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Stormwater Management Design - PLN General - 11/12/2020
RECEIVED NOV 18 2020 C:.-t, o r 615 W. Alder Street E H 6 1 H E E R I H 6\,1 N C l 2724 BLACK LAKE BLVD SW,STE 202 • TUMWATER WA 98512• TEL:360 352-2477• FAX: 360 352-0179• TOLL FREE: 844 204-5179 www.vectorengineetinginc.com L NMN STORMWATER MANAGEMENT DESIGN FOR Brian Stefanko New Single Family Residence 11510 E. State Route 106 Union, WA 98592 November 12, 2020 Owner Engineer/Contact Brian Stefanko Ryan Moore/Kyle Freeman 4775 NE Lamms Lane Vector Engineering, Inc University Place, WA 98446 2724 Black Lake Blvd SW Brian.stefanko@gmail.com Suite 202 (360) 352-2477 � FREE w°F 46358 GISTF t� ts'�SIONAL ��yrj 11.12.2020 VEI Job#2020 STEF Table of Contents Section1 Project Description.......................................................................................................................1 BackgroundSite Description.....................................................................................................................3 SiteData....................................................................................................................................................3 Vicinity&Site Location Maps ...................................................................................................................3 ProjectProposal........................................................................................................................................4 ExistingSite Conditions.............................................................................................................................4 DrainageBasin Characteristics..................................................................................................................4 SensitiveAreas..........................................................................................................................................4 OffsiteImpacts..........................................................................................................................................4 Section 2 Proposed Stormwater Management Plan...................................................................................5 Construction Access Route...........................................................................................................................5 DisturbedSoil Stabilization...........................................................................................................................5 Protection of Neighboring Properties...........................................................................................................6 OtherBMPs Implemented............................................................................................................................6 Maintenance.................................................................................................................................................6 APPENDICES Brian Stefanko Storm Drainage-Narrative VEI Job#2020 Stefanko SFR Union,WA 2 November 2020 i Table of Contents Section 1 Project Description....................................................................................................................... 1 Background Site Description.....................................................................................................................3 SiteData....................................................................................................................................................3 Vicinity &Site Location Maps ...................................................................................................................3 ProjectProposal........................................................................................................................................4 ExistingSite Conditions.............................................................................................................................4 Drainage Basin Characteristics..................................................................................................................4 SensitiveAreas..........................................................................................................................................4 OffsiteImpacts..........................................................................................................................................4 Section 2 Proposed Stormwater Management Plan...................................................................................5 Construction Access Route ...........................................................................................................................5 DisturbedSoil Stabilization...........................................................................................................................5 Protection of Neighboring Properties...........................................................................................................6 OtherBMPs Implemented............................................................................................................................6 Maintenance.................................................................................................................................................6 APPENDICES Brian Stefanko Storm Drainage-Narrative VEI Job#2020 Stefanko SFR Union,WA 2 November 2020 Section 1 —Proposed Project Description Background/Site Description: The project site includes 3 parcels with a total area of 48.78 acres and is located on south side of State Route 106,just west of Twano State Park property. The site is zoned Rural Residential 5 (RR5)for the two parcels closest to the road and Rural Residential 20 (RR20)for large parcel ' back off the road. Rural Residential zoning RR5 allows for a residential development density of one dwelling unit per 5 acres and RR20 allows for one dwelling unit per 20 acres. Site Data is as follows: PN# 222302100021 2.16 Acres Zoning: RR5 PN#222302300010 6.62 Acres Zoning: RR5 PN#222302400000 40.00 Acres Zoning: RR20 Vicinity Map & Site Location 41, r w 1' R.J. ' Vion j� PM PERTY LOCA ION Brian Stefanko Storm Drainage-Narrative VEI Job#2020 Stefanko SFR Union,WA 3 November 2020 r ' Project Proposal: The proposed plan for this project includes the construction of a new house with a footprint of 3,024 s.f., a 12' x 24' (288 s.f.)accessory shed, a driveway with fire access maneuverability and power,water(well), onsite septic system and stormwater erosion control measures. Existing Site Conditions: The site is a presently undeveloped and heavily wooded hillslope extending up from Hood Canal located across the street to the north of the property. A ravine is located on the east side of the property with flowing water that runs northwest to the canal through a culvert that crosses under the highway. This stream has been mapped as a fish bearing stream. The site geologic soils are Pre-Vashon sediments (Qpu)and is suitable for construction in general, as described by the Geotechnical Report conducted for the project by All American Geotechnical. The report also identifies small historical landslides within the ravine area,but nothing within the area of the proposed development. Drainage Basin Characteristics The site is located on the southern hillslope of Hood Canal and drainage of the area runs north and discharges directly into the Canal. On the property, a ravine is located along the east side of the property and the stream contained within it flows to the road, crosses under the highway through a culvert and discharges directly to Hood Canal. General drainage from the property is infiltrated and/or flows north(downhill)to the road and is collected by the south side roadside ditch that collects to the same culvert as the stream mentioned above. Sensitive Areas The stream located within the ravine on the property is identified as a fish bearing stream. In accordance with Mason County Municipal Code(MCC) 8.52.170, a critical areas protection buffer of 150 feet is required for this stream, as well as an additional 15-foot setback for the location of structures/buildings. Landslide Hazard Areas have been identified on the site and within the project vicinity by All American Geotechnical. LHA buffer areas of 50 feet have been identified by them for potentially sensitive slopes on the property. Offsite Impacts In general concurrence with the Geotechnical Report,there should be no notable on or offsite impacts if the project is completed according to our stormwater management and erosion control measures, in conjunction with the recommendations of the geotechnical report for soil management, foundation preparations, and erosion control. Brian Stefanko Storm Drainage-Narrative VEI Job#2020 Stefanko SFR Union,WA 4 November 2020 Section 2—Proposed Stormwater Management& Erosion Control Plan Small Parcel Stormwater Best Management Practices(BMPs)Implementation Construction temporary erosion and sediment control(TESC)BMPs shall be established prior to the start of grading or excavation work on the site. The TESC measures outlined below have been included and identified in the attached drawings for this project. These measures are identified as the minimum required to prevent sediment migration from the project site,however the Contractor shall maintain all • BMPs and implement different measures, as necessary,during the course of construction in order to maintain the site and prevent erosion and offsite sediment transport to the best extent feasible. 1. Construction Access Route Construction vehicle access shall be limited to the one route—the proposed driveway—for all construction access. A stabilized construction entrance,constructed of heavy rock in accordance with BMP C105: Stabilized Construction Entrance shall be utilized until the driveway surface has been completed. Provisions must be made where the access intersects Highway 106. The stabilized construction entrance shall be of sufficient length to prevent tracking of sediment from vehicle traffic onto the highway. In the event that sediment is transported onto the road surface creating a hazard,the road shall be cleaned immediately,and thoroughly cleaned at the end of each day. Sediment shall be removed from roads by shoveling or sweeping and be transported to a controlled sediment disposal area. Street washing shall be allowed only after sediment is removed in this manner. Refer to the project stormwater/tesc drawings&details and the attached BMP info in Appendix B for implementation information. 