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HomeMy WebLinkAboutStormwater Infiltration - GRD Engineering / Geo-Tech Reports - 8/21/2008 GeoResources, LLC Ph.253-896-1011 5007 Pacific Hwy. E.,Suite. 20 Fx.253-896-2633 Fife, Washington 98424 August 21, 2008 Blue Star Trust NE 431 Logyard Road Belfair, Washington 98528 (360) 275-0228 Geotechnical Consultation Stormwater Infiltration NE 431 Logyard Road Belfair,WA 98528 ParcelN . 123211300000, 123211400000 o Job No: BlueStarTrust.LogyardRd.L1 This letter provides engineering recommendations for the infiltration of collected storm water at the subject site, a proposed expansion of the North Mason Fiber Company, located in Mason County, Washington. The site is currently undeveloped and bordered by railroad tracks to the west, the existing commercial development to the north, vacant land and a utility easement to the east and an existing large lot single family development to the south. The approximate location of the site is shown on Figure 1. During our recent site visit we observed the excavation of four test pits at various locations across the site. A site plan showing the locations of the test pits is included as Figure 2. The site is mapped by the NRCS maps as Indianola loamy sand (lb), which is derived from sandy glacial outwash. A copy of the NRCS map is shown on Figure 3. The soils encountered in the test pits were consistent with recessional outwash sand with some lenses of gravel and trace silt. Slightly increased silt content was observed at lower elevations. The soils appeared to be consistent across the site where the excavations were performed. The soils encountered in the test pits were logged visually classified per ASTM 2488-90. A description of the classification is included as Figure 4. A copy of the Test Pit logs is attached as Figure 5. Representative samples were obtained and submitted for laboratory grain size analysis. Based on our test pits, the available soil maps, and our experience in the area, onsite stormwater infiltration does appear possible. Infiltration rates in this letter are based on Table 3.8 in the 2005 Department of Ecology Stormwater Management Manual for Western Washington. Two of the sarnples were submitted for grain size analysis and had D,o values of .1338 and .256 respectively. These correlate to long term infiltration rates of 2.0 and 3.5 inches per hour per the DOE Manual. Because the site conditions were generally uniform where excavated, and the prescribed rates are long term, no additional factor of safety is required by the manual for these rates. Copies of the lab tests are attached in Appendix A. Based on our experience with similar soils, it is our opinion that the actual infiltration rates for these soils may be higher. In order to use higher rates than the ASTM grain size correlations, field infiltration tests can be performed at the locations of the proposed systems and at the proposed infiltration depths. Appropriate factors of safety will need to be applied to the rates