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Home My WebLink AboutMiscEast Elevation 221st PLACE SE 1/8" = 1'0" el CD () ;;c, )> West Elevation oR1vE-THRu 1 /8" = 1'0" rm 0::, () ;;o )> South Elevation PARKING LOT 1/8" = 1'0" rm CD () ;;o > North Elevation sE s6th sT 1/8" = 1'0" [!!1 0::, () ~ )> I I I ( TECHNICAL INFORMATION REPORT January 14, 2014 PROJECT: Taco Time -Renton Highlands 4114 N.E. 4TH Street Renton, WA 98059 APPLICANT: Bellevue TI, LLC. 3300 Maple Valley Highway Renton, WA 98058 PROPERTY OWNER: Bellevue TI, LLC. 3300 Maple Valley Highway Renton, WA 98058 ENGINEER: BCRA Civil Engineering 2106 Pacific Avenue, Suite 300 Tacoma, WA 98402 PREPARED BY: Andrew Cirillo, E.I.T acirillo@bcraengineering.com REVIEWED BY; Justin Goroch, P.E. jgoroch@bcraengineering.com I hereby state that this report for the Taco Time Renton Highlands project has been prepared by me or under my supervision and meets the standard of care and expertise which is usual and customary in this community for professional engineers. PRELIMINARY 1 Table of Contents Section 1 -Project Overview ..................................................................................... 4 Predeveloped Conditions .............................................................................................. 4 Developed Conditions ................................................................................................... 4 Section 2 -Conditions and Requirements Summary ................................................ 17 Section 3 -Offsite Analysis ...................................................................................... 19 Task 1-Study Area Definition and Maps ................................................................... 20 Task 2 -Resource Review ........................................................................................... 22 Task 3 -Field Inspection ............................................................................................. 27 Task 4 -Drainage System Description and Problem Descriptions ............................. 27 Task 5 -Mitigation of Existing or Potential Problems ................................................ 27 Section 4 -Flow Control and Water Quality Facility Analysis and Design .................. 28 Existing Site Hydrology (Part A) .................................................................................. 28 Developed Site Hydrology (Part B) ............................................................................. 28 Performance Standard (Part() ................................................................................... 28 Flow Control System (Part D) ...................................................................................... 29 Water Quality System (Part E) .................................................................................... 35 Section 5 -Conveyance System Analysis and Design ................................................ 41 Section 6 -Special Reports and Studies ................................................................... 46 Section 7 -Other Permits ........................................................................................ 68 Section 8 -CSWPPP Analysis and Design ................................................................. 69 Section 9 -Bond Quantities, Facility Summaries, and Declaration of Covenant ........ 70 Section 10-Operations and Maintenance Manual .................................................... 71 BCRADESIGN.COM 2 Table of Figures Figure 1-1 TIR Worksheet ...................................................................................................................... 6 Figure 1-2: Site Location ...................................................................................................................... 11 Figure 1-3: Drainage Basins ................................................................................................................ 12 Figure 1-4: Water Quality Subbasins .................................................................................................. 13 Figure 1-5 Soil Map ............................................................................................................................. 14 Figure 3-1: Tributary Map ................................................................................................................... 21 Figure 3-2: Sensitive Areas Map ......................................................................................................... 23 Figure 3-3: Flood Map ......................................................................................................................... 26 Figure 4-1: Duration Analysis Plot ....................................................................................................... 35 Figure 4-2: Underground Detention System Details ........................................................................... 37 Figure 4-3: Storm filter Details ............................................................................................................. 39 Figure 5-1: Conveyance Sizing Areas .................................................................................................. 41 Figure 5-2: Offsite Pipe Relocation Tai/water ..................................................................................... 44 BCRADESIGN.COM 3 l!1 CCI n ;,o > Section 1 -Project Overview The proposed project is the redevelopment of a single parcel, 1023059132, zoned CA-1 to a commercial use. Currently the project site consists of a single commercial unit and its associated parking, encompassing the entirety of the 0.77 acre parcel. The proposed redevelopment of this project will consist of the relocation and reconstruction of the existing commercial building, a Taco Time restaurant, and the construction of a second commercial building. This redevelopment will also include the associated parking and associated utility improvements, such as water service connections, sanitary sewer connections, gas connections, and power and communication services. Associated stormwater drainage improvements will include the relocation of a public storm main traversing the site as well as the installation of an underground detention system to control the flow of onsite stormwater. The site is located at 4114 N.E. 4th Street in Renton, Washington near the intersection of N.E. 4th Street and Union Avenue as shown in Figure 1-2 at the end of this section. Predeveloped Conditions The predeveloped site consists of a single commercial building, a Taco Time restaurant, approximately 2,700 square feet in size. The remainder of the site consists largely of the parking area associated with the commercial building with a number of small landscaped areas. The general topography of the site consists of 2 feet of gain across the site from north to south (slopes at roughly 1-2%) and 5 feet of gain across the site from east to west (slopes roughly 2%), a total elevation difference gain of 7 feet from the southeast corner of the site to the northwest corner of the site. A generally flat site, there are no steep slopes on or near the project site. The existing site drains to catch basins located throughout the site. The runoff from the site is split in two directions leaving the site from the southwest and southeast corners. The stormwater leaving the site from the southwest corner is conveyed south across N.E. 4th Street in a storm main discharging at an outfall located in Maplewood Creek. The stormwater leaving the site from the southeast corner is conveyed east parallel with N.E. 4th Street for roughly 100 feet before entering a storm main and ultimately discharging at an outfall located in Maplewood Creek. Developed Conditions The proposed site is designed such that the developed conditions will mimic the predeveloped conditions. The proposed site will contain two commercial structures with the remainder of the site consisting largely of the parking area associated with the two buildings and associated BCRADESIGN.COM 4 landscaped areas. Interfacing with existing improvements on all four sides the developed site topography also mimics the predevloped site topography. The proposed site will drain runoff to various catch basins throughout the site. These catch basins will be draining to several underground detention tanks that will be used to regulate flow being discharged from the site. The stormwater entering the detention tanks will also undergo water quality treatment from one of two filters located within the conveyance system (see the North Filter and the South Filter on page 13) The developed site will also include the relocation of a public storm line traversing the site carrying offsite stormwater. The replaced line will be moved west, parallel to the lot boundary, and will be upsized from a 24" corrugated metal pipe (CMP) to a 36" lined corrugated polyethylene pipe (LCPE). Though the site is not tributary to this pipe a backwater analysis was performed to ensure capacity for the upsized section of pipe, the calculations and results of the backwater analysis can be found in Section 5 of this report. The developed site will also include the relocation of two private storm lines which traverse the site. The pipes will be rerouted in-kind, using the same size and material pipe that is in place. In total 145' of one pipe and 193' of another will be rerouted and replace with 218' and 195' of matching pipe respectively. The western pipe being rerouted is currently located within the project and received runoff generated within the project in the existing condition. In the developed condition the pipe's associated catch basin will be located outside the project site and will receive no runoff generated onsite. As no runoff is being added from the project site to either section of relocated pipe neither were reanalyzed for capacity. BCRADESIGN.COM 5 KING COlJNTY. WASIIINGTON. SlJRFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Project Owner ~B=•~lle~v~ue~n=, L=L~C ____ _ Phone (425)-988-2439 Address 3300 Maple Valley Highway Renton, WA 98058 Project Engineer _Ju_s_tin_G_o_ro_c_h _____ _ Company _B_CR_A _________ _ Phone (253) 627-4367 Part 3 TYPE OF PERMIT APPLICATION D Landuse Services Subdivison / Short Subd. / UPD IXI Buil~'--~--ices M/F ([;ommerical)/ SFR IXI Clearing and Grading IXI Right-of-Way Use D Other Part5 PLAN AND REPORT INFORMATION Technical Information Report Type of Drainage Review ®' Targeted (circle): Large Site Date (include revision dates): Date of Final: Part 6 ADJUSTMENT APPROVALS I Part 2 PROJECT LOCATION AND DESCRIPTION Project Name Taco Time Renton Highlands DOES Permit# ---------- Location Township 23 North ------ RangeO _s_E_a_st ____ _ Section 10 ------- Site Address 4114 N.E. 4th Street Renton, WA 98059 Part 4 OTHER REVIEWS AND PERMITS D DFWHPA D Shoreline D COE404 Management D DOE Dam Safety D Structural RockeryNault/ __ D FEMA Floodplain D ESA Section 7 D COE Wetlands D Other Site Improvement Plan (Engr. Plans) Type (circle one): ~/ Modified I I Site Date (include revision dates): Date of Final: Type (circle one): Standard / Complex / Preapplication / Experimental / Blanket Description: (include conditions in TIR Section 2) Date of Annroval: 6 2009 Surface Water Design Manual I 1/9/2009 KING COUNTY. WASHINGTON. SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes@ Describe: Start Date: Completion Date: Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan : E:.:a.:..:st--'-P'--"la.:..:te.::_au"-------------- Special District Overlays: :::U:..:rb::::anc:..:D:..:e:::si,.,gnc.:D::::is:..::tr.:.::ictc:..:D::....... ________________ _ Drainage Basin: Lower Cedar River Basin Stormwater Requirements: Flow Control Duration Standard (Forested Condition) Part 9 ONSITE AND ADJACENT SENSITIVE AREAS D River/Stream --------- D Lake D Wetlands----------- D Closed Depression _______ _ D Floodplain __________ _ D Other ___________ _ Part 10 SOILS Soil Type Slopes AgC 6%-15% D High Groundwater Table (within 5 feet) D Other D Additional Sheets Attached 2009 Surface Water Design Manual 2 D Steep Slope --------- D Erosion Hazard -------- D Landslide Hazard ------- D Coal Mine Hazard -------D Seismic Hazard _______ _ D Habitat Protection -------D __________ _ Erosion Potential Low D Sole Source Aquifer D Seeps/Springs 1/912009 7 KING COUNTY. WASHINGTON. SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE LIMITATION/ SITE CONSTRAINT D Core2 Offsite Anal:r:sis 0 Sensitive/Critical Areas D ~!;;PA D Qthtr D 0 Additional Sheets Attached Part 12 TIR SUMMARY SHEET lnrovide one TIR Summarv Sheet =r Threshold Discha~e Areal Threshold Discharge Area: Taco Time Renton Highlands I name or descrintionl Core Requirements (all 8 apply) Discharne at Natural Location Number al.Natural Discharae Locations: 1 Offsite Analysis Level: \.!J 2 / 3 dated: Flow Control Level: \.S;! 