2. Stabilization of Potentially Erodible Denuded Areas/Soil Stabilization All exposed and unworked soils with erosion potential shall be stabilized using appropriate BMP measures including,but not limited to the following: a. Preservation of Natural Vegetation [BMP C1011 Natural vegetation should be preserved on the site to the best extent possible to preserve the natural drainage holding capacity and erosion resistance of the soils. Natural vegetation should be preserved on steep slopes,near perennial and intermittent watercourses or swales,and on building sites in wooded areas. Natural vegetation can be preserved in natural clumps or as individual trees,shrubs and vines. b. Home Site Clearing Area Timber clearing will be necessary for the house building site and the adjacent surrounding area. Appropriate erosion control measures for the cleared area shall include,as appropriate: - BMP C233: Silt Fence - BMP C 120: Temporary and Permanent Seeding - BMP C 121:Mulching - BMP C124: Sodding - BMP C 123: Plastic Covering Disturbed soils within the clearing area shall not remain exposed for more than 2 days from October 1 through April 30 and not more than 7 days from May 1 through September 30. Exposed soils in the clearing area can be temporarily or permanently seeded(or sodded)within the timeframe mentioned above. During the non-growing season,mulch shall be included with the seeding. Foundation excavation stockpiles should be protected with plastic covering or temporary seeding if being left for an extended period of time,or prior to a storm event. Silt fence should be used in areas of high runoff erosion potential areas,toes of slopes,or the downstream side of stockpiles to prevent silt migration. Brian Stefanko Storm Drainage-Narrative VEI Job#2020 Stefanko SFR Union,WA 5 November 2020 c. Driveway ' Driveway rough grading shall be protected from erosion until the surfacing material and roadside ditch protection measures can be implemented. Applicable BMPs include: - BMP C 121:Mulching - BMP C 130: Surface Roughening Straw(mulching)can be placed on rough graded soils not being worked for timeframes longer than those listed above. Driveway cut/fill slopes greater than or equal to 3:1 and 5 vertical feet shall receive surface roughening prior to seeding to reduce the runoff velocity on the slopes and aid in vegetation cover establishment. 3. Protection of Adjacent Properties Adjacent properties are proposed to be protected from offsite sediment transport and erosion potential by means of maintaining sufficient natural vegetation buffers from the property lines and implementation of stormwater management BMPs to direct site stormwater runoff from buildings and cleared areas to appropriate infiltration areas onsite. 4. Other BMPs The following permanent stormwater management BMPs are proposed for the site as follows: a. Driveway The surface of the driveway will be paved with asphalt, given the high proposed grade, to prevent migration of surface gravel fines off the surface. Additionally,check dams[BMP C207: Check Dams] shall be installed in the roadside ditches to slow the velocity of collected runoff and trap runoff sediment. Additionally,since the ditch slopes exceed 10%in grade,they shall be lined with 8"minus quarry spalls to prevent channel erosion [BMP C202: Channel Lining]. b. Roof Runoff Runoff from the roofs of the house and shed will be collected by roof gutters and directed to downspout tightlines that can be discharged in locations where the runoff can be dispersed appropriately. The geotechnical report has identified the steep slope area to the east as an inappropriate location for directing of roof runoff and shall be avoided. —= Additionally,rainwater harvesting cisterns are proposed to be utilized for the house and/or shed[BMP T5.20: Rainwater Harvesting]. Harvested rainwater shall be limited to nonpotable uses such as outside irrigation,toilet flushing or cold water laundry. Runoff not collected in the cisterns, or excess runoff overflow, shall be directed back to the downspout tightline for dispersion in the appropriate location. 5. Maintenance All erosion and sediment control BMPs implemented on the site shall be regularly inspected and maintained by the owner or authorized agent to ensure continued performance of their intended function and prevent sediment runoff from the site,to the maximum extent possible. All temporary erosion and sediment control BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be removed or stabilized onsite. Disturbed soil areas resulting from removal of BMPs or vegetation shall be permanently stabilized. See Appendix B for more information on BMP Installation and Maintenance Standards. Brian Stefanko Storm Drainage-Narrative VEI Job#2020 Stefanko SFR Union,WA 6 November 2020 Appendix A Plans NEW SINGLE FAMIL Y RESIDENCE 11510 EAST STATE ROUTE 106,UN/ON,WA PROJECT INFORMATION OWNER SITELOCATION BRIAN STEFANKO SEC:30 T.•22 N R.2 W 4775 NE LAMMS LANE \ POULSBO,WA 98370 PARCEL NO's 4 / brlan-stsfank.@g—ol. m 222302100021 I 222302300010 CIVIL ENGINEER 222302400000 KYLE FREEMAN,P.E. \' VECTOR ENGINEERING,INC JURISDICTION 4• 2724 BLACK LAKE BL VD SW MASON COUNTY F TUMWATER,WA 96512 PHONE: (360)352-2477 t kheeman@vectorenginesnnginc.com \ ` \ GEOTECHNICAL / CURTIS D.CUSHMAN,E.G. ALL AMERICAN GEOTECHNICAL,INC 8947B4 \ O MPIATWAWOOD 98516 ENE NE \\ I PHONE: (360)491-5155 0000 Curtis.Cushman@comcast-nef ROAD DESIGN CRITERIA Q MINIMUM ROAD WIDTH=12'- I`S .�'✓/ l MAXIMUM ROAD GRADE=14% MINIMUM TURNING RADIUS=25 R(INSIDE)/45 R(OUTSIDE) FIREAPPARATUS TURNOUTS=8 R(W)x 30 R(L)w/TAPERS ( AND 150 R ON CENTER. FIREAPPARATUS TURNAROUND=HAMMERHEAD, 1y '� CUL-DE-SAC,OR MODIFIED HAMMERHEAD TURNAROUND, I MEETING MASON COUNTY BUILDING CODE CH.14.17 1 DIMENSIONS,AND NOT MORE THAN 150 R FROM THE F o STRUCTURE BEING SERVED. r *NOTE. THE ROAD LAYOUT,AS SHOWN IN THESE 1 N ALTERNA4€HOUSE� LOCATION AYDR WAY \ �� DRAWINGS,MAYBE FIELD-ADJUSTED BASED ON THE JUDGEMENT OF THE CONTRICTOR PROVIDED THE ABOVE-DESCRIBED ROAD DESIGN � CRITERIA ARE MAINTAINED. R LINE Y ;T 200 }`,,,OPOSED Sl TURNOUTS,AS SHOWN,SHALL NOT BE REQUIRED \ I S� F.4MLR Y REEEESIDENCCI 1FA20'MIN ROAD WIDTH IS PROVIDED INSTEAD. (3,OT SF-FOO, T �r u, 2 302t 2 SURVEYDATA 6ACRE) / I 125 THIS IS NOTA BOUNDARY SURVEY. THE PROPERTY LINES INDICATED IN THIS DRAWING ARE BASED ON AVAILABLE COUNTY PARCEL DATA DEEMED SUFFICIENT FOR THE _ WORK INTENDED. THE TOPOGRAPHIC DATA PRESENTED/S BASED ON s 12 yr 24' Q S AVAILABLE LIDAR DATA COLLECTED FROM THE LOWER (A ESSDRY STRC. P/J�I;�Q3QQ3D�O PUGET SOUND PRQIECT,MASON COUNTY COLLECTION 5 D ii S) AREA!N 2002. LOCAL TOPOGRAPHICAL DATA MAY NEED TO s 7- ONSIAE SEPT PRIMAR BE COLLECTED IF THE SITE APPEARS ALTERED FROM THAT > RES RVE DRA ELD AR E LIN DEPICTED IN THESE DRAWINGS. 9 SHEET LIST ED ORNEwA1�. ° SHEETNO. TITLE C1.0 TITLE SHEET&GENERAL LAYOUT C2.0 ROAD PLAN&PROFILE SITE PLAN 0 100, 200' CIO STORMWATER 8 TESC PLAN SCALE:1'=f00' l� C4.0 DETAILS&NOTES-ROADWAY I C5.0 DETAILS&NOTES-STORM/TESC FxeK-6ASE.ay (j) DRIVEWAYACCESSDESIGNPROJECT'763TEF t t1151a ESTATE ROUTE f05 -O, PERMIT SET uNioN,wnsN NCTON COVERSHEET6 cNECKEDer.KJFE N G I N E E R I N G I N C SITE PUN DEEMED er.,KIF n2a e ev.L®ts eome�n/slv scare zoz BR/AN STE S LANE DESM.NED BY'KJF DATE ND REV/SAdJ BYIT15NElAMMSUNE/11 M 1360135?-2m/a::(3601352-0119 E-^vAwb^e•� pr �rgic.cpn POUTSBO,WA 93310 SNT 1 OF 5 1 � > BUF OF V A �_ \ t _—��1 \��V y I • m u \ BU `g - i 1 30 t \ 14 i ro o 150'0.c TAPERS�RNOUT w/ i, \ t MODIFIED I MERHEADFIR�\ ,) 7H�1TM APPARATUS'TURNAROUND PVI STA:4+7622 160 - 160 PVI E EV:22.34' _. K 17.78 140 0.83 140 LV :1 .00' pf 120 g�y���f 8 A � y�y � — 120 S NVjU N C ILI N IL c> > 9. 0% -U 100 U INSTALL 18'HD CULVERT.LOC TEATCL OFEXI . EXISTING m __,— 100 m - ROADSIDE DITCJ I FLOMINE.BED PIPE PER DETAIL , - GRADE —'-_- 80 SHEET C-04ANE PROVIDE 12'MIN COVER OVER PI 80 60 1Y 60 _ ...f GRADE ........ 40 ——— 40 a 20 - — 20 �19, 96 w � w b W G w � w`� w Lb w" w w � Ea i5 -0+30 MUD 0+50 1+00 1+50 2400 2+50 3+00 3+50 4-M 4+50 5+00 5+50 M00 6+50 7-00 DRIVEWAY PLAN&PROFILE o 50' 1 ou 1�1� SCALE.,1'=50' 4 FM.E X-B4SEd" ` Y.N 1 DRIVEWAYACCESS DESIGN PROJECT.MSTEF Q `nvyk'/ ,••••••1,'—r 11UNtl ,ATEROVTON C-O2 PERMIT SET NNAN,W�HlhSTEF TON CHECKED BY.'KJF ROAD PLAN e E N G I N E E R I N G\N C PROFILE QQQ OETAkEO BY.'IG1� 2721 Black Lek,BwA—v SW Sui`202 B 775 NE" S"NE O DESIGNED BY.K3F OATS NO. RfNSIQV BY T—Ifer,WA 9B512 1/f 120 Pl,:(360J 352.211T/ex:(3501 352-0 1 79 E-mail:edmwr�veclorenginwiingmc.cpn POUlSBO,WA 88370 SHT 2 OF 5 • f BMPC101:PRESERVE NATURAL VEGETATION / m BUF ' i BMPC705 STABILIZED C G S ST Ll DA d C-05 CONSTRUCTION ENTRANCE OyERED MU AND/OR STRAW 1 EDl NO B ACCOMPLISI" IMMED Y. BUF SEE I C12 P6 E ING S, E OF'� BVF R M R INFO h ION BUF— BMP C207.CHECK DAMS 3 � 1 INCL.CHANNEL LINING C-00 q W MOUSE > .81 / ' C} x A N BMP C101:PRESERVE m NATURAL VEGETATION 41 ~ A m m BMP T520.'RAINWATER HARVETI p RAINWATER COLLECTION CISTERNSAR NNED R15 PR n FOR THE HOUSE,SHED OR BOTH(TBD).O HARVESTED RAINWATER m PF T a SHALL BE LIMITED TO\ = p 'QTy in NONPOTABLE USES SUCH AS OUTSIDE IRRIGATION, - ��NF TOILET FLUSHING OR COLD WATER LAUNDRY. tm '� BMP C101:PRESERVE NATURAL VEGETATION STORMWATER& TESC PLAN 0 59 Boa SCALE'1'=50' 'FILE:X-a�,-v g.a DRIVEWAY ACCESS DESIGN PROJECT.-24STEF © "t 11510ESTATEROUTE 106 C-03 LIMON WASHINGTON CHECKED BY.'XJF PERMIT SET E N G I N E E R I N G\N C STOR—ATER a BRIAN STEFANKO TESC PLAN IDETAILED BY:K.i _ 1714 Black Lake Boubvard SW Suire 201 47 5 NE LAWS LANE DESIGNED BY.K.F GATE NO. REVISION BY Tumwatar,WA 99512 K �'f/f f P'`:(3601 J52-1dT7 fax:(360)352-0iT9 E-mail:adminQwcfwegin•einguic.ttm POLKSBO,WA A&i70 SHT .� OF Jr TRENCH WIDTH (SEE NOTE 3) GRAVEL BACKFILL FOR PIPE ZONE BEDDING 6 (SEE NOTE 2) w r; 3.00' a a J% 3% 3:1 3,T FOUNDATION LEVEL io ROAD SEcnoNrowctuDE THERMOPLASTIC PIPE NOTES.' 2 1F1) MIN.US TH TOP COURSE (CLASS A) 1. SEE WSDOT STANDARD SPECIFICATION SECTION 7-06.3(3)FOR 1 2' MINUS TOP COURSE(3'THICK) PIPE ZONE BACKFILL 2 1/2'MINUS BASE COURSE(6'THICK) 2 SEE WSDOT STANDARD SPECIFICATION SECTION 9-03.12(3)FOR GRAVEL BACKFILL FOR PIPE ZONE BEDDING. DR/VEWAYSECT/ON 3. FOR SANITARY SEWER INSTALLAT/ON,CONCRETE PIPE SHALL BE BEDDED TO SPRING LINE. C-04 SCALE:1/4—1'-0' �1 CROSS-CULVERT BEDDING C-09 SCALE.'N.T.S. u1 w CHECK DAMS NOTES 1. THE MAXIMUM SPACING BETWEEN THE DAMS SHALL BE SUCH THAT THE TOE OF THE UPSTREAM DAM IS AT THE SAME ELEVATION AS THE TOP OF THE KEY INTO CHANNEL DOWNSTREAMDAM 2. ROCK CHECK DAMS SHALL BE CONSTRUCTED OF 6'MINUS QUARRY SPALLS. FloM, THE ROCK MUST BE PLACED BYHAND OR MECHANICAL PLACEMENT TO ACHIEVE Q�Q �� TOP OF CHECK DAM TO COMPLETE COVERAGE OF THE DITCH OR SWALEAND TO ENSURE THAT THE R BE AT BOTTOM OF PREVIOUS CENTER OF THE DAM IS LOWER THAN THE EDGES.THE ROCK USED MUST BE CHECK DAM ELEVATION LARGE ENOUGH TO STAY IN PLACE GIVEN THE EXPECTED DESIGN FLOW THROUGH THE CHANNEL.PROVIDEA SUMP IMMEDIATELY UPSTREAM OF CHECK DAMS. 3 MAINTENANCE,CHECK DAMS SHALL BE MONITORED FOR PERFORMANCE AND SPACING 1MLL SEDIMENT ACCUMULATION DURING AND AFTER EACH RUNOFF PRODUCING VARY RAINFALL. SEDIMENT SHALL BE REMOVED WHEN IT REACHES ONE HALF THE SEC ON SUMP DEPTH TRAPPED SEDIMENT SHALL BE REMOVED OR STABILIZED ON SITE. A 4. IN ADDITION TO CHECK DAMS,CHANNEL SHALL BE LINED WITH B'MINUS QUARRY SPALLS MEETING WSDOT SPEC 9.13.1(5)FOR GRADES GREATER THAN 10%. r31 ROADWAY DITCH CHECK DAMS C-06 SCALE N.T.S. Frcex-asE.°"y Luc,..� DRIVEWAYACCESSDESIGN C� T:PROJEC 2"TEF c;�1. 11510 E STATE ROUTE IM —�----- UMOId WASHNGTOW a C/Ef MBY.K•/F PERMIT SET E N G I N E E R I N G\N C . GETROADWATES- R BR/AN STEFANKO ROADWAY SW DETALED BY:KJF f Bf of f t•B,WA 9 51 Suits 101 DESKBED BY KJF DATE NO. REYISVN BY T2.017Y WA B7511 IOUSS AMMS 370 SHT 4 OF 5 K l?G M'(%0J352.71)7 he(.%O)A52-0fT8 E-nri!'�nmm PCIASBO.WA A?970 a v 0 • ' JOINTS IN FILTER FABRIC SHALL BE BMP C 120:TEMPORARYAND PERMANENT SEEDING NOTES 2'x2xi4GA.WIREFABRICOR SPLICEDATPOSTS. USESTAPLES, 1. SEED MIXTURE AND APPLICATION RA TE SHALL BE APPROPRIATE FOR THEAREA EQUIVALENT,IF STANDARD WIRE RINGS,OR EQUIVALENT TO AND TYPE OF COVER PROVIDED. STRENGTH FABRIC USED ATTACH FABRIC TO POSTS. 