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HomeMy WebLinkAboutMISCTECHNICAL INFORMATION REPORT Proposed Harper Engineering Parking Lot Addition 800 S.K 7th Street Renton, Washington 98057 4'O H A tj. o_ 44" k� fir' E.'V Gti74 Prepared for: Harper Engineering Co. 700 S.W. 7th Street Renton, Washington 98057 August 22, 2014 Our Job No. 16585 CIVIL LNGINFFRING, LAND PLANNING, SURVEYING 18215 72ND AVENUE SOUTH KENT, 1NA 58032 (425) 251-6222 (425)25- ' -8782 FAX BRANCH OFFICES ♦ TUMVVATER, WA ♦ LONG BEACH, CA ♦ ROSEVILLE, CA tSAN DIEGO, CA www.barghauSen .corn TABLE OF CONTENTS 1.0 PROJECT OVERVIEW Figure 1 — Technical information Report (TIR) Worksheet Figure 2 — Site Location Figure 3 — Drainage Basin, Subbasins, and Site Characteristics Figure 4 - Sails 2.0 CONDITIONS AND REQUIREMENTS SUMMARY 2.1 Analysis of the Core Requirements 2.2 Analysis of the Special Requirements 3.0 OFF-SITE ANALYSIS 4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN 6.0 SPECIAL REPORTS AND STUDIES 7.0 OTHER PERMITS &0 CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN ANALYSIS AND DESIGN 9.0 BOND QUANTITIES, FACILITIES SUMMARIES, AND DECLARATION OF COVENANT 10.0 OPERATIONS AND MAINTENANCE MANUAL 16585.003.doc 1.0 PROJECT OVERVIEW 1.0 PROJECT OVERVIEW The proposed project site is located on a 1.026 -acre parcel just north of the existing Harper Engineering development. This parcel is also owned by Harper Engineering and will have 24,000 square feet of permeable asphalt installed in the upper reaches of this development area. The site is located within the Southwest quarter of Section 18, Township 23 North, Range 5 East, Willamette Meridian, City of Renton, King County, Washington. More particularly the site is located in a #andlocked area at 800 S W. 7th Street within the City of Renton. Railroad tracks form the project site's northern, southern, and eastern boundaries with other commercial property bordering on the west. The existing condition of the site consists of vacant raw land with second growth forest over portions of it and thick brush over the remaining portion of the site. There is an existing wetland located in the northwest corner of the overall area. Two railroad grades form the project's north, east, and south boundaries as mentioned previously and these road grades are higher in elevation than the site is. The proposal for this development is to provide an asphalt roadway crossing of the Burlington Northern Railroad track along the southern property line of the site with access coming from the existing Harper Engineering development on the other side of the railroad tracks. Then permeable asphalt will be constructed totaling 24,000 square feet with a 1 percent slope from south to north and a long-term infiltration rate of 0.3 inches per hour as determined by the r geotechnical engineer for this project. Please refer to Section 6.0 of the Technical Information Report for the soils report prepared for this project. The proposed new parking lot will have appropriate drive aisles with intermittent landscaping islands, all to create a site conforming to the requirements of the City of Auburn. In addition, the site is located on the western fringe of an aquifer recharge area; however, the on-site soils exhibit an infiltration rate slow enough to provide treatment for stormwater runoff infiltrating through them in order that a liner will not be required for these soils. This project will include the clearing of vegetated land with retention of as many large -diameter trees as physically possible with a development of this nature. There will be no impacts to the downstream drainage course from this site which outfalls, should the infiltration facilities ever overtop, to the Black River area within several hundred feet west of the project site. There are two soil types on this project site, Woodinville silt loam and Beausite gravelly sandy loam with 6 to 15 percent slopes also on the project site. Please refer to the Soils Map on the following pages of this report for how the on-site soils were configured on the project site. The King County Runoff Time Series (KCRTS) hydrology model was utilized in sizing the permeable asphalt pavement section for this project site. A 10 -inch section was elected with 3 inches of permeable asphalt over 3 inches of gravel base with a minimum of fines over another 4 inches of gravel material. 165B5,003.doc Figure 1 -Technical Information Report (TIR) kING COtJNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER Project Owner Harper Engineering Phone Address 700 S.W. 7th Street, Renton. WA Project Engineer Costa Philippides Company Bar h� ausen Consulting Engineers, Inc. Phone (425) 251-6222 Part 3 TYPE OF PERMIT APPLICATION ❑ Landuse Services Subdivision I Short Subd. I UPD ® Building Services MIF I Commercial I SFR ® Clearing and Grading ❑ Right -of -Way Use ❑ Other Part 5 PLAN AND REPORT INFORMATION Technical Information Report Type of Drainage Review Ful / Targeted (circle): Large Site Date (include revision dates): Date of Final: Part 6 ADJUSTMENT APPROVALS Part 2 PROJECT LOCATION AND DESCRIPTION Project Name Harper Eng. Parkin Lot Ex . DDES Permit* Location Township 23 North Range 5 East Section 18 Site Address 800 S.W. 7th Street Renton WA Part 4 OTHER REVIEWS AND PERMITS ❑ DFW HPA ❑ Shoreline ❑ COE 404 Management ❑ DQE Dam Safety 1:1 Structural Rockery/Vault/ ❑ FEMA Floodplain ESA Section 7 ❑ COE Wetlands ❑ Other j Site improvement Plan (Engr. Plans) I Type (circle one): Ful] f Modified 1 Small Site Date (include revision dates): Date of Final: Type (circle one): Standard / Complex f Preapplication I Experimental I Blanket Description: (include conditions