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HomeMy WebLinkAboutLUA-07-077_MiscTECHNICAL INFORMATION REPORT Proposed Harper Engineering Building and Parking Lot NWC -S.W. 7th Street and Seneca Avenue S.W. Renton, Washington Prepared for: Harper Engineering Co. 206 South Tobin Street Renton, WA 98055 July 6, 2007 Our Job No. 12948 -7-0 J CIVIL ENGINEERING, LAND PLANNING, SURVEYING, ENVIRONMENTAL SERVICES 18215 72ND AVENUE SOUTH KENT, WA 98032 (425) 251 ·6222 (425) 251-8782 FAX BRANCH OFFICES + OLYMPIA, WA + TACOMA, WA + SACRAMENTO, CA + TEMECULA, CA www.barghausen.com 1.0 INTRODUCTION/GENERAL INFORMATION 1.0 INTRODUCTION/GENERALINFORMATION The proposed project site is approximately 2.21 acres in size located on the northwest comer of S. W. 7th Street and Seneca Avenue S.W. within the City of Renton. More particularly, the site is located within a portion of the Southwest quarter of Section 18, Township 23 North, Range 5 East, Willamette Meridian, City of Renton, Washington. The site is fairly triangular in shape with a large curving side located along the northern property line of the site, which is adjacent to a railroad right-of-way. S.W. 7th Street forms the project site's southern boundary and there is an existing development located east of the project site. This is a redevelopment project currently consisting of parking lot and landscaping areas. The proposal for this development is to modify the parking lot to construct a new building for the proposed Harper Engineering manufacturing and office space located in the central portion of the project site. Portions of the parking lot will remain intact and portions of the parking lot will be replaced with new parking lot surfacing. The total area of impervious surface subject to vehicular traffic will be substantially reduced with this project. There is already an existing conveyance system located on the site that routes all stormwater runoff into a detention vault sized in accordance with the 1990 King County, Washington Surface Water Design Manual (KCSWDM) in March of 2001. Please refer to the grading and drainage plan located on the next page of this report for an explanation of how the site will be configured under the new developed conditions. Since this project site is not increasing the amount of impervious surface by more than 5,000 square feet, and since it is also decreasing the amount of impervious surface subject to vehicular traffic, there are no modifications proposed to the detention vault located in the center portion of the project site, which discharges into S.W. 7th Street. As mentioned previously, minor modifications will be made to the conveyance system and, since catch basins are being added, the conveyance system will likely be more than sufficient to convey runoff from the project site to the existing conveyance system since all pipes are proposed to be 12-inch. The Technical Information Report for the original parking lot development is attached herewith in Appendix A. Please refer to that document for how the on-site facilities were sized for this project. The total increase in impervious surface with this project is 3,563 square feet= 0.08 acre. 12948.001.doc GRADING AND STORM DRAINAGE PLAN z <( ....J a.. w 0 <( ~ z <( uJ "' a: ~ 0 z ::'2 ~ a: ~ ~ Ji z CJ) ~ 0 z st ;:a- <( ~ 0 z 0 <( a: 0 I' 0 0 N' ·' ~. 0 !l>id',c iHdS\' 83t Bv6ZL Bv6ZL ON sor 3:::>B ! t . ,,/ APPENDIX A TECHNICAL INFORMATION REPORT Puget Sound Electrical Apprenticeship and Training Program Renton, Washington March 19, 2001 Our Job No. 7976 CIVIL ENGINEERING, LAND PLANNING, SURVEYING, ENVIRONMENT AL SERVICES 18215 72NDAVENUE SOUTH, KENT, WA 98032 • (425) 251-6222 • (425) 251-8782 FAX www.barghausen.com TABLE OF CONTENTS I. PROJECT OVERVIEW A. Technical Infonnation Report Worksheet IL PRELIMINARY CONDITIONS SUMMARY III. OFF-SITE ANALYSIS A. Upstream Drainage Analysis B. Downstream Drainage Analysis IV. DETENTION VAULT ANALYSIS AND DESIGN A. Detention Vault Calculations B. Pre-Developed and Post-Developed Basin Area Maps C. Wet Vault Calculations V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN A. Piped Conveyance Calculations B. Conveyance Area Map C. Miscellaneous Conveyance Calculations for Overflow Spillways, Stand Pipes, etc. VI. SPECIAL REPORTS AND STUDIES VII. BASIN AND COMMUNITY PLAN AREAS VIII. OTHER PERMITS IX. EROSION/SEDIMENTATION CONTROL DESIGN X. ADDITIONAL DOCUMENTS A. Retention/Detention Facility Summary Sheet and Sketch XI. MAINTENANCE AND OPERATIONS MANUAL 7976.003 [DED/mmlkn) I. PROJECT OVERVIEW I. PROJECT OVERVIEW The proposed project is located in the southwest quarter of Section! 8, Township 23 North, Range 5 East, Willamette Meridian, within the city of Renton, Washington. More specifically, the site is located along S. W. 7th Street near the intersection with Thomas Avenue. The site is approximately 2.2 I acres in size, and is triangular in shape with approximately 260 feet of frontage along S.W. 7th Street. The site is generally flat, sloping gently toward the north comer. The site is bounded along the north and west sides by existing Burlington Northern Railroad right-of-way. The existing vegetation on site consists ofbrush and low growing ground cover. The site is currently not being used, and contains no existing structures. The proposal for this parcel of land is to construct a new parking lot containing 200 parking stalls. This parking lot will be used by an adjacent building that is being expanded and is requiring additional parking. The stormwater runoff created from this parking lot addition will be handled using a piped conveyance system. Once stormwater enters this conveyance system, it will then be conveyed to a detention vault that is located on site. This underground vault will provide water quality and detention, releasing the stormwater at pre-developed rates. Please see Section IV of this report for further details regarding the storm system and calculations. 7976.003 [DED/mm/lcn] A. TECHNICAL INFORMATION REPORT WORKSHEET King County Department of Development and Environmental Services TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Project Owner Puget Sound Electrical Apprenticeship and Training Trust Address 5700-6th Avenue South. Suite 200 Seattle WA 981 08 Phone _ __,_(2ee0e,6c..l_,_7"'63"--_,_7,..,75,,,5'-------- Project Engineer Hal P. Grubb P.E. Company Barghausen Consulting Engineers. Inc. Address/Phone 18215 -72nd Avenue South Kent. Washington 98032 (425) 251-6222 Project Name Puget Sound Electrical Apprenticeship and Training Trust Location Township. __ _,2,,3e.cN,__ ____ _ Range ___ ~5~E'------- Section. ___ _.:;18"'------ Project Size. __ ~2=.1~ac=r=es,,__ _____ _ Upstream Drainage Basin Size O acres Part 3 TYPE OF PERMIT Part 4 OTHER REVIEWS ANO PERMITS . . APPLICATION D Subdivision HPA D DFWHPA D Shoreline Management D Short Subdivision D COE 404 D Rockery • Grading D DOE Dam Safety • Structural Vaults D Commercial D FEMA Floodplain 0 Other D Other D COE Wetlands Part 5 SITE COMMUNITY AND DRAINAGE BASIN Community Green River Valley Drainage Basin Green River 7976.003 [OED/mm/kn] 0 River 0 Stream 0 Critical Stream Reach • Depressions 0 Lake 0 Steep Slopes Part7 SOILS Soil Type Slopes 0 Additional Sheets Attached Part 8 DEVELOPMENT LIMITATIONS REFERENCE o. _____________ _ o. ____________ _ o. _____________ _ o. ____________ _ 0 Additional Sheets Attached Part 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION 0 Sedimentation Facilities • Stabilized construction Entrance • Perimeter Runoff control 0 Clearing and Grading Restrictions • Cover Practices • Construction Sequence 0 Other . -~· 0 Floodplain 0 Wetlands 0 Seeps/Springs 0 High Groundwater Table 0 Groundwater Recharge 0 Other . Erosion Potential Erosive Velocities LIMITATION/SITE CONSTRAINT · .. • MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION • Stabilize Exposed Surface . . • Remove and Restore Temporary ESC Facilities • Clean and Remove all Silt and Debris • Ensure Operation of Permanent Facilities 0 Flag Limits of SAO and open space preservation areas 0 Other 7976.003 [DED/mmlkn] . 0 Grass Lined Channel 0 • Pipe System • 0 Open Channel 0 0 Dry Pond 0 • Wet Vault 0 Tank 0 Vault 0 Energy Dissipater 0 Wetland 0 Stream 0 Infiltration Depression Flow Dispersal Waiver Regional Detention Method of Analysis SBUH Compensation/Mitigation of Eliminated Site Storage Brief Description of System Operation Stormwater controlled by catch basins and conveyed via pipes to underground vault for detention and water quality. Facility Related Site Limitations Reference Facility Part 11 STRUCTURAL ANALYSIS 0 Cast in Place Vault 0 Retaining Wall 0 Rockery >4' High 0 Structural on Steep Slope 0 Other Limitation Part 12 EASEMENTS/fRACTS 0 Drainage Easement 0 Access Easement . 0 Native Growth Protection Easement 0 Tract 0 Other Part 13 SIGNATURE OF PROFESSIONAL ENGINEER .... ~-·. -. _ _.,-·:_ I or a civil engineer under by supervision have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attachments. To the best of my knowledge the information provided herey;,ur~~ ~g /., ~--,. z.v .. 1:> / Signed/Date 7976.003 IDED/mm/kn] II. PRELIMINARY CONDITIONS SUMMARY II. PRELIMINARY CONDITIONS SUMMARY There arc no conditions for this project. 7976.003 [DED/mm/kn] ill. OFF-SITEANALYSIS III. OFF-SITE ANALYSIS A. UPSTREAM DRAINAGE ANALYSIS The existing topography around the site is such that the site receives very little upstream drainage. As previously mentioned, the site is bounded on the north and west sides by an existing railroad, which sits higher in elevation than the subject property. However, there is only a small amount of area between the site and the existing railroad tracks that actually drains onto the subject property. The adjacent parcel to the east is currently developed and contains all stormwater runoff, with the exception of a small portion at the north side along the existing railroad tracks. Along the south side of the subject property is S.W. 7th Street, which is developed and has storm drainage system that contains all stormwater runoff. B. DOWNSTREAMDRAINAGEANALYSIS The existing topography of the site is such that there is no downstream drainage system. Currently, the stormwater appears to infiltrate on site. If the stormwater was to pond on site, it would eventually overflow at the southwest corner of the site ( which is the lowest elevation along the boundary) into the existing storm system in S. W. 7th Avenue. Stormwater that is collected on site will be detained and treated prior to being released into an existing 60-inch concrete storm line within S. W. 7th Street. We are currently in the process of obtaining specific information about this downstream system. Once this information is available, it will be included within this report. 7976.003 [OED/mm/kn] IV. DETENTION VAULT ANALYSIS AND DESIGN IV. DETENTION VAULT ANALYSIS AND DESIGN Storm drainage that will be produced by the new parking lot will be controlled and conveyed via underground pipes to an underground detention vault located on site adjacent to S. W. 7th Street. This underground vault will provide the required water quality treatment and detention. More specifically, this system has been sized using the 1990 King County Surface Water Design Manual. The enclosed calculations show that the system has been designed to detain the 2-year post-developed storm while releasing the 2-year pre-developed storm, and to detain the 10-year post-developed storm while releasing the JO-year pre-developed storm, along with a volume increase of 30 percent. Calculations have also been provided to verify that the 100-year post-developed storm event will be adequately conveyed through the proposed system. The water quality portion of this vault has also been sized using the same manual. The proposed project will create greater than 1 acre of new impervious area subject to vehicular traffic. Typically, a bioswale along with a wet pond is required; however, with the proposed layout, a bioswale is not feasible. We are proposing an increase in the wet pool volume to compensate for not providing a bioswale. This increase is 1.5 times the required volume. We had a similar situation on a recent City of Renton project that was approved. Please see the enclosed calculations for further details. Based on U.S. Department of Agriculture maps, the soils classification for this site is Wo (Woodinville silt loam). For the drainage calculations, this converts to a hydrologic group "D." 7976.003 [DED/nnnlkn] iwl~ 4/26/01 12:48:43 am DETENTION VAULT CALCS FILE No. 7976-VLT Shareware Release PSEA&TP page 1 ----------------=---------======----------====-=-=---------------=-== BASIN ID: Al SBUH METHODOLOGY TOTAL AREA ....... : RAINFALL TYPE .... : PRECIPITATION .... : TIME INTERVAL .... : ABSTRACTION COEFF: TcReach -Sheet L: TcReach -Shallow L: PEAK RATE: 0.19 cfs BASIN SUMMARY NAME: 2YR PRE-DEV 2.21 Acres KC24HR 2.00 inches 10. 00 min BASEFLOWS: AREA .. : CN .... : TC .... : o.oo cfs PERV 2.21 Acres 86.00 64.39 min 0.20 300.00 80.00 VOL: ns:0.2400 p2yr: 2.00 ks:11.00 s:0.0079 0.16 Ac-ft TIME: s:0.0079 500 min BASIN ID: A2 NAME: lOYR PRE-DEV -:s=-=B=-=UH="""'M=-==E=TH=o-=Dc::0:-::L-:O:-:G=:Y-:-----------------. TOTAL AREA ....... : 2.21 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... : KC24HR PERV PRECIPITATION .... : 2.90 inches AREA .. : 2.21 TIME INTERVAL .... : 10.00 ABSTRACTION COEFF: 0.20 PEAK RATE: 0.42 cfs VOL: BASIN ID: A3 NAME: SBUH METHODOLOGY min CN .... : 86.00 TC .... : 64.39 0.29 Ac-ft TIME: lOOYR PRE-DEV Acres min 490 min TOTAL AREA ....... : 2.21 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... : KC24HR PERV PRECIPITATION .... : 3.90 inches AREA .. : 2.21 Acres TIME INTERVAL .... : 10.00 min CN .... : 86.00 TC .... : 64.39 min ABSTRACTION COEFF: 0.20 EEAK RATE: 0.70 cfs VOL: 0.45 Ac-ft TIME: 490 min BASIN ID: Bl SBUH METHODOLOGY TOTAL AREA ....... : RAINFALL TYPE .... : PRECIPITATION .... : TIME INTERVAL .... : ABSTRACTION COEFF: TcReach -Sheet L: TcReach -Shallow L: TcReach -Channel L: rcReach -Channel L: PEAK RATE: 0.94 cfs NAME: 2YR POST-DEV 2.21 Acres BASEFLOWS: 0.00 cfs KC24HR PERV 2.00 inches AREA .. : 0.42 Acres 10.00 0.20 50.00 125.00 297.00 90.00 VOL: min CN .... : 90.00 TC .... : 8.81 min ns:0.1500 p2yr: 2.00 ks:27.00 S:0.0100 kc:21.00 s:0.0062 kc:21.00 S:0.0239 s:0.0600 0.30 Ac-ft TIME: 480 min IMP o.oo Acres 0.00 0.00 min IMP 0.00 Acres 0.00 0.00 min IMP 0.00 Acres 0.00 0.00 min IMP 1. 