2. WHEN APPLIED WITH HYDROMULCH,APPLY IN TWO PHASES: / 2k2'x14GA.WIRE FABRIC B.PHASE 1-INSTALL ALL SEED AND FERTILIZER WITH 25 TO 30 PERCENT MULCHAND TACKIFIER ONTO SOIL IN THE FIRST LIFT INSTALL DRIVEWAY 1-1 OR OR EQUIVALENT b.PHASE 2-INSTALL THE REST OF THE MULCHAND TACKIFIER IN THE SECOND LIFT. CULVERT I ROADSIDE 3. IF FEASIBLE,SEED BETWEEN APRIL 1 AND JUNE 30 OR BETWEEN SEPTEMBER 1 DITCH PRESENT OPp`fIP ��,N AND OCTOBER I. / / YS1Y�G R N 4 75 PERCENT GRASS COVSEEDBEDS PLANTED EER S EN ESTABLISHED.AUGUST 30 SHALL BE IRRIGATED UNTIL N S. SEED BEDS PLANTED BETWEEN OCTOBER 1 AND MARCH 30 SHALL SE MULCHED WITH STRAW ORAN EROSION CONTROL BLANKET UNTIL 75 PERCENT GRASS COVER _ 2 IS ESTABLISHED. B. CONFIRM 7HE INSTALLATION OFALL REQUIRED SURFACE WATER CONTROL N MEASURES PRIOR TO SEEDING. 7. SEED BEDS SHALL BE FIRMAND ROUGH PRIOR TO SEEDING.WHERE COMPACTION �5 IS REQUIRED FOR ENGINEERING PURPOSES,SLOPES SHALL BE TRACK WALKED B MAX BEFORE SEEDING. 4 8'QUARRYSPALLS GEOTEXTEE POST SPACING MAYBE 8. SACKBLAD/NG OR SMOOTHING IS PROHIBITED ON SEED BEDS STEEPER THAN 4:1. 12'MIN.DEPTH INCREASED 9. IT IS RECOMMENDED THAT AREAS BEING SEEDED FOR FINAL LANDSCAPING (SEE NOTE 1) PRONDEFULL WIDTH MIN/MUM 4x4 TRENCH TO 8'IF WIRE BACKING IS USED CONDUCTSO)L TESTS TO DETERMINE THE EXACT TYPEAND QUANTITY OF OF/NGRESS/EGRESS AREA BACKFILL TRENCH WITH 2x4 WOOD POSTS, FERTILIZER NEEDED.MINIMIZE USE OF FERTILIZER ADJACENT TO WATER BODIES NATIVE SOIL OR 3/4'-1 1/1' STEEL FENCE POST, AND WETLANDS. WASHED GRAVEL REBAR OR EQUIVALENT STANDARD EROSION CONTROL NOTES OES/GNAMJ/AS'T4CLAT/ON SPEC1r1C4r/LN5 GEOTEX77LE SPEC/F/CATIONS 1. EROSION CONTROL MEASURES SHALL BE INSTALLED AND APPROVED BY THE POLYMERIC MESHAOS 0.60;7 MAX FOR SLIT FILM WOVEN(#30 SIEVE) COUNTY PRIOR TO THE BEGINNING OF CONSTRUCTION. 1. STABILIZED CONSTRUCTION ENTRANCE SHALL BE CONSTRUCTED OF A 12-THICK (ASTM D4751) 0.30 mIn FORALL OTHER GEOTEX77LE TYPES(450 SIEVE) 2. EROSION CONTROL MEASURES ARE NOT LIMITED TO ITEMS AS SHOWN ON PLANS PAD OF418'QUARRYSPALLS. 0.15-MIN.FOR ALL FABRIC TYPES(X100 SIEVE) OR ON STANDARD DETAILS. THE CONTRACTOR IS RESPONSIBLE FOR THE ALTERNATIVELY:A4'COURSE OFASPHALT TREATED SASE(ATB),OR THE WA TER PERMITTIVITY 0.02SEC' INSTALLATION AND MAINTENANCE OFALL EROSION CONTROL MEASURES. EXISTING PAVEMENT,MAYBE USED. (ASTM D4491) CONTRACTOR SHALL IMPLEMENT MEASURES TO PREVENT MIGRATION OF SILT 2 THE 100'MIN.LENGTH OF THE ENTRANCE MAY BE REDUCED TO THE MAX/MUM GRAB TENSILE STRENGTH 180 LB.MIN.FOR EXTRA STRENGTH AND/OR POLLUTED RUNOFF TO OFF-SITE PROPERTIES. PRACTICABLE SIZE WHEN THE SIZE OR CONFIGURATION OF THE SITE DOES NOT (ASTM D4632) 100 LB.MIN.FOR STANDARD STRENGTH 3. THE CONTRACTOR WILL MAKE REGULAR SURVEILLANCE OF ALL EROSION CONTROL ALLOW THE FULL LENGTH(100). GRAB TENSILE STRENGTH 30%U4XIMUM MEASURES. THE CONTRACTOR WILL MAKE ALL NECESSARYREPAIRS. (ASTM D4632) MODIFICATIONS,AND ADDITIONS,AS NECESSARY TO ENSURE THE PROPER 3. A SEPARATION GEOTEXTILE SHALL BE PLACED UNDER THE SPALLS TO PREVENT ULTRAVIOLET RESISTANCE 70%MINIMUM OPERATION OF THE EROSION CONTROL MEASURES. THE CONTRACTOR SHALL FINE SEDIMENT FROM PUMPING UP INTO THE ROCK PAD.THE GEOTEX77LE (AS7MD03.55) I EMPLOY MORE FREQUENT INSPECTIONS OF EROSION CONTROL MEASURES SHOULD SHALL MEET THE FOLLOWING STANDARDS.' ALL GEOTEXTILE PROPER77ES LISTED ABOVE ARE MINIMUMAVERAGE ROLL VALUES SITE OR WEA THER CONDITIONS DICTA 7F. 4. ALL DISTURBED AREAS SHALL BE SEEDED OR SODDED UPON COMPLETION OF GRAB TENSILE STRENGTH(ASTM D4751J 200 PSI(MIN.) BMP C233:SILT FENCE NOTES WORK.DURING THE WET SEASON,NOVEMBER THROUGH MARCH,ALL DISTURBED 1. CONSTRUCT SILT FENCES INAREAS OF CLEARING,GRADING,OR DRAINAGE PRIOR SOILS WILL BE STABILIZED WITHIN FORTY-EIGHT(48)HOURSAFTER LAND GRAB TENSILEELONGATION(ASTMO4632) 30%(MAX.) TO STARTING THOSE ACTIVITIES. DISTURBANCEACTIVITIES HAVE CEASED. EROSION CONTROL STABILIZATION 2 A TTACH THE FILTER FABRIC ON THE UP-SLOPE SIDE OF THE POSTS AND SECURE MEASURES WILL INCLUDE,BUTARE NOT LIMITED TO,INSTALLATION OFSTRAW MULLEN BURST STRENGTH(ASTM D3786-808) 400 PSI(MIN.) WITH STAPLES,WIRE,OR INACCORDANCE WITH THE MANUFACTURERS MATTING,JUTE MATTING,STRAW MULCH AND/OR WOOD CHIPS,AND COVERING THE AOS(ASTM D4751) 20-45(U.S.STANDARD SIEVE SIZE) RECOMMENDATIONS.ATTACH THE FILTER FABRIC TO THE POSTS IN A MANNER AFFECTED AREA AND SPOIL PILES WITH PLASTIC SHEETING. THE CONTRACTOR THAT REDUCES THE POTENTIAL FOR TEARING. WILL BE RESPONSIBLE TO ENSURE THAT COMPLETE COVERAGE OF THE DISTURBED 4. FENCING(SEE BMPS C103)SHALL BE INSTALLED AS NECESSARY TO RESTRICT 3. BURY THE BOTTOM OF THE FILTER FABRIC 4-INCHES MIN.BELOW THE GROUND AREAS IS PROVIDED AND THAT GROWTH OF VEGETATION/S ESTABLISHED.SEED TRAFFIC TO THE CONSTRUCTION ENTRANCE. SURFACE.BACKFILL AND TAMP SOIL IN PLACE OVER THE BURIED PORTION OF THE AND SOD APPLICATIONS WILL BE CONDUCTED IN ACCORDANCE WITH THE FILTER FABRIC,SO THAT NO FLOW CAN PASS BENEATH THE FENCE AND SCOURING TIMELINES NOTED IN THE MOST RECENT EDITION OF THE STANDARD 5. WHENEVER POSSIBLE,THE ENTRANCE SHALL BE CONSTRUCTED ON FIRM, CANNOT OCCUR.WHEN WIRE OR POLYMERIC BACK-UP SUPPORT MESH IS USED, SPECIFICATIONS. COMPACTED SUBGRADE.THIS CAN SUBSTANTIALLY INCREASE THE THE WIRE OR POLYMERIC MESH SHALL EXTEND INTO THE GROUND 3-INCHES MIN. 5. THE CONTRACTOR WILL CHECKALL SEEDED OR SODDED AREAS REGULARLY TO EFFECTIVENESS OF THE PAD AND REDUCE THE NEED FOR MAINTENANCE 4. USE WOOD STEEL OR EQUIVALENT POSTS.THE SPACING OF THE SUPPORT POSTS ENSURE THAT THE VEGETATIVE COVER IS BEING ADEQUATELY ESTABLISHED.AREAS SHALL BE A MAXIMUM OF 6-FEET.POSTS SHALL CONSIST OF EITHER. WILL BE REPAIRED,RESEEDED,AND FERTILIZED AS REQUIRED. 6. CONSTRUCT AND MAINTAIN THE CONSTRUCTION ENTRANCE IN ACCORDANCE 4.1. WOOD WITH DIMENSIONS OF 2-INCHES BY24NCHES WIDE MIN.AND A 3-FEET 6. TRACKING OF SOIL OFF-SITE WILL NOT BEALLOWED. IFANYSOIL IS TRACKED WITH THE DEPARTMENT OF ECOLOGYSTANDARDS(STORMWATER MANAGEMENT MIN.LENGTH.WOOD POSTS SHALL BE FREE OF DEFECTS SUCH AS KNOTS, BEYOND THE LIMITS OF THE SITE,IT WILL BE REMOVED BEFORE THE END OF THAT MANUAL,LATEST EDITION). SPLITS,OR GOUGES. WORKING DAY TO PREVENT ADDITIONAL TRACKING,VEHICLE TIRES MUST BE 3 4.2. NO.6 STEEL REBAR OR LARGER. SWEPT OR WASHED PRIOR TO LEAVING THE PROJECT SITE. 4.3. ASTM A 120 STEEL PIPE WITH A MINIMUM DIAMETER OF 1-INCH. AN 500 LINEAR FEET(CFI OF NO MORE TH AN H TRENCH DNA DOWN-SLOPE OF MORE 4.4. U,T,L,OR C SHAPE STEEL POSTS WITH A MINIMUM WEIGHT OF 1.35 LBS.IFT. THAN FIVE(5)PERCENT WILL BE OPENEDTR ONE TIME. 4.5 OTHER STEEL POSTS HAVING EQUIVALENT STRENGTH AND BENDING RESISTANCE TO THE POST SIZES LISTED ABOVE 8. EXCAVATED MATERIAL WILL BE PLACED ON THE UPHILL SIDE OF TRENCHES. 9. EXCAVATED MATERIAL WILL NOT BE PLACED IN ESTABLISHED DRAINAGE DITCHES, UNDER ANY CIRCUMSTANCES. �1 STABILIZED CONSTRUCTION ENTRANCE �z1 SILT FENCE 10. CONTRACTOR SHALL ESTABL/SHA SEDIMENT TRAP FOR ALL TRENCH DI.. C-05 SCAC£N.T.S. C-05 SGLE:NTS. OPERATIONS. d FXExAA A"p a y DRIVEWAYACCESS DESIGN PROJECT..24S7EF ,+°.w.��: 1 f5fO E STATE ROUTE 106 C-05 -_ LIMON WASHINGTON PERMIT SET DETAN.S8N MS- cHEcxEoer.xJF J E N G I N E E R I N G I N C . STORM/TESC \ BRIAN STEFANKO DETAN.fD BY.K1F 2T24 Black Lake Boubma SW Suits 202 4775NELAMMSLANE DESIGNED BY..K6 DATE NO. REVISION By 52-017er,WA AYSIT 1H1/M P'(960)357.247J Iar'(360135 fff,WA ROULSBO.WA98370 SNT Jr OF Jr Appendix B Stormwater/TESC Best Management Practices (BMPs) Installation & Maintenance Instructions 4.1 Source Control BMPs BMP C101: Preserving Natural Vegetation I'rli-pose The purpose of preserving natural vegetation is to reduce erosion wherever practicable. Limiting site disturbance is the single most effective method for reducing erosion. For example, conifers can hold up to about 50 percent of all rain that falls during a storm. Up to 20-30 percent of this rain may never reach the ground but is taken up by the tree or evaporates. Another benefit is that the rain held in the tree can be released slowly to the ground after the storm. Conditions of Use • Natural vegetation should be preserved on steep slopes,near perennial and intermittent watercourses or swales, and on building sites in wooded areas. • As required by local governments. Design and Natural vegetation can be preserved in natural clumps or as individual Installation trees, shrubs and vines. Specifications The preservation of individual plants is more difficult because heavy equipment is generally used to remove unwanted vegetation. The points to remember when attempting to save individual plants are: • Is the plant worth saving? Consider the location,species,size,age, vigor,and the work involved. Local governments may also have ordinances to save natural vegetation and trees. • Fence or clearly mark areas around trees that are to be saved. It is preferable to keep ground disturbance away from the trees at least as far out as the dripline. Plants need protection from three kinds of injuries: • Construction Equipment- This injury can be above or below the ground level. Damage results from scarring, cutting of roots,and compaction of the soil. Placing a fenced buffer zone around plants to be saved prior to construction can prevent construction equipment injuries. • Grade Changes-Changing the natural ground level will alter grades, which affects the plant's ability to obtain the necessary air,water, and minerals. Minor fills usually do not cause problems although sensitivity between species does vary and should be checked. Trees can tolerate fill of 6 inches or less. For shrubs and other plants,the fill should be less. When there are major changes in grade, it may become necessary to supply air to the roots of plants. This can be done by placing a layer of gravel and a tile system over the roots before the fill is made. A tile 4-2 Volume 11—Construction Stormwater Pollution Prevention February 2005 system protects a tree from a raised grade. The the system should be laid out on the original grade leading from a dry well around the tree trunk. The system should then be covered with small stones to allow air to circulate over the root area. Lowering the natural ground level can seriously damage trees and shrubs. The highest percentage of the plant roots are in the upper 12 inches of the soil and cuts of only 2-3 inches can cause serious injury. To protect the roots it may be necessary to terrace the immediate area around the plants to be saved. If roots are exposed, construction of retaining walls may be needed to keep the soil in place. Plants can also be preserved by leaving them on an undisturbed,gently sloping mound. To increase the chances for survival, it is best to limit grade changes and other soil disturbances to areas outside the dripline of the plant. • Excavations-Protect trees and other plants when excavating for drainfields,power,water,and sewer lines. Where possible,the trenches should be routed around trees and large shrubs. When this is not possible, it is best to tunnel under them. This can be done with hand tools or with power augers. If it is not possible to route the trench around plants to be saved,then the following should be observed: Cut as few roots as possible. When you have to cut, cut clean. Paint cut root ends with a wood dressing like asphalt base paint. Backfill the trench as