in TIR Section 2) Date of 2009 Surface Water Design Manual I/t/09 I 16585.004.doc KING COUNTY, WAS1IINGITON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 7 MONITORING REQUIREMENTS Monitoring Required: Yes 1 No Start Date: Completion Date: Part 8 SITE COMMUNITY AND DRAINAGE BASIN Community Plan: Renton Special District Overlays: Drainage Basin: Stormwater Requirements: Describe: Part 9 ONSITE* AND ADJACENT SENSITIVE AREAS ❑ River/Stream -- - ❑ Steep Slope ❑ Lake ❑ Erosion Hazard ® Wetlands ❑ Landslide Hazard ❑ Closed Depression ❑ Coal Mine Hazard ® Floodplain To the west on adjacent pfo.perty ❑ Seismic Hazard ❑ Other ❑ Habitat Protection Part 10 SOILS Soil Type Woodinville silt loam Beausite gravelly sandv loam Slopes 6 to 15 Rercent ❑ High Groundwater Table (within 5 feet) ❑ Sole Source Aquifer ❑ Other ❑ Seeps/Springs ❑ Additionaf Sheets Attached 2009 Surface Water Design Manual 2 Erosion Potential 1/1/09 I6585.004.doc KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAI, TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 11 DRAINAGE DESIGN LIMITATIONS REFERENCE LIMITATION 1 SITE CONSTRAINT ❑ Core 2 — Offsite Analysis ❑ Sensitive/Critical Areas ❑ SEPA ❑ Other El ❑ Additional Sheets Attached Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Area) Threshold Discharge Area: (name or description) Core Requirements (all 8 apply) Discharge at Natural Location Number of Natural Dischar a Locations: I Offsite Analysis Level: 1 / 2 1 3 dated: NIA Flow Control Level: 1 1 2 1 3 or Exemption Number (incl, fac€lity summary sheet) Small Site BMPs Porous pavement Conveyance System Spill containment located at: NIA Erosion and Sediment Control ESC Site Supervisor: Contact Phone: After Hours Phone: Maintenance and Operation Responsibility: Private / Public If Private, Maintenance Log Required: es / No Financial Guarantees and _ Provided: Yes 1 No Liability WAtPr Oimhty Tvna' Racir / ganc I nko ! Fr% hamar P�eirm I Pnn (include facility summary sheet) or Exemption No. Landscape Mana Plan: Yes / No Special Requirements (as applicable) Area Specific Drainage Type: CDA / SDO / MDP / BP / LMP f Shared Fac. / None Requirements Name: Floodplain/Floodway Delineation Type: Major / Minor / Exemption / None 100 -year Base Blood Elevation (or range): Datum: Flood Protection Facilities Describe: Source Control Describe landuse: (comm./industrial landuse) Describe any structural controls: 2004 Surface Water Design Manual V1/09 3 16585.004,doc M& KING COUNTY, WASIIINGTON, SURFACE WATER DESIGN MANUAL TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Oil Control High -use Site: Yes ! INol Treatment BM P: Maintenance Agreement: Yes 1 N� with whom? Other Drainage Structures Qescn e: Part 13 EROSION AND SEDIMENT CONTROL REQUIREMENTS FACILITY DESCRIPTIONS Note: Include Facility Su mary and Sketch MINIMUM ESC REQUIREMENTS Type/Description MINIMUM ESC REQUIREMENTS T elDescri tion DURING CONSTRUCTION AFTER CONSTRUCTION ® Clearing Limits ® Stabilize Exposed Surfaces ❑ Cover Measures ® Remove and Restore Temporary ESC Facilities ® Perimeter Protection ® Clean and Remove All Silt and Debris Ensure ❑ Traffic Area Stabilization Operation of Permanent Facilities ❑ Sediment Retention ❑ Flag Limits of SAO and open space preservation areas ❑ Surface Water Control � ❑ Other ❑ Dewatering Control ❑ Dust Control ❑ Flow Control Part 14 STORMWATER FACILITY DESCRIPTIONS Note: Include Facility Su mary and Sketch Flow Control Type/Description Water Quality T elDescri tion ❑ Detention ❑ Infiltration ❑ Regional Facility ❑ Shared Facility Flow Control BMPs ❑ Other ❑ Biofiltration ❑ Wetpool ❑ Media Filtration ❑ Oil Control ❑ Spill Control ® Flow Control BMPs porous Asphalt ❑ Other i - 1 porous Asphalt 2009 Surface Water Design Manual 1/1/09 4 16585.004.doc KING CM,NTY, WASHINGTON, SURFACE WATER DESIGN MANUAI, TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 15 EASEMENTS/TRACTS ❑ Drainage Easement ❑ Covenant ❑ Native Growth Protection Covenant ❑ Tract ❑ Other Part 16 STRUCTURAL ANALYSIS ❑ Cast in Place Vault ❑ Retaining Wall ❑ Rockery > 4' High ❑ Structural on Steep Slope ❑ 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 h re is accurate. IA _ - - _ Signed/Date 2009 Surface Water Design Manual 111,1/09 5 16585.004.dac. Figure 2 -- Site Location �5 s � nth f'i .r m w '1 5tl Sunset Bird 9000f Sy, . N � F m Jho Horiaonlal: N. T.S. I' $liyt�;Ttofj ` St p\ S ,t+��tr 5!l e 18215 72ND AVENUF SOUTH KENT, WA 88032 7ipj (425) 251-8222 ahPrn (425) 251-8782 o .. sG�T '♦r CIVIL ENGINEERING, LAND PLANNING, �p�' �M� Efr64{i� SURVEYING, ENVIRONMENTAL SERVICES SITE � a sv'r 7:h St Sw 701 5t 5:v i 111 Sl Ll } V) a) 7 Si � m <eb C O 9 30th SZ sw cw LL �Aht 1dCh 5L �tiV [yC��l� WY �j�IJ 1Zt�� �+ RUERENGE nand McNally (2014) Scale, Horiaonlal: N. T.S. 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Q Z D !�40 0 wC 0 N LL J W _j m Q Wild E)Nb VJJ!DNIC]#U0Afa,adi'dd amcd1v m5 °�aaa� 2WdV 3 "'a NO1SlJ1321 'ON �I 3S'a MR A ���/} /1'�gj�j [/'�� I ,�Vi ��w Idag SMACAk �ygnd/6k �p!r1g/6uluuol� ��{(, ly, C. 'JIMMY:! NO.LD SIHS V M aN Vil ■E•1.Y f 11 11V Q .O - I '/•�{ H vy�= �wqy �;yy ye�7�I +�.gy�ygiy..��H'{w�e1 �0 ��,i D y NYWa� Y ON18../3NION-3 U3,JH Y 1 E �K C Ieel/regia av4 �rulozleon E 3:'y:. CtlPG. wnN l�'42LK ;°"r75 01431Mi-5 ,- T • I �� -[U L26* ` 'nN Rof- 'V1S ;_OYdS a3dYa IffW 6 iole a3Lbd X-3.; ;( :3PIVFI�1lJ Z [W� U1 J Z V m _ _¢ p N WZ 4M W m IX in ��3NnQ in S4tY r-. r+ 47��vvU Q Z D !�40 0 wC 0 N LL J W _j m Q Wild E)Nb VJJ!DNIC]#U0Afa,adi'dd amcd1v m5 °�aaa� 2WdV 3 "'a NO1SlJ1321 'ON �I 3S'a MR A ���/} /1'�gj�j [/'�� I ,�Vi ��w Idag SMACAk �ygnd/6k �p!r1g/6uluuol� ��{(, ly, C. 'JIMMY:! NO.LD SIHS V M aN Vil ■E•1.Y f 11 11V Q .O - I '/•�{ H vy�= �wqy �;yy ye�7�I +�.gy�ygiy..