79 Acres 98.00 8.81 min 4/26/01 12:48:43 am DETENTION VAULT CALCS FILE No. 7976-VLT • Shareware Release PSEA&TP page 2 -==--=====--===-=====-===----=========----=====-====--=====--==----== BASIN SUMMARY BASIN ID: B2 NAME: lOYR POST-DEV SBUH METHODOLOGY TOTAL AREA ....... : 2.21 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... : KC24HR PERV PRECIPITATION .... : 2.90 inches AREA .. : 0.42 Acres TIME INTERVAL .... : 10.00 min CN .... : 90.00 TC .... : 8.81 min ABSTRACTION COEFF: 0.20 PEAK RATE: 1.43 cfs VOL: 0.46 Ac-ft TIME: 480 min BASIN ID: B3 SBUH METHODOLOGY TOTAL AREA ....... : RAINFALL TYPE .... : PRECIPITATION .... : TIME INTERVAL .... : NAME: lOOYR POST-DEV 2.21 Acres KC24HR 3.90 inches 10.00 min BASEFLOWS: AREA .. : CN .... : TC .... : o.oo cfs PERV 0.42 Acres 90.00 8.81 min ABSTRACTION COEFF: 0.20 PEAK RATE: 1.97 cfs VOL: 0.65 Ac-ft TIME: 480 min BASIN ID: Cl NAME: 64% 2YR POST-DEV (WETVAULT) SBUH METHODOLOGY TOTAL AREA ....... : 2.21 Acres BASEFLOWS: 0.00 cfs RAINFALL TYPE .... : KC24HR PERV PRECIPITATION .... : 0.67 inches AREA .. : 0.42 Acres TIME INTERVAL .... : 10.00 min CN .... : 90.00 TC .... : 8.81 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.23 cfs VOL: 0.08 Ac-ft TIME: 480 min IMP 1. 79 Acres 98.00 8.81 min IMP l.79 Acres 98.00 8.81 min IMP l.79 Acres 98.00 8.81 min 4/26/01 12:48:43 am DETENTION VAULT CALCS FILE No. 7976-VLT Shareware Release PSEA&TP page -----=========---=================================-----------------== HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf\AcFt Acres ==========-------========================-=== 1 0.193 500 6811 cf 2.21 '2. Y,t. Pit€. 2 0.417 490 12652 cf 2.21 IOY!l ~ 3 0.696 490 19702 cf 2.21 I ooY/2. f'0.... 4 0.938 480 13205 cf 2.21 tY~ FW>f 5 1.429 480 20234 cf 2.21 1o'((l f'l>S.-r 6 1.974 480 28132 cf 2.21 /00~ f'OS( 7 0.228 480 3287 cf 2.21 1,,,1,1-nt Pof>f" 8 0.193 670 13205 cf 2.21 1. -rie (2w"1't.() 9 0.417 540 20234 cf 2.21 IO 'ft. (Zo\.)'flc 10 0.177 770 13205 cf 2.21 '2. \"12. Fi r-'M.. 11 0.343 550 20234 cf 2.21 l (l'C(l fi ,..r/n., 12 1.974 490 21066 cf 2.21 I llb'ft.-C,Afp- 3 4/26/01 12:48:44 am DETENTION VAULT CALCS FILE No. 7976-VLT Shareware Release PSEA&TP STAGE STORAGE TABLE RECTANGULAR VAULT ID No. 1 Description: VAULT {W/0 30%) '--'---,=',-Length: 75.00 ft. Width: 18.00 ft. voids: 1. 000 STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf-----Ac-Ft-(ft) ---cf-----Ac-Ft-(ft) ---cf-----Ac-Ft-(ft) ---cf-----Ac-Ft- page ==-----=-------------------~~=~~~--~:~=-~~~~~~=~~-----=-=------------=---~---~-------------------~~----- 16. 00 0.0000 0.0000 17.70 2295 0. 0527 19 .40 4590 0 .1054 21.10 6885 0.1581 Hi.10 135.00 0.0031 17,80 2430 0.0558 19 .50 4725 0.1085 21.20 7020 0.1612 16.20 270.00 0.0062 17. 90 2565 0.0589 19.60 4860 0 .1116 21.30 7155 0.1643 16 .30 405.00 0. 0093 18.00 2700 0.0620 19. 70 4995 0.1147 21.40 7290 0.1674 16.40 540. 00 0.0124 18.10 2835 0.0651 19.60 5130 0.1176 21.50 7425 0 .1705 16. 50 675.00 0.0155 18 20 2970 0.0682 19.90 5265 0 .1209 21.60 7560 0.1736 16. 60 810.00 0.0186 18 . 30 3105 0. 0713 20.00 5400 0.1240 21 . 70 7695 0.1767 16.70 945.00 0.0217 18.40 3240 0.0744 20. 10 5535 0.1271 21. BO 7830 0 .1798 16.80 1080 0.0248 18.50 3375 0.0775 20. 20 5670 0.1302 21.90 7965 0.1829 16. 90 1215 0.0279 18.60 3510 0.0606 20.30 5805 0.1333 22.00 8100 0.1860 17 .00 1350 0.0310 18. 70 3645 0.0837 20.40 5940 0.1364 22.10 8235 0.1890 17 .10 1485 0.0341 1.8.80 3780 0.0868 20.50 6075 0.1395 22 .20 8370 0.1921. 17.20 1620 0. 03 72 1.8. 90 3915 0.0899 20 .60 6210 0.1426 22 .30 8505 0.1.952 17.30 1755 0.0403 19 .00 4050 0.0930 20.70 6345 0.1457 22.40 8640 0.1.5183 17.40 1890 0.0434 19.10 4185 0.0961 20.80 6480 0.1488 22.50 8775 0.2014 1.7.50 2025 0.0465 19.20 4320 0.0992 20. 90 6615 0.1.5151 1.7. 60 2160 0.0496 19 .30 4455 0.1023 21. 00 6750 0.1550 4 4/26/01 12:48:44 am DETENTION VAULT CALCS FILE No. 7976-VLT Shareware Release PSEA&TP page --------------------------------------------------------------------- STAGE STORAGE TABLE RECTANGULAR VAULT ID No. 2 Description: VAULT (W/ 30%) Length: 98.00 ft. Width: 18.00 ft. voids: 1. 000 STAGE <----STORAGE----> STAGE <----STORAGE----> STAGB <----STORAGE----> STAGE <----STORAGE----> (ft) ---cf-----Ac-Ft-(ft) ---cf-----Ac-Ft-(ft} ---cf-----Ac-Ft-(ft) ---cf-----Ac-Ft- ======================================================================================================~~ 16.00 0.0000 0.0000 17.20 2117 0.0486 18.40 4234 0. 0972 19. 60 6350 O.l.458 16.10 176 .40 0.0040 17.30 2293 0.0526 18.50 4410 0.1012 19. 70 6527 0.1498 16.20 352. 80 0.0061 17 .40 24?0 0. 0567 18.60 4586 0.1053 19. 80 6703 0, 153 9 16.30 529.20 0.0121 17.50 2646 0.0607 18.70 4763 0 .1093 19.90 6880 0.1579 16.40 705. 60 0.0162 17.60 2622 0.0648 18.80 4939 0 .1134 20 .OD 7056 0.1620 16.50 882.00 0.0202 17.70 25199 0.0688 18.90 5116 0 .1174 20.10 7232 0.1660 16.60 1058 0. 0243 17 80 3175 0.0729 19 00 5292 0.1215 20 20 7409 0.1701 16.70 1235 0.0283 17. 90 3352 0.0769 19. 10 5468 0.1255 20 . 30 7565 0 .·1741 16.80 1411 0. 0324 18.00 3528 0.0810 19 20 5645 0. 12 96 20.40 7762 0.1782 16. 90 1588 0. 0364 18 .10 3704 0.0850 19.30 5821 0 .1336 20.50 7938 0 .1822 17.00 1764 0.0405 18. 20 3881 0. 0891 19.40 5998 0 .1)77 17.10 1940 0.0445 18. 30 4057 0.0931 19.50 6174 0.1417 5 4/26/01 12:48:44 am DETENTION VAULT CALCS FILE No. 7976-VLT Shareware Release PSEA&TP page --------------------------------------------------------------------- STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No. Description: VAULT STANDPIPE Outlet Elev: 16.00 Elev: 14.00 ft Elev: 18.80 ft STAGE <--DISCHARGE---> STAGE (ft) ---cfs---------(ft} Orifice Orifice 2 <--DISCHARGE---> ---cfs--------- 1 Diameter: Diameter: 2.0771 2.4785 STAGE <--DISCHARGE---> (ft) ---cfa--------- in. in. STAGE (ft) 1..'lq," 1..'/1:' <--DISCHARGE---> ---cfs--------- ======================================================================================================== 16-00 0.0000 17.20 ~-l.283 18 .40 0.1814 19.60 0 .3713 16.10 0.0370 17,30 0.1335 18. so 0.1851 19 70 0.3834 16 20 0.0524 17.40 0.1385 18.60 0.1888 19 80 0.3949 16 30 0.0641 17. so 0 .1434 18.70 0 .1924 19.90 0.4061 16.40 0.0741 17 .60 0.1481 18. 80 0,1959 20.00 0.4168 16.50 0.0828 17.70 0 .1527 18.90 o. 2521 20.l.0 D.4271 16 .60 0.0907 17 80 0.1571 19. 00 0. 2773 20.20 0. 4372 16.70 0.0980 17. 90 0 .1614 19 .10 0.2975 20. 30 0.4470 16. 80 0 .1047 18 00 0.1656 19. 20 0.3149 20.40 0.4565 16.90 0 .1111 18 .10 0.1697 19. 30 0.3306 20.50 0.4657 17.00 0 .1171 18.20 0.1737 19.40 0. 3450 17 ,10 0.1228 18 .30 0.1776 19.50 0. 3585 6 4/26/01 12:48:44 am DETENTION VAULT CALCS FILE No. 7976-VLT Shareware Release PSEA&TP page ---===========---------------==================-------=============== STAGE DISCHARGE TABLE RISER DISCHARGE ID No. 2 Description: lOOYR RISER OVERFLOW CHECK Riser Diameter (in}: 15.00 Weir Coefficient ... : 9.739 Orif Coefficient ... : 3.782 elev: height: increm: 20.00 ft 20.50 ft 0.10 ft STAGE <--DISCHARGE---> STAGE <--DISCHARGE---> STAGE <--DISCHARGE'---> STAGE <--DISCHARGE---> (ft) ---cfe---------{ft) ---cfs---------(ft) ---cfs---------(ft) ---cfs--------- 20.00 0.0000 20.10 0.3850 20.30 2.0004 20.50 4.3041 20.00 0.0000 20.20 1.0889 20.40 3.0797 7 4/26/01 12:48:46 am DETENTION VAULT CALCS FILE No. 7976-VLT Shareware Release PSEA&TP page ----=====-===---===----==----====--===----====--===---=====--======== LEVEL POOL TABLE SUMMARY MATCH INFUlW -STO--DIS-<-PEAK·> <--------DESCRIPTION---------> {cfa} (cfa) --id---id-<-STAGE> id 2YR ROUTED lOYR ROOTED 2YR FINAL .. lOYR FINAL ..•.. lOOYR Q.F. CHECK 0.19 0,42 0.19 0.42 0.00 0.94 1.43 D. 94 l. 43 1.97 1 1 2 2 2 1 2 18. 73 8 20.00 9 18.29 10 19 3 9 11 20 30 12 OUTFLOW STORAGE {cfs) VOL (cf) o.19 3681.15 cf o.42 5405.69 cf 0.18 4043.17 cf 0.34 5975.18 cf 1.97 7580.84 cf 9 I 1' {__ e V Ii I , I I i i i I i i "' "' -f ~~a (J I \ \ ____ _::, /' }) ') / / I / I/ ! / L./ / / i ! "' • ~ ... ; / ' \ \ \ > I i---- ~ """'-' "''""' ,-;:-----.. __ I I \ \ -')~ / <F''"'"'s- !--- - D I i i i j : 7JJ' ! "" l H I.\J: \I! I. / r I!", 1·,if ~ A!PHAi.T J F,\\ID,t[NT /) , I' lJ I ' ti--•' --r-"'' --=i-~ . . 7-~-~-1 'l=f====u o:JIC_ . / \ i / '----. ~S.--"'l·V~f <'',_'<I\;~.;, ., , .,. f}/1,,,l'}' --~~-... ---,, ,,,,,,. ~ '-:::._git:)/~:,,~\ --. ' I -0-""' -=-----------\ I\ ~!7~0.,1,__q It ~iii~~ I \i;ll,'Oi · '< ',UC~H'· 1i'1~_M••1:i.g \ le!!" (i!E)-1~:t ';[lt' (S) •'1!s:.s' • ' U.S. DEPARTMENT OF AGRICULTURE SOIL CONSERVATION SERVICE Wo 2~ R. 4 E. R. 5 E . .--:.:. 't'oil' So ~ • Tu • ~ ~ I SOIL CO:'SlRVAllON S(RVIC[ \ SOIL LEGEND Ti.,. f;,-., cop;r0 1 1.,.,.,, ;, ,h.,, ;,.,;,..,I.,.,...., oi rh.e ,o;I """"' A u:co.-..:1 co::,,cl 1,. .. ,.,. A, B. C. D. E:, <>< F. ;nd,ca,.,, ,t>.e clo,s of slO\X". Symbols _;,t,ou< o sl.;,:c 1 .. ,..,, o•e rl-.o~e of ,...,ody 1.,.,...,1 ,od, SYMBOL A98 -.c AgD "' •~• A...C A• s.c 8<0 ... Bh e, "" (1, Eo Ed E,B E.C C.D E..C ••• lnC In() ... N<C ... Nk No Pc "" Pv Py HAME Al.de,---ood gro..-,elly sandy loo ... , 0 lo 6 pcr.::<::nl ,lop<::s Ald..-,-ood 9<ovc,lly ,o.ondy loam, 6 to l.S p<N"ce-nt slopc-:1; Al~ooJ 9<0 ... e-rly soncfy loa .... JS to 30 pc«:..,m· slope-:1; Al-de,---ood ond Kilsop so;!,:, "'ffy stc...,,p Ar-e-nts, Akkrwood onotc,tiol,0 lo 6 pc,«:;e-nr slopes.• Ati!nts., Ald., ..... oo,;J ..-.::tlfffol, 6 lo IS pe,rcc,nl sl""'f'""'s • Arenls., f ... ....-.,11 ,r,olefiol • ·Beovsile g,o ... .,Uy sQn(fy loam, 6 lo 15 ll)C:f<"nl slopes S.:0...SII"' gro-lly sondy loo"', 15 10 30 PffCC-tu slopes · e~-.i. ... 9' ....... ,~ .. "'=---..<!,· k::""', ~ •= :r~ ;:.-...-~.:..,, d::...--,~ e..·llinghom stl, loo"' S,-iscot sH, 1-... Bve_Ucy ,.;I, loom foo-'-:,nr silt e-... Edg,-•d• ,._, sondy loo.,. fv,r,.,tf 9f"O...clly ~y loom, 0 lo S pe,t.::"nf slopes [__,-cit ~lfy S9f:ldy loo•,. S IO 15 pHC,e,nl slc:,pes f..-,,,...'l!U Sf"O.....,lly sondy loo"', IS,.,. JQ p,e.-c-enl sl~s f......,,..c-N-Aldc""'vod' ~lly sondy loo<n$, !:, to IS .....-.::e-nt 5loi,u lt-od+ono&o '-r '"'-' soncl, Oto4 p,c-rce:nt .. lope:-s t,,,J.-.o&o ,_...,. f;n. sond • .C to IS pc-,-ctm slope-,- 1nd'oonolo ._..,.. fine sond, IS to JO ,...n::ent sSop..s K>fsop sih ~. 210 8 perce,w slope-s Kitsop sih 1--. 8 to JS pef"Cent slopes Ki,_p sih loo., 15 tq JO petcenf slopes Klovs ~lly IOOflt)" sond. 6 to 15 pncflU ,slopes N.e,ihon --,.vv-lly !oon,y ,sond, 2 to IS PffCe-nt -s~s Newbff-g sih loon, Noobo,clo: sih to.,., N..-""O sondy f-oo,.. Orcos pcot Ood.o sih 1- 0-U g,«1..-lly tootR. Oro 15 pncenr slope1- 0..0II 9"l""""lly loo"", 1S to 2S PffCenl s~s 0-11 go'VYtlty i-... -40 to 15. p,c-tctf"II -slope-1, Pikhud, Joo...,. (j...., sond Pilc:h,..clt f....., son6,<..S- Puge-1 silt)' cloy loo"' Puy,ollup ,,_ -..-dy lo,g.,. Ro( R09ftoo-f;"" 1--0ndy IOOffl, 6 10 IS p,c-rce-n1 slope-s RoO R09..oo-fine: w,...dy Jo,g.,., lS to 25 ,.......cc-n1 sic:,pe-s RdC Rognoo--lndiootolo assocOQ1io,1. sk,ping • RdE Rog._-.tMionqlo ossociori .... "'Ode-.. oiely ue•p • Re Renton slh toe,.,. Rh Rt ... e,,_s.._ So Solol sib loc- Sh S--.,.;;sh sill~ si. S..--..ntc -.,.,1,, S,.. 9-.okOf _.1, s,. s• s a, loci.., !,a ~i5h ,_;h la:1m Sr ~ish 1,h 1-.... th.iclt •urfoc"° .,..,..;o .. , Su Svho" s;h l,:,c:- Tv Tvl.-,lo .-..-cc. ~\\'o • 11..-CO-pos•••~oi 0 ""f1.4" ''""'> ,1. n~"4" ,..~,;,;,t,1., ,...,,, •ho• ,•I 11><· ;., ,he-o, .. o. ~ .... ;, 1,c~ ~ ....... ,-..... ,cu .. c-,-11 , .• ,.-..,;ii-.,, ......... ""~',.,.·-- .. ~,-·( •,nJ ,.1-,r "'' ,1-w-,.:,!1- KING COUNJY AREA. v. , .. , 4:,,. ' ., S-, •• ~ .... ·-··· ':,...•c••• i'--.-.. ~ ...... ·---•t- ,.,..:. "l ... ,,, .,, KING COUNTY, WASHINGTON, SURFACE WATER DES I G N MAN UAL 121 CN values can be area weighted when they apply to pervious areas of similar CN's (within 20 CN points). However, high CN areas should not be combined with low CN areas (unless the low CN areas are less than 15% of the subbasin). In this case, separate hydrographs should be generated and summed to form one hydrograph. FIGURE 3.5.2A HYDROLOGIC SOIL GROUP OF THE SOILS IN KING COUNTY SOIL GROUP HYDROLOGIC GROUP* SOIL GROUP HYDROLOGIC GROUP* f--------·-------1-----------+------------+---------I Alderwood Arents, Alderwood Material Arents, Everett Material Beausite Bellingham Briscot Buckley Coastal Beaches Eartmont Silt Loam Edgewick Everett Indianola Kitsap Klaus Mixed AlllNial Land Neilton Newberg Nooksack Normal Sandy Loam C C B C D D D Variable D C A/B A C C Variable A B C D Orcas Peat Oridia Ovall Pilchuck Puget Puyallup Ragnar Renton Riverwash Salal -Sammamish Seanle Shacar Si Sill Snohomish Sultan Tukwila Urban -~Woodinville HYDROLOGIC SOIL GROUP CLASSIFICATIONS D D C C D B B D VariabJe C D D D C D C D -Variable 0- A. (Low runoff potential). So,ls having high infiltration rates, even when thoroughly wetted, and consisting chiefly of deep, well-to-excessively drained sands or gravels. These soils have a high rate of water transmission. B. C. D. • (Moderately low runcff potential). Soils having moderate infiltration rates when thOroughly wetted, and consisting chiefly of moderately fine to moderately coarse textures. These soils have a moderate rate of water transmission. (Moderately high runoff potentiai). Soils having slow infiltration rates when thoroughly wetted, and consisting chiefly of sons with a layer that impedes downward movement of water, or soils with moderately fine to fine textures. These soUs have a slow rate of water transmission. · (High runoff potential). Soils having very slow infiltration rates when thoroughly wened and consisting chiefly of clay soils with a high swelling potential, soils with a permanent high water table, soils with a hardpan or clay layer at or near the surface. and shallow soils over nearly impervious material. These soils _have a very slow rate of water transmission. From SGS, TR-55, Second Edition, June 1986, Exhibit A-1. Revisions made from SCS, SoD Interpretation Record, Form #5, September 1988. 3.5.2-2 11/92 KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL TAilLE 3.5.2ll SCS WESTERN WAS HIN GT ON RUNOFF CURVE NUMBERS ------~-------=-='-'-====---·-------- SCS WESTERN WASHINGTON RUNOFF CURVE NUMBERS (Published by SCS in 1982) Runoff curve numbers for selected agricultural. suburban and urban land use Jor Type 1A rainfall distribution. 24-hour storm duration. ·-· CURVE NUMBERS BY HYDROLOGIC SOIL GROUP LAND USE DESCRIPTION A B C D Cultivated land(l ): winter condition 86 91 94 95 Mountain open areas: low growing brush and grasslands 74 82 89 92 Meadow or pasture: 65 78 85 89 Wood or forest land: undisturbed or older second growth . 42 64 76 81 Vilood or forest land: young second grmvth or brush 55 72 ~, 00 Orchard: with cover crop 81 88 lc/2 94 Open spaces. lawns, parks, goJf courses, cemeteries, landscaping. good condition: grass cover on 75% @] or more of the area 68 80 86 fair condition: grass cover on 50% to 75% of the area 77 85 90 92 Gravel roads and parking lots 76 85 89 91 Dirt roads and parking lots 72 82 87 89 Impervious surfaces, pavement, roofs, etc. 98 98 98 12§..l Open water bodies: lakes. wetlands, ponds, etc. 100 100 100 100 Single Famiy Residential (2) Dwelling Unit/Gross Acre % Impervious (3) 1.0 DU/GA 15 Separate curve number 1.5 DU/GA 20 shall be selected 2.0 DU/GA 25 for pervious and 2.5 DU/GA 30 impervious portion .. 