS \ SOUTH 00'OB'49' WEST 475.79 FEET FROM THE NORTHEAST CORNER THEREOF; 5 CHERRY 16" dr14" 40' THENCE NDRTH woe;'49" EAST 158.00 FEET; 6 ALDER 12'•, B", B" 50' THENCE WEST PARALLEL WITH THE NORTH LINE OF SAID SUBDIVISION 654.50 7 1B" iB•• ID" 65, FEEP Found Brass Mon. W/"X" B DECIDUOUS 9 MAPLE 1W. 3 X 6" 18", 12" 10", 1D", 14" 2D' W. THENCE SWIM 26'1B'S7" EAST TO THE INTERSECTION WITH A LINE EXTENDING WESTERLY THROWN THE SAID POINT OF BEGINNING AND PARALLEL WITH THE SYMBOLS LEGEND: In Con[. in Case 7-16-05 ID MAPLE 11 LOCUST ID" 2X74", 2X12", 6X1D", 3XB", B" 30' 10V NORTH LINE OF SAID SUBDIVISION; THENCE EAST ALDNG SAID EXTENDED LINE TO THE POINT OF BEGINNING: EXCEPTION THEREFROM A STRPI OF LAND 30 FEET WIDE, PARALLEL WITH AND I ❑ CATCH BASIN ` 13 FIT II, 12" aw ADJDINING THE WESTERLY LINE OF SAID TRACT, FOR ROAD PURPOSES: I .p. POWER POLE(AS NOTED) EXISTING STORM STRUCTURES IN GRANT AVENUE ,%` 1 14 " 12' 3V SITUATE IN THE COUNTY OF KING, STATE OF WASHINGTON. CB-1 SDMH-1 TYPE-2, SOLID LIO 1 - 1S " 16 " " 12" 12" 25' 30' TAX PARCEL # 2D23059052 °0°0°°° RDCKERY RIM = 293.7 RIM = 294.5 I 17 MAPLE 12" 45' STORM DRAIN MANHOLE 12' CMP S - 290.5 12" CMP N = 290.0 1 1B " 12" TELEPHONE RISER 8" CPM W = 290.8 12" CMP NE = 289.9 19 " if' 40• MERIDIAN GENERAL NOTES 15" CMP W = 286.6 'CB-5 20 ALDER 13" 35' ES WATER METER RIM 2 293.9 12• CMP SW = 287.1 �, I „ .. 21 '• ,. 23 " 13" 14,. 14" 25' 40 40' ASSUMED DATUM i. THE INFORMATION DEPICTED ON THIS MAP REPRESENTS THE RESULTS OF A SURVEY MADE ON THE DATE INDICATED AND CAN ONLY BE CONSIDERED AS INDICATING THE GENERAL CONDITION EXISTING AT THAT TIME WATER VALVE 8" CMP E = 291.3 SDMH-2 TYPE-2, SOLID LIO 24" '• 14" CONIFER(AS NOTED) RIM = 313.9 I 25 •• 14" 3p• 30' NAVD 86 BASED ON IN THE EYIOENCE�OF�UTNLIDTI6 (m6P WERE ]IENT�COVERS, CB-3 36" CMP N = 304.4 / I 26 " 14" 30' CONTOUR INTERVAL = 2' MMICS�SAW LIDS ErcJ THE CONTRACTOR SWILL VERIFY THE EXACT LOCATION, ELEVATION f� �, j DECIDUOUS(AS NOTED) RIM = 307.5 12'• CMP SE = 308.5 27 •• •• " 14" 30' AND SIZE OF EXISTING UTILITIES PRIOR TO CDNSIRUCTION. 8" CMP = 305.3 CURVE 2e 14" 30' EQUIPMENT & PROCEDURES x FENCE LINE AS NOTED SDMH-3 TYPE-2, SOLID LID =5149'25' 29 30 MAPLE 14" 14" 21Y55, 55' 3. TREE SIZES WERE LOCATED do SPECIES DETERMINED RA THE BEST OF OUR ES TWEE SURVEYORS DOES NOT WARRANT THE ACCURACY CB-4 RIM = 313.9 _ / R=125.00' 31 14• 5G A S' ELECTRONIC TOTAL STATION WAS USED FOR THIS FIELD &Y. SPECIESSHOWN ANY EKED TO BE SIZE CI ICAL RIM - 307.4 CMP S = 3304. L=113. �• T=60.73 32 ALDER 13" 30' TRAVERSE SURVEY. ACCURACY MEETS OR EXCEEDS WAC. 332-130-090. CRIB HOULD BE VERED BY AN. �T BORIST. 12 CMP W - 303.2 12" CMP E = 303.2 12" 12'� CMP SW = 304.4 / 33 CHERRY 34 u.OrR IS, 16" 50, 40' 4. THIS MAP DOES NOT PURPORT TO SHOW EASEMENTS OF RECORD, IF ANY. / SDMH-4 TYPE-2, SOLID LIO 35 " 18' 35 BENCHMARKS S. NO PROPERTY CORNERS WERE SET IN CONJUNCTIDN WITH THIS SURVEY. Q //� R-��,/ OO2 CB-5 RIM = 307.9 " 1B' 45' ORIGINAL BM; FOUND BRASS DISK IN CONCRETE IN THE RIM = 309.6 8" CMP SW = 303.45 37 38 " 1B" 2D" 45' 45' INTERSECTION OF S 18TH ST AND GRAND AVE S. WGS POINT DESIGNATION : RENT7B7. 8" CMP E = 307.5 12" CMP NE = 303.1 39.1 2W 50' ELEV. _ 317.S7 APPROVED FOR CONSTRUCTION 8" CMP W = 307.5 12" CMP NW = 302.9 40 " '; 41 •• �; V 1' IBM - A: MSG NAIL IN SEAM 2' WEST OF TOP BACK CURB SUBJECT TO ERRORS AND OMISSIONS 42 FIR V. 35• 35' ON WEST SIDEWALK OF GRANT AVE S. ON 43 ALDER 24" 45' ELEV.308.B7 EXISTING SEWER STRUCTURES NEAR GRANT AVENUE 44 " 24•' 50' TBM - B: SET HUB + MAG NAIL 2W +/- E OF SE CORNER OF BY: DATE: . SSMH-2 TYPE-2, SOLID LID 45 " „ 48 " 24• 24" 50, 40' -TREE IS DYING- HOUSE EL. a 31B.93 ELEV. RIM = 315.6 47 FIR 24" 35' BY: DATE: . 8•' CONC IN N 48 " " 24" 35• 8" CONC IN E BY: DATE: 8" CONC OUT SW 50 ALDER 3v 5V . CTR CHANNEL = 303.4 51 ASH S2 CEDAR 53 CHERRY 38 3s" 38" 7S' 50, 60' BY: DATE: . „ TIac6fi r�r�J gDesign, L L Civil Engi;r" inn a Pianniny ;;an:.vl't=iraaz; T. GRIIFFIN 1"-20' 'I"am_ d1 CITY OF GRANT PLACE TOWNHOMES 2016-1 J. HOPPERRENTON 2 SECOND ROUND CITY REVIEW COMMENTS JF 4 JH E MARSHAL 1FIRST ROUND CITY REVIEW COMMENTS AL U242 = -J. HOPPER Planning/Building/Public Works Dept. EXISTING CONDITIONS NO. REVISION BY DATE APPR f° "m0O Y CO2 Ln DO DO 0 0 0 Ln Q J I Part B Developed Site Hydrology Onsite improvement with upstream offsite runoff Under developed condition, onsite runoffs and upstream offsite runoff from the east will be collected and conveyed to the onsite detention system. Onsite impervious area calculation: Roofs of 8 new townhomes = 22,736 sf. Public alley, driveway and parking = 24,567 sf. Asphalt vault access driveway = 571 sf. Grasscrete vault access driveway = 1,972 sf. Pervious concrete sidewalk = 8,976 sf. Total impervious area = 58,822 sf. = 1.35 acres. (roof, driveway, walkway, etc. before apply flow control BMP credits) The 8,976 sf. of pervious concrete sidewalk and 1,972 sf. of grasscrete vault access driveway can be credited as 50% impervious area, 50% grass. After apply the credit, they can be counted as 5,474 sf, of impervious area and 5,474 sf. of till grass. The 2,595 square feet Tract C is set aside as Native Growth Protection Area, other than the removal of dangers trees, this area will remain undisturbed. At least one existing 12" big leaf maple will remain, and 10 new trees will be planted in this area. This area will be counted as till pasture under developed condition. Total 741 square feet of impervious area (2,595/3.5 = 741) can be credited by this BMP. After apply flow control credit Total onsite impervious area = 58,822 — 5,474 — 741 = 52,607 sf. = 1.21 acres Total onsite area = 2.11 acres Total onsite pervious area = 2.11 — 1.21 = 0.90 acres Native Growth Protection Area Tract C = 2,595 sf. = 0.06 acres (till pasture) Onsite till grass = 0.90 — 0.06 = 0.84 acres Upstream offsite drainage area from the east = 0.22 acres (till grass) Total drainage area to the vault = 2.11 + 0.22 = 2.33 acres. Total impervious area to the vault = 1.21 acres Total till pasture to the vault = 0.06 acres Total till grass to the vault = 1.06 acres 23 Land Use Summary a_.Are .e.,_._ Till Forests 0.00 acres Till Pasture 0.06 acres Till Grass, 1.06 acres File for computed Time Series [.TSF] Flow Frequency Analysis Time Series File:dev.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.391 5 2/09/01 2:00 0.308 8 1/05/02 16:00 0.472 2 2/27/03 7:00 0.321 7 8/26/04 2:00 0.390 6 10/28/04 16:00 0.414 4 1/18/06 16:00 0.467 3 10/26/06 0:00 0.803 1 1/09/08 6:00 Computed Peaks -----Flow Frequency Analysis ------- - - Peaks - - Rank Return Prob (CFS) Period 0.803 1 100.00 0.990 0.472 2 25.00 0.960 0.467 3 10.00 0.900 0.414 4 5.00 0.800 0.391 5 3.00 0.667 0.390 6 2.00 0.500 0.321 7 1.30 0.231 0.308 8 1.10 0.091 0.693 50.00 0.980 Developed condition peak flows before detention: Q2y = 0.390cfs Q 10y = 0.467 cfs Q100y = 0.803 cfs 24 Offsite improvement Counted as bypass areas Under developed condition the right of way frontage improvement will create 1,200 square feet (0.03 acres) new plus replaced impervious area. Total offsite bypass area = 0.06 ac. Impervious area = 0.030 ac. Pervious area = 0.030 ac. (till grass) Land Use Surma yr ,--Area Till Forest! 0.00 acres Till Pasture, 0.00 acres Till Grass} 0.03 acres Outwash Forest, 0.00 acres Outwash Pasture� 0.00 acres Outwash Grass! 0.00 acres Wetland! 0.00 acres Impervious, 0.03 acres Flow Frequency Analysis Time Series File:offsite.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.010 5 2/09/01 2:00 0.008 7 1/05/02 16:00 0.012 2 2/27/03 7:00 0.008 8 8/26/04 2:00 0.010 6 10/28/04 16:00 0.011 4 1/18/06 16:00 0.012 3 10/26/06 0:00 -----Flow Frequency Analysis ------- - - Peaks - - Rank Return Prob (CFS) Period 0.020 1 100.00 0.990 0.012 2 25.00 0.960 0.012 3 10.00 0.900 0.011 4 5.00 0.800 0.010 5 3.00 0.667 0.010 6 2.00 0.500 0.008 7 1.30 0.231 25 0.020 1 1/09/08 6:00 0.008 8 1.10 0.091 Computed Peaks 0.018 50.00 0.980 Developed condition offsite bypass peak flows: Q2Y = 0.010 cfs Q1 Oy = 0.012 cfs Q1 OOY = 0.020 cfs The hydrograph of the onsite detained runoff (detention vault release, include the 0.22 acre upstream tributary area, rdout.tsf) will be added with the hydrograph of the offsite bypass area (Grant Avenue South frontage improvement, offsite.tsf). The combined hydrograph (dsout.tsf) is used to compare with the existing hydrograph of the total combined site (including onsite area 2.11 acres, upstream tributary area 0.22 acres and Grant Avenue South frontage improvement area 0.06 acres, total 2.39 acres, pre.tsf) at the point of compliance at existing storm manhole SDMH#1 at Grant Avenue South to meet the requirements of Level 2 detention. M 0 m C'') O W F- U ¢ J z CC CD F- W W U) ---------------------- ------------------- \ /TI E, Unu A \ oa A PA � 15'S1'32' R=200.62' +. LOT AREA TABLE 1 1,076 SF 2 846 SF 3 1,025 SF 4 846 SF 5 1,076 SF 6 1,076 SF 7 846 SF 8 1,025 SF 9 1,076 SF 10 1,076 SF 11 846 SF 12 1,025 SF 13 1,076 SF 14 1,083 SF 15 851 SF 16 1,032 SF 17 851 SF 18 1,083 SF 19 1,083 SF 20 851 SF 21 1,032 SF 22 851 SF 23 1,083 SF 24 1,076 SF 25 846 SF 26 1,025 SF 27 1,076 SF 28 1,076 SF 29 846 SF 30 1,025 SF 31 1,076 SF 32 1,076 SF 33 846 SF 34 1,025 SF 35 846 SF 36 1,076 SF TOTAL 35,630 SF MIN. 846 SF MAX. 1,083 SF AVC. 990 SF 1 12 I 3 I II 4 I 5' 1,076SF1846SFI1 025SF ,W_SF11 0765 �.,...__...,... e _,. I I T, - _�a- I I I I 36 1 35 1 34 1 33 1 32 1,076SF 1846SFI1,025SFi 846SFI1,0765 :0 Y1711T, 0; 6 ' 7 8 9 11 076SF ' 846SFI1,025SF I 1 076SF I SD SC pa ._.--_ 1 a . 1__ a I .. 1 1 1 I I 31 1 30 1 29 1 28 1.076SF;1,025SFTB46SF,1,076SF - 544.56' - s 89ro9'24' w 10 11 12 13 11,076SF1846SFf1,025SF11,076SF1 1 1 1 27 1 26 1 25 p 24 1,076SF;1,025SF; 846SF 11,076SF 14 1 15 1 16 1 17 1 18 1.073SFi843SF11,022SF1843SFj1,073SF SITE Ln 00 1 SCALE: 1'=1000' CD 1 1 20 11I 1 - SHEEP INDEX.- 00 8435d 1 022SF 843SF' 1,073SF 1 C01 -COVER Ln 1 073SF CO2 - EXISTINC CONDITIONS I CO3 - SITE PLAN AND HORIZONTAL CONTROL PLAN ¢ C04 - CONDITIONS OF APPROVAL � TRACT B - - (INGRESS, EGRESS, UTILITY, AND OPEN I I SPACE) 12,453SF I I I I i1w I N I $; •- , / w - ..� g S&- I i� 1 - TRACT C (TREE PRESERVATION) 2,595SF C06 - TEMPORARY EROSION AND SEDIMENT CONTROL PLAN C07 - TEMPORARY EROSION AND SEDIMENT CONTROL NOTES AND DETAILS C08 - CRAOINC ROADWAY AND DRAINAGE PLAN C09 - ROAD AND STORM PROFILES C10 - VAULT PLAN _I C11 - VAULT SECTIONS - - - _ _ C12 - STORMFILTER MANHOLE DETAILS e C17 - COMPOSITE UTILITY PLAN LEGEAD: \ SD STORM MAIN LINE - - - - - - - - - - - STORM TICHT LINE -" ® TYPE 1 CATCHBASIN Q TYPE 2 CATCHBASIN 9TE INFORMATION- ® STORM CLEANOUT SS SEWER MAIN LINE ADDRESS: 1600 CRANT AVE S SIDE SEWER LINE PARCEL NUMBER: 202305-9052 IN 1 0 ZONINC: RM-F SEWER MANHOLE PARCEL AREA: 92,051 SF (2.11AC) 1 SEWER CLEANOUT OISTURBED AREA: B9,451 SF (2.05 AC) WATER MAIN LINE EXISTINC IMPERVIOUS AREA: 3,900 SF (0.09 AC) W I GROSS NEW IMPERVIOUS AREA: 58,866 SF (1.35 AC) WATER SERVICE LINE NET NEW IMPERVIOUS AREA: 54,966 SF (1.26 AC) 0 WATER METER �+ WATER TEE I I H WATER VALVE BUILDING AREAS: BUILDING 1 3,2B4 SF *__0 FIRE HYDRANT ASSEMBLY BUILDING 2 Z723 SF WATER BENDS BUILDINC 3 Z723 SF BUILDINC 4 31284 SF /[ WATER CAB W/ 8.0. BULDNC 5 3,284 SF CL CURVE UTILITY LINES BUILDINC 6 Z723 SF 0=51'49'25' BUILDING 7 2,723 SF / R=125.00' 312 2-FOOT CONTOUR LINE BUILDING 8 3,284 SF Ala / L=113.0§' _ _ TOTAL 24,028 SF T=60.73 310 10-FOOT CONTOUR LINE / oGmGCOGOCm]Om ROCKERY BUILDINC COVERACE: 26% PROPERTY LINE UTILITY PURVEYORS: - - LOT LINE R.O.W. LINE WATER CITY OF RENTON - - - - - EASEMENT LINE SEWER CITY OF RENTON STORMWATER CIYT OF RENTON CURB LINE BUILDINC LINE CLIENT/ DEVELOPER: CML ENG JNEER: SURVEYOR: H JOE HOPPER nM CRIFFTN TRACT �9,206 �SABLE F 0.44 AC TRACT 8 12,453 SF 0.29 AC TRACT C 2,595 SF 0.06 AC TOTAL 34,254 SF 0.79 AC SATWNT SING A SKYLINE PROPERTIES, INC. PACIFIC ENGINEERING DESIGN, LLC TYEE SURVEYORS 50 116TH AVE SE, SUITE 120 15445 53RO AVE S., SUITE 100 10007 GREENWOOD AVE. N 8ELIEWE, WA 98004 SEATTLE, WA 98188 SEATTLE, WA 98133 PHONE: (206) 431-7970 PHONE: (206) 525-3660 F.PN M.HQ,00 p5 of SHi F C18 -WASTEWATER AND WATER UTILITY PLAN C19 - WASTEWATER AND WATER UTILITY PROFILES C13 - DETAILS C14 - DETAILS C20 - OETATLS C21 - DETAILS 30 0 10 zo so so C16 - TREE RETENTION PLAN L100-L101 LANDSCAPE PLANS L200-L202 IRRIGATION PLANS GRAPHIC SCALE SATWNT SING A SKYLINE PROPERTIES, INC. PACIFIC ENGINEERING DESIGN, LLC TYEE SURVEYORS 50 116TH AVE SE, SUITE 120 15445 53RO AVE S., SUITE 100 10007 GREENWOOD AVE. N 8ELIEWE, WA 98004 SEATTLE, WA 98188 SEATTLE, WA 98133 PHONE: (206) 431-7970 PHONE: (206) 525-3660 F.PN M.HQ,00 p5 of SHi F C18 -WASTEWATER AND WATER UTILITY PLAN C19 - WASTEWATER AND WATER UTILITY PROFILES C13 - DETAILS C14 - DETAILS C20 - OETATLS C21 - DETAILS 30 0 10 zo so so C16 - TREE RETENTION PLAN L100-L101 LANDSCAPE PLANS L200-L202 IRRIGATION PLANS GRAPHIC SCALE C18 -WASTEWATER AND WATER UTILITY PLAN C19 - WASTEWATER AND WATER UTILITY PROFILES C13 - DETAILS C14 - DETAILS C20 - OETATLS C21 - DETAILS 30 0 10 zo so so C16 - TREE RETENTION PLAN L100-L101 LANDSCAPE PLANS L200-L202 IRRIGATION PLANS GRAPHIC SCALE SCALE:1'-30' LEGAL DESCWPON-- GENERAL SURVEY NOTESr AN UNDIVIDED ON -HALF INTEREST IN THE FOLLOWINC OESCR18ED PROPERTY: 1. THE INFORMATION DEPICTED ON THIS MAP REPRESENTS THE RESULTS OF A PORTION OF THE NORTHEAST QUARTER OF THE SOUTHWEST QUARTER OF SECTION SURVEY MADE ON THE DATE INDICATED AND CAN ONLY BE CONSIDERED AS 20, TOWNSHIP 23 NORTH, RANCE 5 EAST, W.M., IN KINC COUNTY, WASHINGTON, INOICATINC THE GENERAL CONDITION EXISTINC AT THAT TIME. DESCRIBED AS FOLLOWS: 8ECINNINC ON THE EAST LINE OF SAID SUBOMSION AT A POINT WHICH IS SOUTH 2. UNDERCROUNO UTILITIES WERE LOCATED BASED ON THE SURFACE EVIDENCE 00'08'49" WEST 475.79 FEET FROM THE NORTHEAST CORNER THEREOF; OF UTILITIES (I.E. PAINT MARKS, SAW CUTS IN PAVEMENT, COVERS, LIDS ETC.) THENCE NORTH 00'08'49" EAST 158.00 FEET; THE CONTRACTOR SHALL VERIFY THE EXACT LOCATION, ELEVATION AND SIZE OF THENCE WEST PARALLEL WITH THE NORTH LINE OF SAID SU8OMSION 654.50 FEET; EXISTING UTILITIES PRIOR TO CONSTRUCTION. THENCE SOUTH 26'18'57" EAST TO THE INTERSECTION WITH A LINE EXTENDING WESTERLY THROUGH THE SAID POINT OF 8ECINNINC AND PARALLEL WITH THE 3. TREE SIZES WERE LOCATED &SPECIES DETERMINED TO THE BEST OF OUR NORTH LINE OF SAID SUBDIVISION; ABILITY. HOWEVER, TYEE SURVEYORS DOES NOT WARRANT THE ACCURACY OF SIZE THENCE EAST ALONG SAID EXTENDED LINE TO THE POINT BEGINNING; & SPECIES SHOWN HEREON. ANY TREES CONSIDERED TO BE CRITICAL SHOULD PA EXCEPTION THEREFROM A STRIP OF LAND 30 FEET WIDE, PARALLEL WITH AND 8E VERIFIED BY A TRAINED AR80RIST. ADJOININC THE WESTERLY LINE OF SAID TRACT, FOR ROAD PURPOSES; SITUATE IN THE COUNTY OF KINC, STATE OF WASHINGTON. 4. THIS MAP GOES NOT PURPORT' TO SHOW EASEMENTS OF RECORD, IF ANY. TAX PARCEL # 2023059052 5. NO PROPERTY CORNERS WERE SET IN CONJUNCTION WITH THIS SURVEY. MEPoDIAN- ASSUMED ALL EXISTING AND PROPOSED IMPROVEMENTS SHALL BE LOCATED AND DATUM DIMENSIONED TO CITY OF RENTON SURVEY MONUMENTS, MONUMENT LINES OR STREET CENTERUNES. DIMENSIONS MUST BE DONE BY STATIONINC AND OFFSET NAVD 88 FROM THESE CONTROL LINES. BENCHMARKS NPDES PERMINi: WAR # (PENDING 30 DAY COMMENT PERI00) ORICINAL 8M: FOUND BRASS DISK IN CONCRETE IN THE INTERSECTION OF S 18TH ST AND GRANO AVE S. WCS POINT OESIGNATION : RENT787. NORTHINC = 172,295.95 EASTING = 1,302,573.67 ELEV. = 317.57 R-391001 LWEST OF TOP BACK CURB ON WEST TBM - A SETMACO IOEWAG RANT AVE S APPROVED FOR CONSTRUCTION ELEV. = 309.81 SUBJECT TO ERRORS AND OMISSIONS TBM - 8: SET HUB + MAC NAIL 20' +/- E OF SE CORNER OF HOUSE. ELEV. = 31 B.93 BY: DATE: C.O.R. 8M: MONUMENT IN CASE IN THE INTERSECTION OF EACLE RIDGE DRIVE SOUTH AND SOUTH 18TH STREET. RENTON MONUMENT IO #1063 BY; DATE: NORTHINC = 172,968.69 EASTINC = 1,301,533.10 BY. DATE: ELEV. = 261.21 BY: DATE: 1E1/4� SWI/4� SEC. 20, T. 23 14, R 5 E, WM Pacificj u=:.r1rj� ti T. «:�, � 1._,�. �� :�. a� ,� CITY OF J{ �' Design, , - 1, ✓ ONA LTE E2 SECOND ROUND CITY REVIEW COMMENTS JF 4 JH "" E. ( RENTON J'I j1,,1� r 1 FIRST ROUND CITY REVIEW COMMENTS AL 2 1 JH a®m al =�� DATUM Plannin 80din Public Works Dept. 1-� Civil Engineering .'.-/17 . 4 /17 J. !TOPPER 9/ 9/ P 1 ' - Planning Casnsu7:vr,"z N0. REVISION BYDATE APPR• r .orc iemio�ar GRANT PLACE TOWNHOMES COVER U) W 0 Z 0 F- W U J F- z ¢ cc 0 CS #14 ALL ONSITE WALKWAYS To BE POROUS "` ;- EAFiI'FIW S CALCS p (HIGH FLOW BYPASS) PAVEMENT, TOTAL 9,D31 SF. 'SEE SHEET CUTE 2, 00 CU YD r NOTES o ca-11 14LF 12' LCPE / C14 FOR DETAIL (TYP.) PUBLIC WATER EASEMENT FILL- 21200 CU YD p� FOR NEW STDRM DRAIN RIMS AND INVERTS -- STORMFILTER MANHOLE / (FROM R.O.W. LINE TO PU CB #13 NEf: 1D0 CU,-YD [CUT] 07 SEE PRDFILE AND STRUCTURE TABLE DN i _ SFMH#1W/CSF CARTRIDGES' CS 1D4LF 12" LCPE 1DEILF 12" LCPE BVlm340 s - c6 #5 87LF 72` LCPE 44LF 12" LCPE- SHEET CD9 CB#8 -- a ____ ___ _ - -- O 82LF�12' LCPE _ -- -- - - -- • FDR EXISTING STORM DRAINAGE SYSTEM SDLF 2�' LCPE _ ALDNG GRANT AVENUE AND DTHER OFFSITE BW=304312- 8W 3t BW-320 'CB#12 s 354 - - - _ , -a W STDRM DRAINAGE SYSTEM SEE SHEET CD2 ` � n ;- _ \ rL, - • FOR STANDARD STORM DRAIN MATERIALS s I AND DETAILS SEE CITY DF RENTON " - - w..: STANDARD DETAIL PLANS. \ - -:: : :: ::: : ..v' ... ..:: x 4 HEIGHT .. :... :. ..... u II ALL WALLS EXCEEDINGFEET IN HEI 11 T FF 115 n WILL REQUIRE SEPARATE BUILDING PERMITS. = W 359 • DETENTION VAULTS WILL REQUIRE SEPARATE INGRESS/EGRESS AND LITY '. 2 12.`: LCPE 1ST Fes- 1'sr FF 11ST FF= S T FF- (n EASEMENT TO BE OBTAINS ,r " " •• 348 d I D FF I 351E 1 0 ( 354.5 W BUILDING PERMIT. FROM PSE _ I` 1ST FF= r. ND FF- 2ND FF 2ND FF= 2ND FF- 2ND FF- L • ALL STORM DRAINS IN ALLEY TO BE PUBLIC. , 1ST FF= 1ST FF= 1ST FF= 1ST FF= 1ST FF= 1ST FF= 1ST FF- 1ST FF= IST FF= IST FF= 1ST FF- 1ST FF= 335.D * 358.5' 36D.0 361.5 363.0 364.5 I BW� 34LF 12 LGPE "' 376.0 . 1317.5 I 317.5 1317.5 I 3'9.D 324.D i 325.5 I 325.5 I 327.D 332D 1 333.5 333.5 2ND FF= r. 5LF 12' CPE SEE SHEET CD3 FOR CITY EASEMENT DN BW 309 '. I I I 345.D I CB #18 O TRACT A FOR VAULT MAINTENANCE, SIGNS 1DWIDE TYPE Cl \ % ' sw C� #15 I I I I I I I 9 ew-35e AND ONE WAY ARRDWS ON PAVEMENT DRIVEWAY PER RENTON U- T z ALDNG PUBLIC ALLEY. STD PLAN 1D4 \ _ 'N �� a �` f Lr ew=352 0 B #7 C 0 ROW CONTROL BMPS USED: \ � ;: _ EXISTING ONSITE PERVIOUS CONCRETE SIDEWALK=9,D31 SF. xp s T I 1ST FF= 11 ST FF=I 1ST FF I. BW-352 W 15FF- 348 5 350.D 351.5 353 U 354.E I ,.i GRASSCRETE VAULT ACCESS DRIVEWAY=1,973 SF. - 2ND FF-'I2ND FF � 2ND FF- 12ND FF� 2ND FF= I () 121 12' LC E (PRVATE) 1D3LF 1g� LCPEI(PRNAjE) I 1 1ST FF- 358.5- 36D.D TREE PRESERVATION (TRACT C) = 2,595 SF. VAULT ED PUBLIC D NTION/WE7 I 1 1' Q VAULT .�1. \ 31 LF 12' PE (PRIVAT(� 1ST FF- 1ST FF 1ST FF- 1ST FF= 1ST: FF= S3 . - 115T:FF=1 D FF : I I 3d 5 1363.0 I 36 .5 .. J 0• X 1STFF= I7 ST FF-I 15T'FF= 115T FF=1 isT FF- - ( - I -) � CONSERVATION FLOW CONTROL 8' DEEP LIVE GE j1 FF 316.D 376.D 316.D 317.5 322.0 323.5 1323.5 325.0 33D.5 332.D 332.D 2ND FF= 343.5 ' 2B,8DOCF TOT PROVIDED 6� Ln FACILITY F- 28,767CF R IZED A l z�fl „- gWa3pg. , - C WOOD 00 z 4' DEEP D STORAGE \ 1�/ _ : _ FEN.E::AL p Q PUBLIC CDMBINED DETENTION/WET VAULT. l3,6DDCF OTAL PROVIDED _ .: _ N' 7,26DC EQUIRED ,'\ .. W.. ..r m TRACT C LINE :SEEPS O _ r tax-34t �" - -- - - --JOE7AIL C13 U ENHANCED BASIC WO FACILITY Ex. EEr ucHr To \ \ - = s ss ss s -sr - s -Lb - - -- I 1 too;- AJ . TREATMENT TRAIN OF PUBLIC COMBINED - 66 YD- DETENTION/WET VAULT AND STORMFILTER D' WIDE TYPE C18 \ "� CB #2 --.. .--__-- BW-338 8N-338 MANHOLE W/CST CARTRIDGES. DRVEWAY PER RENTON \�� TD+t 10 WIDE TYPE C1 CB #3 ___- CB 7D8LF 12' LCPE. 23LF 6' LCRE : --I S1D PLAN 704.4, 99LF 12' LCPE I ,:' DRIVEWAY PER RENTON 1 IALONG SOOUfH. PROPERTY 9DLF 12' LCPE SIDEWALK AT DRIVEWAY �..�_. , m STD PLAN 7D4 R.O.W. LINE CROSSING SHOULD NOT '' LINE, SEE SHEET C13 00 OFFSITE FRONTAGE LOCATIONS DEPRESSED AT / v `a 4. ' v ' TOTAL ONSITE AREA 1 =2 . 11 AC.A UPSTREAM FOR LTRIBU 60LF 12" LCPE O LOCATIONS WHERE ce 3SD \ q CB #112' LCPE I- AREA = 0 . 0 6 AC . LANDSCAPING IS MDRE Ex�snr/c cuRe ° TRIBUTARY THAN s FEET WIDE TOTALIMPERVIOUS AREA �l�_21 C .�, 3D ° '° 2D 3D 6D w IMPEVIOUS AREA = 0.03 AC. z v ' v' (AFTER APPLY FLOW CONTROL BMP CREDITS) AREA=0.22 AC.GFIA�HICSCALE TILL GRASS = 0. 03 AC. SC E:1'-W' 6D' PUBLIC R.O.W. \ - \s r- TILL GRASS = 1.06 AC., TILL PASTURE = 0.06 AC. (TILL GRASS) R.O.W. 31.5' PUBLIC 1/2 R.O.W. 2D.5' PUBLIC R.O.W. 2.5' 21' PUBLIC R.O.W. 2.5' 2D.5' PUBLIC R.O.W. 2D.5' PUBLIC R.O.W. 3' 3D' 35' SIDEWALK D' 3 3 3 3 ') o I o --__ 2D' TRAVELLED WAY �� o I o B - 1.5' R.D.W. DEDICATIDN i� 5' PRIVATE SIDEWALK 5' PRIVATE SIDEWALK I LAND- 35.87't TRAVELLED WAY (VARIES) B' I � 2D' TRAVELLED WAY I 2D' TRAVELLED WAY 1 � EXISSIDE AL LANDSCAPE F N F N ' SIDEWALK EXISTING 16.D 4" THICK CONCRETE 4" THICK CDNCRETE I =4" THICK CONCRETE SOAPING' 2D TRAVELLED WAY CURB (TYPICAL) 6" 41DEWALK o o I o EXISTING 1D I. 1D [ SIDEWALK = 1D' 1D' = 1D' 1D' 1D' 1D' PAVEMENT 2% 1.5 i �'li 3 3 ' �SIDEWALK w = CENTER LINE OF 1 I 0 I it o ( zl �I PAVE NT D.6't CURB S) I3 B% CURB ex e% 6� B% CURB B% INSTALL WOOD � 0 o MAX. i 2% 2% 11.5 MAX Axi 2q, 2q, �MA MAX. I 2% 2q, , 1.5 MAX. FENCE ALDNG F I I 2�R6 2% 6% `\\ � PROPERTY LINE w I , �,p,X MAX EXISTING EXISTING `EXISTING of i 2" A.0 ,,poo QQQ a 0 / WEARING COURSE �) ( WEARING CDURSE a WEARING COURSE POWER STORM GAS o ( WEARING COURSE J/ 2" A.0 1D" WATER MAIN .11�-IXI 2" A.0 2" A.0 w m 2" A.0 12" STDRM SEWER 5' 1D' 7' BEARING CDURSE EXISTING EXISTING BEARING COURSE 1D" WATER MAN B' 5 5' B' BEARING CDURSE 6.7't 3.3't BEARING CDURSE CABLE WATER iD" WATER MAIN 5.4't 4.3't 6" CRUSHED ROCK 12" STDRM S R 6" CRUSHED ROCK 6" CRUSHED RDCK 6" CRUSHED ROCK NOTE; EXISTING UTILITY DEPTHS ARE ASSUMED SUBGRADE SUBGRADE SUBGRADE B" SANITARY SEWER SUBGRADE GRANT AVENUE 12" STDRM SEWER B" SANITARY SEWER 12" STORM SEWER 1D" WATER MAIN CROSS ROM PAVEMENT THICKNESS PER COR 4-6-D6D.F.5 ROM PAVEMENT THICKNESS PER COR 4-6-D6D.F.5 NOTE: PAVEMENT THICKNESS PER CDR 4-6-D6D.F.5 NOTE" PAVEMENT THICKNESS PER COR 4-6-D60.F.5 CROSS SECTION A FINAL PAVEMENT THICKNESSES PENDING FINAL PAVEMENT THICKNESSES PENDING FINAL PAVEMENT THICKNESSES PENDING FINAL PAVEMENT THICKNESSES PENDING SCALE. T-V GEOTECHNICAL ENGINEER'S REPORT GEOTECHNICAL ENGINEER'S REPORT GEOTECHNICAL ENGINEER'S REPORT GEOTECHNICAL ENGINEER'S REPORT 1D' GRANT CIRCLE S.E. (PUBLIC ALLEY) PUBLIC ALLEY GRANT CIRCLE (PUBLIC ALLEY) GRANT CIRCLE (PUBLIC ALLEY) TEMPORARY CROSS SECTION C CROSS SECTION D CROSS SECTION E CROSS SECTION F CONSTRUCTION SCALE T-V SCALE T-V SCALE T-90' SCALE T-10' EASEMENT FROM PSE .5' 2D.5' PUBLIC R.O.W. 3' 1D' z TEMPDRARY �I L2D' TRAVELLED WAY v CONSTRUCTION w EASEMENT 1n FROM PSE 22.35' w 31 oI I 1D' 1D' I, z i z 5.83' 4' VARIES z Mqk ai i' Ij�' Z 1 z 4' 15.5' 0 CURB I irl N B.D' lir 4' MAX. HIGH wI I 2% 2% Ia R-391008 NEW ROCKERY 3 0 0 0 0__- SEE SHT C14 I i I Mqk. a� 3 3 _, a APPROVED FOR CONSTRUCTION FOR DETAIL 2" A.0 W WEARING CDURSE B% B% I SUBJECT TO ERRORS AND OMISSIONS 4' 4' MAX. HIGH c 12" STORM SEWER 2 A.0 NEW RDCKERY I 1.5% MAX. MAX. 1.5q, I G 1D" WATER MAIN BEARING COURSE I 4' MAX. HIGH 5' 1D' 7' SEE SHT C14 6" CRUSHED RDCK NEW ROCKERIES BY: DATE. SUBGRADE FOR DETAIL I I SEE SHT C14 = B" SANITARY SEWER 4" CONCRETE z FINAL; PAVEMENT THICKNESS PER CON 4-6-D6D.F.5 4" CDNCRETE SIDEWALK FOR DETAIL BY: DATE: FINAL PAVEMENT THICKNESSES PENDING SIDEWALK GEOTECHNICAL ENGINEER'S REPORT GRANT CIRCLE S.E. (PUBLIC ALLEY) DATE: O CROSS SECTION G CROSS SECTION H BY: DATE: Uj CROSS SEC ON B oS�Po M yDAAF SCALE10' T-SCALE T-V SST-V Q Pacific 9 ' lJJJ o J. 11oFFFR �n .� wn,:n?.. ti CITY OF GRANT PLACE TOWNHOMES 2016-12-2 RENTON em z PJ i7 Design, �' `sf �15RE 6\�� 2 SECOND ROUND CITY REVIEW COMMENTS JF 4 JH "�` E. L �__ __ __ DATUM z Civil Engineering 1 /oNAL Ei' �-I/I� 1 FIRST ROUND CITY REVIEW COMMENTS AL 1 JH =� ,cnl a� I Planning/Building/Public Works Dept. GRADING ROADWAY AND DRAINAGE PLAN < Plaara;t➢ng onsal8�nis NO. REVISION BY DATE APPR � '0M�"tO01°M°' COB 21 (� 0 r co O d' W 07 W 2 0 2 Z 0 W U Q J D_ Z Q rr 0 C8 #1 (TYPE 1) C8 #10 (TYPE 1) STA=10+10.32, 9.0' L STA-2+52.48, 9.0' L RIM ELEV = 305.28 RIM ELEV = 319.05 I.E. 12" LCPE E = 302.28 I.E. 12" LCPE E = 316.05 I.E. 12" LCPE N = 302.28 I.E. 12" LCPE W = 316.05 C8 #2 TYPE I C8 #11 TYPE I STA=9+45.62 9.0' L STA.=3+56.02, 9.0' L RIM ELEV = 314.03 RIM ELEV = 327.00 I.E. 12" LCPE E = 311.03 I.E. 12" LCPE E = 324.00 I.E. 12" LCPE W = 311.03 I.E. 12" LCPE W = 324.00 C8 #3 (TYPE 1) C8 #12 (TYPE 1) STA=8+55.73, 9.0' L STA.=4+61.81, 9.0' L RIM ELEV = 317.63 RIM ELEV = 335.09 I.E. 12" LCPE E = 314.63 I.E. 12" LCPE W = 332.09 I.E. 12" LCPE W = 314.63 I.E. 12" LCPE E = 332.09 C8 TYPE I C8 #13 TYPE I STA=7+56.80, 9.0' L STA. 5+00.39, 9.0' L RIM ELEV = 324.90 RIM ELEV = 340.61 I.E. 10 LCPE E = 321.90 I.E. 12" LCPE S = 336.95 I.E. 10 LCPE W = 321.90 I.E. 12" LCPE W = 336.95 C8 #5 (TYPE 1) C8 #14 (TYPE 11-48.0) STA=6+48.87, 9.0' L HICH FLOW 8YPASS RIM ELEV = 333.60 STA.=0+54.07, 16.5' L I.E. 12- LCPE W - - 330.59 RIM ELEV = 296.27 I.E. 12" LCPE E = 288.50 CB #6 (TYPE 1) I.E. 12" LCPE SE = 288.50 STA: 5+47.27, 10.0' L I.E. 12" LCPE W = 288.50 RIM ELEV = 344.33 I.E. 12" LCPE E = 341.60 C8#15 (TYPE 1) W/VANED I.E. 12" LCPE N = 341.60 CRATE (LOCKINC) RIM ELEV = 315.40 C8 #7 (TYPE 1) I.E. 12" LCPE E = 312.40 STA=1+21.20, 0.0' I.E. 12" LCPE SW = 312.40 RIM ELEV = 351.60 I.E. 10 RCP E = 348.88 CB#16 (TYPE 1) W/VANED I.E. 10 LCPE W = 348.88 CRATE (LOCKINC) RIM ELEV = 322.10 C8 #8 (TYPE 1) I.E. 12" LCPE E = 319.10 STA =0+82.93, 9.0' L I.E. 12" LCPE W = 319.10 RIM ELEV = 303.50 LE 12" LCPE E = 300.50 C8#17 (TYPE 1) W/VANEO I.E. 12' LCPE S = 300.50 CRATE (LOCKINC) RIM ELEV = 329.90 CB #9 (TYPE 1) I.E. 10 LCPE E = 326.90 STA-1+65.07. 9.0' L I.E. 12" LCPE W = 326.90 RIM ELEV = 315.53 I.E. 12" LCPE E = 312.53 I.E. 12" LCPE W = 312.53 Pacific jna�q.t'IIJj 3jj .L r; 1I �� Civil Enginaerfng r Punning cansujtzanzs C8 #18 (TYPE 1) W/VANEO GRATE (LOCKING) STA-1+35.87 0.0' RIM ELEV = 355.00 I.E. 12" RCP W = 350.00 STORMMLTER MANHOLE SFMH#1 (TYPE 11 72 0) STA.=0+63.24 8.4' L RIM ELEV = 300.56 I.E. 12" LCPE SE=290.87 I.E. 12" LCPE W = 288.57 W/3-18- HICH (7.5 CPM PER CARTRIOGE) CSF CARTRIOCES EX. SOMH-1 2 TYPE ( ) W / souo uo STA-0+16.15, 48.4' L RIM ELEV = 294.54 I.E. 12- LCPE E (NEW)=287.34 I.E. 12' EX CMP N = 290.00 I.E. 12" EX CMP NE = 289.90 I.E. 12" EX CMP SE = 287.10 I.E. 15" CMP W = 286.60 _............... ... ..... <_. ............... ....... _... . _......_.... ........._...._. :.................. .._....................... 1. ....... ... ....................................__._................ .....>......... .. . .....:............. . .........:........................... :v ......_ ............................... ...........................................:......... j ......... ....... ....... ...................................... ........... .........................z............................... _...................... _..+_........ _...:.::........... _. ....................................................... ............................................ ._.. _........ .. ............. ...... ..........:. .................................... ........... ............ ::::: .... . ..... .. :I:-:...........................:......... ........ ::::: ::.:::{ V ....................................... ........................................ ...................,........ ......... ...... .......... ._aZ ................ : .':.........:... ..... ....... .............................. .....:::::::: ........................... ....... ........ .. ..... . ........ .... .... .. .. ._....._... ...':.'::'. . . . �sa..j.. ......... ..... .. ...... 62 ... ........ .:... .................................. ..... ..... ........ ...... .... .. ..................................................... ................0 1.72 .................. 0 �... .............................. w a m ... ..................... .......................................o....#............_..._.........._................................ ............................. ra. m......... T-:.. <o� .. .................'A {....25............... �✓� u 3bs 40...... .... _r, 4� t .. 2. c A ...............................:. ................................. ............................................................ ................................. ................................. ..... -: ag............................. ......... .....R ..EID ......::::...... 7.2e LCAE::i .................... :.SE:.. UBLIC REVISION 0 370 370 ::::.: 0 365 -:::................................................................................... ..... ...... .. ...... ..... ..... ..... ..... ...... ...... .... . . ;..... . � ....... ..... 365 -......................................................................... ........................ -7f7" :...... ....... i............ TYPE�1 " .... 1..........).... . ... 360 _.._................o - ........o ... a ...-..o ...o ......_......_.._......._........._........_...... .. T ... S..A, ... ....... ...._ 1+ . O .....21..E ....P.•�'... ........................ .../ 360 - - µ Y M O M O r7... .. R1M- L:EV--351-.60.... - . ... ... /.. / .. . 355-....................u..��.....yi. _........ T tt.....R > .ii.............__.................. > .......tF.. "12".:"t. � .:W:-:"3988>�:"..: .._....._ ..:'":':. ...... 355 4 G ... ..... ... ..:........... �5350 ... .......................................��...............;....... .................................. ... 7. ... 350 .._. 1. ....... . 0 345: ...... ................. .. .. nR� 345 _ ..... ........... ...'. a _.�-. ....... 5 _ ..................... 340_.......-',.,_i ..-. _<.._.._...._................................ �....-. ... ,ram ......_ .. ............ .......S=.O.D76Z... 340 r ..::..................�. L . o 335 t............ LOCK -(LOCK _..... 335 _.............:........................__.....................STA: 1}35:87;...Or............. ..........&00............. .............i.........................................................LE .............€.................................................RIM-ELEV= .00............. 5 330-:.:.:.:.:.:.:.:.:.:.:..:...::.:.:.:..:.....:::'g.: :......Pe.'�::.::.:..:.:.:.:.:.aF:.:.. ..:.:RCe.:_Ml:.:=..:.:35.:oa:_:::.::.::.:.:.:' 330 -.............:...................S........)..............................:.............................. YAW Y:CRATE (LOCKiN :):::::::::::::::::::................... _ ....... 0 325_:.:.....................:....................... _.............:........... ......... TA. O+ ...... .................................................................:......................................... IM..EIEV O= U. �..344. '...................:.. 3.................................................... ..... 325 15 3200- ........................I E-12°- PEN . ..341:60 .......................................... 320 - 25 0+00 PUBLIC ALLEY PR6FI1LE1+00 1+50 10 H. SCALE: T-30' V. SCALE: 1'a10' .......i.................................. .......i...... .......{...... J ...... ............................. ....... ... ............ ..........: ............._.......... ......._....._... 290 YPE. p................................... 285 105:26.....- ... ... ....... ::::........ Io2.2g.................................. 280 .......:.................................... 270 10 00 10 60 rRom T. cx�r1 J. HOPPER W COMMENTS JF 4 °Y" I- NARSIINCOMMENTS AL '). 2 1�JH ucuu�BY . HOPPER GATE R �^*a*A "tl1 DATUM a nu oac r iar ac xo� �onc waoia'wr CITY OF RENTON Planning/80ding/Public Works Oept. R-391009 APPROVED FOR CONSTRUCTION SUBJECT TO ERRORS AND OMISSIONS BY: DATE: . BY: DATE: . BY: DATE: . BY: DATE: . GRANT PLACE TOWNHOMES ROAD AND STORM PROFILES 2016-1 LO 00 00 O O O LO T Q J W) Q� G.7 W 5 U) W 2 0 2 Z> 0 1-- W U Q J z Q 0 Part C Performance Standards The site is located in Duration Flow Control Area (Forest existing condition). Since no problem has been identified within the site and its downstream area, level 2 flow control (forest existing condition) is required. Since the project is a multi -family development, Enhanced basic water quality treatment is required. Per SWDM section 1.2.3.3 and 5.2, Flow Control BMPs are required for the onsite development. Since this project is a PUD with individual lots, applying Flow control BMP's for more than 10% of each lot area is required. The feasibility and applicability of full dispersion is studied first, the study found full dispersion is not suitable for this site to fully disperse the new impervious areas and new non-native pervious areas because long native flow path is not available due to the high impervious area ratio. Full infiltration is also not suitable for this site because onsite soil is till soil (Alderwood gravelly sandy loam, 6 to 15% slopes, AgC and 15% to 25% slopes, AgD) according to City of Renton Soils Map. The following flow control BMPs are used: 1. Native growth retention area (TRACT C, 2,595 square feet, counted as pasture area). Impervious area credit allowed by this BMP is 2,595/3.5 = 741 square feet per section C 2.10 of Appendix C of 2009 KCSWDM. 2. Pervious concrete walkway (4" pervious concrete on 2" choker course on 4" aggregate base, with 2 to 5% slope) for all onsite sidewalks (8,976 square feet, credited as 50% impervious area, 50% grass). 3. Grasscrete pavement (4" grasscrete, on 2" choker course on 6" crushed stone base) for vault maintenance access driveway (1972 square feet, credited as 50% impervious area, 50% grass) 4. Perforated tie lines for downspout connections. (no credit) Total impervious area treated by flow control BMPs is 11,689 square feet which is approximately 32.8% (> 10% of the total lot areas of the 36 zero lot line lots (total 35,630 square feet which is 3,563 square feet). Final signed Flow Control BMP Covenant is required prior permit is issued and will be recorded with the PUD Plat map. Onsite flow control facility is provided by a combined detention/wet vault to provide the required. For onsite improvement, the proposed project will use 10 feet minimum perforated downspout connection for each building, use a combined detention/wet vault to provide the required Duration standard forested site conditions flow control at the point of convergence (at SDMH#1 at Grant Avenue South) and use a treatment train of wet vault and StormFilter manhole with CSF cartridges to provide the required Enhanced Basic water quality treatment. Treated runoff will be discharged to its natural discharged location (SDMH#1 at Grant Avenue South). See Section 2 of this report regarding special requirements, the only special requirement applicable to this site is special requirement 1.3.4 for source control. Dumpsters and recycle bins will be stored in the garages of each units. Since the site is not a high use site, oil control is not required. 27 The new onsite conveyance system (the pipes are minimum 12-inch diameter LCPE pipes with minimum slopes of 0.5%) is designed per chapter 4 of the City of Renton Amendments to the 2009 KCSWDM to convey the 25-year peak with 6 inches of free board and the 100-year peak flows. For offsite frontage improvement, as discussed in Section 1 of this report, no flow control or water quality treatment is required 28 Part D Flow Control System Flow control facility: A combined detention/wet vault is used to provide the required Level 2 flow control (forest existing condition) at the point of convergence. The offsite frontage improvement is counted as bypassed areas. KCRTS method is used to size the detention system. Retention/Detention Facility Type of Facility: Facility Length: Facility Width: Facility Area: Effective Storage Depth: Stage 0 Elevation: Storage Volume: Riser Head: Riser Diameter: Number of orifices: Detention Vault 90.00 ft 40.00 ft 3600. sq. ft 7.95 ft 0.00 ft 28620. cu. ft 7.95 ft 12.00 inches 3 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 0.00 0.68 0.035 2 4.65 1.25 0.078 4.0 3 7.20 1.00 0.024 4.0 Top Notch Weir: None Outflow Rating Curve: None Stage Elevation Storage Discharge Percolation (ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs) 0.00 0.00 0. 0.000 0.000 0.00 0.01 0.01 36. 0.001 0.001 0.00 0.02 0.02 72. 0.002 0.002 0.00 0.03 0.03 108. 0.002 0.002 0.00 0.04 0.04 144. 0.003 0.003 0.00 0.05 0.05 180. 0.004 0.003 0.00 0.06 0.06 216. 0.005 0.003 0.00 0.21 0.21 756. 0.017 0.006 0.00 0.37 0.37 1332. 0.031 0.008 0.00 0.52 0.52 1872. 0.043 0.009 0.00 0.68 0.68 2448. 0.056 0.010 0.00 0.84 0.84 3024. 0.069 0.011 0.00 0.99 0.99 3564. 0.082 0.012 0.00 1.15 1.15 4140. 0.095 0.013 0.00 1.30 1.30 4680. 0.107 0.014 0.00 1.46 1.46 5256. 0.121 0.015 0.00 1.62 1.62 5832. 0.134 0.016 0.00 1.77 1.77 6372. 0.146 0.017 0.00 1.93 1.93 6948. 0.160 0.017 0.00 2.08 2.08 7488. 0.172 0.018 0.00 2.24 2.24 8064. 0.185 0.019 0.00 2.39 2.39 8604. 0.198 0.019 0.00 2.55 2.55 9180. 0.211 0.020 0.00 2.71 2.71 9756. 0.224 0.021 0.00 2.86 2.86 10296. 0.236 0.021 0.00 3.02 3.02 10872. 