3 or Exemption Number /incl. facililv summarv sheet\ Small Site B s Conveyance System Spill containment located at: Erosion and Sediment Control ESC Sile Supervisor: Contact Phone: After Hours Phan-· Maintenance and Operation Responsibility: C Private)/ Public If Private. Maintenance Lna R..,,uired: Yes / No Financial Guarantees and Provided: Yes l{t!j Liabililv Water Quality Type: U3asic JI Sens. Lake / Enhanced Basicm / Bog (include facility summary sheet) or Exemption"'lllo. Landscane Manaaement Plan: Yes / No Sneclal Renu[rements las annllcab[el ~ Area Specific Drainage Type: CDA / SDO / MDP /BP/ LMP / Shared Fae. ( None) Renuirements Name: - Floodplain/Floodway Delineation Type: Major / Minor / Exemption e 100-year Base Flood Elevation (or range): Datum: Flood Protection Facilities Describe: Source Control Describe landuse: (comm./industrial landuse) Describe any structural controls: 8 2009 Surface Water Design Manual 3 1/9/2009 KI1'G COUNTY. WASHINGTON. SL'RFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Oil Control High-use Site: Yes I No Treatment BMP: Maintenance Agreement: Yes I No with whom? Other Drainage Structures Describe: Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION AFTER CONSTRUCTION D Clearing Limits I D Stabilize Exposed Surfaces D Cover Measures I-D Remove and Restore Temporary ESC Facilities :§: z 0 Perimeter Protection oO D Clean and Remove All Silt and Debris, Ensure D Traffic Area Stabilization UJ Cf) Operation of Permanent Facilities 0 Cf) D Flag Limits of SAO and open space D Sediment Retention :::::)-_.~ D Surface Water Collection 0CC preservation areas z:::::l D Other D Dewatering Control -Cf) UJ _. D Dust Control cc <i:: oz D Flow Control I-LL Part 14 STORMWATER FACILITY DESCRIPTIONS (Note: Include Facility Summary and Sketch) Flow Control T vne/Descri otion Water Qualitv T vne/Descriotion D Detention Underground Tank D Biofiltration D Infiltration 0 Wetpool D Regional Facility IKJ Media Filtration Stormfilter Cartridges D Shared Facility D Oil Control D Flow Control D Spill Control BMPs 0 Flow Control BMPs D Other D Other 9 2009 Surface Water Design Manual 4 1/9/2009 KING COUNTY. WASHINGTO~. SURFACE WATER DESIGN MAKUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 15 EASEMENTS/TRACTS Part 16 STRUCTURAL ANALYSIS Im Drainage Easement D Cast in Place Vault D Covenant D Retaining Wall D Native Growth Protection Covenant D Rockery > 4' High 0 Tract D Structural on Steep Slope D Other D 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 provided here is accurate. Sianed/Date 10 2009 Surface Water Design Manual l/912009 5 SAS Conslruction IE bth Pl • 0 C "' "' " • Dance Yer Socks Off Mobile DJ Service NE 7th St NE G1/i Pi Figure 1-2: Site Location N18th SI NE 8th St NE 7th Pl Nf 6th Pl f a NE 7th St "' ;:,. 0 ::, "P.: Remington & Scents " ~ NE o\nC' u = Forest'.'iew Apartments l!lJ tl1 () ;:o )> Ries Creativ • NE 6th St NE 6th St NE 6th St NE 5th Ct Keepsake '!I' Photo Classes s By Creme :t Creme Ith St &1g Skyline Sedan • .::i Services .,, ~ N't~ 5th St NE ,1th Pl J> < "' z m NE 5th Ct NE 5th St 24 Hour • Fitness Nf % Ct Ch1ldhme 1'I Safeway >, "' ;; 3 '.,: 0 ::, :,,. < "' z ca N[ 5th Ct Q ,; NE 5th Pl " ::, ~ z NE 5th S! m Highlands • Primary Care 0 C: < "' > < "' z rn Planet Bronze Tanning & Airbrush Studio • NE 4th St ~PROJECT SITE NE 4th St NE 4th St Pap Pin • " ~ Q. !< 0 Les Schwab Tire Center ~ ;;f. 3rd Ln NE 3rd Ct ·•: Heritage Park C ::, 0 ::, ~-< • Grass. Charles NE 2nd Pl "' NE 2nd SI z er United States Post Office 1 ~ j' 3 "' " cl- ~ Carl's Jr !' N~ 2nd r.t (D .,; NF 2nd Ln ::, ~~ 'o ':) ~ NE 3rd Ct Storage One On 4th c; r. C < ~- :,,. ~ z er NE l C, ::, Q z m European NE BCRADESIGN.COM 11 lotted: V) ~ r.i • II N 0 014 4 M File JUPIT CTS'\_ 245.A iii IN'. I:, I I ~ ~.,,, -,11•c-,c ®' ~ ... ~·'--~;ill+_=:-.''Z ,_-.;"" ....... - --------i. : 11, '1 ~ '..i/11~_., ~! : i ~t-i ./ J ;i °' ,, n f 1 .. 1 Yi.,/ f_ 4-'1''-- i / i ! ., c;, '. i:: I ' I !' ' f1-, if -1 Ii ~ I I ' I ,:11 I ,ii I ;1,/ I :/ Klfl.1 1 i 011, 11·-\a i 1 -1., I I I J1 I I ~ I 1 11 ! • !i I -;-;, __ ,_. i: I i , i'1~- I ! 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CADD FILE us ,,--~ -·---· ---1:r ACC PROJECT: I REVISIONS: --- ACC TACO TIME 4114 N.E. 4TH STREET JJG RENTON, WA 12/18/2013 SHEET TITLE: 13245 WATER QUALITY EXHIBIT (' ,, 562930 47" 2927'N R ; 0 ;;: )Q - 111 562930 Soil Map-King Coun ty A rea , Washington (Taco Time Re nton Highlands) 562990 563050 5631 10 563170 562990 563050 563 110 563170 Map SGlle: 1:2,4 10 if pnnted on A portrait (8S' x 11") sheet . ---------========------------------=================Mete~ 0 35 70 140 210 -----====-------=======::::ifeet 0 100 200 400 600 Map projection: Web Merrate< Comer mordinates: WGS84 Edge tics : lJfM Zone lON WGS84 US DA Natural Resources Web So il Survey Nat ional Cooperative S oi l Survey -riiii Conservation Service 563230 563230 563290 I 111 47' 29' 27'N 0 ; I v, 47" 29'!1"N 563290 12/12/2013 Page 1 of 3 "':4 Soil Map-King County Area. Washington (Taco Time Renton Highlands) MAP LEGEND Al"ea of Interest (AOI) Area of Interest (AOI) Solls L] Soil Map Unit Polygons -Soil Map Unit lines • Soil Map Unit Points Special Point Features ~ Blowout 181 Borrow Pit JI( Clay Spot 0 Closed Depression ;x:; Gravel Pit .. Gravelly Spot 0 Landfill A Lava Flow • Marsh or swamp * Mine or Quarry 0 Miscellaneous Water 0 Perennial Water V Rock Outcrop + Saline Spot Sandy Spot ... Severely Eroded Spot ¢ Sinkhole ~ Slide or Slip pi Sadie Spot Natural Resources r-....... ~ ... rvatinn ,i;:_,,.rviC"' § Spoil Area 0 Stony Spot Gil Very Stony Spot ii' Wei Spot 6 Other .. Special line Features Water Features Streams and Canals Transportation +++ Rails --Interstate Highways US Routes Major Roads Local Roads Background • Aerial Photography Web Soil Survey N .. ti"n"I COO"'"r"'i;,,e Soil C:::,,n,~y MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1 :24,000. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Survey Area Data: King County Area, Washington Version 7, Jul 2, 2012 Soil map units are labeled (as space allows) for map scales 1 :50,000 or larger. Date(s) aerial images were photographed: Jul 9, 2010-Aug 20, 2011 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 12/12/2013 ,..._1e 2 ,..~';I Soil Map-King County Area, Washington Map Unit Legend Map Unit Symbol AgC --·-------- Totals for Area of Interest USDA Natural Resources iiii Conservation Service King County Area, Washington (WA633) Map Unit Name 1 Acres inAOI Alderwood gravelly sandy loam, 6 to 15 percent slopes Web Soil Survey National Cooperative Soil Survey 28 7 28.7 Taco Time Renton Highlands Percent of AOI 100.0% I i 100.0% I 1211212013 Page 3 of3 Section 2 -Conditions and Requirements Summary This project meets the criteria for a Full Drainage Review, per King County Surface Water Design Manual 2009 (SWDM 2009) page 1-11. The application of the eight core requirements and 6 special requirements for the project are outlined below. Core Requirement 111 -Discharge at Natural Location Runoff from the developed site will be captured and conveyed into the existing conveyance system used. This system discharges ultimately to Maplewood Creek. Core Requirement 112 -Of/site Analysis An offsite analysis can be found in Section 3 of this report. Core Requirement 113 -Flow Control This project lies within the Flow Control Duration Standard (Forested Conditions) area. A series of underground detention tanks have been designed to comply with the related flow control requirements. The design and analysis of this system are more thoroughly covered in Section 4 ofthis report. Core Requirement #4 -Conveyance System An analysis of the capacity oft he proposed conveyance system can be found in Section 4 of this report. Core Requirement 115 -Erosion and Sediment Control An Erosion and Sediment Control Plan is not included with this preliminary submittal be will be included with the final submittal. Core Requirement 116 -Maintenance and Operations An Erosion and Sediment Control Plan is not included with this preliminary submittal be will be included with the final submittal. Core Requirement 117 -Financial Guarantees and Liability Financial Guarantees and Liability is not addressed with this preliminary submittal and will be addressed with the final submittal. Core Requirement 118 -Water Quality BCRADESIGN.COM 17 Water Quality standards are achieved through the usage of Storm Filter cartridges located onsite. The design and analysis oft his system are covered in Section 4 of this report. Special Requirement #1 -Other Adopted Area-Specific Requirements To our knowledge the project site is not located in any areas with specific requirements other than those addressed in this report. Special Requirement #2 -Flood Hazard Area Delineation As this project is not located in or adjacent to the 100 year flood plain this requirement is not applicable to this project and is not addressed. Special Requirement #3 -Flood Protection Facilities This requirement is not applicable to this project and is not addressed. Special Requirement #4 -Source Control This requirement is not applicable to this project and is not addressed. Special Requirement #5 -Oil Control This project site is not considered a high use site therefore; this requirement is not applicable to this project and will not be addressed. Special Requirement #6 -Aquifer Protection Area The project site is located within Zone 2 of the APA, as defined by the Renton Muncipal Code (RMC) 4-3-050. Application of these requirements are addressed in Section 4 ofthis report. BCRADESIGN.COM 18 !iii CD n ;;o > Section 3 -Offsite Analysis A Level 1 Analysis of the downstream conditions has been completed, per Core Requirement #2, Section 1.2.2 ofthe 1998 SWDM. As required both the downstream and upstream conditions were analyzed qualitatively for this submission. Upstream Analysis The project site does not receive any water from any offsite source and therefore no upstream tributary area was analyzed. Level 1 Downstream Analysis Runoff from this site enters the Maplewood Creek, see Section 1 of this report for further details concerning onsite conveyance of stormwater runoff. Conveyed through a 36" CMP pipe the stormwater reaches an outfall in Maplewood Creek. The creek is designated as a Class 4 creek and flows south for roughly 2,100 feet. Passing through a 42" CMP Culvert the stream crosses under Bremerton Pl NE and is reclassified as a Class 3 creek. The creek then continues to flow south for another 2,SOO feet before joining with a second branch of Maplewood Creek. The creek is then once again reclassified as a class 2 Creek. The creek further discharges to Cedar River and ultimately to Lake Washington. Though there are reported drainage complaints downstream of the project site none of the complaints are within X mile of the project site. None of the complaints are in any way associated with or connected to drainage features that affect or would be affected by the proposed redevelopment. A map of the complaints and a list of complaints is provided in Task 2 of this section. The site is also fully encompassed in a zone of sensitive area designated for medium susceptibility to groundwater contamination, as shown in the map provided by King County's iMap services. The proposed redevelopment should pose no groundwater contamination concerns. A field investigation has not yet been done for this preliminary submittal but will be completed and provided with the final submittal. BCRADESIGN.COM 19 Task 1-Study Area Definition and Maps BCRADESIGN.COM 20 Taco Time Renton Highlands Legend -, '-County Bound<:! ry ;./ Incorporated Area D Lakes and Large Rivers X Mountai n Peaks Streets ( l .,.