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Home My WebLink AboutGRD2004-00004 Stormwater Plan - GRD Engineering / Geo-Tech Reports - 9/28/2004 SON_STA TF OT P C M o 7 A MASON COUNTY O ( T Z r2 N y „4 G) yin; oy PUBLIC WORKS DIRECTOR/COUNTY ROAD ENGINEER Oil 7864 Shehon,Washington 98584 INTER-DEPARTMENTAL COMMUNICATIONS DATE: September 28t", 2004 TO: Tami Griffey, DCD-Bldg Inspector Rick Mraz, DCD - Planner FROM: Alan A. Tahja, P/W - Co. Hydr. Engr. WO# BLD-04 SUBJ: Grading& Stormwater Plan Review NAME: Loudin/Chet's Trusses—Belfair GRD2004-00004 A Stormwater Site Plan prepared to comply with Ecology's 2001 Stormwater Management Manual for Western Washington requirements has been received and reviewed by Public Works.In the process of determining applicable standards to request conformance to,Marilou Pivirotto,Ecology's National Pollution Discharge Elimination System compliance official has been contacted who identified the industrial activity as needing an SSP which meets current Ecology standards. Attached please find a copy of the plan Mr. Chester Loudin delivered directly to Public Works for our review and comments. The plan shows existing as well as proposed improvements to the property,as well as proposed stormwater runoff control improvements. Public Works recommends acceptance of the SSP as satisfying County stormwater management requirements for the proposed site improvements. Public Works requests notification when the stormwater features are nearing completion so that conformance with the project designs can be verified. Please feel free to contact me at County extension 461 if you have any questions regarding these review comments,or if there are any other issues you feel need additional consideration. Sin erely, ,-- -7 Alan A. Tahja Enclosed: SSP prepared to meet WWHM2* requirements * Western Washington Hydrology Model 2 —"New Manual Requirements" .File: H: \WP\Strmvtr\Reviews\Chet's Trusses-2.doc vvvrv\(A) oats: uER - PUBLIC WORKS DEPT. � PERMIT#: I217�?(`�P� (E) Work Order Requested by: R2E_ 7 _ Number. Authorized by: Type of Work: Date: 10 Ir CH TB TO: R CE1� NAME AGENCY/COMPANY n BILLING ADDRESS PHONE )r P16' Wdflcs Person in Cha e: (C) Project Time Line. (from-to dates) o "O Pro)eCt start ante. �lo f TO s EsBmat Fkstsh Date; Awmdmate horn: `3.:� (!o ESTIMATED TOTAL i'S: (D) P3I4 Empbyee COST ESTIMATE � t Rate ou Subto<j( n e b-ll-off ,� zZ TOTAL s 9 t t 2 EQUIPMENT USED: TO_ T�is MATERIAL USED: -------------- bFIO�'1✓ uNZ'.\4JfM:ah.-Y�LVi4> •...... ..... .:. -pv-{.�-.>�•v- .wry ......v-. w.>....,.v..r..culY<:-ba.-.<aca;:�Tt`dHCL:%�i+`.:K'uQiai:i%+bB.Sw`':::�:ciNi.:;�;.':•V�:;'-:%�':-::=�:;^ `::a�;:?::::�:�::: DATE � PROJ�' S Flours ' � TOTAL$ -------------- EQUIPMENT USED: Pa Le at OT �J MATERIAL USED: AUt (G) BILLED DATE TOTAL ALL INy x_ PAID DATE r„ REC.f- _CIG#___ • ------ —J v.—aaa va l ava....Vavaaaa I-- _j V ... 1V1 1-1 VvwalaaVLLL VLlI (jt/V11J 11V111 Maintenance Field Monitoring Case Technical Technical Results Histories Bulletins Documents Download Vortechs®System Brochure View Vortechs@ System Animation Vortechs® System EPA award-winning design efficiently removes contaminated sediment, floating oil and debris from surface runoff. It is a compact, below grade system that is fabricated near the jobsite from precast concrete and marine grade aluminum. Its unique design allows for easy inspection and unobstructed maintenance access. Features include low capital cost per unit of treatment and a shallow excavation depth that reduces installation costs. The Vortechs® System's swirl-concentrator and flow-controls work together to prevent pollutant re-suspension and washout - even during high-intensity storm events. System performance has been documented with both laboratory and field data. Annual TSS removal efficiencies have been shown to be 80% for typical urban runoff particle distributions. Each system is custom-designed to suit site conditions and local regulatory requirements, treating design flows from 1.6 CFS to 25 CFS. Larger flows are treated using Vortechs Systems that are cast-in-place. on Bomb V" ~ tHlO Flaw Cw*91 Sears tint Chainber lover Flow Control Download more information: Maintenance High Groundwater Hydraulic Gradeline Vortechs® System Sizing The sizing chart below describes precast Vortechsa Systems and peak design flow rates treated by each. These models are sized to treat infrequent peak design flows (e.g. 10 year storms) without bypassing. Stormwater flows can also http://www.vortechnics.com/products/vortechsystem.html 9/7/2004 .._____ —.7---....aa..,-- ,,.....a ---..., --a uvaaa .�uaauv�.... 1 arF, G V1 J be treated using off-line (bypassed) VortechsO Systems or cast-in-place Vortechs Systems. Please refer to Technical Bulletin 3 for a complete explanation of our sizing criteria (or contact your local sales office for assistance.). Vortechs® Grit Peak Design Sediment Approx. Model Chamber Flow (A) Storage (B) Size (C) Diam./Area cfs. yds. L x W ft/ft2 ft. 1000 3/7 1.6 0.75 9 x 3 } C 6cfs 2000 4/13 2.8 1.25 10 x 4 3000 5/20 4.5 1.75 11 x 5 4000 6/28 6.0 2.5 12 x 6 5000 7/38 8.5 3.25 13 x 7 7000 8/50 11.0 4.0 14 x 8 9000 9/64 14.0 4.75 15 x 9 11000 10/79 17.5 5.5 16 x 10 16000 12/113 25.0 7.0 18 x LJ click here for metric conversion Engineering Notes: A) For on-line Vortechs® Systems without a bypass,sizing criteria Is based on providing one square foot of grit chamber surface area for each 100 gpm of peak design storm flow rate (e.g., 10-year storm). B)Sediment storage volumes assume a 3-foot sump and a 1-foot opening under baffle. C)The sizing information above is representative of typical Vortechs Systems. Construction details may vary depending on the specific application. Any alterations to the sizing chart specifications will appear on Vortechnics dimensional and shop drawings. Please contact Vortechnics for the weight of specific Vortechs) Systems if needed. Special Note: Oil storage capacity, when it is needed to meet a specific requirement for spill containment, can be sized to meet the storage requirement with the selected model. Vortechnics technical staff will optimize system geometry to meet containment requirements within a correctly size Vortechs® System. "When you are ready to specify a Vortechs System, please complete our Specifier's Worksheet and e-mail or fax to Vortechnics or contact a local Vortechnics Sales Office for assistance." Top I Related Sites leaf Notice I Privacy Policy http://www.vortechnies.com/products/vortechsystem.html 9/7/2004 WtSTERN WASHIVGTON HYDROLOGY MODEL V2 T PROJECT REPORT Project Name: Chet and Debbie Loudin Site Address: 1980 Old Belfair Highway City Belfair, WA 98528, (360) 275-7422 r -zap Report Date : 8/30/2004 Gage Quilcene Data Start 1955 Data End 1999 Precip Scale: 1.22 W&I.Cc 1, ,a. y ov PREDEVELOPED LAND USE Basin Basin 1 Flows To Point of Compliance GroundWater: No Land Use Acres TILL FOREST: 5.75 IMPERVIOUS: 0.71 DEVELOPED LAND USE Basin Basin 1 Flows To Pond 1 GroundWater: No Land Use Acres TILL FOREST: 0.79 TILL GRASS: 1 IMPERVIOUS: 4. 67 RCHRES (POND) INFORMATION Pond Name: Pond 1 Pond Type: Trapezoidal Pond Pond Flows to : Point of Compliance Pond Rain / Evap is not activated. Dimensions Depth: 7ft. Bottom Length: 134.12ft. Bottom Width 134.12ft. Side slope 1: 3 To 1 Side slope 2: 3 To 1 Side slope 3: 3 To 1 Side slope 4: 3 To 1 Volume at Riser Head: 3.202 acre-ft. Discharge Structure Riser Height: 6 ft. Riser Diameter: 18 in. NotchType Rectangular Notch Width : 0.057 ft. Notch Height: 2. 