0.250 0.022 0.00 3.17 3.17 11412. 0.262 0.022 0.00 3.33 3.33 11988. 0.275 0.023 0.00 3.49 3.49 12564. 0.288 0.023 0.00 3.64 3.64 13104. 0.301 0.024 0.00 3.80 3.80 13680. 0.314 0.024 0.00 Me 3.95 3.95 14220. 0.326 0.025 0.00 4.11 4.11 14796. 0.340 0.025 0.00 4.27 4.27 15372. 0.353 0.026 0.00 4.42 4.42 15912. 0.365 0.026 0.00 4.58 4.58 16488. 0.379 0.027 0.00 4.65 4.65 16740. 0.384 0.027 0.00 4.66 4.66 16776. 0.385 0.027 0.00 4.68 4.68 16848. 0.387 0.028 0.00 4.69 4.69 16884. 0.388 0.030 0.00 4.70 4.70 16920. 0.388 0.032 0.00 4.72 4.72 16992. 0.390 0.035 0.00 4.73 4.73 17028. 0.391 0.039 0.00 4.74 4.74 17064. 0.392 0.040 0.00 4.75 4.75 17100. 0.393 0.041 0.00 4.91 4.91 17676. 0.406 0.049 0.00 5.07 5.07 18252. 0.419 0.056 0.00 5.22 5.22 18792. 0.431 0.061 0.00 5.38 5.38 19368. 0.445 0.065 0.00 5.53 5.53 19908. 0.457 0.069 0.00 5.69 5.69 20484. 0.470 0.073 0.00 5.85 5.85 21060. 0.483 0.077 0.00 6.00 6.00 21600. 0.496 0.080 0.00 6.16 6.16 22176. 0.509 0.083 0.00 6.31 6.31 22716. 0.521 0.086 0.00 6.47 6.47 23292. 0.535 0.089 0.00 6.62 6.62 23832. 0.547 0.092 0.00 6.78 6.78 24408. 0.560 0.095 0.00 6.94 6.94 24984. 0.574 0.097 0.00 7.09 7.09 25524. 0.586 0.100 0.00 7.20 7.20 25920. 0.595 0.101 0.00 7.21 7.21 25956. 0.596 0.102 0.00 7.22 7.22 25992. 0.597 0.102 0.00 7.23 7.23 26028. 0.598 0.104 0.00 7.24 7.24 26064. 0.598 0.105 0.00 7.25 7.25 26100. 0.599 0.107 0.00 7.26 7.26 26136. 0.600 0.109 0.00 7.27 7.27 26172. 0.601 0.110 0.00 7.28 7.28 26208. 0.602 0.110 0.00 7.29 7.29 26244. 0.602 0.111 0.00 7.45 7.45 26820. 0.616 0.119 0.00 7.61 7.61 27396. 0.629 0.125 0.00 7.76 7.76 27936. 0.641 0.130 0.00 7.92 7.92 28512. 0.655 0.135 0.00 7.95 7.95 28620. 0.657 0.136 0.00 8.05 8.05 28980. 0.665 0.447 0.00 8.15 8.15 29340. 0.674 1.010 0.00 8.25 8.25 29700. 0.682 1.740 0.00 8.35 8.35 30060. 0.690 2.540 0.00 8.45 8.45 30420. 0.698 2.820 0.00 8.55 8.55 30780. 0.707 3.080 0.00 8.65 8.65 31140. 0.715 3.320 0.00 8.75 8.75 31500. 0.723 3.540 0.00 8.85 8.85 31860. 0.731 3.750 0.00 8.95 8.95 32220. 0.740 3.940 0.00 9.05 9.05 32580. 0.748 4.130 0.00 9.15 9.15 32940. 0.756 4.310 0.00 9.25 9.25 33300. 0.764 4.480 0.00 9.35 9.35 33660. 0.773 4.640 0.00 9.45 9.45 34020. 0.781 4.800 0.00 9.55 9.55 34380. 0.789 4.960 0.00 9.65 9.65 34740. 0.798 5.110 0.00 9.75 9.75 35100. 0.806 5.250 0.00 Hyd Inflow Outflow Peak Storage Stage Elev (Cu-Ft) (Ac-Ft) im 1 0.81 0.26 7.99 7.99 28761. 0.660 2 0.40 0.13 7.66 7.66 27581. 0.633 3 0.48 0.09 6.58 6.58 23696. 0.544 4 0.52 0.09 6.51 6.51 23428. 0.538 5 0.42 0.06 5.29 5.29 19055. 0.437 6 0.43 0.04 4.76 4.76 17147. 0.394 7 0.33 0.03 4.67 4.67 16824. 0.386 8 0.36 0.02 2.99 2.99 10776. 0.247 Hyd R/D Facility Tributary Reservoir POC Outflow Outflow Inflow Inflow Target Calc 1 0.26 0.02 ******** 0.17 0.26 2 0.13 0.01 ******** ******* 0.13 3 0.09 0.01 ******** 0.10 0.09 4 0.09 0.01 ******** ******* 0.09 5 0.06 0.01 ******** ******* 0.07 6 0.04 0.01 ******** 0.06 0.04 7 0.03 0.01 ******** ******* 0.03 8 0.02 0.01 ******** ******* 0.03 ---------------------------------- Route Time Series through Facility Inflow Time Series File:dev.tsf Outflow Time Series File:rdout POC Time Series File:ddout Inflow/Outflow Analysis Peak Inflow Discharge: 0.806 CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge: 0.258 CFS at 11:00 on Jan 9 in Year 8 Peak Reservoir Stage: 7.99 Ft Peak Reservoir Elev: 7.99 Ft Peak Reservoir Storage: 28761. Cu-Ft 0.660 Ac-Ft Add Time Series:offsite.tsf Peak Summed Discharge: 0.263 CFS at 11:00 on Jan 9 in Year 8 Point of Compliance File:dsout.tsf Flow Frequency Analysis Time Series File:rdout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.127 2 2/09/01 20:00 0.028 7 1/07/02 4:00 0.091 3 3/06/03 22:00 0.022 8 8/26/04 8:00 0.042 6 1/08/05 3:00 0.063 5 1/19/06 0:00 0.090 4 11/24/06 8:00 0.258 1 1/09/08 11:00 Computed Peaks Flow Frequency Analysis Time Series File:dsout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.130 2 2/09/01 20:00 0.031 7 1/05/02 16:00 0.094 3 3/06/03 21:00 0.027 8 8/26/04 2:00 0.043 6 1/08/05 2:00 -----Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) (ft) Period 0.258 7.99 1 100.00 0.990 0.127 7.66 2 25.00 0.960 0.091 6.58 3 10.00 0.900 0.090 6.51 4 5.00 0.800 0.063 5.29 5 3.00 0.667 0.042 4.76 6 2.00 0.500 0.028 4.67 7 1.30 0.231 0.022 2.99 8 1.10 0.091 0.214 7.98 50.00 0.980 -----Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) Period 0.263 1 100.00 0.990 0.130 2 25.00 0.960 0.094 3 10.00 0.900 0.093 4 5.00 0.800 0.065 5 3.00 0.667 31 0.065 5 1/18/06 23:00 0.043 6 2.00 0.500 0.093 4 11/24/06 7:00 0.031 7 1.30 0.231 0.263 1 1/09/08 11:00 0.027 8 1.10 0.091 Computed Peaks 0.218 50.00 0.980 Flow Duration from Time Series File:rdout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS o % % 0.002 28152 45.910 45.910 54.090 0.541E+00 0.005 7792 12.707 58.617 41.383 0.414E+00 0.009 6633 10.817 69.434 30.566 0.306E+00 0.013 6874 11.210 80.644 19.356 0.194E+00 0.016 4170 6.800 87.445 12.555 0.126E+00 0.020 3501 5.709 93.154 6.846 0.685E-01 0.023 2006 3.271 96.425 3.575 0.357E-01 0.027 1574 2.567 98.992 1.008 0.101E-01 0.030 198 0.323 99.315 0.685 0.685E-02 0.034 16 0.026 99.341 0.659 0.659E-02 0.037 8 0.013 99.354 0.646 0.646E-02 0.041 19 0.031 99.385 0.615 0.615E-02 0.044 42 0.068 99.454 0.546 0.546E-02 0.048 32 0.052 99.506 0.494 0.494E-02 0.051 39 0.064 99.569 0.431 0.431E-02 0.055 31 0.051 99.620 0.380 0.380E-02 0.059 33 0.054 99.674 0.326 0.326E-02 0.062 25 0.041 99.715 0.285 0.285E-02 0.066 30 0.049 99.764 0.236 0.236E-02 0.069 17 0.028 99.791 0.209 0.209E-02 0.073 16 0.026 99.817 0.183 0.183E-02 0.076 11 0.018 99.835 0.165 0.165E-02 0.080 14 0.023 99.858 0.142 0.142E-02 0.083 16 0.026 99.884 0.116 0.116E-02 0.087 15 0.024 99.909 0.091 0.913E-03 0.090 16 0.026 99.935 0.065 0.652E-03 0.094 10 0.016 99.951 0.049 0.489E-03 0.097 12 0.020 99.971 0.029 0.294E-03 0.101 5 0.008 99.979 0.021 0.212E-03 0.104 1 0.002 99.980 0.020 0.196E-03 0.108 1 0.002 99.982 0.018 0.179E-03 0.112 1 0.002 99.984 0.016 0.163E-03 0.115 2 0.003 99.987 0.013 0.130E-03 0.119 1 0.002 99.989 0.011 0.114E-03 0.122 2 0.003 99.992 0.008 0.815E-04 0.126 3 0.005 99.997 0.003 0.326E-04 Flow Duration from Time Series File:dsout.tsf Cutoff Count Frequency CDF Exceedence_Probability CFS o % % 0.002 28141 45.892 45.892 54.108 0.541E+00 0.005 7745 12.630 58.523 41.477 0.415E+00 0.009 6603 10.768 69.291 30.709 0.307E+00 0.013 6777 11.052 80.342 19.658 0.197E+00 0.016 4416 7.202 87.544 12.456 0.125E+00 0.020 3369 5.494 93.038 6.962 0.696E-01 0.024 1945 3.172 96.210 3.790 0.379E-01 0.027 1641 2.676 98.886 1.114 0.111E-01 0.031 244 0.398 99.284 0.716 0.716E-02 0.035 34 0.055 99.340 0.660 0.660E-02 0.038 9 0.015 99.354 0.646 0.646E-02 0.042 21 0.034 99.388 0.612 0.612E-02 0.046 43 0.070 99.459 0.541 0.541E-02 0.049 33 0.054 99.512 0.488 0.488E-02 0.053 37 0.060 99.573 0.427 0.427E-02 0.056 28 0.046 99.618 0.382 0.382E-02 0.060 34 0.055 99.674 0.326 0.326E-02 32 0.064 24 0.039 99.713 0.287 0.287E-02 0.067 29 0.047 99.760 0.240 0.240E-02 0.071 20 0.033 99.793 0.207 0.207E-02 0.075 15 0.024 99.817 0.183 0.183E-02 0.078 10 0.016 99.834 0.166 0.166E-02 0.082 15 0.024 99.858 0.142 0.142E-02 0.086 17 0.028 99.886 0.114 0.114E-02 0.089 11 0.018 99.904 0.096 0.962E-03 0.093 19 0.031 99.935 0.065 0.652E-03 0.096 9 0.015 99.949 0.051 0.506E-03 0.100 13 0.021 99.971 0.029 0.294E-03 0.104 4 0.007 99.977 0.023 0.228E-03 0.107 2 0.003 99.980 0.020 0.196E-03 0.111 1 0.002 99.982 0.018 0.179E-03 0.115 1 0.002 99.984 0.016 0.163E-03 0.118 1 0.002 99.985 0.015 0.147E-03 0.122 2 0.003 99.989 0.011 0.114E-03 0.126 2 0.003 99.992 0.008 0.815E-04 0.129 3 0.005 99.997 0.003 0.326E-04 Duration Comparison Anaylsis Base File: pre.tsf New File: dsout.tsf Cutoff Units: Discharge in CFS -----Fraction of Time ----- ---------Check of Tolerance------- CutoffBase New %Change Probability Base New %Change 0.030 0.95E-02 0.75E-02 -21.4 I 0.95E-02 0.030 0.028 -6.9 0.038 I 0.64E-02 0.65E-02 1.5 I 0.64E-02 0.038 0.040 4.7 0.046 I 0.50E-02 0.53E-02 7.6 0.50E-02 0.046 0.049 5.6 0.055 0.37E-02 0.40E-02 8.8 I 0.37E-02 0.055 0.057 5.2 0.063 0.29E-02 0.30E-02 4.0 0.29E-02 0.063 0.064 1.8 0.071 0.22E-02 0.21E-02 -6.6 0.22E-02 0.071 0.069 -2.7 0.079 0.15E-02 0.16E-02 5.5 0.15E-02 0.079 0.080 1.3 0.087 0.10E-02 0.10E-02 1.6 I 0.10E-02 0.087 0.088 0.3 0.096 I 0.62E-03 0.52E-03 -15.8 I 0.62E-03 0.096 0.094 -1.9 0.104 0.34E-03 0.23E-03 -33.3 I 0.34E-03 0.104 0.099 -4.6 0.112 ( 0.21E-03 0.18E-03 -15.4 I 0.21E-03 0.112 0.107 -4.6 0.120 0.16E-03 0.11E-03 -30.0 I 0.16E-03 0.120 0.116 -3.6 0.129 0.11E-03 0.49E-04 -57.1 I 0.11E-03 0.129 0.123 -4.6 0.137 0.16E-04 0.00E+00 -100.0 0.16E-04 0.137 0.130 -4.9 Maximum positive excursion = 0.003 cfs ( 7.4%) occurring at 0.038 cfs on the Base Data:pre.tsf and at 0.041 cfs on the New Data:dsout.tsf Maximum negative excursion = 0.004 cfs (-12.8%) occurring at 0.034 cfs on the Base Data:pre.tsf and at 0.030 cfs on the New Data:dsout.tsf 33 d-9 d., o 10 1 lo, 10 -1 10 1 10 -1 10, Probability Exceedence Predeveloped duration VS developed duration at point of convergence Retum Period I I Io inn C.m.I.M. Probability Predeveloped peaks VS developed peaks at point of convergence 34 The hydrograph of the onsite detained runoff (detention vault release, include the 0.22 acre upstream tributary area, rdout.tsf) will be added with the hydrograph of the offsite bypass area (Grant Avenue South frontage improvement, offsite.tsf). The combined hydrograph (dsout.tsf) is used to compare with the existing hydrograph of the total combined site (including onsite area 2.11 acres, upstream tributary area 0.22 acres and Grant Avenue South frontage improvement area 0.06 acres, total 2.39 acres, pre.tsf) at the point of compliance at existing storm manhole SDMH#1 at Grant Avenue South to meet the requirements of Level 2 detention. Peak combined detention/wet vault release rate (rdout.tsf): Q2y = 0.042 cfs Q10y = 0.091 cfs Q100y = 0.258 cfs Peak developed peak flows at point of compliance (dsout.tsf): Due to the peak shift effect of the detention vault the dsout.tsf peaks are less than the sum of the rdout.tsf peaks plus the offsite.tsf peaks. Hydrograph dsout,tsf = hydrograph rdout.tsf + hydrograph offsite.tsf Peaks dsout.tsf < peaks rdout.tsf + peaks offsite.tsf Q2y = 0.043 cfs < 0.071 cfs (existing site condition, pre.tsf), o.k. Q10y = 0.094 cfs < 0.124 cfs (existing site condition, pre.tsf), o.k. Q100y = 0.263 cfs. The proposed combined detention/wet vault (90' L x 40' W x 8' H live storage) provides 28,800 cubic feet of live storage. Required live storage is 28,761 cubic feet for the 100 year peak flow, o.k. Two flow control devices are used inside the vault. One is an 8" tee with shear gate, a 0.68" bottom orifice, a solid top and an 8" outfall pipe to the StormFilter manhole which controls the under 2-year flow to the StormFilter manhole, the other is a 12" riser for over 2-year flow control. The 12" riser has a 1.25" bottom orifice (used as the 2nd orifice) and a V orifice at a 4" elbow (used as the 3rd orifice), the top of the riser is used for overflow for over 100 year storm event. The 12" outfall pipe for the 12" flow control riser is connected to a type 2 catch basin bypassing the StormFilter manhole. The vault also has an 8" outfall with shear gate for maintenance dewatering. Use KCRTS method with 15 minute time step to calculate 100 year peak overflow for the detention system. 92 40 Land Use Summary -,area ____.—_� Till Forest! 0.00 acres i Till Pasturei 0.00 acres' Till Grassi 0.73 acres! Outwash Forest 0.00 acres 1 Outwash Pasture 0.00 acres Outwash Grass` 0.00 acres! Wetland 0.00 acres Impervious) 1.30 acres; -Total---I Y� 2.11 acres Scale Factor: 1.00 15-F in Reduced Edit Flows Paths Time Series: dev-15.tsf », Compute Time Series Modify User Input File for computed Time Series [.TSF] Flow Frequency Analysis Time Series File:dev-15.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.657 6 8/27/01 18:00 0.464 8 1/05/02 15:00 1.41 2 12/08/02 17:15 0.529 7 8/23/04 14:30 0.791 4 11/17/04 5:00 0.783 5 10/27/05 10:45 0.916 3 10/25/06 22:45 2.00 1 1/09/08 6:30 Computed Peaks -----Flow Frequency Analysis ------- - - Peaks - - Rank Return Prob (CFS) Period 2.00 1 100.00 0.990 1.41 2 25.00 0.960 0.916 3 10.00 0.900 0.791 4 5.00 0.800 0.783 5 3.00 0.667 0.657 6 2.00 0.500 0.529 7 1.30 0.231 0.464 8 1.10 0.091 1.80 50.00 0.980 Q100y overflow = 2.00 cfs 12" riser overflow capacity with head = 0.35' Q orifice = 3.728 * D** (2) * H ** (1/2) = 3.728 * 1 * 0.35 ** (1/2) = 2.21 cfs > 2.00 cfs, o. k. The 12" riser has the capacity to handle the 100 year overflow. 36 Since the vault is located at a sloped area, fill over the top of the vault varies from 0.5 to 85, engineering foam (Geofoam EPS46 or equal) is used to reduce the weight loading to the top of the vault. A service driveway is provided to access to the two 5'x10' grate openings and other manhole covers. The driveway is designed to support the weight of a vactor truck (60,000 pounds). At the southeast corner of the vault, there is up to 8.5' of fill over the top of the vault. Each Geofoam block is approximately 6' or 8' long x 4' wide x 1" to 3' high. Use 2 row of Geofoam 3' high blocks and 2.5' of soil on top of the Geofoam blocks. Assume a person with 300 pounds of weight is standing on top of the ground and the person's weight is distributed in a 2 square feet area. Density of the Geofoam EPS46 is 2.85 lb/cf. Soil density is 100 lb/cf. Total loading in a square feet area = 300/2 + 6 * 2.85 + 2.5 * 100 = 417.1 pounds. Compressive resistance of the Geofoam EPS 46 is 18.6 psi = 2,678.4 pounds/square feet at 1 % deformed which is larger than 417.1 pounds, o.k. 4" perforated footing drain will be used near the bottom of the Geofoam blocks to directed ground water to the vault to prevent buoyancy problem. For the service driveway on top of the vault, asphalt pavement is used for the north portion of the driveway (4" min. HMA class 0.5" on 6" min. crushed surface top course) and grasscrete is used for the south portion of the driveway as a Flow control BMP (4" thick grasscrete, on 2" choker course on 6" crushed stone base). Minimum 2' of cover is provided between the top of the driveway to the top of the Geofoam blocks. Rear axle loading of the 60,000 pounds vactor truck is 40,000 pounds. Assume this load (8 tires) is distributed in a 5'x5' area by the time the load reaches the Geofoam blocks. Total loading in a square feet area = 40,000/25 = 1,600 pounds. Compressive resistance of the Geofoam EPS 46 is 18.6 psi = 2,678.4 pounds/square feet at 1 % deformed which is larger than 1,600 pounds, o.k. Inside dimension of the vault is 90'Lx40'W (in two 20' wide cells separated by a structural wall) x 13.5' H (minimum average) to provide 8' deep live storage, 4' deep dead storage, 0.5' minimum freeboard and 1' minimum average sediment storage. Outside dimension of the vault is 921 x 43'W x 15.5' H (minimum average). The vault is designed to support the H-20 traffic loading. The majority of the vault including to two 5'x10' grated access openings are located outside the traffic paths. Only the northeast corner of the vault (with two 48" diameter access manholes and 24" diameter solid locking covers) is located in a parking area. Minimum 5' setback to the Grant Avenue South Right of way and minimum 10' setback to the closest building are provided. Vault design criteria per 2009 KCSWDM 5.3.3 is met with this design. Access requirements: 1. Two 5'x10' grated accesses and five 24" diameter solid locking covers are provided. Access openings are available within 50 feet from any location inside the vault. 2. 5'x10' removable grated accesses are provided one for each cells of the vault. 3. Both 5'x10' accesses are located outside traffic paths. Two 24" diameter solid locking manhole covers are provided in the parking area. Access ladders and hand -holds are provided at inlet and outlet pipe locations. 37 III A CONTROL 022: Foam -Control Geofoam is a cellular plastic material that is strong, but has very low density (1% of traditional earth materials). It is a manufactured in block form and meets ASTM D6817, "Standard Specification for Rigid, Cellular Polystyrene Geofoam." Foam -Control Geofoam is available in a range of Types to provide control of structural integrity and cost effectiveness. The information given is deemed to be timely, accurate, and reliable for the use of Foam -Control Geofoam. Each project using Foam -Control Geofoam should be designed by a professional engineer. The engineer or project specifications should be consulted to determine the ASTM D6817 Type required for your project loading conditions. Foam -Control Geofoam Properties ASTM D6817 Property EPS12 EPS15 EPS19 EPS22 EPS29 EPS39 EPS46 Density', min. Ib/ft3 0.70 0.90 1.15 1.35 1.80 2.40 2.85 (kg/m3) (11.2) (14.4) (18.4) (21.6) (28.8) (38.4) (45.7) Compressive Resistance12 psi 2.2 3.6 5.8 7.3 10.9 15.0 18.6 @ 1% deformation, min. psf 320 520 840 1050 1570 2160 2680 (kPa) (15) (25) (40) (50) (75) (103) (128) Elastic Modulus', psi 220 360 580 730 1090 1500 1860 min (kPa) (1500) (2500) (4000) (5000) (7500) (10300) (12800) Flexural Strength', psi 10.0 25.0 30.0 35.0 50.0 60.0 75.0 min. (kPa) (69) (172) (207) (240) (345) (414) (517) Water Absorption' by Vol. % 4.0 4.0 3.0 3.0 2.0 2.0 2.0 total immersion, max., Oxygen Index', min. Vol. % 24 24 24 24 24 24 24 Buoyancy Force Ib/ft3 61.7 61.5 61.3 61.1 60.6 60.0 59.5 (kg/m3) (990) (980) (980) (980) (970) (960) (950) ' See ASTM D6817 Standard for test methods and complete information. 2 Combined live and dead load stresses should not exceed the compressive resistance at 1% deformation. Foam -Control Geofoam is used in ground fill applications where a lightweight fill material is required to reduce stresses on underlying or adjoining soils/structures. Ready to Use. Foam -Control Geofoam maximizes onsite installation efficiency: material arrives ready to place, no weather delays, material can be prefabricated or cut at the jobsite, no staging required, material can be inventoried, production efficiency improved, and it is easy to handle. Design Loads. For most applications, long-term design loads should not exceed the linear elastic range of Foam -Control Geofoam. Combined live and dead load stresses should not exceed the compressive resistance at 1% deformation. In some specialty compressible applications, the compressive resistance at 5% and 10% deformation may be applicable. Please consult Foam -Control Geofoam Technical Bulletins for additional information. In general earthwork applications (such as levees, dikes, berms, etc.) uplift buoyancy force must be counteracted with overburden or restraint devices, such as geogrids, geomembranes, hold down devices, etc. Size and Shape. Foam -Control Geofoam is produced in block form and is easily positioned at the work site. Standards sizes: • 4' (1.2 m) widths • 8' (2.4 m) up to 16' (4.8 m) lengths • 1" (25 mm) to 36" (914 mm) thickness Other sizes and fabrication can be provided by the manufacturer. Exposure to Water and Water Vapor. The mechanical properties of Foam -Control Geofoam are unaffected by moisture. Exposure to water or water vapor does not cause swelling. Temperature Exposure/Flame Retardants. Foam -Control Geofoam is able to withstand the rigors of temperature cycling, assuring long-term performance. Although flame retardants used in the manufacture of Foam -Control Geofoam provide an important margin of safety, Foam -Control Geofoam must be considered combustible. The maximum recommended long-term exposure temperature for Foam -Control Geofoam is 165°F (74oC). Adhesives, Coatings, and Chemicals. Solvents which attack Foam -Control Geofoam include esters, ketones, ethers, aromatic, and aliphatic hydrocarbons and their emulsions, among others. If Foam -Control Geofoam is to be placed in contact with materials (or their vapors) of unknown composition, pretest for compatibility at maximum exposure temperature. Quality Assurance. Foam -Control Geofoam meets or exceeds the requirements of ASTM D6817, "Standard ASSIt& Specification for Rigid, Cellular Polystyrene UL Geofoam" Foam -Control Geofoam is monitored for Quality Control and Listed by Underwriters Laboratories Inc. Resistance to Termites, Mold, and Mildew. Foam plastics have been shown to become termite infested under certain exposure conditions. Foam -Control Geofoam with Perform Guard' provides resistance to termite OPerfformGuard' E RESISTANT infestation. Please review literature on Foam -Control Geofoam with Perform Guard for complete information. Foam -Control Geofoam will not decompose and will not support mold or mildew growth. Foam -Control Geofoam provides no nutrient value to plants or animals. Storage and Ballast. Foam -Control Geofoam stands up well to normal short-term weather conditions encountered during installation. Long-term exposure to sunlight causes yellowing and a slight embrittlement of the surface due to ultraviolet light. This has little effect on mechanical properties. If stored outdoors, cover Foam -Control Geofoam with opaque polyethylene film, tarps, or similar material. Foam -Control Geofoam should be ballasted to prevent displacement by wind or high water conditions, both in storage and during all phases of placement. Warranty. Foam -Control Geofoam Licensees offer a product warranty ensuring physical properties. '® cenvexnax_ CONTROL '. Foam -Control products are manufactured by AFM Corporation licensees. Copyright © 2015 AFM Corporation. All rights reserved. Printed in USA. Foam -Control, Perform Guard, GeoGripper, and Control, Not Compromise are registered trademarks of AFM Corporation, Lakeville, MN. ILL logo is a registered trademark of UL LLC GF05-10/15 4. 48" diameter type 1 manholes with 24" diameter locking manhole covers are used. 5. Not applied. The vault cells are 20' wide. 6. Maximum depth from the finished grade to the vault invert are within 20 feet. 7. A 5' wide x 7' high wall opening is provided at the south end of the separation wall between the two cells. 8. The minimum internal height is 13.5' in average which is larger than the required 7'. Minimum internal width is 20' which is larger than the required 4'. 9. One 5'xl0' grated removable access, three 24" diameter locking manhole covers are provided at four corners for vent. Part E Water Quality System On site improvement A treatment train of combined detention/wet vault and StormFilter manhole with CSF cartridges is used to provide the required Enhanced Basic Water Quality treatment. The StormFilter manhole with CSF cartridges will be installed downstream of the combined detention/wet vault. The combined detention/wet vault is also used as a pretreatment device for the StormFilter manhole. Wet vault sizing: Area to be treated: Total impervious area = 1.38 acres Total pervious area = 0.73 acres (till grass) Total drainage area = 2.11 acres Mean annual volume: Vr=(0.9*Ai+0.25*Atg+0.10*Atf+0.01 *Ao)*R =(0.9*1.38+0.25*0.73+0.10*0+0.01 *0)*43560*0.039 = 2,420 cf. Required dead storage = 3 * Vr = 7,260 cf. The proposed combined detention/wet vault is separated into two cells by a concrete wall in the middle, it provides 90'x40'x8' = 28,800 cubic feet of live storage, and 85' L x 40' W x 4' H = 13,600 cubic feet (> 7,260 cf, o.k.) of water quality dead storage and minimum 1' average depth of sediment storage (3,600 cubic feet). StormFilter sizing: Flow based sizing: The design WQ flow is the 2 year release rate from the combined detention/wet vault Qtreat = Q2y = 0.042 cfs = 18.86 GPM The capacity of the standard 18" high CSF cartridge is Qcart = 7.5 GPM / cartridge Nflow = Qtreat /Qcart = 2.51, Use 3 cartridges. Mass loading sizing: c: Annual average rainfall P = 38" Percent capture = 90% EMC = 60 mg/L (Seattle area commercial landuse) Area to be treated: PGIS = 1.38 acres PGPS = 0.73 acres (till grass) Mean annual runoff volume: Vt = (P in) * C * (A acres) * (43560 cf / 12 in/ft) * (% Capture) =(38)*(0.9*1.38+0.25*0.73)*(43560/12)*0.9 = 176,846 cf. Annual mass load: Mtotal = (Vt cf) * (EMC mg/L) * (28.3 L/cf) * (1 E-6 kg/mg) * (2.2046 Ibs/kg) = 176,846 * 60 * 28.3 * 1 E-6 * 2.2046 = 662 lbs. Assume pretreatment efficiency Epre = 80% (downstream of a wet vault designed to remove 80% TSS) Mpre = 662 * 0.80 = 529.60 Ibs Mpass1 = Mtotal — Mpre = 662 — 529.60 = 132.40 Ibs Assume Filter efficiency Efilter = 72% Mfilter = Mpass1 * E filter = 132.40 * 0.72 = 95.33 Ibs Mass load capacity of the standard 7.5 GPM cartridge Mcart = 36 Ibs/cartridge Nmass = Mfilter / Mcart = 95.33/36 = 2.65, Use 3 cartridges. Use the maximum number of cartridges calculated by both flow based and mass loading based sizing methods, three 18" high CSF cartridges with 7.5 gpm/cartridge capacity will be used. The cartridges will be installed in a 72" diameter StormFilter manhole. The combined detention/wet vault has two flow control devices as described in Part D, only the under two year flows drain to the StormFilter manhole, the higher flows are bypassed to a type 2 catch basin downstream of the StormFilter manhole. The 2 year release from the vault is 0.042 cubic feet per second which is less than the overflow capacity (1.5 cubic feet per second) of the StormFilter manhole. Offsite frontage improvement The offsite frontage improvement creates approximately 1,440 square feet of new impervious area (520 square feet of it is pollution generating impervious area) and no new pervious area. For flow control, the new impervious area created by the offsite improvement is counted as bypassed target area Per KCSWDM Section 1.2.3.2.E. The onsite detention vault is oversized, so that the developed onsite detained runoff plus the offsite bypassed runoff meets the required Duration standard forested site conditions flow control requirements at the point of convergence (SDMH#1 at Grant Avenue South). For water quality treatment, new pollution generating area is only 520 square feet and is counted as untreated discharge per KCSWDM Section 1.2.8.2.D bypassing the water quality treatment facilities. 39 LO co co 0 0 0 L6 T ^Q J J A I 4' C.O. W/ VALVE BOX CD FRAME & COVER r & CONC. PAD M CRASSCRETE CRASSCRETE 1' MIN NATIVE 1' MIN NATIVE SOIL BACKFILL \ SOIL BACKFlLL � 2' MIN. LL1 FILTER FABRIC ON TOP ~ AND AROUND SIDES OF GEOFOAM BLOCKS 4• PVC VERT. PIPE 1' MIN. CEOFOAM BLOCKS EPS46 OR EQUAL Fi GEOFOAM BLOCKS EPS46 OR EQUAL 5'x10' CRATED LOCKINC REMOVABLE ACCESS PANEL (MARKEO GRAIN) RIM=302.00 LLI FILTER FABRIC 4• PERF. PVC O 4• PERF. PVC 6• MIN. CRAVEL BASE _______ _-= 0 S=0.0050 6• MIN. CRAVEL BASE °"FRAME & z &LADDER OR STEPS OFFSET. SEE STEPSNOTE = 'e. 100-YEAR WATER SURFACE O TOP OF VAULT TOP OF OVERFLOW EL=299.00-fir DESIGN EL=299.00 0 EL=358.0 EL=358.VAULT 0 4• ELBOW ELEV=298.2 ° U WATER SURFACE WATER SURFACE ORIFICELu OIA=1.00' Q OESICN EL =358.4 DESIGN EL=358.4 J d 4' MAX. HICH- MODULAR CONC. Z BLOCK WALL < CEOFOAM BLOCKS EPS46 OR EQUAL BW; 306.24, 0 FINISHED GRADE 24'0 SOLID LOCKING LIO 24"0 SOLID LOCKING LIO- W/ FRAME (TYP) W/ FRAME (TYP) (MARKED DRAIN}'- `EXISTING GRADE (MARKED GRAIN) RIM=304.00 CD TOP OF VAULT _ r EL=300.5 -4• PERF. PVC, 04" PERF. PVC! ..... W - - - - LLI _ 0.5' MIN. = U -100-YEAR WATER SURFACE B, FREE80AR0 OESICN EL=299.00 LIVE STORACE 20.0' 20.0, WATER QUALITY OESICN EL=291.00 SEDIMENT STORACE 4.0' OESICN EL=287.00 DEAD STORAGE 5.0% y INV=286.25 IN 1' MIN. SEDIMENT STORAGE '5 INV=2 DETENTION VAULT SECTION (B-B) REMOVABLE WATER- TIGHT COUPLING 12" MAX 6' PLATE WITH ORIFICE OIA=1.00' 4" ELBOW DETAIL PIPE SUPPORTS (2 MIN):- 3• X .090• ALUMINUM 1'-0• W/ %- STAINLESS BOLTS MIN. 12' OUTLET PIPE 5'x10' GRATED LOCKING REMOVABLE ACCESS PANEL (MARKED GRAIN) RIM=302.00 Souo PIPE SUPPORTS (2 MIN):-"�- 3• X .090" ALUMINUM 8' SHEAR GATE W/ %- STAINLESS BOLTS MIN. till_- IE=295.65 ,,,, 12" MIN z 0 N J RESTRICTOR PLATE WITH e. ORIFICE ELEV=293.65 DRILL A 1.25• HOLE IN PLATE WELDED TO FIANCE OR DRILLED TO CAP .a FLOW RESTRICTOR TEE DETAIL NTS SCALE: 1" - 5' ASPHALT SERVICE DRIVEWAY CRASSCRETE SERVICE DRIVEWAY CEOFOAM BLOCKS EXISTINC GRADE EPS46 OR EQUAL 24"0 SOLID LOCKING UO FINISHED GRADE W/ FRAME (TYP) TRIM OR STEPPINC TOP ROW (MARKED GRAIN) 24"0 SOLID LOCKINC UO OF CEOFOAM BLOCKS TO _ - -- _----- FINISHED CRADE W/ FRAME (TYP) MATCHFINISHED-GRADE- (MARKED ORAIN) 5'x10' CRATED LOCKING ________-SLOPE_ RIM=304.00 --" REMOVABLE ACCESS PANEL TOP OF VAULT __--'-- - MAX. DEPTH FROM RIM=302-00 F1.�.,3Q0,5---- -----------_ _ _ _ _ _ - _ - _ _ ...._. FINISHED CRADE __---- - _. - TO VAULT SHALL - "' "- - BE 20 FEET AT _ - ACCESS POINTS ----____--._-- ---'- 1Y FLOW RESTRICTOR TEE._-- _�--� _._ _... SEE DETAIL THIS SHEET sow 34LF 12' LCPE TO CB #14 EL=298.2 FREE80AR0 (HICH FLOW BYPASS) ORIFICE OIA.=1.00• 100-YEAR WATER SURFACE _ 8• SHEAR GATE OESICN EL=299.00 -CIE =295.6 FlCE EL=293.65 - LIVE STORAGE 5'x7' OPENING 1Y FLOW RESTRICTOR TEE -.-----.,WATER ORIFICE OIA.=1.25' QUALITY 5' W/ SOLID TOP 8' SHEAR GATE J OESICN EL.=291.00 / - 7' _ SEDIMENT STORAGE 4.0' 289.00 ORIFICE OIA.=0.68• OESICN EL=287.00 - DEAD STORACE 27LF 12• LCPE 2' LCPE TO STORMFILTER 1' MIN. SEOIMENT STORACE FROM C8 FROM C8 #1 MANHOLE _.1.675 FRAME &LADDER OR STEPS OFFSET. SEE NOTE 8. To0-YEAR WATER SURFACE DESIGN EL=299.00 8• SHEAR CATE _1 27" 0IJTLL7 PIPE WATER QUALITY DESIGN EL=291.00 IE=291.00 RESTRICTOR PLATE WITH e. ORIFICE ELEV=290.00 DRILL A 0.6B' HOLE IN PLATE WELDED TO FIANCE OR ORILLEO TO CAP •a e e , a FLOW RESTRICTOR TEE DETAIL \INV.L285.00 Qu M y- UC 1 CIV I IVIV VAUL_ 1 SCC.: 1 IVIV ILA -A) SCALE- 1' = 5' r Pacific� r�rJ _ �. « .+ 1•=20. CITY OF RENTON �, q 1 J. HOPPER Design, I ±� ss�pslsiE �� 2 SECOND ROUND CITY REVIEW COMMENTS IF 4 JH - E yApylyy II F NAL 1 FIRST ROUND CITY REVIEW COMMENTS AL 2 1 JH o� a�� DATUM planning/building/Public Works Dept. 1 rCivil Lnglneerlr�g 1 4 /i/1 J. HOPPER . u ac wo Planning ConsuJtanss NO. REVISION BY DATE APPR NTS R-391011 APPROVED FOR CONSTRUCTION SUBJECT TO ERRORS AND OMISSIONS BY: DATE: BY- DATE: BY- DATE: BY- DATE: GRANT PLACE TOWNHOMES VAULT PLAN Ln CD CD CD CD CD Ln Q J I• U) W O Z O I- W U J CL I- Z Q 0 0 rn 0 �r 0 w I- w 2 O 2 Z O I- w U Q J d. z Q 'IT v v I- LLI W rrr^ VJ _Design, 41 j d civil Hnginesring a Planning Csnsvl_arris OUTLET SUMP J OUTLET TYID_MAN SESLABAC ESS \Tj CDVERDETAIL PLAN VIEW STANDARD OUTLET RISER FLDWMT: 42A CONiRACTORTDGRGUTTO RIM=300.56 FINISHED GRADE GRADE RINGIRISERS FLOATABLES STDRMFILTER CARTRIDGE BAFFLE INSIDE INLET PIPE HYDRAULIC ORDP (H)INLET INV. TO DUR.ET INV. FLOW KR —_ Or,%Qp M. HOpAF A _NAILTE HOPE DUTLET RISER SECTION A -A StarmFilter� 12' LCPE INV. 2BB.57 STORMFILTER DESIGN NOTES STDRMFILTER TREATMENTCAPACITY IS A FUNCTION OF THE CARTRIDGE SELECTION AND THE NUMBER OF CARTRIDGES. THE STANDARD MANHDLE STYLE IS SHOWN WRH THE MAXIMUM NUMBER OF CARTRIDGES VI VOLUME SYSTEM IS ALSO AVAILABLE WITH MAXIMUM T CARTRIDGES. 072' MANHOLE STDRMFILTER PEAK HYDRAULIC CAPACITY IS 1.5 CFS. IF THE STIE CONDmDNS EXCEED 15 CFS AN UPSTREAM BYPASS STRUCTURE IS REQUIRED, CARTRIDGESELECTION CARTRIDGE HEIGHT I 2T 16' LOW DROP RECOMMENDED HYDRAULIC DROP(H) 3D5' 23' 1A. SPECIFIC FLOW RATE PMS 2 gpmlR' l gp— 1 2 S,m 1 dind"' 2 SIP— 19PmM' CARTRIDGE FLOW RATE(9Pm) -B 1125 15 TS 10 5 SITE SPECIFIC DATA REQUIREMENTS STRUCTURE ID SF#1 WATER DUALITY FLOW RATE cfs B092 PEAK FLOW RATE cFs 0.092 RETURNPERIDDDFPEAKFLOW 2 #DFCARTRIDGESREQUIRED 3 CARTRIDGE FLOW RATE 175GMP MEDIA TYPE CEF, PERLFIE_ Z , GAC, PHS I CSF PIPE WTA: I.E. 1 MATFRA. DIAMETER INLET PIPE#1 290.87 LCPE 12' INLET PIPE#2 WA I WA WA OUTLET PIPE 26B.S/ LCPE 12' RIM ELEVATION 3mm ANT4FLDTATION BALLAST WIDTH 6' HEIGHT 2' NOTESISPECIAL REQUIREMENTS: ' PER ENGINEER OF RECORD GENERAL NOTES 1. CONTECH TO PROVIDE ALL MATER UNLESS NOTED OTHERWISE. 2. DIMENSIONS MARKED WRH () ARE REFERENCE DIMENSIONS. ACTUAL DIMENSIONS MAY VARY. 3. FOR SITE SPECIFIC DRAWINGS WITH DETAILED VAULT DIMENSIONS AND WEIGHTS, PLEASE CDNTACTYOUR CONTECH ENGINEERED SOLUTIONS LLC REPRESENTATIVE. w+.w,�.=m 4. STORMFILTER WATER QUALITY STRUC E SHALL BE IN ACCORDANCE WTTH ALL DESIGN DATA AND INFDRMATIDN CONTAINED IN THIS DRAWING. 5. STRU RESHALLMEETAASHTDHS2BLOADRATING,ASSUMINGEARTHCOVEROFT-6ANDGRDUNDWATERELEVATIONAT,DRBELDW,THE OUTLET PIPEINVENTELEVATIDN. ENGINEEROFRECDRDTOCONFIRMACRIALGRDUNDWATERELEVATION. CASTINGSSHALLMEETAASHTD M33B AND BE CAST WITH THE CONTECH LOGO. 6. FILTER CARTRIDGES SHALL BE MEDIA-FILLED_PASSIVE. SIPHON ACTUATED, RADIAL FLOW, AND SELF CLEANING. RADIALMEDIADEPTHSHALL BE 7-INCHES. FILTER MEDIA CDNTACTTIME SHALL BE AT LEAST 39 SECDNDS. T. SPECIFIC FLDWRATE IS EOUALTD THE FILTERTREATMENTCAPACITY(gpm) DIVIDED BYTHE FILTERCONTACTSUREACEAREA(a t). INSTALLATION NOTES i. ANYSUBAASE,BACK lL DEPTH,AND/DRANTFFLOTATIDNPRDVISIONSAREST PECIFICDESIGNCONSIDE nONSANDSHALLBE SPECIFIED SY ENGINEER DF RECORD. 2. CONTRACTDRTO PROVIDE EQUIPMENT WITH SUFFICIENT LIFTING AND REACH CAPACITY TO LIFT AND SETTHE STORMFILTER STRUCTURE (LIFTING CLUTCHES PROVIDED). 3.CNTRACTORTDINSTALLJOINTSEALANTBETWEENALLSTRUMN SECnONSANDASSEMBLESTRIJCTURE. 4. CDNTRACTORTDPRDVIDE,INSTALL,ANDGROUTINLETPIPE(S). 5. CDNTRACTORTO PRDVIDEAND INSTALL CONNECTOR TO THE OUTLET RISER STUB. STDRMFILTEREQIJIPPEDWITHADUALDIAMFTERHDPE OUTLET STUB AND SAND COLLAR. IF OUTLET PIPE IS LARGER THAN B INCHES, CONTRACTOR TO REMDVE THE B INCH OURET STUB AT MDLDED IN CUT LINE. COUPLING BY FERNCO OR EQUAL AND PROVIDED BY CONTRACTDR 6 CONTRACTOR TO TAKE APPROPRIATE MEASURES TO PROTECT CARTRIDGES FROM CONSTRUCTION -RELATED EROSION RUNOFF. 10- CITY OF cRFFrL 1'-20• B�,B9,1## �� >,- R EN TO N 2 SECOND ROUND qTY REVIEW COMMENTS JF 4"APPR E MMSIWL DATUM 1 MRST ROUND qTY REVIEW COMMENTS AL 2 Planning/Building/Public Works Dopt. N0. REVISION 8Y DAT� 'r"'°f°1°'1°1f R-391012 APPROVED FOR CONSTRUCTION SUBJECT TO ERRORS AND OMISSIONS BY: DATE: . BY: DATE: . BY: DATE: . BY: DATE: . GRANT PLACE TOWNHOMES STORMALTER MANHOLE DETAILS LO OD OD O 0 O 1 LO T Q J I W 2 O Z O I- W U Q J d Z Irr V. Conveyance System Analysis and Design Conveyance system is designed per section 1.2.4.1 of 2009 City of Renton Surface Water Design Manual Amendment to convey the 25-year developed peak flow with minimum 6 inches of free board and check for overflow for developed 100-year peak flow and shall not cause downstream property damage in case overflow happens in 100-year storm event. Use rational method to calculate the 25 year and 100 year 24 hour peaks QR=C*IR*A IR=PR*iR PR = 3.40 inch for 25 year storm = 3.90 inch for 100 year storm iR=aR*TCA(-bR) Tc = Time of concentration = 6.3 minutes for small areas aR bR iR for Tc = 6.3 minutes IR for Tc = 6.3 minutes 25 year 2.66 0.65 0.804 2.734 100 year 2.61 0.63 0.819 3.194 Onsite storm network: The onsite storm can be divided into three pipe networks. King County backwater method is used to verify the capacity of the proposed conveyance systems. Network #1 collects and conveys runoff from upstream tributary area east of the site, roof and sidewalks of the two east buildings, pavements of the east and north public alleys and landscape areas north of these two alleys. Total drainage area = 0.886 acres. Total impervious area = 0.482acres (C = 0.9) Total pervious area = 0.404 acres (till grass, C = 0.25) Q25y=C*IR*A=(0.90*0.482+0.25*0.404)*2.734=1.46cfs Q1 00y = C * IR * A = (0.90 * 0.482 + 0.25 * 0.404) * 3.194 = 1.71 cfs BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:Nl.bwp Surcharge condition at intermediate junctions Tailwater Elevation:299. feet Discharge Range:1.46 to 1.71 Step of 0.25 [cfs] Overflow Elevation:355. feet Weir:NONE Upstream Velocity:l. feet/sec PIPE NO. 1: 24 LF - 12"CP @ 47.92% OUTLET: 289.00 INLET: 300.50 INTYP: 5 JUNC NO. 1: OVERFLOW -EL: 303.50 BEND: 90 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.13 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 1.46 0.53 301.03 * 0.012 0.52 0.16 10.00 10.00 0.52 ***** 0.53 Q100 1.71 0.61 301.11 * 0.012 0.56 0.18 10.00 10.00 0.56 ***** 0.61 At CB#8 For 25-year peak 303.50 - 301.03 = 2.47 > 0.5, o.k. For 100-year peak 303.50 - 301.11 = 2.39 > 0.0, o.k. PIPE NO. 2: 82 LF - 1211CP @ 14.67% OUTLET: 300.50 INLET: 312.53 INTYP: 5 SUNC NO. 2: OVERFLOW -EL: 315.53 BEND: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.14 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 1.29 0.59 313.12 * 0.012 0.49 0.20 0.53 0.53 0.49 ***** 0.59 Q100 1.51 0.65 313.18 * 0.012 0.53 0.22 0.61 0.61 0.53 ***** 0.65 At CB#9 For 25-year peak 315.53 - 313.12 = 2.41 > 0.5, o.k. For 100-year peak 315.53 - 313.18 = 2.35 > 0.0, o.k. PIPE NO. 3: 87 LF - 1211CP @ 4.05% OUTLET: 312.53 INLET: 316.05 INTYP: 5 SUNC NO. 3: OVERFLOW -EL: 319.05 BEND: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.17 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 1.13 0.60 316.65 * 0.012 0.45 0.26 0.59 0.59 0.45 ***** 0.60 Q100 1.33 0.66 316.71 * 0.012 0.49 0.28 0.65 0.65 0.49 ***** 0.66 At CB#10 For 25-year peak 319.05 - 316.65 = 2.40 > 0.5, o.k. For 100-year peak 319.05 - 316.71 = 2.34 > 0.0, o.k. PIPE NO. 4: 104 LF - 12"CP @ 7.64% OUTLET: 316.05 INLET: 324.00 INTYP: 5 SUNC NO. 4: OVERFLOW -EL: 327.00 BEND: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.20 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.97 0.53 324.53 * 0.012 0.42 0.21 0.60 0.60 0.42 ***** 0.53 Q100 1.13 0.58 324.58 * 0.012 0.45 0.23 0.66 0.66 0.45 ***** 0.58 At CB#ll For 25-year peak 327.00 - 324.53 = 2.47 > 0.5, o.k. For 100-year peak 327.00 - 324.58 = 2.42 > 0.0, o.k. PIPE NO. 5: 106 LF - 12"CP @ 7.63% OUTLET: 324.00 INLET: 332.09 INTYP: 5 SUNC NO. 5: OVERFLOW -EL: 335.09 BEND: 30 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.25 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.81 0.48 332.57 * 0.012 0.38 0.19 0.53 0.53 0.38 ***** 0.48 Q100 0.95 0.53 332.62 * 0.012 0.41 0.21 0.58 0.58 0.41 ***** 0.53 At CB#12 For 25-year peak 335.09 - 332.57 = 2.52 > 0.5, o.k. For 100-year peak 335.09 - 332.62 = 2.47 > 0.0, o.k. PIPE NO. 6: 44 LF - 1211CP @ 11.05% OUTLET: 332.09 INLET: 336.95 INTYP: 5 SUNC NO. 6: OVERFLOW -EL: 340.61 BEND: 30 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.33 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ******************************************************************************* Q25y 0.65 0.41 337.36 * 0.012 0.34 0.16 0.48 0.48 0.34 ***** 0.41 Q100 0.76 0.45 337.40 * 0.012 0.37 0.17 0.53 0.53 0.37 ***** 0.45 At CB#13 For 25-year peak 340.61 - 337.36 = 3.25 > 0.5, o.k. For 100-year peak 340.61 - 337.40 = 3.21 > 0.0, o.k. PIPE NO. 7: 52 LF - 1211CP @ 8.94% OUTLET: 336.95 INLET: 341.60 INTYP: 5 SUNC NO. 7: OVERFLOW -EL: 344.33 BEND: 70 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.50 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.49 0.35 341.95 * 0.012 0.29 0.14 0.41 0.41 0.29 ***** 0.35 Q100 0.57 0.39 341.99 * 0.012 0.32 0.16 0.45 0.45 0.32 ***** 0.39 At CB#6 For 25-year peak 344.33 - 341.95 = 2.38 > 0.5, o.k. For 100-year peak 344.33 - 341.99 = 2.34 > 0.0, o.k. PIPE NO. 8: 111 LF - 12"CP @ 6.56% OUTLET: 341.60 INLET: 348.88 INTYP: 5 41 JUNC NO. 8: OVERFLOW -EL: 351.60 BEND: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 1.00 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.32 0.29 349.17 * 0.012 0.24 0.13 0.35 0.35 0.24 ***** 0.29 Q100 0.38 0.31 349.19 * 0.012 0.26 0.14 0.39 0.39 0.26 ***** 0.31 At CB# 7 For 25-year peak 351.60 - 349.17 = 2.43 > 0.5, o.k. For 100-year peak 351.60 - 349.19 = 2.41 > 0.0, o.k. PIPE NO. 9: 15 LF - 1211CP @ 7.47% OUTLET: 348.88 INLET: 350.00 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.16 0.17 350.17 * 0.012 0.17 0.09 0.29 0.29 0.17 ***** 0.17 Q100 0.19 0.19 350.19 * 0.012 0.18 0.10 0.31 0.31 0.18 ***** 0.19 At CB# 18 For 25-year peak 355.00 - 350.17 = 4.83 > 0.5, o.k. For 100-year peak 355.00 - 350.19 = 4.81 > 0.0, o.k. All catch basins of network #1 have more than 6 inches of free board for 25-year storm peak and no overflow happen for 100-year storm peak. Network #2 collets and conveys runoff from the pavement of the south public alley, pervious area from Tract C and landscape areas east and south of the south public alley. Total drainage area = 0.474 acres. Total impervious area = 0.284 acres (C = 0.9) Total pervious area = 0.190 acres (till grass, C = 0.25) Q25y = C * IR * A = (0.90 * 0.284 + 0.25 * 0. 