obtained from the field tests. Blue Star Trust—Stormwater August 21,2008 We appreciate the opportunity to be of service on this project. Should you have need of additional information or services please call. Yours Very Truly, GeoResources, LLC - r Dana C. Biggerstaff, Eli, Staff Engineer ok wash�� 3H, bg [oafs \ j `\ s �_ tJ BRAT)EY P.BIGGBR55 1717 EJCP RE 0131 Brad P. Biggerstaff, LEG/LN6 W. Glen Coad, PE Principal Principal WGC:BPB:dcb DocID:BlueStar-rrust.LogyardRdIl Attachments: Figure 1--Site Vicinity Map Figure 2—Site Plan Figure 3—Soil Map Figure 4—USCS Classification Figure 5—Test Pit Logs Appendix A—Laboratory Results a• J' /j'- t �,.�• �Ei Natbnai� J:f ' 1L. r ( , r A (30O i x ers.'CII d hu reseed. � t' Approximate Site Location mI- J Not to Scale GeoResources, LLC Site Vicinity Map 5007 Pac'rfic Highway East, Suite 20 North Mason Fiber Company Fife,Washington 98424 NE 431 Logyard Road Phone: 253-896-1011 Belfalr,Washington Fax: 253-896-2633 DocID:BlueStarTrustLogyardRd August 2008 Figure 1 rr _ r / r / / / I I 'r I / < i J / Approximate Location of Test Pit: Scale: 1" = 150' GeoResources, LLC Site Plan 5007 Pacific Highway East, Suite 20 North Mason Fiber Company Fife,Washington 98424 NE 431 Logyard Road Phone: 253-896-1011 Belfair,Washington Fax: 253-896-2633 DocID:BlueStarTrustLogyardRd.SP August 2008 Figure 20 .aY y arP rt �t y ,�7 ix �� ka.ors 1 ' '• � .fll eW .�C1 77 I. �` NFL jh 3 Y Approximate Site Location SCS SCS Parent Slopes Erosion Soil Soil Name Material (in percent) Hazard Type lb Indianola loamy sand Sandy glacial outwash 0 to 6 Slight S Not to Scak GeoResources, LLC MRCS Soils Map 5007 Pacific Highway East, Suite 20 North Mason Fiber Company Fife, Washington 98424 NE 431 Logyard Road Phone: 253-896-1011 Belfair, Washington Fax: 253-896-2633 DocID:BlueStarTrust.LogyardRd.SCS August 2008 Figure 3 SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP GROUP NAME SYMBOL GRAVEL CLEAN GW WELL-GRADED GRAVEL,FINE TO COARSE GRAVEL GRAVEL COARSE GP POORLY-GRADED GRAVEL GRAINED More than 50% SOILS Of Coarse Fraction GRAVEL GM SILTY GRAVEL Retained on WITH FINES No.4 Sieve GC CLAYEY GRAVEL More than 50% SAND CLEAN SAND SW WELL-GRADED SAND, FINE TO COARSE SAND Retained on No.200 Sieve SP POORLY-GRADED SAND More than 50% Of Coarse Fraction SAND SM SILTY SAND Passes WITH FINES No.4 Sieve SC CLAYEY SAND SILT AND CLAY INORGANIC ML SILT FINE CL CLAY GRAINED SOILS Liquid Limit Less than 50 ORGANIC OL ORGANIC SILT,ORGANIC CLAY SILT AND CLAY INORGANIC MH SILT OF HIGH PLASTICITY, ELASTIC SILT More than 50% Passes CH CLAY OF HIGH PLASTICITY,FAT CLAY No.200 Sieve Liquid Limit 50 or more ORGANIC OH ORGANIC CLAY,ORGANIC SILT HIGHLY ORGANIC SOILS PT PEAT NOTES: SOIL MOISTURE MODIFIERS: 1. Field classification is based on visual examination of soil Dry- Absence of moisture,dry to the touch In general accordance with ASTM D2488-90. Moist- Damp,but no visible water 2, Soil classification using laboratory tests is based on ASTM D2487-90. Wet- Visible free water or saturated, usually soil