-i •. ,· Strea ms Contours {5ft I ight) tfigJiw.,y Shaded Relief 100;500; 1000 r., Artarillls '/"' Oth ar local H'lg.hways Parcels The information included on this map has been compiled by King County staff f rom a variety of sources and is subject to change without notice. King County makes no representations or warranties, express or im plied, as to accuracy. completeness, timeliness, or righls 10 the use of such information. This document is nol intended for u se as a survey product. K ing County s hall nol be liable for any general. special, indirect, incidental, or consequential tQ damages incl uding, but not li mited to, losf revenues or lost profits resulting from the use or misuse of the in formation contained on this map. Any sale of . K ·1ng County this map or informat ion on this map Is proh ibited except by wrillen permission of King County. Date: 12/13/2013 Source : King County iMAP -Sensitive Areas (h ttp://www.metrokc.gov/GIS/iMAP) Task 2 -Resource Review BCRADESIGN.COM 22 jC) 2008 IOng CO<Jnty The inform ation included on this map has been compiled by King County staff from a variety of sources and 1s subject to change without notice. K ing County makes no representations or warranties, express or implied, as to accu racy, completeness, timeliness, or rights 10 the use of such information. This document is not intended for use as a survey product. King County shall not be liable ior any general, special, indirect, incidental. or consequential damages including, but not limited 10, lost revenues or lost profits resulting from the use o r m isuse of the information contained on th is map. Any sale oi this map or information on this map is prohibned excepf by written permiss ion of King County. Date: 12/1312013 Source: King County iMAP • Sensrtive Areas (http://www.metrokc.gov/G IS/1MAP) ~ King County Taco Time Renton Highlands Legend -, County Boundary . . . Undnsifiad Low I_ . X Mountain Peaks D Lakes and Large Rivers Mod ium Coniours (5ft light) /',/ Streams • Hig'h 100; 500: 1000 Channel Migration Hazard Shaded Relief OUiar Areas Highways • MODERATE _I./ Incorporated Area Ill S£'IIIER£ Streets m Sole Source Aquifer Highway m SAO Wetland r,,. Mari:ds 1%8) SAO Landslide .. ,.... L• Local ffl SAO Coa I Mine Parcels ~ SAO Seismic .. Wildlife Network • SAO Erosion SAO Stream ~ Chinook Distribution ;I Clan1 • Sensitive Area Notice on Title // Cbn2Porannill1 Drainage Complaints // Cbn 2 Salmon.id Areas Sus ceptible to ~·· ....... ... C&a-33 Groundwater Contamination (cont) (cont) The information included on this map has been compiled by King County s1aff from a variety of sources and is subject to change without notice. King County makes no representations or warranties, express or imp lied, as to accuracy, comple1eness, 1imeliness. o r rights to !he use of such information. T his document is no! intended for use as a survey product. King County sh all not be liab le for any general, special, indirect. incidental, or consequential w damages including, but not limited to, lost revenues or los1 profits resulting from the use or misuse of the informa1ion contained on this map. Any sale of . K·1ng County this map or information on this map is prohibited except by wrillen permission of King County. Date: 12/1312013 Source: King County ,MAP -Sensitive Areas (http://www.metrokc.gov/GIS/iMAP) Table 3-1: King County Drainage Complaints (Current as of 12/13/2013) Rec Complaint Problem Rec Date PIN No Address 1 1986-1231 RD 12/3/1986 165 Bremerton Pl NE 2525500360 2 1987-0456 DVR 3/16/1987 170 Whitman Ct NE 2525500460 3 2006-0081 OLE 1/17/2006 13715 139th Ave SE 3276150070 4 1978-0070 EROSION 10/2/1978 13901 139th Ave SE 3276150140 5 1990-1020 DRNG 6/4/1990 13732 SE 14151 ST 5127000360 6 1991-0883 FLOODING 8/5/1991 13732 SE 14151 ST 5127000360 7 1991-0883 FLOODING 8/5/1991 13732 SE 14151 ST 5127000360 8 2012-0467 DES 6/14/2012 327615TRCT BCRADESIGN.COM 25 NE1'1"MST \ ~ arH sr ·~ ' Taco Time Renton Highlands NE ,n~sr NE lctTM ST I 0 I N£7THST i % "' NEffTMST PROJECT SITE SE3RDST ,, C: z ~ '> :~ NE 1ctTMST NE9THPl II ... z ~I <OC .= i i "' NE4aiCT I .., ! ;--NE ~T H ~!_ <( I O • t.lE3RDST Q• ~. ii ... .., z t,j z rs! rs! I t i i w z :!i ; SE 132NOST SE2M>ST SE 138THPl S5TlU~ + SE 180T'H ST SE 162NDST SE 164THST 4C) 2008 K111g County w ~I :c .... ~ - +I SE ·100TH P\. -SE 1 -1 I_ County Boundary X Mountain Peaks Hi ghway s Streets {cont) 0 Legend Hig.hw.,y ,.., rv Artarials (: ...... local D Lakes and Large Rivers .,...···~) Streams SE 14'TlfST SE 158'THST SE 159'T"4 Pl. SE 16:!NOFI. 2273ft D 100 Year Floodpla .in The information included on this map has been compiled b y K ing County staff fr om a variety of sources and 1s sub ject to change without no1ice. K ing County makes no representati ons or warranties. express or implied. as to accuracy, completen ess, timeliness, or rights to the use of such information. Th is document 1s not intended for use as a survey product. King County shall not be liable for any general, special, indirect. incidental, or consequential ti damages includi ng, but not limited 10, lost reven ues or lost p rofit s resu lting from the use o r misuse of the information contained on this map. Any sale of . K·1ng County this map or inform ation on this map is prohibited except b y written permiss ion of K ing County. Date: 12/13/20 13 Source: King County iMAP • Sens~ive Areas (http://www.metrokc.gov/G IS/iMAP) Task 3 -Field Inspection A field investigation has not yet been done for this preliminary submittal but will be completed and provided with the final submittal. Task 4 -Drainage System Description and Problem Descriptions Upon completion ofthe field investigation the Drainage System Description and Problem Description will be completed and provided with the final submittal. Task 5 -Mitigation of Existing or Potential Problems Upon completion of the field investigation the Mitigation of Existing or Potential Problems will be completed and provided with the final submittal. BCRADESIGN.COM 27 l!!I to C"I ;:o > Section 4 -Flow Control and Water Quality Facility Analysis and Design Existing Site Hydrology (Part A} In the existing condition the site consists of a single commercial building and the associated commercial features such as parking and landscaping. The pervious areas onsite consist almost exclusively of maintained grass areas. The impervious areas consist of roof tops and impermeable paving. The parcel has a total area of 0. 77 acres. The parcel naturally slopes towards the southeast corner of the site. Runoff generated onsite is conveyed off the site in two areas, both of which discharge to Maplewood Creek within Y. mile downstream. There are also no areas that are tributary to the project site. The site is underlain by soil type AgC, Alderwood gravelly sandy loam with 6-15% slopes. KCRTS categorizes the AgC soil type as part of the Till Soil Group. The rainfall region and scale factor applicable to the project site is SeaTac 1.0. Though the existing site is not in a forested condition the existing hydrologic condition was assumed to be in a forested condition as the site is found in the Flow Control Duration Standard (Forested Conditions) zone. Developed Site Hydrology (Part B} In the proposed redeveloped condition the site consists of two commercial buildings and the associated commercial features, such as parking and landscaping. Due to constraints on all four sides of the project general topography will largely mimic the existing condition. Though the site layout and configuration will change with the redevelopment natural drainage paths will be kept largely unchanged. Site soils are AgC, Alderwood gravelly sandy loam with 6-15% slopes. KCRTS categorizes the AgC soil type as part of the Till Soil Group. The rainfall region and scale factor applicable to the project site is SeaTac 1.0. The developed site consists of a single basin with a single flow control facility, an underground detention system. Because the flow control facility receives runoff from drive aisles in the onsite parking, which is classified as pollution generating surfaces (PGIS), that water is treated for water quality through the use of two stormfilters located onsite. Flow control is provided through the use of a detention system. Performance Standard (Part C} Runoff generated from the developed site is not fully dispersed and therefore will be controlled in accordance with the SWDM 2009. The project site is located within the Flow Control Duration Standard (Forested Condition) zone. Runoff generated onsite will experience sheet flow to onsite BCRADESIGN.COM 28 catch basins being then routed to an underground detention facility before leaving the site. No BMP credits are used on this project therefore 100% of the contributing impervious areas were used in the design of the detention 100% of the pollution generating surfaces were used in the design of the water quality systems. Detention sizing was completed using KCRTS. Site soils are AgC, Alderwood sandy gravely loam with 6-15% slopes and are categorized by KCRTS in the Till Soil Group. The rainfall region and scale factor is SeaTac 1.0. The onsite detention system was designed such that the peak flows leaving the site were less than predeveloped (forested condition) peak flow rates ranging from 50% of the 2 year storm event up to the 50 year storm event. Runoff to be treated for water quality will be collected and treated by one of two stormfilter cartridges located in-line with the onsite stormwater conveyance system. Water drained from the drive aisles will be routed to these two filters while the two proposed structures roofs will be constructed from materials treated to prevent leaching and therefore are considered as non- pollution generating surfaces. Flow Control System (Part D) Details and plans showing the location and orientation of the underground detention facility can be found at the end of this section. The following calculations were done in KCRTS to size the underground detention facility for the project site. Table 4-1: KCRTS Input Areas Areas Area Land Use Impervious Area Pervious Area (ac) Type (ac) (ac) > Cl/ 0.78 Forest 0.00 0.78 0 --0.00 0.00 Cl/ L 0.. Total 0.00 0.78 > 0.66 Impervious 0.66 0.00 Cl/ 0 0.12 Till Grass 0.00 0.12 ~ "' 0 Total 0.66 0.12 0.. BCRADESIGN.COM 29 Bil tD () ;:o )> Retention/Detention Facility Type of Facility: Detention Tank Tank Diameter: 6. 00 ft Tank Length: Effective Storage Depth: Stage O Elevation: Storage Volume: Riser Head: Riser Diameter: Number of orifices: Orifice# 1 2 Height (ft) 0.00 3.00 500.00 5.50 0.00 13574. 5.50 12.00 2 Diameter (in) 0.44 0.90 Top Notch Weir: None Outflow Rating Curve: None Stage (ft) 0.00 0.01 0.02 0.03 0.04 0.14 0.24 0.34 0.44 0.54 0.64 0.74 0.84 0.94 1. 04 1. 14 1. 24 1. 34 1. 44 1. 54 1. 64 1. 74 1. 84 1. 94 2.04 2.14 2.24 2.34 2.44 Elevation (ft) 0.00 0.01 0.02 0.03 0.04 0.14 0.24 0.34 0.44 0.54 0.64 0.74 0.84 0.94 1. 04 1.14 1. 24 1. 34 1. 4 4 1. 54 1. 64 1. 7 4 1. 84 1. 94 2.04 2.14 2.24 2.34 2.44 Storage (cu. ft) 0. 17. 34. 50. 68. 246. 438. 640. 854. 107 6. 1308. 1547. 1793. 204 6. 2306. 2570. 2840. 3115. 3393. 367 6. 3962. 4251. 4542. 4836. 5131. 542 9. 5727. 602 6. 632 6. ft ft ft cu. ft ft inches Full Head Pipe Discharge (CFS) 0.012 0.035 Diameter (in) Discharge (ac-ft) (cfs) 0.000 0.000 0.000 0.001 0.001 0.002 0.006 0.010 0.015 0.020 0.025 0.030 0.036 0.041 0.047 0.053 0.059 0.065 0.072 0.078 0.084 0.091 0.098 0.104 0 .111 0.118 0.125 0.131 0.138 0.145 0.001 0.001 0.001 0.001 0.002 0.003 0.003 0.003 0.004 0.004 0.005 0.005 0.005 0.005 0.006 0.006 0.006 0.006 0.007 0.007 0.007 0.007 0.007 0.007 0.008 0.008 0.008 0.008 4.0 Percolation (cfs) 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 BCRADESIGN.COM 30 l!'il tD () ;ti > 1!11 IXI () ;c )> 2.54 2.54 662 6. 0.152 0.008 0.00 2.64 2.64 692 6. 0.159 0.009 0.00 2.74 2.74 7225. 0.166 0.009 0.00 2.84 2.84 7524. 0.173 0.009 0.00 2.94 2.94 7821. 0.180 0.009 0.00 3.00 3.00 7999. 0.184 0.009 0.00 3.01 3.01 802 9. 0.184 0.009 0.00 3.02 3.02 8058. 0.185 0.010 0.00 3.03 3.03 8088. 0.186 0. 011 0.00 3.04 3.04 8117. 0.186 0.012 0.00 3.05 3.05 8147. 0.187 0. 013 0.00 3.06 3.06 8176. 0.188 0.014 0.00 3.07 3.07 8206. 0.188 0.015 0.00 3.08 3.08 8235. 0.189 0.015 0.00 3.18 3.18 8528. 0 .196 0.019 0.00 3.28 3.28 8819. 0.202 0.021 0.00 3.38 3.38 9108. 0.209 0.023 0.00 3.48 3.48 9393. 0.216 0.025 0.00 3.58 3.58 9675. 0.222 0. 027 0.00 3.68 3.68 9952. 0.228 0.028 0.00 3.78 3.78 10226. 0.235 0.030 0.00 3.88 3.88 10495. 0.241 0.031 0.00 3.98 3.98 10759. 