190) * 2.734 = 0.83 cfs Q1 00y = C * IR * A = (0.90 * 0.284 + 0.25 * 0. 190) * 3.194 = 0.97 cfs BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:N2.bwp Surcharge condition at intermediate junctions Tailwater Elevation:299. feet Discharge Range:0.83 to 0.97 Step of 0.14 [cfs] Overflow Elevation:333.6 feet Weir:NONE Upstream Velocity:l. feet/sec PIPE NO. 1: 34 LF - 1211CP @ 39.06% OUTLET: 289.00 INLET: 302.28 INTYP: 5 JUNC NO. 1: OVERFLOW -EL: 305.28 BEND: 90 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.25 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.83 0.39 302.67 * 0.012 0.39 0.13 10.00 10.00 0.39 ***** 0.34 Q100 0.97 0.42 302.70 * 0.012 0.42 0.14 10.00 10.00 0.42 ***** 0.40 At CB#1 For 25-year peak 305.28 - 302.67 = 2.61 > 0.5, o.k. For 100-year peak 305.28 - 302.70 = 2.58 > 0.0, o.k PIPE NO. 2: 60 LF - 1211CP @ 14.58% OUTLET: 302.28 INLET: 311.03 INTYP: 5 JUNC NO. 2: OVERFLOW -EL: 314.03 BEND: 10 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.33 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25 0.66 0.39 311.42 * 0.012 0.34 0.15 0.39 0.39 0.34 ***** 0.39 Q100 0.78 0.43 311.46 * 0.012 0.37 0.16 0.42 0.42 0.37 ***** 0.43 At CB#2 For 25-year peak 314.03 - 311.42 = 2.61 > 0.5, o.k. For 100-year peak 314.03 - 311.46 = 2.57 > 0.0, o.k PIPE NO. 3: 90 LF - 12"CP @ 4.00% OUTLET: 311.03 INLET: 314.63 INTYP: 5 42 JUNC NO. 3: OVERFLOW -EL: 317.63 BEND: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.50 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25 0.50 0.38 315.01 * 0.012 0.30 0.18 0.39 0.39 0.30 ***** 0.38 Q100 0.58 0.42 315.05 * 0.012 0.32 0.19 0.43 0.43 0.32 ***** 0.42 At CB#3 For 25-year peak 317.63 - 315.01 = 2.62 > 0.5, o.k. For 100-year peak 317.63 - 315.05 = 2.58 > 0.0, o.k PIPE NO. 4: 99 LF - 1211CP @ 7.34% OUTLET: 314.63 INLET: 321.90 INTYP: 5 JUNC NO. 4: OVERFLOW -EL: 324.90 BEND: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 1.00 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25 0.33 0.29 322.19 * 0.012 0.24 0.13 0.38 0.38 0.24 ***** 0.29 Q100 0.39 0.31 322.21 * 0.012 0.26 0.14 0.42 0.42 0.26 ***** 0.31 At CB#4 For 25-year peak 324.90 - 322.19 = 2.71 > 0.5, o.k. For 100-year peak 324.90 - 322.21 = 2.69 > 0.0, o.k PIPE NO. 5: 108 LF - 12"CP @ 8.05% OUTLET: 321.90 INLET: 330.59 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.17 0.17 330.76 * 0.012 0.17 0.09 0.29 0.29 0.17 ***** 0.17 Q100 0.19 0.19 330.78 * 0.012 0.19 0.10 0.31 0.31 0.19 ***** 0.19 At CB#5 For 25-year peak 333.60 - 330.76 = 2.84 > 0.5, o.k. For 100-year peak 333.60 - 330.78 = 2.82 > 0.0, o.k All catch basins of network #2 have more than 6 inches of free board for 25-year storm peak and no overflow happen for 100-year storm peak. Network #3 collets and conveys runoff from the roof and sidewalk of the six central buildings and landscape areas in the central area. Total drainage area = 0.763 acres. Total impervious area = 0.477 acres (C = 0.9) Total pervious area = 0.286 acres (till grass, C = 0.25) Q25y=C*IR*A=(0.90*0.477+0.25*0.286)*2.734=1.37cfs Q100y=C*IR*A=(0.90*0.477+0.25*0.286)*3.194=1.60cfs BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:N3.bwp Surcharge condition at intermediate junctions Tailwater Elevation:299. feet Discharge Range:1.37 to 1.6 Step of 0.23 [cfs] Overflow Elevation:329.9 feet Weir:NONE Upstream Velocity:l. feet/sec PIPE NO. 1: 31 LF - 1211CP @ 75.48% OUTLET: 289.00 INLET: 312.40 INTYP: 5 JUNC NO. 1: OVERFLOW -EL: 315.48 BEND: 30 DEG DIA/WIDTH: 2.0 Q-RATIO: 0.50 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 1.37 0.50 312.90 * 0.012 0.50 0.14 10.00 10.00 0.50 ***** 0.33 Q100 1.60 0.54 312.94 * 0.012 0.54 0.15 10.00 10.00 0.54 ***** 0.40 At CB#15 For 25-year peak 315.48 - 312.90 = 2.58 > 0.5, o.k. For 100-year peak 315.48 - 312.94 = 2.54 > 0.0, o.k 43 PIPE NO. 2: 121 LF - 12"CP @ 5.54% OUTLET: 312.40 INLET: 319.10 INTYP: 5 JUNC NO. 2: OVERFLOW -EL: 322.10 BEND: 0 DEG DIA/WIDTH: 2.0 Q-RATIO: 1.00 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.91 0.53 319.63 * 0.012 0.41 0.22 0.50 0.50 0.41 ***** 0.53 Q100 1.07 0.59 319.69 * 0.012 0.44 0.24 0.54 0.54 0.44 ***** 0.59 At CB#16 For 25-year peak 322.10 - 319.63 = 2.47 > 0.5, o.k. For 100-year peak 322.10 - 319.69 = 2.41 > 0.0, o.k PIPE NO. 3: 103 LF - 12"CP @ 7.57% OUTLET: 319.10 INLET: 326.90 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.46 0.33 327.23 * 0.012 0.28 0.15 0.53 0.53 0.28 ***** 0.33 Q100 0.53 0.36 327.26 * 0.012 0.31 0.16 0.59 0.59 0.31 ***** 0.36 At CB#17 For 25-year peak 329.90 - 327.23 = 2.67 > 0.5, o.k. For 100-year peak 329.90 - 327.26 = 2.64 > 0.0, o.k All catch basins of network #3 have more than 6 inches of free board for 25-year storm peak and no overflow happen for 100-year storm peak. Network #4 (From 15" CMP culvert downstream existing CB SDMH#1 at Grant Avenue South to onsite detention/wet vault outfall pipe upstream of CB#14): The Grant Avenue South storm drainage network at the frontage of the site collects runoff from 4 drainage sub -basins. Sub -basin #1: The site (2.11 acres) plus the upstream tributary area east of the site (0.22 acres). The 25-year and 100-year detention/wet vault release rates are: Q25y = 0.127 cfs Q100y = 0.258 cfs Sub -basin #2: The Heritage Village Condo property south of the site (1.86 acres) This development was built around 1988 using Level 1 Flow Control Standard. A 57LF 96" diameter detention tank was installed for flow control and the tank is still existing. Assume the design was to match existing condition before 1979 which was a single family condition (C = 0.35). Q25y=C*IR*A=0.35*2.734*1.86=1.78cfs Q100y=C*IR*A=0.35*3.194*1.86=2.08cfs Sub -basin #3: The Puget Sound Energy property north of the site (tributary area 8.38 acres, C=0.2 for pasture) Q25y=C* I R * A = 0.20 * 2.734 * 8.38 = 4.58 cfs Q100y=C*IR*A=0.20*3.194*8.38=5.35cfs Sub -basin #4: Grant Avenue South Right of way Total area = 0.75 acres 44 Total impervious area = 0.55 acres (C=0.9) Total pervious area = 0.20 acres (till grass, C = 0.25) Q25y = C * IR * A = (0.55*0.9 + 0.20*0.25) * 2.734 = 1.49 cfs Q100y = C * IR * A = (0.55*0.9 +0.20*0.25) * 3.194 = 1.74 cfs The 25-year and 100-year peak flows at the 15" CMP culvert downstream of existing catch basin SDMH#1 are: Q25y=0.127+1.78+4.58+1.49=7.98cfs Q100y=0.258+2.08+5.35+1.74=9.43cfs BACKWATER COMPUTER PROGRAM FOR PIPES Pipe data from file:OS.bwp Surcharge condition at intermediate junctions Tailwater Elevation:282.99 feet Discharge Range:7.98 to 9.43 Step of 1.45 [cfs] Overflow Elevation:302. feet Weir:NONE Upstream Velocity:l. feet/sec PIPE NO. 1: 48 LF - 15"CMP @ 9.60% OUTLET: 281.99 INLET: 286.60 INTYP: 5 JUNC NO. 1: OVERFLOW -EL: 294.54 BEND: 0 DEG DIA/WIDTH: 4.0 Q-RATIO:35.55 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 7.98 2.46 289.06 * 0.024 1.12 0.80 1.00 1.00 1.12 ***** 2.46 Q100 9.43 3.13 289.73 * 0.024 1.17 0.91 1.00 1.00 1.17 ***** 3.13 At existing catch basin SDMH#[1 at Grant Avenue South For 25-year peak 294.54 - 289.06 = 5.48 > 0.5, o.k. For 100-year peak 294.54 - 289.73 = 4.81 > 0.0, o.k PIPE NO. 2: 50 LF - 1211CP @ 2.32% OUTLET: 287.34 INLET: 288.50 INTYP: 5 JUNC NO. 2: OVERFLOW -EL: 296.27 BEND: 45 DEG DIA/WIDTH: 4.0 Q-RATIO: 0.00 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI *********************************************************************************** Q25y 0.22 0.57 289.07 * 0.012 0.20 0.14 1.72 1.72 0.57 0.57 0.25 Q100 0.26 1.24 289.74 * 0.012 0.21 0.15 2.39 2.39 1.24 1.24 0.27 At new catch basin CB#[14 For 25-year peak 296.27 - 289.07 = 7.20 > 0.5, o.k. For 100-year peak 296.27 - 289.74 = 6.53 > 0.0, o.k PIPE NO. 3: 34 LF - 1211CP @ 7.35% OUTLET: 288.50 INLET: 291.00 INTYP: 5 Q(CFS) HW(FT) HW ELEV. * N-FAC DC DN TW DO DE HWO HWI ************************************************************************************ Q25y 0.22 0.21 291.21 * 0.012 0.20 0.10 0.57 0.57 0.20 ***** 0.21 Q100 0.26 0.23 291.23 * 0.012 0.21 0.11 1.24 1.24 0.21 ***** 0.23 At northwest corner of new detention/wet vault For 25-year peak 302.00 - 291.21 = 10.79 > 0.5, o.k. For 100-year peak 302.00 - 291.23 = 10.77 > 0.0, o.k All catch basins of network #4 have more than 6 inches of free board for 25-year storm peak and no overflow happen for 100-year storm peak. «1 / CB #14 O NOTES CB-11 (HIGH FLOW BYPASS) f '� _ 14LF 12" LCPE- O FOR NEW STORM DRAIN RIMS AND INVERTS - - MANHOLE / M SEE PROFILE AND STRUCTURE TABLE ON I SFMH#1 WICSF CARTRIDGES ' O SHEET CD9 CB #8 82LF/12" LCPE FOR EXISTING STORM DRAINAGE SYSTEM I SDLF 3 LOPE ALONG GRANT AVENUE AND OTHER OFFSITE g - - - "- 300 BW-304 STORM DRAINAGE SYSTEM SEE SHEET CD2 ' M , \ (Z ® Bw _ w " FOR STANDARD STORM DRAIN MATERIALS S H-1 I' AND DETAILS SEE CITY OF RENTON \ j STANDARD DETAIL PLANS \ - ALL ONSITE WALKWAYS TO BE POROUS PAVEMENT, TOTAL 9,D31 SF. SEE SHEET C14 FOR DETAIL OYP.) PUBLIC WATER EASEMENT (FROM R.O.W. LINE TO 'fU CB #13 CB #9 87LF 12" LCPE CB #10 1D4LF 12" LCPE tD6LF 12"�LCPE Bw-34o , - Ili �m_..e / BW=3t m BW--D-_---'- 23LF 6" m f rHw s CALC89 CUT: 2,. DD CU YD FILL, 2JZOO CU YD NET: - 1DD CU YD [CUT] 54 ALL WALLS EXCEEDING 4 FEET IN HEIGHT SS.:.: ;;;. ` S ::: :� �` ��4b H I wl l 15 'T2�' CPE WILL REQUIRE SEPARATE BUILDING PERMITS. 1ST F� I15T FF 1ST rF= ItsT FF=1 tsr FF-IR DETENTION VAULTS WILL REQUIRE SEPARATE INGRESS EGRESS AND LTIY+ (QEASEMENT TO BE OBTAINS i asDO ass 13s�.0 3sasw BUILDING PERMIT. FROM PSE '` I 1 T - � 2NJ8FF NO FF- ND - N6 .0 NO FF- L STORM DRAINS IN ALLEY TO BE PUBLI0. 1ST FF-1ST FF- 1ST IT= 1ST FF-' 1ST FF- IST FF= 1ST FF- 1ST FF= 'iST FF= 1ST FF=1ST FF= 1ST FF= 3350 3585 12360.0 123615 �363.0 z3SEE SHEET CD3 FOR CITY EASEMENT ON 34U 12" LCPE '•"'`F' 3tD 1I 317.5 1 3175 1 "9-D 324.0 1325.5 325.5 3320 1333.5 I 333.5 I2N0 FF= :: LCPE 345.0 O TRACT A FOR VAULT MAINTENANCE, SIGNS1D' WIDE TYPE Ci AND ONE WAY ARROWS ON PAVEMENT C#15DRIVEWAY PER RENTON o+DD z ALONG PUBLIC ALLEY. STD PLAN 1D4 `C tu " - FLOW CONTROL BMPS USED \ , r �_I 1sT FF= 11sr FF=I s FF I BW-352 � IX7S11NG ¢ R.O.W. � wXp 6 I w ONSITE PERVIOUS CONCRETE SIDEWALK=9,D31 SF. otw3oe - -` t3 F GRASSCRETE VAULT ACCESS DRIVEWAY=1,973 SF. CB#17 50.0 3sts 353FF 3sa.5 I QU \ 121 12" (PR ATE) 1D3LF 1 LCPE PRNA I I 2No 12ND .0 1zND..5 1236 .0 12ND .5 TREE PRESERVATION (TRACT C) = 2,595 SF. COMBINED PUBLIC DETEMION/WET 1 g" I( �) 1ST F5- 358. 360.0 361.5 363A 36e,5 VAULT .t1. 31LF 12" LGIPE RATE) _ 1ST FF_ 1ST FF- 1ST fF 1ST FF= 1ST FF= I iS3z.0 11ST IJ 333.5 1 I I I _ 1 O• \' 1ST F- ItST FF-1 . `F= 11ST FF-I 1ST FF= - I - I 1 p CONSERVATION FLOW CONTROL e' DEEP LIVE STORAGE \ 6� 3 322.0 323.5 323.5 325.0 3:50.5 332.0 332.0 2ND FF= Y 2B,BDDCF TOTAL PROVIDED ` 3145 316.0 316.0 376.0 317.5.' 343.5 F_ FACILITY 2B,767CF REQUIRED S"D I c INSTALL OD CO 4' DEEP DEAD STORAGE \ �I� EAST P EG O < PUBLIC COMBINED DETENTION/WET VAULT. 13,6DDCF TOTAL PROVIDED Do NC :; N. ? _ P 7,26DCF REQUIRED : \ -'; g=1+�-i� J "SHEETS 13 FOf� O CD ENHANCED BASIC WO FACILITY EX. STREET LIGHT TO N�;. ' SS SS S .::. S - - _ - -- - - - -- - DETAI I ' L�j S - ew-347 REMAIN ,. ... :. ...... .- - - - - _�. TREATMENT TRAIN OF PUBLIC COMBINED �a / '_. CB #S - - Q DETENTION/WET VAULT AND STORMFILTER 2D' WIDE TYPE C18 \ - CB #2 BWm338 BW-338 MANHOLE W/CSF CARTRIDGES. DRIVEWAY PER RENTON \OMH-a CB #3 CB #4 tD+4J ''�. 1D' WIDE TYPE Cl 99LF 1Y LCPE 1D8LF 12" LCPE 23LF 6" LCPE I J STD PLAN 1D4.4, ,-"-= DRIVEWAY PER RENTON 9DLF 12" LCPE INSTALL WOOD: FENCE SIDEWALK AT DRIVEWAY STD PLAN 1D4 R.O.W. LINE ALONG SOUTH PROPE 1 CROSSING SHOULD NOT 6DLF 12" LCPE UNE, SEE SHEET C13 CO BE DEPRESSED AT cg a \ n1ET111lORK /,c2 FOR OETAIL O LOCATIONS WHERE // - \ 34LF 12" LCPE NETWORK V U FC T� 7t I- LANDSCAPING IS MORE DOS77NG CURB ce_asDM o1A CB #1 - 30 0 110 20 30 60 w THAN 5 FEET WIDE TOTAL AREA=0.474 AC. w NETWORK#3 ,� _ IMPERVIOUS AREA=0.284 AC.GROHICSCALE °' TOTAL AREA=0.763 AC. PERVIOUS AREA=0.190 AC. S4LE11"-W' 6D' PUBLIC R.O.W. I IMPERVIOUS AREA=0.477 AC. �, R.O. 31.5' PUBLIC 1/2 R.D.W. .5' 21' PUBLIC R.D.W. (TILL GRASS) NETWORK#1 30' 3D' y I 5' SIDEWALK PERVIOUS AREA=0.286 AC. 3 3 (TILL GRASS) 2D' TRAVELLED WAY o o TOTAL AREA=0.866 AC. o 1.5' R.O.W. DEDICATION I I 5' PRIVATE SIDE 35.87't TRAVELLED WAY (VARIES) 8' w i1w �i 2D' TRAVELLED WAY I� IMPERVIOUS AREA-0.482 AC. EXISTING ANDSCAPE cn I v1 18 0 SID WALK CONCRETE ' o I 7D' 1D' 0 1D' L 1D' I. SIDEWALK CDN - :O SIDEWALK EXISTING 10' L 1D' L SIDEWALK K CONCRETE _ _ CURB (TYPICAL) EXISTING 6" 27 1.5 4; I II ;';;PERVIOUS AREA=0.404 AC. PAVEMENT CENTER LINE DF I I 0- 1 �IPAVE NT D.6't CURB 3I I3 87 CURB 8% exI I lex 87 I CURB 8% 0 `({11\ `\\ o MAX. I 27 2% 11.5 MAX. AXI 27 2y, (MA MAX. I 2% I 2% 11.5 MAX. (TILL GRASS) I EXISTING `EXISTING `EXISTING dI Ia 2" A.0 2" A C 0 4' 2" A.0 ppp POWER STORM GAS i (o WEARING COURSE WEARING COURSE �I I I WEAR NG COURSE a WEARING COURSE Of I w a 2" AI 2" A.0 10" WATER MAIN 1,�. --I. �11". 2" A'C 12" STORM SEWER 5' iD' T 2 A.0 x EXISTING EXISTING I,I�-*� -III' BEARING COURSE 10" WATER MAN g' 5' 5' 8' BEARING COURSE 6.7't 3.3't BEARING COURSE BEARING COURSE CABLE WATER 7D" WATER MAIN 5.4't 4.3't 6" CRUSHED ROCK 12" STORM SE R 6" CRUSHED ROCK 6" CRUSHED RDCK 6" CRUSHED ROCK NDM- EXISTING UTIUTY DEPTHS ARE ASSUMED SUBGRADE SUBGRADE SUBGRADE B" SANITARY SEWER SUBGRADE GRANT AVENUE 12" STORM SEWER 8" SANITARY SEWER 12" STORM SEWER 10" WATER MAIN CROSS SECTION A NDM, PAVEMENT THICKNESS PER CDR 4-6-OBO.F.5 N= PAVEMENT THICKNESS PER CDR 4-6-060.E.5 NOTE; PAVEMENT THICKNESS PER CDR 4-6-060.F.5 NOTE; PAVEMENT THICKNESS PER CDR 4-6-060.F.5 FINAL PAVEMENT THICKNESSES PENDING FINAL PAVEMENT THICKNESSES PENDING FINAL PAVEMENT THICKNESSES PENDING FINAL PAVEMENT THICKNESSES PENDING SCALT-V GEOTECHNICAL ENGINEER'S REPORT GEOTECHNICAL ENGINEER'S REPORT GEOTECHNICAL ENGINEER'S REPORT GEOTECHNICAL ENGINEER'S REPORT 10' GRANT CIRCLE S.E. (PUBLIC ALLEY) PUBLIC ALLEY GRANT CIRCLE (PUBLIC ALLEY) GRANT CIRCLE (PUBLIC ALLEY) TEMPORARY CROSS SECTION C CROSS SECTION D CROSS SECTION E CROSS SECTION F CONSTRUCTION EASEMENT SCALE; r-V SCALE r-V SCALE r-V SCALE: r-V FROM PSE 5' 20.5' PUBLIC R.D.W. 3' 10' Z TEMPORARY -'ILI 0' TRAVELLED WAY CONSTRUCTION rl w EASEMENT cn FROM PSE 22.35' oz I z 5.83' 4' VARIES Z Ak di I I z I 4' 15.5' 3 1 w I� 4' MAX. HIGH CURB NEW ROCKERY 27 I ?3I w 0 B.D w R-391008 I ~ of lo.__.. SEE FOR DETAIL 2" A.0 SHT C14'NqX. o_I 0 3 3-- 'a APPROVED FOR CONSTRUCTION WEARING COURSE gy, 1- a9 \ SUBJECT TO ERRORS AND OMISSIONS w 4' 4' MAX. HIGH _ 2" A.0 I 1.57 MAX. MAX. 1.57 '__� 12" STORM SEWER BEARING COURSE NEW ROCKERY I 2 1D" WATER MAIN 5 10 7 SEE SHT C14 4' MAX. HIGH 6" CRUSHED ROCK NEW RDCKERIES 0 TE: SUBGRADE FDR DETAIL I I SEE SHT C14 DATE: NOPAVEMENT THICKNESS PER CDR 4-6-060.F.5 8" SANITARY SEWER 4" CONCRETE 4" CONCRETE FOR DETAIL FINAL PAVEMENT THICKNESSES PENDING SIDEWALK SIDEWALK BY: DATE: z GEOTECHNICAL ENGINEER'S REPORT GRANT CIRCLE S.E. (PUBLIC ALLEY) BY. DATE. CROSS SF_ CROSS SECTION B �QN M NOpA SCALE- G CROSS�SEECpT10N H BY, DATE: U w SCALE r-V 0°i�pF Sy/ Q 3' �� �o� T. + "'"� "° e` GRANT PLACE TOWNHOMES 2016-12-2 ev, aCHIC 1 d' t y ®m 1"=20, xania, wn i .n 4' CITY OF�, 4laMM HOI�FER `n RENTON o� E- Design, ""`�gF0ISTEP��?`" 2 SECOND ROUND CITY RENEW COMMENTS JF 4 JH E. MARsHALL �z � .. S/ORAL E�6 1 FIRST ROUND CITY RENEW COMMENTS AL 2 1 `IH - .cam, I Planning/Building/Public Works De t < C7tit Eng3nar rrU 1-7/17 J. HOPPER F „P • GRADING ROADWAY AND DRAINAGE PLAN Flannin Crr:.,a. a. N0. REVISION BY DATE APPR ""` 008 21 (Ij 7MUM NANO PLACED K/P24P GENERAL NOTES LURH INLET b'3 G.H. >G, TYPE X I, All work materials shall be in canfomance with the standards ands eclfica- bans of [M1e City of Renton Utility Department and the latest eai lion of [h< Aviv standards and Svecificatf °ns. =2TB 59 TYPE 7P-g STA. Bp40 17.17'RT -40 L.,,R/M' STA.8s40 , f7.17'LT Z94..a R/N1a290D LE. Ka64:3A B'W, 2 All la[ati vns o utsting ....... zare arazima to a d it shall be N ractor's responsibility to the true andppcorrect location zo as to f5'fi CMP /-E.=;g,..�y, g"E. AE. =t4B4:6FTy /2 5. avoid damage or disturbance. e 5.5 35L.F., B'4CMP 3. A precaast.WCHvn wnfermce and M my -four M1aor notate Will be required prlor to starting neW cvnitrvctlon.< E responsibility to secore ail necessary peons [s ztartin<°nmactnr's pr g wns[rvction. / ' � 5. Inspection Wili be acconplizhed by a representative of the City of Renton. It shall be the contractor's resDonsiptl its so n°nfy the Utility Oepartmm 21 hvur5 to ddvanc! of backftl ling all con trvc [ion. � 1 b. RLe 1 RACK A— -1-1 ,<aCX 5!L(LG 6E APPRo yEO tlV THE / / �_ � ^� 1 etTY of RENraN P raR r+e u5C aR ..� r l nl ON4 /_ RE44 1NE%R f4c//C/T/ SA% gTELtlrY/ES �+'/ y0 1N/N N PMWEG/ UM/TS N /N'LRS , — - - - � Nv caossiN4 F ur L/rres 1 i RECESSED OR/YE9AY CURB TYPE D, ^XN9 STD_ iCAX XM5` _ _ t 2X 9 � y\ ea. � A• _ SE DE � SEE DETA/L SHT 5 LE.-PB4.39 -- - --- x 2/G.F., fE^¢CMP, "-- - --'-- B1L9B% .. ,,. SEE_ ENLARGED INTERSECTION DRAWING —SHEET 6. STA. H<UO, 5' RT 4 H. 1 R, TYPE E CURB INLET R I R/M-290.-% 1.-4145, 1Z17'LS TYPE/.E--asf-oe, f2'S. R/M=905.88 $M.6f,90, IZ17'LT //s ?- 2.69, le-Ar --- r-4/ L.F., 24'¢Coma PIPE, PB3� ADJUST EX/ST. C_B. TD MArGH CURB. R/M= 3O8.9b (CityaI Re - As-BuiLts) -- MATCN INVERTS E2 L.F., B"d CMP 755 35L.F f5-¢CMP, e1..4Y iaoof > mm�n,°. REMOVE EX157' 15"GONG. V11 d• / p\` � \ ��` � 5=707 H° x tp^M1N/MUM R/PRAP W^ CURVE DATAiTABLE - RO. I DELTARADIUS LEN6iN TAN—T C-1 51° 46' 18.6'. I25.00' -: 112.949' 6R659' C-2 1 15^ 56' 04.0Y' 20000' 1 55.622' 1 27.992- C-3- 94- 51' 45.0' i 185.00` 506.298' 201.406' N W U 0� < H vi a W c� oZcf) ao a j /) Z Q vi o5 _j a C3 W o z Z3o :3 Qua 2 OF lillEm City of Renton Print map Template `egeCtyandCoanryBountlary aN W Remm� Atltlresses Parcels — 2' Primary — z' mtermaaiate Netw' � swctarea ■ _ - ■ uuuN va��r _ an ■ wk��sww�e � Control StmcNre � Pump Station Discharge Point - � Water Oualfy Detention Facilities SUB-BASIN#3 y �a TOTAL AREA = 8.38 AC. (C=0.2) i reek � vein — S[ormwater Main t � t 3 t� � Culvert 1 174@ 4 5 7 i 1414t -t7:i6 � Open Drains Virtual Drainline � Facility OWlne t 436 i 743 SUB-BASIN#1 J t Private NelworkSwctures TOTAL AREA =2.33 AC. ® a. TOTAL AREA=OJSAC. z tn3 tz4 tsaa t 6 ® ��vun IMPERVIOUS = AREA=0.55 AC. (C=0.9) ° e PERVIOUS AREA=0.20 _ = _ ® Privatecnntrolstruotura AC. (C=0.25 SUB-BASIN#2 ; at ♦ Privata Discharge Point ) � ®® 0 Private water quality TOTAL AREA=1.86 AC. (C=0.35) t a PnvatenDetention Facilities ii 77 7709 7 � Ro e t7_ waua�a - t 1 t 1777 - Private Pipe � 71 t t � Private Culvert i Notes tso t t None 7z root t t a t z O to to t s = ats Information Technology - GIS This map is a user generated static output from an Internet mapping site and is for reference only. Data layers that appear on this map may or may not be City Of one 256 0 126 256 Feet RentonMapSupport@Rentonwa.gov accurate, current, or otherwise reliable. 11 WGS_1984_Web_Mercator_Auxiliary_Sphere 04/12/2017 THIS MAP IS NOT TO BE USED FOR NAVIGATION Finance 8c I.TDiViSiOn VI. Special Reports and Studies Special Reports related to this project: • Geotechnical Report. Nelson Geotechnical Assocaites, Inc., June 10, 2005 • Traffic Report. Jake Traffic Engineering, Inc., January 21, 2014 • NPDES Permit. Washington Department of Ecology 46 GEOTECHNICAL ENGINEERING EVALUATION GRANT'S PLACE RENTON, WASHINGTON PREPARED FOR TRIDOR, INC. NEL,SoN GEoTECHNICAL ASSOCIATES, INC. GEOTECHNIGAL ENGINEERS & GEOLOGISTS 17311--135'h Avenue NE, A-500 Woodinville, WA 98072 (425) 486-1669 . (425) Fax 481-2510 June 10, 2005 Mr. Scott Wiklof Tridor Inc. P.O. Box 747 Bellevue, WA 98009 Geotechnical Engineering Evaluation Grant's Place Renton, Washington NGA File No. 712005 Dear Mr. Wiklof: Snohomish County (425) 337-1669 Wenatchee/Chelan (509) 784-2756 We are pleased to submit the attached report titled "Geotechnical Engineering Evaluation — Grant's Place — Renton, Washington." This report summarizes the existing surface and subsurface conditions within the site and provides general recommendations for the proposed site development. Our services were completed in general accordance with the proposal signed by you on May 17, 2005. The site is currently occupied by a single-family residence and several outbuildings with brush and scattered trees within the western portion of the property. Development for this property is planned to consist of the construction of multiple three-story townhornes with associated pavement and utilities. Stormwater is to be managed on site via a detention system within the planned driveway access road. We monitored the excavation of eight test pits in the planned development areas. Our explorations indicated that the site is generally underlain by competent native glacial till deposits. The site is located in an area that was historically mined for coal. We did not observe evidence of mining operations such as mine shafts or tailings on this site. We also reviewed materials related to past coal mining activities in the site vicinity at the Washington State Department of Natural Resources. Based on our observations and the information we reviewed, it appears that mining operations were not specifically located on this site. We have concluded that the site is generally compatible with the planned development. We have recommended that the new structures be founded on the native medium dense or better soil for bearing capacity and settlement considerations. These soils should be encountered approximately one to two feet below the existing ground surface, based on our explorations. Minor to moderate amounts of groundwater were encountered within the upper soils in many of the test pits which may impact construction if earthwork activities take place during the wetter times of the year. Also, footing drains and other drainage systems should be incorporated into the design to control groundwater. In the attached report, we have also included general recommendations for site grading and drainage. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No. 712005 Summary - Page 2 It has been a pleasure to provide service to you on this project. Please contact us if you have any questions regarding this report or require further information. Sincerely, NELSON GEOTECHNICAL ASSOCIATES, INC. \aleMO.Sbawish, PE Principal Three Copies Submitted TABLE OF CONTENTS INTRODUCTION..................................................................................•................................................... I SCOPE...........................................................•............................................................................................. I SITECONDITIONS.................................................................................................................................. 2 SurfaceConditions.................................................................................................................................... 2 SubsurfaceConditions.............................................................................................................................. 2 HydrologicConditions.............................................................................................................................. 3 SENSITIVE AREA EVALUATION...................................................................................................•..... 3 SeismicHazard......................................................................................................................................... 3 ErosionHazard.......................................................................................................................................... 4 CONCLUSIONS AND RECOMMENDATIONS.........................................:......................................... 4 General................. ..... .......... ..... ... .............................................................................................................. 4 Erosion Control Measures..................................................................................................................... 5 Temporaryand Permanent Slopes............................................................................................................ 5 SitePreparation and Grading.................................................................................................................... 6 FoundationSupport .................................... ................................._............................................_........._..._.. 7 StructuralFill............................................................................................................................................ 8 Slab-on-Grade.................................................................................................................... .............. 9 Pavements............................................................................................................................ ....... 10 SiteDrainage........................................................................................................................................... 10 USEOF THIS REPORT.............................................................•............................................................11 LIST OF FIGURES Figure 1 — Vicinity Map Figure 2 — Site Plan Figure 3 — Soil Classification Chart Figures 4 and 5 — Test Pit Logs NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington INTRODUCTION This report presents the results of our geotechnical engineering investigation and evaluation of the planned Grant's Place development in Renton, Washington. The project site is located at 1600 Grant Avenue South as shown on the Vicinity Map in Figure 1_ The purpose of this study is to explore and characterize the site's surface and subsurface conditions and to provide geotechnical recommendations for site development. For our use in preparing this report, we have been provided with a site plan titled "Grant's Place," dated May 10, 2005, prepared by Kovach Architects. Development on the property will consist of the construction of 39 three-story, wood -framed townhome structures. A paved access driveway is planned for the middle of the property and will be accessed from Grant Avenue South on the western side of the property. Stormwater handling is planned to consist of an underground detention pipe or vault within the planned access road. The proposed site layout is shown on the Site Plan in Figure 2. SCOPE The purpose of this study is to explore and characterize the site surface and subsurface conditions, and provide general recommendations for site development. Specifically, our scope of services includes the following: 1. Review existing soils, geologic, and coal mine maps of the area. 2. Explore the site subsurface soil and groundwater conditions with trackhoe-excavated test pits. Trackhoe was subcontracted by NGA. 3. Provide recommendations for site grading and earthwork, including structural fill. 4. Provide recommendations for foundation support and slabs -on -grade subgrade. 5. Provide recommendations for stormwater infiltration or detention system installations as needed. 6. Provide recommendations for site drainage and erosion control. 7. Provide recommendations for pavement subgrade preparation. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No. 712005 Page 2 8. Document the results of our explorations, findings, conclusions, and recommendations in a written geotechnical engineering report. SITE CONDITIONS Surface Conditions The site is an approximate 2.1-acre, trapezoidal -shaped lot measuring approximately 621feet and 541 feet along the northern and southern property lines, respectively, and approximately 158 feet and 177 along the eastern and western property lines, respectively. The site is bounded to the east and south by residential properties, to the west by Grant Avenue South, and to the north by and undeveloped land. A single-family residence with a maintained grass lawn, scattered trees, and several outbuildings occupy the western portion of the property. The site is generally level with a slight gradient down to the west. An old shed, blackberry bushes, and scattered trees occupy the eastern half of the property. A small irrigation pond with a 3-foot high retaining wall was observed within the eastern half of the site approximately 100 feet east of the residence and 75 feet north of the southern property line. Except for some water in the irrigation pond, we did not observe surface water on site during our visit on May 23, 2005. Subsurface Conditions Geology: The geologic units for this site are shown on the Geologic Map of the Renton Quadranlg e, King County, Washin on, by D. R. Mullineaux, (U.S.G.S., 1965)_ The site is mapped as Ground Moraine Deposits (Qgt) which is further described as two types of till with varying densities. The till deposits are described as an unsorted mixture of sand, silt, clay, and gravel. Our explorations generally encountered silty sand consistent with the description of the ablation till of the Ground Moraine Deposit. Explorations: The subsurface conditions within the site were explored on May 23, 2005 by excavating eight test pits to depths ranging from 4.5 to 8.5 feet below the existing surface using a trackhoe. The approximate locations of our explorations are shown on the Site Plan in Figure 2. A geologist from NGA was present during the explorations, examined the soils and geologic conditions encountered, obtained samples of the different soil types, and maintained logs of the test pits. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No. 712005 Page 3 The soils were visually classified in general accordance with the Unwed Soil Classification System, presented in Figure 3. The logs of our test pits are attached to this report and are presented as Figures 4 and 5. We present a brief summary of the subsurface conditions in the following paragraph. For a detailed description of the subsurface conditions, the test pits logs should be reviewed.. We encountered approximately 0.5 to 1.5 feet of loose topsoil at the surface in all of the test pits. Below the topsoil, we encountered medium dense to dense, orangish-brown to grayish -brown, silty, fine to medium sand with gravel, iron -oxide staining, and sand lenses. This soil was interpreted as glacial till. All test pits were terminated in the till deposit. Minor to moderate caving was encountered in most of the test pits. Hydrologic Conditions Minor to moderate groundwater seepage was encountered within all of the explorations at depths ranging from 2.5 to 7.5 feet below the existing ground surface. It is our opinion that this seepage is perched water. Perched water occurs when surface water infiltrates through less dense, more permeable soils and accumulates on top of a relatively impermeable material such as the underlying silty sand. The more permeable soils consist of the topsoil and the upper weathered zone of the till. Perched water does not represent a regional groundwater "table" within the upper soil horizons. Perched water tends to vary spatially and is dependent upon the amount of rainfall. We would expect the amount of perched water to decrease during drier times of the year and increase during wetter periods. Due to the shallow occurrence of groundwater in our explorations and the relatively level ground surface, we anticipate that groundwater will be present on this site throughout the year. SENSITIVE AREA EVALUATION Seismic Hazard Medium dense to dense glacial soils were encountered underlying the site. Based on the 2003 International Building Code (IBC), the site conditions best fit the description for Soil Class D_ Hazards associated with seismic activity include liquefaction potential and amplification of ground motion by soft deposits. Liquefaction is caused by a rise in pore pressures in a loose, fine sand deposit beneath the groundwater table. Ground motion amplification is caused by thick deposits of soft material. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No. 712005 Page 4 The medium dense to dense glacial till interpreted to underlie the site has a low potential for liquefaction or amplification of ground motion. Erosion. Hazard The erosion hazard criteria used for determination of affected areas includes soil type, slope gradient, vegetation cover, and groundwater conditions. The erosion sensitivity is related to vegetative cover and the specific surface soil types, which are related to the underlying geologic soil units. The Soil Survey, King County Area, Washington, by the Soil Conservation Service (SCS) was reviewed to determine the erosion hazard of the on -site soils. The site surface soils were classified using the SCS classification system as Alderwood gravelly sandy loam, 6 to 15 percent slopes. This unit is listed as having a moderate erosion hazard. The site soils should have a low potential for erosion if not disturbed. CONCLUSIONS AND RECOMMENDATIONS General It is our opinion, that from a geotechnical standpoint, the site is compatible with the planned development. Our explorations within the site indicated that the site is generally underlain by competent glacial till soils. These native soils should provide adequate support for the planned structure foundations, slab -on -grade, and pavement. We recommend that the buildings be designed utilizing shallow foundations. Footings should extend through any loose surficial soil or undocumented fill and be founded on the underlying medium dense or better native soils, or structural fill extending to these soils. Undocumented fill or loose soil could be encountered around the existing house and out buildings. Any undocumented fill or soft/loose soil should be over -excavated as part of site preparation. Coal mining has been conducted in the past in the general site vicinity. We did not observe nine shafts, tailings, or other indications of mining operations on this site. Also, information collected at the Washington State Department of Natural Resources did not indicate that mining operations were specifically conducted on this site. We should note, however, that the reviewed DNR maps for coal mine shafts and tunnels are based on old records that may not be entirely accurate. The soils that are expected to be encountered during site development are considered highly moisture - sensitive and can disturb in wet conditions. Wet soil and seeping water was observed in our explorations NELSON GEOTECHIVICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No. 712005 Page 5 at shallow depths. We recommend that the site be developed during the dry season. If construction takes place during the rainy months, the site soils may disturb and become difficult to work. Also, if construction takes place during the wet season, additional expenses and delays should be expected. Additional expenses could include the need for placing a blanket of rock spalls on exposed subgrades, construction traffic areas, and pavement areas prior to placing structural fill. NGA should be retained to determine if the on -site soils could be used as structural fill material during construction. We anticipate that wet conditions will be prevalent on this site throughout the year. We recommend that footing and wall drains as well as underslab drains be incorporated in the design. Also, cut-off or French - type drains might be needed at certain locations to maintain dry conditions. Erosion Control Measures The erosion hazard for the on -site soils is considered moderate, but will be dependent on how the site is graded -and how water is allowed to concentrate. Best Management Practices (BMPs) should be used to control erosion. Areas disturbed during construction should be protected from erosion. Measures taken may include diverting surface water away from the stripped areas. Silt fences or straw bales should be erected to prevent muddy water from leaving the site. Temporary and Permanent Slopes We do not anticipate major grading on this site as part of site improvements, however, if an underground stormwater detention vault or a large detention pipe is used for handling stormwater runoff, temporary cuts over four feet in height may be needed for the installation of these systems. Temporary cut slope stability is a function of many factors, including the type and consistency of soils, depth of the cut, surcharge loads adjacent to the excavation, length of time a cut remains open and the presence of surface or groundwater. It is exceedingly difficult under these variable conditions to estimate a stable, temporary, cut slope angle. Therefore, it should be the responsibility of the contractor to maintain safe slope configurations since he is continuously at the job site, able to observe the nature and condition of the cut slopes, and able to monitor the subsurface materials and groundwater conditions encountered. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No: 712005 Page 6 The following information is provided solely for the benefit of the owner and other design consultants and should not be construed to imply that Nelson Geotechnical Associates, Inc. assumes responsibility for job site safety. Job site safety is the sole responsibility of the project contractor. For planning purposes, we recommend that temporary cuts in the native glacial till soils be no steeper than 1.5 Horizontal to 1 Vertical (1.5H:IV). If significant groundwater seepage or sandier portions of the till are encountered, we would expect that flatter inclinations would be necessary. We recommend that cut slopes be protected from erosion. Measures taken may include covering cut slopes with plastic sheeting and diverting surface runoff away from the top of cut slopes. We do not recommend vertical slopes for cuts deeper than four feet, if worker access is necessary. We recommend that cut slope heights and inclinations conform to appropriate OSHA/WISHA regulations. Site Preparation and Grading After the existing residence, trees, and ground cover have been removed, the next step of site preparation should be to strip any topsoil or loose material to expose medium dense or better native soils in foundation, pavement, and slab areas. Based on our observations, we anticipate an average stripping depth of the topsoil to be one to two feet across the site. However, additional stripping may be required in the vicinity of the existing residence and outbuildings, the pond, or in the unexplored areas where fill may exist. If the ground surface, after stripping the unsuitable material and excavating down to planned subgrade elevations appears to be loose, it should be compacted to a non -yielding condition and then proof -rolled with a heavy rubber -tired piece of equipment. Areas observed to pump or weave during the proof -roll test should be reworked to structural fill specifications or over -excavated and replaced with properly compacted structural fill or rock spalls. If significant surface water flow is encountered during construction, this flow should be diverted around areas to be developed and the exposed subgrade maintained in a semi -dry condition. After the water has been controlled, the site should be stripped and graded using large excavators equipped with wide tracks and smooth buckets. The exposed subgrade should not be compacted, as compaction of a wet subgrade may result in further disturbance of the native soils. Instead, a layer of crushed rock or all-weather material may be placed over the prepared areas to protect them from further disturbance. NELSON OEOTECHNICAL ASSOCIATES, INC Geotechnical Engineering Evaluation Grant's place Renton, Washington June 10, 2005 NGA File No. 712005 Page 7 If a detention system is used, it should be excavated down to planned elevations while maintaining the recommended temporary excavation inclinations provided above. if groundwater seepage is encountered, this water should be pumped out of the excavation and the bottom of the excavation be covered with a minimum of six inches of crushed rock to reduce the potential for disturbing the sensitive subgrade and to provide a clean work surface for vault or pipe placement. As mentioned earlier, the site soils are considered highly moisture sensitive and can disturb when wet. We therefore recommend that construction take place in the summer during periods of extended dry weather, and suspended during periods of rainfall. If work is to take place during the wetter part of the year, care should be taken during site preparation not to disturb the site soils. This can be accomplished by utilizing large excavators equipped with smooth buckets and wide tracks to complete earthwork, and diverting surface and groundwater flow away from the prepared subgrades. Also, construction traffic should not be allowed on the exposed subgrade. A blanket of rock spalls should be used in construction access areas if wet conditions are prevalent. The thickness of this rock spall layer should be based on subgrade performance at the time of construction. For planning purposes, we recommend a minimum one -foot thick layer of rock spalls. Foundation Support Conventional shallow spread foundations for building support should be placed on undisturbed medium dense or better native soils or be supported on structural fill or rock spalls extending to those soils. Where less dense soils are encountered at footing bearing elevation, the subgrade should be over -excavated to expose suitable bearing soil. The over -excavation may be filled with structural fill, or the footing may be extended down to the bearing native soils. If footings are supported on structural fill, the fill zone should extend outside the edges of the footing a distance equal to one-half of the depth of the over -excavation below the bottom of the footing. Building footings should extend at least 18 inches below the lowest adjacent finished ground surface for frost protection and bearing capacity considerations. Minimum foundation widths of 18 and 24 inches should be used for continuous and isolated footings, respectively, but footings should also be sized based on the anticipated loads and allowable soil bearing pressure. Standing water should not be allowed to NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant' s Place Renton, Washington June 10, 2005 NGA File No. 712005 Page 8 accumulate in footing trenches. All loose or disturbed soil should be removed from the foundation excavation prior to placing concrete. For foundations constructed as outlined above, we recommend an allowable design bearing pressure of not more than 2,000 pounds per square foot (psf) be used for the building footing design for footings founded on the medium dense or better native soils or structural fill extending to the native competent material. The foundation bearing soil should be evaluated by a representative of NGA. We should be consulted if higher bearing pressures are needed. Current IBC guidelines should be used when considering increased allowable bearing pressure for short-term transitory wind or seismic loads. Potential foundation settlement using the recommended allowable bearing pressure is estimated to be less than one inch total and 1/2 inch differential between adjacent footings or across a distance of about 20 feet. Lateral loads may be resisted by friction on the base of the footing and passive resistance against the subsurface portions of the foundation. A coefficient of friction of 0.35 may be used to calculate the base friction and should be applied to the vertical dead load only. Passive resistance may be calculated as a triangular equivalent fluid pressure distribution. An equivalent fluid density of 250 pounds per cubic foot (pcf) should be used for passive resistance design for a level ground surface adjacent to the footing. This level surface should extend a distance equal to at least three times the footing depth. These recommended values incorporate safety factors of 1.5 and 2.0 applied to the estimated ultimate values for frictional and passive resistance, respectively. To achieve this value of passive resistance, the foundations should be poured "neat" against the native medium dense to dense soils or compacted fill should be used as backfill against the front of the footing. We recommend that the upper one -foot of soil be neglected when calculating the passive resistance. Structural Fill General. Fill placed beneath foundations, pavement, or other settlement -sensitive structures should be placed as structural fill. Structural fill, by definition, is placed in accordance with prescribed methods and standards, and is monitored by an experienced geotechnical professional or soils technician. Field monitoring procedures would include the performance of a representative number of in -place density tests to document the attainment of the desired degree of relative compaction. The area to receive the fill NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No. 712005 Page 9 should be suitably prepared as described in the Site Preparation and Grading subsection prior to beginning fill placement. Materials: Structural fill should consist of a good quality, granular soil, free of organics and other deleterious material and be well graded to a maximum size of about three inches. All-weather fill should contain no more than five -percent fines (soil finer than U.S. No. 200 sieve, based on that fraction passing the U.S. 314-inch sieve). The use of on -site soils as structural fill should generally be feasible, but will be dependent on material moisture content at the time construction takes place. Most of the on -site soils will be very difficult to compact to structural fill specifications in wet conditions. Even in dry weather, some moisture -conditioning of the on -site material night be required to attain compactable conditions. We should be retained to evaluate proposed structural fill material prior to construction. Fill Placement: Following subgrade preparation, placement of structural fill may proceed. All filling should be accomplished in uniform lifts up to eight inches thick. Each lift should be spread evenly and be thoroughly compacted prior to placement of subsequent lifts. All structural fill underlying building areas and pavement subgrade should be compacted to a minimum of 95 percent of its maximum dry density. Maximum dry density, in this report, refers to that density as determined by the ASTM D-1557 Compaction Test procedure. The moisture content of the soils to be compacted should be within about two percent of optimum so that a readily compactable condition exists. It may be necessary to over - excavate and remove wet soils in cases where drying to a compactable condition is not feasible. All compaction should be accomplished by equipment of a type and size sufficient to attain the desired degree of compaction. Slab -on -Grade Slabs -on -grade should be supported on subgrade soils prepared as described in the Site Preparation and Grading subsection of this report. We recommend that all floor slabs be underlain by at least six inches of free -draining sand or gravel for use as a capillary break. We recommend that the capillary break be hydraulically connected to the footing drain system to allow free drainage from under the slab. A suitable vapor barrier, such as heavy plastic sheeting (6-mil minimum), should be placed over the capillary break material. Due to the wet site conditions, it might be prudent to utilize a system of underllab drains that are in turn routed to the perimeter drains, to further reduce the potential for groundwater to produce damp conditions in the dwellings. NELSON GE'OTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No. 712005 Page 10 Pavements Pavement subgrade preparation, and structural filling where required, should be completed as recommended in the Site Preparation and Grading and Structural Fill subsections of this report. The pavement subgrade should be proof -rolled with a heavy, rubber -tired piece of equipment, to identify soft or yielding areas that require repair. We should be retained to observe the proof -rolling and recommend repairs prior to placement of the asphalt or hard surfaces. Site Drainage Surface Drainage: The finished ground surface should be graded such that stormwater is directed to an appropriate stormwater collection system. Water should not be allowed to stand in any area where footings or slabs are to be constructed. Final site grades should allow for drainage away from the structures. We suggest that the finished ground be sloped at a minimum gradient of three percent, for a distance of at least 10 feet away from the structures. Surface water should be collected by permanent catch basins and drain lines, and be discharged into an appropriate discharge system. Subsurface Drainage: If groundwater is encountered during construction, we recommend that the contractor slope the bottom of the excavation and collect the water into ditches and small sump pits where the water can be pumped out of the excavation and routed into a permanent storm drain. We recommend the use of footing drains around the planned structure. Footing drains should be installed at least one foot below planned finished floor elevation. The drains should consist of a minimum four - inch -diameter, rigid, slotted or perforated, PVC pipe surrounded by free -draining material, such as washed rock, wrapped in a filter fabric. We recommend that an 18-inch-wide zone of clean (less than three -percent fines), granular material be placed along the back of the walls above the drain. Pea gravel is an acceptable drain material or drainage composite may also be used instead. The free -draining material should extend up the wall to one foot below the finished surface. The top foot of backfill should consist of impermeable soil placed over plastic sheeting or building paper to minimize surface water or fines migration into the footing drain. Footing drains should discharge into tightlines leading to an appropriate collection and discharge point with convenient cleanouts to prolong the useful life of the drains. Roof drains should not be connected to footing drains. NELSON GEOTECHNIeAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No, 712005 Page 11 Due to prevalent wet site conditions, cut -of or French -type drains may be required uphill of the planned improvements to control groundwater and maintain semi -dry pads. The need and extent of such systems should be determined in the field prior to the start of mass grading. Also, underslab drains might be considered for this site. The underslab drain systems usually consist of 4-inch perforated lateral pipes placed within the capillary break layer, 10 to 15 feet apart. The laterals are routed to a solid main collector drain that in turn is routed into the footing drain system. We should be retained to review plans for site drainage. USE OF THIS REPORT NGA has prepared this report for Tridor Inc., and their agents, for use in the planning and design of the development planned on this site only. The scope of our work does not include services related to construction safety precautions and our recommendations are not intended to direct the contractors' methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. There are possible variations in subsurface conditions between the explorations and also with time. Our report, conclusions, and interpretations should not be construed as a warranty of subsurface conditions. A contingency for unanticipated conditions should be included in the budget and schedule. We recommend that NGA be retained to provide monitoring and consultation services during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork and foundation installation activities comply with contract plans and specifications. We should be contacted a minimum of one week prior to construction activities and could attend pre -construction meetings if requested. Within the limitations of scope, schedule, and budget, our services have been performed in accordance with generally accepted geotechnical engineering practices in effect in this area at the time this report was prepared. No other warranty, expressed or implied, is made. Our observations, findings, and opinions are a, means to identify and reduce the inherent risks to the owner. • i • NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Grant's Place Renton, Washington June 10, 2005 NGA File No. 712005 Page 12 It has been a pleasure to provide service to you on this project. If you have any questions or require further information, please call. Sincerely, NELSON GEOTECHNICAL ASSOCIATES, INC. ;�Bala Dodoye-Alalz Project Geologist e EXPIRES. J)<- Khaled M. Shawish, PE Principal Five Figures Attached NELSON GEOTECHNICAL ASSOCIATES, INC. NOT TO SCALE Project Number 712005 Figure 1 NELsoN GEOrecHNICAL Grants Place �j(A AsSOCIATEs� INC. GEOTECHNICAL ENGINEERS & GEOLOGISTS Vicinity Map 1781'1_195hA— NE. Ad50 sno 11"I Cw,ay((azs ssr-2756 Woo&Mm, WANM Wenetcfiaa�p.* (so9j)7sa-27ss (4Z)481 -4665l Fex4fH-2576 _..bongao9etlsaxn Nod Date I Revision 1 i 51241W i Original By ICK --T- ACO(3AD \ 10 20 Reference: Site Plan based on an electronic plan dated May 25, 2005, titled "Grant's Place," prepared by Kovach Architects. UNIFIED SOIL CLASSIFICATION SYSTEM GROUP MAJOR DIVISIONS GROUP NAME SYMBOL CLEAN GW WELL -GRADED, FINE TO COARSE GRAVEL COARSE- GRAVEL GRAVEL GP POORLY -GRADED GRAVEL GRAINED MORE THAN 50 % GRAVEL GM SILTY GRAVEL OF COARSE FRACTION RETAINED ON SOILS NO.4 SIEVE WITH FINES GC CLAYEY GRAVEL SAND CLEAN SW WELL -GRADED SAND, FINE TO COARSE SAND SAND SP POORLY GRADED SAND MORE THAN 50 % RETAINED ON MORE THAN 50 % NO. 200 SIEVE OF COARSE FRACTION SAND�'(� SILTY SAND PASSES NO.4 SIEVE SC WITH FINES CLAYEY SAND FINE - SILT AND CLAY ML SILT INORGANIC GRAINED LIQUID LIMIT CL CLAY LESS THAN 50 % SOILS ORGANIC OL ORGANIC SILT, ORGANIC CLAY SILT AND CLAY MH SILT OF HIGH PLASTICITY, ELASTIC SILT INORGANIC MORE THAN 50 % PASSES LIQUID LIMIT CH CLAY OF HIGH PLASTICITY, FLAT CLAY NO.200 SIEVE 50 % OR MORE ORGANIC OH ORGANIC CLAY, ORGANIC SILT HIGHLY ORGANIC SOILS PT PEAT NOTES: 1) Field classification is based on visual SOIL MOISTURE MODIFIERS: examination of soil in general accordance with ASTM D 2488-03. Dry - Absence of moisture, dusty, dry to the touch 2) Sol[ classification using laboratory tests is based on ASTM D 24W93. Moist - Damp, but no visible water. ci N 3) Descriptions of soil density or Wet -Visible free water or saturated, o consistency are based on usually soil is obtained from ti interpretation of blowcount data, below water table visual appearance of soils, and/or test data. o 0 N Project Number \ NIELSON GIEOT14Ct Nir-AL No. Date I7evision By CK 712005 Grarlt�S Place �` 1,,, N A ASSOCIATES, INC. 9 W4M Original ACO N BAD Sail Classification G+. EOTECHiNICAL ENG:INEERS & GEOLQGIs rs . g � Figure 3 17311-1359,A..NE. ASOD woodrrAK WASW72 en�,�,C�t,�,3V-1W9 Wenatcheek7heten ( r6aa755 o ¢ (445)4WM660/Fax45i-4610 www.nateo= U' LOG OF EXPLORATION DEPTH (FEET) USC SOIL DESCRIPTION TEST PIT ONE 0.0 -1.0 TOPSOIL (LOOSE, MOIST) 1.0 - 2.5 SM ORANGISH-BROWN TO BROWN, SILTY FINE TO COARSE SAND (MEDIUM DENSE, MOIST) 2.5-7.0 SM ORANGISH-BROWN TO BROWN, SILTY FINE TO COARSE SAND WITH GRAVEL AND COBBLES (DENSE, MOIST) 7.0-8.5 SP-SM GRAY, FINE TO MEDIUM SAND WITH SILT ANDGRAVEL (DENSE, WET) SAMPLE WAS COLLECTED AT 4.5 FEET MINOR GROUNDWATER SEEPAGE WAS ENCOUNTERED AT 7.5 FEET MINOR TEST PIT CAVING WAS ENCOUNTERED FROM 7.0 TO 8.5 FEET TEST PIT WAS COMPLETED AT 8.5 FEET ON 5123/05 TEST PIT TWO 0.0- 0.5 TOPSOIL WITH ROOTS (LOOSE, MOIST) 0.5 -2.0 SM ORANGISH-BROWN, SILTY FINE TO MEDIUM SAND WITH GRAVEL (MEDIUM DENSE, MOIST) 2.0 - 7.0 SM GRAY, SILTY FINE TO COARSE SAND WITH GRAVEL (DENSE TO VERY DENSE, MOIST) SAMPLE WAS COLLECTED AT 3.2 FEET MODERATE GROUNDWATER SEEPAGE WAS ENCOUNTERED AT 6.5 FEET TEST PIT CAVING WAS NOT ENCOUNTERED TEST PIT WAS COMPLETED AT 7.0 FEET ON 5/23/05 TEST PIT THREE 0.0 -1.0 TOPSOIL (LOOSE, MOIST) 1.0-2.5 SM ORANGISH-BROWN, SILTY FINE TO MEDIUM SAND (MEDIUM DENSE, MOISTTO WET) 2.5 - 7.0 SM GRAYISH -BROWN, SILTY FINE TO MEDIUM SAND (DENSE, MOIST TO WET) SAMPLE WAS COLLECTED AT 2.0 FEET MINOR TO MODERATE GROUNDWATER SEEPAGE WAS ENCOUNTERED AT 3.0 FEET MINOR TEST PIT CAVING WAS ENCOUNTERED FROM 6.0 TO 7.5 FEET TEST PIT WAS COMPLETED AT 7.0 FEET ON 5/23105 TEST PIT FOUR 0.0 -1.0 TOPSOIL (LOOSE, MOIST) 1.0 - 2.5 SM ORANGE, SILTY FINE TO MEDIUM SAND WITH GRAVEL (LOOSE TO MEDIUM DENSE, MOIST TO WET) 2.5-4.5 SM ORANGISH-BROWN, SILTY FINE TO COARSE SAND WITH GRAVEL (DENSE, MOIST) SAMPLES WERE NOT COLLECTED MINOR TO MODERATE GROUNDWATER SEEPAGE WAS ENCOUNTERED AT 2.5 FEET TEST PIT CAVING WAS NOT ENCOUNTERED TEST PIT WAS COMPLETED AT 4.5 FEET ON 5/23/05 ACO:BAD NELSON GEOTECHNICAL ASSOCIATES, INC. FILE NO 712005 FIGURE 4 LOG OF EXPLORATION DEPTH (FEET) TEST PIT FIVE 0.0 - 1.2 1.2 - 5.0 5.0-6.0 TEST PIT SIX 0.0 -1.0 1.0 - 3.0 3.0-5.0 TEST PIT SEVEN 0.0 - 1.0 1.0 - 2.5 2.5-6.5 TEST PIT EIGHT 0.0 - 1.5 1.5 - 6.0 ACO: BAD USC SOIL DESCRIPTION TOPSOIL (LOOSE, MOIST) SM ORANGISH-BROWN, SILTY FINE TO MEDIUM SAND WITH GRAVEL (MEDIUM DENSE, MOIST TO WET) SM ORANGISH-BROWN, SILTY FINE TO MEDIUM SAND WITH SILT LAYERS AND IRON -OXIDE STAINING (DENSE, MOIST) SAMPLES WERE COLLECTED AT 3.0 ND 6.0 FEET MINOR TO MODERATE GROUNDWATER SEEPAGE WAS ENCOUNTERED FROM 2.5 TO 6.0 FEET MINOR TEST PIT CAVING WAS ENCOUNTERED FROM 0.0 TO 6.0 FEET TEST PIT WAS COMPLETED AT 6.0 FEET ON 5/23/05 TOPSOIL (LOOSE, MOIST) SM ORANGISH-BROWN, SLTY FINE TO MEDIUM SAND WITH GRAVEL (MEDIUM DENSE, MOIST) SM ORANGISH-BROWN, SILTY FINE TO MEDIUM SAND WITH IRON -OXIDE STAINING (MEDIUM DENSE, MOIST TO WET) SAMPLES WERE NOT COLLECTED MODERATE GROUNDWATER SEEPAGE WAS ENCOUNTERED AT 3.0 FEET MINOR TEST PIT CAVING WAS ENCOUNTERED FROM 4.0 TO 5.0 FEET TEST PIT WAS COMPLETED AT 5.0 FEET ON 5/23/05 TOPSOIL (LOOSE, MOIST) SM ORANGE, SILTY FINE TO MEDIUM SAND WITH ROOTS (MEDIUM DENSE, MOIST) SM ORANGISH-BROWN, SILTY FINE TO MEDIUM SAND WITH GRAVEL AND IRON -OXIDE STAINING (MEDIUM DENSE TO DENSE, MOIST) SAMPLE WAS COLLECTED AT 4.0 FEET MINOR GROUNDWATER SEEPAGE WAS ENCOUNTERED FROM 2.0 TO 6.5 FEET MINOR TEST PIT CAVING WAS ENCOUNTERED FROM 2.5 TO 6.5 FEET TEST PIT WAS COMPLETED AT 6.5 FEET ON 5/23/05 TOPSOIL WITH ROOTS (LOOSE, MOIST) SM ORANGISH-BROWN, SILTY FINE TO MEDIUM SAND WITH SILT LAYERS AND IRON -OXIDE STAINING (MEDIUM DENSE, MOIST TO WET) SAMPLES WERE COLLECTED AT 2.0 AND 6.0 FEET MINOR GROUNDWATER SEEPAGE WAS ENCOUNTERED AT 4.5 FEET MINOR TEST PIT CAVING WAS ENCOUNTERED FROM 4.5 TO 5.0 FEET TEST PIT WAS COMPLETED AT 6.0 FEET ON 5/23/05 NELSON GEOTECHNICAL ASSOCIATES, INC. FILE NO 712005 FIGURE 5 Renton GRANT PLACE TOWNHOMES SITE ACCESSITRAFFIC IMPACT FEE TRAFFIC LETTER January 21, 2014 JTE .Jake Traffic Engineering, Inc. Mark J. Jacobs, PE, PTOE, President 2614 39�" Ave SW -Seattle, WA 98116 - 2503 Tel. 206.762.1978 -Cell 206.799.5692 E-mail iaketraffic@comcast.net JTE.Jake Traffic Engineering Inc . GRANT PLACE TOWNHOMES Attn: Michael Chan 316 Maynard Ave. S. #101-105 Seattle WA 98104 Re: Grant Place Townhomes -Renton Si[e Access/Traffic Impact Fee Traffic Letter Mark J. Jacobs, PE, PTOE President 2614 39�^ Ave. SW -Seattle, WA 981 I d - 2503 iel. 206.162.1978 -Cell 206.799.5692 E-maB jakemRm�wnitasLcet January 21, 2014 Dear Mr. Chan, I am pleased to submit this Site Access/Traffic Impact Fee Traffic Letter for the proposed 36 units Grant Place Townhomes project located at 1600 Grant Avenue South on parcel #2023059052 in the City of Renton. Access to the site is provided via separate ingress and egress only driveways on Grant Avenue South. Prior to this report I prepared Gmnt Place Townhomes Site Access/Traffic Impact Fee Analysis dated November 25, 2006. The Grant Place Townhomes project did not come to fruition. Germaine data from my prior research on the site is incorporated into this letter. I have reviewed the site and surrounding street system. The study scope was determined pursuant with prior correspondence with the City of Renton, my prior work on the site and review of the City's TIA Guidelines for new developments. The City peak hour trip threshold is 20 net new trips. The general format of this report is to describe the proposed project, calculate the traffic that would be generated by the project, review the site accesses and ascertain the Traffic Impact Fee for the project The summary and conclusions are on page six of this report. PROJECT INFORMATION An aerial image of the site obtained from King County IMap is to the right: Figure 1 is a vicinity map showing the location of the proposed site and surrounding street network. Figure 2 shows a preliminary site plan prepared by Milbrandt Architects November 20, 2013. JTE, Inc. GRANT PLACE TOWNHOMES Attn: Michael Chan January 21, 2014 Page -2- The plan consists of the project layout comprising of 36 townhome units to be built housed in 8 buildings. Internal circulation is also shown. Access to the site Is provided via an entry only and an exit only driveway on Grant Avenue South. Full development and occupancy of the proposed Grant Place Townhomes project Is anticipated to occur by 2015/16, presuming the permits are issued in a timely manner. EXISTING ENVIRONMENT Project Site The project site Is located on parcel #2023059052 and is presently developetl with one existing single family tlwelling unit. This existing housing unit would be removed to make way for the subject project. Additional Information on this parcel is attached in [he appendix. Street Svstem Figure 3 shows the existing traffic control, number of street lanes, number of approach lanes at the intersections and other pertinent information. The primary streets within the study area and their classifications per the City of Renton Comprehensive Plan are as follows: Y S. Puget Dr. Minor Collector ➢ Grant Avenue South Unclassified D S. 18�^ St. Unclassified Grant Avenue South is a two lane street with a posted speed limit of 25 MPH. An advisory curve warning speed of 20 MPH is identified for the horizontal street curvature in the vicinity of the project site. Traffic Volumes The City of Renton Traffic Flow Mao, 2010 indicates the 2010 daily traffic on Grant Ave. S. at 2,000 to 2,500 vpd in the site vicinity. Pedestrian Facilities Curb, gutter and sitlewalk exist on both sides of 108�^ Ave. SE (SR - 515). drools Renton School District identified students living in the Grant Place Townhomes woultl attend the following schools: ➢ Talbot Hill Elementary School - 2300 Talbot Road S, Renton, WA 98055 ➢ Dimmit Middle School - 12320 80th Avenue S, Seattle, WA 98178 ➢ Renton High School - 400 S 2nd St, Renton, WA 98057 Students attending the above schools would be eligible for bus transportation. JTE, Inc. GRANT PLACE TOWNHOMES Attn: Michael Chan January 21, 2014 Page -3- Accident History WSDOT electronically provided 3 years 11 months (January 1, 2010 to November 31, 2013) of accident data for Grant Avenue S. from S. Puget Drive to Beacon Way South. I have reviewed the data; the data indicates 3 recorded incidents (inattention, improper backing and under the influence) on Grant Ave. S. between S. Puget Drive and Beacon Avenue South. STREET IMPROVEMENT PROJECTS The City of Renton 6 vear Transportation Improvement Proeram, 2013 to 2018 was reviewed. No TIP project is noted on Grant Avenue South. I have included the project map index in the Appendix of this letter. The 6 year TIP is available on the City's web site. TRIP GENERATION AND DISTRIBUTION Definitions A vehicle trip is defined as a single or one direction vehicle movement with either the origin or destination (existing or entering) inside the proposed development. Traffic generated by development projects consists of the following types: Pass -By Trips: Trips made as intermediate stops on the way from an origin to a primary trip destination. Diverted Link Trips: Trips attracted from the traffic volume on roadways within the vicinity of the generator but require a diversion from that roadway to another roadway to gain access to the site. Captured Trips: Site trips shared by more than one land use in a multi -use development. Primary (New) Trips: Trips made for the specific purpose of using the services of the project. Trio Generation The proposed Grant Place Townhomes project is expected to generate the vehicular trips during the average weekday, street traffic AM and PM peak hours as shown in Table 1. The trip generation for the project is calculated using trip rates from the Institute of Transportation Engineers (ITE) Trio Generation, 9N Edition, for Single Family Detached Housing and Residential Condominium/Townhouse (ITE land Use Code 210 and 230, respectively). All site trips made by all vehicles for all purposes, including commuter, visitor, and service and delivery vehicle trips are included in the trip generation values. Residential Condominium/Townhomes generate predominantly primary trips. There would be some captured/pass-by trips that alreatly exist within the vicinity; such as mail delivery, garbage, and other service/delivery traffic. One existing single family dwelling unit exist on JTE, Inc. GRANT PLACE TOWNHOMES Attn: Michael Chan January 21, 2014 Page -4- the site. Credits towards this single family dwelling unit were taken from the proposed Grant Place Townhomes. Based on our analysis, the trips generated by the Grant Place Townhomes project are calculated to be 199 net new daily and 18 net new trips during the PM peak hour. SITE ACCESS SIGHT DISTANCE I field inspected, using a measuring wheel, the available stopping sight distance (SSD) and entering sight distance (ESD) at the proposed site access. The north site access is to be Ingress only and the south access egress only. The SSD was measured to a 2 ft. high object "vehicle tail light" standards. The 2 ft. object height is per the American Association of State Highway and Transportation Officials (AASHTO). Prior correspondence with the City of Renton Identified that they use the American Association of State Highway and Transportation Officials (AASHTO) criteria for sight distance. The results of the field measurements are summarized in Table 2. Table 2 shows the stopping and entering sightdlstance standards per the identified MPH at the proposed Ingress and egress driveways. The stopping and entering sight distance were obtained from the American Association of State Highway and Transportation Officials (AASHTO) A Policv on Geometric Design of Hi2hways an Streets, 2001 Fourth Edition "Exhibit 9-55. Design Intersection Sight Distance -Case B1 -Left Turn from stop' (attached in the appendix). Grant Avenue Scuth has a posted 25 MPH speed limit. An advisory speed sign of 20 MPH is also identifietl along the bend on Grant Avenue S. in the vicinity of the proposed project. Table 2 itlentifies the stopping and entering sight distance for the posted (25 MPH) speed limi[and the advisory (20 MPH) speed. Below are pictures at the proposed site accesses; ingress only and egress only. North Site Driveway (Ingress Only) JTE, Inc. GRANT PLACE TOWNHOMES Attn: Michael Chan January 21, 2014 Page -5- The critical AASHTO criterion is Stopping Sight Distance for the ingress only driveway. Motorists need to have sufficient sight lines to see vehicles turning into the site. Ample SSD is available at the proposed Ingress only driveway. Appropriate "Enter Only" signage neetls to installed at the ingress only driveway. And conversely signage that states "NO EXIT ALLOWED" needs to be installed. South Site Driveway (Egress Only) The above photographs were taken from the existing driveway about 15' north of the proposed driveway. The new driveway location would remove the existing Cedar Tree seen in the photograph looking south. The egress only driveway provides the more critical SSD that exceeds the criterion fora 25 MPH speed. Egress motorists have sufficient ESD based on the advisory speed of 20 MPH. Parked vehicles affect sight lines. No parking should be allowed in the near vicinity of the proposed egress driveway. A 30 feet "No Parking" zone to the north and south of the proposed egress driveway is recommended. The 30' dimension Is consistent with field data I have observed over the years. Additionally, signage at the egress driveway needs to identify that the driveway is "Exit Only". Summary: Based on my analysis the proposed ingress only on Grant Avenue South meets the AASHTO stopping sight distance criteria. At the egress driveway the more critical SSD is met for the posted speed limit of 25 MPH and ESD criterion is met for the advisory speed of 20 MPH. Pruning/removinguegetation looking to/from the north to greater enhance sight visibility is recommended. Pruning/removingthe vegetation in the right-of-way would increase the entering sight distance to/from the north by -25 feet. JTE, Inc. GRANT PLACE TOWNHOMES Attn: Michael Chan January 21, 2014 Page -& AGENCY TRAFFIC IMPACT MITIGATION REQUIREMENTS The City of Renton has a Traffic Impact Fee program per Ordinance #5670 effective January 1, 2013. The TIF is scheduled to be phased in over time. The Pre-aonlication Meetine Notes identify the 2014 TIF at $$789.44 per TH; and a TIF of $1,430.72 per SFDU. A TIF of $26,989.12 ($28,419.84 (36 - TH's) - $1,430.72 (1-Existing SFDU to be removed)) is thus tletermined. This fee adjusts annually and is scheduled to go up in 2015. Access improvements per City requirements will be required. Construct the internal street in conformance to City requirements. SUMMARY AND CONCLUSION This letter was prepared to identify the Trip Generation of the proposed project, review the Site Access Sight Lines and calculate the City's Traffic Impact Fee. Based on my analysis the proposed Grant Place Townhomes project is expected to generete 199 net new daily and 18 net new PM peak hour trips. The City trip threshold is 20 ......... no City classified intersection would be effected by site traffic. The proposed site ingress with Grant Avenue South meets the AASHTO sight distance criteria fora 25 MPH speed Ilmit. The egress driveway meets the critical SSD and the AASHTO entering sight distance criteria for the advisory speed of 20 MPH. A traffic impact fee of $26,989.12 is calculated [o be contributed to the City of Renton's traffic impact fee program. Based on my analysis I recommend that Grant Place Townhomes be allowed with the followingtraffic impact mitigation measures. D Construct site in accordance with applicable City requirements. ➢ Conduct a survey to verify the site access sight lines prior to Preliminary Plat Approval. ➢ Provide an appropriate vegetation clearing removal in the ROW. ➢ A 30 feet "No Parking" zone to the north and south of the proposed egress driveway. 