��H'{w�e1 �0 ��,i D y NYWa� Y ON18../3NION-3 U3,JH Y 1 E �K C Ieel/regia av4 �rulozleon E 3:'y:. CtlPG. wnN l�'42LK ;°"r75 01431Mi-5 ,- T • I �� -[U L26* ` 'nN Rof- 'V1S ;_OYdS a3dYa IffW 6 iole a3Lbd X-3.; ;( :3PIVFI�1lJ Im ON =*&men m p C 1 i Figure 4 -Soils 1 r. 1 REFERENCE: USDA, Natural Resources Conservation Service Scale: Horizontal: N.%S. Verixel. NIA q,P�A g, 18215 72NDAVENJE SOUTH ri KENT, VVA 98032 co 2 (425) 251-6222 n (425)251-8782 O z x �rnc� CIVIL ENGINEERING, LANG PLANNING, EM�i�b4 SURVEYING, ENVIRONMENTAL SERVICES A:II600Cs1965851exhibirlgraphlcs176585 serlxdr LEGEND: Wo = Woodinville silt loam BeC = Beausite gravelly sandy loam, 6-15% slopes For, Tifle. HARPER ENGINEERING RENTON, WASHINGTON SOIL SURVEY MAP Job Number INNI-M 08120/14 2.0 CONDITIONS AND REQUIREMENTS SUMMARY 2.0 CONDITIONS AND REQUIREMENTS SUMMARY 2.1 Analysis of the Eight Core Requirements Core Requirement No, 1: Discharge at the Natural Location, Response: All surface water runoff from this new development will be infiltrated into the soil below the permeable asphalt with the remainder of the site functioning as it does under existing conditions. Therefore, this requirement is met, Core Requirement No. 2: Off -Site Analysis. Response: Since infiltration of stormwater runoff is the proposed means of Flow Control BMP for this project site with all of the runoff infiltrating readily into ground, no Off -Site Analysis was prepared for this site. However, should runoff ever overtop the porous pavement, it would sheet flow to the west into the Black River drainage basin at the Black River Park. Core Requirement No, 3: Flow Control. Response: Flow control is being provided with this project in the form of a Flow Control BMP for the entire developed area on the site which meets the requirements of the City of Renton for projects of this nature. Therefore, this Core Requirement is met. Core Requirement No. 4,- Conveyance System. Response: There is no conveyance system proposed for this development; therefore, this Core Requirement does not apply. Core Requirement No. 5: Erosion and Sediment Control, Response: All erosion and sediment control requirements of the 2009 King County Surface Water Design Manual will be followed with this site as modified by the City of Renton's amendments. Cover measures will be provided, clearing limits will be specified, a rock construction entrance will be installed, and downstream perimeter protection will also be utilized in the form of silt fences to maintain that all runoff leaving the project site either infiltrates, or should it concentrate be dispersed through the native vegetation with no sediment entrained in the water. Core Requirement No. S: Maintenance and Operations. Response: A Maintenance and Operations Plan will be prepared with the final preparation of the Technical Information Report for this project. Core Requirement No. 7: Financial Guarantees and Liability. Response: All financial guarantees and liabilities requirements of the City of Renton will be followed for this project as per the requirement of the City. Core Requirement No. 8: Water Quality, Response: The on-site soils exhibit water quality treatment capability since the infiltration rate is so small. Therefore, no further water quality requirement is required for this project. The site is located in an aquifer recharge area and the on-site soils will provide the required treatment. 16585.() 63, doc 2.2 Analysis of the Six Special Requirements Special Requirement No. 1: OtherAdopted Area -Specific Requirements, Response: There are no known other adopted area -specific requirements for this area by the City of Renton to the best of our knowledge. Special Requirement No. 2. Flood Hazard Area Delineation. Response: The Black River is located westerly of the project site and has a Flood Hazard Area associated with it. However, none of the 100 -year floodplain is within the project limits on this site. Special Requirement No. 3: Flood Protection Facilities. Response: This Special Requirement is not applicable to this project site. Special Requirement No. 4_ Source Control. Response; The project site parking lot will have to be swept on a regular basis and vacuumed as well in order to maintain the permeability of the asphalt on this project site. There should be no other forms of pollution other than oil and sediment on this area of the overall development. Special Requirement No, 5: Oil Control, Response: This project does not meet the characteristics of a high -use site; therefore, this Special Requirement does not apply. Special Requirement No. b: Aquifer Protection Area. Response: This project is on the outer limit fringe of an Aquifer Protection Area and the on-site soils provide adequate water quality through infiltration through the underlying soil below the permeable asphalt. Therefore; no further lining or aquifer protection requirements apply to this project site. # 6585.003.d oc 3.0 OFF-SITE ANALYSIS 3.0 OFF-SITE ANALYSIS No off-site analysis was prepared for this project site as all runoff generated from the proposed parking lot area will be readily infiltrated, including runoff from any upstream basin draining onto the permeable asphalt_ A small sloped area between the railroad tracks and the permeable asphalt will drain down to the permeable asphalt; however, in the sizing of the pavement section, there is adequate safety measure to infiltrate all stormwater runoff that lands on the permeable asphalt. Therefore, no further upstream or downstream analysis was performed for this project. 