0.247 0.032 0.00 4.07 4.07 10991. 0.252 0.033 0.00 4.17 4 .17 11244. 0.258 0.035 0.00 4.27 4.27 11489. 0.264 0.036 0.00 4.37 4.37 11728. 0.269 0.037 0.00 4.47 4.47 11958. 0.275 0.038 0.00 4.57 4.57 12180. 0.280 0.039 0.00 4.67 4.67 12392. 0.284 0.040 0.00 4. 77 4.77 12594. 0.289 0.041 0.00 4.87 4.87 12784. 0.293 0.042 0.00 4.97 4.97 12961. 0. 298 0.043 0.00 5.07 5.07 1312 4. 0.301 0.043 0.00 5.17 5.17 13270. 0.305 0.044 0.00 5. 27 5.27 13396. 0.308 0.045 0.00 5.37 5.37 13498. 0.310 0.046 0.00 5.47 5.47 13566. 0. 311 0.047 0.00 5.50 5.50 13574. 0.312 0.047 0.00 5.60 5.60 13574. 0.312 0.356 0.00 5.70 5.70 13574. 0.312 0.920 0.00 5.80 5.80 13574. 0.312 1.650 0.00 5.90 5.90 13574. 0.312 2.440 0.00 6.00 6.00 13574. 0.312 2.730 0.00 6.10 6.10 13574. 0.312 2.980 0.00 6.20 6. 20 13575. 0.312 3.220 0.00 6.30 6.30 13575. 0.312 3.440 0.00 6.40 6.40 13575. 0.312 3.640 0.00 6.50 6.50 13575. 0.312 3.840 0.00 6.60 6.60 13575. 0.312 4.020 0.00 6.70 6.70 13575. 0.312 4. 200 0.00 6.80 6.80 13575. 0.312 4.370 0.00 BCRADESIGN.COM 31 6.90 6.90 13575. 0.312 4.530 0.00 7.00 7.00 13575. 0.312 4.690 0.00 7.10 7.10 13575. 0.312 4.840 0.00 7.20 7.20 13575. 0.312 4. 9 90 0.00 7.30 7.30 13575. 0.312 5.130 0.00 7.40 7.40 13575. 0.312 5.270 0.00 7.50 7.50 13575. 0.312 5.410 0.00 Hyd Inflow Outflow Peak Storage Target Cale Stage Elev (Cu-Ft) (Ac-Ft) 1 0.34 ******* 0.04 5.18 2 0.24 ******* 0.01 2.66 3 0.21 ******* 0.01 1. 82 4 0.20 ******* 0.01 1. 51 5 0.18 ******* 0.02 3.19 6 0.17 ******* 0.04 4.54 7 0 .17 ******* 0.01 2.15 8 0.15 ******* 0.02 3.09 ---------------------------------- Route Time Series through Facility Inflow T irne Series File:ttpost.tsf Outflow Time Series File:rdout Inflow/Outflow Analysis Peak Inflow Discharge: Peak Outflow Discharge: Peak Reservoir Stage: Peak Reservoir Elev: 0.337 0.044 5.18 5.18 5.18 2.66 1. 82 1. 51 3.19 4.54 2.15 3.09 CFS at CFS at Ft Ft Peak Reservoir Storage: 13285.Cu-Ft 0.305 Ac-Ft 13285. 6984. 4485. 3594. 8571. 12106. 5468. 8279. 6:00 on 14:00 on Flow Duration from Time Series File:rdout.tsf 0.305 0.160 0.103 0.082 0.197 0.278 0. 126 0.190 Jan 9 in Jan 9 in Cutoff Count Frequency CDF Exceedence Probability CFS % % % 0.001 25225 41.137 41.137 58.863 0.589E+OO 0.002 6621 10.797 51.934 48.066 0.481E+OO 0.003 8491 13.847 65.781 34.219 0.342E+OO 0.004 4035 6.580 72. 3 61 27.639 0.276E+OO 0.006 6510 10.616 82.978 17.022 0.170E+OO 0.007 3538 5.770 88.748 11.252 0. 113E+OO 0.008 32 97 5.377 94.124 5.876 0.588E-01 0.009 3113 5.077 99.201 0.799 0.799E-02 0.010 26 0.042 99.243 0.757 0.757E-02 0.012 32 0.052 99. 2 96 0.705 0.705E-02 0.013 25 0.041 99.336 0. 664 0.664E-02 0.014 16 0.026 99.362 0.638 0.638E-02 0.015 28 0.046 99.408 0. 5 92 0.592E-02 0.016 40 0. 065 99.473 0.527 0.527E-02 0.018 31 0.051 99.524 0.476 0.476E-02 0.019 29 0.047 99.571 0.429 0.429E-02 Year Year 8 8 BCRADESIGN.COM 32 liil tD n ::0 )> 0.020 44 0. 072 99.643 0.357 0.357E-02 0. 021 35 0.057 99.700 0.300 0.300E-02 0.022 28 0.046 99.746 0.254 0.254E-02 0.024 15 0.024 99.770 0.230 0.230E-02 0.025 12 0.020 99.790 0.210 0.210E-02 0.026 9 0.015 99.804 0 .196 0.196E-02 0.027 7 0. 011 99.816 0.184 0.184E-02 0.028 12 0.020 99.835 0.165 0.165E-02 0.030 8 0.013 99.848 0.152 0.152E-02 0.031 15 0.024 99.873 0.127 0 .127E-02 0.032 15 0.024 99.897 0.103 0.103E-02 0.033 14 0.023 99.920 0.080 0.799E-03 0.034 4 0.007 99.927 0.073 0.734E-03 0.036 9 0.015 99.941 0.059 0.587E-03 0.037 8 0.013 99.954 0.046 0.457E-03 0.038 10 0.016 99.971 0.029 0.294E-03 0.039 2 0.003 99.974 0.026 0.261E-03 0.040 3 0.005 99.979 0. 021 0.212E-03 0.042 3 0.005 99.984 0.016 0.163E-03 0.043 4 0.007 99.990 0.010 0.978E-04 Duration Comparison Anaylsis Base File: ttpre.tsf New File: rdout.tsf Cutoff Units: Discharge in CFS -----Fraction of Time--------------Check of Cutoff Base New %Change Probability Base 0.010 O.lOE-01 0.75E-02 -27. 2 O.lOE-01 0.010 0. 013 0.66E-02 0.65E-02 -1. 7 0.66E-02 0.013 0.016 0.SOE-02 0.53E-02 4.2 0.50E-02 0.016 0.019 0.39E-02 0.39E-02 2.1 0.39E-02 0.019 0.022 0.30E-02 0.25E-02 -13. 8 0.30E-02 0.022 0.025 0.22E-02 0.20E-02 -9.5 0.22E-02 0.025 0.028 0.15E-02 0 .16E-02 8.6 0 .15E-02 0.028 0.031 O.lOE-02 O.llE-02 9.4 O.lOE-02 0.031 0.034 0.62E-03 0.73E-03 18.4 0.62E-03 0.034 0.037 0.34E-03 0.38E-03 9.5 0.34E-03 0.037 0.040 0.23E-03 0. 21E-03 -7.1 0.23E-03 0.040 0.043 0.16E-03 0.33E-04 -80.0 0.16E-03 0.043 0.046 0. llE-03 O.OOE+OO -100.0 0. llE-03 0.046 0.049 0.16E-04 O.OOE+OO -100.0 0.16E-04 0.049 Maximum positive excursion= 0.001 cfs 6.8%) occurring at 0.014 cfs on the Base Data:ttpre.tsf and at 0.015 cfs on the New Data:rdout.tsf Maximum negative excursion= 0.003 cfs (-23.6%) occurring at 0.012 cfs on the Base Data:ttpre.tsf and at 0.009 cfs on the New Data:rdout.tsf Route Time Series through Facility Tolerance------- New %Change 0.009 -13.5 0.013 -3.5 0.017 3.2 0.020 1. 1 0.021 -5.0 0.024 -6.1 0.030 4.3 0.032 1. 3 0.035 3.4 0.037 0.2 0.040 -0.9 0.042 -3.9 0.043 -7.9 0.044 -11. 4 BCRADESIGN.COM 33 !!ii CD () ,IJ > r; tD C"'I ;a )> Inflow Time Series File:ttpost.tsf Outflow Time Series File:rdout Inflow/Outflow Analysis Peak Inflow Discharge: 0.337 CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge: 0.044 CFS at 14:00 on Jan 9 in Year 8 Peak Reservoir Stage: 5.18 Ft Peak Reservoir Elev: 5.18 Ft Peak Reservoir Storage: 13285. Cu-Ft 0.305 Ac-Ft Flow Duration from Time Series File:rdout.tsf Cutoff Count Frequency CDF Exceedence Probability CFS % % % 0.001 25225 41.137 41.137 58.863 0.589E+OO 0.002 6621 10.797 51.934 48.066 0.481E+OO 0.003 8491 13.847 65.781 34.219 0.342E+OO 0.004 4035 6.580 72. 3 61 27.639 0.276E+OO 0.006 6510 10.616 82.978 17. 022 0.170E+OO 0.007 3538 5. 770 88.748 11. 252 0 .113E+OO 0.008 32 97 5.377 94.124 5.876 0.588E-01 0.009 3113 5.077 99.201 0.799 0.799E-02 0.010 26 0.042 99.243 0.757 0.757E-02 0.012 32 0.052 99.296 0.705 0.705E-02 0. 013 25 0.041 99.336 0.664 0.664E-02 0.014 16 0.026 99.362 0.638 0.638E-02 0.015 28 0.046 99.408 0.592 0.592E-02 0.016 40 0.065 99. 4 73 0. 527 0. 527E-02 0.018 31 0.051 99.524 0.476 0.476E-02 0.019 29 0.047 99.571 0.429 0.429E-02 0.020 44 0.072 99.643 0.357 0.357E-02 0.021 35 0.057 99.700 0.300 0.300E-02 0.022 28 0.046 99.746 0.254 0.254E-02 0.024 15 0.024 99.770 0.230 0.230E-02 0.025 12 0.020 99.790 0. 210 0.210E-02 0.026 9 0.015 99.804 0 .196 0.196E-02 0. 027 7 0. 011 99.816 0.184 0.184E-02 0.028 12 0.020 99.835 0.165 0.165E-02 0.030 8 0. 013 99.848 0.152 0.152E-02 0.031 15 0.024 99.873 0.127 0.127E-02 0.032 15 0.024 99.897 0.103 0.103E-02 0.033 14 0.023 99.920 0.080 0.799E-03 0.034 4 0.007 99. 927 0.073 0.734E-03 0.036 9 0.015 99.941 0.059 0.587E-03 0.037 8 0. 013 99.954 0.046 0.457E-03 0.038 10 0.016 99. 971 0.029 0.294E-03 0.039 2 0.003 99.974 0.026 0.261E-03 0.040 3 0.005 99.979 0. 021 0.212E-03 0.042 3 0.005 99.984 0.016 0.163E-03 0.043 4 0.007 99.990 0.010 0.978E-04 BCRADESIGN.COM 34 00 lL u ~ a, 2' .. .c " "' i5 Figure 4-1: Duration Analysis Plat "' C! 0 ,,__ __ --==~- • -~, c!'i-1----------~-------o e') 0 0 "' 0 0 +, I<) :+\ '• \ • '\+., rdoutdur TTPostTar dur • 00------------------\--'+' -------------- 0 0 o O•-~~~~~-~-~~~=---~~~=-~~-~~--~-~~~ 10 ·5 10 -4 10 -3 10 _, 10 ·1 10° Probab1l1ty Exceedence Water Quality System (Part E) The water quality requirements for this project are achieved through the usage of Storm Filters. Two Storm Filter manholes are proposed on the project site, one near the northeast corner and one along the southern edge of the project. Details for these units can be found at the end of this section and a plan showing the location and orientation of these filters can be found in Figure 1-3 on page 12. These two Storm Filter manholes filter runoff prior to detention in the underground detention system, sized in Part C above. As they filter prior to detention they are designed to treat 60% of the 2 year storm event runoff generated from the developed condition. KCRTS was used to determine peak flows used for the Storm Filter sizing. The calculations for the North Filter and South Filter can be found below. BCRADESIGN.COM 35 Table 4-2: Water Quality Areas Impervious Area Pervious Area Name (sf) (ac) (sf) (ac) North Filter 9,027 0.207 1,249 0.029 South Filter 10,633 0.244 2,567 0.059 North Filter Flow Frequency Analysis Time Series File:ttwqn.tsf Project Location:Sea-Tac ---Annual Peak Flov Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak -Peaks --Rank Return Prob (CFS) (CFS) Period 0.099 6 8/27/01 18 :DO 0.259 1 100.00 0. 990 0. 069 8 9/17/02 17 :45 0.193 2 25.00 0. 960 0.193 2 12/08/02 17: 15 0.135 3 10.00 0. 900 0. 079 7 8/2 3/04 14: 30 0 .112 4 5.00 0. 800 0.106 5 10/28/04 16: 00 0.106 5 3.00 0. 667 0 .112 4 10/27/05 10: 45 0.099 6 2.00 0 . 500 0 .135 3 10/25/06 22: 45 0 . 079 ? 1 .30 0. 231 0 .259 1 l/09/08 6: 30 0 . 069 8 1 10 0. 091 Computed Peaks 0 . 237 50. 00 0. 980 Owo = 0.60*G.i = (0.60)*(0.099 cfs) = 0.059 cfs Number of Filters= Owo/Ofi1ter = (0.059 cfs)/(7.5 gpm/449) = 4 Cartridges South Filter Flow Frequency Analysis Time Series File:ttwqs.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates-~ -----Flow Frequency Analysis------- Flow Rate Rank Time of Peak -Peaks Rank Return Prob (CFS) (CFS) Period 0 .116 6 8/27/01 18:00 0.317 1 100.00 0 .990 0.081 8 9/17/02 17:45 0.233 2 25.00 0 . 960 0. 233 2 12/08/02 17:15 0.160 3 10.00 0 .900 0.094 7 8/23/04 14:30 0.134 4 5 .DO 0 .800 0.126 5 10/28/04 16:00 0.126 5 3 .OD 0 .667 0.134 4 10/27/05 10:45 0 .116 6 2 . oo I 0 .500 0.160 3 10/25/06 22:45 0.094 7 1 .30 0 .231 0.317 1 l/09/08 6:30 0.081 8 1 .10 0. 091 Computed Peaks 0.289 so . 00 0. 980 Owo = 0.60*G.i =(0.60)*(0.116cfs) = 0.070 cfs Number of Filters= Owo/D.r;1,e, = (0.070 cfs)/(7.5 gpm/449) = 5 Cartridges BCRADESIGN.COM 36 Inlet pipe I""_,,,_, where alowed) A t.. -0 0.90" DIAM ORIFICE ELEV: 390.62' NOTB: control stn.dura (FROP-T shown) min. 54• cla. Type2CB _l_ 2'.,., AU melal parts corrosion resistant. Steel parts galvanized end asphalt coaled (Treatment 1 or better) PUBLIC WORKS DEPARTMENT .-----~ opuona1para11e11ank _ I 'l /--, \ I // ' I I IICC8S8 nams r -7 \ I ,,--r --------, I l)(_ (max,pacl"9ahown-D I 36'" I () \ I .,.,,..,.., I I I I--l / min. diameter L__________________ _ _____ J 1 ,, ...... r 1 .,,.~ sameasinletpipe 125' ] )./ I I 6' access risers PLAN VIEW NTS 'Flow-through" system shown SOid. Designs for "flow backup" system lWld parallel tar*& shown daahed 100'max ...,... .... flow j inlet pipe ("""through) type 2 CB ~Ired for flow thRJU11h system only 2" min. diameter air vent pipe welded to lank (reqwed If no ac:ces1 riser on tar*) TANK BOTTOM ELEV: 387.62' SECTION AA NT8 "Flow-through" system shown solid. TYPICAL DETENTION TANK STD. PLAN -235.00 MARCH 2008 NOTES: standard type 2-60" diem. CB concrele lop slab 36" CMP riser atandard lockq compacted pipe bedding M.H. Bteps 12" 0.C. wald orbol standard M.H. steps 1. Use adjusting blocks as required to bring frame to guide. SECTION NTS 2. All materials to be aluminum or galvanized and asphalt coated (Treatment 1 or better). 3. Must be located for access by maintenance vehlcles. 4. May substitute WSDOT special Type IV manhole (RCP only). frame loclcing lid {marked "DRAIN") mounted ov9' 24" diam. eccentric opening maintain 1" gep belw9en bottom of slab & lop of rlaer. provide ~able gasket to exclude dirt riser. 36"" diam. min., same material & gage as tank welded or fused to tank detention tank PUBLIC WORKS DEPARTMENT DETENTION TANK ACCESS DETAIL STD. PLAN -235.10 MARCH 2008 L "Low --..:. INLET TOP SLAB ACCESS SEE FRAME ANO COVER DETAIL CONTRACTOR TO GROUT TO FINISHED GRADE GRADE RING/RISERS~ INLET PIPE PLAN VIEW STANDARD OUTLET RISER FLOWKff: 42A '//>0vv;~ g ,"- -,-. J. '===' '===' FLOW KIT STORM FILTER CARTRIDGE ( OUTLET SUMP HOPE OUTLET RISER SECTION A-A Th•'--·~"·•-~ Storm Filter· ,..-...., ... ,.-.,cn.·ov~,=~,..-,...,..~ "'""""'"'""'""""""'''""'"" .---"'"'""'""'""''"'"""~"" .. ''·'"''."''"'"" OUTLET SUMP A J OUTLET 72" 1.D. MANHOLE STRUCTURE (86") O.D. FLOATABLES BAFFLE a. . 0 ·> a::~~ o_>-u ... UJ ::::i~~ ::,z::, ;:;:::.o 5= e.g I ... I~ S2 () UJ -I a. w 1: 0 ci3 (0 ;;,; STORMFIL TER DESIGN NOTES STORMFILTER TREATMENTCAPACITY IS A FUNCTION OF THE CARTRIDGE SELECTION AND THE NUMBER OF CARTRIDGES. THE STANDARD MANHOLE STYLE IS SHOWN WITH THE MAXIMUM NUMBER OF CARTRIDGES (7). VOLUME SYSTEM IS ALSO AVAILABLE WITH MAXIMUM 7 CARTRIDGES. 