661 ft. Orifice 1 Diameter: 3.359 in. Elevation: 0 ft. V-4 T-T—A .. l ;— met i n (ji Ln (Jn (n (n AAjt, Ajpjp ,pJ�, 'AXA W W W W W W w W W W W W WNNNNNNNNNNNNNrrrrrrrrrrrrr000000000000 W NN3 :z, DOJJOICn (n :A WNNrOIDa) aDJOI (n (n :A W ;0 r DlOOJOJl L, :1 W Nrr0 i. W Nr00lDQ) JJOI (n :P W W Nr0 � MMFl W CnJONJA- MWr W (JtJON) X O. M MrW 0 --j0N AMM W (nJON AMMFD W CnJ0Nst:. MMr W LnJON4 O. 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I j w M W O J A r Co (n I j w a1 w O J (n NJ w 0, J N N N N N N N N N N N N N N N N N r r r r r r r r r r r r r r r r r r r r r r r r 0 0 0 0 0 0 0 0 0 0 0 0 0 0000 0 0 0 0 0 000 00 C D JJ Ol O1 Cn Cn �, �, �, W W NNr r O OD lD lD 0007 J JJ 1 ' (n U' (n ,p ,pW W W NN rrr O O ID I0 ID N N J �1 �j1 ) ) 6) Ln n (n :p ,p ,A W W NNNr r r 000 , Io CA r�A oD AID (nOU'nr0) r JNOD W ID rl0 Lnr JN000, I0 (nrJ W MJ, 0Ml j00 A06) N1D (nrJ W WMIQCD (nrJJ�. OJ W0a) W 1oM W <DM W 1D0) W> rN W -A Cn J ID N X�- J r �A CO N 01 r (n r O) N J AO J W r CO M -A N O W O> J J M M M J OD W O r W (n J lO N (n O> r (nW W JN JN JNOaA o f W O J (nN � rrrrr00o00000000000000000000000000000o000000000000000000000ID00000CD000 � r0000lDlDloNo 7 uNJJJJli >, >) > OIOI (nU'' U, C, CnU7 (n (n (n (, U, ,. :1, A, !A :A ,p ,p :I. i. i 11 :1 :1 W W W W W (, W W (, W NNNNNNNNrrrrO nNID0) W ON (nNIDJJ�- NIDJ (n W rIDJ (-nWrI0000.1 LnX, W NNr00W00 W JM01 (nJ�- W NNr0IDOJJOI (nJ�. W tJ0W MJdlC� W r 000a) tirOD n (n Ln In OI OD O N (n O N J N ODD W W W W w W .p m OD N 01 WN O> lD W mw W m> oN Cn Co W (n J l4r W (n Ol CO OOr F- F- o lO OD 0) .A r 07 .A W N Cn (n W J W > O O O O O O O O O O o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Co 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 > O O O o 0 0 0 0 0 0 0 0 0 0 0 0 0 0 O O O O O O O O O O O O O O O O O O O O O O O O O O O o O O O O O O O O O O O O O O O o O O O O o O o > O O 00 O O 00 O O O O O O O O O O O O O O O O O O O 00000 00 O O O O O O O O O O O O O O O o O O O O O O O O O O O O O O O O O 00 > 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C 0 5.678 0.649 2.991 1.249 0.000 5.756 0.653 3.041 1.281 0.000 5.833 0.657 3.092 1.314 0.000 5.911 0.660 3.143 1.347 0.000 5.989 0.664 3.195 1.380 0.000 6.067 0.668 3.247 1.641 0.000 6.144 0.671 3.299 2.196 0.000 6.222 0.675 3.351 2.929 0.000 6.300 0.679 3.404 3.803 0.000 6.378 0.682 3.457 4.800 0.000 6.456 0.686 3.510 5.904 0.000 6.533 0.690 3.563 7.106 0.000 6.611 0.693 3.617 8.400 0.000 6.689 0.697 3.671 9.778 0.000 6.767 0.701 3.726 11.24 0.000 6.844 0.705 3.780 12.77 0.000 6.922 0.708 3.835 14.38 0.000 7.000 0.712 3.890 16.05 0.000 ANALYSIS RESULTS Flow Frequency Return Periods for Predeveloped Return Period Flow(cfs) 2 year 1.057927 5 year 1 .502512 10 year 1.847047 25 year 2.343928 50 year 2.76178 100 year 3.223132 Flow Frequency Return Periods for Developed Mitigated Return Period Flow(cfs) 2 year 0.618091 5 year 0.870114 10 year 1.060132 25 year 1.327995 50 year 1.548653 100 year 1.788226 Yearly Peaks for Predeveloped and Developed-Mitigated Year Predeveloped Developed 1956 4.684 0.696 1957 0.971 0.878 1958 1.511 0.488 1959 1.612 1.232 1960 1.006 0.678 1961 1.280 0.497 1962 1.127 0.559 1963 0.995 0.861 1964 0.766 0.447 1965 0.506 0.440 1966 2.723 0.473 1967 1.145 1.090 1968 1.080 0.743 1969 0.872 0.526 1970 1.046 0.717 1971 1.494 0.523 1972 1.138 0.508 1973 1.083 0.522 1974 1.450 1.118 1975 1.166 0.462 1976 1.293 0.517 1977 0.813 0.509 1978 0.919 0.512 1982 0.959 0.437 1983 1.621 1.548 1984 0.591 0.359 1985 0.883 0.376 1986 0.942 0.773 1987 1.133 0.502 1988 0.848 0.602 1989 0.554 0.388 1990 0.717 0.574 1991 1.173 0.695 1992 1.043 1.160 1993 0.744 0.438 1994 1.736 1.493 1995 1.043 0.764 1996 1.247 0.910 1997 1.101 0.742 1998 0.988 0.717 1999 2.016 1.351 Ranked Yearly Peaks for Predeveloped and Developed-Mitigated Rank Predeveloped Developed 1 2.7232 1.4930 2 2.0157 1.3508 3 1.7359 1.2321 4 1.6210 1.1599 5 1.6120 1.1179 6 1.5106 1.0895 7 1.4936 0.9099 8 1.4504 0.8781 9 1.2932 0.8611 10 1.2800 0.7734 11 1.2467 0.7643 12 1.1732 0.7425 13 1.1656 0.7423 14 1.1447 0.7170 15 1.1385 0.7169 16 1.1330 0.6960 17 1.1265 0.6952 18 1.1090 0.6782 19 1.1008 0.6322 20 1.0826 0.6016 21 1.0795 0.5741 22 1.0459 0.5592 23 1.0434 0.5263 24 1.0428 0.5230 25 1.0055 0.5222 26 0.9954 0.5165 27 0.9875 0.5117 28 0.9714 0.5086 29 0.9591 0.5077 30 0.9416 0.5017 31 0.9188 0.4974 32 0.8963 0.4883 33 0.8828 0.4734 34 0. 8815 0.4647 35 0.8724 0.4621 36 0.8481 0.4470 37 0.8125 0.4403 38 0.7660 0.4382 39 0.7437 0.4373 40 0.7170 0.4319 41 0.5913 0.3879 42 0.5538 0.3758 43 0.5056 0.3591 1/2 2 year to 50 year Flow(CFS) Predev Final Percentage Pass/Fail J N N N N N N H H 1- 1-+ H H H H H F-+ H H H H H H H H H H H ,--+ H H F- H H H H H H H H H H H H F--+ H H O O O O O O 0 O O O O O O O O O O O OOOOIO IO tO ID IO OD OO OJ ODJJJJJOl 616161 Cn (.n (}i (n ,p �p ,p �p i. W W W W OO O Io IO Io to 0o Oo �I J J J Jp1 n W OwmJI AH IOJ0. N000Ul WHlDmXX NOJCnWF-+ WM ,pN (pJ (nW C) WM AHtp --] U r\) 0W I W IpJ .PNC> W0 W h- WMJ�,. NiDJUiW 0Wa) A1--+ 1D J0J (JtN0 -IU'tNlp j C1 NlOJ .AN) DoM AH1p61lAF lwC) WHODOIW HODOI W OOOUt (Ai OOJ (,n WOJUINOJU', NOJ .PNIOJXANIOJ .PHIp (:Y) Cp. toC) J W JNO) LTI0 AOOW JNd> H (nO .PIO W ODNO) HUl0JA- W WODNJHOIO ()IW W OUN JH0I0 (nl0XAO7 W JF dM0Ul (OlAOD WJNOlHU7 (O .pOo W JN6) JNNNNNN W W W W W W W W W pLnUiol0) M0) mO wl of pHHHHHHHNNNN W W W W J'A (n (JtaIOIOOIOFl HHHNNNW W J�- �AUi61JJOOHHH OF A (nO) Oo00O0H .AOH (np) NOOlW W W 0011 W 0 W OJ�.. JO (nF dM WN0WW0H W H H M W kA �A 0 OD N O W W N (n 0 O N 0 DOC 0 0 0 0 0 O O O O O O O O O O O O O O O O O O O O O O O O N N N N W W P J p H H H N N W A U 101 a u l p H H H H H H H N N N W W ,A 4�. O O l J l O AJIO (ntOUINHMH (nHN W j�:. 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O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O O � rororororororororororororororororororororororororororororororo w a a w w a a a a a w v w a v a a v v w a a w w a w a v a a w ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro ro to ro ro ro ro ro ro ro ro It Fd ro ro ro ro ro ro ro m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m (n m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m m (n m m m m m m m m m m m m m m 2.210b 2 0 .0 Pass 2.2430 2 0 .0 Pass 2.2656 2 0 .0 Pass 2.2882 2 0 .0 Pass 2.3107 2 0 .0 Pass 2.3333 2 0 .0 Pass 2.3558 2 0 .0 Pass 2.3784 2 0 .0 Pass 2.4009 2 0 .0 Pass 2.4235 2 0 .0 Pass 2.4460 2 0 .0 Pass 2.4686 2 0 .0 Pass 2.4911 2 0 .0 Pass 2.5137 2 0 .0 Pass 2.5362 2 0 .0 Pass 2.5588 2 0 .0 Pass 2.5814 2 0 .0 Pass 2.6039 2 0 .0 Pass 2.6265 2 0 .0 Pass 2.6490 2 0 .0 Pass 2.6716 2 0 .0 Pass 2.6941 2 0 .0 Pass 2.7167 2 0 .0 Pass 2.7392 1 0 .0 Pass 2.7618 1 0 .0 Pass Water Quality EMP Floor and Volume. On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. program and accompanying documentation as provided 'as-is' without warranty of any kind. The entire risk regarding the performance and results of this program is assumed by the user. AQUA TERRA Consultants 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 AQUA TERRA Consultants 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 user of, or inability to use this program even if AQUA TERRA Consultants or the Washington State Department of Ecology has been advised of the possibility of such damages. YEAR FLOW(Cft 100 3.223 11110 50 2.762 1.0 00.0poo dOkkkk 25 2,344 00.04 X)K 10 1.847 --T o Prudeveloped 10E4 x Developed Mitigated 5 1.503 2 9.058 lift, 1 10 20 30 40 50 60 70 80 90 99 10E-2 V Cumulative Probability Yearly Peaks for Predeveloped Flow Frequency Chart YEAR FLOW(Cfs) 2.76 2.20 x Developed ovil)Facility Caf/ ----- - -- -- 1.65 0.53 C � { y ! j! t i 10E-5 10E-4 1 DE-3 10E-2 110E.1 1' 10 Percent Exceeding Yearly Peaks for developed W/O Pond Duration Graph YC AR FLOP)left) 100 1.788 50 1.549 � I ► I. 25 1.328 10 1.060 2 .6181 Yearly Peaks for Developed W/Pond 0.9 0.676 ci 0.451 - --- --- — -- - - - --- C 0.225 _ 0.000 - 1955 1966 1977 1988 1999 Yearly MaxlPeak Values for Precip Gage 1 Quilcene 0.902 0.676 [r s 0.451 4 ` 0.225 0.000 1955/10/01 1966/09/30 1977/09/30 1988/09/29 1999/09/31 Hourly Max/Peak Values for Precip Gage 1 Quilcene 1.734 1.300 -- L.I._ (� 0.867 -- ------ —- - -- - _C3 LL 0.433 0.000 . 