is obtained from below water table 3. Description of soil density or consistency are based on interpretation of blow count data,visual appearance of soils,and or test data. GeoResources, LLC Soil Classification System 5007 Pacific Highway East, Suite 20 North Mason Fiber company Fife, Washington 98424 NE 431 Logyard Road Phone: 253-896-1011 Beffair, Washington Fax: 253-896-2633 DocID: BIueStarTrust.Log yard Rd.USCS August 2008 Figure 4 Test Pit TP-1 Location: in the NW corner of the site, low area Depth (ft) Soil Type Soil Description 0.0 0.5 Topsoil 0.5 - 10.0 SP Brn/gry SAND w/trace silt (med dense, moist) 10.0 12.0 SP Brn/gry SAND w/some silt and trace gravel (med dense, moist) Moderate caving observed from 3 to 9 feet No groundwater seepage observed Test Pit TP-2 Location: in the NW portion of the site, upland and -75 feet S of TP-1 Depth (ft) Soil Type Soil Description 0.0 - 0.5 Topsoil 0.5 - 3.0 SP Brn SAND w/silt(loose, moist) 3.0 - 6.0 GP Brn GRAVEL w/sand, cobbles and trace silt(loose to med dense, moist) 6.0 14.0 SP Gry SAND w/some gravel and trace silt(med dense, moist) Moderate caving observed from 3 to 10 feet No groundwater seepage observed Test Pit TP-3 Location: in the central portion of the site Depth (ft) Soil Type Soil Description 0.0 - 0.5 Topsoil 0.5 - 4.0 SP Brn SAND w/silt and some organics (rootlets) (loose to med dense, moist) 4.0 - 18.0 SP Gry SAND w/some gravel (med dense, moist) Moderate caving observed from 2 to 14 feet No groundwater seepage observed Test Pit TP-4 Location: in the SW portion of the site in depression Depth (ft) Sail Type Soil Description 0.0 - _75 Topsoil .75 - 3.0 SP Lt. Brn SAND w/silt(loose, moist) 3.0 6..5 SP Gry SAND w/some silt and gravel (med dense, moist) 6.5 15.0 SP Gry SAND w/some silt(in lenses) (med dense to dense, moist) Moderate caving observed from 3 to 9 feet No groundwater seepage observed TEST PIT LOGS GeoResources, LLC North Mason Fiber Company 5007 Pacific Highway East, Suite 20 NE 431 Logyard Road Fife,Washington 98424 Belfair, Washington Phone: 253-896-1011 Fax: 253-896-2633 JOB#BlueStarTrust.LogyardRdl August 2008 Figure 5 Appendix "A" L Particle Size Distribution Report o0 _< < < �cia o (p� o fpp a �_ g 100 0 I 'I � I ;I` I 10 I 80 t t ; 'i 1 I t t t — 20 i� I I I I I...;I; 70 i 30 i i .I i b I I II I :`Ii i I I I I I; i ! m w 60 } �i + ( i i i'I i 40 n LL I I Ili I I I I I� I I m ZZ 50 n U ; • j t D I LU 40 I 4 �l i ' !: I 1 - — 60 II I I I I I I I II, I M I I jl l i l I ; ! I I I I I I • I I 30 - 70 I I •I I I I I ' I � I I I I I I 20 I I I I I I I I I I I 80 10 t... i _ t t. 90 p I I ! I i I I ! I 100 100 10 1 0.1 0.01 0.001 GRAIN SIZE-mm. %+3" %Gravel %Sand %Fines Coarse Fine Coarse Medium Fine SiltI Clay 0.0 0.0 0.6 0.9 1 12.4 81.6 4.5 SIEVE PERCENT SPEC.