soon as possible. Tunnel beneath root systems as close to the center of the main trunk to preserve most of the important feeder roots. Some problems that can be encountered with a few specific trees are: • Maple, Dogwood, Red alder, Western hemlock, Western red cedar, and Douglas fir do not readily adjust to changes in environment and special care should be taken to protect these trees. • The windthrow hazard of Pacific silver fir and madronna is high,while that of Western hemlock is moderate. The danger of windthrow increases where dense stands have been thinned. Other species(unless they are on shallow,wet soils less than 20 inches deep)have a low windthrow hazard. • Cottonwoods,maples,and willows have water-seeking roots. These can cause trouble in sewer lines and infiltration fields. On the other hand,they thrive in high moisture conditions that other trees would not. • Thinning operations in pure or mixed stands of Grand fir, Pacific silver fir,Noble fir, Sitka spruce, Western red cedar, Western hemlock, February 2005 Volume 11—Construction Stormwater Pollution Prevention 4-3 Pacific dogwood, and Red alder can cause serious disease problems. Disease can become established through damaged limbs,trunks,roots, and freshly cut stumps. Diseased and weakened trees are also susceptible to insect attack. Maintenance Inspect flagged and/or fenced areas regularly to make sure flagging or Standards fencing has not been removed or damaged. If the flagging or fencing has been damaged or visibility reduced, it shall be repaired or replaced immediately and visibility restored. • If tree roots have been exposed or injured, "prune" cleanly with an appropriate pruning saw or lopers directly above the damaged roots and recover with native soils. Treatment of sap flowing trees (fir, hemlock, pine, soft maples) is not advised as sap forms a natural healing barrier. 4-4 Volume 11—Construction Stormwater Pollution Prevention February 2005 BMP C105: Stabilized Construction Entrance • Purpose Construction entrances are stabilized to reduce the amount of sediment transported onto paved roads by vehicles or equipment by constructing a stabilized pad of quarry spalls at entrances to construction sites. Conditions of Use Construction entrances shall be stabilized wherever traffic will be leaving a construction site and traveling on paved roads or other paved areas within 1,000 feet of the site. On large commercial, highway,and road projects,the designer should include enough extra materials in the contract to allow for additional stabilized entrances not shown in the initial Construction SWPPP. It is difficult to determine exactly where access to these projects will take place; additional materials will enable the contractor to install them where needed. Design and . See Figure 4.2 for details.Note: the 100' minimum length of the Installation entrance shall be reduced to the maximum practicable size when the Specifications size or configuration of the site does not allow the full length(100'). A separation geotextile shall be placed under the spalls to prevent fine sediment from pumping up into the rock pad. The geotextile shall meet the following standards: Grab Tensile Strength (ASTM D4751) 200 psi min. Grab Tensile Elongation (ASTM D4632) 30% max. Mullen Burst Strength (ASTM D3786-80a) 400 psi min. AOS (ASTM D4751) 20-45(U.S. standard sieve size) • Consider early installation of the first lift of asphalt in areas that will paved;this can be used as a stabilized entrance. Also consider the installation of excess concrete as a stabilized entrance. During large concrete pours, excess concrete is often available for this purpose. • Hog fuel (wood-based mulch)may be substituted for or combined with quarry spalls in areas that will not be used for permanent roads. Hog fuel is generally less effective at stabilizing construction entrances and should be used only at sites where the amount of traffic is very limited. Hog fuel is not recommended for entrance stabilization in urban areas. The effectiveness of hog fuel is highly variable and it generally requires more maintenance than quarry spalls. The inspector may at any time require the use of quarry spalls if the hog fuel is not preventing sediment from being tracked onto pavement or if the hog fuel is being carried onto pavement. Hog fuel is prohibited in permanent roadbeds because organics in the subgrade soils cause degradation of the subgrade support over time. • Fencing(see BMWs C 103 and C 104) shall be installed as necessary to restrict traffic to the construction entrance. 4-8 Volume 11—Construction Stormwater Pollution Prevention February 2005 • Whenever possible,the entrance shall be constructed on a firm, compacted subgrade. This can substantially increase the effectiveness of the pad and reduce the need for maintenance. Maintenance • Quarry spalls (or hog fuel) shall be added if the pad is no longer in Standards accordance with the specifications. If the entrance is not preventing sediment from being tracked onto pavement,then alternative measures to keep the streets free of _ sediment shall be used. This may include street sweeping, an increase in the dimensions of the entrance, or the installation of a wheel wash. Any sediment that is tracked onto pavement shall be removed by shoveling or street sweeping. The sediment collected by sweeping shall be removed or stabilized on site. The pavement shall not be cleaned by washing down the street, except when sweeping is ineffective and there is a threat to public safety. If it is necessary to wash the streets,the construction of a small sump shall be considered. The sediment would then be washed into the sump where it can be controlled. Any quarry spalls that are loosened from the pad,which end up on the roadway shall be removed immediately. If vehicles are entering or exiting the site at points other than the construction entrance(s), fencing(see BMPs C 103 and C 104) shall be installed to control traffic. • Upon project completion and site stabilization, all construction accesses intended as permanent access for maintenance shall be permanently stabilized. Driveway shall meet the requirements of the permitting agency It is recommended that the entrance be crowned so that runoff oyp drains off the pad P r i Install driveway culvert \\\ if there is a roadside ditch present 4"-8"quarry spells Geolextile 12"min.thickness Provide full width of ingress/egress area Figure 4.2 —Stabilized Construction Entrance February 2005 Volume 11—Construction Stormwater Pollution Prevention 4-9 BMP C120: Temporary and Permanent Seeding Pur��osc Seeding is intended to reduce erosion by stabilizing exposed soils. A well-established vegetative cover is one of the most effective methods of reducing erosion. Conditions of Use ' Seeding may be used throughout the project on disturbed areas that have reached final grade or that will remain unworked for more than 30 days. Channels that will be vegetated should be installed before major ` earthwork and hydroseeded with a Bonded Fiber Matrix. The vegetation should be well established(i.e., 75 percent cover)before water is allowed to flow in the ditch. With channels that will have high flows, erosion control blankets should be installed over the hydroseed. If vegetation cannot be established from seed before water is allowed in the ditch, sod should be installed in the bottom of the ditch over hydromulch and blankets. Retention/detention ponds should be seeded as required. Mulch is required at all times because it protects seeds from heat, moisture loss, and transport due to runoff. • All disturbed areas shall be reviewed in late August to early September and all seeding should be completed by the end of September. Otherwise,vegetation will not establish itself enough to provide more than average protection. • At final site stabilization, all disturbed areas not otherwise vegetated or stabilized shall be seeded and mulched. Final stabilization means the completion of all soil disturbing activities at the site and the establishment of a permanent vegetative cover, or equivalent permanent stabilization measures(such as pavement,riprap, gabions or geotextiles)which will prevent erosion. Design and • Seeding should be done during those seasons most conducive to Installation growth and will vary with the climate conditions of the region. Specifications Local experience should be used to determine the appropriate seeding periods. The optimum seeding windows for western Washington are April 1 through June 30 and September 1 through October 1. Seeding that occurs between July 1 and August 30 will require irrigation until 75 percent grass cover is established. Seeding that occurs between October 1 and March 30 will require a mulch or plastic cover until 75 percent grass cover is established. To prevent seed from being washed away, confirm that all required surface water control measures have been installed. February 2005 Volume 11—Construction Stormwater Pollution Prevention 4-13 • The seedbed should be firm and rough. All soil should be roughened no matter what the slope. If compaction is required for engineering purposes, slopes must be track walked before seeding. Backblading or smoothing of slopes greater than 4:1 is not allowed if they are to be seeded. • New and more effective restoration-based landscape practices rely on deeper incorporation than that provided by a simple single-pass rototilling treatment. Wherever practical the subgrade should be initially ripped to improve long-term permeability, infiltration,and water inflow qualities. At a minimum,permanent areas shall use soil amendments to achieve organic matter and permeability performance defined in engineered soil/landscape systems. For systems that are deeper than 8 inches the rototilling process should be done in multiple rh lifts, o the prepared soil system shall be prepared properly and then placed to achieve the specified depth. • Organic matter is the most appropriate form of"fertilizer"because it provides nutrients (including nitrogen,phosphorus,and potassium) in the least water-soluble form. A natural system typically releases 2-10 percent of its nutrients annually. Chemical fertilizers have since been formulated to simulate what organic matter does naturally. • In general, 10-4-6 N-P-K(nitrogen-phosphorus-potassium)fertilizer can be used at a rate of 90 pounds per acre. Slow-release fertilizers should always be used because they are more efficient and have fewer environmental impacts. It is recommended that areas being seeded for final landscaping conduct soil tests to determine the exact type and quantity of fertilizer needed. This will prevent the over-application of fertilizer. Fertilizer should not be added to the hydromulch machine and agitated more than 20 minutes before it is to be used. If agitated too much,the slow-release coating is destroyed. • There are numerous products available on the market that take the place of chemical fertilizers. These include several with seaweed extracts that are beneficial to soil microbes and organisms. If 100 percent cottonseed meal is used as the mulch in hydroseed, chemical fertilizer may not be necessary. Cottonseed meal is a good source of long-term, slow-release, available nitrogen. • Hydroseed applications shall include a minimum of 1,500 pounds per acre of mulch with 3 percent tackifier. Mulch may be made up of 100 percent: cottonseed meal; fibers made of wood,recycled cellulose, hemp, and kenaf; compost; or blends of these. Tackifier shall be plant- based, such as guar or alpha plantago, or chemical-based such as polyacrylamide or polymers. Any mulch or tackifier product used shall be installed per manufacturer's instructions. Generally,mulches come in 40-50 pound bags. Seed and fertilizer are added at time of application. 