1955 1966 1977 1988 1999 Yearly Max/Peak Values for Pond 1 Volume data Developed Mitigated Section II-Erosion and Sediment Control Plans e. Provide details for bypassing off-site runoff around disturbed areas: Refer Construction Stormwater Pollution Prevention Plan Checklist to the drainage ditch at the base of the 50 to 70%embankment located in the upper 1. General center of the property. Section I-Construction SWPPP Narrative,continued: f. Indicate location and outlets of any dewatering systems: Not applicable, a. Vicinity Map: Refer to engineering drawing 1 of 2 6. Soils: Decription of on-site soils b. City of Belfair Clearing and Grading Approval Block: Refert to the top of engineering 4. Location of Detension Bi a. Soil Name(s): Sandy sift with some gravels drawing 1 of 2 a. Identify location of detention Bli Hydroseeding and/or mulching held in place b. Soil Mapping unit: Brown sandy silt with some gravels c. Erosion and Sediment Control Notes: Refer to engineering drawing 1 of 2 which contains with hemp netting will be installed on the 50 to 70%embankment located at the upper c. Erodibility: Low,as long as disturbed soils get compacted the 12 required elements for the Construction Stormwater Pollution Prevention Plan center of the property. d. Settleability: Low,as long as disturbed soils get compacted e. Permeability: Sandy silty soils provide moderate permeability 2. Site Plan 5. Erosion and Sediment Control Facilities f. Depth: Sandy silty soils goes down 4 to 6+feet a. Legal description of suject property: SE 114 of the SE 114 of Section 17 T23N R1 W WM a. Show the locations of sediment trap(s),pond(s),pipes and structures: Refer to g. Texture: Brown sandy silt b. North Arrow: Refer to Sheet 1 of 2 drawing 1 of 2 for the location of the catchbasins,sedimentation pond,and drainage h. Soil Structure: Mostly sandy silty with gravels c. Indicate boundaries of existing vegetation,e.g.tree lines,pasture areas,etc: Refer to ditches which collect sediment. Sheet 1 of 2 b. Dimension pond berm widths and inside and outside pond slopes: Refer to 7. Erosion Problem Areas d. Identify and label areas of potential erosion problems: Potential soil erosion control drawing 1 of 2. Description of potential erosion porblems on site: Hydroseeding problems can occur on the 50 to 70%embankment located on the left side of the road leading c. Indicate the trap/pond storage required and the depth,length,and width and mulching held in place with hemp netting is recommended on 50 up to the 24'x 36'residence at elevation 104'. dimensions: Refer to drawing 1 of 2 for sedimentation pond details. to 70%slope embankment on the east side of the proposed paving e. Identify any on-site or adjacent critical areas and associated buffers: Awetland area d. Provide typical section views through pond and outset structure: The pond area. has been identified on the south side of the sedimentation pond with a 25'setback as shown has a 3:1(V:H)sides slopes with a 6'riser for outlet control to the drainage ditch on drawing 1 of 2 and is labeled as a drainage ditch(swale). leading to the Union River. 8. Construction Phasing f. Identify FEMA base flood boundaries and Shoreline Management boundaries(if e. Provide typical details of gravel cone and standpipe,and/or other filtering a. Construction sequence: Initially,the area to be paved will be applicable: This is not applicable to this property. devices: Not applicable since there are no currently existing catchbasins to grubbed and Geared. Then,the culverts and catchbasins will be g. Show existing and proposed contours: Refer to drawing 1 of 2 for the elevation contours. protect from sedimentation. installed per the engineer's drawings. The existing 50'x 100' The final elevation contours do not vary significantly from the existing elevation contours since f. Detail stabilization techniques for outlet: A combination of a standard weir sedimentation pond will then be enlarged to 100'x 200'as shown there will be very little excavation work for the planned asphalt surfacing. and orifice as called out in the engineering computer simulation will provide outlet in the engineer's drawing. The existing Peninsula Truss Co.building h. Indicate drainage basins and direction of now for individual drainage areas: Elevation control from the sedimentation pond. will be enlarged from 50'x 100'to 50'x 200'as shown on the drawing contours 84'to 97'outline the main drainage basin for the area. The 100'x 200' x 7 sedimentation g. Detail control/restrictor device location and details: Outlet control from the on sheet 1 of 2. pond has been designed to handle the surface water runoff from this basin which includes part of 100'x 200'x 7 deep sedimentation pond will provided by a 6'high, 18"diameter b. Construction phasing: Will occur per the construction sequence the Old Belfair Highway. riser with the location shown in drawing 1 of 2 with a 0.057'wide by 2.661'deep above. I. Label final grade contours and identify developed condition drainage basins: Refer to rectangular weir at the top of the riser and a 3.359"diameter orifice at the bottom drawing 1 of 2. of the orifice. 9. Construction Schedule j. Delineate areas that are to be cleared and graded: Refer to the blue areas on drawing 1 of 2. h. Specify mulch and/or recommended cover of berm and slopes: Hydroseeding 1. Provide a proposed construction schedule: It is anticipated that k. Show all cut and fill slopes indicating top and bottom of slope catch lines. The bottom of and/or mulching will protect the 50 to 70%bare embankments and also the sides of construction will start once a building permit has been issued for the the 50 to 70%sloped embankment is shown in drawing 1 of 2 as log ated on the west side of the the 100'x 200'x 7 sedimentation pond. project. It is recommended that construction occur during the drier ramped road going up to the 24'x 36'residence at the top of the hill. i. Provide rock specifications and detail for rock check dam(s),if applicable: times of the year from early June through October. Not applicable on this project. II. Proposed wet season construction restraints for environmentally 3. Conveyance Systems j. Specify spacing for rock check dams as required: Not applicable since the sensitive critical areas: During periods of continuous rainfall greater drainage ditches are already lined with natural vegetation. than 1"during a 24 hour period,it is recommended that any disturbed a. Designate locations for swales,interceptor trenches,or ditches: Refer to drawing 1 of 2 k. Provide front and side sections of typical rock check dams: Not applicable areas be covered with clear 6 mil visqueen to protect soils especially b. Show all temporary and permanent drainage pipes,ditches,or cut-off trenches required on this project. on the steep bare embankments from soil erosion and slides. for erosion and sediment control: Refer to the ditches