3.0 DU/GA 34 of the site or basin 3.5 DU/GA 38 4.0 DU/GA 42 4.5 DU/GA 46 5.0 DU/GA 48 s.s·DU/GA 50 6.0 DU/GA 52 6.5 DU/GA 54 7.0 DU/GA 56 Planned unit developments, % impervious condominiums, apartments, must be computed commercial business and industrial areas. (1) For a more detailed descr1pt1on of agricultural land use curve numbers refer to National Eng,neenng Handbook, Section 4, Hydrology. Chapter 9, August 1972. (2) Assumes roof and driveway runoH is directed into street/storm system. (3) The remaining pervious areas (lawn) are considered to be in good condition for these curve numbers. 3.5.2-3 11/92 K I N G C O U N T Y, W A S H I N G T O N, S U R F A C E W A T E R D E S I G N M A N U A L FIGURE 3.5.lC 2-YEAR 24-HOUR ISOPLUVIALS ·' I .' ,. \-·-·---!. .\ .\ l1--- 7.~ ...... ./ l~ 1.i ll;J lf! / / ~'--'--cv 2-YEAR 24-HOUR PRECIPITATION .-3.4 -ISOPLUVIALS OF 2•YEAR 24-HOUR TOTAL PRECIPITATION IN INCHES 0 1 2 3 4 5 6 7 8 Mll.s 1: 300,000 3.5.1-8 1/90 \\ I , ; '"':; K I N G C O U N T Y, W A S H I N G T O N. S U R F A C E W A T E R D E S I G N M A N U A L FIGURE 3.5.IE 10-YEAR 24-HOUR ISOPLUVIALS ---- 2.T 22 <3 \ \ 10-YEAR 24-HOUR PRECIPITATION 3.4-ISOPLUVIALS OF 10'YEA8 24-HOUR TOTAL PRECIPITATION IN INCHES 0 1 2 3 4 5 6 7 6 MIios 1: 300,000 ( K I N G C O U N T Y, W A S H I N G T O N, S U R F A C E W A T E R ·o E S I G N M A N U A L G, \ •-YEAR 24-HOUR PRECIPITATION ISOPLUVIALS OF 25-YEAR 24-HOUR TOTAL PRECIPITATION IN INCHES 0 1 Z 3 .C 5 6 7 8 Mll*I 1: 300,000 3.5.1-11 ' ' .... 1/90 K I N G C O U N T Y, W A S H I N G T O N, S U R F A C E W A T E R D E S I G N M A N U A L FIGURE 3.5.IH 100-YEAR 24-IIOUR ISO PLUVIALS 6 \ JO-YEAR 24-HOUR PRECIPITATION -ISOPLUVIALS OF 100-YEAR 24-HOUR TOTAL PRECIPITATION IN INCHES 0 l 2 3 4 5 6 7 8 Miles .l: 300,000 3.5.1-13 ~ It O· 1/90 ~l~~ \NE,TVlrtJLT 4/26/01 1:0:20 pm DETENTION VAULT CALCS FILE No. 7976-VLT Shareware PSEA&TP BASIN SUMMARY BASIN ID: Cl SBUH METHODOLOGY NAME: 64% 2YR POST-DEV (WETVAULT) TOTAL AREA ....... : RAINFALL TYPE .... : PRECIPITATION .... : TIME INTERVAL .... : 2.21 Acres KC24HR 0.67 inches 10.00 min BASEFLOWS: AREA .. : CN .... : TC .... : o.oo cfs PERV 0.42 Acres 90.00 8.81 min ABSTRACTION COEFF: 0.20 PEAK RATE: 0.23 cfs VOL: 0.08 Ac-ft TIME: 480 min page 1 IMP 1.79 Acres 98.00 8.81 min 4/26/01 1:0:20 pm DETENTION VAULT CALCS FILE No. 7976-VLT Shareware Release PSEA&TP page 2 -------------------------------=================================-==-- HYD NUM 2 3 4 5 PEAK RUNOFF RATE cfs TIME OF PEAK min. HYDROGRAPH SUMMARY VOLUME OF HYDRO cf\AcFt Contrib Area Acres ----7 0.228 480 3287 cf 9 10 cf 2.21 2.21 2.21 • fjtJD ffG 1 D \JlJL,\Ylv'\£.. ~ VSU\l~: -ffo~c 11,U>\J. NZfA <t~ ttiftN l A<-· -No (l.-omJ\ ~ t,10~ -IN C.(2€.AS£_ ~fl:ol... \JtiLl.Jl\A..£, BY [.<; 1D ~ foie-. ~ BtD'i.~ . -?1 2-81 y; \.'?"" 4-,4~.':0 CF ~·D _ \lCiLOME. ~~ cc 0,Z..42. l.F ~ • 'ti NJ:) SofJ-ffr:l.£.. M'iA OF ~"'I·, ~ 'D .: l t. o~ I IMf\J ~~ -:. "11,412. "'IC \ ·; • ~ '1fp £-F ~t::li):)-= <=t~' ")C l '8 ' '::> l 1 loll.-SF ~ I - V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN Enclosed are typical calculations necessary for sizing of the pipe facilities proposed on this project. The rational method and Mannings formula were used for sizing purposes. Conveyance pipes have been sized to accommodate the 100-year storm event at the flowing full condition. The intent of the pipe system within the parking lot is to convey stormwater runoff into the detention vault. The proposed vault has not been sized to accommodate any off-site development. 7976.003 [DED/mmlkn] JOB NAME: JOB#: 7976 REVISED: 3115101 A= Contributing Area (Ac) C= Runoff Coefficient Tc= Time of Coneentration (min) 11;1 Intensity at Tc (In/hr) d• Diameter of Pipe (In) L• Length of Pipe (ft) D• Water Depth at Qd (in) FROM TO A s 797 BARGHAUSEN CONSULTING ENGINEERS· PIPE FLOW CALCULATOR using the Rational Method & Manning Formula KING COUNTY DESIGN FOR 100 YEAR STORM NOTE: ENTER DEFAULTS AND STORM DATA BEFORE BEGINNING DEFAULTS I C• 0.851 n= 0.012 I Qd= Design Flow (els) Qt,.: Full Capacity Flow (efs) Vd .. Velocity at Design Flow (fps) Vfo Velocity at Full Flow (fps) s• Slope of pipe (%) n• Manning Roughness Coefficient Tt= Travel Time at Vd (min) L d Tc n 0 d• 12 Tc-10 COEFFICIENTS FOR THE RATIONAL METHOD "l~·EOUATION STORM Ar Br 2YR 1.58 0.58 10YR 2.44 0.64 PREOIP= 3.9 25YR 2.66 0.65 Ar= 2.61 50YR 2,75 0.65 Br= 0,63 100YR 2.61 0.63 SUMA A"C SUMA"O I Qd Qt Qd/Qf ====cs ••==== =1;1•1;1== =====m c:aaea ••••-=====•= ====== •m==== ====== ====•• ••===o::=s """"""=== ::acasm =====::i:: :•ua===== 086 C85 0.47 0.62 97 12 10.0 0.012 0.85 0.47 0.40 0.40 2.39 0.95 3.04 0,314 085 082 0.56 0.62 200 12 10.5 0.012 0.85 1.03 0.48 0.88 2.32 2.03 3.04 0.668 0134 082 0.37 1.00 97 12 10.0 0.012 0.85 0.37 0.31 0.31 2.39 0.75 3.86 0.196 083 082 0.34 1.00 85 12 10.0 0.012 0.85 0.34 0.29 0.29 2.39 0.69 3.86 0.179 082 CB1 0,48 2.39 66 12 11.3 0.012 0.85 0.48 0.41 1.89 2.21 4,17 5.96 0.700 081 VAULT 0.00 2.39 26 12 11.4 0.012 0.85 0.48 0.00 1.89 2.20 4.14 5.96 0,696 VAULT EX60" 0.00 0.50 40 15 11.5 0.012 0.85 0 0.00 1.89 2.19 4.13 4.95 0.836 :ge 1 Did D Vf Vd I Tt •••••• ====== ====== ==•==• 0.383 4.60 3.87 3.42 0.47 0.597 7.17 3.87 4.14 0.81 0.296 3.55 4.92 3.78 0.43 0.283 3.40 4.92 3.71 0.38 0.617 7.40 7.60 8.23 0.13 0.613 7.36 7.60 8.21 0.05 0.697 10.46 4.03 4.51 0.15 / I I i ! ! i i 20· "' ,<,SPHALT PA\a,IO,IT I J ii L, i ! I I i \ ! ,7·- "' "' ( I I~ ,_ '> \ \ ' ,/.'; A~A<.l pAR;!(•',C, VI. SPECIAL REPORTS AND STUDIES VI. SPECIAL REPORTS AND STUDIES Miscellaneous reports and letters have been included for review. 7976.003 [DED/mmlkn] VII. BASIN AND COMMUNITY PLAN AREAS VII. BASIN AND COMMUNITY PLAN AREAS The project is located within the Green River Drainage Basin. The community plan area is called "Green River Valley." 7976.003 [DED/mmlknl I I, ~ I / ilJ I ,·! I' '/I ,1JI I I, I ! ll --11' 111 j' ~./1 'J _/_ .. ,..,: 11 I L,. 7, ,J;. 10 ,, 'I L ,,. .,,- -·_--;:"·~-·, I: C ~ si !'-;; l, ;J I 'I If I. I \ l 'l 11 1 .. I I I ,' .·· ,·' L • i l ; u. ., I I I I I I I I ! i ~ ... .. ~ • .., " ~ 0 .• ,, ' ., . '·'" ' .Ip j) > 'jl\ JJ··· l, j, < :I'. ·~ '•. i' .,.,. ; .' 0 j -v; j( \ . /1"····· " .-· \; ' . " i, _, ,.,,., .. , ·~· ... ,: ,' ~. \ JI' .,. ; : , .. JJ . ~\ I ' ' ' " ' ,, I· ,; ' l G ,, a: w > ... ... ' -( I a: l ' ,,1, , ... ~ul '~~."-,;I" . ,• :::> a.. /.' '·.'; .r' ... '· ii ' JJ' I' ' ' l H l/1 .''1i ' N i r.i; .. ?r·; j ., ~.! ··.y '··· ..... en z -t/J c( m ?: e w sill C, l!'-c( i2 z -~ C ' 1.,>j··_' :; > ~J> ,,,,. -· .. ..... Ji' !, i::' ca ~ "O ca C "O ::, C s ::, s I: 'iii C &l I ... 0 ..0 'iii' ::, ~ (J) I • • e < l: -~ ~ ·'a.! ; g; .,, ?:~ § 11 8 .. l!'E ;; .2· .. o 3 ... "i ~~ .. •If' . /FI f' I~ jf . ( ,,,/ \. , . '} ,;;·-' ·,, ... . .I 'f.., .~1 \ ..1· ( ··'to- ,•' ., ... '\ > I: I· ' i \' f f j .. ~ ~ ~ • "' N 0 , I / I ;1 i :• ' 1 ' 0 0 0 6 0 "' ~ t· ' \ \ \ .I 1 vm. OTHER PERMITS VIII. OTHER PERMITS At this time. the pennits anticipated for this project are as follows: • Roadway and Drainage Construction • Grading Pennit 7976.003 [DED/mm/kn] IX. EROSION/SEDIMENTATION CONTROL DESIGN IX. EROSION/SEDIMENTATION CONTROL DESIGN '!be limits of clearing have been shown on the construction plans to encompass the entire site area. Silt fences have been shown on the plans to protect the adjacent properties from any possible sediment runoff. Since the site is only approximately 2 acres in size, and currently infiltrates all on-site storrnwater, we do not feel that it is necessary to provide any form of sediment traps or ponds. As construction progresses, silt fences will be maintained, and catch basin protection will be installed to ensure that all storrnwater leaving the site is clean and free of sediment. Once the underground detention vault is installed, it will act as a sediment trap, which will ensure that not sediment laden water will leave the site. 7976.003 [DED/mmlkn] X. ADDITIONAL DOCUMENTS X. ADDITIONAL DOCUMENTS A. RETENTION/DETENTION FACILITY SUMMARY SHEETS AND SKETCHES 7976.003 [DED/mmlkn] K I NG C O U NT Y, WAS H _I N GT O N, S U R FA C E WATER D ES I G N MA N U A L RETENTION/DETENTION SUMMARY SHEET Development f'UC,'i.:r ~ £L£cnzt£AL APP(2€,sTJC£5!-hP Date ::> / 1s / b I NJb~rJJ;.fb f12-llv.eAw'i Location S. ll-.l, l nf ~ ::r:H:fMA.s -P<-!5:-~~~ _____________ _ ENGINEER Name H*L ./,(2.uB'B · DEVELOPER 12-, Name l2t U-1~ "'-' Sf.t2- Firm "BAf'-f,tft\:UYiN Address l '62..1'5 72 ,-rt, /l(vf., S k'."f..NI ~ "l&o'3z.. Firm "Fli"1f[ Slltr~fJ UU·f(ZJCl\1....-/'if'ff20:Sr1t£S!IP Address 07Vo 60 M, S. $0 J'TL-Zoo S£1<7Ilk.. IPA '18JO~ Phone 4?-0 -'2$1 -i,Z:z.z__ Phone 'Zolo -1b3 -'71S<:, • Developed Site Z. 2.. acres Number of Lots - • Number of Detention Facilities On Stte -~I __ _ • Detention provided in regional tacilfty D Regional Facility location ---------------~---- • No detention required D Acceptable receiving waters • Downstream Drainage Basins Immediate Basin A ---------- Basin B ---------- Basin C ---------- BasinD _________ _ TOTAL I Drainage Basin(s) 'l. • 'Z-I OnstteArea -Off site Area \/l>(VL--r Type of Storage Facility Live Storage Volume I., r'i~D Predeveloped Runoff Rate 2year 10 year Postdeveloped Runoff Rate 10o·year 2year 10year DevelopedO 100year Type of Restriction Size of Orifice/Restriction Orifice/Restriction No.1 No.2 No.3 No.4 No.5 Major Basin Gl?f0:-? 12:W ve.- INDIVIDUAL BASIN A B C -z :z.' --C . V/1<\Jt.f' l?,'l~ . D. lob D. '5£}1 (7.91i 0,'lll'J' l. St"! 2.114- ~~ct.. z 1/i " -:, ·1~· D . XI. MAINTENANCE AND OPERATIONS MANUAL K I NC CO U NT Y, \\' ,\ S 11 I N (, T () N, S U i( F 1\ C E \VAT E !( D F S I G N M A N U A L MAINTENANCE REQUIREMENTS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO. 1 • PONDS Maintenance Component General Side Slopes of Pond Storage lvea Emergency Overllow/Spillway ------------- Dtlfecl Trash & Debris Poisonous Veg&lalion Pollution Unmowed Grass/ Ground Cover Rodent Holes Insects Tree Growth Erosion Sediment Rock Missing Conditions When Maintenance I• Neitci&d My trash and debris which exCEted 1 cubic foot per 1C()() square feet (this is about equal lo the amount ol trash it would take lo lill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Any poisonous veg elation which may conslilule a hazard lo County personnel or tho public. Examples of poisonous vegetation include: tansy ragwort, poison oak, stinging nettles, devils club. Oil, gasoline. or other contaminanls of one gallon o, more .Q! any amount round thal coukl: 1) cause damage to plant, animal, o, marine life; 2) constitute a fire haz8rd; or 3} be flushed downslream during _rain storms. H facility is located in ptivate residential area. mowing is needed when grass exceeds 18 inches in height tn other areas, the general poHC)' is lo mi.ke the pond site malch adjacent ground cover and terrain as long as there 1s no interference with the function of the facility. Any evidence of rodent holes if facility is -acting as a dam °' betm, or any evidence of water piping through dam or berm via rodent holes. 'Nhen insects such as wasps and homets interfern with maintenance activities. T tee growth does not allow maintenance access or interferes with maintenance activity {i.e., slope mowing, silt removal, vactoring ot equipment movements). tf treH are not interfering with access, leave treH atone. Eroded damage over 2 inches deep whate cause of damage is still present or where there is potential for continued erosion. Accumulaled sediment that exceeds 10% of the designed pond depth. f':~y pJ~ :' ~:-__ ' '-:.:'.: '.'" ,:: : ... :::..;-,j ~ inches lower 1han the design elevation. Only one layer of rock exists above native soil in area live square feet o, larger. or any exposure ol native soil. .-... -1 --------- Reaults Expected Vo/hen Maintenance Is. Performed Trash and debris cleared Imm site. No danger of poisonous vegetation where County personnel or the public might normally be. (Coordination with Seattle/King County Health Department) No contaminants present other than a surface film. (Coordination wilh Seattle/t<Jng County Health Departmenl) When mowing Is needed, gtass/ground cover should be mowed to 2 inches In height. Rodents destroyed and dam or berm repaired. (Coordination with Seattle/ King County Health Department) Insects destroyed or remo~ed from site. Trees do not hinder maintenance activities. Selectively ct.iltivate trees such as alders for fitewood. Slopes should be stabilized by using appropriale erosion control measure(s): e.Q-. rock reinforcement, planting of grass, compaction. Sediment cleaned out to designed pond shape and depth; pond reseeded if necessary 1o contml erosion. ;:;.;;.,o :,.,...,.,;l,l Utt Ou1h oack to mu oc~1~u elevation. Replace rocks to design standards. i/.1<.; K l N (j C O U N T \' 11· ,\ S H N (; T O N, S U R F /\ C E W /\ T l, 1, D L ~ I (, N M ,\ N U /\ L NO. 2 -INFILTRATION Malntonenca Component GenMal Sto,age Alea Filter Bags Rock FlUe,s Trash & Deb,is Poisonous Vegetation Pollution Unmowed Grass/ Ground Cove, Rodeol Holes Ins.sets Sediment f"eet Cover (tt Applicable) Sump Filled With Sediment and Debris (H Applicable) Filled with Sediment and Deb!iS Sediment and Debris CondltJona 'Nhon Maintenance la N&oo&O See ·Ponds.· Standard No 1 See ·ponds· Standard No. See ·Ponds· Standard No. &te "Ponds· Standard No. See ·Ponds· Standard No. 1 A pe,,oolation test pit or test of facility indicates facility is only working at 90% o1 its designed capabilities. Sheet cover Is visible and has more than lhcee 1/4--inch holes in it. Any sediment and debris filling vault to 10% of depth from sump bottom to bottom of outlet pipe o, obstructing flow into the connector pipe. Sediment and debris fill bag more than 1/2 full. By visual Inspection littJe or no water flows through filter during heavy rain storms. A-7 Rc•ulta f..xp,K-tcd 'When Maintenance la Performed ·--· ----------------- Sae "Ponds S1anda1d No 1 Soe "Ponds S1anda1d No See "Ponds Standard No. See "Ponds S1andard No See "Ponds S1anda'rd No. 1 See "Ponds S1anda1d No. 1 &.diment is removed and/or facility is cleaned so that infiltration system works according to design. Sheet cover repaired or replaced. Clean out sump to design depth. Replae& filter bag or redesign system. Replace g,avel in rock tilter. 1/90 K I N G CO U N T Y, \I' A S H I N G TO N, S lJ R r A C L W A T E R D E S I G N M A N l' A L NO. 3 CLOSED DETENTION SYSTEMS (PIPES/TANKS) Maintenance Cornponent Storage Alea Manhole Catch Basins D<tloct P1ugged Air Vents Debris and Sediment Joints Between Tank/Pipe Section Tank/Pipe Bent Out of Shape Cover not in Place Locking Mechanism Not Working Cove, Difficult to Remove Ladder Rungs Unsafe Conditions When Maintenance Is Needed One-hall ol the cross s.eclion ol a vent is blocked at any point wilh debcis and sediment. Accumulated sediment depth exceeds 10% of the diameter ol the slorage area for 1/2 length of storage vault o, any point depth exceeds 15% of diame1er Example: 72-inch storage tank would require cleaning when s.ediment 1eaches depth. of 7 inches for more than 1/2 length of tank. My ctack allowing material 1o be transported into facility. Any part of tank/pipe is bent out of shape more than 10.