* PASS? Material Description SIZE FINER PERCENT (X-NO) Poorly Graded Sand 3/8 100.0 Sampled by Dana Biggerstaff on 7/31/2008 #4 99.4 Tested by Tim Bergstrom on 8/5/2008. #10 98.5 #20 96.4 Atterberg Limits #40 86.1 PL= LL= PI= #60 46.4 Coefficients #100 13.9 D85= 0.4160 D60= 0.2945 D60= 0.2613 #200 4.5 D36= 0.2010 D15= 0.1541 D10= 0.1338 Cu= 2.20 Cc= 1.03 Classification USCS= SP AASHTO= Remarks Entered by Tim Bergstrom on 8/6/2008 (no specification provided) Sample Number: 080311 Depth: 10'-12' Location: S-1,-rn-I Date: 8/6/2008 GeoResources, LLC Client: Blue Star Trust Project: Log Yard Road Fife WA Project No: BlueStarTnist.Lo YardRoad FI ure Tested By: Tim Bergstrom Checked By: Dana Biggerstaff Particle Size Distribution Report C C O O O C t o of N 104 \ :C ae xk se I I II I 90 r- � - " i _ 1- ll 1 j 10 ! I f I I I I I I I I Il 80 1 --E--- - - 20 70 - - 30 M W 60 - -- { . I 40 m z I II I I I I I I I I I z I i I i l l I I I I I f 50 Z 50 I I I I I I I I I I I I I ! 7 n LU CD ! W W 40 �.._ ! � i- - i r - 60 30-- 1 _ 70 i � -- I - ISO 20 10 I . 90 I I I I •I I I I I I I I I ! oLLI I i I I I I I I 100 100 10 1 0.1 0.01 0.001 GRAIN SIZE-mm. %+3„ %Gravel %Sand _ %Fines_ __.........__.... Coarse I Fine Coarsel Medium Fine Silt Clay 0.0 31.7 13.5 6.2 25.2 21.6 1.8 SIEVE PERCENT SPEC.` PASS? Material Description SIZE FINER PERCENT (X=NO) Poorly Graded Sand with Gravel 2-1/2 100.0 Sampled by Dana Biggerstaff on 7/31/2008 2 93.7 Tested by Tim Bergstrom on 8/4/2008 , 1-1/2 87.3 Atterberg Limits 1-1/4 76.6 PL= LL= PI= 1 72.1 3/4 68.3 Coefficients 1/2 62.8 D85= 36.5492 D60= 8.9254 D50= 2,4400 3/8 60.5 D30= 0.5448 D15= 0.3152 D10= 0.2560 #4 54.8 Cu= 34.87 Cc= 0.13 #10 48.6 Classification #20 39.3 USCS= SP AASHTO= #40 23.4 #60 9.5 Remarks #100 4.0 Entered by Tim Bergstrom on 8/7/2008 #200 1.8 (no specification provided) Sample Number: 080310 Depth: 8'-12, Date: 8/7/2008 Location: S-1, TP 3 GeoResources, LLC client: Blue Star Trust Project: Log Yard Road Fife WA Project No: B1ueStarTrust.Lo YardRoad Figure Tested By: Tim Bergstrom Checked By: Dana BiggerstafF H North Mason Fiber Company Stormwater Analysis Summary This summary contains the technical and background information in support of the proposed North Mason Fiber Company storm drainage system. The analysis included in this document summarizes the design of the proposed stormwater facilities. The project site is approximately 10 acres in size and located within the northeast quarter of Section 21, Township 23 North, Range 1 West, W.M., Mason County, Washington. Currently, the site is proposed to be cleared and graded to allow for temporary storage of materials on portions of the site, and will focus on preparing the property for future development. Topography on site is rolling with slopes generally less than 15 percent, and the project site sloping generally to the southwest. The site is classified, per the NRCS Soil Survey of Mason County, Washington as consisting of Indianola loamy sand (Ib). A geotechnical letter was prepared for the project site by GeoResources, LLC, dated August 21, 2008 and should be.referenced for further information. Drainage from the developed site will be conveyed to a wetpond for quality control prior to discharge to a retention pond for quantity control. The project's on-site facilities were analyzed using the Western Washington Hydrology Model(WWHM) software. The following assumptions were used for the analysis: 1. The developed site was assumed to be 100 percent impervious. 