shown in green on drawing 1 of 2 to I. Indicate the locations and provide details and specifications for silt fabric: provide erasion and sediment control. Standard WSDOT siltation fencing shall be installed at the base of the 50 to 70% 10. Financial/Ownership Responsibilities c. Provide minimum slope and cover for all temporary pipes and call out pipe inverts: No embankment at the upper center of the property and also on the downhill side of a. Identify the property owner responsible for the initiation of bonds temporary pipes will be required on this project. all paving areas to prevent sediment from flowing into state waters. and/or other financial securities: Chet and Debbie Loudin. d,Show grades,dimensions,and direction of flow in all ditches,swales,culverts,and pipes: m. Locate the construction entrance and provide detail: Existing entrances to b. Describe bonds and/or other evidence of financial reponsibility Refer to the following Table. the project are already in place for the current truss manufacturing facility access. for liability associated with erosion and sedimentation impacts: No new construction entrances are planned for this project. It is anticipated that Chet and Debbie Loudin,the property owners will provide evidence of financial responsibility. -- 6. Detailed Drawings: An oiUwater separator vault has been incorporated into the Erosion and Sediment control plan and will provide oil/water/sediment separation just 11. Engineering Calculations: Stormwater catchbasin,pipe sizing,and grade prior to entering the sedimentation pond as shown in drawing 1 of 2. It is recommended 1. Provide Design Calculations: that a Vortech(or equivalent)oil/water separation system be installed with a 6-month a. Sediment Ponds/Traps: Refer to the attached WWHM2 computer returning interval storm event and resulting in a flow of 270 gallons per minute or 0.6 simulation results which shows that a 109 x 2D0'x 7'deep Catchbasin cubic feet per second. This engineer is in the process of submitting detailed specifications sedimentation pond is adequate. to Vortec at wwv.vortechnics.comJspecifiers/vor for the detailed design drawings. b. Diversions: No diversions are planned for this project Flow direction Diameter i N Type I c. Waterways: No waterways are planned for this project. (ref.Note 1) Grade o 7. Other Pollutant Bi Additional BMPs may be required such as a rock check dams d. Runoff/Stormwater Detention Calculations: Refer to the A to B 12, WSDOT Type 1 3% in the overflow drainage channels located at the base of the embankment. This engineer attached WWHM2 computer simulation results which shows that a B to G 24" 2% shall be called out to the project site during construction on a montly basis during the 100'x 200'x T deep stormwater detention pond is adequate. C to G 24" 5% work and prepare a written status report of the work performed and any"as builts drawings" G to H 301, " 4% as a result of this onsite monitoring. D to E 12'' 3% E to H 18" 1% 8. Monitoring Locations: The upstream water sampling location will be at the 19'culvert F to 1 12" 5% inlet just on the north side of the 49 x 80'storage building. The downstream monitoring I to H 181, 2% station will located at the point where the drainage ditch from the 100'x 200'sedimentation J to H 18.1 4% pond flows into to the Union River. Kto L 16, 1% Note 1: Install a drop inverted"T'to remove oil and sediment. Requires inspection and cleaning bi-montly during winter 1! 14 p EROSION AND SEDIMENT CONTROL PLAN-NOTES and spring months. ��J * Q for Peninsula Truss Company, 1980 Old Belfair Hwy N A,y��c 9 Belfair,WA(Parcel#12317-41-00060) 0 Prepared for Chet and Debbie Loudin PO.Box 2326 Belfair,WA98528 _--- -. (360)275-7422 Prepared by: Marta Engineering and Testing A 30758 PO.Box250,Ocean Shores,WA98569 �O (if Al- (800)590-0958,(360)289-9682 fax Al-�G` _ - Sept.7,2004 -T— Designed by: SPM Sheet 2 of 2 N 1980 NE Old b. Description of Existing Vegetation,cont'd: Douglas firs,Cedars, Belfair Hwy Qo W_i _ E Mas on County Clearing and Approval Block and ground cover most of the east third of the property as shown in the do engineering drawing. This will be left all natural by the property owners. a� 92.8'El.at 18"invert. Reviewed by: c. Description of Existing Drainage: A 12'diameter culvert under the S Old Belfair Highway located just outside the northwest corner of the Existing 18"dia. Approved by. property and then connects to the county's 24"culvert which then goes �T county culvert Drainage ditch(Swale) g property and then the ; nh' into a drainage ditch on the north side of the o to handle overflow conditions fl dit Date: surface water runoff flows into an 18"diameter culvert which runs down from the 24'culvert during the middle of the property from the north to south as shown in the drawing. heavy,continuous rainfall Note: Clearing and grading limits are shown in light blue Finally,the surface water runoff flows into an existing 50'x 100' / 12"dia.culvert +5 0 \ ;; Existing drainage in the drawing below sedimentation pond before flowing into a naturally vegetated drainage VICINITY MAP NTS �Q e.acr,-r 6w sq _ ditdt(Swale) - ditch leading to the Union River. Paved neigborhood with several ( G� paved area ` parked vehicles on this side of the 1� �t �yfef - - rn )scent Areas Q� - - Parcel#12317-41-00050 a. Ad' roadway.(Contributes to surface FP. A ro`.' r"� B C 90 I. Description of adjacent areas which may be affected by water runoff.) �12'dia ■ - 40 x 80 a Proposed drainfield Proposed drairrfield l:- X 119 B. It site disturbance: `p r� _ ' a storage Bldg QnIG location _ _ k�catiort_ - _ a. Streams: The Union River is located at the southeast a- -"- ---- _ 88. comer of the property and an unnamed creek is located Y / • - � i _ Pr etfdrafnfield easement _ outside the west end of the property that flows under the or' P e 2Id trees� ' G X 10S EI. - - -- Old Belfair Highway. X-yearo: X 96 B. F vveu(s5'a � i This creek has overflowed e yc✓� X97.1 EL- _ 54,700 *� X87.8'El. X 87.9 El. b. Lakes: There are no lakes in the vicinity of the property. v� D 17 dia.PVC E " raved area X 104'El. �2ia y This area to be left all natural c. Wetlands: Wetlands are located on the south side of toward the 12'culvert pipe __ aF- ------ ---- a _ t o �pJ the property along the drainage ditch swale as shown in during the winter and spring X 92 3 Ei. X 90.6 El. ; consisting of trees and meadow the drawing, Appropriate setbacks have been provided months. - X 93.T El. a AP a / for the location oft e expanded sedimentation pond, ' i 87 d Residential Areas: The main residential is located on ----------------`d� X96 Parcel ` ;;.D ;�.._ � -_ - - G� an elevated plateau and is not affected by the asphalted I lip+toy d Peninsula X .6 E�w x 1o0' n X 91. _ ----- _ X 86.5' surfacing project A24'x 36'house is located at the Truss Company addition (� northwest corner of the propEfty but will be removed X89i9 EL, " -- pt 9`da , „ i 1a_--- - X 8T El. during the paving operations. A 12'x 57'trailer will remain drainfield 4--- ------- -- --------------------- -fir'' - __ - located at the west end of the property and is also not 0' 100' ��yWy - X 9A.7 EC300 500 - 1yryy�y affected by the paving work �-`-------------J------ y - -------- i--�-- -� -'�--- -- - 1----------------�- - - ----J----------------'L----------------L---------_-----J--- -- . - -- 5(q� --- e. Roads: The Old Belfair Highway runs from the southwest El. -X 9E)Et.