% of its design shape. Cover is missing or only partially in place, Ally open manhole requires maintenance. Mechanism cannot be opened by one maintenance pe,son with proper tools. Bolts into frame have less than 1 /2 inch of thread (may not apply to sell-locking lids). One maintenance person cannot remove lid after applying 80 pounds of lift. Intent is 10 keep cover from sealing off acoess to maintenance. · King County Safety Offioe and/or maintenance person judges that ladder is unsafe due to mls.sJng rungs. mlsallgnment, rust. or ccacks. See ·eatch Basins· Standard No. 5 i\-J Rcuulb Expectod When Maintenance Is Performed Vanis ltae ol debris and sedimenl All sedimenl and debris removed from slorage area. AJI joints between tank/pipe sections are seated. Tank/pipe 1epaired or replaced to design. Manhole is closed, Mechanism op.,ns with proper tools. Cover can bo removed and reinstalled by one maintena!lce person. Ladder meets design standards and atrows maintenance persons safe access. See ·eatch Basins· Standard No. 5 I iW K I N G CO U NT Y, W A S H l N G T O N, S U R F A C E W A T E R D E S I G N M A N U A L ----· ------- NO. 4 · CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Component ~feet Conditions Whi&n M.alntenance Is Needed Results bp<t<;ted ',','hen Maintenance ls Performed ···------------.---------------------- Goner al Cleanout Gato Orifice Plate CNerflow Pipe Manhole Catch Basin Trash and Deb£is (includes Sedimonl) Structu1al Damage Damaged or Missing Damaged 01 Mis.sing Obstructions Obstructions Dislanca between debris build-up and bottom of orifice plate is less than 1-1/2 feet. · Structure is not s.ecurely attached to manhole wall and outlet pipe structure should support at least 1,COO pounds ot up or down pres.sure. Structure is not in upright position (allow up to 10%. from plumb}. Connections to outlel pipe are not watertight and show signs of rust. Any holes -other than designed holes - in the struciuro. Oeanout gale is not watertight or is missing. Gate cannot b6 moved up and down by one maiiltenanoe person. Chain leading to gate is missing or damaged. Gate 1,. rusted over 50% of its surface area. Control devi~ Is not working properly due to missing. o~t of plaoe, or bent orifice plate. My trash. debri,.. sediment. or vegetation blocking the plate. My trash °' debris blocking {0< having the potential of blocking) the overflow pipe. Soe "Cloud Detention Systems· Standard No.3. See ·Catch Basins• Standud No. 5. .AJI 1rasti and debris remo,.,ed. Structure securely attached lo wall and oullet pipe. Strue1ure in corre~t position. Connections to outlet pipe are watertighl; structure repaired Of replaced and works as designed. Structure has no holu other than designed holes. Gate is watertight and wori<s as designed. Gate moves up and down easily and is watertight. Chain is in place and works as designed. Gate is repaired oc replaced lo meet design standards. Plate is In place and works l!S designed. Plate is free of an obstructions and works as designed. Pipe is heo of all obstructions and works as designed. See paosed Detention Systems.· Slanda,d No.3. See ·Catch Basins• Standard No. 5. 1 /()0 KI NG C CJ li NT Y. \VAS HING TON, SUR r-ACE \\'ATER DES I G N MANUAL NO. 5 CATCH BASINS Mlllntenance Componcmt Gene,al Defect Trash & Dobris (Includes Sed1menl) Structural Damage to frame and/or Top Slab Clacks in Basin Walts/Bottom Settlement/ Misalignment Fire Hazard Vegetation Pollution Conditions Whon Maintenance la Needed Trash or deb1is of more than 1/2 cubic ·foot which is located immediately in Iron\ or lhe catch basin opening o, is blocking capacity ol basin by more lhan 10% Trash or debris (in the .basin) that exceeds 1/3 the depth horn the bottom ol basin to invert of the lowest pip·;-·- Of out ol lhe basin. Trash or debris in any inlet or outlet pipe blocking more than 1 /3 ol ils height. Dead animals or vegetation that could generate odOfs that would cause complaints or dangerous gases. (e.g .. methane). Deposits of garbage, exceeding 1 cubic foot in volume. Corner of frame extends more than 3/4 inch past"curb race·into the street [if applicable). Top slab has holes larger than 2 square inches Of ciacks wider than 1/4 inch Qntent is to make sure all material is running into the bas.in). Frame not sitting flush on top slab, i.e .• separation of more than 3/4 inch of the frame from the top slab. C,acks wider 1han 1 /2 inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that structure is unsound. Cracks wider than 1 /2 inch and longer than 1 fool at the joint of any inletfoutlet pipe °' any evidence of soil particles entering catch basin through cracks. Basin has settled more than 1 inch or has rotated more than 2 inches out of align(nent. Presence of chemicals such as natural gas, oil. and gasoline. Vegetation ·growing across and blod:ing 010<0 than 10% of the basin opening. Vegetation growing in inlet/outlet pipe joints: lhat is more than six inches tall and loss u1c11 ::., .... 111..:nes. apart. Nonflammable chemicals of more than 1 /2 cubic fool per th1ee feet of basin leng1h. Result& Expected When Maintenance I.a Performed No 1rash or debtis located immediately in lront ol ca\ch basin opening. No trash 01 debris in the catch t;>asin. Inlet and outlet pipes free of trash or debris. No dead animals or vegetation p,esent within the catch basin. No condition present which would att,act 01 support the breeding of insects or rodents. frame is even with curb. Top slab Is free of h~les and aaeks. Frame is sitting 11ush on top slab. Basin replaced or repaired to design standards. No cracks mote than 1 /4 inch wide at the joint of !nletfoutlet pipe. Basin replaced or repaired to design standards. No flammable chemicals present. No vegetation blocking opening to basin. No vegetation or rool growth present. No pollution present other than surtace lilm. 1/90 K I N G C U U N T Y, \\' A S H I N C T O N, S U R FA C E W A I E R l) ES I G N M A N U A L NO. 5 -CATCH BASINS (Continued) Malntonancc Componont Condition• \Vhen Malnt,on.once la Naod•d Reoulh. Expo<:lod Vr'hen Malntonanco la Porform(ld ------·------"------- Catch Oasin Cover ladder Metal Grates ~r applicable) Cover Not in Place Locking Mechanism Not Working Cover 0.t1icult ·') Remove Ladder Rungs Unsafe Trash and Debris Damaged or Missing Cover is missing or only partially in place My open ~tch basin requires maintenance. M-echanism cannot ba opened by one maintonanco person wilh proper tools. Bolts into frame have less than 1 /2 inch ol thread. · One maintenance person cannot remove lid after applying BO Jb.s~ ol lift; intent is keep co ... e, ffom sealing off access to maintenance. Ladder Is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Grata with opening wider than 7 /8 inch. Trash and debris lhat is blocking more than 20% of grate surface. Grate missing or broken member(s) of the grate. !\ r:. Catch basin cover is closed Mechanism opans with proper tools. Covar can be rem9ved by one maintenance persOn. Ladder meets design standards and allows maintenance person sa.fe access. Grate openings meet design standards. Grate free of trash and debris. Grate is in place and meets design standards. 1/Q(l K I N C CO LI NT Y. IV AS 1-l I NG TO N, S \J R FACE IV ATER D ES I G N MA NU A L NO. 6 -DEBRIS BARRIERS (e.g. Trash Racks) Malnt~nance Cornpon(ln\ General Metal [}(, f ocl T,ash and Deb1is. Damaged/ Missing Bars Condt-tlona \Vhen Malntcnnnce h No-&ded .T,ash Of dobris lhat is plugging more than 20% of the openings in the bar1ier. Bars are bent out of shape more than 3 inche-s. Bars are missing or entire barrier is missing. Bars arc looso and rust is causing 50% dete,io,ation to any part of barrier. A-7 A<1 •uth Exp«:tc-d 'Nhen Maln1enanco Is Performed Barrier clear to receive capacity flow_ Bars. In plaet1 with no bends more than 3/4 inch. Bars in place according lo design. Repair-or replace barrier 10 design standards. i/';JU K I N G C O U N T Y, WA S II I N G TO N, S U R .-1\ C E W ,\ T L R D [ S I c; N M A N U A L NO. l -ENERGY DISSIPATORS Me.lnt<"Jnl'lnce Component Rock Pad Dispersion Trench Internal: Manhole/Chamber [Mfoct Missing or Moved Rock Pipe Plugged with Sediment Not Discharging Wate, Properly Perforalions Plugged Waler PJWs OJI Top oi ·Distributor· C'.atch Basin Receiving Alea Oler-Saturated Worn or Damaged-- Posts, Baffles. Sides of Chamber Other Defects Condition• WlHH\ Malntennnce la Needctd Only one 18.yer of rock exisls above native soil in area five square fEtet or larger, or any exposure of nalive soil. Accumulated sedim&nt that exC&eds 20% of the design depth Visual evidence ol water discharging et concentrated points along trench (normal condition is a ·sheet floW of waler along trench). Intent is to prevent erosion damage. Over 1 /2 of perforntions in pipe are plugged with debris alld sediment. Maintenance person observes water flowing out during any st0<m less than ths design storm or it Is causing or appears likely to cause damage. Water in receiving area is causing or has potential of causing landslide problems. Structure dissipating tlow deleriorates to 1/2 or original size or any ronoentcated worn spot exceeding one square foot which would make structure unsound. See ·eatch Basins· Standard No. 5 .,, . 0: Re1ut1a Exp«ted When Mzdntonanc~ h Pedormod fl.eplac.e rocks to design standard Pi~ deaned/flushed so lhal ii matches design. Trench must be tedasigned or rebuilt to standard. ~ Clean or replace pertorated pipe. Facility must be rebuilt or redesigned to slandatds. No danger of landslides. Replace structure to design standards. S&e "Catch Basins· Standard No. 5 1/90 f; I N c; CO UN T Y, WAS 1-l I N GT ON, S U R r 1\ C E W ,\TE R DES I G N M A NU A L NO. 8 -FENCING Maintenance Component General Wire Fences Missing or Broken Palis Erosion Damaged P.1H1s Dete,iorated Paint °' Protective Coating Openings in Fabric Condition• \Vhen Malntonance I• Need&d My defect in the fence lhat pormils easy -entry lo a facility. Paf'ls broken or missing. Erosion mou!I than 4 inches high and 1 2~ 18 inches wide permitting an opening under e fonca. Posts out of plumb moro than 6 inches. Top rails bent more than 6 inches. My part of fence (Including posts, top rails, and fabric) more than 1 foot oul of design alignment. Missing or loos.e tension wire. Missing 0< loose barbed wire that is sagging more than 2-1/2 inches between posts. Extension arm missing, broken, or bent out of shape more than 1-1 /2 inches. Part or parts that have a rusting or scaling condition that has affected structural adequacy. Openings in fabric are such that an a,. inch-diameter ball could fit through. 1\.·':.J Re,ult• Expected \'/hen Malntentmce le Performed Parts in place to provide adequate security. &oken or missing par13 teplaced. No opening under the fence thal exceeds 4 inches in height. Posts plumb to wilhin 1-1/2 inches. Top rail lrne ot bends greater than 1 inch. Fence is aligned and meets design standards. Tension wire in place and holding fabric_ Batbed wire in place with less than 3/4- inch sag between posts. Extension arm in ptace with no bends lai'ger than 3/4 inch. Sttucturally adequate posts or parts with a uniform protective coating. No openinQs in fabric. 1, ·,, ,.,- KING C Cl UN TY. IV AS II ING TON, SURFACE IV ATER DES I G N ~I AN U A 1. NO .. 9 -GATES Malnlenaoce Component Genoral Damaged o, Missing Members Openings In Fabric -"---·~ ---------~ Condition• W'hen Maintenance la Ne+<lo-d Mis.sing gate or locking devices Btoken o, missing hinges such lhat gato canno1 be easily opened and closed by a maintenance person. Gate is out o1 plumb more than 6 inches and more than t foot out of design alignment. Missing stretche, bar, stretcher bands, and ties. See 'Fencing· Standard No. 8 Reaulh E:xp-o-ch,d Vlhen M.alnlenanc111 Is Potlotmed Gates and locking devices in plaC-8_ Hinges intact and lubed. Gate is wo,king freely. Gale is aligned and vertical. Stretcher bar, band~. and ties in place. See "F~ncing· Standard No, 8 K I N G C O U N T Y, WA S H I N GT O N, S U R FA C E W A T E R D E S I G N M A N U A L ------------------------------·· NO. 10 -CONVEYANCE SYSTEMS (Pipes & Ditches) M.!!lntenAnce Componenl Pip6S Open Ditches Catch Basins Debris Barciers (e.g., Trash Rack) Def&ct &ldiment &. Debris Vegetalion Damaged Tcash &. Debris Sediment V&gotation Erosion Damage to ·slopes Rock Lining Out of P1ace or Missing {H ftpplicable) Condition• When Maintenance la Needed Accumulated sedimonl that exe<Jeds 20% ot lhe diameter of the pipe. Vegetation that reduces free mov<1ment of wa16r through pipes. Proteciive coaling is damaged; rust is causin~ more than 50% delerioralion 10 any part of pipe. Any dent that decreases the cross section area of pipe by mar~ than 20'%. Trash and debris exceeds t cubic foot per .1.000 square feet of dilch and slopes. Accumulated sediment that exceeds -20% ~f the design depth. Vegetation 'that reduces freo movement of water through ditches. See ~Ponds· Standard No. 1 Maintenance person can see native-soil beneath the rock lining. S&e "Catch Basins· Standard No. 5 See ·oe:bris Barriers· Standard No. 6 A-11 Reaulta E.xpil'Cl&-d \.Vhen Mtilntenance l:s Performed Pip-e cletl.ned of all sediment and debris. AJI vegeta1ion removed so waler flows lreety th10ugh pipes. Pipe repaired o, replaced. PipG repaired or replaced. Trash and debris cleared from ditches. Ditch cleaned/flushed of all sediment and debfiS s.o lhat it matches design. Water flows freely through ditches. Seo ·Ponds· Standard No. 1 ReplaC6 rocks lo do sign standard. See ·Catch Basins" Standard No. 5 See ·Debris Barriers· Standard No. 6 J,90 KI NG CO U NT Y, WASH I NG TON, SUR FACE WAT ER D ES I G N MA N U A L NO. 11 -GROUNDS (Landscaping} \1alntonance Component General T,ees and Shrubs Weeds (Nonpoisonous) Sarety Ha2.a1d Trash or Litter Damage Condition• When Malntonanco I• NH<l&d Weeds growing in more than 20% ol the landscaped area (trees and shrubs only). Any presence of poigon Ivy or olher poisonous vegetalion. Paper, can, bottles, lolalling more than 1 cubic toot within l!I landscap~d area (trees and shrubs only} of 1,0CIO squarf:I feel. Limbs or parts of \fees or shrubs thal are split or broken which affect more than 25% of tho total foliage of the tree or shrub. Trees or shrubs Ulat have been blown down or knocked over. Trees or shrubs which are nol adequalely supported or are loaning over, causing exposure of the roots. ... J...'