2. The design infiltration rate was assumed to be 10 inches per hour. It should be noted that this rate was determined based on discussions with GeoResources, LLC, and the assumption that further field infiltration tests would be performed prior to construction to verify this rate. Refer to the attached calculations for further information. 8-Z: Jar e� of W co,�, 40 oNAL Western Washington Hydrology Model PROJECT REPORT Project Name: 29577 Site Address: Sec 21, T23N, R1W City Belfair Report Date 8/25/2008 Gage Quilcene Data Start 1955/10/01 Data End 1999/09/30 Precip Scale: 1.22 PREDEVELOPED LAND USE Name Overall Basin Bypass: No Groundwater: No Pervious Land Use Acres A B, Forest, Mod 9.67 Impervious Land Use Acres Element Flows To: Surface Interflow Groundwater Name Overall Basin Bypass: No Groundwater: No Pervious Land Use Acres Impervious Land Use Acres PARKING MOD 9.67 Element Flows To: Surface Interflow Groundwater Trapezoidal Pond 1, Trapezoidal Pond 1, Name Trapezoidal Pond 1 Bottom Length: 200ft. Bottom Width: 75ft. Depth 6ft. Volume at riser head 2.0527ft. 689,416 GF) Infiltration On Infiltration rate 20 Infiltration saftey factor 0.5 Side slope 1: 2 To 1 Side slope 2: 2 To 1 Side slope 3: 2 To 1 Side slope 4: 2 To 1 Discharge Structure Riser Height: 5 ft. Riser Diameter: 18 in. Element Flows To: Outlet 1 Outlet 2 Pond Hydraulic Table Stage(ft) Area(acr) Volume(acr-ft) Dschrg(cfs) Infilt(cfs) 100.0 0.344 0.000 0.000 0.000 100.1 0.346 0.023 0.000 3.472 100.1 0.348 0.046 0.000 3. 472 100.2 0.349 0.069 0.000 3.472 100.3 0.351 0.093 0.000 3.472 100.3 0.353 0. 116 0.000 3.472 100.4 0.355 0. 140 0.000 3.472 100.5 0.356 0.163 0.000 3.472 100.5 0.358 0.187 0. 000 3.472 100. 6 0.360 0.211 0. 000 3.472 100.7 0.361 0.235 0.000 3.472 100.7 0.363 0.259 0.000 7 3 4 2 100.8 0.365 0.284 0.000 3. 472 100. 9 0.367 0.308 0. 000 3. 472 100. 9 0.368 0.332 0. 000 3.472 101.0 0.370 0.357 0. 000 3.472 101.1 0.372 0.382 0.000 3.472 101. 1 0.373 0.407 0.000 3.472 101.2 0.375 0.432 0.000 3.472 101.3 0.377 0.457 0. 000 3.472 101.3 0.379 0.482 0.000 3.472 101.4 0.380 0.507 0. 000 3. 472 101.5 0.382 0.533 0.000 3.472 101.5 0.384 0.558 0.000 3.472 101.6 0.386 0.584 0.000 3.472 101.7 0.387 0. 610 0.000 3.472 101.7 0.389 0. 635 0.000 3.472 101.8 0.391 0.661 0.000 3.472 101. 9 0.393 0. 688 0.000 3.472 101. 9 0.395 0.714 0.000 3.472 102.0 0.396 0.740 0.000 3.472 102.1 0.398 0.767 0.000 3.472 102. 1 0.400 0.793 0.000 3.472 102.2 0.402 0.820 0.000 3.472 102.3 0.403 0.847 0.000 3.472 102.3 0.405 0.874 0.000 3.472 102. 4 0.407 0. 901 0.000 3.472 102.5 0.409 0. 928 0.000 3.472 102.5 0.411 0.955 0.000 3.472 102.6 0. 412 0. 983 0.000 3.472 102.7 0.414 1.010 0.000 3.472 102.7 0.416 1.038 0.000 3.472 102.8 0.418 1. 066 0.000 3.472 102. 9 0.420 1.094 0. 000 3.472 102. 9 0. 422 1. 122 0. 000 3.472 103.0 0.423 1. 