4-14 Volume 11—Construction Stormwater Pollution Prevention February 2005 • Mulch is always required for seeding. Mulch can be applied on top of the seed or simultaneously by hydroseeding. • On steep slopes, Bonded Fiber Matrix(BFM)or Mechanically Bonded Fiber Matrix (MBFM)products should be used. BFM/MBFM products are applied at a minimum rate of 3,000 pounds per acre of mulch with approximately 10 percent tackifier. Application is made so that a minimum of 95 percent soil coverage is achieved. Numerous products are available commercially and should be installed per manufacturer's instructions. Most products require 24-36 hours to cure before a rainfall and cannot be installed on wet or saturated soils. Generally,these products come in 40-50 pound bags and include all necessary ingredients except for seed and fertilizer. BFMs and MBFMs have some advantages over blankets: • No surface preparation required; • Can be installed via helicopter in remote areas; • On slopes steeper than 2.5:1,blanket installers may need to be roped and harnessed for safety; • They are at least$1,000 per acre cheaper installed. In most cases,the shear strength of blankets is not a factor when used on slopes, only when used in channels. BFMs and MBFMs are good alternatives to blankets in most situations where vegetation establishment is the goal. • When installing seed via hydroseeding operations, only about 1/3 of the seed actually ends up in contact with the soil surface. This reduces the ability to establish a good stand of grass quickly. One way to overcome this is to increase seed quantities by up to 50 percent. • Vegetation establishment can also be enhanced by dividing the hydromulch operation into two phases: 1. Phase l-Install all seed and fertilizer with 25-30 percent mulch and tackifier onto soil in the first lift; 2. Phase 2-Install the rest of the mulch and tackifier over the first lift. An alternative is to install the mulch, seed, fertilizer, and tackifier in one lift. Then, spread or blow straw over the top of the hydromulch at a rate of about 800-1000 pounds per acre. Hold straw in place with a standard tackifier. Both of these approaches will increase cost moderately but will greatly improve and enhance vegetative establishment. The increased cost may be offset by the reduced need for: 1. Irrigation 2. Reapplication of mulch 3. Repair of failed slope surfaces February 2005 Volume 11— Construction Stormwater Pollution Prevention 4-15 • This technique works with standard hydromulch(1,500 pounds per acre • minimum)and BFM/MBFMs (3,000 pounds per acre minimum). • Areas to be permanently landscaped shall provide a healthy topsoil that reduces the need for fertilizers, improves overall topsoil quality, provides for better vegetal health and vitality, improves hydrologic characteristics, and reduces the need for irrigation. This can be • accomplished in a number of ways: Recent research has shown that the best method to improve till soils is to amend these soils with compost. The optimum mixture is approximately two parts soil to one part compost. This equates to 4 inches of compost mixed to a depth of 12 inches in till soils. Increasing the concentration of compost beyond this level can have negative effects on vegetal health,while decreasing the concentrations can reduce the benefits of amended soils. Please note: The compost should meet specifications for Grade A quality compost in Ecology Publication 94-038. Other soils, such as gravel or cobble outwash soils,may require different approaches. Organics and fines easily migrate through the loose structure of these soils. Therefore,the importation of at least 6 inches of quality topsoil,underlain by some type of filter fabric to prevent the migration of fines,may be more appropriate for these soils. Areas that already have good topsoil, such as undisturbed areas,do not require soil amendments. • Areas that will be seeded only and not landscaped may need compost or meal-based mulch included in the hydroseed in order to establish vegetation. Native topsoil should be re-installed on the disturbed soil surface before application. • Seed that is installed as a temporary measure may be installed by hand if it will be covered by straw,mulch, or topsoil. Seed that is installed as a permanent measure may be installed by hand on small areas (usually less than 1 acre)that will be covered with mulch,topsoil, or erosion blankets. The seed mixes listed below include recommended mixes for both temporary and permanent seeding. These mixes,with the exception of the wetland mix, shall be applied at a rate of 120 pounds per acre. This rate can be reduced if soil amendments or slow- release fertilizers are used. Local suppliers or the local conservation district should be consulted for their recommendations because the appropriate mix depends on a variety of factors, including location, exposure, soil type, slope, and expected foot traffic. Alternative seed mixes approved by the local authority may be used. 4-16 Volume 11—Construction Stormwater Pollution Prevention February 2005 _ Table 4.1 represents the standard mix for those areas where just a temporary vegetative cover is required. Table 4.1 Temporary Erosion Control Seed Mix %Weight %Puri %Germination Chewings or annual blue grass 40 98 90 Festuca rubra var. commutata or Poa anna Perennial rye- 50 98 90 Lolium perenne Redtop or colonial bentgrass 5 92 85 A rostis alba or Agrostis tenuis White dutch clover 5 98 90 Tri olium re ens Table 4.2 provides just one recommended possibility for landscaping seed. Table 4.2 Landscaping Seed Mix %Weight %Puri %Germination Perennial rye blend 70 98 90 Lolium perenne Chewings and red fescue blend 30 98 90 Festuca rubra var. commutata or Festuca rubra This turf seed mix in Table 4.3 is for dry situations where there is no need for much water. The advantage is that this mix requires very little maintenance. Table 4.3 Low-Growing Turf Seed Mix % Weight %Puri %Germination Dwarf tall fescue(several varieties) 45 98 90 Festuca arundinacea var. Dwarf perennial rye(Barclay) 30 98 90 Lolium perenne var. barclay Red fescue 20 98 90 Festuca rubra Colonial bentgrass 5 98 90 Agrostis tenuis Table 4.4 presents a mix recommended for bioswales and other intermittently wet areas. Table 4.4 Bioswale Seed Mix* %Weight %Puri %Germination Tall or meadow fescue 75-80 98 90 Festuca arundinacea or Festuca elation Seaside/Creeping bentgrass 10-15 92 85 A rostis palustris Redtop bentgrass 5-10 90 80 Agrostis alba or A rostis gigantea *Modified Briargreen,Inc.Hydroseeding Guide Wetlands Seed Mix February 2005 Volume 11—Construction Stormwater Pollution Prevention 4-17 The seed mix shown in Table 4.5 is a recommended low-growing, relatively non-invasive seed mix appropriate for very wet areas that are not regulated wetlands. Other mixes may be appropriate, depending on the soil type and hydrology of the area. Recent research suggests that bentgrass(agrostis sp.) should be emphasized in wet-area seed mixes. Apply this mixture at a rate of 60 pounds per acre. Table 4.5 Wet Area Seed Mix* %Wei ght %Puri %Germination Tall or meadow fescue 60-70 98 90 Festuca arundinacea or Festuca elatior Seaside/Creeping bentgrass 10-15 98 85 A rostis palustris Meadow foxtail 10-15 90 80 Ale ocurus pratensis Alsike clover 1-6 98 90 Tri olium hybridum Redtop bentgrass 1-6 92 85 Agrostis alba *Modified Briargreen, Inc. Hydroseeding Guide Wetlands Seed Mix The meadow seed mix in Table 4.6 is recommended for areas that will be maintained infrequently or not at all and where colonization by native plants is desirable. Likely applications include rural road and utility right- of-way. Seeding should take place in September or very early October in order to obtain adequate establishment prior to the winter months. The appropriateness of clover in the mix may need to be considered,as this can be a fairly invasive species. If the soil is amended,the addition of clover may not be necessary. Table 4.6 Meadow Seed Mix %Weight %Puri %Germination Redtop or Oregon bentgrass 20 92 85 Agrostis alba or A rostis ore onensis Red fescue 70 98 90 Festuca rubra White dutch clover 10 98 90 Tri olium re ens Maintenance • Any seeded areas that fail to establish at least 80 percent cover(100 Standards percent cover for areas that receive sheet or concentrated flows) shall be reseeded. If reseeding is ineffective,an alternate method, such as sodding, mulching, or nets/blankets, shall be used. If winter weather prevents adequate grass growth,this time limit may be relaxed at the discretion of the local authority when sensitive areas would otherwise be protected. 4-18 Volume 11—Construction Stotmwater Pollution Prevention February 2005 After adequate cover is achieved, any areas that experience erosion shall be reseeded and protected by mulch. If the erosion problem is drainage related,the problem shall be fixed and the eroded area reseeded and protected by mulch. • Seeded areas shall be supplied with adequate moisture,but not watered to the extent that it causes runoff. February 2005 Volume 11— Construction Stormwater Pollution Prevention 4-19 BMP C121: Mulching Purpose The purpose of mulching soils is to provide immediate temporary protection from erosion. Mulch also enhances plant establishment by conserving moisture, holding fertilizer, seed, and topsoil in place,and moderating soil temperatures. There is an enormous variety of mulches that can be used. Only the most common types are discussed in this section. Conditions of Use As a temporary cover measure, mulch should be used: • On disturbed areas that require cover measures for less than 30 days. • As a cover for seed during the wet season and during the hot summer months. • During the wet season on slopes steeper than 3H:1 V with more than 10 feet of vertical relief. Mulch may be applied at any time of the year and must be refreshed periodically. Design and For mulch materials, application rates, and specifications, see Table 4.7. Installation Note: Thicknesses may be increased for disturbed areas in or near Specifications sensitive areas or other areas highly susceptible to erosion. Mulch used within the ordinary high-water mark of surface waters should be selected to minimize potential flotation of organic matter. Compcisted organic materials have higher specific gravities (densities)than straw, wood, or chipped material. Maintenance • The thickness of the cover must be maintained. Standards • Any areas that experience erosion shall be remulched and/or protected with a net or blanket. If the erosion problem is drainage related,then the problem shall be fixed and the eroded area remulched. 