. ------------------- A", u tta E.x p-3-Cte-d \.'lhen Maintenance Is Performod Weeds present in less than ~% of lhe lends.caped area. No poisonous vegetalion pie sent in a landscaped area. Alea clee, of litter. Trees and shrubs with less than 5% of the total foliage with split or broken limbs. Tree or shrub in place flee of injury. Treo or shrub in place and adequatety supported; remove any dead or diseased trees . KING COUNTY, WASHINGTON, SURFACE WATER DES I G N MANUAL -------~-------- NO. 12 -ACCESS ROADS/EASEMENTS Maintenance Componont General Road Surface Shouldets and Ditches Defect T1ash and Debris Blocked Roadway Sottlement, Potholes, Mush Spots, Ruts Vegetation ln Road Surface Erosion Damage Woods and &ush Condition& \l.'hen Malnt,onance la Heeded Trash and debris e)(ceeds 1 cubic loot per UXX) square feet, i.e .. trash and debris would fill up one standard size garbage can. Debris which could damage vehicle tires (glass or metal) Ally obstructions which reduce clearance above road surface to less than 14 feet. Any obstructions restricting the access lo a 10-lo 12.foot width for a distance of mo,e t_han 12 feet or any point restricting access to less than a 10-foot width. W'hen any surface defect exceeds 6 Inches in depth and 6 square feet in area. In gonoral, any surface defect which hinders or prevents maintenance access. Weeds g1owing in the road surface that are more than 6 inches iall and le~ than 6 Inches apart wilhin a 400--square-foot area. Erosion within l--foot of the roadWay more than 8 inches wida and 6 inches deep. Weeds and brush exooed 18 inches. In height or hinder maintenance access. A-13 Re~ult~ Ex~1e-d 'When Malnlenance Is Perlormed Trash and debtis cleared from site. Roadway free of debris which could damage tires. Roadw~y overhead clear 10 1 "I feet high. Obstruction removed to allow at least a 12-foot access. Road surface uniformly smooth with no evidence of settlemenl. potholes, mush spots. or ruts. Road surface free of weeds taller than 2 inches. ShoUlder fre8 of erosion and matching the s·orrounding road. Weeds and brush cut to 2 fnches in height or cleared in such a way as to allow maintenance ac:cess. 1/90 Geotechnical Engineering Design Study Harper Engineering Building Renton, Washington Prepared for Harper Engineering July 18, 2007 7508-02 -.. --------------- 11/JRTCRoWSER .. .. HIJRTCRoWSER Geotechnical Engineering Design Study Harper Engineering Building Renton, Washington Prepared for Harper Engineering July 18, 2007 7508-02 I EXPIRES 03-12-0 j I I J. Jeffrey Wagner, PE Principal, Geotechnical Engineer I 910 Fairview Avenue East Seattle, Washington 98102-3699 Fax 206.328.5581 Tel 206.324.9530 CONTENTS Page INTRODUCTION 1 PURPOSE AND SCOPE OF WORK 1 PROJECT UNDERSTANDING 2 The Site 2 The Proposed Building 2 SUBSURFACE CONDITIONS 2 Site Soils 3 Groundwater 4 GEOTECHNICAL ENGINEERING CONCLUSIONS AND RECOMMENDATIONS 4 General Considerations 4 Site Preparation 5 Structural Fill 6 Settlement Monitoring Program 7 Building Foundations 8 Floor Slab Design 11 Seismic Considerations 11 Drainage Considerations 12 Temporary Excavations 13 RECOMMENDATIONS FOR ADDITIONAL GEOTECHNICAL SERVICES 14 USE OF THIS REPORT 1 s FIGURES Vicinity Map 2 Site and Exploration Plan 3 Settlement Plate Installation Detail Hart Crowser Page i 7508-02 July 18, 2007 CONTENTS (Continued) APPENDIX A FIELD EXPLORATIONS METHODS AND ANALYSIS Explorations and Their Location The Use of Auger Borings Standard Penetration Test (SPT) Procedures Previous Explorations FIGURES A-1 Key to Exploration Logs A-2 Boring Log HC-1 A-3 Boring Log HC-2 A-4 Boring Log HC-3 A-5 Test Pit Log TP-1 and TP-2 A-6 Test Pit Log TP-3 and TP-4 A-7 Test Pit Log TP-5 APPENDIX B LABORATORY TESTING PROGRAM Soil Classification Water Content Determinations Atterberg Limits (AL) Grain Size Analysis FIGURES B-1 Unified Soil Classification (USC) System B-2 Liquid and Plastic Limits Test Report B-3 Particle Size Distribution Test Report Hart Crowser 7508-02 July 18, 2007 A-1 A-1 A-1 A-2 A-2 B-1 B-1 B-1 B-1 B-2 Page ii GEOTECHNICAL ENGINEERING DESIGN STUDY HARPER ENGINEERING BUILDING RENTON, WASHINGTON INTRODUCTION This report presents the findings and recommendations of our geotechnical engineering design study for the proposed Harper Engineering Building to be located at 770 SW 7th Street in Renton, Washington. We have organized this report into several distinct sections as follows: • Introduction; • Purpose and Scope of Work; • Project Understanding; • Subsurface Conditions; • Geotechnical Engineering Conclusions and Recommendations; • Recommendations for Additional Geotechnical Services; and • Use of This Report. Figures follow the main text. Figure 1 is a Vicinity Map. Figure 2 is a Site and Exploration Plan that shows the proposed structure and the locations of our explorations. Figure 3 presents construction details for proposed settlement plates. These are followed by appendices addressing field explorations (Appendix A) and laboratory tests (Appendix B). PURPOSE AND SCOPE OF WORK Hart Crowser 7501>-02 July 18, 2007 The purpose of our work is to provide Harper Engineering and their design consultants with geotechnical engineering recommendations related to the design and construction of the proposed facility. Our scope of work for this project included the following: • Reviewing subsurface information from previous explorations by Hart Crowser; • Advancing three borings to a maximum depth of 71 feet; • Performing laboratory tests including visual classifications, Atterberg limits, and grain size analyses; • Performing geotechnical engineering analyses; and • Preparing this report. Page 1 PROJECT UNDERSTANDING The Site Figure 1 is a Vicinity Map that shows the location of the site, located at 770 SW 7th Street in Renton, Washington. It is approximately triangular in shape, with leg dimensions of about 450 and 250 feet, and covers an area just over 2 acres. It currently is an asphalt-paved parking lot. The site is relatively flat. The Proposed Building Figure 2 is a Site and Exploration Plan that illustrates the layout of the proposed structure. We understand that current plans call for a 20,000-square-foot light manufacturing building with a portion of the structure used as an office. The building footprint will be about 210 feet in a north-south direction and about 85 feet in an east-west direction. The structure will be situated in the eastern portion of the triangular site. The remainder of the site will remain as an asphalt- paved parking lot. We understand that the new building will be a one-to two-story slab-on-grade structure with the finished floor elevation very near the existing parking and street level. No significant grade changes or excavations are planned. We understand that foundation loads will be relatively light and typical for a building of this size. Perimeter wall loads will be on the order of 1,500 pounds per linear foot. Maximum interior column loads will be about 95 kips. Floor loads will be relatively light, less than 100 pounds per square foot. For seismic considerations, based on our conversations with the structural engineer, the building has a fundamental period of 0.2 second and the building will be designed per IBC 2006 design criteria. The site surrounding the proposed building will remain as an asphalt-paved parking lot. No grading or modifications to the asphalt surface are planned. We understand that there are no settlement-sensitive structures or utilities within 20 feet horizontally of the proposed building footprints. We understand that any existing storm lines within this area will be removed as part of construction. SUBSURFACE CONDITIONS Hart Crowser 7508-02 July 18, 2007 Our understanding of the subsurface conditions at the site is based on materials encountered in explorations conducted by Hart Crowser for the current study Page 2 Site Soils Hart Crowser 7508-02 July 18, 2007 and on our review of existing exploration logs (test pits) prepared by Hart Crowser for previous site work in 2000 (Project No. 7508 dated December 18, 2000). Our explorations for the current study consisted of three borings. The locations of these subsurface explorations are presented on Figure 2, Site and Exploration Plan. Subsurface soil conditions interpreted from the explorations formed the basis for developing the conclusions and recommendations contained within this report. The nature and extent of variations between explorations may not become evident until construction. If variations then appear evident, it will be necessary to re-evaluate the recommendations of this report. Details of conditions observed in the explorations are presented in Appendix A and should be referred to for more specific information. In general, the upper portion of the site, beneath the parking lot pavement and subgrade section, is underlain by very soft Silt and Clay that contain variable amounts of fine sand. These soft compressible soils generally extend to a depth of about 7 to 17 feet. Beneath this highly compressible zone, we encountered loose to medium dense Sand with varying amounts of gravel. Generally, this Sand becomes medium dense at a depth of 13 to 24 feet and then dense at a depth of about 25 to 35 feet. At a depth of about 64 feet, we encountered hard, sandy Silt. A more detailed description of subsurface soil types is as follows: • Compressible, Very Soft Silt and Clay. This is the prevalent soil type in the upper portion of the site. Laboratory tests indicated these soils to be of low plasticity. These soils will generally govern the design of the preload/ surcharge and the shallow footing foundations. • Sand. The upper portions of the Sand were generally in a loose condition and contained only trace amounts of organic material. With depth, the Sand becomes increasingly more dense and gravelly. The Sand is relatively much less compressible than the overlying Silt and Clay. • Hard Silt. Our deep boring, at a depth of about 64 feet, encountered and terminated in hard, sandy Silt with ash pumice. This layer is not expected to be a factor in the design of shallow foundations, but would provide very good support of deep foundations if they become necessary. Page 3 Groundwater It is important to note that as we reviewed the field samples in our laboratory, we noted that several of the gravelly sand samples from borings HC-1 and HC-3 (at depths of about 17.5 to 25 feet) exhibited a petroleum-like odor. Screening tests performed in the "head space" of the plastic sample jars in our laboratory indicated the presence of volatile organic compounds. We did not sample or preserve these samples with the intent of performing environmental laboratory tests, so these test results should not be relied upon for environmental purposes. We recommend that this condition be investigated further. Additionally, we noted a sheen on the groundwater within the split-spoon sampler at depths of about 15 to 30 feet in borings HC-1 and HC-3. We encountered groundwater in each of our three borings at a depth of about 10.5 to 11.5 feet below the ground surface. These groundwater observations are representative of the conditions at the time of the field explorations. Fluctuations in groundwater may occur as a result of variations in rainfall, temperature, season, and other factors. Previous test pits encountered groundwater as shallow as 8 feet below grade. Also, the amount of groundwater that seeps into a boring or excavation depends on the length of time that the boring or excavation remains open as well as the material in the boring or excavation sidewalls. The color of many of the soils samples in the upper portions of the borings has been described as "mottled," which is an indicator of a fluctuating groundwater level. GEOTECHNICAL ENGINEERING CONCLUSIONS AND RECOMMENDATIONS This section of the report presents our conclusions and recommendations regarding the geotechnical aspects of design and construction. We have developed our recommendations based on our current understanding of the project. If the nature or location of the building is different than we have assumed, Hart Crowser should be notified so we can change or confirm our recommendations. General Considerations Hart Crowser 7508-02 July 18, 2007 One predominant characteristic of the site with respect to geotechnical issues is the upper unit of very soft, compressible Silt and Clay that underlies the area. This will affect earthwork techniques, site preparation, and selection of the foundation type for the proposed structures. During construction, the site soils will provide poor support for earthwork equipment if they are exposed in a wet Page 4 or disturbed condition. After construction, loads from fills and structures applied at the ground surface will cause consolidation of these soils, resulting in surface settlements. As such, these soils will generally drive construction procedures as well as the geotechnical design. Another predominant characteristic of the site is the potential liquefaction of site soils at depth due to a design seismic event. It is likely that these soils will liquefy and cause settlement of the ground surface and building footings. Provided that the owner is prepared to accept significant building and floor settlements resulting from soil liquefaction, building loads may be supported by shallow footings. However, this approach will also require: • Site preloading; and • Overexcavation of compressible soils and placement of structural fill beneath footings. Site Preparation Hart Crowser 7508-02 July 18, 2007 In preparation for construction, we recommend the following for site preparation in the building area: • Break up the existing pavement in the proposed building area in preparation for subsequent surcharge preload/placement. The lateral extent of the pavement demolition should extend 10 feet beyond the perimeter of the new building footprint; • Place preload/surcharge fill as described herein; • Remove preload/surcharge fill and asphalt pavement; • Beneath footings, overexcavate a minimum 4 feet beneath building footings and replace with 4 feet of compacted structural fill (refer to the Structural Fill section); and • If large areas of the original ground surface or the exposed subgrades beneath footings are unusually soft or disturbed, use of a geotextile stabilization fabric beneath the fill layer or a greater thickness of fill may be necessary to achieve a stable working surface. Groundwater was encountered in our explorations at depths of about 8 to 11.5 feet. Groundwater elevations may fluctuate. Therefore, the contractor should be prepared to deal with groundwater during site preparation, excavations, and Page 5 Structural Fill Hart Crowser 7508-02 July 1 e. 2007 foundation installation. We recommend that ditching and sumping first be used to control groundwater. Other methods of groundwater control may be required during construction. Selection, Placement, and Compaction Criteria For imported soil to be used as Structural Fill, ideally, we recommend using a clean, well graded sand or sand and gravel with less than 5 percent by weight passing the No. 200 mesh sieve (based on the minus 3/4-inch fraction). Compaction of material containing more than about 5 percent fine material may be difficult if the material is wet or becomes wet during rainy weather. We recommend the following regarding placement and compaction of the fill: • Prior to placement of the preload/surcharge fill, prepare the site as previously recommended herein; • Proof roll the ground surface with a heavy