1 Install appropriate "Enter Only" and "NO EXIT ALLOWED" at the ingress driveway and "Exit Only" signage at the egress driveway. ➢ Pay lawful traffic impact mitigation fee. Please contact me at 206.762.1978 or email me at iaketraffic�comcast.net if you have any questions. Sincerely, Mark J. Jacobs, PE, PTOE, President IAKE TRAFFIC ENGINEERING, INC JTE, Inc. VEHICULAR TRIP GENERATION TABLE 1 GRANT PLACE TOWNHOMES - RENTON SITE ACCESS/TRAFFIClMPACT FEE TRAFFIC LETTER TIME PERIOD TRIP RATE TRIPS ENTERING TRIPS EXITING TOTAL Single Family Deta hed ousing (ITE Land Use Cotle 210, one lot) -Existing Average Weekday T= 9.52X 5 (50%) 5 (50%) 10 AM Peak Hour T = 0.75X 0 (25%) 1(75%) 1 PM peak Hour T = 1.00X 1(63%) 0 (37%) 1 Residential Contlo iniu ownhouse (ITE Land Use Cotle 230, 36 units) -Proposed Averege Weekday T = 5.81X 105 (50%) 104 (50%) 209 AM Peak Hour T = 0.44X 3 (17%) 13 (83%) i6 PM peak Hour T = 0.52X 13 (67%) 6 (33%) 19 Total (Proposed - isti g) Average Weekday 100 99 199 AM Peak Hour 3 12 15 PM peak Hour - 12 6 16 T =trips X = number of ots lots A vehicle trip i def ned as a single or one direction vehicle movement with either the origin or destination exis ing or entering) inside the study site. The above trip en ration values account for all the site trips made by all vehicles for all purposes, incl din commuter, visitor, recreation, and service and delivery vehicle trips JTE, Inc. SIGHT DISTANCE SUMMARY TABLE 2 GRANT PLACE TOWNHOMES - RENTON SITE ACCESS/TRAFFIC IMPACT FEE TRAFFIC LETTER AASHTO Criteria Looking Looking (MPH) Grant Ave ue South to/from the to/from the north south Advisory Posted 20 MPH 25 MPH North Site Access (Ingress Only) Stopping Sigh}Distance (ft.) -180' -280' 115' 155' Not Applicable - - 225' 280' South Site Access (Egress Only) Stopping Sight Distance (tt.) -230' -165' 115' 155' Entering Sight Distance (ft.) -210'; _235'� ' 225' 280' � -235'i i - Pruning removing the vegetation in the right-of-way would increase the entering sight distance to/from the north by -25 feet � -Sight line with existing Cetlar Tree removed Project: Grant Place Townhomes -Renton Location: 1fi00 Grant Avenue South NORTIi -_ ni. ,, € a � � � � � {� a z r s � � z a � � � se r t "` � � S � _ S �w� s se �n�a s g g _ -� s s�� ae s j � a ProJectSite €, ��� s ,,... sw,�. s� �� � � � `'�'a,. a �.w, s, s......v. n, � �:gyp � N _ i a � �� a I � li sw�hs .,f � a a$ � � se ro� s ��� § E � ef.� s �` se N � "O none sf � Ff hs ��',v 3 sE fam a��W JTE, I11C. GRANT PLACE TOWNHOMES - RENTON FIGURE 1 SITE ACCESS/TRAFFIC IMPACT FEE TRAFFIC LETTER VICINITY MAP Project: Grant Place Townhomes -Renton Location: 1600 Grant Avenue South NORTH Milb�a�At Arghwt e.Uy, I`n cy, P.L r �� _ s�P Note: An 8.5 x Si' copy of the Site Plan Is inclutletl with Nis letter report. JTE, IIIC. GRANT PLACE TOWNHOMES - RENTON FIGURE 2 SITE ACCESS/TRAFFIC IMPACT FEE TRAFFIC LETTER SITE PLAN m wilmom ml �� Washington State rrnnwonaaon ewmina �// Da artmont of 7Yans rtation 310 Maple Park Avanua S.E. P i� P.O. Boz 4)300 gymPle. WA 965o4-]300 Lynn Peterson 360-]05-]000 SecrHary of Transponation TIM. 1-Boo-tq3-6366 www.wsEotwa.gov January 13, 20I4 Mr. Mark 1. Jacobs —JTE Inc 2614 39a' Ave S W Seattle WA 98116 Re: Collision Data Dear Mr. Jacobs: In response to your January 6 request, we have prepared a history of officer reported collisions that occurred on or in the vicinity of Gmnt Ave in the City of Renton for the period of 1/ I /2010 — 11/30/2013 (November oj20/3 is the mos! current complete momh proces•.ved). Federal law 23 United States Code Section 409 governs use ofthe data you requested. Under this law, data maintained for purposes of evaluating potential highway safety enhancements: ... shot! not he suhject to discovery or admitted into evidence in a federal or state court proceeding or considered jor other purposes in any action jor damages arising from any occurrence at a location mentioned or addressed in such reports, surveys, schedules, lists, or data." [Emphasis added.] The Washington State Department of Transportation (WSDOT) is releasing this data to you with the understanding that you will not use this data contrary to the restrictions in Section 409, which means you will not use this data in discovery or as evidence at trial in any action for damages against the WSDOT, the State of Washington, or any otherjurisdiction involved ur the locations mentioned in the data. If you should attempt to use this data in an action for damages against WSDOT, the State of Washington, or any other jurisdiction involved in the locations mentioned in the data, these entities expressly reserve the right, under Section 409, to object to the use of the data, including any opinions drawn from the data. If you have any further questions you may contact me at 360-570-2490. Sincerely, Geneva Hawkins Collision Data Analyst Statewide Travel &Collision Data Office /Multi -modal Planning Division N N C O C !� �s �s �� __ . ,..., a �s w N �� s �o &z � h uw'i 3S antl 418ZI € y F �° � r„ ur 3S any WSZL a O N w � N q2 �.r� 3s any 410Z1 O,qr. g/ �1 �S SF' in `� 3S any 4181 q O W f� ♦ t7 2 E� Jea j y "nS 3S antl 41t 11 �yG� V orv�� o'es w � yF' t � � a N �.� w u — San ue N � 35 antl 41901 a � 0 N $ any VIEW ,. � nn 5 , Ja y . P g any sweIIIM � �/ Benson ,. „ M^, AP S Pa loglal Benson Dr S ,j+ N N N i� v N � .. 3� rn y N '. w N � 5 S any YonNa4S Talbot {id S C � C v � .. 1- ry n N Rrnj..felle dN N N N n vauar Fwv Pa ,callan 4t r T � N e � �' a' MS any Puf Q `C 4 N �/ N � ry N � � n a� � m` N '� e N S Q 3 3 � � � 3 s :. ffi °' � 3N N MS any alePsaHeO y n y � m�u Ns � � may U N � 9 rn � _ [.... �....... .. ZdIY� � B 1 z 7% glaahbrgipp state Request for Collision Data Deparlmerd o1 7Yansportation Please complete this request loan and mail or fax to the address shown below. In order to ensure efficient service. please provide as much information es you can in your request If can ram�ira addainnal information In rmm�late your request, we will contact you. The Washington State Department of Transportation maintains a statewide database for all reported imffc collisions, beginning with collisions occurring in 2002. In addition. collision data for interstate and state highways only is available for collisions occurring from 1993 to the present. This data includes such items as collision location, dale, time, seventy, weather and light conditions, as well as information on tlrivers, pedestrians, bicyGists and property owners involved in collisions. Federal highway safety laws require the state to create this collision database for use In obtaining fetleral safety Improvement (ands. Under Section 409 of Title 23 of the United States Code, collision data is prohib{led from use in any litigation against slate, tribal or local government that involves the locations) mentioned in the collision data. By checking the hox helow, you agree to comply with Mese temps -failure to do so will be grounds for denying your request. �I hereby affirm that I am not requesting this collision data for use in any current, pending or anticipated litigation against slate. tribal or local govemment involving a collision at the localion(s) mentioned in the data. Requestor Information Lest Name �A C aQS First N �'Z/�r2� M Company/Agency Name J 1NC Atltlress 3 s h i¢„� S� City S� stale u� zip Cade 9Pii6 Phone No. Fax No. Email Description of Collision Data Requested Use the space below Ie descdbe your request. II applicable, please include the following. • Beginning and entling dales for the desired data. • Names of locations or individual highways, roads or streets desired. • In what format you would like the data. e.g.. a history report that gives mformalion about each wllision; a summary report by year or by month', or a summary for specific data elements, such as light wnd9lons, That were experienced during the collisions. 3 �-s.�� �e0/o-2dyL.�'t ..✓.,�.Le Luy3 fay /Le.:��., Vr Mail or Fax your completed request form to-. COLLISION DATA 8 ANALYSIS BRANCH WASHINGTON STATE DEPARTMENT OF TRANSPORTATION P.O. BOX 4]3e1 3 � � r l f —& OLVMPIA WA 96504-47381 e O I ,�.� Z� J � '� f a,� Fax: 360-570-2449 'l •1 I t If you have any questions, please call (360) 570-2454 yl ,.� I � I� /J oor a�,'mB6vxoo`s L [ .-y i " 0.�11�"' 3rP`'t ��� \\\))(§\\k§ \) j) E! §§ ii\§§maml;, (!!!!f!|!! §§§ ; �"e!!!I!!!!k /\ \\\ \ �//\\\i\// \\\\ § )))) /}\\\\\\ } \ } } (/ { k } \\}\\\\}\ !§!;!!!!/!!!; \:\\\:/\:} �/{\\\\//\ \ \ ! \{{{ } \ \ �\{\\\\\}\ _ �//�/��/ §\\k\}\\}k { } \{//} k -)!!&����(� -f!!!!«-! (\\%!#!!\ƒƒ §����\\\\�/ k }__\\\\\\ » j\j;!!!!! @ $/!7! m !!!)! V11. Other Permits Other permits include water and sewer franchise utility permits and right of way improvement permit as required by the City of Renton. 47 Vill. CSWPPP Analysis and Design ESC Plan Analysis and Design (Part A) TEMPORARY EROSION AND SEDIMENT CONTROL 1. The grading for this project is only limited to the onsite improvement and offsite frontage improvement. Temporary Erosion and Sedimentation Control will be provided by utilizing BMPs selected from the 2009 King County Surface Water Design Manual. These BMPS will likely include, but are not necessarily limited to construction entrance for traffic stabilization, silt fencing for parameter protection, plastic sheeting of stockpiles, straw mulch, hydro -seeding of exposed areas, catch basin protection, etc. All new impervious areas and new pervious areas will be treated by a combined detention/wet vault for Level 2 flow control and treated by a treatment train of wet vault and StormFilter manhole for enhanced basic water quality treatment. At the beginning of the construction, construction entrance and silt fence along the grading limit will be installed. Then, combined detention/wet vault will be installed. The excavation of the vault and the vault itself can be used as temporary sediment trap during construction period. Temporary erosion and sediment control facilities will be maintained during construction period and will be removed after construction is finished. See Temporary erosion and sediment control plan, notes and details at the construction plan set for more details. Also see attached Stormwater Pollution Prevention and Spill (SWPPS) plan. 2. The site is hilly, no sensitive area exist onsite. No special measure is proposed. Temporary sediment trap sizing: Q2y using KCRTS method with 15-minute time step: 48 ' Lend Use Summary I o ( ' -' 1 J .._area -- ? Till Forest 0.00 acres Till Pasture 0.00 acres Till Grass 0.73 acres Outwash Forest 0.00 acres Outwash Pasture 0.00 acres Outwash Grass 0.00 acres Wetland 0.00 acres Impervious 1.38 acres 2.11 acres Scale Factor: 1.00 15-Min Reduced Edit Flow Paths Time Series: Rev-l5.tsf }} Compute Time Series Modify User Input Flow Frequency Analysis Time Series File:dev-15.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.657 6 8/27/01 18:00 0.464 8 1/05/02 15:00 1.41 2 12/08/02 17:15 0.529 7 8/23/04 14:30 0.791 4 11/17/04 5:00 0.783 5 10/27/05 10:45 0.916 3 10/25/06 22:45 2.00 1 1/09/08 6:30 Computed Peaks -----Flow Frequency Analysis -- - - Peaks - - Rank Return Prob (CFS) Period 2.00 1 100.00 0.990 1.41 2 25.00 0.960 0.916 3 10.00 0.900 0.791 4 5.00 0.800 0.783 5 3.00 0.667 0.657 6 2.00 0.500 0.529 7 1.30 0.231 0.464 8 1.10 0.091 1.80 50.00 0.980 Q2y = 0.657 cfs Required surface area = 2080 * Q2y = 2080 * 0.657 = 1,367 sf. The proposed temporary sediment trap is located at the northwest corner of the site. A temporary overflow path is provided to over flow to the existing 12" CMP culvert inlet at the Grant Avenue South near existing catch basin SDMH#1. 49 EROSION AND SEDIMENT CONTROL STANDARDS: ESC measures shall be applied and maintained to prevent, to the maximum extent practicable, the transport of sediment from the project site to downstream drainage systems or surface waters. This performance is intended to be achieved through proper selection, installation, and operation of the above ESC measures as detailed in the ESC Standard (detached Appendix D) and approved by the City of Renton. PERMANENT EROSION AND SEDIMENT CONTROL For Permanent Erosion and Sedimentation Control, access driveways, fire lane and walkways will be paved. Landscape areas will be covered with grass, trees and ground covers. All onsite new impervious areas and new pervious areas will be treated by the combined detention/wet vault for Flow control (Level 2, forest existing condition) and a treatment train of combined detention/wet vault and StormFilter manhole with CSF cartridges for Enhanced Basic water quality treatment. 50 STORMWATER POLLUTION PREVENTION AND SPILL (SWPPS) PLAN (Part B) 51 Stormwater Pollution Prevention Plan for Construction STORM WATER POLLUTION PREVENTION PLAN GRANT AVENUE TOWNHOMES RENTON, WASHINGTON, USA Prepared for Northwest Regional Office 3190 - 160th Avenue SE Bellevue, WA 98008-5452 425-649-7000 May 30, 2017 Prepared by Pacific Engineering Design, LLC. 15445 53rd Avenue South, Suite 100 Seattle, WA 98188 Phone: (206) 431-7970 PED Job number: 13043 SWPPP Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information is, to the best of my knowledge and belief, true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. �� D /z ol Jingsong,g, P.E'. Project Engineer SITE CONTACT INFORMATION SITE OWNER PHONEIFAX/MOBILE ADDERSS Skyline Properties, Inc. (425) 455-2065 50116t1' Avenue SE, Suite 120 Bellevue, WA 98004 PROJECT CONTRACTOR To be determined PROJECTEROSIONLEAD 24 HOUR CONTACT To be determined To be determined Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities Revision Schedule This storm water pollution prevention plan (SWPPP) should be revised and updated to address changes in site conditions, new or revised government regulations, and additional on -site storm water pollution controls. All revisions to the SWPPP must be documented on the SWPPP Revision Documentation Form, which should include the information shown below. The authorized facility representative who approves the SWPPP should be an individual at or near the top of the facility's management organization, such as the president, vice president, construction manager, site supervisor, or environmental manager. The signature of this representative attests that the SWPPP revision information is true and accurate. Previous authors and facility representatives are not responsible for the revisions. SWPPP Revision Documentation Form Number Date Author Company Representative Signature 0 1 2 3 4 5 6 7 8 9 10 Pacific Engineering Design, LLC. CONTENTS LIST OF FIGURES AND DRAWINGS iv 1 CONSTRUCTION ENVIRONMENTAL SUMMARY 1-1 1.1 Summary 1-1 2 INTRODUCTION 2-1 2.1 Storm water Pollution Prevention Plan Requirements 2-1 2.2 Purpose 2-1 2.3 SWPPP Organization 2-1 3 CLEARING LIMITS 3-1 3.1 Site Plans 3-1 3.2 Marking Clearing Limits 3-1 3.3 Special Consideration 3-1 3.4 Selected BMPs 3-1 4 CONSTRUCTION ACCESS 4-1 4.1 Site Access 4-1 4.2 Street Cleaning 4-1 4.3 Wheel Wash 4-1 4.4 Selected BMPs 4-1 5 STORM WATER DETENTION 5-1 5.1 Primary Storm water Detention System 5-1 5.2 Run-on Bypass 5-1 6 SEDIMENT CONTROLS 6-1 6.1 Site Sediment Control System 6-1 6.2 Selected BMPs 6-1 7 SOIL STABILIZATION 7-1 7.1 Soil Stabilization 7-1 7.2 Structural BMPs 7-2 8 SLOPE PROTECTION 8-4 8.1 General Practices 8-4 8.2 Suggested BMPs 8-4 Pacific Engineering Design, LLC. i CONTENTS (Continued) 9 DRAIN INLET PROTECTION 9-1 9.1 Existing Storm Drains 9-1 9.2 Newly Constructed Storm Drains 9-1 9.3 Suggested BMP 9-1 10 STORM WATER OUTLET PROTECTION 10-1 10.1 Street Drainage along the west side of 141h Avenue SW 10-1 10.2 Bypass Drainage along the west side of 141h Avenue SW 10-1 10.3 Suggested BMPs 10-1 11 SPILL PREVENTION AND RESPONSE 11-1 11.1 General Materials Handling Practices 11-1 11.2 Specific Materials Handling Practices 11-2 11.3 Spill Response 11-2 11.4 Notification 11-4 12 STORM WATER TREATMENT 12-1 12.1 Storm Water Collection System 12-1 12.2 Temporary Sediment Traps 12-1 12.3 Monitoring Chemical Treatment System 12-1 12.4 pH Adjustment 12-2 13 BMP MAINTENANCE 13-4 14 PROJECT MANAGEMENT 14-1 14.1 Phasing of Construction 14-1 14.2 Seasonal Work 14-1 14.3 Training 14-1 14.4 Pre -construction Conference 14-2 14.5 Coordination with Utilities and other Contractors 14-2 14.6 Subcontractor Oversight 14-2 14.7 Monitoring/Reporting 14-2 14.8 SWPPP Update 14-2 FIGURES DRAWINGS ii Pacific Engineering Design, LLC. CONTENTS (Continued) APPENDIX A NPDES STORM WATER PERMIT FOR CONSTRUCTION & STATE WATER QUALITY STANDARDS APPENDIX B STANDARDS AND SPECIFICATIONS FOR SELECTED BMPs APPENDIX C MATERIAL SAFETY DATA SHEETS Pacific Engineering Design, LLC. iii FIGURES AND DRAWINGS Figures 1 Site Topography Map 2 Storm water Site Map Drawings C01 Cover Sheet CO2 Overall Plat Plan CO3 Grading and Drainage Plan C04 Composite Utility Plan C05 Tree Retention Plan Following Report Pacific Engineering Design, LLC. 1v Storm Water Pollution Prevention Plan for Construction Activities 1 CONSTRUCTION ENVIRONMENTAL SUMMARY 1.1 Summary Beginning in Summer 2016, Skyline Properties, Inc. is starting the Grant Avenue Townhomes construction project located on 1600 Grant Avenue South in City of Renton, Washington. The site area is 2.11 acres. The existing residence on the site will be removed for this development. The project will construct 8 new multi -family apartment building complexes (total 36 units), access roads and walkways, street frontage improvement with new sidewalk along Grant Avenue South, landscaping and associated utilities. Duration (forest existing condition) flow control and Enhanced Basic water quality treatment are required for this project. A combined detention/wet vault is used to provide the required Flow control. A treatment train of combined detention/wet vault and StormFilter manhole with CSF cartridges is used to provide the required water quality treatment. The conveyance system is designed to have the capacity to handle 100 year 24 hour peak flow. There is no sensitive area in the site or near the site. Because more than 5,000 square feet of new impervious area is proposed, extra protective measures have been established to ensure there is no adverse impact to water quality in the surrounding area. This Storm water Pollution Prevention Plan details all of the protective environmental measures, which will be employed during construction of the project. Perhaps most innovative and protective of all measures designed for use is the storm water treatment system which treats all storm water collected during construction to produce clear, clean, and non -toxic water for discharge into the drainage basin stream. Designed as an integrated Best Management Practice (BMP) to complement the other BMPs described in this plan, the storm water treatment system provides a fail-safe method for ensuring only clean water leaves the site. 1.1.1 Project Description Total project area is 2.17 acres (2.11 acres onsite, 0.06 acres offsite frontage improvement). Total proposed impervious area is 1.41acres (1.38 acres onsite, 0.03 acres offsite), proposed areas to be disturbed is 2.17 acres (2.11 acres on site, 0.06 acres Pacific Engineering Design, LLC. 1-1 Storm Water Pollution Prevention Plan for Construction Activities offsite). Total volumes of proposed cuts are approximately 4,240 cy and total volumes of proposed fill are approximately 3,680 cy. Net earth work exported is approximately 560 cy. 1.1.2 Existing Site Conditions There is a single family house (built 1946) on the west portion of the site near the Grant Avenue South. The house will be demolished and removed for the proposed development. The remainder of the property is covered with grass with some scattered trees. The site is hilly with average slope of 11 % slopes westerly toward Grant Avenue South. The properties east and south of the site have their own drainage system to intercept runoff before it reach the site. The property north of the site slopes westerly to Grant Avenue South parallel with the site. The properties west of the site are located at elevations lower than the site. The site does not receive significant upstream runoff from adjacent properties. Under existing condition, the site sheet flows westerly to Grant Avenue South. The low point of Grant Avenue South is located near the northwest corner of the site where there are two type 1 catch basins at both sides of the street to collect street runoff. The street drainage system drains to a storm manhole (SDMH#1) near the northwest corner of the site. SDMH#1 has an 18" outfall pipe that discharges westerly to Thunder Hills Creek. The 0.25 mile downstream point is located at the Thunder Hills Creek. The 1 mile downstream point is located at the city storm drainage system that drains to Springbrook Creek. No capacity problem, erosion problem and water quality problem were found within 0.25 miles downstream of the site. 1.1.3 Adjacent Areas Adjacent areas that may be affected by the runoff of sediment -contaminated water are the Grant Avenue South and the Thunder Hills Creels directly west of the site. Under developed condition, onsite runoffs will be collected and conveyed to the onsite detention and water quality treatment system before discharged to the Grant Avenue South storm drainage system and Thunder Hills Creek. During construction, silt fences will be installed along the south and west property lines of the site to prevent sediment - contaminated runoff leaving the site. Excavation for the combined detention/wet vault will be used as temporary erosion and sediment pond. Temporary intercept ditches will be installed to intercept onsite runoff and direct it to this temporary erotion and sediment pond. Pacific Engineering Design, LLC. 1-2 Storm Water Pollution Prevention Plan for Construction Activities 1.1.4 Critical Areas There is no critical area in the site or near by the site. 1.1.5 Soils According to the City of Renton Soils Map and King County Soils Map, on site soil is till soil (Alderwood Gravelly sandy loam, Agl) (15 to 30% slope) on the west portion of the site and AgC (8 to 15% slope) on the east portion of the site) and infiltration is not feasible for this site. 1.1.6 Erosion Problem Areas The site is hilly with average slope of approximately II% across the site. Potential for erosion problem is moderate on the east portion of the site and severe on the west portion of the site. The west portion of the site is mapped as erosion hazard area on the City of Renton Erosion Hazard Area Map and moderate landslide hazard area on the City of Renton Landslide Hazard Area Map. 1.1.7 Construction Phasing The construction may be divided to two phases: Onsite development. 2. Offsite frontage improvement. 1.1.8 Construction Schedule The construction will happen in dry season total construction time will be 5 to 6 month. If wet season land disturbance is proposed, see section VIII of this TIR for wet season special provitions. 1.1.9 Financial/Ownership Responsibilities The property owner is responsible for the initiation of bonds and/or other financial securities and the bonds and/or other evidence of financial responsibility for liability associated with erosion and sedimentation impacts. Pacific Engineering Design, LLC. 1-3 Storm Water Pollution Prevention Plan for Construction Activities 1.1.10 Engineering Calculations See section IV of this TIR for the design calculations for the sizing of storm water detention facilities and storm water treatment facilities. See section V of this TIR for the sizing of the conveyance system. Pacific Engineering Design, LLC. 1-4 Storm Water Pollution Prevention Plan for Construction Activities 2 INTRODUCTION 2.1 Storm water Pollution Prevention Plan Requirements This Storm water Pollution Prevention Plan (SWPPP) is developed consistent with the requirements of the National Pollutant Discharge Elimination System (NPDES) General Storm water Permit for Construction Activities (see Appendix A for a copy of the general permit). This SWPPP meets the requirements of Special Condition S9 of the general permit. The primary consideration determining the adequacy of the SWPPP is compliance with State Surface Water Quality Standards (Chapter 173-201A — see Appendix A). The Plan, properly implemented, should result in the discharge of water to the environment without the violation of Water Quality Standards. 2.2 Purpose The purpose of this SWPPP is to: • Describe best management practices (BMPs) to minimize erosion and sediment runoff at the site • Identify, reduce, eliminate, or prevent the pollution of storm water • Prevent violations of surface water quality or groundwater quality standards 2.3 SWPPP Organization This plan consists of a detailed narrative section and the appendices, which contain illustrations, maps, and drawings. The narrative section includes descriptions of potential pollution problems associated with site features, and then discusses the selection of specific pollution prevention BMPs to reduce or eliminate the threat of causing pollution during the actual construction project. The illustrations, maps, and drawings in the appendices show the site location, topography, sensitive environmental receptors, placement of BMPs, and BMP specifications and performance expectations. Pacific Engineering Design, LLC. 2-1 Storm Water Pollution Prevention Plan for Construction Activities The narrative section of this plan is organized in numbered sections around the 12 required elements of an SWPPP listed below: 1. Mark project clearing limits 2. Establishing the construction entrance(s) 3. Storm water detention 4. Selection and installation of sediment controls 5. Soil stabilization 6. Slope protection 7. Drain inlet protection 8. Storm water outlet protection 9. Chemical spill prevention and response 10. Site Storm water Treatment 11. BMP maintenance 12. Project management In the narrative section, each of the above elements will be discussed in relation to the specific conditions at the development. BMPs for each element will be screened, resulting in selection of those BMPs deemed most appropriate for use. Specifications and engineering drawings of the selected BMPs are referenced at the end of each section and can be found in Appendix B. Pacific Engineering Design, LLC. 2-2 Storm Water Pollution Prevention Plan for Construction Activities 3 CLEARING LIMITS 3.1 Site Plans Figure 1 is a topographic map of the site showing all natural drainages associated with the area. Figure 2 is the Storm water Site Map showing any surface water in the area and showing placement of all relevant storm water BMPs such as combined detention/wet vault, storm drains, spill kit locations, storm water treatment system location, etc 3.2 Marking Clearing Limits Prior to beginning earth -disturbing activities, including clearing and grading, all clearing limits, easements, setbacks, sensitive areas and their buffers, trees and drainage courses will be clearly marked to prevent environmental damage both on and off site. 3.3 Special Consideration Special consideration will be given to the boundaries of the drainage basin on the site. 3.4 Selected BMPs • BMP C 101: Preserving Natural Vegetation (total 11 existing trees and surrounding vegetation will be preserved) • BMP C103: Plastic or Metal Fence • BMP C104: Stake and Wire Fence (used to marls temporary construction limits) • BMP C233: Silt Fence Pacific Engineering Design, LLC. 3-1 Storm Water Pollution Prevention Plan for Construction Activities 4 CONSTRUCTION ACCESS 4.1 Site Access Two temporary stabilized construction entrance will be installed at the location of the two proposed driveway entrances near the southwest and northwest corners of the site. All construction vehicles exiting the site will be limited to these accesses. The accesses are stabilized with gravel to prevent tracking sediment onto Grant Avenue South. 4.2 Street Cleaning If sediment is accidentally transported on to the street it will be removed from the street surface on a daily basis. Sediment will be shoveled and/or swept from the street and disposed of in a manner, which prevents contamination with storm water or surface water (e.g., covered soil stockpile). In addition, a street sweeper may be used to maintain clean roads on an as -needed basis. 4.3 Wheel Wash Based on site conditions and time of year, a temporary truck wheel wash station may be constructed to ensure control of sediment at the construction exit point. The wheel wash system (if needed) will be constructed on the site at a location just prior to where trucks leave the site access and enter the street. The system will consist of an asphalt -lined wash pond for immersing the truck tires as the truck drives through and a small settling pond for settling suspended sediment in wash water cycled out of the system. Wash water may be reused after settling, infiltrated onsite, or transported off site for disposal. Accumulated sediments will be collected periodically, stockpiled for dewatering, then reused onsite. 4.4 Selected BMPs • BMP C 105: Stabilized Construction Entrance • BMP C 106: Wheel Wash (wet season only) • BMP C 107: Construction Road/Parking Area Stabilization Pacific Engineering Design, LLC. 4-1 Storm Water Pollution Prevention Plan for Construction Activities 5 STORM WATER DETENTION 5.1 Primary Storm water Detention System The construction site slopes westerly towards Grant Avenue South. Under developed condition, The onsite detention tanks will provide Level 2 (Duration with forest existing condition) Flow control for the project site. During construction period, The excavation for the combined detention/wet vault will be used as a temporary erosion and sediment control pond, all storm water contaminated with sediment or otherwise affected by construction activities will be directed to this temporary erosion and sediment control pond. The detained release will be discharged to the Grant Avenue South storm drainage system which is discharged to the Thunder Hills Creek. 5.2 Run-on Bypass No significant upstream area drains to the site. No BMPs are selected. Pacific Engineering Design, LLC. 5-1 Storm Water Pollution Prevention Plan for Construction Activities 6 SEDIMENT CONTROLS 6.1 Site Sediment Control System Before being discharged from the construction site, sediment -contaminated storm water will be processed in the storm water treatment system. Clean water bypassing the site will be routed directly to the Grant Avenue South receiving storm drainage system. A temporary erosion and sediment control pond will be installed near the west property line using the excavation for the combined detention/wet vault. After the vault is constructed, the vault itself can be used for temporary erosion and sediment control. Sediment barriers or filters, and other BMPs intended to trap sediment on site will be constructed as one of the first steps in grading. These BMPs will be installed before other land - disturbing activities take place. 6.2 Selected BMPs • BMP C200: Interceptor dike and swale • BMP C207: Check dams • BMP C233: Silt Fence • BMP C241: Temporary Sediment Pond • BMP C250: Construction Storm water Chemical Treatment Pacific Engineering Design, LLC. 6-1 Storm Water Pollution Prevention Plan for Construction Activities 7 SOIL STABILIZATION This section describes the stabilization and structural BMPs that will be implemented to minimize erosion and transport of sediment from the project site into receiving waters. Erosion and sediment control facilities that have been approved as a part of the project's grading permit are shown in Drawing of the Temporary Erosion and Sediment Control Plan. Many of the BMPs listed below are described in the WSDOT Construction Site Erosion and Spill Control Certification Course Manual as well as in Volume 2 of Ecology's Storm water Management Manual for the Puget Sound Basin and the King County Surface Water Management Manual and have been included in Appendix B. 7.1 Soil Stabilization Stabilization BMPs to be implemented at this site include: • Soil Covering. All exposed soils will be stabilized with vegetation or covered prior to the onset of the rainy season. The primary stabilization method used will be covering soils with an approved matting and/or hydroseeding. This will be done on all slopes as well as drainage ditches, swales, and exposed flat surfaces as deemed necessary by the erosion and sediment control lead. Virtually all exposed soils will be stabilized to protect surface water quality. Areas of the project, which have not been properly stabilized by vegetation by the onset of the wet season, will be covered with transparent plastic sheeting to prevent sediment transport. Plastic sheeting will also be used as an emergency BMP to cover previously stabilized areas, which begin to erode. Loose straw and mulch covers are not to be used as they may be washed into drainage structures. • Stockpile Covering. All temporary soil stockpiles will be covered with plastic. Long-term stockpiles will be compacted and hydroseeded prior to the onset of wet weather. Clean runoff from covered or stabilized stockpiles will be collected in solid wall drainage pipe and conveyed to a surface water drainage structure. • Polymer Soil Treatment. Smaller areas of the site may be actively worked throughout the wet season to support the installation of utilities. These smaller areas of exposed soils may be temporarily stabilized with the application of a granular Pacific Engineering Design, LLC. 7-1 Storm Water Pollution Prevention Plan for Construction Activities anionic polyacrylamide (PAM). PAM may be applied as an aqueous solution (0.5 pounds per 1,000 gallons of water) or as a granular solid evenly dispersed over the surface of soils using a seed spreader (3 to 5 pounds of PAM per acre). For additional instruction and use restrictions see the WSDOT Draft Experimental BMP 5.0 - Polyacrylamide for Soil Erosion Prevention (June 21, 1999) and the WSDOT Draft Interim Criteria for WSDOT to use Polyacrylamide (PAM) (June 21, 1999) in Appendix B. • Maintenance of Existing Vegetation. Existing and new vegetation will be maintained to the maximum extent practicable to prevent the contamination of storm water with sediment. Vegetated areas beginning to show signs of erosion or soil transport will be covered with plastic sheeting and the clean runoff conveyed to a storm water drain. • Outlet Protection. Adequate energy dissipation, erosion control, and soil stabilization measures (e.g., rock or other energy dissipation techniques) will be provided for all point source discharges of storm water, including run-on discharges and outlets from onsite discharges. • Inlet protection. All existing storm drain inlets, including those made operable during the project, will be properly protected and maintained using approved inlet protection devices. 7.2 Structural BMPs Structural BMPs. Structural BMPs are practices designed to divert flows from exposed soil, store storm water runoff, and limit runoff and the discharge of pollutants from exposed areas of the project. The goal of structural BMPs on this project is to protect receiving water downstream of the site from turbid water, phosphorus, sediment, oil, and other contaminants, which may mobilize in storm water flows. • Temporarily Modified Catchment Structures. Catch basins, manholes, vaults and swales may have to be modified on a temporary basis so that dirty water can be intercepted before leaving the site. This may be done in several different ways generally resulting in temporarily blocking an outlet structure and installing a pump to transfer the storm water inflow to a settling, infiltration, or treatment system. Automatic float level controllers built into the pump prevent the pump from running dry and conserve power use. • Drainage Swales, Ditches, and Check Dams. Swales and ditches will be used on a permanent and temporary basis to convey storm water in a way that minimizes the potential for contamination by sediment. Because some sediment will Pacific Engineering Design, LLC. 7-2 Storm Water Pollution Prevention Plan for Construction Activities always be present in storm water, check dams will be used in swales and ditches to reduce the velocity of the water and allow some settling of larger particles. • Sedimentation Swales and Ponds. Temporary and permanent swales and small sedimend ponds will be used as necessary to reduce the velocity of runoff and enhance particle settling. Pacific Engineering Design, LLC. 7-3 Storm Water Pollution Prevention Plan for Construction Activities 8 SLOPE PROTECTION 8.1 General Practices Cut and fill slopes on this project have been designed and will be constructed so as to minimize erosion. Soil types have been analyzed and considered for their potential to erode also. In addition, slope runoff velocities will be reduced by terracing, creating diversions, and surface contouring. Upslope drainage and uncontaminated run-on water from off -site will be intercepted at the top of the slope and diverted around the active construction area. Down slope flows will be contained in pipes, slope drains, and/or stabilized channels. 