-- 9T _ Drainage ditch(swale) X 86.6'El. ,- X 85.3'El. to the northeast direction at the outside NW corner of the 96 95' 94� 93 _ �a a ter separ or X 86.7 El. property as shown. A 12'diameter culvert under the for 6 month storm 11 Install 2'dia.pipe - T X 88,". 'Phis area to be left all natural highway helps to drain water off the highway and from the X 90.$El. '�E89'-El - -270 =0.6 cfs to proposed drainfield 91' - - -'- consisting oftrees and meadow unnamed creek located outside the wrest end of the 8"dia.culvertproperty. at NE corner of property ---y'- , 1 Parcel#12317 41-00070 -.-- -22,5W sq.ft. d 100 x 200'x T settling pond from 6'high x 18"dia. f. Other: A 50'x 100' truss manufacturing facility will be gD�` paved area with 11 V.H side slope -- riser in settlingpond. expanded to 50'x 200'with new asphalt surfacing Existing 12'dia ' ( ) Pe I Existing -. Po P P 9 culvert to be (future) X 88.4 El (refer to attached VVWHM2 5a x 10i7 X r 5"EI X 86'EI around the building as shown. A 40'x 80'storage removed X 89.4 e-,' simulation results) settling building is located on the north side of the property with v-- UNION RIVER pond the 19'culvert running underneath it. `i 89 200 (perimeter) II. Description of the downstream drainage path leading from the site Install 12"dia, f26 rometbackd Sand -- - to the receiving body of water. (Minimum distance of 400 yards.) -- - 3E88'EI.. __-X-gg El, X 88.6-El. bar./ During heavyrainfall the surface water runoff flows into a 1 00'x 200'x T culvert for storm 64'EI. 9 sewer 88, ___.----- sedimentation pond and then into a 6'high standpipe which leads to Drainage.ditch(sVwale) -- natural vegetated drainage ditch where the surface water runoff is 2. Project Description further filtered before it flows into the Union River. The vegetated 87' 12 Required Elements for the Construction Stormwater Pollution Prevention Plan a. Total Project Area: 5.75 acres drainage ditch acts as a biofiltration facility that runs nearly 300'before 8C, b. Total proposed impervious area:4.67 acres flowing to the river. 1. Mark Clearing Ltfnits: Response: Clearing limits are identified in the above drawing c. Total area to be disturbed: 4.48 acres 5. Critical Areas DESIGN GUIDELINES and will be marked by survey stakes`prior to construction. a. Description of critical areas that are on or adjacent to the site: 2. Establish Construction Access: Response: Main construction access is already in Existing Site Conditions A relativlely steep embankment is located on the east side of the August 2001 Stormwater Management Manual for Western Washington,August 2001 place and is located on the south side of the existing Peninsula Truss building. proposed paving area that will need to be protected from slides and POND SIZING 3. Control Flow Rates: Response: Refer to the attached Western Washington Hydrological a. Description of the existing topography:The soil erosicn during heavy extended rainfall periods. An unnamed Model II computer simulation results for this basin which automatically sizes the retention general area of the expansion of the paving is located at the outside west end of the property which flows under Computer simulation: Western Washington Hydrological Model version 2 WVVHM2 pond using actual rainfall data starting in 1955 to 1999. It is recommended that construction is relatively level ground with a difference in 9t ( ) the Old Belfair Highway but is not affected by the proposed paving with continuous simulation hydrology(HSPF). Predeveloped input(Mason County at takes place during the drier months of the year from June through October to minimize elevation of about 13'with an elevation of 96.3' project. 1980 Old Belfair :Till forest=5.75 acres,impervious surface=0 71 acres from surface water runoff during construction. on the north side of the property to 83.5 on the Hwy): Pe - ( Hwy), b. Description of special requirements for working in or near critical Post developed input:Till forest=0.79 acres,till grass-1 acre,impervious area roc 4. Install Sediment Controls: Response: All bare soil areas will be covered with visqueen south side of the property. The residence lies o P P 9 - Pe ( = areas: The recommended BMPs for stabilizing the 60 to 70/o 0.32 acres,streets,sidewalk,parking 3.85 acres, rid=0.5 acres. Refer to drawin at the end of each days work during periods of rainfall greater than 1"in a 24 hour periods. on a plateau at an elevation of 104'as shown pa g= pond ( g above for details on impervious areas.) Also,bare soils will be immediately protected if this rainfall occurs during the day and soil in the drawing. An embankment at 118'elev. embankment is hydroseeding, mulching,and/or the use of biodegradablehemp netting to help hold the mulch inplace and to prevent slides and disturbing work will need to stop during this time, lies in the upper mid-section of the property. Auto and sizing: Bottom length x bottom width=134.12'x 134.12'=17,990 ft. 5. Stabilize Soils: Response: All exposed soils especially on sloped embankments shall b. Description of existing vegetation: A 300' soil erosion from taking place during heavy rainfall which can be as much P g: gt sq Actual pond sizing:98'x 198'=19,400 sq ft. >17,990 sq.ft.(req'd) OK be protected by hydroseeding and/or mulching to prevent soil erosion and slides on the long x 20'wide greenbelt consisting of deciduous as 8 inche3 in a 24 hr period for the 100 year rainfall. steep embankments. trees will be preserved running from east to west 6. Protect slopes: Response: Apply hydroseeding,mulching,and/or visqueen held inplace as shown in the drawing. with sandbags to help protect the slopes along the embankments especially during periods CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN CHECKLIST g P P � g � y �� AN Reference: August 2001 Stormwater Management Manual for Western Washington) of continuous rainfall,i.e., 1"or greater of rainfall in a 24 hour period. P. Q EROSION AND SEDIMENT CONTROL PLAN ( J 9 9 ) �FN � 7. Protect Drain Inlets: Response: Currently there are no drain inlets or catchbasins on the � � � - for Peninsula Truss Company, 1980 Old Belfair Hwy 1. Construction Stormwater Pollution Prevention Elements site to protect. 5� OF W. SX l9 O Belfair,WA(Parcel#12317-41-00060) a. Describe how each of the Construction SWPPP elements has been addressed 8. Stabilize Channels and Outlets: Response: An existing sedimentation pond and drainage �`o Q - ------ - - -- - ditch swales revert surface water runoff from flown direct) into the Union River. F Prepared for: Chet and Debbie Loudin through the Construction SWPPP Answer: Refer to the following 12 elements.. P g y O PO.box 2326 b. Identify the type and location of Best Management Practices used to satisfy the 9. Control Pollutants: Response: Construction equipment shall be inspected for any oil or required element. Answer: Refer to the detailed diagram above the type and hydraulic leaks and be properly maintained prior to arrival on site j Belfair,WA 98528 locations of the applicable BMPs. 10. Control De-Watering: Response: De-watering is not required since the groundwater table r� l (360)275-7422 C. Written justification identifying the reason an element is not a icable to the proposal. is located below the bottom of the catchbasins. - Prepared by: Morta Engineering and Testing J fY 9 PP Pr Pce A Answer:Refer to the following 12 elements. ros e ma especially 11. Maintain BMPs: Response: Hydeeding and mulching will be P.O.Box 250,Ocean Shores,WA 98569 `�' 30758 during periods of heavy extended rainfall periods. Off, LIST ER (800)590-0958,(360)289-9682 fax 12. Manage the Project: Response: The owner will be responsible for managing this project S SIQIVALE'11 - and ensuring that the Construction Stormwater Pollution Prevention Plan is properly and Sept 7 2004 Designed by: SPM Sheet 1 of 2 thorou hl im tented er this construction SWPPP. FxPiaFt / 1980 NE701d4� If Belfair gA ------ b. Description of Existing Vegetation,cont'd: Douglas firs,Cedars, ------ E Mason County Clearing and Approval Block and ground cover most of the east third of the pr operty perty as shown in the r 92.8'El.at 18"invert --- ---- __ _ _ __ engineering drawing. This will be left all natural by the property owners. Reviewed by: %• S % c. Description of Existing Drainage: A 12'diameter culvert under the �Y I Old Belfair Highway located just outside the northwest corner of the ApprExisting 18 dia. C3NZN Drainage ditch svrale} °V�by property and then connects to the coo nty's 24"culvert which then goes county culvert a9 ( to handle overflow conditions Date: into a drainage ditch on the north side of the o�Q pr perry and then the from the 24"culvert during surface water runoff flows into an 18"diameter culvert which runs down heavy,continuous rainfall� ; `�-; �� a the middle of the property from the north to south as shown in the drawing. L,, eri Existing drainage / Note: Clearing and grading limits are shown in light blue Finally,the surface water runoff flows into an existing 59 x 100' V I M 12'dia.culvert in the drawing below sedimentation pond before flown into a natural) v r1Q 7680 sq. TM ditcri(swale) / _ rig y vegetated drainage Paved neigborhood with several �� ` paved area�� - J ditch leading to the Union River. parked vehicles on this side of the 0 if a rn roadway.(Contributes to surface �� )' - ---- �' -- �. Adjacent Areas water runoff.) ��P', + o A " i, _ 1� C Parcel#12317-41-0005D 9 j 4Q�{ ` X 118'EI. Proposed drainfield Pr ,-" W 1. Description of adjacent areas which may be affected by at a�e bl ig' A G 4�- " d drainfield,_ location - `"-g the site disturbance: I _ __--- _;__ l __`_-_- _- a. Streams: The Union River is located at the southeast • - __ comer of the property and an unnamed creek is located �o, deep een - esenve at old trees � - ti dralnfield easement - - outside the west end of the property that flows under the X 97 1 EL, X s0.6 EL �+ C' X.95'Ell Well 85'd X 105 Ej• - _. F ( ) Old Belfair Highway.This creek has overflowed ;i- , �' * `X'87•6 El. X 87.8'El. b. Lakes: There are no lakes in the vicinity of the property. toward the 12'culvert / arm _, y X 104 a. ZA y' c• Wetlands: Wetlands are located on the south side of during the winter and spring / `--"1Z' --- j P ¢ This area to be left all natural the o along the drainage months. X 923 I. X 9t1.6 El. ;; X 93.P E � , � consisti of trees a property n9 ditch swale as shown in I rig rid meadow the drawing. Appropriate setbacks have been provided t for a location oft e expanded sedimentation pond, d► - _ '� d. Residential Areas: The main residential is located on 14e- Peninsula u ' -----X 6 EI 50'x 100 ; ,, X _ - ' ,- X 86 5 EI - an elevated plateau and is not affected by the asphalted Parcel#12317�1-00060 87' •��, Truss Company u� - ----- X8T�1 surfacing project. A 24'x 36'h addition � n '�'� n9 Pr j Dose is located at the �;g �g '.' northwest corner of the propely but will be removed -- x 100r - ,-' . litCY ----- - ----------X- _ during un t he X 9A.7 L7300 ------ - - _ a(8T _ located at he west eend of the property and is alsolln ma ir ---- , - - - �- --, --- - -- ------- -F----------- - - - 7 900' affected by the paving work . � ��. 915, 95 9dr 93 E1r X E}------------------ -'' : ---------- ----- ---------'--- e. Roads: The Old Belfair Highway runs from the southwest Drainage ditch(Swale) X 86.6'El. - X 85.3'B. to the northeast direction at the outside NW corner of the 9z ----- -- ,-.- 7 �,a,-'' a ersepar ,.' ,- Install 2'dia.pipe "- -'' 4- for 6 month storm '� X 86.2 property as shown. A 12'diameter culvert under the X�•9�. '�E89 EJ -- `R to p roposed drainfietd g1, 0m-_ ''X 88, EI. This area to be left all natural highwayhelps to drain water off the highwayand from the i - Z7 at NE corner of property % -- - 0.6 c i consisting of trees and meadow unnamed creek located outside the wrest end of the 18"dia.culvert ------ sq.ft 6 100'x 200'x 7'settling pctj- from i high x 18 dia Parcel#12317 41 00070 propel' Existing12'dia; �` Pied with 3:1(V H)side slope ) -'""--l-tiserin settling pond. _ n9 ltY Other: A 50'x 100' truss manufacture facility will be culvert to be (fie) X 88 4'EI (refer to attached WVVHfJ12 '� �� expanded to 59 x 2OU with new asphalt surfacing removed / X 89.4'a, g simulation results) 1 r, --------X 86'El. \ around the building as shown. A 49 x 89 storage ---------_- building is located on the north side of the property with ' ' UNION RNER the 18"culvert running underneath it. i 89' 20i7 rimeter _ if. Description of the downstream drainage path leading from the site Installl2'dia' p g �� _ t-'L= r from�we-land ba7 to the receiving body of water. (Minimum distance of 400 yards.) culvert for storm __ -�---"-�_-- X88'EI. X88:5_EL-� y sewer _ ___ ,_--" -.- � During heavy rainfall the surface water runoff flows into a 100'x 200'x T -"^--' Drain editotr --- _ _ sedimentation pond and then into a 6'high standpipe which leads to ag (Swale) natural vegetated drainage ditch where the surface water runoff is 87' 2. Project Description further filtered before ft flows into the Union River. The vegetated 86 12 Required Elements for the Construction Stormwater Pollution Prevention Plan a Total Project Area: 5.75 acres drainage ditch acts as a biofiltration facility that runs nearly 30O'before b. Total proposed impervious area:4.67 acres flawing to the river. 1. Mark Clearing Lgatts: Response: Clearing limits are identified in the above drawing c. Total area to be disturbed: 4.48 acres DESIGN GUIDELINES and will be marked by survey stake§$hor to construction. 5. Critical Areas 2. Establish Construction Access: Response: Main construction access is already in Existing Site Conditions a. Description of critical areas that are on or adjacent to the site: August 2001 Stormwater Management Manual for Western Washington,August 2001 place and is located on the south side of the existing Peninsula Truss building. A relativlely steep embankment is located on the east side of the POND SIZING 3. Control Flow Rates: Response: Refer to the attached Western Washington Hydrological a. Description of the existing topography:The proposed paving area that will need to be protected from slides and Model I I computer simulation results for this basin which automatically sizes the retention general area of the expansion of the paving soil erosion during heavy extended rainfall periods. An unnamed Computer simulation: Western Washington Hydrological Model version 2(W1MiM2) pond using actual rainfall data starting in 1955 to 1999. It is recommended that coristruction is relatively level ground with a difference in is located at the outside west end of the property which flows under with continuous simulation hydrology(HSPF). Predeveloped input(Mason County at takes place during the drier months of the year from June through October to minimize elevation of about 13 with an elevation of 96.3' the Old Belfair Highway but is not affected by the proposed paving 1980 Old Belfair Hwy):Till forest=5.75 acres,impervious surface=0,71 acres(from May), surface water runoff during construction, on the north side of the property to 83.5 on the project Post developed input:Till forest=0.79 acres,till grass=1 acre,impervious area(roof)= 4. Install Sediment Controls: Response: All bare soil areas will be covered with visqueen south side of the property. The residence lies b. Description of special requirements for working in or near critical 0.32 acres,streets,sidewalk,parking=3.85 acres,pond=0.5 acres.