16585.003.doc FEMA MAP n l r� 30wLcVAI'D ClrHi��S T �Tti S r C ZONE X LLJ - r ZONEAE Lu C� G REFERENCE: Federal Emergency Management Agency (Portion of Map 5303300976 F, May 1995) 07hER ARFA5 ZONE x Anes dcee"'nad to be ouefide 5Cayear 1cdpiain. Scala: For ; Job N umbet Horizontal: N.T.S. Vertical: WA HARPER ENGINEERING jp14Aj`s 6585 1821572ND AVENUE SOUTH RENTQN, WASHINGTON q• ► KENT, WA 98032 Z (425) 251-6222 Title. - (425) 251-8782 FEMA MAP CIVIL ENGINEERING, LAND PLANNING, <hfNc eraa,HE�� SURVEYING, ENVIRONMENTAL SERVICES ATE: 08!201141 P:146000s1465851exhibiAgraphicstl6585 fema.cdr ASSESSOR'S MAP P:176000s1765654exhibiAyraplvcstl6585 amap.cdr 2^ 126 2dry - 9 15 f \ 2a 10 - 17 I� GA UI 94 fu 52 ' ' 14)j ALTAMONTE Condo 17 ix 1366fe t\ 11 I� 1 , ry9 J E3 tr wP 10 � 2'rgl _1- - " 5 E Ila +r1 +r-�C {{.1c 5F IY _ f[PGCu-.. •-� is f, cl .. 0...3 141 SITE 5 - I Issc3xe[ WC .rs: vcY 927: - I Nin, g, 5 09 1.' �. .1 s7 +5 T{ S.144TH ST - Pol u[ErT',i Is. p'. 11, 9TI ':4'30. mPASev[ sz cane D 5409/slo 'iS. ¢{ ' S. PJ TTH. 67. ]4 37 loll' a - a•P ¢ X59. Fa a3?.2[ 3z 5 Co�ifu p 2fi'.3i .-1 -YS v: - � 3n CC 5 I ff REFERENCE: King County Department of Assessments (May 2014) Seale: Far; Job Number Horizoptak N.T.S. Verflcai ova HARPER ENGINEERING 16685 t4A 1821572ND AVENUE SOUTH RENTON, WASHINGTON KENT, WA 98032 Al ` Z (425) 251-6222 Title: (425) 2518782 _ ASSESSOR MAPj� CIVIL ENGINEERING, LAND PLANNING, 'Ha eHo,SURVEWNG. ENVIRONMENTAL SERVICLS DATE: 08/20/14 P:176000s1765654exhibiAyraplvcstl6585 amap.cdr SENSITIVE AREAS FOLIOS REFERENCE: King County iMAP (2014) Scale HompnW N.T.S. Tyr, 0 r'Yc ENGINE' Vertical NIA 18215 72ND AVENUE SOUTH KENT, WA 98032 (425) 251-5222 (425) 251-8782 CIVIL ENGINEERING. LAND PLANNING, SURVEYING. ENVIRONMENTAL SERVICES Y I5UUOS11658516xhlbli'graphresl16585 ser>s,cdr For:' Title: 2409 Color Aerial Photos (121n) HARPER ENGINEERING RENTON, WASHINGTON SENSITIVE AREAS MAP Job Number 16585 .DATE. 08120;14 Legend County Eburi,"ry SAO Stream SAO Wetland x Mountain Peaks Crag 1 SAO Landslide Highways .! Cul"2aeremi" SAO Coal Mine Streets 1� C4d92U'W-.d SAO Seismic Ilivwav !s/ C1.11Ia3 SAO Erosion "o-zo+ L"W.Modilmd 2009 t;Alo+Aorial Photos Lad lakes and Large Rivers (tin) Parcels Streams REFERENCE: King County iMAP (2014) Scale HompnW N.T.S. Tyr, 0 r'Yc ENGINE' Vertical NIA 18215 72ND AVENUE SOUTH KENT, WA 98032 (425) 251-5222 (425) 251-8782 CIVIL ENGINEERING. LAND PLANNING, SURVEYING. ENVIRONMENTAL SERVICES Y I5UUOS11658516xhlbli'graphresl16585 ser>s,cdr For:' Title: 2409 Color Aerial Photos (121n) HARPER ENGINEERING RENTON, WASHINGTON SENSITIVE AREAS MAP Job Number 16585 .DATE. 08120;14 4.0 FLOW CONTROL AND 'WATER {QUALITY FACILITY ANALYSIS AND DESIGN 4.0 FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN A. Existing Site Hydrology Under existing conditions the site is highly vegetated with second growth forest and brushy areas. There is an existing wetland located in the northwest corner of the project site which the site currently drains to if runoff is not infiltrated or evaporated prior to that. B. Developed Site Hydrology Under developed conditions 24,000 square feet of the site will have permeable asphalt applied with grading occurring in order to provide a parking lot for the proposed use of the existing Harper Engineering development located across the railroad tracks and immediately south of the project site. This permeable asphalt has a pavement section of 10 inches including also the rock and gravel layers below the porous asphalt. This was more than adequate to infiltrate all stormwater runoff generated from the permeable asphalt and any contributing area. Please refer to the calculations on the following pages of this report for how that was sized. C. Performance Standards The King County Runoff Time Series model was utilized in sizing the permeable asphalt pavement section on this project site. The permeable asphalt is a Flow Control BMP which meets the requirements of the City of Renton for projects of this nature. Water quality is not required as the on-site soils exhibit traits of treatment type soils and there is no conveyance system proposed with this development. D. Flow Control System As mentioned previously, the only flow control system proposed for this project is to utilize permeable asphalt as a Flow Control BMP, E. Water Quality System There is no water quality system proposed for this project. 1 6585.6o3.doc KCRTS CALCULATIONS TO SIZE THE POROUS ASPHALT rAIA ve. IT KCRTS Command 1 i 1 J1 } % I� - - - - - - - - - ` - - - r% ��, .,! fJ I �.�jr, CREATE a new Time Series � J/ ------------------------ ProducCion of Runoff Time Series f -a +� "`,c� /S}o r i Project Location Sea -Tac u Comptin Series 16585infildev.tsf Regional Scale Factor 1,00 #1 Data Type Reduced Creating Hourly Time Series File Loading Time Series File:C:\KC_SWDM\KC_DATA\STEI60R.rnf Impervious 0.55 acres -------------- Total Area 0.55 acres Peak Discharge: 0,260 CFS at 6:00 on Jai 9 in Year 8 Storinq Time Series File:16585_nfildev,:�sf Time Series Computed KCRTS Command ------------- Enter the Analysis TOOLS Module ------------------------------- Analysis Tools Command ---------------------- Compute PEAKS and Flow Frequencies ---------------------------------- Loading Stage/Discharge cur_v-e.16585infildev.tst Flow Frequency Analysis -------------------------------------------------------- Time Series File.16585infildev.tsf Project 1,ocation:Sea-Tac Frequencies & Peaks saved to File:16585infildev.pks Analysis Tools Command ----------------------- RETURN to Previous Menu ----------------------- KCRTS Command ------------- Size a Re-tention/Detention FACILITY ----------------------------------- Edit Facility ------------- CANCELLED Retention/Detention Facility Design ----------------------------------- Saving Retention/Detention Facility File:16585infil.rdf End Sizing Retention/Detention Facility KCRTS Command Flow Frequency Analysis Time Series File:16585infildev,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 0.133 7 2/09/01 2:00 0.260 1 100.00 0.990 0.117 8 1/05/02 16:00 0,200 2 25.00 0,960 0.163 4 12/08/02 18:00 0.163 3 10.00 0.900 0.137 6 8/26/04 2:00 0.163 4 5.00 0.800 0.163 3 10/26/04 16:00 0.142 5 3.00 0-667 0.142 5 1/18/06 16:00 0.137 6 2.00 0.500 0.200 2 10/26/06 0:00 0.133 7 1.30 0.231 0.260 1 1/09/08 6:00 0.117 8 1.10 0.091 Comnuted Peaks 0.240 50.00 0.980 Flow Frequency Analysis Time Series Fi7_e.16585infilydout.tsf Project Location;Sea-Tac ---Annual Peak Flow Rates ---- Flow Rate Rank Time of Peak ,CFS) Period 0.000 01000 6 2/09/01 3:00 0.000 8 1./05/02 17:00 0,000 4 2/27/03 8:00 0.000 7 8/25/04 3:00 0.000 3 10/28/04 17:00 0.000 5 1/18/06 14;00 0.000 2 10/25/06 .1:00 0.000 1 1/09/08 10:00 Computed Peaks 0.231 0.000 -----Flow Frequency Analysis ------- - - Peaks - -- Rank Return Prob (CFS) (ft) Period 0.000 0.18 1 100.00 0.990 0.000 0.04 2 25-00 0.960 0.000 0.04 3 10.00 0.900 0.000 0.04 4 5.00 0.800 0.000 0.03 5 3.00 0.667 0.000 0.03 6 2.00 0.500 0,000 0.03 7 1.30 0.231 0.000 0.02 8 1.10 0.091 0,000 0.7.3 50.00 0.980 Retention/Detention Facility Type of Facility: Gravel Infiltration Trench Facility Length: 240.00 ft Facility 79idth; 100.00 ft Facility Area: 24000, sq. ft Effective Storage Depth: 0.83 ft Stage 0 Elevation: 20.17 ft Storage Volume: 5976, cu. ft Vertical Permeability: 200.00 min/in Permeable Surfaces: Bottom Riser Bead: 0,83 ft Riser Diameter: 12,00 inches Top Notch Weir: None Outflow Rating Curve; None Stage Elevation Storage Discharge Percolation (ft) (ft) (cua ft) (ac -ft) (cfs) (cf..$) 0.00 20.17 0. 0.000 0.000 0.00 0.04 20.21 288, 0,007 0.000 0.17 0,08 20.25 576, 0,013 0.000 0,17 0.12 20.29 864, 0,020 0.000 0.17 0.17 20.34 1224. 0.028 0,000 0.17 0.21 20.38 1512. 0,035 0.000 0.17 0.25 20,42 1800. 0,041 0.000 0.17 0.29 20.46 2088. 0.048 0.000 0.17 0.33 20,50 2376. 0.055 0.000 0.17 0.37 20.54 2664, 0.061 0,000 0.17 0.42 20.59 3024. 0,069 0.000 0,17 0.46 20.63 3312. 0,076 0.000 0,17 0.50 20.67 3600, 0.083 0.000 0.17 0.54 20.71 3888, 0.089 0.000 0,17 0.58 20.75 4176. 0,096 0,000 0.17 0.62 20.79 4464, 0.102 0.000 0.17 0.67 20.84 4824. 0.111 0.000 0.17 0.71 20.88 5112, 0,117 C.000 0.17 0.75 20.92 5400, 0,124 0.00C 0.1_7 0.79 20.96 5688, 0.131 0.000 0.17 0,83 21.00 5976. 0,137 0.000 0.17 0,93 21,10 5976. 0.137 0.308 0.17 1.03 21.20 5976. 0.137 0.871 0.17 1.13 21..30 5976. 0,137 1.600 0.17 1,23 21.40 5976. 0.137 2,390 0,17 1.33 21,50 5976. 0.1.37 2.670 0.17 1.43 21.,60 5976, 0,137 2.930 0.17 1..53 21.70 5976, 0.137 3,160 0.17 1.63 21.80 5976. 0,137 3.380 0.117 1.73 21.90 5976. 0.137 3.590 0,17 1.83 22.00 5976. 0.137 3.780 0.17 1,93 22.10 5976. 0.137 3,970 0.17 2.03 22,20 5976, 0.137 4.140 0.17 ---------------------------------- Route Time Series through Facility Inflow Time Series File:165B5infildev.tsf Outflow Time Series File:16585infilydout_t7.f Inflow/Outflow Analysis Peak Inflow Discharge: 2.13 22.30 at 6:00 on Jan 9 in Year 8 5976. 0,137 4.310 0,17 Peak Reservoir Stage: 2.23 22.40 0.000 5976. 0,137 4.470 0,17 Peak Reservoir Storage: 2.33 22.50 -Ft 5976. 0,137 4.630 O,17 7 2.43 22.60 0.000 5976. 0.137 4.780 0.17 5 2.53 22.70 0.000 5976, 0.137 4.930 0,17 1 2.63 22.80 Computed Peaks 5976, 0.137 5.070 0.17 1.10 2.73 22.90 0,13 5976. 0.137 5.210 0.1.7 2.83 23.00 5976. 0.137 5,350 0.17 Hyd Inflow Outflow Peak Storage Target Calc Stage Elev (Cu -Ft) (Ac -Ft) 1 0.26 0.00 0.00 0.18 20.35 1305. 0,030 2 0.14 ******* 0.00 0.03 20.20 230. 0.005 3 0.20 ******* 0.00 0.04 20.21 293, 0.007 4 0.16 ******* 0.00 0.04 20.21 255. 0,006 5 0.16 ******* 0.00 0.04 20.21 264. 0.006 6 0.13 ******* 0.00 0.03 20.20 239_ 0.005 7 0.14 ******* 0.00 0.03 20.20 198. 0.005 8 0.12 ******* 0.00 0,02 20.19 173. 0,004 ---------------------------------- Route Time Series through Facility Inflow Time Series File:165B5infildev.tsf Outflow Time Series File:16585infilydout_t7.f Inflow/Outflow Analysis Peak Inflow Discharge: 0.260 CFS at 6:00 on Jan 9 in Year 8 Peak Outflow Discharge; 0.000 CFS at 10:04 on Jan 9 in Year 8 Peak Reservoir Stage: 0.18 Ft 0.000 Peak Reservoir Elev: 20.35 Ft 0.000 Peak Reservoir Storage: 1305. Cu -Ft 4 0.030 Ac -Ft Flow Frequency Analysis Time Series File:16585infilydout.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) Period 0.000 0.000 6 2/a9/01 3:00 0.000 8 1/05/02 17:00 0.000 4 2/27/03 8:00 0.000 7 8/26/04 3;00 0.000 3 1.0/28/04 17:00 0.000 5 1/18/06 14:00 0.000 2 10/26/06 1:00 0,000 1 1/09/08 10:00 Computed Peaks 0.231 0.000 Flow Frequency Analysis- - - Peaks - - Rank Return Prob (CFS) (ft) Period 0.000 0.18 _ 100.00 0.990 0.000 0.04 2 25.00 0.960 0.000 0.04 3 10.00 0.900 0.0.30 0.04 4 5.00 0.800 0.000 0.03 5 3.00 0.667 0.000 0.03 6 2,00 0.500 0.000 0.03 7 1.30 0.231 0.000 0.02 8 1.10 0.091 0.000 0,13 50.00 0.980 GRADING AND DRAINAGE PLAN 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN 5.0 CONVEYANCE SYSTEM ANALYSIS AND DESIGN As mentioned previously, there is no conveyance proposed for this development; therefore, this section does not apply. 