8.2 Suggested BMPs Because the site is hilly, slope protection is required for this project. The following BMPs are selected. • BMP C120: Temporary and Permanent Seeding • BMP C 121: Mulching • BMP C130: Surface Roughening • BMP C131: Gradient Terraces • BMP C200: Interceptor dike and swale • BMP C204: Pipe Slope Drains • BMP C207: Check dams Pacific Engineering Design, LLC. 8-4 Storm Water Pollution Prevention Plan for Construction Activities 9.1 Existing Storm Drains Existing storm drain inlets will be protected to prevent storm water from entering without first being filtered or treated to remove sediment. 9.2 Newly Constructed Storm Drains All storm drain inlets made operable during construction will be protected to prevent storm water from entering without first being filtered or treated to remove sediment. 9.3 Suggested BMP • BMP C220: Storm Drain Inlet Protection Pacific Engineering Design, LLC. 9-1 Storm Water Pollution Prevention Plan for Construction Activities 10 STORM WATER OUTLET PROTECTION 10.1 Street Drainage along the east side of Grant Avenue South Storm water will be cleaned of sediment and other pollutants when discharged from the site to the storm drainage system that runs along the east side of GrantAvenue South. The onsite storm drainage system will be connected to the Grant Avenue South storm drainage system at existing SDMH#1 near the northwest corner of the site. 10.2 Bypass Drainage along the east side of Grant Avenue South Offsite runoff is intercepted by the existing storm drainage system that runs along the east side of Grant Avenue South and bypass the site. 10.3 Suggested BMPs • BMP C220: Storm Drain Inlet Protection. Pacific Engineering Design, LLC. 10-1 Storm Water Pollution Prevention Plan for Construction Activities U \_ •'Ll I • p • • Consistent with the general permit requirements, all potential pollutants other than sediment will be handled and disposed of in a manner that does not cause contamination of storm water. Non -sediment pollutants that may be present during construction activities include: • Petroleum products including fuel, lubricants, hydraulic fluids, and form oils • Polymer used for soil stabilization • Water treatment chemicals (coagulant, acid, sodium bicarbonate) • Concrete • Paints • Fertilizers These materials, and other materials used during construction with the potential to impact storm water, will be stored, managed, used, and disposed of in a manner that minimizes the potential for releases to the environment and especially into storm water. Emergency contacts for the project will be posted at the project office and are included at the end of this section. 11.1 General Materials Handling Practices The following general practices will be used throughout the project to reduce the potential for spills. • Potential pollutants will be stored and used in a manner consistent with the manufacturer's instructions in a secure location. To the extent practicable, material storage areas should not be located near storm drain inlets and should be equipped with covers, roofs, or secondary containment as needed to prevent storm water from contacting stored materials. Chemicals that are not compatible (such as sodium bicarbonate and hydrochloric acid) shall be stored in segregated areas so that spilled materials cannot combine and react. • Materials disposal will be in accordance with the manufacturer's instructions and applicable local, state, and federal regulations. Pacific Engineering Design, LLC. 11-1 Storm Water Pollution Prevention Plan for Construction Activities • Materials no longer required for construction will be removed from the site as soon as practicable. • Adequate garbage, construction waste, and sanitary waste handling and disposal facilities will be provided to the extent necessary to keep the site clear of obstruction and BMPs clear and functional. 11.2 Specific Materials Handling Practices • All pollutants, including waste materials and demolition debris, that occur on -site during construction will be handled in a way that does not contaminate storm water. • All chemicals including liquid products, petroleum products, water treatment chemicals, and wastes stored on site will be covered and contained and protected from vandalism. • Maintenance and repair of all equipment and vehicles involving oil changes, hydraulic system drain down, de -greasing operations, fuel tank drain down and removal, and other activities which may result in the accidental release of contaminants, will be conducted under cover during wet weather and on an impervious surface to prevent the release of contaminants onto the ground. Materials spilled during maintenance operations will be cleaned up immediately and properly disposed of. • Wheel wash water will be settled and discharged on site by infiltration. Wheel wash water will not be discharged to the storm water system or the storm water treatment system. • Application of agricultural chemicals, including fertilizers and pesticides, will be conducted in a manner and at application rates that will not result in loss of chemical to storm water runoff. Manufacturers' recommendations will be followed for application rates and procedures. • pH -modifying sources will be managed to prevent contamination of runoff and storm water collected on site. The most common sources of pH -modifying materials are bulls cement, cement kiln dust (CKD), fly ash, new concrete washing and curing waters, waste streams generated from concrete grinding and sawing, exposed aggregate processes, and concrete pumping and mixer washout waters. 11.3 Spill Response The primary objective in responding to a spill is to quickly contain the material(s) and prevent or minimize their migration into storm water runoff and conveyance systems. If Pacific Engineering Design, LLC. 11-2 Storm Water Pollution Prevention Plan for Construction Activities the release has impacted on -site storm water, it is critical to contain the released materials on site and prevent their release into receiving waters. If a spill of pollutants threatens storm water at the site, the spill response procedures outlined below must be implemented in a timely manner to prevent the release of pollutants. • The site superintendent will be notified immediately when a spill, or the threat of a spill, is observed. The superintendent will assess the situation and determine the appropriate response. • If spills represent an imminent threat of escaping ESC facilities and entering the receiving waters, facility personnel will respond immediately to contain the release and notify the superintendent after the situation has been stabilized. • Spill kits containing materials and equipment for spill response and cleanup will be maintained at the site. Each spill kit may contain: — Oil absorbent pads (one bale) — Oil absorbent booms (40 feet) — 55-gallon drums (2) — 9-mil plastic bags (10) — Personal protective equipment including gloves and goggles • If an oil sheen is observed on surface water (e.g., settling ponds, detention pond, swales), absorbent pads and/or booms will be applied to contain and remove the oil. The source of the oil sheen will also be identified and removed or repaired as necessary to prevent further releases. • The site superintendent, or his designee, will be responsible for completing the spill reporting form and for reporting the spill to the appropriate state or local agency (see Forms at the end of this section). • Facility personnel with primary responsibility for spill response and cleanup will receive training from the site superintendent. This training will include identifying the location of spill kits and other spill response equipment and the use of spill response materials. • Spill response equipment will be inspected and maintained as necessary to replace any materials used in spill response activities. Pacific Engineering Design, LLC. 11-3 Storm Water Pollution Prevention Plan for Construction Activities 11.4 Notification In the event of a spill, make the appropriate notification(s) consistent with the following procedures: • Any spill of oil which 1) violates water quality standards, 2) produces a "sheen" on a surface water, or 3) causes a sludge or emulsion must be reported immediately by telephone to the National Response Center Hotline at (800) 424-8802. • Any oil, hazardous substance, or hazardous waste release which exceeds the reportable quantity must be reported immediately by telephone to the National Response Center Hotline at (800) 424-8802. • Any spill of oil or hazardous substance to waters of the state must be reported immediately by telephone to the Washington State Department of Ecology at (360) 407-6000 (Olympia), (425) 649-7000 (Bellevue). • Any release of a hazardous substance that may be a threat to human health or the environment must be reported to the Washington State Department of Ecology at (360) 407-6000 (Olympia), (425) 649-7000 (Bellevue) immediately upon discovery. Pacific Engineering Design, LLC. 11-4 Storm Water Pollution Prevention Plan for Construction Activities 12 STORM WATER TREATMENT 12.1 Storm Water Collection System During all phases of construction and grading the contractor will provide storm water collection and conveyance systems to collect and direct sediment contaminated water to temporary sediment pond as needed to prevent offsite discharge of sediment laden storm water. Construction will occur in phases as much as practicable to avoid unnecessarily exposing vegetated areas of the site. Clean storm water, generated from stabilized and undisturbed portions of the site, will be collected and conveyed to stabilized discharge areas whenever necessary to avoid contact with disturbed portions of the site. All conveyance and collection systems will be constructed consistent with State and local BMP requirements. 12.2 Temporary Sediment Traps During construction, sediment contaminated storm water will be conveyed to temporary sediment traps, as designed by the project engineer and shown on the temporary erosion and sediment control (TESC) plan. The sediment traps will gravity -settle large particles down to silt size particles. Considering subsurface soil types, it is unlikely that gravity settling alone will remove all suspended particles. If settled storm water does not meet state water quality standards, the storm water will be managed by chemical treatment. An experienced expert in storm water treatment will perform chemical treatment. Many of the chemicals utilized for this type of treatment (polymers) can be environmentally hazardous. 12.3 Monitoring Chemical Treatment System As with all effective BMPs, the chemical treatment system requires regular monitoring to assure the overall effectiveness of storm water management. The key monitoring requirements of the chemical treatment water management system include: • Sediment Trap/pond Monitoring Pacific Engineering Design, LLC. 12-1 Storm Water Pollution Prevention Plan for Construction Activities All sediment trap(s)/pond(s) should be visually monitored at least daily during the wet season or as needed to monitor the level and quality of water within the sediment traps. The site operator will designate site personal to routinely monitor the level of the sediment trap such that the water level is not allowed to reach levels approaching discharge. The sediment traps will also be monitored weekly or as needed for sediment accumulation, functionality, and for other required maintenance. In the event of abnormal conditions, site personal will immediately report the information to the site superintendent for resolution. • Pump and Mechanical System Monitoring The pump or pumps that operate the storm water management system require routine monitoring to ensure the continual performance of the system. The contractor will follow all manufactures recommended inspection and maintenance procedures throughout the life of the project. During the wet season, site personal will monitor pump systems for correct operation, adequate power supply, and correct float level control operation. Severe storm events may require more frequent inspections, especially if pumps rely on utility -supplied power. The contractor will have available onsite or within reasonable distance to site 24-hour-a-day available backup equipment including but not limited to a pump and generator. In the event of mechanical equipment failure, the site operator will immediately take all necessary actions to replace any malfunctioning components so as to restore the original capacity of the water management system. • Water Quality Monitoring Water quality monitoring will be performed to demonstrate that the water management process is working properly, to document the quality of water discharged to the stream, and to document the background water quality of the stream. The effectiveness of the water management system will be monitored on a daily basis, recorded on the Water Management Log form, and reported to regulatory authorities as needed. State water quality standards require treated water to not exceed 5 NTU above the receiving water and the pH to be within 0.3 pH units of the receiving water. Therefore, the Storm water Monitoring Form will be used to record the receiving water background turbidity and pH as well as the quality of water discharged from the site. This information can then be used to document compliance with water quality standards. 12.4 pH Adjustment The most likely pH upset condition will be high pH resulting from concrete contamination. Acid or dry ice (CO2) will be required to neutralize the high pH. Begin recirculating the water in the basin to be neutralized while slowly adding acid (dry ice). Acid (dry ice) quantity will be calculated based on a sample test neutralization. Pacific Engineering Design, LLC. 12-2 Storm Water Pollution Prevention Plan for Construction Activities Caution! Hydrochloric and sulfuric acids are powerful acids, which can cause serious, permanent damage to human skin and eyes. See Material Safety Data Sheets in Appendix D. Goggles, gloves, and protective clothing are mandatory when handling acid. An eye wash unit is stationed in the job trailer. Acid must always be stored, moved, and dispensed in the secondary unit containment provided. No more than 5 gallons of acid will be stored on site at any time. Check pH in the treatment basin frequently after incremental additions of acid or dry ice to ensure the pH is not over -adjusted. Adjust the pH to 7.0 to 7.5. Once the desired pH has been achieved, let the basin settle briefly and check the pH again. A low pH condition may be treated by adding a 20 percent sodium bicarbonate solution as above. Check the pH after incremental additions of sodium bicarbonate. The sodium bicarbonate quantity may be calculated based on a simple jar test to determine the correct amount for size of the pond. Pacific Engineering Design, LLC. 12-3 Storm Water Pollution Prevention Plan for Construction Activities 13 BMP MAINTENANCE All temporary and permanent erosion and sediment control BMPs will be maintained and repaired as needed to assure continued performance of their intended function. All maintenance and repair will be conducted in accordance with BMPs. Recommended BMP maintenance requirements are listed in Tables 1 and 2 included in this section. Following Tables 1 and 2 is a BMP Inspection Checklist for use in routine inspections of the construction site. All temporary erosion and sediment control BMPs will be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment will be removed or stabilized on site. Disturbed soil areas resulting from removal of BMPs or vegetation will be permanently stabilized as soon as possible. Pacific Engineering Design, LLC. 13-4 Storm Water Pollution Prevention Plan for Construction Activities 14 PROJECT MANAGEMENT Implementation and management of the environmental aspects of this project under the SWPPP are the responsibilities of The Development Company and the prime contractor. Communication between all parties performing work on the site is essential for proper implementation of the SWPPP. The prime contractor, utility installation contractor, and grading contractor should all be familiar with the SWPPP and their responsibilities under the plan. To help delegate these responsibilities the following outline has been provided: 14.1 Phasing of Construction The project has been planned at this point in two phases to reduce the environmental impact of mass grading. Phase one will result in the development of the offsite improvement. During this time the site will remain undisturbed most of the time. Once the offsite improvement phase is nearing completion the onsite improvement phase will begin. From the beginning of construction until the completion of phase two, the storm water treatment system will remain operational to purify storm water impacted by construction activities. 14.2 Seasonal Work The storm water treatment system has been designed to allow for work on the project during the winter months without impacting the water quality in the drainage basin to the west of the site. While not seasonal, some construction activities may need to be postponed if scheduled during ongoing storm events. Activities such as grading and trenching in areas directly adjacent to the drainage basin during rainstorms could easily result in sediment -contaminated storm water reaching the stream. This work would therefore be performed within a window of dry weather predicted on the basis of weather reports. 14.3 Training The Development Company will provide onsite training to key personnel responsible for compliance with the SWPPP. The contractor's superintendent and project manager will be familiarized with the major elements of the plan. Construction workers and others at Pacific Engineering Design, LLC. 14-1 Storm Water Pollution Prevention Plan for Construction Activities the site will be given appropriate training information at the conclusion of site safety meetings or on an as -needed basis. 14.4 Pre -construction Conference One or more pre -construction meetings will be held with an explicit agenda item addressing the SWPPP. 14.5 Coordination with Utilities and other Contractors All contractors providing services on the project which may cause storm water pollution will be given a copy of the SWPPP and appropriate training regarding storm water pollution prevention. 14.6 Subcontractor Oversight Subcontractor oversight to ensure compliance with the SWPPP will be provided by the prime contractor's superintendent or project manager.. Informal, on-the-job tailgate training will be the first level of communication followed by onsite observation of training compliance. Non-compliance with SWPPP policies will trigger a more intensive training session to correct the problem(s). Chronic non-compliance with SWPPP policies may require the intervention of local and/or state regulatory personnel. 14.7 Monitoring/Reporting Water quality conditions at the site will be monitored by a qualified technician and water quality reports submitted to the proper regulatory authorities on a regular basis. Additional reports such as erosion and sediment control inspections will be the responsibility of the prime contractor or a designated consultant. Spill reports will be completed and submitted by the prime contractor on the project. The SWPPP will be updated as requested by The Development Company. Pacific Engineering Design, LLC. 14-2 Storm Water Pollution Prevention Plan for Construction Activities FIGURES Here include Figure 1 (Site Topographic Map) Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities Here Include Figure 2 (Storm water Site Map) Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities DRAWINGS Here include appropriate engineering drawings such as temporary esc, detention basin, tire wash, construction entrance%xit or any other drawings prepared specifically for the project. Pacific Engineering Design, LLC. 0 rn C') O ,It 1w Tr a U) W 2 0 z 0 W CL 17- z (D co O W W U) � I N / I TEMPORARY CATCH I I BASIN INSERT (TYP) PER C.O.R. STD. PLAN - i-ORiiO. U2 4'4RCf-1 202. ,5 9M3 - " TEMPORARY INTERCEPTOR DITCH I ,216.20 ON SHEET C07 TEMPORARY INTERCEPTOR DITCH PER GO.R. STD. PLAN 21ZIO - ON SHEET C07' PER C.O.R. STD. PLAN 21ZIO TEMPORARY SILT FENCE W/ROCK CHECK DAMS l l 3 SEDIMENT TRAP OUTFALL TO ON SHEET C07, PER C.O.R.' STD. PLAN 214.00 ON SHEET C07 �� ON CATCH BASIN W� ROCK CHECK DAMS PER C.O.R. STD, PLAN 217.40 I EXIS o I PER C.O.R. PLAN 216.00 , PER C.O.R. STD. PLAN 217.40 CLEARING LIMITS COINCIDENTAL ON SHEET C07 SHEET C07 ON SHEET C07 WITH NORTH PROPERTY LINE M , -- - \ \\ TEMPORARY SEDIMENT TRAP` \ \ \ SURFACE AREA=1,367 SF MIN SEE DETAIL ON PER C.O.R. STD- d PLAN 216.00 ON SHEET 07 I— — . L- _ j 2.05AC OIS7URBEO AREA - F lu �j 28 ORARY CULVERT �PORARY ROCKED S= . 100 MIN.) PLAN SEE CONSTRUCTION 15.10 ON�SHEET TAIL PER C.O.R S 07 � „ JI-1 cb v- - `` \ CLEARING LIMITS COINCIDENTAL CLEARING LIMITS TREE PROTEC77ON FENCE x ' I Wi7H SOUTH PROPERTY LINE \ ; 1 TEMPORARY INTERCEPTOR DITCH PER tC.O.R. STD., PLAN 217.10 =' > ON SHEET C07 i - _ TEMPORARY SILT FENCE W1:ROCK CHECK DAYS PF1t C.O.R. STD: PLAN 217.40 I SEE DETAIL PER C.O.R SfA rf 51._� a rl C ON"SHEET C07 14 N HEFT C07 If 7-,jACV .IiI C„NDO!'IL11Al ri i I 30 0 10 20 30 60 tl 1 m 0 ■ m m m • p5�e0 M HQp - o 1 f-000�1 � "' esigng J Iv ssOLICtvit Bngtneeriny 4��I 1 li(' I Planning Consullmn- 2 SECOND ROUND CITY REVIEW COMMENTS JF 4 JH °�`E MNiSFMt1 ac xw DATUM 1 FIRS ROUNO CITY REVIEW COMMENTS— AL JH .� FIOF I a�wc—I NO. REVISION BY DATE APPR r^*a� '� O00Op GmS1lVlRL"•' Ln 00 00 0 0 0 LO Q J APPROVED FOR CONSTRUCTION SUBJECT TO ERRORS AND OMISSIONS U) 2 BY- DATE: 0 BY. DATE: >z BY: DATE: 0 1— BY: DATE: LLI U J d� CITY OF GRANT PLACE TOWNHOMES zole-l2-z 0- RENTON ^�mum—Z z Planning/Building/Public Works oapt. TEMPORARY EROSION AND SEDIMENT CONTROL PLAN Q C06 21 0 () 1? I O LW 1-- U) W 2 0 z LO r W U n r az ILL v 1 LO r W TW 1 U) t - arastmm Fn_xcls� e w e Pn o ¢m Eiti�as�SxEa€wa E Farm Fnsac � � �� muarulnrav�VE F uuv;��mnaom � ex��a��°W o � mn�+xm arRPP+cm � � rxME 7 R=2s MN. � w,.ePPwuva n'T1�PAn w-svx -_� Ycsn Rs -III I IRII - - - - - ura aLm, �I f��unrswsot ���T � �� T°rlxw. � tsusm \ zS4 vv°Rwsrs sTEa� Pelarc Ro+nsvwvjas arclwwrasuts Poare.REe1R°B lnuvniP,R ct°rans �uuwnn �D'aPuwnr �� NDTEs 1zvM aNaaILss � ENrm.3 a>` 1. CONDIDONWUSE NOTES e°3tssAVEn, 71-- � i VF'L Ilse RssnB CEPaij \\ Xareela[n �_ it. THE RUIEPROVID ENTENS THECAT DMIL VM1ETS OdIMSLOPENIONTMW 50B FEET OFA DISNRBEO OR COtSTRUCTIONARE+,,UMF.53 TItERI THAT EMERSTHEGTCHBASW WRL BE COM-1 TDASEOL11tMPQlo ORTR1P 1. CONDMDN DFUSE 1.1. CONSTROC ENTRARPAS LLBESTABILILELLWHEREVERTRAFFICVlLLBELEAVINGACONSiRUCrIQN TRAVELING ON _) _ _ - �----__-- 12 NAY BE UGEO ANYN'HEREA0EAREAPUCAMSDIELAR OtITOPROTECTDRA2IAGE SYSTELL E NOTES SITEANO PAVED ROADS OR OTHER PAVED AREAS YARIIN TWO FEETDFTHE S(rE. S £ __=-_ ----�' Y' 13 THE COERRIBOfiNO ORABUGE AREA bgST NOT BE LARGER TtWJ1ACRE 1, CONDRmNOF USE - �_______---__-__---_ I 2. DE9pN Alm WSTALGTICN BPECffIGTpN3 1A, SILTFENCEMAYBEUSEDDOWNSLOPE OFALLDLSTURBEDAREAS, I 21. FILTER FABRCIS CNLYALLOWED WT:RE PONDING WLLttOT BEATRAFFlCCONCEMPHD VMERE SLOPE EROSION VJRI NOT RESULT IF THE 12 ttOT INTEttDEDTO TREATCGICFWTRATEO ROWS, NOR I92NENOEDTO TREATSUBSTANRALAMWM90FOVERWmFLdW. SaTFENCEE AM CONCENTRATED FLOW MOST BE COlNEYEDTHROUGNIHE OR/JNAGE SYSTEM TDASEOMEMTRM ORPONO. ALLEY BUASTSiu FNGiH n5TNO3l%SD1 atD 5A1.0.R ADs1AnM w30 mm1Ui SInNOARDStVE MEI ^- I T-rti=rtr- I CUFETOPPED BY PONOED WATER 21. THEPLACE PLACENEMOFA FILTER FABWC UNDER GRATES ICI GENERALLY PROMBREOMDIHE USE OF Fe.TER FADWCOJER GRATES IS STRICTLY LllAREO AND DISCOUftAGEA 2, DE81GNM0W8TALGDONBPEGFMATIQY9 2. DESIGNANDWSTALLATIONSPECIFICATIONS E a+FTE �� I��� �p 3. NABtTENANCE STANDARDS 21. THEGEOTEXT EUSEDNOSTM£TTHESTA40ARDUSTEDBELLONACOMOFTHEbWA1FACRR SFMMSPEC£MATIONSM BE AVAILABLE ON SITE 2.1. BSTMREO AREA THAT\Yi11BOTDE USED iN WAARYSIN FUEL M1'.'COD SASED MULCMMIS may, ) F Cy ® xy py ].1. AMACATER DTBE INLET S SHALL.NOT eE REIAOJED aml�aluo=nU URBAN ENTROADS H0E3 FUEL IS NOT RECOLIAIENDED FOR ENTRANCE SIASU]ATIOtIWURBAH AREAS ASP CT NAY FOR NOT ELI FO ENTRANCE FOR PE ATTIMEREQUWETHEUSEDFQUARRYSPMLS FTHEHOGFUELISNDTPREVENRNGSEDIMETRFROMMINGTRACKEDOWDWATER m ra Saks RBq T°y AND fi3 BE. MENT OFSITEULEUE00.1AED�ATELY.SEDWENT MOALL SEDMENT b81ST BE 043POSEOOF AS FlLLGI SITE OR HAIAEOPAVEMENTORIFTHEHOGFUELLSBEING M CARRIEDDNTOPAVEMENT.22.FENCINGSHALLBEINSTALLEDASNECESSARY TO RESTRICT TRAFFIC TO THE CONSTRUCTION ENNWiCE 23. WHENEVER POSSIBLE, THE ENTRANCE SHALL BE CONSTRUCTED ON A FIU2, COMPACTED SUBGRADE THIN CAN SUBSTANTIALLY INCREASE THE EFFECTIVENESS OF THE PAD AND REDUCE THE NEED FOR MAINTENANCE, NOTES 1, CONDIDONOFUSE 3. NNNTEHANCE STANDARDS i.t. ABEOAIFM FVIm 6HALL BE OSEO WTETEIHECONTRDUi1N0 DRAINAOEMEA 133ACRE80R VCRE 22 STANDARD SlRFNGIH FABRC REWJ2E3 WJEERACiGNGTOIJCREA3ElHESTRENGTH OF THE FENCE WWEBAC!(WGOR Cl1ISER POST 9PACWOIMY BE FEQVWED FOR EXRA 9IRENGIHFABRCF FIELD PERFORI.MVKE WARRANBABTRONGER FENCE 3.1 QUIT SPALLSSMMBEADDMFW EPADBWWNGMNACCORDANCEV"THESPECIIGTION3 32 TF THE ENTRANCE IS NDTPREVENTING SEDIMENT BEING TRAINED q'2T0 PAVEMEM,TNEN ALTERNATIVE MEASURES TD VEEP THE 2. Dp10NAND W3TAt1ATIQYBPEGFIGTgNB 2S WHER'c THE FENCEISWST ,,THESLOPESH WTBEBTEEPERTI IV STREETS FREE OF SEDIMEMSHALL BE USED THIS MAYINCLUDE STREET SWEEMNG. AN WCREASE W THE DIMENSIONS DFTHE 21, THEPCNDSHALLBEDMOEDIMOTYIOROW!4YEOEW.VOWM'e CE BYAP'cM@ABI ERTH4TY REOUCETURBULENC -AS 2<. IFATYPICAL SRT FEMCE LS USED, THESTPNDAR04%OTRENCH MAY NOT BE REOUCEDAS LONG AS THE BOTTOMS WCHESOFT1E Se.T FENCE ISMS BUREDAHDSECUREWATRENCHTIATSTABARESTHEFENCEANODOESNOTALLOWWATERTDBYPASSORUNOEWIJ E$LT ENTRANCE. ORTHE INSTALLATION OFTHEWHEELWASR FWASHWG IS USED, ITSHALL BE DONNE ON AN AREA COVERED YlRH CRUSHEDROCKANO WASHED WATER SHALL DRAIN TOASEOIhENTTRAP OR POND. ALLOYANG I.IQVE3.tE3Tf OF WATER BETWEEN CEllS.11E DNOERSHALLBEAT LEAST ONE HALF OFTHE HEIGMOF THE RISERWWE-8A 2-T03FOOTM.GKERRASTRENGTHRL FPBRCSUPPORTEDBYTREATED4- ',MAYBEU DASADN®ERPLTERNATNE NAKED 1 tMIMENMCESTMDARg3 ANYSEDILIENTTHATISTRAC MDWOPAVEVEMBHALLBEREMOVEOILWEDATELYBYSWEEPING.THESEDIMEMCOLE DBY SV1EEPINGSHALLBEREMOVEDOR$TABIUZEDGNSHE THE PAVEMENT SHALL NOT BE CLEANED BY WASHING DOWN THE STREET, EXCEPTAAHEN SWEEMG IS INEEFECTNEANDTHERE ISATHREATTD PUBLIC SAFETY. IF IT NECESSARYTD WASH THE STREETS.A STRAWBALESWRAFPEOYrtTH FILTERPNI-VAYBEUSEO 22 FTHEPD'm ISMORETNANSFEETDEEPADFFEREMMECH WMUSTBEPROPOSEO 23 TO PiDW DETERMNIhG SED'NMEMOEPTK ONEFOOT Ot1ERVAlS SFALLBE PFtOMBNENTLV MARKED ONIHE PLSER 11. ANY 04bAGESHNLBEREPAIRIMNEDA 1- SMALL SUMP MUSTBE CONDUCTED. THESMthEW W' U DT MBEWMKMIWOTHESUYP%VHERERCANBECOMROLUDM'0 32 IFCONCEMMTEO FLDESAREECEVIDENT UPH:LLOD THE FENCE, IHEYMU3TBEIMERCEPTED AFm COYVEYEOTDASEOWEl1TTRAP OR P01dl. J1 ITIS IMPORTANT TO CHECK THE UPKLL S DE OF THE FEIKE FOR SIGNS DF THE FENCE CLOGGNFL G AND ACTING AS A BARRIER TO OW AND OISCHARGED APPROPRATELY. 34, ANY QUARRY SPALLS THAT ME LOOSENED FROM THE PAD AND END UP ON THE ROADWAY SHALL BE REMOVED IMJ.EDATELY ]. MNNIENAHCESTAHDARDS RAC E 3.1. SEDU2EM SHALL BE REMIWED FROb1lHE POtm WTEN RREACIE5IFOOT WOFPIR THE FUNDS THEN CM.* CHANNEUUTION OF FLOWS PARALLEL TO THE FENCE. IF THIS OCCURS REPLACE THE FENCE OR REMOlEO THE TRAP SEDMEM. 35, IF VEHICLES ARE ENTERING OR EXITING THE SITES AT POINTS OTHER THAN THE CONSTRUCTION ENTRANCES). FENCING SHALL BE INSTALLED TD OONTROLTRAFFIC. 32 AMDANTS TO THE POND EN8OM OR SLOPES REPLACED. 34. BEDMEM MOST BE REMOVED WHEN SEDWEM IS. INCHES KOH, 3E. IF THE FILTER FABNK: (GEOTEXTILE) HAS OETERKNATED INS TO tATRAVIOLET BREAKOOWII, IT SHALL BE REPLACED PUDLIC WORKS SILT FENCE®P SILO. PLAN - 214.00 PURLIC R'oRKs STABILIZE 8t'D. PLAN - 215.10 PUDLIC WORKS S SEDIMENT POND PLAN VIEW BID. PLAN - 218.00 P®n YUDLIC WORKS FILTER FABRIC PROTECTION BID. PLAN - 216.20 )LARCH MARCH 2O08 DEPARTMENT DEPARTMENT CONSTRUCTION ENTRANCE DEPARTMENT AND CROSS SECTIONS DEPARTMENT )LARCH 2O08 MARCH 2O08 2O08 1. BEFORE ANY CONSTRUCTION OR DEVELOPMENT ACTIVITY OCCURS, A PRECONSTRUCTION MEETING MUST BE HELD WITH THE CiTY OF RENTON, PUBLIC WORKS DESIGN ENGINEER. 2. ALL LIMITS OF CLEARING AND AREAS OF VEGETATION PRESERVATION AS PRESCRIBED ON THE PLAN(S) SHALL BE CLEARLY FLAGGED IN THE FIELD AND OBSERVED DURING CONSTRUCTION. 3. ALL REQUIRED SEDIMENTATION/EROSION CONTROL FACILITIES MUST BE CONSTRUCTED AND IN OPERATION PRIOR TO LAND CLEARING AND/OR CONSTRUCTION TO ENSURE THAT SEDIMENT LADEN WATER DOES NOT ENTER THE NATURAL DRAINAGE SYSTEM. ALL EROSION AND SEDIMENT FACILITIES SHALL BE MAINTAINED IN A SATISFACTORY CONDITION UNTiL SUCH TIME THAT CLEARING AND/OR CONSTRUCTION IS COMPLETE AND POTENTIAL FOR ON -SITE EROSION HAS PASSED, THE IMPLEMENTATION, MAINTENANCE, REPLACEMENT AND ADDITIONS TO EROSION/SEDIMENTATION CONTROL SYSTEMS SHALL BE THE RESPONSIBILITY OF THE PERMTIEE. 4. THE EROSION AND SEDIMENTATION CONTROL SYSTEMS DEPICTED ON THIS DRAWING ARE INTENDED TO BE MINIMUM REQUIREMENTS TO MEET ANTICIPATED SITE CONDITIONS. AS CONSTRUCTION PROGRESSES AND UNEXPECTED OR SEASONAL CONDITIONS DICTATE, THE PERMITEE SHALL ANTICIPATE THAT MORE EROSION AND SEDIMENTATION CONTROL FACILITIES WILL BE NECESSARY TO ENSURE COMPLETE SILTATION CONTROL ON THE PROPOSED SITE. DURING THE COURSE OF CONSTRUCTION, IT SHALL BE THE OBLIGATION AND RESPONSIBILITY OF THE PERMITEE TO ADDRESS ANY NEW CONDITIONS THAT MAY BE CREATED BY THE ACTIVITIES AND TO PROVIDE ADDITIONAL FACILITIES, OVER AND ABOVE MINIMUM REQUIREMENTS, AS MAY BE NEEDED, TO PROTECT ADJACENT PROPERTIES AND WATER QUALITY OF THE RECEIVING DRAINAGE SYSTEM. 5. APPROVAL OF THIS PLAN IS FOR EROSION/SEDIMENTATION CONTROL ONLY. iT DOES NOT CONSTITUTE AN APPROVAL OF STORM DRAINAGE DESIGN, SIZE NOR LOCATION OF PIPES, Ri STTRICTORS, CHANNELS, OR RETENTION FACILITIES. 6. DURING THE TIME PERIOD OF OCTOBER 1ST THROUGH APRIL 30TH, ALL PROJECT DISTRIBUTED SOIL AREAS GREATER THAN 5,ODD SQUARE FEET, THAT ARE TO BE LEFT UN -WORKED FOR MORE THAN 12 HOURS, SHALL BE COVERED BY MULCH, SODDING OR PLASTIC COVERING. 7. IN ANY AREA WHICH HAS BEEN STRIPPED OF VEGETATION AND WHERE NO FURTHER WORK IS ANTICIPATED FOR A PERIOD 30 DAYS OR MORE, ALL DISTURBED AREAS MUST BE IMMEDIATELY STABILIZED WiTH MULCHING, GRASS PLANTING OR OTHER APPROVED EROSION CONTROL TREATMENT APPLICABLE TO THE TIME OF YEAR. GRASS SEEDING ALONE WILL BE ACCEPTABLE ONLY DURING THE MONTHS OF APRIL THROUGH SEPTEMBER, INCLUSIVE. SEEDING MAY PROCEED, HOWEVER, WHENEVER iT IS IN THE INTEREST OF THE PERMITEE, BUT MUST BE AUGMENTED WiTH MULCHING, NETTING OR OTHER TREATMENT APPROVED 13Y THE CITY OF RENTON, OUTSIDE THE SPECIFIED TIME PERIOD. B. FOR ALL EROSION/SEDIMENTATION CONTROL PONDS WHERE THE DEAD STORAGE DEPTH EXCEEDS 6 INCHES, A FENCE IS REQUIRED WITH A MINIMUM HEIGHT OF THREE (3) FEET, 3:1 SIDE SLOPES. 9. A TEMPORARY GRAVEL CONSTRUCTION ENTRANCE, 24 FEET X 50 FEET X B INCHES OF 4 TO 6 INCH QUARRY SPALLS SHALL BE LOCATED AT ALL POINTS OF VEHICULAR INGRESS AND EGRESS TO THE CONSTRUCTION SITE. Pacific hg1rj L-yjIJJ Design, Civil 15nginaariny a 1 ' Planning Consuliani3 -III= ► 111�i1=1�L-' I =M� NOTES 1. CDNDMONOFUSE 11. REQUWEDAT 11.1. THETOPOFALLSLOPESWDICEWDFMIVMDW M,O ETHAN20FEETOFVETRiC LIEF. AT INTERVALS ON ANY SLOPES THAT EXCEEDS THE DIMENSIONS SPECIFIED BELLOW AMMAGEStOPE ROPEPM FLOWPAIH U-TM 20H: LV 35M E 3W 0 BTD slap nrOMHiv - 12TOn)H:1V 21- wf- 2 DESKINANDINSTALLADONSPECIFICADDNS 21, FMSLOPESSTEEPMR NZH:IVWITNMORETFANIOFEETDFVEMICALRELIEF,BENCHES)+AY BECONSTRUCTEDORCLDSER SPACEDWTERCEPTORSWMESMAYBEUSEDTHEMREMEASUREMOSTBEDESIGNEDBYMENGWEMTOEFFEMT Y I:TFACEPTTHEHIGHVELOCITYRUNOFFTDASE [tfE PONDORTRAP. 22. CONSTRUCTION9 R RCOVERTFAIPORARYSWALESSH MMWLMII D. 3, NAINTENANCESTANDARDS 3.1. DAVAGERESULTLWFRDMRUNOFFDRCONSMUCTIONACTMTYSHALLBEREPAIREDIMMEDAMY, 32 FTHE FACIL- DO NOT REGULARLY RETAIN STORM RUNOFF, THE CAPACITY MDIOR FREQUENCYCFTHE StVALES SHALL BE INCREASED. '4 /p/I-7 PUBLIC WORKS INTERCEPTOR SWALE ErrD' PLAN - 217.10 DEPARTMENT )LARCH 2O08 NO. I REVISION I 13Y I DATE I APPR 5E AVD saEsr�TE�rnoI T 6 /Bar1oM � I NOTES 1. CDNDMONDFUSE 11. WERECONCENTRATEDRUNOFFFROMDMSN EDMR TOMDFROMPONOSORTRAPS, 12 TO CONVEY RUNOFF INTEfiCEPTED FROM UNDiSTURBEDME/S MWNO THE SITE TGAI.DN-F1105NE DISCHARGE POINT. 2 WVNTENMCESTANDARDS 21, ANYSEDIAENTDEPDSMDNOFMORETHMO5FEETSHALLBEREMOVEDSDTHATTHECHMNELISRMMEDTDRSOWIHAL DESIGN CAPACITY. 22. THE CHECK DAMS SHALL BE EXAMINED FOR SIGNS OF SOCURWG AND EROSION OF THE BED AND BANKS. IF SCOURING AND EROS HA8 OCCURRED, AFFECTED AREAS SHALL BE PROTECTED BY RIPRAP DR AN EROSION CONTROL BLANKET 1. PRE -CONSTRUCTION MEETING. 2. POST SIGN PATH NAME AND PHONE NUMBER OF ESC SUPERVISOR (MAY BE CONSOLIDATED NTH THE REQUIRED NDTICE OF CDNSTRUC71ON SIGN). 3. FLAG DR FENCE CLEARING LIMITS. 4. INSTALL CATCH BASIN PRDTEC71ON IF REQUIRED. 5. GRADE AND INSTALL CONSTRUCTION ENTRANCE(S). 6. INSTALL PERIMETER PROTECTION (SILT FENCE, BRUSH BARRIER, ETC.). 7. CONSTRUCT SEDIMENT PONDS AND TRAPS. 6. GRADE AND STABILIZE CONSTRUCTION ROADS. 9. CONSTRUCT SURFACE WATER CONTROLS (INTERCEPTOR DIKES, PIPE SLOPE DRAINS, ETC.) SIMULTANEOUSLY PATH CLEARING AND GRADING FOR PROJECT DEVELOPMENT. 1D. MAINTAIN EROSION CONTROL MEASURES IN ACCORDANCE WITH APPENDIX D OF THE SURFACE WATER DESIGN MANUAL AND MANUFACTURER'S RECOMMENDATIONS. 11. RELOCATE EROSIDN CONTROL MEASURES DR INSTALL NEW MEASURES SO THAT AS SITE CONDITIONS CHANGE THE EROSION AND SEDIMENT CONTROL IS ALWAYS IN ACCORDANCE PATH THE CITYS EROSION AND SEDIMENT CONTROL STANDARDS. 12. COVER ALL AREAS THAT VALL BE UNWORKED FOR MORE THAN SEVEN DAYS DURING THE DRY SEASON OR TWO DAYS DURING THE WET SEASON WITH STRAW, WOOD FIBER MULCH, COMPOST, PLASTIC SHEETING DR EQUIVALENT. 