(Refer to drawing at the end of each day's work during periods of rainfall greater than T'in a 24 hour periods, on a plateau at an elevation of 104'as shown areas: The recommended BMPs.for stabilizing thq 60 to 70% above for details on impervious areas.) Also,bare soils will be immediately protected if this rainfall occurs during the day and soil in the drawing. An embankment at 118'elev embankment is hydroseeding,mulching,and/or the use of biodegradable disturbing work will need to stop during this time. lies in the upper mid-section of the property. hemp netting to help hold the mulch inplace and to prevent slides and Auto pond sizing: Bottom length x bottom width=134.12'x 134.12=17,990 sq ft. 5. Stabilize Soils: Response: All exposed soils especially on sloped embankments shall b. Description of existing vegetation: A 300' soil erosion from taidng place during heavy rainfall which can be as much Actual pond sizing:98'x 198'=19,400 sq.ft.>17,990 sq.ft.(req'd) OK be protected by hydroseeding and/or mulching to prevent soil erosion ans slides on the long x 20'wide greenbelt consisting of deciduous as 8 inches in a 24 hr period for the 100 year rainfall. steep embankments, trees will be preserved running from east to west 6. Protect slopes: Response: Apply hydroseeding,mulching,and/or visqueen held inplace as shown in the drawing. CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN CHECKLIST Mh sandbags to help protect the slopes along the embankments especially during periods (Reference: August 2001 Stormwater Management Manual for Western Washington) of continuous rainfall,i.e., 1"or greater of rainfall in a 24 hour period. 7. Protect Drain Inlets: Response: Currently there are no drain inlets or catchbasins on the EN P. 3Q*4 EROSION AND SEDIMENT CONTROL PLAN 1. Construction Stormwater Pollution Prevention Elements site to protect. �w WAS ��0 - for Peninsula Truss Company,1980 Old Belfair Hwy a. Describe how each of the Construction SWPPP elements has been addressed 8. Stabilize Channels and Outlets: Response: An existing sedimentation pond and drainage � �O� �!,), y (� Belfair,WA(Parcel#12317-41-00060) through the Construction SWPPP Answer: Refer to the following 12 elements.. ditch swales prevent surface water runoff from flown direct) into the Union River. C� b. Identi the 9. Control Pollutants: Res y p Prepared for: Chet and Debbie Louden fY type and location of Best Management Practices used to satisfy the Response: Construction equipment shall be inspected for any oil or ' � B required element. Answer: Refer to the detailed diagram above the type and hydraulic leaks and be properly maintained prior to arrival on site PO. 2326 Pelf Box xWA98528 locations of the applicable BMPs. 10. Control De-Watering: Response: De-watering is not required since the groundwater table 'Z 360 275 7471 c Written justification identifying the reason an element is not appicab�le to the proposal. is located below the bottom of the catchbasins. r __ Answer:Refer to the following 12 elements. 11. Maintain BMPs: Response: .o Prepared by: Morta Engineeringand Testing p Hydroseeding and mulching will be maintained especially 30758 , n9 during periods of heavy extended rainfall periods. `f'p '�FL/S.I EEO C` PO.Box 250,Ocean Shores,WA 98569 12. Manage the Project: Response: The owner will be responsible for managing this project S (�)59U958,(360)289-9682 fax and ensuring that the Construction Stormvater Pollution Prevention Plan is properly and S7�NAL G 1980 NE Old ?1fair N Belfair Hwy b. Description of Existing Vegetation,cont'd: Douglas firs,Cedars, ,�� E Mason County Clearing and Approval Block and ground cover most of the east third of the property as shown in the 92.8'EI.at 18"invert. _ engineering drawing. This will be left all natural by the property owners. "� / Reviewed by: c. Description of Existing Drainage: A 12'diameter culvert under the '� S Old Belfair Highway located just outside the northwest corner of the i Existing 18 dia g Y county culvert j Drainage ditch(wale) Approved by. property and then connects to the county's 24'culvert which then goes \y\ to handle overflow conditions into a drainage ditch on the north side of the property and then the from the 24'culvert during Date. surface water runoff flaws into an I6'diameter culvert which runs down w _ the middle of the` � heavy,continuous rainfall property from the north to south as shown in the drawing. 12'dia.culvert �!�,, Existing drainage X, Note: Clearing and grading limits are shown in light blue Finally,the surface water runoff flows into an existing50'x 100' VI INI M NT P � � ` ditch(swale in the dravHrtg below sedimentation pond before flowing into a naturally vgetated drainage Paved neigborhood with several -= ditch leading to the Union River. parked vehicles on this side of the �\G �� pav�lilure ea,., - _- - �/ 9 roadway.(Contributes to surface ,xP, o q'„ 1,_- 8--- _ Parcel#12317 41 00050 �. Adjacent Areas water runoff} ��tio� 12'dia: " 40' 8tY� i ,:- 90;I. Description of adjacent areas which may be affected b ' �" �. ' ?fa store �;jG4' '" X 118'EI. Proposed drainfield Proposed drainfield _ @disturbance: Y Y ' ------ "8 the site d O w a " location- --_ ___locatic�rt "' - �o`� a. Streams: The Union River is located at the southeast • t Ps �; ' - ,'� --- ----- ----- - - - -- -8$- comer of the property and an unnamed flows and the _ " tl drainfiejd easernerrt _ outside the west end of the property p) eenbe re�elve 20t eaC o� d trees y C, _ - X 97 1 El. X 9y0.6 El. + X •. F V%II(85'd } X 105'E! - Old Belfair Highway This creek has overflowed ' ,-7 iTg B. X 87 8 EI- b. Lakes: There are no lakes in the vicinity of the property. . " D 04,�Opsq.ft �=* toward the 12'culvert _ ^paved area ) X 104'EI. 2A' /,-'' c, Wetlands: Wetlands are located on the south side of -12 diva PVClppe \ }; '- This area to be left all natural the o during the winter and spring X 9tl 6 I. consisting of trees and meadow property along the drainage ditch swaie as shown in months. X 92.3)^I. , a'k the drawing. Appropriate setbacks have been provided ---- -- - �� P - for the location of the expanded sedimentation pond. a,- --- ,; -a ` 1C 5' _ Parcel#12317-41-00060 cg 87_' d. Residential Areas: The main residential is located on Peninsula X 6 EL `d - --( - _ an elevated plateau and is not affected by the asphalted 5U x 100r X g1 _ X 86.5'El. Truss Company addition ;I g• X 8T El: surfacing project. A 24'x 36'house is located at the _ northwest corner of the pro pally�.� 50'x 100' � X 89j9'EI.`, ��$, �g�,�,-- _ ��-- pr pretty but will be removed drainfield ---------------- ---�______-_______ ^ - 1 duringthe pavingoperations. Al2x57 trailer will remain • ---- _ ed d f h ,300 r�y located the o t p perty and is also not -- ---,-------- - -- -----'----�-�-- -_---- - ------------- ---------------- ,, 00 - affected by the - E a 7 -------J------------ 900" -'" - 1000 aff paving work e 9T ; �� -N Et.