150 0.000 3.472 103. 1 0.425 1.178 0.000 3.472 103. 1 0.427 1.207 0.000 3.472 103.2 0.429 1.235 0.000 3.472 103.3 0.431 1.264 0.000 3.472 103.3 0.433 1.293 0.000 3. 472 103.4 0.434 1.322 0.000 3. 472 103.5 0.436 1.351 0.000 3.472 103.5 0.438 1.380 0.000 3.472 103. 6 0.440 1.409 0.000 3.472 103.7 0.442 1.438 0.000 3.472 103.7 0. 444 1. 468 0.000 3.472 103.8 0.446 1.498 0.000 3.472 103. 9 0.447 1.527 0.000 3.472 103. 9 0.449 1.557 0.000 3.472 104.0 0.451 1.587 0.000 3.472 104.1 0.453 1. 617 0.000 3. 472 104.1 0. 455 1. 648 0.000 3.472 104 .2 0. 457 1. 678 0.000 3.472 104.3 0.459 1.709 0.000 3.472 104.3 0.461 1.739 0.000 3. 472 104.4 0.463 1.770 0.000 3.472 104.5 0.464 1.801 0.000 3. 472 104.5 0.466 1.832 0.000 3.472 104 .6 0.468 1.863 0.000 3. 472 104.7 0.470 1.894 0.000 3.472 104.7 0. 472 1. 926 0.000 3. 472 104.8 0. 474 1. 957 0.000 3. 472 104. 9 0. 476 1. 989 0.000 3. 472 104 . 9 0. 478 2.021 0.000 3.472 105.0 0. 480 2.053 0.000 3.472 105. 1 0. 482 2.085 0.251 3.472 105. 1 0. 484 2.117 0.711 3.472 105.2 0.486 2. 149 1.307 3.472 105.3 0. 488 2.182 2.012 3.472 105.3 0.489 2.214 2.811 3.472 105.4 0.491 2.247 3. 696 3.472 105.5 0.493 2.280 4. 657 3.472 105.5 0.495 2.313 5. 690 3. 472 105. 6 0.497 2.346 6.789 3. 472 105.7 0.499 2.379 7. 952 3.472 105.7 0.501 2.412 9. 174 3.472 105.8 0.503 2.446 10.45 3. 472 105.9 0.505 2.479 11.79 3. 472 105. 9 0.507 2.513 13.17 3.472 106.0 0.509 2.547 14. 61 3.472 106.1 0.511 2.581 16.09 3.472 MITIGATED LAND USE ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.460369 5 year 1.240929 10 year 1.720794 25 year 2. 176762 50 year 2.411096 100 year 2.575593 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0 5 year 0 10 year 0 25 year 0 50 year 0 100 year 0 Yearly Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1957 5. 471 0.000 1958 0.348 0.000 1959 1.282 0.000 1960 0.745 0.000 1961 0.254 0.000 1962 1.099 0.000 1963 0.093 0.000 1964 0. 479 0.000 1965 0.309 0.000 1966 0. 133 0.000 1 OC17 1 Oro n nnn 1968 0.778 0.000 1969 0. 663 0.000 1970 0.261 0.000 1971 0.376 0.000 1972 1. 171 0.000 1973 1.085 0.000 1974 0. 622 0.000 1975 0.866 0.000 1976 0. 639 0.000 1977 1.352 0.000 1978 0.075 0.000 1979 0.183 0.000 1980 0.192 0.000 1981 1.008 0.000 1982 0.434 0.000 1983 0.035 0.000 1984 0.722 3.741 1985 0. 002 0.000 1986 0.001 0.000 1987 0.372 0.000 1988 0.833 0.000 1989 0.047 0.000 1990 0.205 0.000 1991 0.004 0.000 1992 0. 691 0. 000 1993 0.311 0.000 1994 0.108 0.000 1995 0.768 0.018 1996 0.760 0.000 1997 0.495 0.000 1998 0.097 0.000 1999 0. 695 0.000 2000 1. 190 0.788 Ranked Yearly Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 5.4713 3.7407 2 1.8600 0.7878 3 1.3516 0.0185 4 1.2823 0.0000 5 1.1903 0.0000 6 1.1715 0.0000 7 1.0987 0.0000 8 1.0847 0.0000 9 1.0082 0.0000 10 0.8665 0.0000 11 0.8331 0.0000 12 0.7779 0.0000 13 0.7681 0.0000 14 0.7601 0.0000 15 0.7452 0.0000 16 0.7217 0.0000 17 0. 6951 0.0000 18 0. 6913 0.0000 19 0. 6629 0.0000 20 0. 