072 MANHOLE STORMFIL TER PEAK HYDRAULIC CAPACITY IS 1.5 CFS. IF THE SITE CONDITIONS EXCEED 1.5 CFS AN UPSTREAM BYPASS STRUCTURE IS REQUIRED. CARTRIDGE SELECTION CARTRIDGE HEIGHT 27" 18" LOW DROP 3.05' 2.3' 1.8' SPECIFIC FLOW RATE (g_e.m/s· 2 gpmlft2 I 1 gpm/ff' 2 gpmlft2 1 gpm/fP 2 gpm/fF 1 gpm/fP CARTRIDGE FLOW RA TE (gpm) 22.s I 11.2s 15 7.5 10 SITE SPECIFIC DATA REQUIREMENTS STRUCTURE ID WATER QUALITY FLOW RATE (els) PEAK FLOW RATE (cfs) RETURN PERIOD OF PEAK FLOW (yrs) # OF CARTRIDGES REQUIRED CARTRIDGE FLOW RATE MEDIA TYPE (CSF, PERLITE, ZPG, GAC, PH$) 5 ·-i .. : PIPE DATA: I.E. MATERIAL DIAMETER INLET PIPE #1 ~'87 8 INLET PIPE #2 OUTLET PIPE "3t'5.5 G" UPSTREAM RIM ELEVATION DOWNSTREAM RIM ELEVATION '.:<95 6 ANTI-FLOTATION BALLAST WIDTH HEIGHT GENERAL NOTES FRAME AND COVER (DIAMETER VARIES) N.T.S. 1. CONTECH TO PROVIDE ALL MATERIALS UNLESS NOTED OTHERWISE. NOTES/SPECIAL REQUIREMENTS: * PER ENGINEER OF RECORD 2. DIMENSIONS MARKED WITH (} ARE REFERENCE DIMENSIONS. ACTUAL DIMENSIONS MAY VARY. 3. FOR SITE SPECIFIC DRAWINGS WITH DETAILED VAULT DIMENSIONS AND WEIGHTS, PLEASE CONTACT YOUR CONTE CH CONSTRUCTION PRODUCTS REPRESENTATIVE. www.contech-cpi.com 4. STORMFILTER WATER QUALITY STRUCTURE SHALL BE IN ACCORDANCE WITH ALL DESIGN DATA AND INFORMATION CONTAINED IN THIS DRAWING. 5. STRUCTURE SHALL MEET AASHTO HS20 AND CASTINGS SHALL MEET AASHTO M306 LOAD RATING, ASSUMING GROUNDWATER ELEVATION AT, OR BELOW, THE OUTLET PIPE INVERT ELEVATION. ENGINEER OF RECORD TO CONFIRM ACTUAL GROUNDWATER ELEVATION 6. FILTER CARTRIDGES SHALL BE MEDIA-FILLED, PASSIVE, SIPHON ACTUATED, RADIAL FLOW, AND SELF CLEANING. RADIAL MEDIA DEPTH SHALL BE 7-INCHES. FILTER MEDIA CONTACT TIME SHALL BE AT LEAST 39 SECONDS. 7. SPECIFIC FLOW RATE IS EQUAL TO THE FILTER TREATMENT CAPACITY (gpm) DIVIDED BY THE FILTER CONTACT SURFACE AREA (sq ft). INSTALLATION NOTES 1. ANY SUB-BASE, BACKFILL DEPTH, AND/OR ANTI-FLOTATION PROVISIONS ARE SITE-SPECIFIC DESIGN CONSIDERATIONS AND SHALL BE SPECIFIED BY ENGINEER OF RECORD. 2. CONTRACTOR TO PROVIDE EQUIPMENT WITH SUFFICIENT LIFTING AND REACH CAPACITY TO LIFT AND SET THE STORM FILTER STRUCTURE (LIFTING CLUTCHES PROVIDED). 3. CONTRACTOR TO INSTALL JOINT SEAL.ANT BETWEEN ALL STRUCTURE SECTIONS AND ASSEMBLE STRUCTURE . 4. CONTRACTOR TO PROVIDE, INSTALL, AND GROUT INLET PIPE(S) 5. CONTRACTOR TO PROVIDE AND INSTALL CONNECTOR TO THE OUTLET RISER STUB. STORMFILTER EQUIPPED WITH A DUAL DIAMETER HOPE OUTLET STUB AND SAND COLLAR. IF OUTLET PIPE IS LARGER THAN B INCHES, CONTRACTOR TO REMOVE THE 8 INCH OUTLET STUB AT MOLDED IN CUT LINE. COUPLING BY FERNCO OR EQUAL AND PROVIDED BY CONTRACTOR. 6. CONTRACTOR TO TAKE APPROPRIATE MEASURES TO PROTECT CARTRIDGES FROM CONSTRUCTION-RELATED EROSION RUNOFF. ~l«::.UT~~U® ~,'ii' .. -... ---.-. !!:'iii" •• Iii~ _,.,, __ CONSTRUCTION PRODUCTS INC. -.contech<pl.com 9025 Centre Pointe Dr., Suite 400, West Chester, OH 45069 800-338-1122 513-645-7000 513-645-7993 FAX SFMH72 STORMFIL TER STANDARD DETAIL l ''<ow --..c INLET TOP SLAB ACCESS SEE FRAME AND COVER DETAIL CONTRACTOR TO GROUT TO FINISHED GRADE GRADE RING/RISERS~ INLET PIPE PLAN VIEW STANDARD OUTLET RISER FLOWKIT, 42A "-//)//)Y/:Y/' "" 1 '</-.....-..... [ . '===' FLOW KIT STORMFIL TER CARTRIDGE OUTLET SUMP HOPE OUTLET RISER SECTION A-A Th• s..,,......,.,. Mana9M1~ StormFilter• __ , ...... -""" ··-~~ .. ~-·«·~ "'"""'' .,,,.,.,.,.,,..,.,...,,-..~ ... ,--- """'""'""""''"'""'"'"'<t>''•"'"""~-. OUTLET SUMP j OUTLET 72" I.D. MANHOLE STRUCTURE (86") O.D. FLOAT ABLES BAFFLE a. . 0 ·> "'>z oz- -f- !:2 tii~ 5 ~!:; ~ ;:;o !; !,8 :c f-:c ~ Qc) w_ :c a. ~~ U) w ~ STORM FILTER DESIGN NOTES STORMFILTER TREATMENTCAPACITY IS A FUNCTION OF THE CARTRIDGE SELECTION AND THE NUMBER OF CARTRIDGES. THE STANDARD MANHOLE STYLE IS SHOWN WITH THE MAXIMUM NUMBER OF CARTRIDGES (7). VOLUME SYSTEM IS ALSO AVAILABLE WITH MAXIMUM 7 CARTRIDGES. 072 MANHOLE STORM FILTER PEAK HYDRAULIC CAPACITY IS 1.5 CFS. IF THE SITE CONDITIONS EXCEED 1.5 CFS AN UPSTREAM BYPASS STRUCTURE IS REQUIRED. CARTRIDGE SELECTION CARTRIDGE HEIGHT 27" 18" LOW DROP RECOMMENDED HYDRAULIC DROP (H) 3.05' 2.3' 1.8' SPECIFIC FLOW RA TE {gpm/s CARTRIDGE FLOW RATE(gpm) 2 gpm/ft2 I 1 9 pm/ff 2 9pmlft' I 1 9pmlft' 2 gpm/ft2 1 gpm!ft2 22.5 I 11.25 15 I 7.5 10 SITE SPECIFIC DATA REQUIREMENTS STRUCTURE ID WATER QUALITY FLOW RATE (cfs) PEAK FLOW RATE (cfs) RETURN PERIOD OF PEAK FLOW (yrs) # OF CARTRIDGES REQUIRED CARTRIDGE FLOW RA TE MEDIA TYPE (CSF, PERLITE, ZPG, GAG, PHS) 5 :<.,'~; .,{(_) ,· ·-,c-r·,I PIPE DATA: I.E. MATERIAL DIAMETER INLET PIPE #1 3UO 4 INLET PIPE #2 OUTLET PIPE ~'>88 I UPSTREAM RIM ELEVATION 3:,_;·_. DOWNSTREAM RIM ELEVATION ·.g4 :, ANTI-FLOTATION BALLAST WIDTH HEIGHT GENERAL NOTES FRAME AND COVER (DIAMETER VARIES) N.T.S. 1. CONTECH TO PROVIDE ALL MATERIALS UNLESS NOTED OTHERWISE NOTES/SPECIAL REQUIREMENTS, ' PER ENGINEER OF RECORD 2. DIMENSIONS MARKED WITH () ARE REFERENCE DIMENSIONS. ACTUAL DIMENSIONS MAY VARY. 3. FOR SITE SPECIFIC DRAWINGS WITH DETAILED VAULT DIMENSIONS AND WEIGHTS, PLEASE CONTACT YOUR CONTECH CONSTRUCTION PRODUCTS REPRESENTATIVE www.contech-cpi.com 4. STORMFIL TER WATER QUALITY STRUCTURE SHALL BE IN ACCORDANCE WITH ALL DESIGN DATA AND INFORMATION CONTAINED IN THIS DRAWING. 5. STRUCTURE SHALL MEET AASHTO HS20 AND CASTINGS SHALL MEET AASHTO M306 LOAD RATING, ASSUMING GROUNDWATER ELEVATION AT, OR BELOW, THE OUTLET PIPE INVERT ELEVATION. ENGINEER OF RECORD TO CONFIRM ACTUAL GROUNDWATER ELEVATION 6. FILTER CARTRIDGES SHALL BE MEDIA-FILLED, PASSIVE, SIPHON ACTUATED, RADIAL FLOW, AND SELF CLEANING. RADIAL MEDIA DEPTH SHALL BE 7-INCHES. FILTER MEDIA CONTACT TIME SHALL BE AT LEAST 39 SECONDS. 7. SPECIFIC FLOW RATE IS EQUAL TO THE FILTER TREATMENT CAPACITY (gpm) DIVIDED BY THE FILTER CONTACT SURFACE AREA (sq ft). INST ALLA TJON NOTES 1. ANY SUB-BASE, BACKFILL DEPTH, AND/OR ANTI-FLOTATION PROVISIONS ARE SITE-SPECIFIC DESIGN CONSIDERATIONS AND SHALL BE SPECIFIED BY ENGINEER OF RECORD. 2. CONTRACTOR TO PROVIDE EQUIPMENT WITH SUFFICIENT LIFTING AND REACH CAPACITY TO LIFT AND SET THE STORMF!L TER STRUCTURE (LIFTING CLUTCHES PROVIDED). 3. CONTRACTOR TO INSTALL JOINT SEALANT BElWEEN ALL STRUCTURE SECTIONS AND ASSEMBLE STRUCTURE. 4. CONTRACTOR TO PROVIDE, INSTALL, AND GROUT INLET PIPE(S). 5. CONTRACTOR TO PROVIDE AND INSTALL CONNECTOR TO THE OUTLET RISER STUB. STORMFILTER EQUIPPED WITH A DUAL DIAMETER HOPE OUTLET STUB AND SAND COLLAR. IF OUTLET PIPE IS LARGER THAN B INCHES, CONTRACTOR TO REMOVE THE 8 INCH OUTLET STUB AT MOLDED IN CUT LINE. COUPLING BY FERNCO OR EQUAL AND PROVIDED BY CONTRACTOR. 6. CONTRACTOR TO TAKE APPROPRIATE MEASURES TO PROTECT CARTRIDGES FROM CONSTRUCTION-RELATED EROSION RUNOFF. ~~l~UTr~U® ~~ .. -.---.-. i:ii" •• Ii ~ _._,, -- CONSTRUCTION PROOUCTS INC. www.contech-cpl.com 9025 Centre Pointe Dr., Suite 400, West Chester, OH 45069 ··-------------·--·----aoo-331S--11:.!:.! 513-645-7000 513-645-7993 FAX SFMH72 STORM FILTER STANDARD DETAIL Section 5 -Conveyance System Analysis and Design Onsite The proposed site conveyance system is comprised of an underground detention system and a network of pipes to convey to and from the underground detention system. Catch basins collect the sheet flow from the site and convey the runoff into the underground detention system, see Section 4 of this report for the sizing of that system. After the stormwater exists the underground detention system it flows south across N.E. 4th Street and to an outfall in Maplewood Creek. The pipes located onsite were sized by sizing the pipe in the worst case scenario and applying this sizing to each other pipe in the system. This scenario involves the project's minimum pipe size, 8 inch diameter pipe, and the minimum slope, 0.0079 ft/ft. For preliminary design purposes the Uniform Flow Analysis Method was used while final design will also incorporate the Backwater Analysis Method. The calculation for this sizing is shown below. Note that the entire area tributary to the pipe in this calculation was assumed to be impervious to provide the worst case scenario. Figure 5-1: Conveyance Sizing Areas f) land U:se Area I= I - -Land Use Type ---------j Area (acres Till Forest 10.000 Till Pasture j0.000 Till Gross j0.000 Outwash Forest 10.000 Outwash Pasture jo.ooo Outwash Grass ID.ODO Weffand j0.000 Impervious _j0.370 Scale Factor 11.000 I i Time Step I !r Hourly r. 15-minute I Data Type I r. Reduced r Historic -------------- Compute Total Area I I Enter area for this land use type~ ojfif i•u)N-E BCRADESIGN.COM 41 Flow Frequency Analysis Time Series File:ttconveyon.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--- Flow Rate Rank (CFS) 0.176 0.123 0.333 0.142 0.187 0.197 0.239 0.436 Computed Peaks Q = Flowrate (cfs) n = Mannings Coefficient r = Pipe Radius (ft) 6 8 2 7 s 4 3 1 Time of 8/27/01 9/17/02 12/08/02 8/23/04 10/28/04 10/27/05 10/25/06 l/09/08 A= Cross Sectional Area of Pipe (ft 2) P = Wetted Perimeter (ft) R = Hydraulic Radius (ft) S = Slope of Pipe (ft/ft) Ois = 0.333 cfs Otu11 = (1.49/n)AR2;3s1;2 r = 0.33 ft n = 0.014 A= rr*r2 = 0.35 ft 2 P = 2*rr*r = 2.09 ft R=A/P=0.17ft S = 0.0079 ft/ft Otu 11 = 1. 000 cfs Peak 18 :00 17 :45 17 :15 14 :30 16 :00 10 :45 22 :45 6 :30 % Full= (0.333 cfs)/(1.000 cfs) = 0.33 or 33% full -----Flow Frequency Analysis------- -Peaks -Rank Return Prob (CFS) Period 0.436 1 100.00 0 .990 0.333 2 25.00 0 . 960 0.239 3 10.00 0 .900 0.197 4 5.00 0 .800 0. 187 5 3 .00 0 .667 0. 176 6 2 .00 0 . 500 0. 142 7 1 .30 0 .231 0. 123 8 1 .10 0 . 091 0. 402 50. 00 0 .980 As the above equation shows the worst case scenario pipe adequately conveys the 25 year storm under gravity. Therefore all pipes in the onsite conveyance system are adequately sized. BCRADESIGN.COM 42 Of/site A quantitative downstream analysis was not completed for the conveyance system affected by the project site based on two factors. First, the proposed developed condition for the project site contains a greater amount of pervious area than it does in the existing condition, thus reducing its generated runoff. Second, the proposed developed condition does include flow control while the existing condition does not, thus reducing the flow rates leaving the project site. Based on these two factors it was concluded that the project site would not have a negative effect of the downstream conveyance system and therefore no analysis would be necessary. Part of the proposed design is the relocation of a storm line owned and maintained by the City of Renton. Runoff from the site does not enter the conveyance system however; in relocating the line the pipe was also upsized from a 24" CMP to a 36" LCPE to prove the proposed pipe has adequate capacity. The backwater analysis used to size the pipe can be found below. Table 5-1: Offsite Pipe Relocation Areas Areas Area Area Zone %IMP Impervious Area Pervious Area (sf) (ac) (ac) (ac) 230,104 5.28 CA 100% 5.28 0.00 > Q) 31,818 0.73 R-14 85% 0.62 0.11 Cl Q) 1,912,429 43.90 R-8 75% 32.93 10.98 ~ c.. Total 38.83 11.09 KCRTS was used to determine the peak flows generated from the area tributary to the section of pipe. Based on the percent impervious guidelines given in Renton Surface Water Design Manual 3.2.2.1 impervious and pervious areas were calculated (see Table 5-1 above). To simplify the model pervious area was modeled as Till Grass and impervious area was modeled as Impervious. KCBW was then used to determine the hydraulic grade line in the pipe. BCRADESIGN.COM 43 Flow Frequency Analysis Time Series File·ttoff .tsf Project Location:Sea-Tac ---Annual Peak Flow Rates--------Flow Frequency Analysis------- Flow Rate Rank Time of Peak -Peaks Rank Return Prob (CFS) (CFS) Period 10.40 6 2/09/01 2 :00 20.68 1 100.00 0. 990 8.80 8 l/05/02 16 :00 14. 40 2 25.00 0. 960 12.45 3 12/08/02 18 :00 12.45 3 10.00 0. 900 9.88 7 8/26/04 2 :00 11. 80 4 5.00 0. 800 11. 80 4 10/28/04 16 :00 11. 08 5 3.00 0. 667 11. 08 5 l/18/06 16 :00 10. 40 6 2.00 0. 500 14.40 2 10/26/06 0 :00 9. 88 7 1. 30 0. 231 20.68 1 l/09/08 6 :00 8. 80 8 1.10 0. 091 Computed Peaks 18. 59 50.00 0.980 Fig_ure 5-2: Ofisite Pie_e Relocation Tai/water fj> HW/TW Data 1=1--·, Elevation@ 0.0: 1385.91 I 1l -- Stage(IIJ Dlscharge(cfs) 11.53 118.8 11.56 119.88 11.s8 1110.4 11.6 1111.00 11.62 1111.0 11.63 1112.45 11.68 1114.4 ' 11.78 1118.59 ' 11.82 1120.68 ' I ' 1-11-I ' I I Data Is sorted by Stage L _______ Edit PREVIOUS Screen Edit MEXT Screen Edit COMPLETE I This elevation sets where the Stage is 0.0 Note: TW values computed using the equation TW = (D+d,)/2 as supplied in the 2009 SWDM Section 4.2.2.1 BCRADESIGN.COM 44 Surcharge condition at intermediate junctions Tailwater from H\1/T\I File:TTOffTV.bwt Di~~ha~gc figngc· 2 to 22 ttep of 2. [cfs] Overflow Elevation: 398.61 fe~t Weir NONE Channel Width: 2. feet PIPE NO. 1 :l5 u: :l~ "(;f 0.47% OUTLET: 385.91 INLET: 386.08 INTYP: s JUNC NO. 11 OVERFLOV-EL: 398 j9 BEND: 45 DEG DIA/VIDTH: 4 .0 Q-RATIO: 0 .00 Q(CFS) Hll(FT) HV ELEV. * N-FAC DC DN TV DO DE H\10 HIII ******************************************************************************* 2 .00 1. 