static roller prior to placing fill; • Place fill in maximum 12-inch loose lifts; • Compact the preload/surcharge fill to at least 90 percent of the maximum dry density as determined by the modified Proctor test method (ASTM D 1557); and • After removal of the preload/surcharge fill, compact structural fill beneath footings and slabs on grade to at least 95 percent of the maximum dry density as determined by the modified Proctor test method (ASTM D 1557). Use of On-Site Soils as Structural Fill The suitability of excavated site soils for compacted structural fill will depend on the gradation and moisture content of the soil when it is placed. As the amount of fines (that portion passing the No. 200 sieve) increases, the soil becomes increasingly sensitive to small changes in moisture content and adequate compaction becomes more difficult to achieve. Soil containing more than about 5 percent fines cannot be consistently compacted to a dense non-yielding condition when the water content is greater than about 2 percent above or below optimum. Reusable soil must also be free of organic and other deleterious material. Page 6 In general, our explorations indicated that the on-site soils consist of fine-grained silt and clay with varying amount of organic material. We recommend against using this material for structural fill. It may be possible to use this material in landscaped areas that will not be required to support pavements and that do not require compaction. It would be very difficult to achieve even minimal compaction or work with this material if it is wet when it is excavated or if it becomes wet during construction. PreloadfSurcharge Fill Height In the building areas, place fill to an elevation 6.5 feet above the top of the proposed building floor slab. In these areas, the top of the surcharge fill should extend outside the building perimeter a distance of 10 feet and slope downward at an angle of 1.SH:1 V or flatter. Duration of PreloadlSurcharge The appropriate duration that the preload and surcharge fills should remain in place is difficult to accurately predict. Based on our experience with preloads in the project area, we anticipate that the duration for the preload may be on the order of 3 months. It is very important that the preload/surcharge fill settlement be monitored carefully as recommended herein. Settlement Monitoring Program Hart Crowser 7508-02 July 18. 2007 For the settlement monitoring program, we recommend the following: • Install settlement plates at strategic locations in the building and pavement areas. We recommend that at least eight settlement plates be evenly distributed across the building area. • Install settlement plates as shown in the typical installation detail (Figure 3). • Monitor settlement with conventional survey techniques. The settlement plates should be installed after preparing the subgrade and prior to placing any fill. • A surveyor should obtain initial settlement plate elevations immediately after placement of the plates and prior to placement of any fill. Obtain readings by standard differential leveling to the nearest 0.01 foot. The surveyors must establish a benchmark that will be outside the area of settlement influence; a Page 7 minimum distance of 100 feet is sufficiently far from the project site to obtain reliable survey readings. • During the first two weeks, obtain readings three times per week. After the first two weeks, the frequency may be reduced to twice per week. After four weeks, the frequency may be reduced further; to once per week, but modifying the frequency of the readings may be done only upon the recommendation of the geotechnical engineer reviewing the survey data. • Hart Crowser should review the settlement plate data on a regular basis as they are obtained. This will allow us to make recommendations regarding surcharge duration. Building Foundations Hart Crowser 7508-02 July 18, 2007 General Considerations and Design Approach Existing near-surface site soils generally consist of highly compressible, very soft Silt and Clay. As such, they are not suitable for direct support of building foundations and slabs-on-grade. Under static loading conditions, it is feasible to support the structures on shallow footings and slabs-on-grade provided that a minimum thickness of granular structural fill is placed beneath the footings and slab, above the underlying natural soils. If footings were placed directly on the soft, natural soils, there is a potential for a bearing capacity failure of the shallow footings. In addition to being highly compressible, the natural site soils are also prone to liquefaction and loss of strength during a design seismic event. As such, if the structures are supported on shallow footings, the buildings must be able to tolerate considerable settlement and damage during a seismic event without risk to the occupants, and the owner must be willing to accept significant damage to the structures that may make the facilities unusable until extensive repairs could be made. If such settlements are not acceptable, the alternative is to support the structures on piles that would extend to a considerable depth. Through previous discussions with the architect, we understand that supporting the structure on shallow footings and a slab-on-grade is the desired approach to be addressed by this report. The following paragraphs present our geotechnical design recommendations based on this approach. Page 8 Hart Crowser 7508-02 July 18, 2007 If the owner desires another approach that will perform differently during the design seismic event, we can address deep pile foundations, which is beyond the scope of our current study. The foundation design recommendations contained herein regarding static settlement assume that the surcharge material to be placed over the proposed building footprints will be allowed to remain in place until the underlying soft, compressible material achieves at least 90 percent consolidation. We recommend that Hart Crowser be retained to review settlement survey data. Removal of the surcharge load prior to 90 percent consolidation may cause excessive continued settlement of the subgrade, resulting in potential hazard for the proposed structures. Shallow Foundation Design Foundation support may be provided using shallow pad or continuous footings bearing on the minimum thickness of imported structural fill placed directly above the existing natural soils. We recommend the following: • Found shallow footings on a minimum 4-foot thickness of imported structural fill. • The minimum lateral extent of the fill material should be defined by a plane extending outward and downward from the outside edge of the footing to the top of the native soils at an angle no steeper than 1 H:1 V. • Design footings using a maximum allowable bearing pressure of 1,000 pounds per square foot (psf). • Allow an increase in the allowable soil bearing pressure of up to one-third for loads of short duration, such as those caused by wind or seismic forces. • Design individual footings to have a minimum width of 3 feet. • Design continuous footings to have a minimum width of 24 inches. • Place the base of the footings at least 18 inches below the lowest adjacent finished grade for consideration of frost penetration. Page 9 Hart Crowser 7508-02 July 18, 2007 • Found footings outside of an imaginary 1 H:1V plane projected upward from the bottom edge of adjacent footings or utility trenches. • For resistance to lateral loads, use an equivalent fluid density to represent the passive resistance of the soil. For a typical footing poured against the structural fill, use an ultimate passive equivalent fluid density of 400 pounds per cubic foot (pcf). Use a factor of safety of at least 1.5 when calculating soil resistance to lateral loads. • Use an ultimate coefficient of friction to resist sliding equal to 0.40 for footings poured neat against granular structural fill. Use a factor of safety of at least 1.5 when computing resistance to lateral loads. • Retain Hart Crowser to observe and document footing and backfill subgrade conditions during construction, prior to placement of the footings. Foundation Settlement For foundations designed and constructed as described herein, we estimate that the total post-construction settlement of individual and strip footings under static conditions will be less than 1 inch. We estimate that differential settlement between adjacent footings will be about one-half to three-fourths of the total settlement. These foundation settlement estimates assume that careful preparation and protection of the exposed subgrade will occur prior to structural fill and concrete placement. Any loosening of the materials during construction or the presence of loose material beneath footings could result in larger settlements than those estimated herein. It is important that the foundation excavations be cleaned of loose or disturbed soil prior to placing any concrete and that there be no standing water in any foundation excavation. Provided that our preload/surcharge recommendations are followed during construction, long-term settlements due to continued consolidation of the compressible site soils and decomposition of organic material beneath the buildings are expected to be minor and generally fairly consistent across the footprint of the structure. As such, we do not anticipate long-term differential settlement to be an issue. Estimated settlements as a result of a seismic event are discussed subsequently. Page 10 Floor Slab Design The floor slabs may be constructed as slabs-on-grade. We recommend the following: • Design floor slabs to bear on a minimum 18-inch-thick layer of imported structural fill material above the natural soils. • At least the uppermost 6 inches of this structural fill layer should consist of free-draining capillary break material. This free-draining layer should contain less than 3 percent by dry weight passing the No. 200 sieve (based on the minus 3/•-inch fraction of the material). • For design of the floor slab, use a modulus of subgrade reaction of 100 pounds per cubic inch (pci), as measured on a 1-foot-square plate. This assumes that the construction is accomplished as described above. • In finished interior areas, such as the office, provide a vapor barrier beneath the slab. • Retain Hart Crowser to observe and document the exposed slab subgrade prior to slab construction to verify suitable bearing surfaces. We estimate that maximum settlement of the floor slabs, under the expected static loading, will generally be less than 1 inch provided that they are designed and constructed in accordance with our recommendations. In the event of an earthquake, floor slabs are likely to experience settlements similar to the building footings, as discussed subsequently. Seismic Considerations Hart.Crowser 7508-02 July 18, 2007 When cyclic loading occurs during a seismic event, the shaking can increase the pore pressure in loose to medium dense saturated sands or soft to medium stiff silt and cause liquefaction or temporary loss of soil strength. Such conditions are present at the project site. This can lead to bearing capacity failure (if footings bear directly on these soils) and surface settlement. In our opinion, the site soils are susceptible to soil liquefaction. As such, we recommend that footings bear on a minimum thickness of structural fill as discussed above to alleviate the bearing capacity issue as previously addressed. However, widespread settlement across the site is likely and must be considered in the design of the structures. In our opinion, settlement due to liquefaction as Page 11 a result of a seismic event may be on the order of 10 to 15 inches. Given the relatively consistent site conditions, we anticipate that such settlements would be fairly uniform across the length and width of the buildings but could vary because of more localized seismic effects. We understand that the seismic design of the proposed building will be performed in accordance with the 2006 International Building Code (IBC). The basis of design for this code is two-thirds of the hazard associated with an earthquake with 2 percent probability of exceedance in a 50-year window of time, which corresponds to an average return period of 2,475-years. We obtained the seismic hazard from the United States Geologic Survey 2002 National Seismic Hazard Maps for Latitude 47.473 and Longitude -122.22 7. Below, we provide parameters for seismic design in accordance with this code. • Maximum Considered Earthquake Spectral Response Acceleration at Short Periods, S, = 1.428 g; • Maximum Considered Earthquake Spectral Response Acceleration at Short Periods, S, = 0.489 g; and • Site Class F. It is our understanding that the building period is 0.2 second. Because of this, according to the IBC, a site-specific analysis is not required and site class E may be used since this is the site class without regard to liquefaction. Although the site soils pose a risk from seismic-induced settlement, the probability of other seismic hazards at the project site, such as lateral spreading, ground rupture, and landslide, are very low. Drainage Considerations Hart Crowser 7508-02 July 18, 2007 Temporary Drainage during Construction We understand that no large, deep excavations are planned for this project Therefore, general site dewatering is not anticipated to be necessary. Also, we expect that excavations for footing construction will occur above the elevation of the encountered groundwater. As such, we do not expect groundwater control to be a significant issue. However, some control of surface runoff may be necessary during construction. Page 12 Permanent Slab and Footing Drainage We recommend the following: • Install perimeter footing drain around the new structures. The drains should consist of minimum 4-inch-diameter perforated pipe surrounded by at least 6 inches of free-draining material. • Design the foundation drainage system to drain by gravity, sloping downward toward an appropriate discharge, independent of other site drainage systems. • The slabs should be underlain by free-draining material as described above. • At this time, we do not anticipate the need for cross drains beneath the structure given our understanding of the site and our expectation that building grades will be above the groundwater level. However, the need for cross drains should continue to be reviewed and assessed during construction. Temporary Excavations Hart Crowser 7508-02 July 18, 2007 We do not anticipate that construction will require temporary excavations greater than 4 feet deep. We present general guidelines below if such excavations do become necessary. However, if such excavations are needed, Hart Crowser should be notified to address them more specifically. The stability and safety of cut slopes depends on a number of factors, including: • The type and density of the soil; • The