6386 0.0000 21 0.6225 0.0000 22 0.4951 0.0000 23 0.4792 0.0000 24 0.4338 0.0000 25 0.3759 0.0000 26 0.3723 0.0000 27 0.3482 0.0000 28 0.3112 0.0000 29 0.3087 0.0000 30 0.2610 • 0.0000 31 0.2542 0.0000 32 0.2055 0.0000 33 0.1921 0.0000 34 0.1835 0.0000 �cz n 1 � :�1� n nnnn 36 0. 1076 0.0000 37 0. 0968 0.0000 38 0. 0933 0.0000 39 0. 0755 0.0000 40 0.0474 0.0000 41 0.0350 0.0000 42 0.0044 0.0000 43 0.0017 0.0000 44 0.0014 0.0000 POC #1 Facility FAILED duration standard for 1+ flows. Flow(CFS) Predev Dev Percentage Pass/Fail 0.2302 265 15 5 Pass 0.2522 231 15 6 Pass 0.2742 200 15 7 Pass 0.2963 182 15 8 Pass 0.3183 150 15 10 Pass 0.3403 134 15 11 Pass 0.3624 121 15 12 Pass 0.3844 101 15 14 Pass 0.4064 84 15 17 Pass 0.4284 80 14 17 Pass 0.4505 75 13 17 Pass 0.4725 71 13 18 Pass 0.4945 66 12 18 Pass 0.5166 63 12 19 Pass 0.5386 58 12 20 Pass 0.5606 50 12 24 Pass 0.5827 45 12 26 Pass 0. 6047 39 12 30 Pass 0. 6267 33 12 36 Pass 0.6487 31 12 38 Pass 0.6708 30 12 40 Pass 0.6928 27 12 44 Pass 0.7148 25 12 48 Pass 0.7369 23 12 52 Pass 0.7589 22 11 50 Pass 0.7809 18 11 61 Pass 0.8029 18 7 38 Pass 0.8250 17 7 41 Pass 0.8470 15 7 46 Pass 0.8690 13 7 53 Pass 0.8911 13 7 53 Pass 0. 9131 13 7 53 Pass 0. 9351 12 7 58 Pass 0. 9572 11 7 63 Pass 0. 9792 10 7 70 Pass 1.0012 10 7 70 Pass 1.0232 9 7 77 Pass 1.0453 9 7 77 Pass 1.0673 9 7 77 Pass 1.0893 8 7 87 Pass 1.1114 6 7 116 Fail 1.1334 6 7 116 Fail 1.1554 6 7 116 Fail 1.1774 5 7 140 Fail 1. 1995 4 7 175 Fail 1.2215 4 7 175 Fail 1.2435 4 6 150 Fail 1.2656 4 6 150 Fail 1.2876 3 6 200 Fail 1.3096 3 6 200 Fail 1.3317 3 6 200 Fail 1.3537 2 6 300 Fail 1.3757 2 6 300 Fail 1.3977 2 6 300 Fail 1.4198 2 6 300 Fail 1 AAA 0 7 a ')nn T 4 1 1.4638 2 6 300 Fail 1.4859 2 6 300 Fail 1.5079 2 6 300 Fail 1.5299 2 6 3Q0 Fail 1.5519 2 6 300 Fail 1.5740 2 6 300 Fail 1.5960 2 6 300 Fail 1.6180 2 6 300 Fail 1.6401 2 6 300 Fail 1.6621 2 6 300 Fail 1.6841 2 6 300 Fail 1.7062 2 6 300 Fail 1.7282 2 6 300 Fail 1.7502 2 6 300 Fail 1.7722 2 6 300 Fail 1.7943 2 6 300 Fail 1.8163 2 6 300 Fail 1.8383 2 6 300 Fail 1.8604 1 - 6 600 Fail 1.8824 1 6 600 Fail 1.9044 1 6 600 Fail 1.9264 1 6 600 Fail 1.9485 1 6 600 Fail 1. 9705 1 6 600 Fail 1.9925 1 5 500 Fail 2.0146 1 5 500 Fail 2.0366 1 5 500 Fail 2.0586 1 5 500 Fail . 2.0807 1 5 500 Fail 2.1027 1 5 500 Fail 2.1247 1 5 500 Fail 2.1467 1 5 500 Fail 2.1688 1 5 500 Fail 2.1908 1 5 500 Fail 2.2128 1 5 500 Fail 2.2349 1 5 -500 Fail 2.2569 1 5 500 Fail 2.2789 1 5 500 Fail 2.3009 1 5 500 Fail 2.3230 1 5 500 Fail 2.3450 1 5 500 Fail 2.3670 1 5 500 Fail 2.3891 1 5 500 Fail 2.4111 1 5 500 Fail The development has an increase in flow durations from 1/2 predeveloped 2 year flow to the 2 year flow or more than a 10% increase from the 2 year to the 50 year flow. Water Quality SMP Flow and Volume for POC 1. On-line facility volume: 2.9198 acre-feet On-line facility target flow: 0.01 cfa. Adjusted for 15 min: 3.724 cfe. Off-line facility target flow: 1.9128 cfs. Adjusted for 15 min: 2.1614 cfa. This program and accompanying documentation is provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. Clear Creek Solutions and the Washington State Department of Ecology