13. STABILIZE ALL AREAS THAT REACH FINAL GRADE WITHIN SEVEN DAYS. 14. SEED DR SOD ANY AREAS TO REMAIN UNWORKED FOR MORE THAN 3D DAYS 15. UPON COMPLE71DN OF THE PROJECT, ALL DISTURBED AREAS MUST BE STABILIZED AND BMPS REMOVED IF APPROPRIATE BY: BY: BY: PUBLIC WORKS DEPARTMENT CHECK DAMS SPACING AND CROSS SECTIONS �• PI,Ati - 217.40 )LARCH 2O08 IFFIN 1•-20' as ,�- CITY OF RENTON Plonning/Building/Public Works Cept.T MPORARY PPE' RSWI' ppER auc AOOOCIISY R-391007 APPROVED FOR CONSTRUCTION SUBJECT TO ERRORS AND OMISSIONS DATE: DATE: DATE: DATE: GRANT PLACE TOWNHOMES EROSION AND SEDIMENT CONTROL NOTES AND 201B-12- LO Do Do CD O LO Q n J O (00 i U) W 0 >z 0 H W U Q W 1- z Storm Water Pollution Prevention Plan for Construction Activities NPDES STORM WATER PERMIT, AND STATE WATER QUALITY STANDARDS This project will disturbed more than 1 acres of land, NPDES Storm water permit is required. Enhanced Basic water quality treatment is required per King County Stormwater Management Manual which meets the requirements of State water quality standards. Pacific Engineering Design, LLC. STATE OF WASHINGTON DEPARTMENT OF ECOLOGY PO Box 47600 • Olympia, WA 98504-7600 • 360-407-6000 711 for Washington Relay Service • Persons with a speech disability can call 877-833-6341 February 7, 2017 Satwant Singh Apex Enterpises Group LLC 5218 70 Avenue Ct. W University Place, WA 98467-4586 RE: Coverage under the Construction Stormwater General Permit Permit number: Site Name: Location: Disturbed Acres: Dear Satwant Singh: WAR304993 Grant Avenue Townhomes 1600 Grant Ave. S Renton, WA County: King 1.77 The Washington State Department of Ecology (Ecology) received your Notice of Intent for coverage under Ecology's Construction Stormwater General Permit (permit), This is your permit coverage letter. Your permit coverage is effective on February 6, 2017. Please retain this permit coverage letter with your permit (enclosed), stormwater pollution prevention plan (SWPPP), and site log book, These materials are the official record of permit coverage for your site. Please take time to read the entire permit and contact Ecology if you have any questions. Appeal Process You have a right to appeal coverage under the general permit to the Pollution Control Hearing Board (PCHB) within 30 days of the date of receipt of this letter. This appeal is limited to the general permit's applicability or non -applicability to a specific discharger. The appeal process is governed by chapter 43.21B RCW and chapter 371-08 WAC. "Date of receipt" is defined in RCW 43.21B.001(2). To appeal, you must do the following within 30 days of the date of receipt of this letter: • File your appeal and a copy of the permit cover page with the PCHB (see addresses below). Filing means actual receipt by the PCHB during regular business hours. • Serve a copy of your appeal and the permit cover page on Ecology in paper form - by mail or in person (see addresses below). E-mail is not accepted. You must also comply with other applicable requirements in chapter 43.21 B RCW and chapter 371-08 WAC. ;8 10 Satwant Singh February 7, 2017 Page 2 Address and Location Information: Street Addresses: Department of Ecology Attn: Appeals Processing Desk 300 Desmond Drive SE Lacey, WA 98503 Pollution Control Hearings Board (PCHB) I I l I Israel Road SW, Suite 301 Tumwater, WA 98501 Mailing Addresses: Department of Ecology Attn: Appeals Processing Desk PO Box 47608 Olympia, WA 98504-7608 Pollution Control Hear4s Board PO Box 40903 Olympia, WA 98504-0903 Electronic Discharge Monitoring Reports (WQWebDMR) This permit requires that Permittees submit monthly discharge monitoring reports (DMRs) electronically using Ecology's secure online system, WQWebDMR. To sign up for WQWebDMR go to: www.ecy.wa.gov/programs/wq/permits/paris/webdmr.httni. If you have questions; contact the portal staff at (360) 407-7097 (Olympia area), or (800) 633-6193/option 3, or email WQWebPortal@ecy.wa.gov. Ecology Field Inspector Assistance If you have questions regarding stormwater management at your construction site, please contact Greg Stegman of Ecology's Northwest Regional Office in Bellevue at greg.stegmati@ecy.wa.gov or (425) 649-7019. Questions or Additional Information Ecology is committed to providing assistance. Please review our web page at: www.ecy.wa.gov/programs/wq/stonnwater/construction. If you have questions about the construction stormwater general permit, please contact RaChelle Stane at rcla461 @ecy.wa.gov or (360) 407-6556. Sincerely, Bill Moore, P.E., Manager Program Development Services Section Water Quality Program Enclosure Storm Water Pollution Prevention Plan for Construction Activities STANDARDS AND SPECIFICATIONS FOR SELECTED BMPs Referance the 2005 WSDOE Manual for the following BMPs 1. Mark project clearing limits BMP C101: Preserving Natural Vegetation BMP C 103: Plastic or Metal Fence BMP C104: Stake and Wire Fence BMP C233: Silt Fence 2. Establishing the construction entrance(s) BMP C105: Stabilized Construction Entrance BMP C106: Wheel Wash BMP C 107: Construction Road/Parking Area Stabilization 3. Storm water detention Onsite Detention/wet vault to provide Level 2 (forest existing condition) Flow control 4. Selection and installation of sediment controls BMP C200: Interceptor dike and swale BMP C207: Check dams BMP C233: Silt fence BMP C241: Temporary sediment pond BMP C250: Construction Storm water Chemical Treatment 5. Soil stabilization BMP C120: Temporary and permanent seeding BMP C 121: Mulching BMP C 123: Plastic Covering BMP C107: Construction Road/Parking Area Stabilization 6. Slope protection BMP C120: Temporary and Permanent Seeding BMP C121: Mulching BMP C130: Surface Roughening BMP C131: Gradient Terraces Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities BMP C200: Interceptor dike and swale BMP C204: Pipe Slope Drains BMP C207: Check dams 7. Drain inlet protection BMP C220: Storm Drain Inlet Protection 8. Storm water outlet protection BMP C220: Storm Drain Inlet Protection Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities APPENDIX C MATERIAL SAFETY DATA SHEETS Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities Emergency Phone Numbers Fire, Police, Ambulance 911 Owner: Ethiopian Muslim Association of Seattle (206) 420-2940 General Contractor Office: Site Mobile # Subcontractors Sub #1) Office: Sub #2 Sub #3 Sub #4 City or County Contact Spill Hotline: (206) 973-4770 King County 24-hour dispatch: (206) 296-8100 Washington State Ecology Dept. (360) 407-6000 (Olympia) (425) 649-7000 (Bellevue) Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities Spill Report Form LOCATION: II I (Date: Time: II Regulatory agencies notified (date, time, person, agency, and how): Material spilled: Quantity Source: Extent of injuries (if Adverse environmental impact (if Immediate remedial actions taken at time of spill: Measures taken or planned to prevent recurrence: Additional This report prepared by: (Signature) Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities Storm water Monitoring Form PROJECT: CONTRACTOR: RECEIVING WATER: MONITOR PERFORMED BY: Monitoring date: Time: Current weather conditions: Previous 24-hour weather conditions: 11 SAMPLING POINT I TURBIDITY (NTU) 11 Up -Stream Adjacent Downstream Comments: Sampler's Signature: signature print name Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities Table 1 BMP Maintenance and Inspection Schedule (Source Control BMPs) The Development Company Anywhere, USA BMP BMP Name Recommended Maintenance Recommended Designation Schedule of Maintenance C101 Preserving Inspect flagged areas to make sure flagging Daily Natural has not been removed. If tree roots have been Vegetation exposed or injured, recover and/or seal them. C102 Buffer Zones Inspect the area frequently to make sure Daily flagging remains in place and the area remains undisturbed. C 103 Plastic or If the fence has been damaged or visibility Daily Metal Fence reduced, it shall be repaired or replaced immediately and visibility restored. C104 Stake and If the fence has been damaged or visibility Daily Wire Fence reduced, it shall be repaired or replaced immediately and visibility restored. C105 Stabilized Quarry spalls (or hog fuel) shall be added if Daily Construction the pad is no longer in accordance with the Entrance and specifications. If the rock (or hog fuel) Tire Wash entrance is not working to keep streets clean, then install wheel wash, sweep streets, or wash streets if wash water can be collected. C106 Wheel Wash Wheel wash water shall not be discharged into Daily a storm drain or the site's storm water collection system. Use closed -loop recirculation, land application, or discharge to sanitary sewer (by permit). C107 Const. Road Inspect stabilized areas regularly, especially Daily Stabilization after large storm events. Add rock (hog fuel), gravel, etc. as needed to maintain a stable surface which won't erode. C120 Temporary & Re -seed areas failing to establish 80% cover Inspect to ensure growth Permanent within one month (during growing season). If weekly Seeding re -seeding is ineffective, use sodding or nets/blankets. Eroded areas shall be corrected, re -planted, and irrigated as required. C121 Mulching Maintain specified thickness of mulch cover. Weekly and following Eroded areas must be corrected and re- storms mulched. Drainage problems must be corrected. Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities BMP BMP Name Recommended Maintenance Recommended Designation Schedule of Maintenance C122 Nets and Inspect to ensure good contact with ground Weekly and following Blankets and no erosion of soils. Replace damaged storms material and re -staple where required. Correct erosion problems immediately. C123 Plastic Replace torn sheets and repair open seams. Weekly Covering Replace deteriorated plastic sheets. Dispose of plastic when no longer needed. C124 Sodding If sod is unhealthy correct problem. If sod Weekly and following can't be established seed area and use net or storms blanket to stabilize soils. C125 Top Soiling Inspect stockpiles regularly, especially after Weekly and following large storm events. Stabilize areas that have storms eroded. C126 Polyacrylami Reapply PAM to actively worked soils at 48- Daily de hr. intervals not to exceed 7 application per Application month. Reapply PAM to undisturbed soils at 2-month intervals. C130 Surface Seed roughened surfaces as soon as possible. Weekly and following Roughening Re -grade and re -seed any areas beginning to storms erode. C131 Gradient Maintenance should be performed as needed. Annually and following Terraces large storm events C140 Dust Control Re -apply dust control measures as necessary to Daily during dry keep dust to a minimum. weather Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities Table 2 BMP Maintenance and Inspection Schedule (Runoff, Conveyance, and Treatment BMPs) The Development Company Anywhere, USA BMP BMP Name Recommended Maintenance Recommended Designation Schedule of Maintenance C200 Interceptor Inspect to insure structural integrity. Repair Weekly and following Dike & Swale as needed storms C201 Grass -Lined During growth period, inspect grass after Weekly and following Channels rainstorms. Remove accumulated sediments. storms Inspect outlets to prevent scouring and erosion. C202 Riprap Inspect to ensure underlain soils are not Weekly and following Channel eroding. Inspect for slippage on slopes. storms Lining C204 Pipe Slope Check inlets for undercutting and outlets for Weekly and following Drains erosion after rainstorms. Inspect pipe for storms damage. Check pipe for clogging debris. C205 Subsurface Check to ensure drains are not clogged with Monthly Drains sediment or plant roots. Prevent heavy truck traffic from crushing piping. C206 Level Spreader Check to ensure proper functioning after Weekly and following rainstorms. Prevent traffic from crossing the storms spreader. Repair if damaged. C207 Check Dams Remove sediment when one half the sump Weekly and following depth. Check for erosion around edges of storms dams. C209 Outlet Inspect and repair as needed. Add rock as Weekly and following Protection needed. Clean energy dissipator if sediment storms builds up. C220 Storm Drain Replace clogged filter fabric. Clean sediment Weekly and following Inlet from stone filters. Do not wash collected storms Protection sediments into storm drains — remove to soil stockpile. C230 Straw Bale Inspect daily during rainy periods. Check for Daily during prolonged Barrier undercutting, end runs, and damaged bales. rainy periods. Remove accumulated sediment when one half the barrier height. C231 Brush Barrier Inspect daily during rainy periods. Check for Weekly and following undercutting, end runs, and damaged sections. storms Remove accumulated sediment. Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities BMP BMP Name Recommended Maintenance Recommended Designation Schedule of Maintenance C233 Silt Fence Repair damaged fencing immediately. Weekly and following Intercept concentrated flows and reroute. storms Remove sediment accumulations at 6-inches. Replace deteriorated fencing material. Properly dispose of used fencing. C234 Vegetated Re -seed damaged areas immediately. Install Weekly and following Strip sod to replace eroded vegetation. Reroute storms concentrated flows through vegetated strip C240 Sediment Trap Remove sediment when it reaches a depth of Weekly and following one foot. Repair damage to trap storms embankments and slopes. C241 Sediment Pond Remove sediment when it reaches a depth of Weekly and following one foot. Repair damage to pond storms embankments and slopes. C250 Storm water See Monitoring in Section 11 As required Chemical Treatment Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities Erosion and Sediment Control Inspection Form Erosion Prevention Inspector(s): Site Name and Location: Date: Current Weather Conditions: Last 24 Hours: BMP Designation O.K Not O.K. BMP Condition, Corrective Action, General Notes Construction Access Trackout? Street Clean? Soil Stabilization Signs of Erosion: Gullies? Slope Failures? Rills? Slope Protection Plastic Condition? Grass Growing? Hydroseed Condition? Matting? Perimeter Control Clearing Limits Marked? Silt Fences? Swales? Conveyances Stable Ditches? Check Dams Intact? Sand Bags? Slope Drains? TESC Management Revisions Required? Water Management Infiltration System? lean and Dirty Water Separated Offsite Water Bypassing? Outlet Protection Stabilized? Pacific Engineering Design, LLC. Storm Water Pollution Prevention Plan for Construction Activities Erosion and Sediment Control Inspection Form Sediment Control BMP Designation O.K Not O.K. BMP Condition, Corrective Action, General Notes Storm water Detention And Monitoring BMP Maintenance Inlet Protection Dust Control Spill Prevention ondition of Discharge Water Comments: Pacific Engineering Design, LLC. IX. Bond Quantities, Facility Summaries and Declaration of Covenant 52 0 LL O F 4 Ln Lr0 V GC Z W W 2 2� r� a V Z m AQ 1 O M N 00 rn Sl L_ O 0 1� W ice1 1Lo^ _I 0 H C 0 .y d ar C v O N Q O Qi .O Q c 4 O Y Q) u Y aL+ a) i°.+ °o c O p aJ L u 3 L O « 4 L 0 O O v Y O O O O c c V L 0 3 o 3 s m c `l 4 `l > ar ar � ar v al Y al CX Y 0 O L Q L C O O C Y O Q ` Q V Y L m O O o 0 Q) p a/ Q. 3 c 0 c Y 0 o O m O� m i.+ Y c Y w � am- � .fl WE c v � Y O E c E ai .t al a' o° a Y O m O =1 Q O u Y Qc a° °� y 0 o u E of oc u a (Ca c E o d Q)•C C O u OC ,0 L O C O C C M O O E- O U h N u m 3 ar O Cf O ..0 L O m `0 C o c o 0 o c +" u u aiLl cn cn c O u ar N Y � � • a Y c O Y � o � C v L ar — � Y .0 Y C C al al Y bA C Cv G � L 7 V d E O C GG Y =3 Y u O 0 z LL ac C LL=3p Z O p E 3 ti m O W m m C m LL p O a) 4- Y_ u C .YC U v Oa .c O 1- v m M m 4 C ar m O p c O Q W =� 7 C u O Y u +� O Lu '� c M u Q ar O c c c m W o 4 C ar O E C • • ac C (La al N W W ar E vi 'O c O LL - � •m u � .N d L W u w e E al W '� al O aO O. + c= 3 v m 3 v = 'a N O E J 'C E, C 'O m e LO a o O s c N m >•. d aF al '0 'C m W C m v4. m v z ar O O L c M ar ar O. ar -� Y t 4 0 a1 0. ar ar u O '' Q w t . c Z h m N d 'O T y O Z Lu a) C C O} Z O l7 O O Y m t u •o E c N z c W Q i^ z � Y� 3 E =3 Q Y w j Q >> n O y O O m -0 u -O al u C al .y E C tiA p C_ C C C C C Y - > u Y CL C al O O O O O Y Y Y Y Y m p 4m• L L m u 3 Lan) Lan) Lan) � � Q ar m aEi w t ar c ar 3 E Y Y E L •'- O c Y m 3 ar > L a n n O E a C7 ar O E Y o o c° u Z {- O. tio C v n E O u E a, C .y .3 u u ami 0 �T 0 0 0 o N N N V t�D N c-I N c-I w V Cl) O O a N O C C m a, d D N z O G O N z c cr ci = ma o �_ ao�a w �v a� r 4 W W Y Cc O O Z QQ �= G V O Cc C, 0 z LL m V W Z O W Cc w �- O Cc a W h N tU o r 0 0 U w d M N C1' Ln CJ 40 rn cr- v i a a 2 ko I T� V a C� 0 N CJ H C C a 'a O 0- Q1 a c a Z Z L!J L!J o: o: Q O LL LL O O L a o c o v n o ++ OL U U d ai 3 a' 0 c -a .O Q' C 00 tN 00 a N c > 00 d1 CL ? Ln .. O c ti"',I m -a Q d a m` +, Ln I c a 0 ru 3 m Ln d } +� "' a` m o LLnn ai Ln N c-i IN ;. a a a ai ai ai a v = 0 0 3 L L p a s a u L N u ai ai u u C N L L aO O N i d i Ln u N N N L }� N O L L o O a a O 3 d d Q Q n. Q Vn G1 �C G 00 o 00 � +' N 00 w Q 'o � O C a0 N *' c -0 •U N = C O N m 'A E v O to E O w m Ln L ai c V O u V c N O O"0 U� o \ ++ N CL fl_ ai > M O j u C m Z m O ai Q o c H Q ai i% N _ a (� Q 0 u to Ln c N Ln o O D C w CL w Ln CaJ u 0000 L ++ c rn a. •� o Qm u Ln ai o J a., OO 00 CD +' o Ln y c N °�° 4= v o- c f 6 0 v N m N u to s a O o y C O j rN r-I N O (D r-I c-I c-I t u ` a m m DO a C y z.. .. 00 io '6 O ai u tw Z .a N J in ru ai E ai++ 'm in L .. O c •O C � O` .Ln ru-a Z B Q z +, = -p C xx > n Oq o a N O Z Q N — u d aj �. � Q a'' O N •C c '�• Z vl C O •� N 'p v N L1 " L -O in N } Z d LL LL d w d U U N Ln d Q u v t 0 3 CL i W ui O F- Z Q a im m F- Z ui G W O oc Ca G W f" 7A J O oc Z 0 F- Z W 0 ui A 06 Z O O/�/ oc W oc O LL Ln n O O to E a) a 00 00 000 ooln 00 00 O O 00 00 O O 00 00 O 0 fV Tr O 000 O OC O O O 4 O O O O O O Vf O 00 O N +' n -1 tD �-1 N N Vf N N I� 00 M y U N Tr N n r4 M N 14 (6J Q 0 00 rn 00 00 IH rH U') N 0o 00 � m o o m 00 N N r�-I Ol �--1 '� .� O f6 G m cr u u u LL LL >- Ln U } Ln LL >- Ln LL _1 >- Ln >- N LL J LL J LL J >- Ln >>-- CJ U U U LL J LL J >- Ln >- to >- NM Q W W -1 _1 1N _1 W W W O O O O O O O O O O O O O to O O O O O O O O O O O O O O O O O to O� O O O U1 ��� 00 O� n� O O O O O O O O O O O O O O O O . l0 O to to Ol N r-I r-I N O O r-I m rl N N N V 00 CF to O O O Ol O r-I W O O O W m Ol r" r" r" 000 `� n OO N N rH rrH r-I' M' N' + u = u E L M `. 1 d' N M `. " " " a V) V) ' 1p � M N N N N N `~ �f Izf V1 V1 V1 N N N u I�f zf H i a a a a a a a u G V) Vcc1 (Ij Vj L4 Lli VVc) VVc) Ln Ln VVc) V) VVc) V) V) y Cf- ut � ut ut ut � � ut � ut ut � ut ut ut ut ut 0 rl N M Tr Ln w N 00 Q1 0 rl N M Tr to w N 00 Q1 0 rl O N N M Vf 1? N. 00 Q1 M M M M M M M M M M N N N N N N N N N N M M Z Ln U U U U U U U U U Ln Ln Ln Ln Ln Ln Ln Ln Ln Ln Ln U U U U U U U U U Ln h h h h h h h 1n h h h h h h h h h h h h h h h h h h h h h h h W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W C O t E b°J0 r+ x bD x Ln > v 0 0 Ln r+ x 3 p E Y n� 6 a) X 0 o 0 ' 6 c +� O_ m � C N U _ N - vl Q- O Ln O1 r1 O1 _>• Q E Q- U O � O Y E - - N Y' U U U E O) O bD N UO CY 0) _ ('rl to W r-I i i Q Q w O E O� z Q U U U f6 W W L .O_ O OC to •E a) bCD i V Q N C i i i W 0) p p in t U SZ SZ W Q_ E O Y 7 N O f6 f�- b0 N O) -� C L f6 O f0 O 2 O bU C t V � C by C 0) O) i O 7 o n N LL_ In t E .E U 6 i iL 6 6 •- Z E E .- 0 E E E> co)-' `n -1 r 1 v U °� m U b0 ° i°1 X N a) Q Q Q Q :' °' U Q O O + + N bD bD bDCL In T W Y t L C> t m Ol Ol 07 �' m O U to z� U V b'D b'0 b0 U +� 1b w u U C 16 C 16 _C '6 to Y U V O) U v� U C U C O O) >,'6 M > O) +' a)> O) 7 7 C •Q C Q C Q Q Y U O Y U O -6 O) '6 O) '6 O) O) O) -6 O '6 O U to Lu y0, t0 m U U U Q W LPL LPL 0 m_=� J c G c c n. n. n. n. w w w In Ln Ln In In to If r1 r1 r1 0 Ln 1n Tr 1n a) o 0 0 ci �Na tD 00mo NNMQ v v O @ N -O N a` n > 7n O z O UI Z O Ln O w W F- W TW i Y 0 N Z a cr 0 Z 0 m Z W 2 W 0 CL 2 W F- 7A {A Z CW G W 0 CL 2 W F- a F- W �W/ W N 0 LL 0 V- 40 ,_ O N 'u E O U a) m ai m c c O a m C: 0 0 0 0 0 0 o 00 o o rn o Ln N .� o n rn o ao N N It M It N E U0 0000 al o O Cc C c-I O c-1 00 0 O ^ ci 0 !O N N M u N O U E CL al > � O +' OLi LL ru r N ru t U c �- Nom �_ Lu cc 0 } } } U U } } LL LL LL U } } } } } } } } U U } } K } } >-LL LL LL W U U 1n u U U J J J W U U U 1n In 1n 1n In W W In Q U 2:1n 1n 1n J 1n 1n Q W W CL N O O O��t O O O O a-1 O O O O O O O O O O O O O O O O O O O O O O O 2 o 0 o r-. M. o 0 0 o cn o 0 0 0 0 0 0 o V 1 0 0 0 0 0 o in o 0 0 0 0 0 0 .- l0 m a--1 O N O N to O 000 O m rl m m O O N N O rl 000 O 000 00 m N Vl 1n 1n J N N M N O N N M l0 Ol N N ci to a--1 Q CL V O 00 0 0 D m V)k Q)- vlinlv'� V%, Q� Q)- in, Q)- V) Q)- V. V%l .—..I 1n O ci 00 Ol 0 ci N M 'T 1n m t� 00 m 0 c-I N M l0 t� 00 Ol c-I c-I c� c? cd cp cd c� c� 0 N tLo C al t t t YN } N > 'O f0 - Nc Nc Nc _C C O i 'O O ,dj UO j, i O CL C C C i O.. -0 C (a p 1a p al al al on N pq on L LL' Up 1i CL c > o 0 o °° O 0 0 '-' O p 'O U U U i U Y Y Y O -u U vYi in t L O p p 0D N 00 ++ m Q. E 3 p u N O O W fa fa C m j O C C: Y l0 C - C - C - u � 0D � v� � N N N > a_'' J to O.. 06 O �1 ai ai i E > ..C] I- f0 C C U U U ai -O ai -O ai -O M ++ Q o U O U x v= p p o al .O o' L o' L o L 0 O.. 0 O.. 10 O.. --- N 00 l0 ai Q a 06 06 N \ O O u u u u E E E -1 c-I M T- V- C N ci d 0L0 } O p u O N Y u uC m 43 c ti4 ti4 ti4 ti4 O O o c c c 1 do al > a .- — U- -- += v O W v= = N o C C C u u u O O O O O � .+' O N> O U V V Z Y N a > > > > U U _C U U 02{ 06 02S .Q ..Q ..Q O -O C N -O -O N�—=— S3. '� '� O -- W u u O O u u C C C C-- f0 fi fa p C O fa fa C'J fa m fa m U m m U X W X W LL lL lL LL LL LL LL Vr Vr (� CJ Vr c al N O N � N � N O 0 0 O o r4 t0 N a rn 0 -3 c °i o c z 0 a m 0 a N Z a 0: cr a � --I m o :IF a 0 00 txo m K W W N Y O Z a Cf 0 O m Z W S G W O cc a 2 W N N N N Z CW G W cc a 2 W N a Q W W N O M U O E u v ai W v cr *+ -6 c c a O d � 3 d C E 0 O U (U o n E c m 3 d 0 0 0 0 N O O N „ ,-I O m ct -0 a) O u m-i N w0000 ' E a > ar O +� Q U-E O O Ul)O O O ci N 10101 d 0 0 0 0 o 00 o T Ln n ca b U ct N O tom WC w O O 0 LnLn } to } to } to } to U- J U-LL .J J LL J U- .J LL J LL J LL J LL .J LL .J } to } to } Ln } (n } to U U m LL to LL _I >- (n >- to >- to >- (n >- (n >- Ln >- Ln >- Ln >- (n >-U- (n —I Q D Wm W d N O O O O O O O O O O O Ln O O O O O O O O O O O O O O O O O O O O O O m U O O O O O O O m 0 to 0 00 O O O O O O O O O O Lr1 W O O O O O O O O O t0 H .— 0 w0 to wO r, 00 to n ri m N to w N ri 0 to I, m 0 m d' w w ri to I, w to O w J m ci r-I m In m r-I r-I r-I r-I m m ZT ZT 00 r-I r-I N N -zT m m ci ci Q O c m N Z or Nmd " nLOl�oorno 00 - Nmv n�noorn0r Nmv O ci N f�1 N l0 n 00 61 ri ri ri ri ri ri ri ri N N N N N N N N N N f�1 m m m m Z�ofofofof �������EEEE ofofofof LL D CA Z0 W T O O T o vi O n° O Q n° O Q Y > to 00 N 00 } Vn W O 0 N 0' 0 0 Q 3 >- to to N >- to L!1 N 0 0 0 0 0 b0 O O L to to a O O C O> !n O> !n O N L O a V C to S +� != L U U N > O N > O 0 aJ Q I"' C C w C a)O C a) O O L O aJ C fa `C +' T +' v to N > O U Z L WC U U U E O Y Q ri Y +� +� �. N 6 i LL V LL V ca i Q G E E E O f�a �, i� E 'y� !`I _ !n Y' Y' Y' Y Q IL CS N N Q - aJ LO ..0 ri _ !V O O O O- v u `W / -6 -6 -6 O �. — o> t aJ Q� vl O _� m Y Y' Y Y' _ p_ �'' L T O T _ _ _ _ L!1 O O p 3 3 3 M U u u u u O aui v —° v v zo Zo v- - ai d' O O_ L L y� fa f0 > L N L N L N L N Q +� VI E 4- - L(1 a) aJ -� -� -� -� -� d' d' by C bOA bOA bA 1— a) 3 3 Z O_ C Q m- bU � � - L!1 - In U aJ aJ aJ - N N N W > _ 3 3 L O v� to CL L 0 '6 C '6 C 0 C O E -6 m K (7 (D X a) X a) to U C -6 to to to to = b0 bq b0 O N N O O 0_ O 0_ O W O W K Q lJ 6 l7 W- fa 'L � 02s n� 02s to n o o u u o 3 a3i ar a3i aa) c' r-I Q r-I Q w Q Q Q Q Q>> Y u U U U U to 3 3 3 3 3 3 L -6 -6 -6 -6 b0 .� .fl .fl %� � '6 2 2 � 2 2 m 2 cc Q Q Q Q CO C7 CJ C.J C.J C.J C.J to to to to N to to to m to to to to to to Q 2 2 2 2 2 2 2 l7 C7 �— s v m a, u 0- c Cf c} � A � w O O m lA i al Uo m N m w _ W h 0 z cc ui 0 N m F z ia5a ui G W ui CC 0 N Sa 0 L W F— N Ln a a Q Q t0 i, E `a a Q W U O O Y N E v O O U N - w v Y Y 0 C C 0 O cf v V �M V C a� E Y 0 O U d O c♦Z C — Y C �(r V u N C a) O E O U a j v a) O Y Q LL E C T +' N 0 c c: U n O m X i W bn K a r Ln��� r r r Y c: O O O O O O O O O CJ . i W Ln Y c J J J 0 0.-+Nmv z Z o n a J a N O 0 N3 O >`- " N 0 O II ^^ V N C oZ Ln QUo6 r`i - Q in Y O o6 N o_N Y W Q (A O u O (j O a) O 1 In -0 O O0 Y N w o Y Q Q Q t In CLNNIZTr-i -1HH 0 0 0 N N N W W W W vtD N HtD N c1 \ \ \ 0) 0 0 -o N O C 0 � d CL > C N V d C! OR OD •E 00 Ln m OD 1 _ rl 00 w I H H H H q Ln Ln Ln N 1l d Oai m (J (J (J 00 00 (J m Z O C7 C7cm C7 C7 C7 C7 C7 cm LC �• �• r-4 LD m Ci �• d m m m � �"� m Ln eNi of H O_ b tn l7< Z O l7 Z Ln J \ Q F ~O Q W Q W = w !Z� F- z to Z) O O J w Ln F- Z Ln O W O 025 W kn O J O .--I U U- >� Z J W > W Q Q Z J Ln z in a 4 > a ccQ OF-- O ci N m qT In .--I N M 0 = a W J Z Q J Q J Q J Q J Z Z K F- K F- K F- K F- Ln ca 0 O J Ln F ',.... Ln CA a Ln O W m Q w W Ln Z W F O Ln L F 0% Y W 0 p U' tw UL °- c 3 W c f1 Z o O •G W � Xk N C Cl to c U' v Oc G Z U J M N J G `W H G Q to O C T f0 -O C ��(_ W Ln y m _ m i Z O m p U N v J> > J C: CC _ N~ C _ LL _ J in Ln W v o� N Z N f0 Lp �.{� Y LJ LJ F' d Q� G > r M C_ C 0 N (a ', O E U c� cr c O m m c � m cr C O U - mCl E v > > o moo" CL E c v o 0 0 0 o c > M V y, 'O O M C O 00 O c 0 W ` N N r-i lG lG U > " v a, O n m E m Q e > � 3 m U > p m v u X = a 0 � d C: ` m v CI Q w t t t s s s s C 8 N !a m m m m i.L (a l~l. (6 LL R l~l f0 F iL (a (6 (a (6 (a m m t+ W W W W W W W W W W W W W W W W j N 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 j = 1� O O O O Cl O O O O O O O O Cl O O O O O O O O O O O O O O O O O O O LO O O O O O O O N O 0 0 0 0 N O O O O O O O O M N M N �-i w w O m m J W N M O O N O W O M O O O N O N N� j W N N i, O �--I c-I c-I N M V N i, M ci N Q d V N M V N V o0 w C w O m M V V N r-1 c-1 c rl c-I N N N L 0 N O O M V N tO I, 00 a, O �--� N M V N w i" w m O 1-1N M W 00 Mci c-I c-I c-I c-I c-I c-I c-I c-I c-I N N N N N N N N N N M M M M Z N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O Z v 'a v t v 0 a C- > > > > > v C a>'i E O O O O O in p f0 t t L y .0 L R u fV V v= C R m m !a m- _ Lo C _ _ - fN in 00 V o Lo- 00 oc C= C= C= C= C Cr"i N 00 �--� U U U `i `i `i N M M W -O -Q Oct) O N O L O^ O� O c-I c-I N>>> U U U U U tJ U U tJ d d O V V J= i= = 'a 'am V Vm Vm yy, y,0- 0- 0- 0- 0- 0- d 0- d U' U>cr ZoC ai ai 'am m !Va >> n v > O O O CO O O_ OO_ 2 a[ aaa >m >>> > > > > > > 0 a a UUUUUU UU H UUUUUU 00 Q to W N = W N r Y J CC O v LL � cc H Q Q V y� O Z N MO W Z a W (WLJ / ` V Z a °C G � W 0 H N C_ c O � o '� O E u U _ a c c O D m C m D Cf Y c 0l Y 0 O U YE L O Q E Y c Cf O 00 00 O u Y +' n N c ^ N to 00 E U a, > � o Y Q ILJ C D O to o U c •'' O m X Y L Ll b_4 K C f0 Cf u- J u- J u- J u- J u- J u- J LL. J LL. J LL. J u- J u- J u- J u- J u- J u- J u- J u- J u- J LL. J LL. J LL J LL J LL J LL J LL J LL J LL J LL, J LL. J LL. J LL. J LL. J LL. J LL. J LL J C 111 Q a m 0 0 0 0 0 0 0 0 0 o O O O o o O o O O O O o O o O O o O o O o o O o O = � o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 o F U Ln ci l0 o0 o O O O N 00 00 00 o0 Ln O Ln Ln t*kO t* Ln c-1 t0 00 O O N 't tO oO O N tt tO 00 J ' M 4 Vl I- M Ql Ih Vl ' i CY Ih Ct Ih N Vl Ih O r-I r-I N M Ct Vl Ih M t0 Ih 00 Ql O N M 4 Vl kD Q C � � m V? V, V, VT VT VT VT VT VT VT VT VT VT VT VT VT VT VT VT VT VT VT VT t/T VT VT VT VT VT VT VT VT VT t/T :Ln:) tf Ln t0 N W M O H N M tt M W N oO Ol O r-I N M d' Ln t0 N o0 Q1 O H N M ' t M W Ih W o m m m m m Z o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 c O G1 N Ln 00 t* O tO tO oO r-I -=---- r-I r-I N M M uVi C = N-I � - - V Vl OO 't O LO oO O N 00 Y Y r-I Y r-I Y NM Y Y M Y d' Y t* Y {1 {1 Q- {1 cL S1 La- O- - t0 - W N Ln OO t* O lO OO t* W ci d c-I d N d M d M d d' d t0 d h d d u d u d u v u d u d u d u 0) `u d u F F F F F F F F LL, w' ui L L u.i Lu u.i u i u.i V' o 0 0 0 0 0 0 0 o a a a a a a a a u u u u u u u u u u Q U U U U U U U U U Uy Uy U Uy U Uy U U U U U U U Uy Uy U J J J J J J J J J I > D > > 22 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > v u u u u u u_3 u u u u u u u u u u u u u u u u u u u u u v v u u u u c LLJ a z cc 0 u z F0 V r W W (A = W N � Y J_ O V LL � cc H W H Q Q V o OL Z O N CO r Z Z Q W ,Wn / ` V Z a °G G Oc W 0 H N tw C O O N m V O E O V N - w 0) —> of _ -O c 0 O m ra Cf C O EV N O j N O O C td 7 Cf V F t - C N N O �E V m > V O a Li E c 0 oA O V c O m XV L tjO K Cf LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL LL I.0 J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J J Q I tN O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O = N O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O V O N N N ct tD 00 c-1 tD I-i tD c-1 tD c-1 ct m Ln O tD c-1 m wN m Ln c-1 ct wm N Ln 00 O M wm �-i J CO ct ct n O M N n M w ct m Ln 00 00 m 00 1-1 1-1 LA L!1 N M M ct ww O N Ln n m N d' woO I-i Q N N M M ct ct Ln I-i 1-1 1-4 1-1 c-, N M ct Ln c-1 c-1 c-1 c-t c-t N N N N M u C {- � m t4 t4 t4 t4 t4 t4 t4 V). t4 t4 V)} V)} t/t t/t V)} V)} V)} V)} Z) Ln O c-t N M ct Ln tD Ol O ci N M ct Ln tD n 00 Ol O ci N M ct Ln lD n W al O c-1 N M ct L!1 tD n W m O O O O O O O O tD n n n n n n n n n n W W W W W W W W W W al al al al al al al al al al ci c-1 c-1 c-1 c-1 c-1 c-1 z O O 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Conoco 0 0 '6 o. y - - - - - - - - _ - - N V) 00 ct O tD 00 d' O N tD 00 O = N 0i 01 N 0i 0i N N N 0i 01 0i N V) 00 <}' O tD 00 <}' O N c 0) c 0) c (1) c (1) c 01 c 01 c 01 c 01 c (1) c 01 c (I) c 01 V 0 ^ tD 00 c-t c-t c-t N M M ct Ln tD rl ? -� >, W w LU W O_ W 4. W O_ LU 4. LU 4. LU 4. LU 4. LL! 4. LAI 4. LAI 4. LAI 4. LU O_ Q O a O a O a O a O a O a O a O a O a O a O >, a_ O tD - o0 N c-1 u) c-1 00 c-1 d' N O M tD M 00 d' d' Ln O lD N n C7 U U p p O O O O O O O O O Q O. O. O. O. a a a a a a Q z L 0 0 0 0 0 0 0 0 0 n 0 0 D 0 4 ' t tL u" � � u t + t avvvvvv�vvv�v�v Q Q Q Q D Q Q Q D vwvvvv�v�v�v >>>>>>>>>>>>>>QQQQQQQQQQQQ>>>>>>>>>>>> O V V V V V V V V V V V V V V a a a n. n. n. n. n. a n. a a V V V V V V V V V V V V m Cf �o CO v00 t v a o[ r W W cA = W O v LL � CC I— W I— ~ a a � c 0 O Z O N CO r Z Z a W rLU WV a Z CC °C W 0 H LM O O W E Gl a 0 W U to C � O N V E S O V 0! - w _ -0 Li cc O � m C R7 N:3 V O O O O a ut ut C a) o U N Ln N Ln E a o O a E — o � Ln o 1 =3 0 0 0 0 0 0 U t M M c o N N � E V a, > o +• a c Li N to V _om x+ c Ll on a >- L.L LL} V >- V V V >- V �_ } v) u J J V) W � W W W v W V1 w tz O o 0 0 0 0 0 0 0 0 0 0 O c� at o0 tD M O tD O O O N O vl O Z N N H 0� O v) Q O ci M N ci O N H H H H O a 0 1Nm� n D c� ci M V) tD I� 00 Ol ci c-I ci c-I c-I c-I c-I W Z O O O O O O O O O O O O O O O Vvj V1 V1 V) V) V) V1 V1 V1 V1 V) V1 V1 V) Ln V1 J F• 0 m v) a, Q c Q� Q O o tn m cL > Q H Q.- H H H � �$ 'oo u N � } O O O -O 00 -o O) p titL— U Q C tV 3 M to c v 'Q Q n m F- M N U1 O) cL O) O) V -o O) U 3 V) V) V) o 0 0> C ` c° .� p o 0 0 0 u Qo U x > °� ai Q t m c ai - o Q o o o o Ci m � O> x O> Q W c` Gi U o -O a ._ N ._ N ._ N�� -_ E E> Vi 0 O LL LL w (7 O O) O) O) O- tV w O) O) V Li 0 0 0 0 0 0 0 0 0 00 tD � 00 00 00 V Y C co E E 3 m U. 3 U U U U U U U U U U U U U U U U w ca W ca W ca W ca W ca W ca W ca W ca W ca W ca W ca W ca W ca W ca W ca W ca W F_ J L o o V Q 1 O O LL C o W Q O 00 N C 00 f6 O N N L +� i ci N M Vl l0 I� 0 0 Ol O ci H c N c M c c V) c to c 0 J O V LL L LL V) u- V) lL Vl LL Vl LL V) LL Vl U- Vl lL Vl lL V) U- Vl lL Vl LL V) LL V) U- V) lL Vl Q F. O co li Vt a� 3 v C ui t,L D N OG t V) W -O Y ±+ •D Y ±+ O) o C _O ++ ± -• V V V LL jO a O O O (D (D > F= tL +, > LL -p (V L ,,., ±• o C7 Eon t� Vl Vl a m ol tor,r, Ci 0 0 0 0 0 l\O a, O O -O v c w o cv C F— W W to = W_ N Y J GC O v LL E— W Q Q V 00 Z N Co in Z Q W LLI , v Z a °C �_ GC W 0 N ti0 c � 0 N m O u U � � w N `- T � C C m O m 3 G m � N O YE f > W > L O Q_ E Y c m v Y _ N O E U � v O Y Q. ' E m T N m GO0 U N O m x ti0 m Cf Y (n G W z uj u � O c-i N (M cY V1 coci N M V' V1 l0 n 00 Q1 ci ci ci c-i ci ci z a� m W N 10 V1 Z 0 c O c).. V `v Z O W N i Z i W N io n n 0 0 0 O O O V to N 14 \O V\ O\1 O O -O W .. .. N N O C N a O N u a �c � o O O O O O O O ut ut V1 N I� N ul I� G ul ul � Q LU Q m � O V O Ln Fa- i o n � W W J J tA LL � Z I: 3 o � a z a ] � w Q u u Z 7 a Q Q � v ] .c 0 T .0 cf a v o ° m v o0 m a � W W Y GC 0 Z Q V a Z 0 W Z W \W a W W Q 0 U. Ln = c O N '� O E U � � � w � 01 — T � = O N� V a+ = ai E N O U a+ m o d O Q _ m 00 O O O O O O 0 00 0A 000 N O 00 1 U '^ a.+ O 00 O O 00 1� = N n ll1 e-I 00 ei M 0l j tD N O 7 E ei D � u � o � Q E oo ci ci ci �i a 0 0 0 0 >, N O O 00 00 m V N V 0 W U N O m w oA Y C a+ � L L L I- I- L I-L L L J _ Q m W J J _J _J _J m W m W m W m W m W m W m W m W m W m W m W m W m W O O O O O O O O O O O O O O O O O O O O m 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 � .— O O l0 O O O O O O O O O O O O O O O O O Ln M w N 00 O O O O O O O O O O 000 K W O m N 00 O N O 00 O Ln O O O O �• N c-I ci d' N ci 00 Ol O O j O c-I N M d' V1 w Il 00 Ol ci N M d' Vl T I� O0 Ol ci ci ci ci ci ci ci ci ci ci � � U N N 01 E E O E E E m 01 E 01 E 01 E p " U U L U U = U -- — O N ate.+ ��+ U U U 00 m Ct l0 00 ci ci 01 01 C = C C O E N N N N N T E E m *7 ° o Q t11 Ln Ln Ln Ln m m �• T T m ai � c c c c c E E E m m c c w w w> m E m E m E m E m E m o m 0 m 0 0 00 >,Q m N X s s s U U d' l0 00 OC2 lii Q E E w 'a _O m p 0 ai ai ai ai ai » » > = m Q E E E n n n n m m m m m (v o 0 0 l ad 0 0 0 0 g 0 01010 (7 l7 U- a. Q Q U U U o EMI O O LM LM rl M li 00 rl 0 0 0 0 O W ce LM H H WLU J Q N 0 0 0 o d rq N L0 d' O O O •O N O C C m N d U m c D w LLI 'O Z O t5 W V) W W O r_ Z V 0 z co Z W W cc a 2 W N N r u O E c� u a) w C O a O C �o 7 O O O O N (> M M a E O Q E O _ m oo Ml 7 I O O O O O O n O n u_ +' t O t a_ U � � 3 0 Q, u- oo 00 Ln O cJ 0 0 0 ui o ui 14 O 14 pn p V 00 'i N ei O M W— w r N C � 7 O U U U U W W W W W W U U U U U W In In In Q (a (a (a (a J J J J J J (a W (a W (a W W W J J J J W W W W O H O O O O O O O O O O O O O O O O O O m U O O O O O O O O O O O O O O O O O O N O O O O O t!1 t!1 O t!1 O O O O O O O O O o o o o w m O N ,l M O o o o o w O O W O O O O H c-I c-I H O Ln Ln Ln O H Ln O ' .--I o0 O t0 o0 "I c-I .l W lr` N 0.lmLrnr`rn -i"tLnl0n O 1- N 1' 1 d' Vl l0 r o0 T e l �--� IV �--� N N N N N Z z N N N N N N N N N In N N N N N N N N to N N N N N N n V1 to In N In N In N IN N IN N to to Q N E E c c c m wE E o c o o p p Q ° m m en m en u s u E O m E a, E E (a a) a, a, a, a, Y v o L u °A O o c c p t p E c E Q �t t0 .� L a, a, a, a, a, o o U C � ? O O O O- cL N L L L L L C Qo Qai aivvoo'� u u u u u— a a ` C C C C C N uu u EL EL 00 O N t0 Q' d W Y Y Y �f' cn i6 r` cT) ° � C C C a) a) a a a Q o Q� O p 3 3aaaa ai ai ai ai airn O ��i1 mil ��il Q 3 3 (.J C7 Vr Vr N N In I In I In In C C C C C E O N J mi O O O O 14 M M O O W M 01 �O Iq 00 u a V O O O -6 -6 C a, O C o a 0 N D a) u a c D C Cf c� 'O C O O m N W to a OC r R L Nf z _O F- J V J V z co r ri O N N oq cq O 01 N rl 00 LO M 0 u i Ln 0) M N M Ln ri to z ° m c v ac m 0 o z aQi � u m E N Z m E o Z Q m O _ N O 3 ai bv « o > N _ ac ae O u N N m N 0 a 00^ m 0 W -, m 9 0 0 M o O LD � _ Ln O O Ln LnO 0 o O1 M OR 01 O O 6_Ln a Is v r Q M Ln N M ri �_ a ai � ai M V V E z c f0 L v 'O a a o a ° a Q aa) m �w a U w u O c m � Q N 0 z '_' m £ z c. 4 Vf Vf Vf Vf Vf Vf Vf Vf O o! a H v o z o oR 0 v o x cc + y + a: e o N h + x a x 00 00 N 00 om v Q J a v axo v @ o 3 m a) a) m N E o IZ33 d N Occ N 00 O. > O = 'O N Op0 Ol ^ O. 0 a CL M CaJ .0 0.S F m W V lfl M N C O N _ U >. cn O M a) GOV l0 p C O O O p -� rl m D. lfl r♦ O N L N E ..O O `^ N V"" Q C E > O` N 2 W CC O c O Ui E m o .O aE m c a m c X Oall O w O 2 @ W N c c NC Ol c E C C c O o G c g Ni o 0 aco, i o C a v all L° m n a` m c 3 a E v o v o cc a m 3 v c v c c c w 7 ai z¢ a Q _ a m v c c a o U y a~ E E E o 'm v v - c fcc6 C m z w d lL 11 s d E W N 'x W W o N o w 0 w m C m C N > U G o m p U 0 m m E w w Y t w v 'o a 0 m h w on w w o 3 w w 0o Y o c o z " m w o E n = o c - Z w O > E w n 10 `o n o w ° o w u _ � w ti Y o m o a t c a N c W V a v _ E a E o `o w o 3 0 o y m a t O J o E w o w $ v E w - oc a a m EEm w Y > > Y j v o w o `w y c o E J v y j` w E w o w `o > o o w a w w Y o m C O y j 0� 2 > m m 3 ` ` E > w m2p u ® w o 3 $ ° 0cf ? 0 o _ w a Y Y E > ' O .60 L O Z Z _ m # t Nm 00 N N d K KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL STORMWATER FACILITY SUMMARY SHEET DDES Permit Number (provide one Stormwater Facility Summary Sheet per Natural Discharge Location) Overview: Project Name Grant Avenue Townhomes Date Downstream Drainage Basins Major Basin Name Black River Immediate Basin Name Flow Control: Thunder Hills Creek Flow Control FacilityName/Number Combined detention/wet vault /1 Facility Location Near the west property line of the site If none, Flow control provided in regional/shared facility (give location) No flow control required Exemption number General Facility Information: Type/Number of detention facilities: Type/Number of infiltration facilities: ponds ponds 1 vaults tanks tanks trenches Control Structure Location At the northwest corner of the combined detention/wet vault 1-8" RISER W/1 ORIFICE AND SOLID TOP Type of Control Structure 1— 1 2 n RTC W/2 ORTFTC'FS Number of Orifices/Restrictions Size of Orifice/Restriction: No. 2 No. 3 No. 4 No. I 1.25" M Flow Control Performance Standard Level 2 (forest existing condition) 2009 Surface Water Design Manual 1 /9/2009 1 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL Live Storage Volume 1.0 Number of Acres Served 28,800 cf. . Depth 2.11 Number of Lots 1 Dam Safety Regulations (Washington State Department of Ecology) Reservoir Volume above natural grade N/A Depth of Reservoir above natural grade N/A Facility Summary Sheet Sketch Volume Factor of Safety All detention, infiltration and water quality facilities must include a detailed sketch. 