presence and amount of any groundwater/seepage; • Depth of cut; • Proximity of the cut to any surcharge loads near the top of the cut, such as stockpiled material, traffic loads, structures, etc. and the magnitude of these surcharges; • Duration of the open excavation; and • Care and methods used by the contractor. We make the following general recommendations for open cuts: • Protect the slope from erosion by using plastic sheeting; Page 13 • Limit the maximum duration of the open excavation to the shortest time period possible; • Place no surcharge loads (equipment, materials, etc.) at the top of the cut within a horizontal distance equal to the depth of the cut; and • Temporary cut slope should be the responsibility of the contractor. For planning purposes, we recommend a temporary cut slope no steeper than 1.SH to 1V. The recommendations presented above are very general in nature. Because of the variables involved, actual slopes required for stability in temporary cut areas can only be estimated prior to construction. We recommend that stability of the temporary slopes used for construction be the responsibility of the contractor, since the contractor is in control of the construction operation and is continuously at the site to observe the nature and condition of the subsurface. All excavations should be made in accordance with all local, state, and federal safety requirements. RECOMMENDATIONS FOR ADDITIONAL GEOTECHNICAL SERVICES Hart Crowser 7508-02 July 18, 2007 Hart Crowser should be consulted during the remainder of the design phase of the project to refine our recommendations as more information about the project requirements becomes available. Before construction begins, we recommend that Hart Crowser be retained to: • Meet periodically with design team as the design plans become more complete. • Review the final foundation design plans (to calculate settlement) and specifications to confirm that the geotechnical engineering recommendations have been properly interpreted and implemented into the design. During the construction phase of the project, we recommend that Hart Crowser be retained to observe the following activities: • Site preparation and placement of structural fill; • Placement of preload/surcharge fill; Page 14 • Assessment of surcharge settlement monitoring data; • Construction of the shallow footing foundations and slabs-on-grades; • Installation of drainage systems; and • Other geotechnical consideration that may arise during the course of construction. The purpose of these observations is to determine compliance with the design concepts, specifications, or recommendations and to allow design changes in the event that subsurface condition differ from those anticipated prior to the start of construction. USE OF THIS REPORT Hart Crowser 7508-02 July 18, 2007 Hart Crowser completed this work in general accordance with our proposal dated June 8, 2007. We performed this work for the exclusive use of Harper Engineering and their design consultants for specific application to this project. We accomplished our work in accordance with generally accepted professional practices in the same or similar localities, related to the nature of the work accomplished, at the time the services were performed. No other warranty, express or implied, is made. J:\Jobs\750802\Harper Geotech Report.doc Page 15 w ! -·-f-· .. .!.~ -·-~-~ 1.iTti .SI_ ·,' I i ~- V) ~. SW qRO_ ST_ 1!i ~ ;:: .... :i '. i S".j33Ril ST ,: I .., :<t.:~.--=-::.~~j_T/1~==-. !==-=tL.: I I ~I .Sl/1larn S1 ! ~ l ~, I 0 1/2 Approximate Scale in Miles 7508-02 -- I RENTON : ! ..J -l 1/,,4;_ .L,'!.\ __ l,~Lrr .. 3~00 i !6 ; CTI/ ···~ff-, ! li/P Harper Engineering Building Renton, Washington Vicinity Map 7107 Figure 111.tRTCROWSER 1 20' p~____) [~~'~ I I ~ t l; ti ~ ~ ~ 0:)2 I.---'" L TP-4 I "·""--...!!. . -D ~ le ~ ..,,,---, .l " -/ I I __ _::-/\ Q<% I re0 \,, \\I ( ;i. \-~ '1 \\ J .-.... > ............ , " ,.,, 1 ~0 ) <Q>""QA I/ ~ ___ .J !'iii T;P~ 'U 00 , , .l . ~llv ""' "1 " ~ C ,// I !i/ --/-----!---------- L __ J "' %, 0 " $ ----22-00 ---- ~~lb~ S HC-02 !'iii TP-1 Boring Location and Number (Current Study) Test Pit Location and Number (Hart Crowser Study, 2000) ' \ 8 {,;" ~ l ,__ ___ :rl' lj '00"19'331_ %5.42' (4§ V-·~ Proposed Building (Approximate) "'~ !'iii t'R,2 ·23.o:,, ____ _ HC-02S Existing Parking Area (to remain) 8 t;i !'iii TP-3 so1·2r10·w 115.02· ~~e ~ ~ ! i oo II ~ :i «< :,; 'u :> ~ °' ' :,:I', ~~ ·g ii.. ·~ ' t I I ol ! I ' o II i I I I t-)J I : 01 [ ________ j ________ ,------·r-------' ' ' I -~! ' § 1.:1 ! I i I • ~. II ;; ~, .... ffi N w \., 0 ll I~ • 0 ~ " ~ ~ ~ . " ~ - I ' I ' I I • ' I ' ~ I 8 ' I Ji~ ' : I I ;J~ :rfi. ' lw I ').;' i5 ii!2 ~~8 l :~;s o<~ " ?:l • --------------\ --a: fti"? "·---... ---... --... --... -... -... - 0 N --,c:_z __ _. 80 7508-02 Harper Engineering Building Renton, Washington Site and Exploration Plan 7107 Figure ~ I o 40 F Source: Base map prepared from electronic file provided by Barghausen Consulting Engineers, dated 05-17--01. . fl l Scale m Feet HIIHIOIOW 1 2 "' I i Additional Pipe and i-._ ' I Coupling as Required ~ _I r' I J / Install Plate and 5' Pipe Riser to this Point before Placing Fill Existing Ground Surfac\ -./ See Detail Below l F==L. ~· L ~n;. _ Concrete Sand l 1 Ci. ' 2' x 2' 1/4" Platej ~ ~ 2" Standard Pipe ~ ~ ~ , ~ Pipe Coupling 7508-02 Harper Engineering Building Renton, Washington Settlement Plate Detail 7107 Figure 3 Hart Crowser 7508-02 July 18, 2007 APPENDIX A FIELD EXPLORATIONS METHODS AND ANALYSIS <C -~ 'tl C: [ 0. <C APPENDIX A FIELD EXPLORATIONS METHODS AND ANALYSIS This appendix documents the processes Hart Crowser used in determining the nature of site soils. The discussion includes information on the following subjects: • Explorations and Their Location; • The Use of Auger Borings; • Standard Penetration Test (SPT) Procedures; and • Previous Explorations. Explorations and Their Location Subsurface explorations for this project included three borings. The exploration logs within this appendix show our interpretation of the drilling, sampling, and testing data. They indicate the depth where the soils change. Note that the change may be gradual. In the field, we classified the samples taken from the explorations according to the methods presented on Figure A-1 -Key to Exploration Logs. This figure also provides a legend explaining the symbols and abbreviations used in the logs. Location of Explorations. Figure 2 shows the location of explorations, located by hand taping or pacing from existing physical features. The ground surface elevations at these locations were interpreted from elevations shown on a site topographic map provided by the project architect. The method used determines the accuracy of the locations and elevations of the explorations. The Use of Auger Borings Hart Crowser 7508-02 July 1 B, 2007 We drilled three hollow-stem auger borings, designated HC-1 through HC-3, to depths ranging from 31.5 to 70.8 feet below ground surface. The borings were completed between June 18 and 19, 2007. The borings used a 4-inch inside diameter hollow-stem auger and were advanced with a truck-mounted drill rig subcontracted by Hart Crowser. A geologist from Hart Crowser continuously observed the drilling. Our geologist prepared detailed field logs of each boring. Using the Standard Penetration Test (SPT), we obtained samples at 2-1 /2-to 5- foot-depth intervals. The borings logs are presented on Figures A-2 through A-4 at the end of this appendix. Page A-1 Standard Penetration Test (SPT) Procedures This test is an approximate measure of soil density and consistency. To be useful, the results must be used with engineering judgment in conjunction with other tests. The SPT (as described in ASTM D 1586) was used to obtain disturbed samples. This test employs a standard 2-inch outside diameter split- spoon sampler. Using a 140-pound hammer, free-falling 30 inches, the sampler is driven into the soil for 18 inches. The number of blows required to drive the sampler the last 12 inches only is the Standard Penetration Resistance. This resistance, or blow count, measures the relative density of granular soils and the consistency of cohesive soils. The blow counts are plotted on the boring logs at their respective sample depths. Soil samples are recovered from the split-barrel sampler, field classified, and placed into watertight jars. They are then taken to Hart Crowser's laboratory for further testing. Previous Explorations Hart Crowser 7508-02 July 18, 2007 Our 2000 study included excavation of five test pits at the project site. We have included copies of the logs of those test pits on Figures A-5 through A-7. J:\jobs\750802\Harper Geotech Report.doc Page A-2 lu !I! 0 > Key to Exploration Logs Sample Description Classification of soils in this report is based on visual field and laboratory observations which include density/consistency, moisture condition, grain size, and plasticity estimates and should not be construed to imply field nor laboratory testing unless presented herein. Visual~manual classification methods of ASTM D 248S were used as an identification guide. Soil descriptions consist of the following: Densilylconsistency, moisture, color, minor constituents, MAJOR CONSTITUENT, additional remarks. Density/Consistency Soil density/consistency in borings is related primarily to the Standard Penetration Resistance. Soil density/consistency in test pits Is estimated based on visual observation and is presented parenthetically on the test pit logs. SAND or GRAVEL Standard SILT or CLAY Standard Ag proximate Penatratlon Penetration S ear Strength Density Reaiatance (N) Conalstenfy Rni.tance (N) In TSF In Blows/Foot In Blows/Foot Very loose 0 IC 4 Very soft O lo 2 <0.125 Loose 4 1010 Soft 2 lo 4 0.125 lo 0.25 Medium dense 10 1030 Medium stiff 4 lo 8 0.25 IO 0.5 Dense 30 lo50 Stiff 8 1015 0.5 to 1.0 Very dense >50 Very stiff 15 to 30 1.0 to 2.0 Hard >30 >2.0 Sampling Test Symbols ~ Splil Spoon E8:l Grab (Jar) [I] Shelby Tube (Pushed) 121 Bag [lil Cuttings D Core Run SOIL CLASSIFICATION CHART MAJOR DIVISIONS SYMBOLS GRAPH LETTER TYPICAL DESCRIPTIONS COARSE GRAINEO SOILS MORE THAN 50% OF MATERIAL IS lNIOEltYIWI NO. ::a SIEVE FINE. GRAINED SOILS MORE. Ttwll !'all. Ol'MATERIAI.IS """"" """ N0.2CKISIE'IE "" GRAVEL AND GRAVELLY SOILS l,IQIQ:T-51N "'"""' .. ''"""" RETAt,eDONNO •6EVE SAND AND SANDY SOILS """'""""' OF COARSE '""""'' PASSINO ON NO .. ..,. SILTS ANO CLAYS SILTS AND ClAYS CLEAN GRAVELS -•I'•' GW . ,vu IUTTl.EORHOFINl:S) { D00 GRAVELS WITH FINE.$ CLEAN SANOS tumE OR NO FINES) SANOS WITH FINES .. .,-, '• .. ··.:,:.::. ···:.: ·.·.··:.• (APPRECIA8l..E r ~ .• 7",;/o' AMOUNT°" FINES) V 7..4 ---- GP GM GC SW SP SM SC OL wa..t..0RADE0 GRAVELS. GRAVEL· SAN0lol)(1VRE5, lITTLE OR NO '"" POORLY-GRADED af!AVELS, Gl'L\VEL ·SNIDM~ES. LITTLE ORHOFNES SLTYGAAVELS, GRAVEL -SANO· ISI.TMIXTI.RE$ CLAYEY GRAVQ.S. 8AAVEL • SMO • CLAYWll\JRES WEU-GRADIED IHI06, GRAVElLY SNfDS, lITTlE OR NO FINES POORLY.oRADED SANDS, GRAVELLY SANO, unu. OR NO '''" S,.. TY So'.NDS, SANO • SILT MIJl:TUIIE& ORGN«: SILTS IHJ OllOJIHC 8lL TY CU.VS OF LOW PlASTICllY I IIIOAaN«MTS,MICACEOUSOR MH ~iv~FINESANODA ua1.11ol1M1T f-C-H-1-'-"°"-"""--"-'"_"_"_'"----< GREATER THAN SO --PLASTICITI' --. OH -. OROANICCLAYSOF liolEDIUMTO HIGH PV,STIOTY. OAGANII; 51.:r.; HIGHLY ORGANIC SOILS PT PEAT, HUMUS, SW1'MP SOllS WITH HGH OR<WaC CONTENTS !ii:! NOTE: DUAL SYtilEIOl.6 ARE \ISEDTOINDCATE BORDERLWE SOllCLASSF!CATIONS . Moisture Dry Little perceptible moisture Damp Some perceptible moisture, likely below optimum Moist Likely near optimum moisture content Wet Much perceptible moisture, likely above optimum Minor Constituents Estimated Percentage Trace <5 Slightly (clayey, silty, etc.) 5 • 12 Clayey, silty, sandy, gravelly 12 -30 Very (clayey, silty, etc.) 30 • 50 Laboratory Test Symbols GS Grain Size Classification CN Consolidation UU Unconsolidated Undrained Triaxial CU Consotidated Undrained Triaxial CD Consolidated Drained Triaxial QU Unconfined Compression OS Direct Shear K Permeabillty PP Pocket Penetrometer Approximate Compressive Strength in TSF TV CBR MD AL PIO CA OT Torvane Approximate Shear Strength in TSF California Bearing Ratio Moisture Density Relationship Atterberg Limits I • I Water Content in Percent I~ Liquid Limit Natural Plastic Limit Photoionization Detector Reading Chemical Analysis In Situ Density in PCF Groundwater Indicators Groundwater Level on Date or (ATD) At Time of Drilling Groundwater Seepage (Tesl Pits) Sample Key Sample Type , Sampe Recovery -'- S-1 IX Sample_} '- Number -.. 12 23 5'('3" \_ Blows per 6-inches IIJJRTCROWSER 7508-02 FlgureA-1 6/07 Boring Log HC-1 Location: See Figure 2. Approximate Ground Surface Elevation: 23 Feet Horizontal Datum Vertical Datum: Drill Equipment: Hollow Stem Auger Hammer Type 140 lb SPT Hole Diameter: inches Logged By: C. Brown Reviewed By: J. Wagner STANDARD PENETRATION RESISTANCE LAB TESTS & (PID) ' USCS Graphic Class Log Soil Descriptions ML Very soft, wet, gray, slightly sandy SILT to clayey SILT t-Very soft, wet, gray CLAY with trace affine sand and organic material. Depth in Feet 0 - _, 5 - - -10 -'1. -~,I -ATD ~-------------------Very soft, wet, gray, sandy SILT. -15 -SM--. .-~--------------------· Medium dense, wet, gray, silty, medium to ' . fine SAND. Petroleum-like odor noted at - 20-foot depth. -20 SW-SM· Medium dense, wet, gray, slightly silty, -·, gravelly to very gravelly SAND. Petroleum-like odor noted at 25-foot depth. - ' 25 ' ' ; '· - ' -30 Sample S-1 S-2 S-3 S-4 S-5 S-6 S-7 S-8* S-9' ' S-10• Bottom of Boring at 31.5 Feet. Started 06/18/07. Completed 06/18/07. - " Sheen observed on groundwater in sampler -35 at sample depths of 20, 25, and 30 feet. -40 1 . Refer to Figure A-1 for explanation of descriptions and symbols. 2. Soil descriptions and stratum lines are interpretive and actual changes may be gradual. 3. uses designations are based on visual manual classification (ASTM D 2488) unless otherwise supported by laboratory testing (ASTM D 2487). 4. Groundwater level, if indicated, is at time of drilling (ATD) or for date specified. Level may vary with time. 0 0 1 0 0 0 0 1 1 0 0 1 0 1 1 1 7 ' 2 6 12 12 13 13 7 9 10 a Blows per Foot 0 10 20 ' .. . • •· • . • • ' . ·• -\ - \ ·\ -\ • ~ • : . --- ---- 0 20 40 30 60 • Water Content in Percent -.. 40 50+ (0.5) -GS :--..(20.3) """(1.4) 80 100+ HIJRTCROWSER 7508-02 FigureA-2 6107 Boring Log HC-2 Location: See Figure 2. Approximate Ground Surface Elevation 23 Feet Horizontal Datum: Vertical Datum: Drill Equipment: Hollow Stem Auger Hammer Type: 140 lb. SPT Hole Diameter: inches Logged By: C. Brown Reviewed By: J. Wagner STANDARD PENETRATION RESISTANCE LAB TESTS uses Graphic Soil Descriptions Depth in Feet Class Log --M-L-~m-v_e_ry_s_o_ft_, _w_e_t_, o_r_a_n_g_e_m_o_tt_le_d_g_r_a_y_, _s_a_n_d_y---o SILT. SP-SM· SP Ii. . ·•· I•>\ > ii 1> -:·.