16585.003.doc 6.0 SPECIAL REPORTS AND STUDIES SOILS REPORT August 12, 2014 ES -2004.02 Harper Engineering c/o Craft Architects 2505 Third Avenue, Suite 324 Seattle, Washington 98121 Attention: Mr. Todd Schutz Subject; Geotechnical Evaluation Parking Area Improvements Harper Engineering 700 Southwest 7tn Street Renton, Washington Reference: Craft Architects Parking Addition Plan, Sheet A0.1 Dated June 30, 2014 Dear Mr. Schutz: Earth I Solutions NW LLC Earth Solutions NW LLC Geotechnical Engineering Construction Monitoring Friv renmental Sciences In accordance with you request, Earth Solutions NW, LLC (ESNW) has prepared this geotechnical evaluation letter for the subject property. Project Description The site is located along the north side of Southwest 7th Street in Renton, Washington. The approximate location of the property is delineated on the Vicinity Map (Plate 1). The subject area consists of a triangular-shaped parcel located off the north side of the existing Harper Engineering building. We understand new parking will be constructed in this area. Grades will remain largely unchanged with the exception of the egress which will require constructing a ramp to clear an existing abandoned railway line. The feasibility of infiltrating runoff is also being investigated as part of the project plans. Geotechnical Evaluation Subsurface Conditions An ESNW representative observed, logged and sampled four test pits excavated within the proposed parking area using a backhoe and operator retained by our firm. The approximate locations of the test pits are delineated on the Test Pit Location Plan (Plate 2). A general soil description is provided below. Please refer to the test pit logs for a more detaiied description of the soil and groundwater conditions encountered. 1805 - 136th Place N. F., Suite 201 • Bellevue, WA 98095 q A25) 449-4704 ' FAX (425) 449-4711 Harper Engineering c/o Craft Architects August 12, 2014 ES -2004.02 Page 2 In general, silt (unified Soil Classification Mt_) and silty fine sand (SNI) alluvial deposits were encountered at the test pit locations. The silt was the predominate soil deposit and was observed to be in a loose to medium dense condition. The silty sand was encountered at test pit location TP -4 and was overlying a silt deposit. Groundwater seepage was observed at test pit location TP -4 at a depth of about eight and one- half feet below existing grade. This seepage likely represents the local groundwater table given the proximity of a local stream abutting the north property line, and we would expect the leve! to rise during the rainy Fall -Spring months. Infiltration Recommendations We conducted three EPA falling head infiltration tests within the native soil deposits, generally at a depth of about three feet below existing grades. The infiltration tests were performed at test pit locations TP -1 through TP -3. Based on the results of the testing, average unfactored infiltration rates of 1.0 inch/hour (TP -2 and TP -3) and 4,0 inches/hour (TP -1) were measured. USDA textural analysis of representative soil samples yielded a loam classification, with fines contents ranging from about 87 to 94 percent passing the No. 200 sieve. In our opinion, for preliminary site designs, a factored infiltration rate of 0.3 inchthour can be used for LID elements. Due to the low infiltration rate, an overflow provision should be included in designs. Based on the groundwater conditions observed during the fieldwork, infiltration facilities should not extend below about three feet relative to existing grades. This provision is based on an estimate of seasonal Nigh groundwater that rises 2.5 feet from the level observed during the fieldwork of 8.5 feet and a separation of 3.0 feet. Pavement Recommendations Pavement recommendations in this section are for preliminary design considerations. It is assumed that the majority of the traffic loading will consist of passenger vehicles, but that occasional heavy trucks may use the area. To ensure adequate pavement performance, the subgrade should be in a firm and unyielding condition when subjected to proofrolling with a loaded dump truck. Structural fill in pavement areas should be compacted to the specifications detailed in the "Site Preparation and Earthwork" section of this report. It is possible that soft, wet, or otherwise unsuitable subgrade areas may still exist after base grading activities. Areas containing unsuitable or yielding subgrade conditions will require remedial measures such as cement treatment, overexcavation and thicker crushed rock or structural fill sections prior to pavement. For relatively lightly loaded pavements subjected to automobiles, the following pavement sections can be considered: • Two inches of not mix asphalt (HMA) placed over four inches of crushed rock base (CRB), or; • Two inches of HMA placed over three inches of asphalt treated base (ATB). Earth Solutions Nw, LLC Harper Engineering c/o Craft Architects August 12, 2014 ES -2004.02 Page 3 Heavier traffic areas subjected to occasional truck traffic generally require thicker pavement sections depending on site usage, pavement life expectancy, and site traffic. For preliminary design purposes, the following pavement sections can be considered for these areas. • Three inches of HMA placed over six inches of CRIB, or; Three inches of AC placed over four and one-half inches of ATB. The HMA, ATB and CRB materials should conform to 1NSDOT specifications. City of Renton Road Standards may supersede the recommendations provided in this document. Railroad Crossing Easement Egress will be provided via a crossing easement that will extend over the railroad tracks. The majority of the crossing will be supported by railroad ballast fill. In this respect, roadway support should be good, In general, areas outside the existing railroad ballast fill should be prepared in a similar manner as those described in the pavement section above. There is the potential for differential settlement at the transition between the ballast fill and general site fill. The roadway fill will taper as it extends outside the railroad alignment and this will reduce the differential