----X-WE}------------------ ---- ---------------- --------------�--- ;i. Roads: The Old Belfair Highway runs from the southwest ` 96 95 94'� 93 - er se '; ` Drainage ditch(swale) X 86.ti El. � X 85.3'El. to the northeast direction at the outside NW corner of the Install 2'dia.pipe - - T- for 6 month storm o as shown. A 12'diameter culvert under the X g0.5'�l. �E89 Ef•--- R -' X 88 EI. This area to be left all natural highway helps to drain water off the highwayand from the to proposed drainfiebd ! --'"� _ � 0 =0.6 �` at NE corner of property / 91 ','J -- -__ __ _ 18 di consisting of trees and meadow unnamed creek located outside the west en of the \ ---.--22;500sq.ft. ---- a.Colo property, Existing 12'dia/ 90r paved area 10h x 200'x 7'settling potla from 6 high x 18 dia Parcel#12317 41 00070 f. Other: A 50'x 100' truss manufacturing facility will be rig with 3:1(V H)side slope tiserin sett_ling pond. advert to be (future) X 88 4'El. (refer to attached V ANHM2 ( -` - - expanded to 59 x 200'with new asphalt surfacing removed X 89.4'El,'' 50r x lob' ;%jC$ b"E(: - ---._-X 86'El. around the building as shown. A40'x 80'storage simulation results) ; settfliffg,' building is located on the north side of the property with _ UNION R\ the 19'culvert running underneath it. 89" 200(perimeter) ,'" / - ,, Install 12'dia.'/ - , II. Description of the downstream drainage path loadingfrom the site culvert for storm - -" -X- El.-EI- -------X W El. X 88.6.E6 ':_-=-_ '! f 5'setback to the receiving body of water. (Minimum istance of 400 yards.) }��q'F� from wetland - r,� _ / y sewer �, ,.- r /� During heavy rainfall the surface water runoff flows into a 100'x 200'x T _ sedimentation pond and then into a 6'high standpipe which leads to Drarr>age-dd6h fswale} -- natural vegetated drainage ditch where the surface water runoff is 8T 2. Project Description further filtered before it flows into the Union River. The vegetated 8612 Required Elements for the Construction Stormwater Pollution Prevention Plan a. Total Project Area: 5.75 acres drainage ditch acts as a biofiftration facility that runs nearly 300'before b. Total proposed impervious area:4.67 acres flowing to the river. 1. Mark Clearing LfC81ts: Response: Clearing limits are identified in the above drawing a Total area to be disturbed: 4.48 acres DESIGN GUIDELINES and will be marked by survey stake§$rior to construction. S. Critical Areas 2. Establish Construction Access: Response: Main construction access is already in Existing Site Conditions a. Description of critical areas that are on or adjacent to the site: August 2001 Stormwater Management Manual for Western Washington,August 2001 place and is located on the south side of the existing Peninsula Truss building. A relativlely steep embankment is located on the east side of the POND SIZING 3. Control Flow Rates: Response: Refer to the attached Western Washington Hydrological a. Description of the existing topography:The proposed paving area that will need to be protected from slides and Model 11 computer simulation results for this basin which automatically sizes the retention general area of the expansion of the paving soil erosion during heavy extended rainfall periods. An unnamed Computer simulation: Western Washington Hydrological Model version 2(WNI-IM2) pond using actual rainfall data starting in 1955 to 1999. It is recommended that construction is relatively level ground with a difference in is located at the outside west end of the property which flows under with continuous simulation hydrology(HSPF). Predeveloped input(Mason County at takes place during the drier months of the year from June through October to minimize elevation of about 13'with an elevation of 96.3' the Old Belfair Highway but is not affected by the proposed paving 1980 Old Belfair Hwy):Till forest=5.75 acres,impervious surface=0.71 acres from surface water runoff during construction. project ( +Y). g on the north side of the property to den83 5 e l the b. Description of special requirements for working in or near critical Post developed input:Till forest=0.79 acres,till grass=1 acre,impervious area(roof)= 4. Install Sediment Controls: Response: All bare soil areas will be covered with vL�queen south side of the property. The residence lies 0.32 acres,streets,sidewalk,parking=3.85 acres,pond=0.5 acres.(Refer to drawing at the end of each day's work during periods of rainfall greater than T'in a 24 hour areas: The recommended BMPs for stabilize the 60 to 70% above for details on impervious areas.) 9 periods, on a plateau at an elevation of 104'as shown n9 Also,bare soils will be immediately protected if this rainfall occurs during the day and soil in the drawing. An embankment at 118'elev embankment is hydroseeding,mulching,and/or the use of biodegradable disturbing work will need to stop during this time. lies in the upper mid-section of the property. hemp netting to help hold the mulch inplace and to prevent slides and Auto pond sizing: Bottom length x bottom width=134.12'x 134.12=17,990 sq.ft. 5. Stabilize Soils: Response: All exposed soils especially on sloped embankments shall b. Description of existing vegetation: A 300' soil erosion from taking place during heavy rainfall which can be as much Actual pond sizing:98'x 198'=19,400 sq.ft.>17,990 sq.ft.(req'd) OK be protected by hydroseeding and/or mulching to prevent soil erosion arise slides on the long x 20'wide greenbelt consisting of deciduous as 8 inches in a 24 hr period for the 100 year rainfall. steep embankments. trees will be preserved running from east to west 6. Protect slopes: Response: Apply hydroseeding,mulching,and/or visqueen held inpiace as shown in the drawing. CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN CHECKLIST with sandbags to help protect the slopes along the embankments especially during periods (Reference: August 2001 Stormwater Management Manual for Western Washington) of continuous rainfall,i.e., 1"or greater of rainfall in a 24 hour period. I • 7. Protect Drain Inlets: Response: Currently there are no drain inlets or catchbasios on the J E�4 R `1"f0*4 EROSION AND SEDIMENT CONTROL PLAN 1. Construction Stormwater Pollution Prevention Elements site to protect. WAS �T for Peninsula Truss Company, 1980 Old Belfair Hwy a. Describe haw each of the Construction SWPPP elements has been addressed 8. Stabilize Channels and Outlets: Response: An existing sedimentation pond and drainage F KI Belfai r,WA(Parcel#12317-41-00060) Gj O r�(/�4� L/I` through the Construction SWPPP Answer: Refer to the following 12 elements.. ditch swales prevent surface water runoff from flowing directly into the Union River, e Prepared for: Chet and Debbie Loudin b. Identify the type and location of Best Management Practices used to satisfy the 9. Control Pollutants: Response: Construction equipment shall be inspected for any oil or O PO. Box 2326 required element. Answer: Refer to the detailed diagram above the type and hydraulic leaks and be properly maintained prior to arrival on site Belfair,WA 9a528 locations of the applicable BMPs. 10. Control De-Watering: Response: De-watering is not required since the groundwater table Z (360)275-7422 c. Written justification identifying the reason an element is not aPP cable to the proposal. is located below the bottom of the catchbasinss, r7 Answer:Refer to the following 12 elements. 11. Maintain BMPs: Response: Hydroseeding and mulching will be maintained especially '� 30758 Prepared by: Morta Engineering and Testing during periods of heavy extended rainfall periods. fpRF�.IS �p PO.Box 250,Ocean Shores,WA98569 12. Manage the Project: Response: The owner will be responsible for managing this project S (800)590.0958,(360)289-9682 fax and ensuring that the Construction Storrmvater Pollution Prevention Plan is properly and SIGNAL G --- -