37 387. 45 * 0 .012 0 . 44 0 .42 1 .53 1 .53 1 .36 1 .37 0 .58 4 .00 1. 40 387. 48 * 0 .012 0 .63 0 .58 1 .53 1 .53 1 .36 1 .40 0 .84 6 .00 1 . 44 387. 52 * 0 .012 0 .77 0 . 71 1 .53 1 .53 1 .36 1 . 44 1 .04 8 .00 1 .SO 387. 58 * 0 .012 0 .90 0 .82 1 .53 1 .53 1 .36 1 .SO 1 .21 10 .00 1 .60 387. 68 * 0 .012 1 .01 0 . 92 1 .56 1 .56 1 .39 1 .60 1 .36 12 .00 1 . 71 387. 79 * 0 .012 1 .10 1 .01 1 .62 1 .62 1 . 44 1 .71 1 .50 14 .00 1 .83 387. 90 * 0 .012 1 .20 1 .09 1 .67 1 .67 1 .49 1 .83 1 .63 16 .00 1 .94 388. 02 * 0 .012 1 .28 1 .17 1 . 72 1 . 72 1 .53 1 .94 1 .76 18 .00 2 05 388. 13 * 0 .012 1 .36 1 .25 1 . 77 1 . 77 1 .57 2 .OS 1 .87 20 00 2 .16 388.24 * 0 . 012 1 . 44 1 .33 1 .81 1 .81 1 .61 2 .16 1 .99 **************** RANGE EXCEEDED IN H\1/TII FILE -DATA EXTRAPOLATED**************** 22.00 2.27 388.35 * 0 .012 1.51 1.40 1. 85 1. 85 1.64 2.27 2.10 PIPE NO. 2: 112 LF -36"CP @ 0.46% OUTLET: 386.08 INLET: 386. 60 INTYP: 2 Q(CFS) Hll(FT) HII ELEV. * N-FAC DC DN TII DO DE H\10 HIII ******************************************************************************* 2 . 00 0 . 86 387. 46 * 0 . 012 0 . 44 4 . 00 0 . 94 387. 54 * 0 .012 0 .63 6 .00 1 .OS 387. 65 * 0 .012 0. 77 8 .00 1. 19 387. 79 * 0 .012 0 .90 10 .00 1. 32 387. 92 * 0 .012 1 .01 12 .00 1 . 44 388 . 04 * 0 .012 1 .10 14. 00 1. 55 388.15 * 0 .012 1 .20 16 . 00 1 . 66 388.26 * 0 .012 1 .28 18 00 1. 76 388.36 * 0 .012 1 .36 20 .00 1. 86 388.46 * 0 .012 1 .44 22 .00 1. 97 388.57 * 0 .012 1 .51 Percent full for each pipe in the 22.00 cfs condition: Pipe No. 1: Pipe No. 2: y/D = (2.27 feet)/(3 feet)= 0.72 y/D = (1.97 feet)/(3 feet)= 0.66 0 .42 1 .37 1 .37 0 .85 0 .86 0 .56 0 .58 1 .40 1 .40 0 .88 0 .94 0 . 77 0 . 71 1 . 44 1 .44 0 . 92 1 .OS 0 . 92 0 .82 1 .50 1 .50 0 .97 1 .19 1 .OS 0 . 92 1 .60 1 .60 1 .06 1 .32 1. 17 1 .01 1 . 71 1 . 71 1 .17 1 . 44 1 .28 1 .10 1 .83 1 .83 1 .28 1 .55 1 .38 1 .18 1 . 94 1 .94 1 .40 1 .66 1 .48 1 .26 2 .05 2 .05 1 .52 1 .76 1 .58 1 .34 2 .16 2 .16 1. 64 1 .86 1 .67 1 . 41 2 .27 2 . 27 1 . 76 1 .97 1 . 77 As shown by the above table even subjected to 22.00 cfs (larger than the 100 year peak flow of 20.68) both pipes do not overtop the catch basins and provide well over 6 inches of freeboard. Also, as shown by the above calculations done in the same 22.00 condition both pipes are flowing under gravity. It is concluded, therefore, that this design for the offsite pipe upsize and replacement is sufficient. BCRADESIGN.COM 45 (; Ill () ::0 )> Section 6 -Special Reports and Studies BCRADESIGN.COM 46 GEOTECH CONSULTANTS, INC. Taco Time Northwest 3300 Maple Valley Highway Renton, Washington 98058 13256 Northeast 20th Street, Suite 16 Bellevue, Wcishington 98005 (425) 747-5618 FAX (425) 747-8561 November 11, 2013 JN 13419 Attention: Chris Tonkin via email: Chris@TacoTimeNWcom Subject: Transmittal Letter -Geotechnical Engineering Study Proposed Taco Time Restaurant and Second Retail Building 4114 Northeast 4th Street Renton, Washington Dear Mr. Tonkin: We are pleased to present this geotechnical engineering report for the proposed Taco Time Restaurant and a second retail building pad to be constructed in Renton. The scope of our services consisted of exploring site surface and subsurface conditions, and then developing this report to provide recommendations for general earthwork and design criteria for foundations, retaining walls, and pavements. This work was authorized by your acceptance of our proposal, P- 8694, dated July 29, 2013. The attached report contains a discussion of the study and our recommendations. Please contact us if there are any questions regarding this report, or for further assistance during the design and construction phases of this project. cc: BCRA -Mat Bergman via email: MBergman@bcradesign.com TRC/MRM: jyb Respectfully submitted, GEOTECH CONSULTANTS, INC. Thor Christensen, P.E. Senior Engineer GEOTECH CONSULTANTS. INC. GEOTECHNICAL ENGINEERING STUDY Proposed Taco Time Restaurant and Second Retail Building 4114 Northeast 4th Street Renton, Washington This report presents the findings and recommendations of our geotechnical engineering study for the site of the proposed restaurant and retail building to be located in Renton. We have been provided with an undated site plan that shows the planned location of a new Taco Time restaurant and a retail building. Based on this plan, we understand that the new restaurant will be located in the eastern portion of the site and a retail building will be located in the western portion of the site. Most of the remainder of the site will be covered with pavement. We anticipate that both structures will have a single story and that the floor elevations of the buildings will be close to the existing site grades. The existing Taco Time restaurant in the center of the property will be removed. If the scope of the project changes from what we have described above, we should be provided with revised plans in order to determine if modifications to the recommendations and conclusions of this report are warranted. SITE CONDITIONS SURFACE The Vicinity Map, Plate 1, illustrates the general location of the subject property. The site is bordered to the south by Northeast 4th Street, to the west by a gas station, to the east by an auto parts store, and to the north by a shopping center parking lot. A single-story restaurant is located in the central portion of the site. Portions of the building walls are constructed of brick. We did not observe cracking of the brick, and are not aware of settlement-related distress to the building. Most of the remainder of the site is covered with asphalt pavement, with some landscaping areas along portions of the site perimeter. The ground surface in the vicinity of the site is relatively flat. The ground surface on the west side of the site slopes gently down toward the south, and the ground surface on the east side of the site slopes gently down toward the southeast. There are no steep slopes on, or near, the property. However, a low-lying drainage is located southeast of the site, on the south side of Northeast 4th Street. SUBSURFACE The subsurface conditions were explored by drilling eight test borings at the approximate locations shown on the Site Exploration Plan, Plate 2. Our exploration program was based on the proposed construction, anticipated subsurface conditions and those encountered during exploration, and the scope of work outlined in our proposal. The borings were drilled on November 6, 2013 using a trailer-mounted, hollow-stem auger drill. Samples were taken at 2.5-and 5-foot intervals with a standard penetration sampler. This split- GEOTECH CONSULTANTS, INC. Taco Time Northwest November 11, 2013 JN 13419 Page 2 spoon sampler, which has a 2-inch outside diameter, is driven into the soil with a 140-pound hammer falling 30 inches. The number of blows required to advance the sampler a given distance is an indication of the soil density or consistency. A geotechnical engineer from our staff observed the drilling process, logged the test borings, and obtained representative samples of the soil encountered. The Test Boring Logs are attached as Plates 3 through 10. Soil Conditions Below the surficial asphalt, our test borings generally encountered fill material overlying native soil that consisted of silty sand with gravel to sand with gravel. The fill material was composed of silty sand with gravel, and the majority of the fill was medium dense, although some zones of the fill were loose and others were dense. The underlying native soil was dense to very dense within a few feet of the original ground surface. Some of the test borings encountered as much as a foot of loose buried topsoil material between the fill material and the underlying native soil. Although our explorations did not encounter cobbles or boulders, they are often found in soils that have been deposited by glaciers or fast-moving water. Groundwater Conditions Perched groundwater seepage was encountered at a depth of 0.5 feet in test boring B-1. No groundwater seepage was observed in the other test borings, which were left open for only a short time period. Therefore, the absence of seepage levels on the logs may not indicate the absence of static groundwater level. It should be noted that groundwater levels vary seasonally with rainfall and other factors. The stratification lines on the logs represent the approximate boundaries between soil types at the exploration locations. The actual transition between soil types may be gradual, and subsurface conditions can vary between exploration locations. The logs provide specific subsurface information only at the locations tested. If a transition in soil type occurred between samples in the borings, the depth of the transition was interpreted. The relative densities and moisture descriptions indicated on the test boring logs are interpretive descriptions based on the conditions observed during drilling. CONCLUSIONS AND RECOMMENDATIONS GENERAL THIS SECTION CONTAINS A SUMMARY OF OUR STUDY AND FINDINGS FOR THE PURPOSES OF A GENERAL OVERVIEW ONLY. MORE SPECIFIC RECOMMENDATIONS AND CONCLUSIONS ARE CONTAINED IN THE REMAINDER OF THIS REPORT. ANY PARTY REL YING ON THIS REPORT SHOULD READ THE ENTIRE DOCUMENT. The test borings conducted for this study encountered up to about 1 O feet of silty sand fill overlying native medium dense to very dense sand with gravel. We have not been provided with documentation of the existing fill material, which was likely placed as part of the original site development. Because the existing fill encountered in our test borings was generally medium dense, we anticipate that it will be feasible to support the structures on the existing fill material. However, supporting any structure on undocumented fill increases the risk of future structure GEOTECH CONSULTANTS, INC. Taco Time Northwest November 11, 2013 JN 13419 Page 3 settlement. The existing building is supported on the fill soil and appears to have performed acceptably. The risk of differential settlement of the foundations for the new buildings could be reduced by structurally stiffening the foundation system. A proof roll of the building subgrades should also be performed to identify areas of loose material, which would need to be over- excavated. The subgrade soils should be evaluated by an engineer from this firm before setting foundation forms. The erosion control measures needed during the site development will depend heavily on the weather conditions that are encountered. While site clearing will expose a large area of bare soil, the erosion potential on the site is relatively low due to the gentle slope of the ground. Existing pavements should be maintained wherever possible to reduce the area of bare soil. We anticipate that a silt fence may be needed around the downslope sides of any cleared areas. Rocked construction access roads should be extended into the site to reduce the amount of soil or mud carried off the property by trucks and equipment. Cut slopes and soil stockpiles should be covered with plastic during wet weather. Following rough grading, it may be necessary to mulch or hydroseed bare areas that will not be immediately covered with landscaping or an impervious surface. The drainage and/or waterproofing recommendations presented in this report are intended only to prevent active seepage from flowing through concrete walls or slabs. Even in the absence of active seepage into and beneath structures, water vapor can migrate through walls, slabs, and floors from the surrounding soil, and can even be transmitted from slabs and foundation walls due to the concrete curing process. Water vapor also results from occupant uses, such as cooking and bathing. Excessive water vapor trapped within structures can result in a variety of undesirable conditions, including, but not limited to, moisture problems with flooring systems, excessively moist air within occupied areas, and the