01"x17" reduced size plan sheets may be used) 2009 Surface Water Design Manual 1/9/2009 2 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL Water Quality: Type/Number of water quality facilitiesBMPs: biofiltration swale (regular/wet/ or continuous inflow) large) large) above combined detention/wetpond sand filter (basic or large) sand filter, linear (basic or sand filter vault (basic or (wetpond portion basic or large) sand bed depth (inches) 1 combined detention/wetvault stormwater wetland filter strip 1 storm filter flow dispersion wetpond (basic or large) farm management plan landscape management plan oil/water separator (baffle or coalescing plate) Liner? catch basin inserts: Manufacturer pre -settling pond pre -settling structure: Manufacturer wetvault Is facility Lined? If so, what marker is used high flow bypass structure (e.g., flow-splitter catch basin) source controls Design Information Water Quality design flow 0.042 cfs (StormFilter manhole w/3 CSF cartridges) Water Quality treated volume (sandfilter) Water Quality storage volume (wetpool) 13 , 600 cf . Facility Summary Sheet Sketch 2009 Surface Water Design Manual 1/9/2009 3 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL All detention, infiltration and water quality facilities must include a detailed sketch. (11"x17" reduced size plan sheets may be used) 2009 Surface Water Design Manual 1/9/2009 4 RECORDING REQUESTED BY AND WHEN RECORDED MAIL TO: CITY CLERK'S OFFICE CITY OF RENTON 1055 SOUTH GRADY WAY RENTON WA 98057 DECLARATION OF COVENANT FOR MAINTENANCE AND INSPECTION OF FLOW CONTROL BMPS Grantor: vt pvAn � '51 r l't Grantee: City of Renton Legal Description: Additional Legal(s) on: A V` ikC he A S ' Assessor's Tax Parcel ID#: 2-0 Z-305 IN CONSIDERATION of the approved City of Renton(check one of the following) ❑ residential building permit, ZI commercial building permit,14 clearing and grading permit, ❑ subdivision permit, or ❑ short subdivision permit for Application File N LU SWP 1•5-000 8g relating to the real property ("Property") described above, the Grantor(s), the owner(s) in fee of that Property, hereby covenants(covenant) with City or Renton, a political subdivision of the state of Washington, that he/she(they) will observe, consent to, and abide by the conditions and obligations set forth and described in Paragraphs 1 through 8 below with regard to the Property. Grantor(s) hereby grants(grant), covenants(covenant), and agrees(agree) as follows: 1. Grantor(s) or his/her(their) successors in interest and assigns ("Owners") shall retain, uphold, and protect the stormwater management devices, features, pathways, limits, and restrictions, known as flow control best management practices ("BMPs"), 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 BMPs as described in the approved Design and Maintenance Details for each BMP attached hereto and incorporated herein as Exhibit B. 3. City or Renton shall provide at least 30 days written notice to the Owners that entry on the Property is planned for the inspection of the BMPs. After the 30 days, the Owners shall allow the City of Renton to enter for the sole purpose of inspecting the BMPs. In lieu of inspection by the City, the Owners may elect to engage a licensed civil engineer registered in the state of Washington who has expertise in drainage to inspect the BMPs and provide a written report describing their condition. If the engineer option is chosen, the Owners shall provide written notice to the City of Renton within fifteen days of receiving the City's notice of inspection. Within 30 days of giving this notice, the Owners, or the engineer on behalf of the Owners, shall provide the engineer's report to the City of Renton. If the report is not provided in a timely manner as specified above, the City of Renton may inspect the BMPs without further notice. 4. If the City determines from its inspection, or from an engineer's report provided in accordance with Paragraph 3, that maintenance, repair, restoration, and/or mitigation work is required for the BMPs, The City shall notify the Owners of the specific maintenance, repair, restoration, and/or mitigation work (Work) required under RMC 4-6-030. The City shall also set a reasonable deadline for completing the Work or providing an engineer's report that verifies completion of the Work. After the deadline has 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 City 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 6. Any notice or approval required to be given by one party to the other under the provisions of this Declaration of Covenant shall be effective upon personal delivery to the other party, or after three (3) days from the date that the notice or approval is mailed with delivery confirmation to the current address on record with each Party. The parties shall notify each other of any change to their addresses. 7. This Declaration of Covenant is intended to promote the efficient and effective management of surface water drainage on the Property, and it shall inure to the benefit of all the citizens of the City of Renton and its successors and assigns. This Declaration of Covenant shall run with the land and be binding upon Grantor(s), and Grantor's(s') successors in interest and assigns. 8. This Declaration of Covenant may be terminated by execution of a written agreement by the Owners and the City of Renton that is recorded by King County in its real property records. IN WITNESS WHEREOF, this Declaration of Covenant for the Maintenance and Inspection of Flow Control BMPs is executed this day of , 20 GRANTOR, owner of the Property GRANTOR, owner of the Property STATE OF WASHINGTON ) COUNTY OF KING )ss. On this day personally appeared before me: , to me known to be the individual(s) described in and who executed the within and foregoing instrument and acknowledged that they signed the same as their flee 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 Washington, residing at My appointment expires w U N N C9 F�- Z w 2 w ti 0 02 Y W-rl w v N o o II Ul. II II II II II II II II II II II II II II II II II II II II L QI N m =Q X W V C.2.10 NATIVE GROWTH RETENTION CREDIT c) Any portion of the area credited as mitigated that is pollution -generating impervious surface must be less than 5,000 square feet on any one site unless the surface is served by a water quality treatment facility designed by a civil engineer in accordance with Section 1.2.8 of the SWDM. C.2.10.2 EXAMPLE SIZING CALCULATION Area of target impervious surface to be credited as mitigated: 500 square feet Donor area of native vegetated surface that must be preserved: 500 x 3.5 = 1,750 square feet C.2.10.3 MAINTENANCE INSTRUCTIONS If the native growth retention credit flow 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.1.3.3 (p. C-18). The intent of these instructions is to explain to future property owners, the purpose of the BMP and how it must be maintained and operated. These 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 will be posted on King County's Sinface Water Design Manual website. TEXT OF INSTRUCTIONS Your property contains a stormwater management flow control BMP (best management practice) known as "native growth retention," the practice of preserving a portion of a property in a native vegetated condition (e.g., forest) so as to minimize increases in stormwater runoff from clearing and to offset the stormwater runoff impacts caused by impervious surfaces on your property. This native vegetated area on your property was set aside by covenant as "native growth retention area." The "native growth retention area" is delineated on the flow control BMP site plan attached to the covenant. The trees, vegetation, ground cover, and soil conditions in this area may not be disturbed, except as allowed by the following provisions: 1. Trees may be harvested in accordance with a King County -approved forest management plan. 2. Individual trees that have a structural defect due to disease or other defects, and which threaten to damage a structure, road, parking area, utility, or place of employment or public assembly, or block emergency access, may be topped, pruned, or removed as needed to eliminate the threat. 3. Dead or fallen trees, tree limbs within ten feet of the ground, and branches overhanging a residence may be removed to reduce the danger of wildfire. 4. Noxious weeds (i.e., plant species listed on the State noxious weed list in Chapter 16-750 WAC) and invasive vegetation (i.e., plant species listed as obnoxious weeds on the noxious weed list adopted by the King County Department of Natural Resources and Parks) may be removed. 5. Passive recreation uses and related facilities, including pedestrian, equestrian community and bicycle trails, nature viewing areas, fishing and camping areas, and other similar uses that do not require permanent structures, are allowed if clearing and soil compaction associated with these uses and facilities does not exceed eight percent of the native growth retention area. 2009 Surface Water Design Manual — Appendix C 1/9/2009 C-79 SECTION C.2 FLOW CONTROL BMPs Design Specifications A minimum of 6 inches of free draining base material (sand or gravel) is required under the modular grid material. 2. The modular grid material must be installed according to the manufacturer's instructions. 3. The surface area of the modular grid openings must be at least 50% of the total surface area of the modular grid pavement. 4. The modular grid openings must be filled with gravel, sand, or a mixture of both. 5. Smooth surface walkways may be run across modular grid pavements, provided the impervious surfaced walkways do not exceed 10 percent of the total pavement surface. C.2.6.6 GRASSED MODULAR GRID PAVEMENT Grassed modular grid pavement is basically a modular grid pavement with grass planted in the openings or in a thin layer of soil over the grid material. The benefits of this measure are reduced runoff peaks and volumes resulting from the increased infiltration of stormwater, the increased water storage provided in the grid soil and base, and the increased evapotranspiration provided by the grass. The grassed surface also helps remove pollutants that are left behind by vehicles. Uses: Low -traffic or infrequently used areas such as low -traffic driveways, overflow parking, event parking, church parking, employee parking, maintenance access roads, etc.; they are not allowed in King County road right-of-way. Design Specifications 1. A minimum of 6 inches of free draining base material (sand or gravel) is required under the modular grid material. 2. The modular grid material must be installed according to the manufacturer's instructions. 3. The surface area of the modular grid openings must be at least 50% of the total surface area of the modular grid pavement. 4. The modular grid openings must be filled with a sandy soil mix suitable for growing grass as specified by the manufacturer's instructions or a landscape architect. 5. Smooth surface walkways may be run across modular grid pavements, provided the impervious surfaced walkways do not exceed 10 percent of the total pavement area. C.2.6.7 MAINTENANCE INSTRUCTIONS FOR PERMEABLE PAVEMENT If the permeable pavement flow control BMP is proposed for a project, the following maintenance and operation instructions, plus any provided by the manufacturer or installer, must be recorded as an attachment to the required declaration of covenant and grant of easement per Requirement 3 of Section C.1.3.3 (p. C-18). The intent of these instructions is to explain to future property owners, the purpose of the BMP and how it must be maintained and operated. These instructions are intended to be a minimum; DDES may require additional instructions based on site -specific conditions or manufacturer's recommendations. Also, as the County gains more experience with the maintenance and operation of these BMPs, future updates to these instructions will be posted on King County's Sznface Water Design Manual website. i TEXT OF INSTRUCTIONS FOR NON -VEGETATED PERMEABLE PAVEMENT Your property contains a stormwater management flow control BMP (best management practice) called "permeable pavement," which was installed to minimize the stormwater quantity and quality impacts of 1/9/2009 L_ 119 i ' ,'7.� f ' 2009 Surface Water Design Manual — Appendix C C-66 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: ❑ 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 details 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. Prolonged 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, and/or broken paving units. P 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 grid 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 surface. 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 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. The grassed surface of the pavement must be regularly mowed and maintained in a good condition. Bare spots must be replanted in the spring or fall. �Xi� i i I l; A 2009 Surface Water Design Manual — Appendix C 1/9/2009 C-67 RECORDING REQUESTED BY AND WHEN RECORDED MAIL TO: CITY CLERK'S OFFICE CITY OR RENTON 1055 SOUTH GRADY WAY RENTON WA 98057 DECLARATION OF COVENANT FOR INSPECTION AND MAINTENANCE OF STORMWATER FACILITIES AND BMPS Grantor: G7/ 11✓�'V1�U ► �� 1 Grantee: City or Renton Legal Description: Additional Legal(s) on: Assessor's Tax Parcel ID#: Z-0 2-; p — ! 05 IN CONSIDERATION of the approved City or Renton (S(r ., yA & S-An no�,&_ permit for application file No LU SWP )5-0019&-55 relating to the real property ("Property") described above, the Grantor(s), the owner(s) in fee of that Property, hereby covenants(covenant) with the City or Renton, a political subdivision of the state of Washington, that he/she(they) will observe, consent to, and abide by the conditions and obligations set forth and described in Paragraphs 1 through 10 below with regard to the Property, and hereby grants(grant) an easement as described in Paragraphs 2 and 3. Grantor(s) hereby grants(grant), covenants(covenant), and agrees(agree) as follows: 1. The Grantor(s) or his/her(their) successors in interest and assigns ("Owners") shall at their own cost, operate, maintain, and keep in good repair, the Property's stormwater facilities and best management practices ("BMPs") identified in the plans and specifications submitted to City of Renton for the review and approval of permit(s) #: L.A I,5 -MAK5' . Stormwater facilities include pipes, swales, tanks, vaults, ponds, and other engineered structures designed to manage stormwater on the Property. Stormwater BMPs include dispersion and infiltration devices, native vegetated areas, permeable pavements, vegetated roofs, rainwater harvesting systems, reduced impervious surface coverage, and other measures designed to reduce the amount of stormwater runoff on the Property. 2. 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 specified in this Declaration of Covenant and in accordance with RMS 4-6-030. This right of ingress and egress, right to inspect, and right to perform required maintenance or repair as provided for in Section 3 below, shall not extend over those portions of the Property shown in Exhibit "A." 3. If City of Renton determines that maintenance or repair work is required to be done to any of the stormwater facilities or BMPs, City of Renton shall give notice of the specific maintenance and/or repair work required pursuant to RMC 4-6-030. The City shall also set a reasonable time in which such work is to be completed by the Owners. If the above required maintenance or repair is not completed within the time set by the City, the City may perform the required maintenance or repair, and hereby is given access to the Property, subject to the exclusion in Paragraph 2 above, for such purposes. Written notice will be sent to the Owners 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 (7) day notice period will be waived and 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. 5. 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 City to address hazardous conditions as described in Paragraph 4. Such responsibility shall include reimbursement to the City within thirty (30) days of the receipt of the invoice for any such work performed. 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 fiom City of Renton prior to filling, piping, cutting, or removing vegetation (except in routine landscape maintenance) in open vegetated stormwater facilities (such as swales, channels, ditches, ponds, etc.), or performing any alterations or modifications to the stormwater facilities and BMPs referenced in this Declaration of Covenant. 7. Any notice or consent required to be given or otherwise provided for by the provisions of this Agreement shall be effective upon personal delivery, or three (3) days after mailing by Certified Mail, return receipt requested. 8. With regard to the matters addressed herein, this agreement constitutes the entire agreement between the parties, and supersedes all prior discussions, negotiations, and all agreements whatsoever whether oral or written. 9. This Declaration of Covenant is intended to protect the value and desirability of the real property described above, and shall inure to the benefit of all the citizens of the City of Renton and its successors and assigns. This Declaration of Covenant shall run with the land and be binding upon Grantor(s), and Grantor's(s') successors in interest, and assigns. 10. This Declaration of Covenant may be terminated by execution of a written agreement by the Owners and the City that is recorded by King County in its real property records.IN WITNESS WHEREOF, this Declaration of Covenant for the Inspection and Maintenance of Stormwater Facilities and BMPs is executed this day of , 20 GRANTOR, owner of the Property GRANTOR, owner of the Property STATE OF WASHINGTON ) COUNTY OF KING )ss. On this day personally appeared before me: , to me known to be the individual(s) 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 Washington, residing at My appointment expires QI N m =Q X WV X. Operations and Maintenance Manual The onsite storm facilities will be maintained by the property owner and manager 53 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES This appendix contains the maintenance requirements for the following typical stormwater control facilities and components: No. 1 — Detention Ponds (p. A-2) No. 2 — Infiltration Facilities (p. A-3) No. 3 — Detention Tanks and Vaults (p. A-5) No. 4 — Control Structure/Flow Restrictor (p. A-7) No. 5 — Catch Basins and Manholes (p. A-9) No. 6 — Conveyance Pipes and Ditches (p. A-11) No. 7 — Debris Barriers (e.g., Trash Racks) (p. A-12) No. 8 — Energy Dissipaters (p. A- 13) No. 9 —Fencing (p. A-14) No. 10 — Gates/Bollards/Access Barriers (p. A-15) No. 11 —Grounds (Landscaping) (p. A-16) No. 12 — Access Roads (p. A-17) No. 13 — Basic Biofiltration Swale (grass) (p. A-18) No. 14 — Wet Biofiltration Swale (p. A-19) No. 15 — Filter Strip (p. A-20) No. 16 — Wetpond (p. A-21) No. 17 — Wetvault (p. A-23) No. 18 — Stormwater Wetland (p. A-24) No. 19 — Sand Filter Pond (p. A-26) No. 20 — Sand Filter Vault (p. A-28) No. 21— Stormfilter (Cartridge Type) (p. A-30) No. 22 — Baffle Oil/Water Separator (p. A-32) No. 23 — Coalescing Plate Oil/Water Separator (p. A-33) No. 24 — Catch Basin Insert (p. A-35) 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-1 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 3 - DETENTION TANKS AND VAULTS Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Site Trash and debris 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 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. Tank or Vault Trash and debris Any trash and debris accumulated in vault or tank No trash or debris in vault. Storage Area (includes floatables and non-floatables). Sediment Accumulated sediment depth exceeds 10% of the All sediment removed from storage accumulation diameter of the storage area for length of area. storage vault or any point depth exceeds 15% of diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than %2 length of tank. Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of Any part of tank/pipe is bent out of shape more Tank repaired or replaced to design. shape than 10% of its design shape. Gaps between A gap wider than'% -inch at the joint of any tank No water or soil entering tank sections, damaged sections or any evidence of soil particles entering through joints or walls. joints or cracks or the tank at a joint or through a wall. tears in wall Vault Structure Damage to wall, Cracks wider than %-inch, any evidence of soil Vault is sealed and structurally frame, bottom, and/or entering the structure through cracks or qualified sound. top slab inspection personnel determines that the vault is not structurally sound. Inlet/Outlet Pipes Sediment Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlet/outlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than'% -inch at the joint of the No cracks more than'/< -inch wide at inlet/outlet pipes or any evidence of soil entering the joint of the inlet/outlet pipe. at the joints of the inlet/outlet pipes. 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-5 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO.3 - DETENTION TANKS AND VAULTS Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Manhole access covered. Any open manhole requires immediate maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. not working maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Cover/lid difficult to One maintenance person cannot remove Cover/lid can be removed and remove cover/lid after applying 80 Ibs of lift. reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access Damaged or difficult Large access doors or plates cannot be Replace or repair access door so it doors/plate to open opened/removed using normal equipment. can opened as designed. Gaps, doesn't cover Large access doors not flat and/or access Doors close flat and covers access completely opening not completely covered. opening completely. Lifting Rings missing, Lifting rings not capable of lifting weight of door Lifting rings sufficient to lift or rusted or plate. remove door or plate. 1/9/2009 2009 Surface Water Design Manual — Appendix A A-6 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 cubic foot which No Trash or debris blocking or is located immediately in front of the structure potentially blocking entrance to opening or is blocking capacity of the structure by structure. more than 10%. Trash or debris in the structure that exceeds 1/3 No trash or debris in the structure. the depth from the bottom of basin to invert the lowest pipe into or out of the basin. Deposits of garbage exceeding 1 cubic foot in No condition 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 1/4 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 '/< inch. Frame not 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 walls or Cracks wider than'/. inch and longer than 3 feet, Structure is sealed and structurally bottom any evidence of soil particles entering structure sound. through cracks, or maintenance person judges that structure is unsound. Cracks wider than inch and longerthan 1 foot No cracks more than'/4 inch wide at at the joint of any inlet/outlet pipe or any evidence the joint of inlet/outlet pipe. of soil particles entering structure through cracks. Settlement/ Structure has settled more than 1 inch or has Basin replaced or repaired to design misalignment rotated more than 2 inches out of alignment. standards. Damaged pipe joints Cracks wider than'/. -inch at the joint of the No cracks more than wide at inlet/outlet pipes or any evidence of soil entering the joint of inlet/outlet pipes. the structure at the joint of the inlet/outlet 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 control BMPs implemented if appropriate. No contaminants present other than a surface oil film. 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. FROP-T Section Damage T section is not securely attached to structure T section securely attached to wall wall and outlet pipe structure should support at and outlet pipe. least 1,000 Ibs of up or down pressure. Structure is not in upright position (allow up to Structure in correct position. 10% from plumb). Connections to outlet pipe are not watertight or Connections to outlet pipe are water show signs of deteriorated grout. tight; structure repaired or replaced and works as designed. 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. Replace cleanout gate. 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-7 APPENDIX A MAINTENANCE REQUIREMENTS 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 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 maintenance 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 of all obstructions and blocking the plate. works as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having the Pipe is free of all obstructions and potential of blocking) the overflow pipe. works as designed. Deformed or damaged Lip of overflow pipe is bent or deformed. Overflow pipe does not allow lip overflow at an elevation lower than design Inlet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlet/outlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than''/2-inch at the joint of the No cracks more than 1/4-inch wide at inlet/outlet pipes or any evidence of soil entering the joint of the inlet/outlet pipe. at the joints of the inlet/outlet pipes. Metal Grates Unsafe grate opening Grate with opening wider than 7/8inch. 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. 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 Cover/lid not in place Cover/lid is missing or only partially in place. Cover/lid protects opening to Any open structure requires urgent structure. maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. Not Working maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Cover/lid difficult to One maintenance person cannot remove Cover/lid can be removed and Remove cover/lid after applying 80 lbs. 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 of 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 % 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. '/s 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 animals 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 3% 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 % inch. Frame not 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 walls or bottom Cracks wider than '% inch and longer than 3 feet, any evidence of soil particles entering catch Catch basin is sealed and structurally sound. basin through cracks, or maintenance person judges that catch basin is unsound. Cracks wider than Yz inch and longer than 1 foot No cracks more than inch wide at at the joint of any inlettoutlet pipe or any evidence the joint of inlet/outlet pipe. of soil particles entering catch basin through cracks. Settlement/ Catch basin has settled more than 1 inch or has Basin replaced or repaired to design misalignment rotated more than 2 inches out of alignment. standards. Damaged pipe joints Cracks wider than '%-inch at the joint of the No cracks more than 1/4-inch wide at inlettoutlet pipes or any evidence of soil entering the joint of inlettoutlet pipes. the catch basin at the joint of the inlet/outlet 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 control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. Inlettoutlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlettoutlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than YZ-inch at the joint of the No cracks more than wide at inlettoutlet pipes or any evidence of soil entering the joint of the inlettoutlet pipe. at the joints of the inlettoutlet pipes. 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-9 APPENDIX A MAINTENANCE REQUIREMENTS 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 Metal Grates Unsafe grate opening Grate with opening wider than 7/8 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 Grate missing or broken member(s) of the grate. Grate is in place and meets design Any open structure requires urgent standards. maintenance. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Cover/lid protects opening to Any open structure requires urgent structure. maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. Not Working maintenance person with proper tools. Bolts cannot be seated. Self-locking coverllid does not work. Cover/lid difficult to One maintenance person cannot remove Cover/lid can be removed and Remove cover/lid after applying 80 lbs. of lift. reinstalled by one maintenance person. 1/9/2009 2009 Surface Water Design Manual — Appendix A A-10 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 & debris Accumulated sediment or debris that exceeds Water flows freely through pipes. accumulation 20% of the diameter of the pipe. Vegetation/roots Vegetation/roots 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 control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Damage to protective Protective coating is damaged; rust or corrosion Pipe repaired or replaced. coating or corrosion is weakening the structural integrity of any part of pipe. Damaged Any dent that decreases the cross section 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 debris cleared from square feet of ditch and slopes. ditches. Sediment Accumulated sediment that exceeds 20% of the Ditch cleaned/flushed of all sediment accumulation design depth. and debris 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 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. Vegetation Vegetation 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. 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-11 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 and Cross Members Missing or damaged parts Missing or broken boards, post out of plumb by more than 6 inches or cross members broken No gaps on fence due to missing or broken boards, post plumb to within 1'Y2 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. Damaged 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'Y2 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. grid size. 1 /9/2009 2009 Surface Water Design Manual — Appendix A A-14 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 10 - GATES/BOLLARDS/ACCESS BARRIERS Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Chain Link Fencing Damaged or missing Missing gate. Gates in place. Gate members Broken or missing hinges such that gate cannot Hinges intact and tubed. 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 diameter ball could fit through. Fabric mesh openings within 50% of 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 device 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 motorized 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 lock 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. 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-15 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 11 -GROUNDS (LANDSCAPING) Maintenance Defect or Problem Conditions When Maintenance is Needed Results 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 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. Trees and Shrubs Hazard Any tree or limb of a tree identified as having a No hazard trees in facility. potential to fall and cause property damage or threaten human life. A hazard tree identified by a qualified arborist must be removed as soon 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 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. 1/9/2009 2009 Surface Water Design Manual — Appendix A A-16 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, 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. one 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 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. Blocked roadway Any obstruction which reduces clearance above Roadway overhead clear to 14 feet road surface to less than 14 feet. high. 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 Ditches inches wide and 6 inches deep. matching the surrounding road. Weeds and brush Weeds and brush exceed 18 inches in height or Weeds and brush cut to 2 inches in hinder maintenance access. height or cleared in such a way as to allow maintenance access. Modular Grid Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of Pavement 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. Damaged or missing Access surface compacted because of broken on Access road surface restored so missing modular block. road infiltrates. 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-17 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 17 - WETVAULT Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Site Trash and debris Trash and debris accumulated on facility site. Trash and debris removed from facility site. Treatment Area Trash and debris Any trash and debris accumulated in vault No trash or debris in vault. (includes floatables and non-floatables). Sediment Sediment accumulation in vault bottom exceeds No sediment in vault. accumulation the depth of the sediment zone plus 6 inches. 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. Vault Structure Damage to wall, Cracks wider than 1/2-inch, any evidence of soil Vault is sealed and structurally frame, bottom, and/or entering the structure through cracks, vault does sound. top slab not retain water or qualified inspection personnel determines that the vault is not structurally sound. Baffles damaged Baffles corroding, cracking, warping and/or Repair or replace baffles or walls to showing signs of failure or baffle cannot be specifications. removed. Ventilation Ventilation area blocked or plugged. No reduction of ventilation area exists. Inlet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. Inlet/ouflet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlet/outlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than 1/2-inch at the joint of the No cracks more than %-inch wide at inlet/outlet pipes or any evidence of soil entering the joint of the inlet/outlet pipe. at the joints of the inlet/outlet pipes. Gravity Drain Inoperable valve Valve will not open and close. Valve opens and closes normally. Valve won't seal Valve does not seal completely. Valve completely seals closed. Access Manhole Access cover/lid Access cover/lid cannot be easily opened by one Access cover/lid can be opened by damaged or difficult to person. Corrosion/deformation of cover/lid. one person. open Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. not working maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Cover/lid difficult to One maintenance person cannot remove Cover/lid can be removed and remove cover/Ild after applying 80 Ibs of lift. reinstalled by one maintenance person. Access doors/plate Large access doors not flat and/or access Doors close flat and covers access has gaps, doesn't opening not completely covered. opening completely. cover completely Lifting Rings missing, Lifting rings not capable of lifting weight of door Lifting rings sufficient to lift or rusted or plate. remove door or plate. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-23 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO.21 - STORMFILTER (CARTRIDGE TYPE) Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Site Trash and debris Any trash or debris which impairs the function of Trash and debris removed from the facility. facility. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oils, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Life cycle System has not been inspected for three years. Facility is re -inspected and any needed maintenance performed. Vault Treatment Sediment on vault Greater than 2 inches of sediment. Vault is free of sediment. Area floor Sediment on top of Greater than % inch of sediment. Vault is free of sediment. cartridges Multiple scum lines Thick or multiple scum lines above top of Cause of plugging corrected, above top of cartridges. Probably due to plugged canisters or canisters replaced if necessary. cartridges underdrain manifold. Vault Structure Damage to wall, Cracks wider than '%-inch and any evidence of Vault replaced or repaired to design Frame, Bottom, and/or soil particles entering the structure through the specifications. Top Slab cracks, or qualified inspection personnel determines the vault is not structurally sound. Baffles damaged Baffles corroding, cracking warping, and/or Repair or replace baffles to showing signs of failure as determined by specification. maintenance/inspection person. Filter Media Standing water in 9 inches or greater of static water in the vault for No standing water in vault 24 hours vault more than 24 hours following a rain event and/or after a rain event. overflow occurs frequently. Probably due to plugged filter media, underdrain or outlet pipe. Short circuiting Flows do not properly enter filter cartridges. Flows go through filter media. Underdrains and Sediment/debris Underdrains or clean -outs partially plugged or Underdrains and clean -outs free of Clean -Outs filled with sediment and/or debris. sediment and debris. Inlet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlet/outlet 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 wide at inlet/outlet pipes or any evidence of soil entering the joint of the inlet/outlet pipe. at the joints of the inlet/outlet pipes. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Manhole access covered. Any open manhole requires immediate maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. not working maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Cover/lid difficult to One maintenance person cannot remove Cover/lid can be removed and remove cover/lid after applying 80 Ibs of lift. reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access Damaged or difficult Large access doors or plates cannot be Replace or repair access door so it doors/plate to open opened/removed using normal equipment. can opened as designed. 1 /9/2009 2009 Surface Water Design Manual — Appendix A A-30 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO.21 - STORMFILTER (CARTRIDGE TYPE) Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Gaps, doesn't cover Large access doors not flat and/or access Doors close flat and cover access completely opening not completely covered. opening completely. Lifting Rings missing, Lifting rings not capable of lifting weight of door Lifting rings sufficient to lift or rusted or plate. remove door or plate. 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-31