4-20 Volume 11—Construction Stormwater Pollution Prevention February 2005 Table 4.7 Mulch Standards and Guidelines Mulch Application Material Quality Standards Rates Remarks Straw Air-dried;free from 2"-3"thick;5 Cost-effective protection when applied with adequate undesirable seed and bales per 1000 sf thickness. Hand-application generally requires greater coarse material. or 2-3 tons per thickness than blown straw.The thickness of straw may be acre reduced by half when used in conjunction with seeding. In windy areas straw must be held in place by crimping,using a tackifier,or covering with netting. Blown straw always has to be held in place with a tackifier as even light winds will blow it away.Straw,however,has several deficiencies that should be considered when selecting mulch materials.It often introduces and/or encourages the propagation of weed species and it has no significant long-term benefits. Straw should be used only if mulches with long-term benefits are unavailable locally. It should also not be used within the ordinary high-water elevation of surface waters(due to flotation). Hydromulch No growth Approx.25-30 Shall be applied with hydromulcher. Shall not be used inhibiting factors. lbs per 1000 sf without seed and tackifier unless the application rate is at or 1500 -2000 least doubled. Fibers longer than about%-1 inch clog lbs per acre hydromulch equipment. Fibers should be kept to less than'/4 inch. Composted No visible water or 2"thick min.; More effective control can be obtained by increasing Mulch and dust during approx. 100 tons thickness to 3". Excellent mulch for protecting final grades Compost handling. Must be per acre(approx. until landscaping because it can be directly seeded or tilled purchased from 800 lbs per yard) into soil as an amendment. Composted mulch has a coarser supplier with Solid size gradation than compost.It is more stable and practical Waste Handling to use in wet areas and during rainy weather conditions. Permit(unless exempt). Chipped Site Average size shall 2"minimum This is a cost-effective way to dispose of debris from Vegetation be several inches. thickness clearing and grubbing,and it eliminates the problems Gradations from associated with burning. Generally,it should not be used on fines to 6 inches in slopes above approx. 10%because of its tendency to be length for texture, transported by runoff. It is not recommended within 200 variation,and feet of surface waters. If seeding is expected shortly after interlocking mulch,the decomposition of the chipped vegetation may tie properties. up nutrients important to grass establishment. Wood-based No visible water or 2"thick;approx. This material is often called"hog or hogged fuel." It is Mulch dust during 100 tons per acre usable as a material for Stabilized Construction Entrances handling. Must be (approx.800 lbs. (BMP C 105)and as a mulch. The use of mulch ultimately purchased from a per cubic yard) improves the organic matter in the soil. Special caution is supplier with a Solid advised regarding the source and composition of wood- Waste Handling based mulches. Its preparation typically does not provide Permit or one any weed seed control,so evidence of residual vegetation in exempt from solid its composition or known inclusion of weed plants or seeds waste regulations. should be monitored and prevented(or minimized). February 2005 Volume 11—Construction Stormwater Pollution Prevention 4-21 BMP C123: Plastic Covering Purpose Plastic covering provides immediate, short-term erosion protection to slopes and disturbed areas. Conditions of • Plastic covering may be used on disturbed areas that require cover Use measures for less than 30 days, except as stated below. • Plastic is particularly useful for protecting cut and fill slopes and stockpiles. Note: The relatively rapid breakdown of most polyethylene sheeting makes it unsuitable for long-term(greater than six months) pp ca a li tions. � • Clear plastic sheeting can be used over newly-seeded areas to create a p g Y greenhouse effect and encourage grass growth if the hydroseed was installed too late in the season to establish 75 percent grass cover, or if the wet season started earlier than normal. Clear plastic should not be used for this purpose during the summer months because the resulting high temperatures can kill the grass. • Due to rapid runoff caused by plastic sheeting,this method shall not be used upslope of areas that might be adversely impacted by concentrated runoff. Such areas include steep and/or unstable slopes. • While plastic is inexpensive to purchase,the added cost of installation, maintenance,removal,and disposal make this an expensive material, up to $1.50-2.00 per square yard. • Whenever plastic is used to protect slopes,water collection measures must be installed at the base of the slope. These measures include plastic-covered berms,channels, and pipes used to covey clean rainwater away from bare soil and disturbed areas. At no time is clean runoff from a plastic covered slope to be mixed with dirty runoff from a project. • Other uses for plastic include: 1. Temporary ditch liner; 2. Pond liner in temporary sediment pond; 3. Liner for bermed temporary fuel storage area if plastic is not reactive to the type of fuel being stored; 4. Emergency slope protection during heavy rains; and, 5. Temporary drainpipe("elephant trunk") used to direct water. 4-26 Volume 11—Construction Stormwater Pollution Prevention February 2005 Design and Plastic slope cover must be installed as follows: Installation 1. Run plastic up and down slope, not across slope; Specifications 2. Plastic may be installed perpendicular to a slope if the slope length is less than 10 feet; 3. Minimum of 8-inch overlap at seams; 4. On long or wide slopes, or slopes subject to wind, all seams should be taped; 5. Place plastic into a small (I 2-inchwide by 6-inch deep) slot trench at the top of the slope and backfill with soil to keep water from flowing underneath; 6. Place sand filled burlap or geotextile bags every 3 to 6 feet along seams and pound a wooden stake through each to hold them in place; 7. Inspect plastic for rips,tears, and open seams regularly and repair immediately. This prevents high velocity runoff from contacting bare soil which causes extreme erosion; 8. Sandbags may be lowered into place tied to ropes. However, all sandbags must be staked in place. • Plastic sheeting shall have a minimum thickness of 0.06 millimeters. • If erosion at the toe of a slope is likely, a gravel berm, riprap, or other suitable protection shall be installed at the toe of the slope in order to reduce the velocity of runoff. Maintenance • Torn sheets must be replaced and open seams repaired. Standards • If the plastic begins to deteriorate due to ultraviolet radiation, it must be completely removed and replaced. • When the plastic is no longer needed, it shall be completely removed. • Dispose of old tires appropriately. February 2005 Volume II—Construction Stormwater Pollution Prevention 4-27 BMP C124: Sodding Purpose The purpose of sodding is to establish permanent turf for immediate erosion protection and to stabilize drainage ways where concentrated overland flow will occur. Conditions of Use Sodding may be used in the following areas: • Disturbed areas that require short-term or long-term cover. Disturbed areas that require immediate vegetative cover. All waterways that require vegetative lining. Waterways may also be seeded rather than sodded, and protected with a net or blanket. Design and Sod shall be free of weeds,of uniform thickness (approximately 1-inch Installation thick), and shall have a dense root mat for mechanical strength. Specifications The following steps are recommended for sod installation: • Shape and smooth the surface to final grade in accordance with the approved grading plan. The swale needs to be overexcavated 4 to 6 inches below design elevation to allow room for placing soil amendment and sod. • Amend 4 inches(minimum)of compost into the top 8 inches of the soil if the organic content of the soil is less than ten percent or the permeability is less than 0.6 inches per hour. Compost used should meet Ecology publication 94-038 specifications for Grade A quality compost. • Fertilize according to the supplier's recommendations. • Work lime and fertilizer 1 to 2 inches into the soil, and smooth the surface. • Lay strips of sod beginning at the lowest area to be sodded and perpendicular to the direction of water flow. Wedge strips securely into place. Square the ends of each strip to provide for a close,tight fit. Stagger joints at least 12 inches. Staple on slopes steeper than 3H:1 V. Staple the upstream edge of each sod strip. • Roll the sodded area and irrigate. • When sodding is carried out in alternating strips or other patterns, seed the areas between the sod immediately after sodding. Maintenance If the grass is unhealthy,the cause shall be determined and appropriate Standards action taken to reestablish a healthy groundcover. If it is impossible to establish a healthy groundcover due to frequent saturation, instability,or some other cause,the sod shall be removed,the area seeded with an appropriate mix, and protected with a net or blanket. 4-28 Volume 11—Construction Stormwater Pollution Prevention February 2005 BMP C130: Surface Roughening Purpose Surface roughening aids in the establishment of vegetative cover, reduces runoff velocity, increases infiltration, and provides for sediment trapping through the provision of a rough soil surface. Horizontal depressions are created by operating a tiller or other suitable equipment on the contour or by leaving slopes in a roughened condition by not fine grading them. Conditions for • All slopes steeper than 3:1 and greater than 5 vertical feet require Use surface roughening. • Areas with grades steeper than 3:1 should be roughened to a depth of 2 to 4 inches prior to seeding. • Areas that will not be stabilized immediately may be roughened to reduce runoff velocity until seeding takes place. • Slopes with a stable rock face do not require roughening. • Slopes where mowing is planned should not be excessively roughened. Design and There are different methods for achieving a roughened soil surface on a Installation slope, and the selection of an appropriate method depends upon the type of Specifications slope. Roughening methods include stair-step grading, grooving, contour furrows, and tracking. See Figure 4.6 for tracking and contour furrows. Factors to be considered in choosing a method are slope steepness,mowing requirements, and whether the slope is formed by cutting or filling. • Disturbed areas that will not require mowing may be stair-step graded, grooved, or left rough after filling. • Stair-step grading is particularly appropriate in soils containing large amounts of soft rock. Each "step"catches material that sloughs from above, and provides a level site where vegetation can become established. Stairs should be wide enough to work with standard earth moving equipment. Stair steps must be on contour or gullies will form on the slope. • Areas that will be mowed(these areas should have slopes less steep than 3:1)may have small furrows left by disking, harrowing, raking, or seed-planting machinery operated on the contour. • Graded areas with slopes greater than 3:1 but less than 2:1 should be roughened before seeding. This can be accomplished in a variety of ways, including "track walking," or driving a crawler tractor up and down the slope, leaving a pattern of cleat imprints parallel to slope contours. • Tracking is done by operating equipment up and down the slope to leave horizontal depressions in the soil. Maintenance • Areas that are graded in this manner should be seeded as quickly as Standards possible. • Regular inspections should be made of the area. If rills appear,they should be re-graded and re-seeded immediately. 