growth of molds, fungi, and other biological organisms that may be harmful to the health of the occupants. The designer or architect must consider the potential vapor sources and likely occupant uses, and provide sufficient ventilation, either passive or mechanical, to prevent a build up of excessive water vapor within the planned structure. Geotech Consultants, Inc. should be allowed to review the final development plans to verify that the recommendations presented in this report are adequately addressed in the design. Such a plan review would be additional work beyond the current scope of work for this study, and it may include revisions to our recommendations to accommodate site, development, and geotechnical constraints that become more evident during the review process. We recommend including this report, in its entirety, in the project contract documents. This report should also be provided to any future property owners so they will be aware of our findings and recommendations. SEISMIC CONSIDERATIONS In accordance with the International Building Code (IBC), the site soil profile within 100 feet of the ground surface is best represented by Site Class Type C (Very Dense Soil and Soft Rock), As noted in the USGS website, the mapped spectral acceleration value for a 0.2 second (Ss) and 1.0 second period (S 1) equals 1.40g and 0.48g, respectively. The site soils are not susceptible to seismic liquefaction because of their dense nature. GEOTECH CONSULTANTS, INC. Taco Time Northwest November 11, 2013 CONVENTIONAL FOUNDATIONS JN 13419 Page 4 We recommend that the footings to support the new buildings all be continuous and have a minimum width of 16 inches. The foundations can bear on the existing fill material, or on structural fill where the ground surface will be elevated for the development. See the section entitled General Earthwork and Structural Fill for recommendations regarding the placement and compaction of structural fill beneath structures. In order to reduce differential settlement, the new foundations should be designed similar to grade beams, being able to theoretically span a distance of at least 10 feet without soil support. The foundations will typically consist of a footing containing three horizontal rebar with a reinforced stem wall sitting on the footing. Exterior footings should also be bottomed at least 18 inches below the lowest adjacent finished ground surface for protection against frost and erosion. Footing subgrades must be cleaned of loose or disturbed soil prior to pouring concrete. Depending upon site and equipment constraints, this may require removing the disturbed soil by hand. An allowable bearing pressure of 2,000 pounds per square foot (psi) is appropriate for footings supported on competent native soil. A one-third increase in this design bearing pressure may be used when considering short-term wind or seismic loads. For the above design criteria, it is anticipated that the total post-construction settlement of footings founded on competent native soil, or on structural fill up to 5 feet in thickness, will be about one-inch, with differential settlements on the order of one-inch in a distance of 30 feet along a continuous footing with a uniform load. Lateral loads due to wind or seismic forces may be resisted by friction between the foundation and the bearing soil, or by passive earth pressure acting on the vertical, embedded portions of the foundation. For the latter condition, the foundation must be either poured directly against relatively level, undisturbed soil or be surrounded by level, well-compacted fill. We recommend using the following ultimate values for the foundation's resistance to lateral loading: Coefficient of Friction 0.40 Passive Earth Pressure 350 pcf Where: (I) pcf Is pounds per cubic foot, and (Ii) passive earth pressure ls computed using the equivalent fluid density. If the ground in front of a foundation is loose or sloping, the passive earth pressure given above will not be appropriate. We recommend maintaining a safety factor of at least 1.5 for the foundation's resistance to lateral loading, when using the above ultimate values. SLABS-ON-GRADE The building floors can be constructed as slabs-on-grade atop the existing fill material, or on structural fill. The subgrade soil must be in a firm, non-yielding condition at the time of slab construction or underslab fill placement. Any soft areas encountered should be excavated and replaced with select, imported structural fill. Even where the exposed soils appear dry, water vapor will tend to naturally migrate upward through the soil to the new constructed space above it. This can affect moisture-sensitive flooring, cause imperfections or damage to the slab, or simply allow excessive water vapor into the space above GEOTECH CONSULTANTS, INC. Taco Time Northwest November 11, 2013 JN 13419 Page 5 the slab. All interior slabs-on-grade should be underlain by a capillary break or drainage layer consisting of a minimum 4-inch thickness of gravel or crushed rock that has a fines content (percent passing the No. 200 sieve) of less than 3 percent and a sand content (percent passing the No. 4 sieve) of no more than 10 percent. As noted by the American Concrete Institute (ACI) in the Guides for Concrete Floor and Slab Structures, proper moisture protection is desirable immediately below any on-grade slab that will be covered by tile, wood, carpet, impermeable floor coverings, or any moisture-sensitive equipment or products. ACI also notes that vapor retarders, such as 6-mil plastic sheeting, have been used in the past, but are now recommending a minimum 10-mil thickness. A vapor retarder is defined as a material with a permeance of less than 0.3 perms, as determined by ASTM E 96. It is possible that concrete admixtures may meet this specification, although the manufacturers of the admixtures should be consulted. Where vapor retarders are used under slabs, their edges should overlap by at least 6 inches and be sealed with adhesive tape. The sheeting should extend to the foundation walls for maximum vapor protection. If no potential for vapor passage through the slab is desired, a vapor barrier should be used. A vapor barrier, as defined by ACI, is a product with a water transmission rate of 0.01 perms when tested in accordance with ASTM E 96. Reinforced membranes having sealed overlaps can meet this requirement. DRAINAGE CONSIDERATIONS Foundation drains should be used where (1) crawl spaces or basements will be below a structure, (2) a slab is below the outside grade, or (3) the outside grade does not slope downward from a building. Drains should also be placed at the base of all earth-retaining walls. These drains should be surrounded by at least 6 inches of 1-inch-minus, washed rock and then wrapped in non-woven, geotextile filter fabric (Mirafi 140N, Supac 4NP, or similar material). At its highest point, a perforated pipe invert should be at least 6 inches below the bottom of a slab floor or the level of a crawl space, and it should be sloped for drainage. All roof and surface water drains must be kept separate from the foundation drain system. A typical drain detail is attached to this report as Plate 11. For the best long-term performance, perforated PVC pipe is recommended for all subsurface drains. Water should not be allowed to stand in any area where foundations, slabs, or pavements are to be constructed. Final site grading in areas adjacent to buildings should slope away at least 2 percent, except where the area is paved. Surface drains should be provided where necessary to prevent ponding of water behind foundation or retaining walls. PAVEMENT AREAS The pavement section may be supported on the existing fill. Because the site soils are silty and moisture sensitive, we recommend that the pavement subgrade must be in a stable, non-yielding condition at the time of paving. Granular structural fill or geotextile fabric may be needed to stabilize soft, wet, or unstable areas. To evaluate pavement subgrade strength, we recommend that a proof roll be completed with a loaded dump truck immediately before paving. In most instances where unstable subgrade conditions are encountered, an additional 12 inches of granular structural fill will stabilize the subgrade, except for very soft areas where additional fill could be required. The subgrade should be evaluated by Geotech Consultants, Inc., after the site is stripped and cut to grade. Recommendations for the compaction of structural fill beneath pavements are GEOTECH CONSULTANTS, INC. Taco Time Northwest November 11, 2013 JN 13419 Page 6 given in the section entitled General Earthwork and Structural Fill. The performance of site pavements is directly related to the strength and stability of the underlying subgrade. The pavement for lightly loaded traffic and parking areas should consist of 2 inches of asphalt concrete (AC) over 4 inches of crushed rock base (CRB) or 3 inches of asphalt-treated base (ATB). We recommend providing heavily loaded areas with 3 inches of AC over 6 inches of CRB or 4 inches of ATB. Heavily loaded areas are typically main driveways, dumpster sites, or areas with truck traffic. Increased maintenance and more frequent repairs should be expected if thinner pavement sections are used. The pavement section recommendations and guidelines presented in this report are based on our experience in the area and on what has been successful in similar situations. As with any pavements, some maintenance and repair of limited areas can be expected as the pavement ages. Cracks in the pavement should be sealed as soon as possible after they become evident, in order to reduce the potential for degradation of the subgrade from infiltration of surface water. For the same reason, it is also prudent to seal the surface of the pavement after it has been in use for several years. To provide for a design without the need for any maintenance or repair would be uneconomical. GENERAL EARTHWORK AND STRUCTURAL FILL All building and pavement areas should be stripped of surface vegetation, topsoil, organic soil, and other deleterious material. It is important that existing foundations be removed before site development. Existing utilities to be abandoned within structural areas must be removed, and the trenches backfilled with structural fill. The stripped or removed materials should not be mixed with any materials to be used as structural fill, but they could be used in non-structural areas, such as landscape beds. Structural fill is defined as any fill, including utility backfill, placed under, or close to, a building, behind permanent retaining or foundation walls, or in other areas where the underlying soil needs to support loads. All structural fill should be placed in horizontal lifts with a moisture content at, or near, the optimum moisture content. The optimum moisture content is that moisture content that results in the greatest compacted dry density. The moisture content of fill is very important and must be closely controlled during the filling and compaction process. The allowable thickness of the fill lift will depend on the material type selected, the compaction equipment used, and the number of passes made to compact the lift. The loose lift thickness should not exceed 12 inches. We recommend testing the fill as it is placed. If the fill is not sufficiently compacted, it can be recompacted before another lift is placed. This eliminates the need to remove the fill to achieve the required compaction. The following table presents recommended relative compactions for structural fill: GEOTECH CONSULTANTS, INC. Taco Time Northwest November 11, 2013 Use of On-Site Soil LOCATION OF FILL PLACEME'.'l'f Beneath footings, slabs 95% or walkwavs Filled slopes and behind 90% retaininQ walls 95% for upper 12 inches of Beneath pavements subgrade; 90% below that level Where: Minimum Relative Compaction is the ratio, expressed In percentages, of the compacted dry density to the maximum dry density) as determined in accordance with ASTM Test Designation D 1557-91 (Modified Proctor). JN 13419 Page 7 If grading activities take place during wet weather, or when the silty, on-site soil is wet, site preparation costs may be higher because of delays due to rain and the potential need to import granular fill. The on-site soil is generally silty and therefore