settlement to some degree, To further mitigate the effects of differential settlement in the egress area, a woven geotextile such as Wrafi 60OX can be used under new fill areas. The geotextile should be placed such that it extends at least 10 feet into the ballast fill area and 20 feet into the areas outside ballast fill. Cement treatment of the soils outside the ballast area can be considered in lieu of using a geotextile. We trust this letter meets your current needs information is required, please call. Sincerely, EARTH SOLUTIONS NW, LLC c tt S ie el, L. , L. ojec anager Attachments: Plate 1 — Vicinity Map Plate 2 — Test Pit Location Plan Test Pit Logs (TP -1 through TP -4) If you have any questions, or if additional �. CA Mp � Qt WASJ�+! o IQNAI- �- �'o Kyle R. Campbell, P.E. Principal Earth Solutlons NW, LLC rITT,. tel f. _}} t r =T r s All! l ,► Y } 4{[; !UC vi r aF 1jA SS, ;S .5 fi 5N ILr ! ..... . . . . . . MR X IV AT 124 C" + J A617T •t x'4 y r s{ k � n S r � R "4• �Y � i.s i F ''' � �• ��� � pmt tel' i14�1F-- :r 4 f-vm�t S' 2991, Fk 25 s r NORTH Reference: King County, Washington Map 656 By The Thomas Guide Vicinity Map Rand McNally Harper Engineering Parking Addition 32nd Edition Renton, WasWngton NOTE: This plate may contain areas of color. ESNW cannot be Drt^rn. GLS Date 08/1112014 Proj, No. 2004.02 responsible ;or any subsequent misinterpretation of the information Checked SHA Date Aug. 2014 1 Plate 1 resulting from black & white reproductions of this plate. i_ - M 25' Bulfer TP -31 LI ITP- TP -1 Existing Building LEGEND NORTH TP -1 —!—Approximate Location of ESNW Test Pit, Prod. No. ES -2004.02, July 2014 Subject Site 30 60 120 Existing Building =60Scale in Feet Wetland Area (Delineated By Others) r NOTE The graphics shown on this plate are not intended for design purposes or precise scale measuremerls, but only to illustrate the approximate test locations relative to the approximate locations of Test Pit Location Plan exlsting and 1 or proposed site features. The information illustrated is largely based on data provided by the ch'ent at the time of our Harper Engineering Parking Addition study ESNW cannot be responsible for subsequent design changes Renton, Washington or interpratalion of the data by others. Drwn. GLS Date 0811112014Proj. No. 2004.02 NOTE: This plate may contain areas of color. ESNW cannot be responsible for any subsequent misinterpretation of the information Checked SHA Date Aug. 20141 Plate 2 resulting from black 8 white reproductions of this plate. Earth Solutions NWLLC SOIL. CLASSIFICATION CHART MAJOR DIVISIONS SYMBOLS TYPICAL DESCRIPTIONS GRAPH ILETTERI GRAVEL AND CLEAN•r- GRAVELS ••r• ��•� ID •* GIN WELL -GRADED GRAVELS, GRAVEL - SAND MIXTURES, LITTLE OR NO GRAVELLY SOILS (LITTLE OR NO FINES) o pOQ Q Q Q u0 GP POORLY -GRADED GRAVELS, GRAVEL - SAND MIXTLlRFS, LITTLE OR NO FINES COARSE GRAINED SOILS MORETFIAN50°1 OF COARSE FRACTION GRAVELS WITH FINES o ° o 6 GM SiLTYGRAVELS,GRAVEL-SAND- SILT MIXTURES RETAINED ON NO, 4 SIEVE (APPREC[ABLEG+�+ AMOUNT OF FINES) CLAYEY GRAVELS, GRAVEL - SAND - CLAY MIXTURES MORE THAN 54% OF MATERIAL IS SAND AND CLEAN SANDS ��xW WELL -GRACED SANDS, GRAVELLY SANDS, LITTLE OR NO FINES LARGER THAN SANDY NO, 204 SIEVE SIZE SOILS (LITTLE OR NO FINES] SP POORLY -GRADED SANDS, GRAVELLY SAND, LITTLE OR NO FINES SANDS WITH FINES SM SILTY SANDS, SAND -SILT MIXTURES MORE THAN 50"1° OF COARSE FRACTION PASSING ON NO - 4 SIEVE (APPRECIABLE AMOUNT OF FINES) SC CLAYEY SANDS, SAND - CLAY MIXTURES INORGANIC SILTS AND VERY FINE ML SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY SILTS INORGANIC CLAYS OF LOW TO FINE GRAINED SOILS AND LIQUID LIMIT CLAYS LESS THAN SU �� M£DIUV PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS OL ORGANIC SILTS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY MORE THAN 50% OF MATERIAL 1S SMALLER THAN NO. 200 SIEVE MH INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE SAND OR SILTY SOILS slxF_ SILTS LIQUID LIMIT AND AND GREATERTHAN 50 CLAYOH �+I I INORGANIC CLAYS OF HIGH PLASTICITY ORGANIC CLAYS OF MEDIUM TO NIGH PLASTICITY, ORGANIC SILTS .yam.,. HIGHLY ORGANIC SOILS d i, 1 f, ++, y PT PEAT, HUMUS, SWAMP SOILS WITH HIGH ORGANIC CONTENTS DUAL SYMBOLS are Used to indicate borderline soil classifications. The discussion in the text of this report is necessary for a proper understanding of the nature of the material presented in the attached logs, Earth Solutions NW TEST PIT NUMBER TP -'1 ' 1805 - 136th Place N.E., Suite 201 Bellevue, Washington 98005 PAGE 1 OF 1 Telephone: 4254494704 Fax: 425-449-4711 CLIENT Harper Engineering _ _ PROJECT NAME _Har ep r Engineerillq Parking Addition PROJECT NUMBER 2004-2 PROJECT LOCATION Rentons Washington DATE STARTEQ 7129114 COMPLETED 7129114 GROUND ELEVAT3ON TEST PIT SIZE EXCAVATION CONTRACTOR Watterson Excavatingr_____ GROUND WATER LEVELS: EXCAVATION METHOD AT TIME OF EXCAVATION LOGGED BY SHA CHECKED BY SHA AT END OF EXCAVATION — NOTES Depth of Topsoil & Sod 8": blackberry bushes AFTER EXCAVATION — W a. DL 0 Lu L TESTS 6 J MATERIAL DESCRIPTION Q a-� a z C9 0 T P S L 0.5 TOPSOIL Brown SILT, stiff, moist [USDA Classification: tan LOAM] MC = 25.00% Fines = 87.40% 5 MC = 36.90% ML -light 4ron oxide staining -sand lensing 1❑ 100 Test pit terminated at 10.0 feet below existing grade. No groundwater encountered during excavation. Bottom of test pit at 10.0 feet. Earth Solutions NW TEST PIT NUMBER TP-2 1805 _ 136th P€ace N.E., Suite 201 U'R va Beitevue, Washitlgtor 98005 PAGE 1 OF 1 Seieph one: 425-449-4704 Fax: 426-449-4711 CLIENT _Harper En ineerin V PROJECT NAME Harper Engineering Parking Addition PROJECT NUMBER 2604-2 PROJECT LOCATION Renton Washington - DATE STARTED 