4-36 Volume 11— Construction Stormwater Pollution Prevention February 2005 Tracking oO y Q G 'TRACKING'with machinery up and down a the slope provides grooves that will catch seed, rainfall and reduce runoff. \ `� Contour Furrows \ 1( 5 6" m i n �\ \ (150mm) 3 Maximum 1 Grooves Will Catch Seed Fand' II Dec ease Runoff. \\\�\\\ \�\\ � Figure 4.6—Surface Roughening by Tracking and Contour Furrows February 2005 Volume 11— Construction Stormwater Pollution Prevention 4-37 BMP C202: Channel Lining Purpose To protect erodible channels by providing a channel liner using either blankets or riprap. Conditions of Use When natural soils or vegetated stabilized soils in a channel are not adequate to prevent channel erosion. • When a permanent ditch or pipe system is to be installed and a temporary measure is needed. In almost all cases, synthetic and organic coconut blankets are more effective than riprap for protecting channels from erosion. Blankets can be used with and without vegetation. Blanketed channels can be designed to handle any expected flow and longevity requirement. Some synthetic blankets have a predicted life span of 50 years or more, even in sunlight. Other reasons why blankets are better than rock include the availability of blankets over rock. In many areas of the state, rock is not easily obtainable or is very expensive to haul to a site. Blankets can be delivered anywhere. Rock requires the use of dump trucks to haul and heavy equipment to place. Blankets usually only require laborers with hand tools, and sometimes a backhoe. The Federal Highway Administration recommends not using flexible liners whenever the slope exceeds 10 percent or the shear stress exceeds 8 lbs/ft2. Design and See BMP C 122 for information on blankets. Installation Since riprap is used where erosion potential is high, construction must be Specifications sequenced so that the riprap is put in place with the minimum possible delay. • Disturbance of areas where riprap is to be placed should be undertaken only when final preparation and placement of the riprap can follow immediately behind the initial disturbance. Where riprap is used for outlet protection,the riprap should be placed before or in conjunction with the construction of the pipe or channel so that it is in place when the pipe or channel begins to operate. • The designer, after determining the riprap size that will be stable under the flow conditions, shall consider that size to be a minimum size and then,based on riprap gradations actually available in the area, select the size or sizes that equal or exceed the minimum size. The possibility of drainage structure damage by children shall be considered in selecting a riprap size, especially if there is nearby water or a gully in which to toss the stones. • Stone for riprap shall consist of field stone or quarry stone of approximately rectangular shape. The stone shall be hard and angular and of such quality that it will not disintegrate on exposure to water or February 2005 Volume 11—Construction Stormwater Pollution Prevention 4-63 weathering and it shall be suitable in all respects for the purpose intended. • Rubble concrete may be used provided it has a density of at least 150 pounds per cubic foot,and otherwise meets the requirement of this standard and specification. • A lining of engineering filter fabric (geotextile) shall be placed between the riprap and the underlying soil surface to prevent soil movement into or through the riprap. The geotextile should be keyed in at the top of the bank. • Filter fabric shall not be used on slopes greater than 1-1/2:1 as slippage may occur. It should be used in conjunction with a layer of coarse aggregate(granular filter blanket)when the riprap to be placed is 12 inches and larger. 4-64 Volume 11— Construction Stormwater Pollution Prevention February 2005 BMP C207: Check Dams Purpose Construction of small dams across a swale or ditch reduces the velocity of concentrated flow and dissipates energy at the check dam. Conditions of Use Where temporary channels or permanent channels are not yet vegetated, channel lining is infeasible, and velocity checks are required. ' • Check dams may not be placed in streams unless approved by the State Department of Fish and Wildlife. Check dams may not be placed in wetlands without approval from a permitting agency. • Check dams shall not be placed below the expected backwater from any salmonid bearing water between October 1 and May 31 to ensure that there is no loss of high flow refuge habitat for overwintering juvenile salmonids and emergent salmonid fry. Design and Whatever material is used,the dam should form a triangle when viewed Installation from the side. This prevents undercutting as water flows over the face of Specifications the dam rather than falling directly onto the ditch bottom. Check dams in association with sumps work more effectively at slowing flow and retaining sediment than just a check dam alone. A deep sump should be provided immediately upstream of the check dam. • In some cases, if carefully located and designed, check dams can remain as permanent installations with very minor regrading. They may be left as either spillways, in which case accumulated sediment would be graded and seeded, or as check dams to prevent further sediment from leaving the site. • Check dams can be constructed of either rock or pea-gravel filled bags. Numerous new products are also available for this purpose. They tend to be re-usable, quick and easy to install, effective,and cost efficient. • Check dams should be placed perpendicular to the flow of water. • The maximum spacing between the dams shall be such that the toe of the upstream dam is at the same elevation as the top of the downstream dam. • Keep the maximum height at 2 feet at the center of the dam. • Keep the center of the check dam at least 12 inches lower than the outer edges at natural ground elevation. • Keep the side slopes of the check dam at 2:1 or flatter. • Key the stone into the ditch banks and extend it beyond the abutments a minimum of 18 inches to avoid washouts from overflow around the dam. February 2005 Volume 11—Construction Stormwater Pollution Prevention 4-75 • • Use filter fabric foundation under a rock or sand bag check dam. If a blanket ditch liner is used,this is not necessary. A piece of organic or • synthetic blanket cut to fit will also work for this purpose. • Rock check dams shall be constructed of appropriately sized rock. The rock must be placed by hand or by mechanical means(no • dumping of rock to form dam)to achieve complete coverage of the ditch or swale and to ensure that the center of the dam is lower than the edges. The rock used must be large enough to stay in place given • the expected design flow through the channel. • In the case of grass-lined ditches and swales, all check dams and accumulated sediment shall be removed when the grass has matured sufficiently to protect the ditch or swale-unless the slope of the Swale is greater than 4 percent. The area beneath the check dams shall be seeded and mulched immediately after dam removal. • Ensure that channel appurtenances, such as culvert entrances below check dams, are not subject to damage or blockage from displaced stones. Figure 4.13 depicts a typical rock check dam. Maintenance Check dams shall be monitored for performance and sediment Standards accumulation during and after each runoff producing rainfall. Sediment shall be removed when it reaches one half the sump depth. • Anticipate submergence and deposition above the check dam and erosion from high flows around the edges of the dam. • If significant erosion occurs between dams, install a protective riprap liner in that portion of the channel. 4-76 Volume 11— Construction Stormwater Pollution Prevention February 2005 View Looking Upstream 18"(0.5m) A • 12" (150mm) ° $1 � 24"(0.6m) off° o o o.°� NOTE\ oo�v • Q co0� o o O o o° / % Key stone into channel banks and extend it beyond the abutments a minimum of 18" (0.5m)to prevent LA flow around dam. Section A - A FLOW �— 24" (0.6m) 8'(2.4m) Spacing Between Check Dams 'L'=the distance such that points'A'and 'B'are of equal elevation. L' POINT'B' POINT'A' NOT TO SCALE Figure 4.13—Check Dams February 2005 Volume 11—Construction Stormwater Pollution Prevention 4-77 BMP C233: Silt Fence Purpose Use of a silt fence reduces the transport of coarse sediment from a construction site by providing a temporary physical barrier to sediment and reducing the runoff velocities of overland flow. See Figure 4.19 for • details on silt fence construction. Conditions of Use Silt fence may be used downslope of all disturbed areas. • Silt fence is not intended to treat concentrated flows, nor is it intended to treat substantial amounts of overland flow. Any concentrated flows must be conveyed through the drainage system to a sediment pond. The only circumstance in which overland flow can be treated solely by a silt fence,rather than by a sediment pond, is when the area draining to the fence is one acre or less and flow rates are less than 0.5 cfs. • Silt fences should not be constructed in streams or used in V-shaped ditches. They are not an adequate method of silt control for anything deeper than sheet or overland flow. Joints in filter fabric shall be spliced at posts.Use staples,wire rings or 2"x2' by 14 Ga.wire or equivalent to attach fabric to posts equivalent, if standard strength fabric used 1. Filter fabric c fV _ I-,I Ii I _T 111 I f ( -1Ti-1 I► 6'maxim T.....:::,:-Minimum 4"x4"trench -I E L Backfill trench with native soil Post spacing may be increased or 3/4"-1.5"washed gravel to 8'if wire backing is used 2"x2"wood posts,steel fence posts,or equivalent Figure 4.19—Silt Fence Design and • Drainage area of 1 acre or less or in combination with sediment basin Installation in a larger site. Specifications • Maximum slope steepness (normal (perpendicular)to fence line) 1:1. • Maximum sheet or overland flow path length to the fence of 100 feet. No flows greater than 0.5 cfs. • The geotextile used shall meet the following standards. All geotextile properties listed below are minimum average roll values(i.e.,the test result for any sampled roll in a lot shall meet or exceed the values shown in Table 4.10): 4-94 Volume 11— Construction Stormwater Pollution Prevention February 2005 Table 4.10 Geotextile Standards Polymeric Mesh AOS 0.60 mm maximum for slit film wovens(#30 sieve). 0.30 (ASTM D4751) mm maximum for all other geotextile types(#50 sieve). 