disclaims all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions and/or the Washington State Department of Ecology be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions or the Washington State Department of Ecology has been advised of the possibility of such damages. water Quality wet Pond CRUIe1 Too cell #1 Below Berm Cummulative Elevation Area (sf) volume (cf) volume (cf) 322.0000 11795.3349 11331.6130 61361.6716 321.0000 10867.8911 10420.8362 50030.0586 320.0000 9973.7814 9543.3935 39609.2223 319.0000 9113.0057 8699.2849 30065.8288 318.0000 8285.5642 7888. 5104 21366. 5439 317.0000 7491.4566 7111.0699 13478.0335 316.0000 6730.6832 6366.9635 6366.9635 315.0000 6003.2439 0.0000 0.0000 water Quality wet Pond A ��o) Cell #2 Below Berm Cummulative Elevation Area (sf) volume (cf) volume (cf) 322.0000 10923.6644 10511.2469 57727.9366 321.0000 10098.8294 9702.5739 47216.6896 320.0000 9306.3184 8926.2249 37514.1157 319.0000 8546.1315 8182.2000 28587.8908 318.0000 7818.2685 7470.4991 20405.6908 317.0000 7122.7297 6791.1222 12935.1917 316.0000 6459. 5148 6144.0694 6144.0694 315.0000 5828.6240 0.0000 0.0000 water Quality wet Pond CFk�M �coo Both cells Above Berm cummulative Elevation Area (sf) volume (cf) volume (cf) 324.0000 26192.4738 25461.8631 49480.7707 323.0000 24731.2524 24018.9076 24018.9076 322.0000 23306.5627 0.0000 0.0000 VOL-th-16- �51) 36Z GF t- S��-'Z cF t Z`F O , )01 CF )�3� .: Sffav� BE �oEav�f'TE infiltration Pond cummulative Elevation Area (sf) volume (cf) volume (cf) 324.0000 22549. 5927 21868.8443 111695.2808 323.0000 21188.0958 20523.6647 89826.4366 322.0000 19859.2335 19211.3603 69302.7719 321.0000 18563.4870 17932.1716 50091.4117 320.0000 17300.8563 16686.0988 32159.2400 319.0000 16071.3414 15473.1412 15473.1412 318.0000 14874.9410 0.0000 0.0000 cF Vol. 4w-44G0 = B9,�fi16 cF .. ,Sh�ci`� l3G �}066rVfh� FOR: FILE NO. /✓a117-;# Z9'S7f�- 2601 South 35th, Suite 200 TASK NO. Tacoma,Washington 98409 (253) 473-4494 P7/0 En Engineering, Fax: (253) 473-0599 /A 9 9d apex9apexengineering.net PREPARED BY: �L� DATE: CHECKED BY: SCALE: P � _ / Z tt w 4 = T / 3 zlx ns _ 6,5 - r File Edit ( Contents Search For Help On... About �- i � . . 701InfkmtoPOC`1Ming Flow Frequency 10E 2 Flow(CFS) 0701 2 Year — 5.2183 5 Year = 6.5098 (� 10 Year = 7.4146 25 Year = 8.6161 l0E 1 0 50 Year = 9.5548 00000000000000003,000000000000000 0 000 0 100 Year = 10.5321 aoae Nearly Peaks J l0E 0 1956 13.4968 L 1957 7.0464 1958 6.8613 1959 5.2562 1960 4.6332 10E-1 1961 5.8379 1 10 20 30 40 50 60 70 80 90 99 1962 5.2815 8741 Cumulative Probability,1 196 4 196 4.5156 4. ` '' 156 1965 3.4766 Durations Flow Frequency Water QS-IIty Hydrograph Wetland Fluctuation 1966 9.0311 Analyze datasets RUN ANALYSIS 1967 5.0041 1968 4.8341 501 P0C1 Predevelo edflow 1969 5.2035 1 . '.,� - 1970 4.9609 801 PO 1 Mitigated flow 1971 5.9389 1000 Trapezoidal Pond 1 ALL OUTLETS Mitigated 1972 5.5227 1001 Trapezoidal Pond 1 OUTLET 1 Mitigated 1002 Trapezoidal Pond 10 U T LE T 2 Mitigated 411 Datasets FlowtagP? PtPGIC I Evaa POC 1