7129!14 _ COMPLETED 7129114 GROUND ELEVATION TEST PIT SIZE EXCAVATION CONTRACTOR UVatterson Excavating_ _ GROUND WATER LEVELS: EXCAVATION ME=THOD AT TIME OF EXCAVATION -- _ LOGGED BY SHA CHECKED BY SHA AT END OF EXCAVATION -- NOTES Depth of Topsoil & Sod 8": blackberry bushes AFTER EXCAVATION u� z �ul Lua j TESTS p MATERIAL DESCRIPTION z � Q 0 TPSL `-' 0.5 TOPSOIL Brawn SILT, diff, moist _ MC = 37.013% _6 ML -increased silt content MC = 33,Cc% -sand lanvrg, increased moisture content 10 Test pit terminated at 11.0 feet below existing grade, No groundwater encountered during excavat+Dn- Bottom of test pit at 11.D feet y Earth Sotuerons NW TEST PIT NUMBER TP -3 1805 - 136th Place N.E., Suite 201 Waw Bellevue, Washington 98005 PAGE 1 OF 1 % Telephone: 425-449-4704 % Fax; 425-449-4711 CLIENT Hamer EngineeringW — PROJECT NAME Hammer En4ineering Parking PROJECT NUMBER 2004-2 _---.-_--- PROJECT LOCATION Renton, Washington ----_---�—__- — - -- DATE STARTED _7129/14 l COMPLETED 7129/14 GROUND ELEVATION TEST PIT SIZE W EXCAVATION CONTRACTOR Watterson t=xcavatirag GROUND WATER LEVELS: EXCAVATION METHOD - —-_----_—..�_—_._..----_-- AT TIME OF EXCAVATION�—Y— LOGGED BY __SHA CHECKER BY SHA _ AT END OF EXCAVATION NOTES Depth of Topsoil. E, Sod 8", bare soil _ AFTER EXCAVATION w L U V t-LLI2 TESTS V Q O MATERIAL DESCRIPT[ON 0.� 2 z _j La a TPSL—= o.s TOPSOIL Brown SILT, stiff, moist - Mi: M 18.20°fo becomes very stiff, light iron oxide staining 5 ML 9.0 Test pit terminated at 9.0 feet below existing grade. No groundwater encountered during excavation. Bottom of test pit at 9,0 feet. Earth Solutions NW TEST PIT NUMBER TP -4 1805 - 136th Place N E., Suite 201 ' Bellevue, Washington 98005 PAGE 4 OF 1 Telephone: 425-449-4704 Fax: 425-449-4711 i CLIENT Harper Engineering , PROJECT NAME Mail er Engineering Par;<ing Addition PROJECT NUMBER 2004-2 PROJECT LOCATION Renton, 1NashingSan DATE STARTED 7/2$114 COMPLETED 7129/14 GROUND ELEVATION mm _ _ TEST PIT SIZE EXCAVATION CONTRACTOR Watterson Excavating GROUND WATER LEVELS: EXCAVATION METHOD Q AT -nME OF EXCAVATION 8.6 ft LOGGED BY SHA CHECKED BY SHA AT END OF EXCAVAVON — NOTES - Depth of Topsoil & Sod 8 bare soil AFTER EXCAVATION -- ut rr w a a 2 TESTS 'o n 00 MATERfAL DESCRIPTION LU a.= J az 0 0 MC = 35.40% SM TOPSOIL Brown silty SAND, medium dense, moist MC = 40.10% Hh�e,0 Fines = 94.10% 1 Gray SILT, medium stiff, moist to wet ML 8.5 D [USDA Classification: gray LOAM] MC = 41.00% Sp Brown poorly graded SAND with silt, medium dense to dense, wet \X Test sit terrninate-d at 103.0 feet below existing grade. Groundwater table encountered at 8.5 feet during excavation. Bottom of test pii at 10.0 feet. Earth Solutions NW GRAIN SIZE DIST RIBLITIO 1805- 136th Place N.E., Suite 201 Bellevue, WA 98005 Telephone; 425-284-3300 CLIENT Ha exp r En9ineein- Uo Craft Architects_ i PROJECT NAME Harper Engineefinq PROJECT NUMBER ES -2004.02 _ _ PROJECT LOCATION Renton ^ U.S. SIEVE OPENING IN INCHES I U S, SIEVE NUMBERS ) HYDROMETER 101 91 9C 8E SC 75 70 65 a Ua 60 } y � 55 m � 50 z z 45 LLA 40 ul a- 35 30 25 20 15 10 5 n 6 4 3 2 1.5 1 314 112310 3 6 s 14 20ZQ 40 50 80 100140 204 - a ! 1� I I 100 10 1 0.1 0.01 0.0 GRAIN SIZE IN MILLIMETERS COBBLES GRAVEL SAND - coarse Itne coarse medium fine Specimen Identification Classification O TP -1 30t. USDA: Tan Foam. USCS: Silt, ML_ M TP -4 6.Oft. USDA: Gray Loam. USCS: Silt, MF. Specimen Identification o TP -1 3.0ft. i TP -4 — 6.Oft. D100 4.75 2 X.i �1 i SILT OR CLAY IIS LL I PL I Pi I Cc I Cu %Gravel %Sand %Sift 0.0 1 2.6 87.4 0.4 5.9 94.1 7.0 OTHER PERMITS 7.0 OTHER PERMITS Other permits for this project site include'. Clear and Grade Permit Site Development Permit 16585.003.doc a:. . •III 8.0 CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN (CSWPPP) ANALYSIS AND DESIGN A. Erosion and Sediment Control (ESC) Plan Analysis and Design The 2009 King County Surface Water Design Manual Appendix D as modified by the City of Renton will be followed in providing erosion control facilities for this project site. Cover measures are specified, clearing limits are shown, and perimeter protection in the form of silt fence will be installed around the perimeter of the site This site Is less than 1 acre in size for the area that is being developed. Therefore, a sediment trap er sediment pend is not required; also because the on-site soils will likely infiltrate runoff that lands on them unless it becomes concentrated. Then, the silt fence Will act a deterrent to the spreading of sediment -laden water downstream. In addition, on the downstream side of the silt fence is thick vegetation that will act as dispersion for runoff from this project site. B. Stormwater Pollution Prevention and Spill (SWPPS) Plan Design When the pavement placement machine is on the site it will have to be maintained. An oil spill could occur; however, the maintenance of this device must be performed over an impermeable liner area of the site 'm order to prevent contaminants from entering the groundwater. In addition, concrete will be poured to provide extruded curb surrounding the perimeter of the asphalt pavement. There could be pollutants discharged with the cleaning of the concrete truck; however, this will have to occur in a location that can be cleaned up readily with no impact to the aquifer from concrete. Those are the only anticipated pollution -creating sources on the project site. 16585.003.doc 9.0 BOND QUANTITIES, FACILITIES SUMMARIES, AND DECLARATION OF COVENANT THESE ITEMS WILL BE SUBMITTED WITH THE FINAL TIR PREPARED FOR THIS PROJECT 10.0 OPERATIONS AND MAINTENANCE MANUAL AN OPERATIONS AND MAINTENANCE MANUAL WILL BE PREPARED WITH THE FINAL TIR PREPARED FOR THIS PROJECT