·· · .. ·· : '1-foot-thick, moist, brown, medium to fine SAND layer. f-5 f-10 f- 1-Loose, wet, gray, slightly silty, medium to fine 1- SAND with trace of organic material. 1- >--20 -------------------+ Medium dense, wet, gray, slightly silty, gravelly SAND with wood debris. 1-25 Medium dense to dense, wet, brown to gray, 30 trace to slightly silty, gravelly to very gravelly e SAND . e f- f- >--35 e e r f- ~•o 1. Refer to Figure A-1 for explanation of descriptions and symbols. 2. Soil descriptions and stratum lines are interpretive and actual changes may be gradual. Sample S-1 S-2 S-3 S-4 s-s· s-s· S-7' s-s· S-9 S-10 S-11 3. uses designations are based on visual manual classification (ASTM D 2488) unless otherwise supported by laboratory testing (ASTM D 2487). 4. Groundwater level, if indicated, is at time of drilling (ATD) or for date specified. Level may vary with time. 0 ' ' ' 2 2 0 0 ' 0 0 0 ' 2 3 2 ' 5 5 8 2 ' 0 10 9 12 14 12 12 12 10 15 18 • Blows per Foot 0 10 20 JO ~ • ·• -' fHo • • - -\ .. • -\ - \ • \ - • \ - • } I 0 20 40 60 • Water Contenl in Percent .. .. 7508-02 Figure A-3 40 .• 80 50+ -AL -GS 100+ 6/07 1/2 Boring Log HC-2 Location: See Figure 2. Approximate Ground Surface Elevation: 23 Feet Horizontal Datum: Drill Equipment Hollow Stem Auger Hammer Type 140 lb. SPT Hole Diameter: inches Vertical Datum: Logged By: C. Brown Reviewed By: J. Wagner ~ ~ ~ ~ 0 0 ~ ~ 0 c> ' c> I ,: 0 ~ m s m 0 ~ 0 0 ~ 0 z ~ 0 m ~ w z USCS Graphic Class Log SP Soil Descriptions Medium dense to dense, wet, brown to gray, trace to slightly silty, gravelly to very gravelly SAND. (cont'd) · 'Silty ML Hard, wet, gray-brown, sandy SILT with ash pumice. Bottom of Boring at 70.8 Feet. Started 06118/07. Completed 06119/07. * Samples obtained from supplemental boring drilled -10 feet from HC-2 using mud rotary drill method. 1. Refer to Figure A-1 for explanation of descriptions and symbols. Depth in Feet 40 45 50 55 60 65 70 75 80 2. Soil descriptions and stratum lines are interpretive and actual changes may be gradual. Sample S-12 S-13 S-14 S-15 S-16 S-17 S-18 3. uses designations are based on visual manual classification (ASTM D 2488) unless otherwise supported by laboratory testing (ASTM D 2487). 4. Groundwater level. if indicated, is at time of drilling (ATD) or for date specified. Level may vary with time. 15 16 21 15 STANDARD PENETRATION RESISTANCE • Blows per Foot 0 10 20 r • ' r 30 40 r \ C \ -\ • • I -•: . I._ \ c• .. C • . ' LAB TESTS 50+ "GS C \ C r 50/3 " • r - - - r C C " 0 20 40 60 80 100+ • Water Content in Percent .. .. HIJRTCROWSER 7508-02 FigureA-3 6107 212 Q r ~ r D " ~ ~ D <.> <.> I ;;: " ~ m N 0 ro 0 ~ r ~ 0 ~ " z ~ D m ~ w z Boring Log HC-3 Location: See Figure 2. Approximate Ground Surface Elevation: 21 Feet Horizontal Datum: Vertical Datum· Drill Equipment: Hollow Stem Auger Hammer Type: 140 lb SPT Hole Diameter: inches Logged By: C. Brown Reviewed By: J. Wagner STANDARD PENETRATION RESISTANCE LAB TESTS & (PIO) ' uses Graphic Depth Class Log Soil Descriptions in Feet Sample ML Very soft to soft, wet, orange mottled gray 0 SILT. S-1 5 S-2 SM Loose, wet, red-brown, trace to slightly silty S-3 SAND with interbedded silt lenses. '° IZ ATD S-4 SP Medium dense, wet, gray to brown, gravelly SAND. S-5 15 S-6* '-Slight petroleum-like odor at 17.5-foot depth. S-7 '',Sandy gravel with wood fragment (4-inch). 20 S-8 ~Trace of wood fragments. Becomes dense. 25 S-9 30 S-10 Bottom of Boring at 31.5 Feet. Started 06118107. Completed 06/18107. "'Sheen observed on groundwater in sampler 35 at sample depth of 15 feet. 40 1. Refer to Figure A-1 for explanation of descriptions and symbols. 2. Soil descriptions and stratum lines are interpretive and actual changes may be gradual. 3. uses designations are based on visual manual classification (ASTM D 2488) unless otherwise supported by laboratory testing (ASTM D 2487). 4. Groundwater level, if indicated, is at time of drilling (ATD) or for date specified. Level may vary with time. 0 1 1 1 1 2 1 2 ' 1 2 ' 6 ' 12 4 6 9 4 5 3 9 15 19 8 13 19 • Blows per Foot 0 10 20 30 ~ ~ ~ • C : f,< -+ ~ -• • . " -• ~ . .. - : I ·K • -/ : .. .. ~ ~ • " - • - - - - - - 0 20 40 60 • water Content in Percent -.. 7508-02 FigureA-4 40 50 + CAL . (5.3) (5.9) 80 100+ 6/07 Test Pit Log TP-1 Location: See Figure 2. Approximate Ground Surface Elevation: 21 Feet ' Logged By: Reviewed By: USCS Graphic Class log ML ML ML ML Soil Descriptions (Soft), moist, brown, slightly sandy SILT with organic material. (Medium stiff), moist, brown and gray with orange mottling, slightly sandy SILT with organic material. (Medium stiff to stiff), moist, gray and brown with orange mottling, clayey SILT with abundant wood pieces. (Medium stiff), wet, dary gray, fine sandy SILT. Bottom of Test Pit at 9.0 Feet. Started 12/01/00. Completed 12/01/00. Test Pit Log TP-2 Location: See Figure 2. Approximate Ground Surface Elevation: 23 Feet Logged By: Reviewed By: uses Graphic Class Log Soi I Descriptions ML {Soft), moist, light brown, slightly sandy SILT wtth abundant organic material. SM/ML (Loose to medium dense), damp, very silty SAND with interbedded SILT and organic material. SP Ii (Loose), dry, gray and brown, fine SAND. ML (Medium stiff to stiff), moist, gray with orange mottling, slightly sandy, clayey SILT with wood debris. Bottom of Test Pit at 9.0 Feet. Started 12/01/00. Completed 12/01/00. 1. Refer to Figure A-1 for explanation of descriptions and symbols. Horizontal Datum Vertical Datum: Depth in Feet 0 r r f-5 r r f-10 f- r Sample S-1 S-2 S-3 J/. S-4 ATD Horizontal Datum: Vertical Datum: Depth in Feet 0 - 5 - -10 - S-1 S-2 S-3 S-4 Sample 2. Soil descriptions and stratum lines are interpretive and actual changes may be gradual. 3. uses designations are based on visual manual classification (ASTM D 2488) unless otherwise supported by laboratory testing (ASTM D 2487). 4. Groundwater conditions, if indicated, are at time of excavation. Conditions may vary with time. Water Content in Percent 41 52 50 39 Water Content in Percent 29 30 5 62 .. .. 7508 Figure A-5 PIO PIO 12100 LAB TESTS LAB TESTS ' Test Pit Log TP-3 Location: See Figure 2. Horizontal Datum: Approximate Ground Surface Elevation: 23 Feet Logged By: Reviewed By USCS Graphic Class Leg Soil Descriptions ML (Soft), moist, light brown, slightly sandy SILT with abundant organic material. ML (Medium stiff), moist, gray and light brown with orange mottling, slightly sandy SILT with organic material. ML (Medium stiff to stiff), moist, light gray with orange mottling, 1 clayey SILT. Bottom of Test Pit at 10.0 Feet. Started 12101100. Completed 12101/00. Test Pit Log TP-4 Vertical Datum: Depth in Feet 0 - -5 - ,-10 - S-1 S-2 S-3 Sample Location: See Figure 2. Horizontal Datum: Approximate Ground Surface Elevation: 21 Feet Vertical Datum: Logged By: Reviewed By: USCS Graphic Class Log Soil Descriptions ML (Soft to medium stiff), moist, dark brown, slightly sandy SILT. with abundant organic material. SP > (Loose), moist, brown and gray, fine to medium SAND. ML (Soft), damp, light brown and light gray with orange mottling, slightly sandy SILT. ML (Medium stiff). moist to wet, gray with orange mottling, slightly sandy, clayey SILT with some organic material. ML (Medium stiff), moist to wet, dark gray SILT. Bottom of Test Pit at 10.0 Feet. Started 12101100. Completed 12/01/00. 1. Refer to Figure A-1 for explanation of descriptions and symbols. Depth in Feet 0 r 5 a f- 'Si. 10 ATD a " 2. Soil descriptions and stratum lines are interpretive and actual changes may be gradual. 3. uses designations are based on visual manual classification (ASTM D 2488) unless otherwise supported by laboratory testing (ASTM D 2487). 4. Groundwater conditions. if indicated, are at time of excavation. Conditions may vary with lime. S-1 S-2 S-3 S-4 S-5 Sample Water Content in Percent 30 38 41 Water Content in Percent 37 15 24 35 38 .. .. 7508 Figure A-6 PID PID 12/00 LAB TESTS LAB TESTS Test Pit Log TP-5 Location: See Figure 2. Approximate Ground Surface Elevation 20 Feet Horizontal Datum· Vertical Datum: Logged By· Reviewed By: USCS Graphic Class Log Soil Descriptions ML Ill (Soft to medium stiff), moist. dark brown, slightly sandy SILT with abundant organic material. SP (Loose), moist, grat and brown, fine SAND. ML (Soft to medium stiff), dry to damp, light brown with orange mottling, slightl~ sandy SILT. ML (Medium stiff to stiff), moist to wet, gray with orange mottling, clayey SILT with organic material. ML (Medium stiff), wet, dark gray, fine sandy SILT. Caving Bottom of Test Pit at 10.0 Feet. Started 12/01/00. Completed 12/01/00. 1. Refer to Figure A-1 for explanation of descriptions and symbols. Depth in Feet 0 c c -, 5 - !l. 10 ATD - 2. Soil descriptions and stratum lines are interpretive and actual changes may be gradual. 3. uses designations are based on visual manual classification (ASTM D 2488) unless otherwise supported by laboratory testing (ASTM D 2487). 4. Groundwater conditions, if indicated, are at time of excavation. Conditions may vary with time. Sample S-1 S-2 S-3 S-4 S-5 Water Content in Percent 40 8 20 38 35 .. .. 7508 Figure A-7 LAB PIO TESTS 12100 Hart Crowser 7508-02 July 18, 2007 APPENDIX B LABORATORY TESTING PROGRAM Ill -~ 'Cl C 4) Q Q <( APPENDIX B .LABORATORY TESTING PROGRAM A laboratory testing program was performed for this study to evaluate the basic index and geotechnical engineering properties of the site soils. The tests performed and the procedures followed are outlined below. Soil Classification Field Observation and Laboratory Analysis. Soil samples from the explorations were visually classified in the field and then taken to our laboratory where the classifications were verified in a relatively controlled laboratory environment. Field and laboratory observations include density/consistency, moisture condition, and grain size and plasticity estimates. The classifications of selected samples were checked by laboratory tests such as Atterberg limits determinations and grain size analyses. Classifications were made in general accordance with the Unified Soil Classification (USC) System, ASTM D 2487, as presented on Figure 8-1. Water Content Determinations Water contents were determined for most samples recovered in the explorations in general accordance with ASTM D 2216, as soon as possible following their arrival in our laboratory. The results of these tests are plotted or indicated at the respective sample depth on the exploration logs. In addition, water contents are routinely determined for samples subjected to other testing. These are also presented on the exploration logs. Atterberg Limits (AL) Hart Crowser 7508-02 July 18, 2007 We determined Atterberg limits for selected fine-grained soil samples. The liquid limit and plastic limit were determined in general accordance with ASTM D 4318-84. The results of the Atterberg limits analyses and the plasticity characteristics are summarized on the Liquid and Plastic Limits Test Report, Figure 8-2. This relates the plasticity index (liquid limit minus the plastic limit) to the liquid limit. The results of the Atterberg limits tests are shown graphically on the boring logs as well as where applicable on figures presenting various other test results. Page 8-1 Grain Size Analysis (GS) Hart Crowser 7508-02 July 18. 2007 Grain size distribution was analyzed on representative samples in general accordance with ASTM D 422. Wet sieve analysis was used to determine the size distribution greater than the U.S. No. 200 mesh sieve. The results of the tests are presented as curves on Figures B-3, plotting percent finer by weight versus grain size. J:\jobs\750802\Harper Geotech Report.doc Page B-2 Unified Soil Classification (USC) System Soil Grain Size ~--------·-------·---~-~--- Size of Opening In Inches Number of Mesh per Inch Grain Size In Minimelres ~--------__________ --~~----~i=us~s'='"='="=''~-----~------____ _ Grain Size in Millimetres COBBLES I GRAVEL I SAND SILT and CLAY -·----- Coarse-Grained Soils Fine-Grained Solis Coarse-Grained Soils G w I G p I G M I G C s w I s p I. s M I s .. ,,., C Clean GRAVEL <5% fines \ GRAVEL with >12% fines Clean SAND <5% fines y SAND with >12% fines GRAVEL >50% coan;e fraction larger than No. 4 SAND >50% coarse fraction smaller than No. 4 Coarse-Grained Soils >50% larger than No. 200 sieve ( 1D00 \>4 for G W GWandSW -0 ) 1 SW \ 101 >6 or ( (D )' \ & 1~ . 30 / ~ 3 ,D 10 X Doq, G Mand S M Atterberg limits below A line with Pl <4 ----- G P and SP Clean GRAVEL or SAND nol meeting requirements for G W and SW G C and S C Atterberg limits above A Line with Pl > 7 * Coarse-grained soils with percentage of fines between 5 and 12 are considered borderline cases requiring use of dual symbols. D10 , 0 30 , and D60 are the particles diameter of which 10, 30, and 60 percent, respectively, of the soil weight are finer. Fine-Grained Soils ML CL OL MH CH OH Pt SILT CLAY Organic SILT CLAY Organic Highly Or9.anic Soils with Liquid Limit <50% Soils with Liquid Limit >50% Soils - Fine-Grained Soils >50% smaller than No. 200 sieve 60 ~--~---,~--~---,----,----,----,----,----,----,50 50 -8 40 E f 30 20 10 CL M HorO H -CL-ML 0 ""----l-----'------'--------'-----'------'-----'---.....L-------'------' 0 10 20 30 40 50 60 70 60 90 Liquid Limit SRF G,_, SJn (B-1).cdr 3"0d -.. 7508-02 Figure B-1 50 40 30 20 10 6/07 Liquid and Plastic Limits Test Report / / Dashed line indicates the approximate / upper limit boundary for natural soils ~~-+---~/' I----+--/ --,-'/---+----+o~ -7"-=+----+----1 50 40 X w Cl ~ ~30 0 ~ Q. 20 10 • Source: HC-2 SILT • Source: HC-3 SILT Remarks: • • / / / / / / / / / / / / / / / o"' v~ I----+~/_/__ o"~-1----+---+---+---+---+----1 o<. v" . • ML orOL MH or OH 30 50 70 LIQUID LIMIT Location + Description LL PL Pl Sample No.: S-3 Depth: 7.5 46 37 9 Sample No.: S-2 Depth: 5 48 33 15 Project: Harper Client: Harper Engineering Location: Renton, Washington .. IIJ!RTCROWSER. 90 -200 7508-02 Figure 8-2 110 uses ML ML 61712007 Particle Size Distribution Test Report ~ ' ' 0 0 e e -~ ~ • ~ g al ii • . " -::: . • • • . 100 \ls- • • 90 '\ ' \ '\ . \ 80 .\ • ~\ ,: . . \: 1" 70 "" et: . I'~ ~ . ' LU 60 "'~ z LL \ f-"-._ I' z 50 LU u \ I\ I et: LU 40 Q_ I . \ 30 \ : \ \: \ . \ ~ \ 20 \ \, . '• "- . \ . "' 10 "'t---c ~ 0 ~ 100 10 1 0.1 0,01 O.Ou GRAIN SIZE -mm Vo COBBLEf %GRAVEL %SAND %SILT %CLAY • 0.0 41.0 53.1 5.9 • 0.0 25.2 64.4 10.4 .. 0.0 41.6 56.3 2.1 :x LL Pl D,. o,. o,. o,. D,. o,. c, C, • 20.388 5.067 3.311 1.387 0.506 0.257 1.48 19.75 • 9.107 1.109 0.58 0.263 0.127 0.87 15.48 .. 16.053 5.211 1.161 0.351 0.222 0.176 0.13 29.67 MATERIAL DESCRIPTION uses NAT.MOIST. • Slightly silty, very gravelly SAND SW-SM 13.1% • Slightly stlty, gravelly SAND SP-SM 22.1% • Very gravelly SAND SP 19.0% Remarks: • Project: Harper Engineering Building Client: Harper Engineering a Wood in sample • Source: HC-1 Sample No.: S-9* Depth: 25.0 to 26.5 • Source: HC-2 Sample No.: S-9 Depth: 25.0 to 26.5 " Source: HC-2 Sample No.: S-13 Depth: 45.0 to 46.5 " -.. 7508-02 61712007 HI.IRTCROWSER Figure B-3