moisture sensitive. Grading operations will be difficult during wet weather, or when the moisture content of this soil exceeds the optimum moisture content. Moisture-sensitive soil may also be susceptible to excessive softening and "pumping" from construction equipment, or even foot traffic, when the moisture content is greater than the optimum moisture content. It may be beneficial to protect subgrades with a layer of imported sand or crushed rock to limit disturbance from traffic. Structural fill that will be placed in wet weather should consist of a coarse, granular soil with a silt or clay content of no more than 5 percent. The percentage of particles passing the No. 200 sieve should be measured from that portion of soil passing the three-quarter-inch sieve. LIMITATIONS The conclusions and recommendations contained in this report are based on site conditions as they existed at the time of our exploration and assume that the soil and groundwater conditions encountered in the test borings are representative of subsurface conditions on the site. If the subsurface conditions encountered during construction are significantly different from those observed in our explorations, we should be advised at once so that we can review these conditions and reconsider our recommendations where necessary. Unanticipated conditions are commonly encountered on construction sites and cannot be fully anticipated by merely taking samples in test borings. Subsurface conditions can also vary between exploration locations. Such unexpected conditions frequently require making additional expenditures to attain a properly constructed project. It is recommended that the owner consider providing a contingency fund to accommodate such potential extra costs and risks. This is a standard recommendation for all projects. This report has been prepared for the exclusive use of Taco Time Northwest and its representatives for specific application to this project and site. Our conclusions and recommendations are professional opinions derived in accordance with current standards of GEOTECH CONSULTANTS, INC. Taco Time Northwest November 11, 2013 JN 13419 Page 8 practice within the scope of our services and within budget and time constraints. No warranty is expressed or implied. The scope of our services does not include services related to construction safety precautions, and our recommendations are not intended to direct the contractor's methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. Our services also do not include assessing or minimizing the potential for biological hazards, such as mold, bacteria, mildew and fungi in either the existing or proposed site development. ADDITIONAL SERVICES In addition to reviewing the final plans, Geotech Consultants, Inc. should be retained to provide geotechnical consultation, testing, and observation services during construction. This is to confirm that subsurface conditions are consistent with those indicated by our exploration, to evaluate whether earthwork and foundation construction activities comply with the general intent of the recommendations presented in this report, and to provide suggestions for design changes in the event subsurface conditions differ from those anticipated prior to the start of construction. However, our work would not include the supervision or direction of the actual work of the contractor and its employees or agents. Also, job and site safety, and dimensional measurements, will be the responsibility of the contractor. During the construction phase, we will provide geotechnical observation and testing services when requested by you or your representatives. Please be aware that we can only document site work we actually observe. It is still the responsibility of your contractor or on-site construction team to verify that our recommendations are being followed, whether we are present at the site or not. The scope of our work did not include an environmental assessment, but we can provide this service, if requested. The following plates are attached to complete this report: Plate 1 Plate 2 Plates 3 -10 Plate 11 Vicinity Map Site Exploration Plan Test Boring Logs Typical Footing Drain Detail GEOTECH CONSULTANTS, INC. Taco Time Northwest November 11, 2013 JN 13419 Page 9 We appreciate the opportunity to be of service on this project. If you have any questions, or if we may be of further service, please do not hesitate to contact us. TRC/MRM: jyb Respectfully submitted, GEOTECH CONSULT ANTS, INC. Thor Christensen, P.E. Senior Engineer GEOTECH CONSULTANTS, INC. . ' --if 1 ...... l!!!!-"'!!7~------ GEOTECH CONSULTANTS, INC. (Source: Microsoft Streets and Trips, 2004) VICINITY MAP 4114 Northeast 4th Street Renton, Washington 'Job No: 13419 I Date. I Nov. 2013 Legend: " Test boring location GEOTECH CONSULTAi'ITS, INC. SITE EXPLORATIOJ\ PLAN 4114 Northeast 4th Street Renton, Washington Job No: Dale: Plate: 13419 Nov. 2013 No Scale NORTH 2 BORING 1 Description f----l2.5 inches of asphalt "---·--·-·- - -30 Gray-brown silty SAND with gravel, fine to coarse-grained, moist, dense (FILL) -FILL 5- I-9 -becomes loose l==nl-------------------will - SM' 5016" 31 ID]J Brown silty SAND with gravel, fine to coarse-grained, moist, very dense 10- • Test boring was terminated on November 6, 2013 at 11.0 feet. • Slight groundwater seepage was observed at 0.5 feet during drilling. I- I- 151-- .... I- .... 201-- ' TEST BORING LOG -it GEOTECH 4114 Northeast 4th Street CONSULTANTS, INC. Renton, Washington 1 t Job I Date: I Logged by: I Plate: <-7 13419 Nov. 2013 TRC 3 - - ... 5'-- I- ... ... ... ... 1-. 15--... ... - - 20-- ' ~ 1 \; BORING 2 Description ~~1\2 inches of asphalt Gray silty SAND with gravel and trace organics, fine to coarse-grained, moist, loose (FILL) 25 2 I FILL -becomes medium-dense 9 -becomes loose -·--.. -~=-==c::_cc__:c::,::....,,~~~--~-- Dark brown silty SAND with gravel and organics, fine to coarse-grained, moist, loose {TOPSOIL) ko-,., -.., ~,0d------------------------ 9,o 0 o 52 41,S; Tan SAND with gravel, fine to coarse-grained, moist, very dense i ,,0o ,:; * Test boring was terminated on November 6, 2013 at 14.0 feet. * No groundwater was encountered during drilling . TEST BORING LOG GEOTECH 4114 Northeast 4th Street CONSULTANTS, INC. Renton, Washington Job I Date: I Logged by: I Plate: ? 13419 Nov. 2013 TRC 4 5 10 20 BORING 3 Description 2.5 inches of asphalt_.._ __ 33 1 I Gray-brown silty SAND with gravel, fine to coarse-grained, moist, dense (FILL) 1 O 2 I FILL -becomes medium dense Dark brown silty SAND with gravel and organics, fine to coarse-grained, ,___ _ _, moist, loose (TOPSOIL) 50/1" 6 I Gray silty SAND with gravel, fine to coarse-grained, moist, very dense * Test boring was terminated on November 6, 2013 at 15.5 feet. * No groundwater was encountered during drilling. GEOTECH CONSULTANTS, INC. TEST BORING LOG 4114 Northeast 4th Street Renton, Washington Job Date: Logged by: Plate: 13419 Nov. 2013 TRC 5 I- - - I- 51-- .... I- .... I- 10--... .... .... .... .... .... .... - 20- BORING 4 Description 44 FILL Gray silty SAND with gravel, fine to coarse-grained, moist, dense (FILL) 14 --------------~ Dark brown silty SAND with gravel and organics, fine to coarse-grained, moist, loose (TOPSOIL) h-,~d---------------------------- •I: ii• ,, .. 4 1 SM 50/6" Gray-brown silty SAND with gravel, fine to coarse-grained, moist, very dense 61 FJ\:: .. ,,1-------s ---------------- 51 ~~; Gray SAND with gravel, fine to coarse-grained, wet, very dense If\ .,o,, t) * Test boring was terminated on November 6, 2013 at 14.0 feet. * No groundwater was encountered during drilling . ---. _:i ·" G EOTECH ~ CONSULTANTS, INC. TEST BORING LOG 4114 Northeast 4th Street Renton, Washington ,~~l='!"""l,,_~-!!!'!!!!! ................... _. Job I Date: -r Logged by: I Plate: 13419 Nov. 2013 I TRC 6 ... .... .. - 5 I-- ... ... .... 10--... ... ... 15- -- I- 20'-- ' ~t, 1 i ~ BORING 5 Description •:;:,-tj" 1~i_nches of asphalt ___ _ 24 ,;, t . .,°o O oo <:., ,()o<:.,go e '> <:, 0 a ooe;a · , ~ oa<) ,!) "%• 0 '" 1 I (~ ~:!1 Gray-brown SAND with gravel, fine to coarse-grained, moist, medium-dense "o'°,/'0 0'!:. c<".:,"' ~<>o'-'f? 30 50/6" o o ~ ~ a, tj's~·f; 2 It:.: .t~"..~i -becomes dense and brown e, e,Pe,0 l,~ i,°':a~"' t, o o <> Oo:> ,:-,,.i Q g<> lo' o 0o• ' I"'~ .. oo<'J ,:,<1 1:," f.,,Pat~ <::, 0 0 1::,go <:>" r;,"'o' 0 a, ~· .;'fa~"' o 0'° Oo 0<> 3 I f,;·,i~" -becomes very dense and gray, increased silt content • Test boring was terminated on November 6, 2013 at 10.5 feet. * No groundwater was encountered during drilling . TEST BORING LOG GEOTECH 4114 Northeast 4th Street CONSULTANTS, INC. Renton, Washington Job I Date: I Logged by: I Plate: )'-13419 Nov. 2013 TRC 7 - - -49 i- 5 '-- i-29 i- - 10- 50/6" .... i- .... - 151- .... I- .... .... 20-- 1 I FILL BORING 6 Description , 2 inches of asphalt '---=--"-""--'-'--=-....c'--="-'-'--'=----------------------------- Gray silty SAND with gravel, fine to coarse-grained, moist, dense (FILL} -becomes medium-dense Dark brown silty SAND with gravel and orgarilcs, tine to coarse-grained, moist, loose (TOPSOIL} Brown SAND with gravel, fine to coarse-grained, moist, medium-dense -becomes very dense * Test boring was terminated on November 6, 2013 at 11.0 feet. * No groundwater was encountered during drilling . ~t, ~!~T~lf,s5!f. ~~·~- TEST BORING LOG 4114 Northeast 4th Street Renton, Washington -v 7 Job I Date: !Logged by: IP/ate: 13419 Nov. 2013 TRC 8 .... ... .... 5 ..... .... I- .... I- .... .... .... - -- .... 20-- ' ~t, , • y BORING 7 Description ---~c:hes of asphalt FILL --·------------- 19 38 19 49 Gray silty SAND with gravel, fine to coarse-grained, moist, medium-dense IFILLL_ . Dark brown silty SAND with gravel and organics, fine to coarse-grained, moist, loose (TOPSOIL) Brown SAND with gravel, fine to coarse-grained, moist, medium-dense -becomes dense -becomes medium-dense and gray -becomes dense * Test boring was terminated on November 6, 2013 at 16.Sfeet. * No groundwater was encountered during drilling. TEST BORING LOG GEOTECH 4114 Northeast 4th Street CONSULTANTS, INC. Renton, Washington Job I Date: I Logged by: I Plate: -13419 Nov. 2013 TRC 9 I,,. - - 5-- .... I,,. I,,. .... 10-- .... I- .... .... 15- .... I,,. .... 20- ' ~i1 ~ j ; 23 FILL 10 ~~.."' }J'" BORING 8 Description 1.5 inches of asphalt ------··--·------------------- Gray silty SAND with gravel, fine to coarse-grained, moist, medium-dense (FILL) >o { 'o 0 tho "' ,c.,,.,g,;, "'"' "'"' " 47 3 ,~~sfi;{ Gray-brown SAND with gravel, fine to coarse-grained, moist, very dense Js~f~ 50/0" 4 ~ 0" (J " !;fob.0 oO"'<>oOe::, (;, ,,Q 'l,"00 o o"',/'oO-; (:,"' "' .. 1.oeo "' • <> 0 "' o <> 0 " t .;'lf'ob,o * Test boring was terminated on November 6, 2013 at 15.0 feet. * No groundwater was encountered during drilling. TEST BORING LOG GEOTECH 4114 Northeast 4th Street CONSULTANTS, INC. Renton, Washington Job I Date: -, Logged by: I Plate: ? 13419 Nov. 2013 TRC 10 Slope backfill away from foundation. Provide surface drains where necessary. Backfill (See text for requirements) Tightline Roof Drain (Do not connect to footing drain) Washed Rock (7/8" min. size) Nonwoven Geotextile Filter Fabric NOTES: '---4" Perforated Hard PVC Pipe (Invert at least 6 inches below slab or crawl space. Slope to drain to appropriate outfall. Place holes downward.) Vapor Retarder/Barrier and Capillary Break/Drainage Layer (Refer to Report text) (1) In crawl spaces, provide an outlet drain to prevent buildup of water that bypasses the perimeter footing drains. (2) Refer to report text for additional drainage, waterproofing, and slab considerations. GEOTECH CONSULTANTS, INC. FOOTING DRAIN DETAIL 4114 Northeast 4th Street Renton, Washington 'Job No: 13419 I Date: I Nov.2013 I Plate: Section 7 -Other Permits This section is to be completed and provided with the final submission of this report. BCRADESIGN.COM 68 rii tD n ;,ti > Section 8 -CSWPPP Analysis and Design This section is to be completed and provided with the final submission of this report. BCRADESIGN.COM 69 Section 9 -Bond Quantities, Facility Summaries, and Declaration of Covenant This section is to be completed and provided with the final submission of this report. BCRADESIGN.COM 70 Section 10 -Operations and Maintenance Manual This section is to be completed and provided with the final submission of this report. BCRADESIGN.COM 71 l!il ttl (") ::c >