0.15 mm minimum for all fabric types(#100 sieve). Water Permittivity 0.02 sec-1 minimum (ASTM D4491) Grab Tensile Strength 180 lbs.Minimum for extra strength fabric. (ASTM D4632) 100 lbs minimum for standard strength fabric. Grab Tensile Strength 30%maximum (ASTM D4632) Ultraviolet Resistance 70%minimum (ASTM D4355) • Standard strength fabrics shall be supported with wire mesh, chicken wire,2-inch x 2-inch wire, safety fence, or jute mesh to increase the strength of the fabric. Silt fence materials are available that have synthetic mesh backing attached. • Filter fabric material shall contain ultraviolet ray inhibitors and stabilizers to provide a minimum of six months of expected usable construction life at a temperature range of 0°F.to 120°F. • 100 percent biodegradable silt fence is available that is strong, long lasting,and can be left in place after the project is completed, if permitted by local regulations. • Standard Notes for construction plans and specifications follow. Refer to Figure 4.19 for standard silt fence details. The contractor shall install and maintain temporary silt fences at the locations shown in the Plans. The silt fences shall be constructed in the areas of clearing, grading, or drainage prior to starting those activities. A silt fence shall not be considered temporary if the silt fence must function beyond the life of the contract. The silt fence shall prevent soil carried by runoff water from going beneath,through, or over the top of the silt fence,but shall allow the water to pass through the fence. The minimum height of the top of silt fence shall be 2 feet and the maximum height shall be 2%feet above the original ground surface. The geotextile shall be sewn together at the point of manufacture, or at an approved location as determined by the Engineer,to form geotextile lengths as required. All sewn seams shall be located at a support post. Alternatively,two sections of silt fence can be overlapped,provided the Contractor can demonstrate,to the satisfaction of the Engineer,that the overlap is long enough and that the adjacent fence sections are close enough together to prevent silt laden water from escaping through the fence at the overlap. February 2005 Volume 11— Construction Stormwater Pollution Prevention 4-95 The geotextile shall be attached on the up-slope side of the posts and • support system with staples,wire,or in accordance with the • manufacturer's recommendations. The geotextile shall be attached to the posts in a manner that reduces the potential for geotextile tearing at the staples,wire, or other connection device. Silt fence back-up • support for the geotextile in the form of a wire or plastic mesh is dependent on the properties of the geotextile selected for use. If wire • or plastic back-up mesh is used,the mesh shall be fastened securely to • the up-slope of the posts with the geotextile being up-slope of the mesh back-up support. The geotextile at the bottom of the fence shall be buried in a trench to a minimum depth of 4 inches below the ground surface. The trench shall be backfilled and the soil tamped in place over the buried portion of the geotextile, such that no flow can pass beneath the fence and scouring can not occur. When wire or polymeric back-up support mesh is used,the wire or polymeric mesh shall extend into the trench a minimum of 3 inches. The fence posts shall be placed or driven a minimum of 18 inches. A minimum depth of 12 inches is allowed if topsoil or other soft subgrade soil is not present and a minimum depth of 18 inches cannot be reached. Fence post depths shall be increased by 6 inches if the fence is located on slopes of 3:1 or steeper and the slope is perpendicular to the fence. If required post depths cannot be obtained, the posts shall be adequately secured by bracing or guying to prevent overturning of the fence due to sediment loading. Silt fences shall be located on contour as much as possible, except at the ends of the fence,where the fence shall be turned uphill such that the silt fence captures the runoff water and prevents water from flowing around the end of the fence. If the fence must cross contours,with the exception of the ends of the fence, gravel check dams placed perpendicular to the back of the fence shall be used to minimize concentrated flow and erosion along the back of the fence. The gravel check dams shall be approximately 1- foot deep at the back of the fence. It shall be continued perpendicular to the fence at the same elevation until the top of the check dam intercepts the ground surface behind the fence. The gravel check dams shall consist of crushed surfacing base course, gravel backfill for walls,or shoulder ballast. The gravel check dams shall be located every 10 feet along the fence where the fence must cross contours. The slope of the fence line where contours must be crossed shall not be steeper than 3:1. Wood, steel or equivalent posts shall be used. Wood posts shall have minimum dimensions of 2 inches by 2 inches by 3 feet minimum length, and shall be free of defects such as knots, splits, or gouges. 4-96 Volume 11— Construction StormwaterPollution Prevention February 2005 a Steel posts shall consist of either size No. 6 rebar or larger,ASTM A 120 steel pipe with a minimum diameter of 1-inch, U, T, L, or C shape • steel posts with a minimum weight of 1.35 lbs./ft. or other steel posts having equivalent strength and bending resistance to the post sizes listed. The spacing of the support posts shall be a maximum of 6 feet. • Fence back-up support, if used, shall consist of steel wire with a maximum mesh spacing of 2 inches,or a prefabricated polymeric mesh. The strength of the wire or polymeric mesh shall be equivalent to or greater than 180 lbs. grab tensile strength. The polymeric mesh must be as resistant to ultraviolet radiation as the geotextile it supports. • Silt fence installation using the slicing method specification details follow. Refer to Figure 4.20 for slicing method details. The base of both end posts must be at least 2 to 4 inches above the top of the silt fence fabric on the middle posts for ditch checks to drain properly. Use a hand level or string level, if necessary,to mark base points before installation. Install posts 3 to 4 feet apart in critical retention areas and 6 to 7 feet apart in standard applications. Install posts 24 inches deep on the downstream side of the silt fence, and as close as possible to the fabric, enabling posts to support the fabric from upstream water pressure. Install posts with the nipples facing away from the silt fence fabric. Attach the fabric to each post with three ties, all spaced within the top 8 inches of the fabric. Attach each tie diagonally 45 degrees through the fabric,with each puncture at least 1 inch vertically apart. In addition, each tie should be positioned to hang on a post nipple when tightening to prevent sagging. Wrap approximately 6 inches of fabric around the end posts and secure with 3 ties. No more than 24 inches of a 36-inch fabric is allowed above ground level. The rope lock system must be used in all ditch check applications. The installation should be checked and corrected for any deviation before compaction. Use a flat-bladed shovel to tuck fabric deeper into the ground if necessary. Compaction is vitally important for effective results. Compact the soil immediately next to the silt fence fabric with the front wheel of the tractor, skid steer, or roller exerting at least 60 pounds per square inch. Compact the upstream side first and then each side twice for a total of four trips. February 2005 Volume 11— Construction Stormwater Pollution Prevention 4-97 • Any damage shall be repaired immediately. Maintenance If concentrated flows are evident uphill of the fence,they must be • Standards intercepted and conveyed to a sediment pond. It is important to check the uphill side of the fence for signs of the fence clogging and acting as a barrier to flow and then causing channelization of flows parallel to the fence. If this occurs,replace the fence or remove the trapped sediment. • Sediment deposits shall either be removed when the deposit reaches approximately one-third the height of the silt fence, or a second silt fence shall be installed. If the filter fabric (geotextile)has deteriorated due to ultraviolet breakdown, it shall be replaced. Pondmg height POST SPACING: max.24- 7'max.on open runs .............. ...................6 of Fabric T 4'max.on pooling areas I} 17777 Attach fabric to upstream side of post 8• FLOW — orive o.e.each aria o1 POST DEPTH: .ut rent.2 to 4 emes Ae mu,h below ground with deelee exerting as fabric above ground p P.s.l.a►greeter ismewapc"4 100%comp"U'r, "attach t V�\�/\ ATTACHMEW DETAILS: \\ a Gather fabric at posts,IT needed. RIN\\\\\ \�/�\/�\ �\ •Utilize Wee lies per post.al within top B'of fabric. �% �i\��% \���i��i�\ •positionnvninern on each tie diagonally.puncturing holes vertically \\\\\\ \\\ \\\\\\\\\ a or 1'e e Hang each tie on a post nipple and tighten securely. No more than 24"of a 36"fabric the cable ties(50"or sat wie. is allowed above ground. Roll of sift fence .0- Opgration Post installed after compaction Fabric O above Silt Fence ground "—� r710.0n t� Zs Horizontal chisel point Slicing blade (76 mm width) (18 mm width) Completed Installation Vibratory plow is not acceptable because of horizontal compaction Figure 4.20—Silt Fence Installation by Slicing Method 4-98 Volume ll— Construction Stormwater Pollution Prevention February 2005 tJ 1 C� 2 0 J-/ t rtisF - r She — ' o cn t / /�, /� �o � / O , '� ells 1 Q C.0 � 7 r °V l All American Gcotechnical,Inc. project Drawn By: Proposed Developed Portion of Parcel Permit Numbs Parcel Number. 22230�000, 2230-23-D0010, lNTr 8947 Buttonwood Lane NE Number~ BWJ 2/18/20 Proposed Single Family Home Olympia, ly pia,Washington shingtcc 985 6, AAG2 i-V�5 2R�g� UNOr4 Washington Applicant Name:Brian Stebako Site Address: 11510 East State Route 6 2 a Inset REVIEWED FOR CODE COMPLIANCE roe MASON COUNTY RECEIVED BUILDING DEPARTMENT CLEARING NOV 19 2020 615 W. Alder Street o° DRIVE ti EXT SHED -/ 1 \ -- POSSIBLE WELL LOCATION GRAVITY DRAINFIELD SEASONALSTREAM SEPTIC TANK _ , 100'R \ 0 o o \ N BUILDING SITE cn cli 22230-24-00000 SITE PLAN: FOR: STEFANKO JOB#: PARCEL#: DATE: 10 AUGUST 2020 NGBY: TJS DESIGN PAGE OF NORTH ARROW: SCALE: 1"= 300' 0. 600- © B-LINE CONSTRUCTION INC. 1 r � � • r n RECEIVED --"/—Contour line adjustment ,f F r NOV 19 2020 -driveway grading complete,house site needs graded _ Alder Street ♦ Stream—designated as fish stream by DNR 615 W. -seasonal (dried out during JJAS) � Seasonal Stream on maps -none observed throughout the year ` Agricultural/storage building(288 sq ft footprint) (Affidavit of Exemption submitted) — f Building sire(3024 sq ft footprint) " Fiber and Electrical runs(vault and transformer marked) Proposed Well location ; Proposed Septic(Gravity)Drain field ` O Forested ` Cleared ;' • 1:3,Oe3 0 0M 0-05 0.1 ml • 0 0." 0-W ms km ..o�..�....._ a U. Not to scale REVIEWED FOR CODE COMPLIANCE MASON COUNTY BUILDING DEPARTMENT RECEIVED NOV 19 2020 z 3 615 W. Alder Street 22230 -21- 00021 -- E/au s - —5 Seasonal Stream Shed riveway , Septic —175'1 drain •. field Transformer - . well 22230 -23- REVIEWED FOR 00010 —100' radius :' CODE COMPLIANCE MASON COUNTY BUILDING DEPARTMENT Site Plan- 11510 E SR 106 — Stefa n ko 22230-24-00000 23 Oct 2020 Cleared Area Utilities Contours at 20' N Foo Tr it a i Home Site 240' AS L - Hill Slope approximate - Stormwater Engineering plan will be adhered to Road Cross section —190' ASL. Drainage Ditch/ Road Cross Sec ' ® Swale —150' ASL Cut Pasture Area 100' ASL Fill REVIEWED FOR ASL = Above Sea Level CODE COMPLIANCE MASON COON rY BUILDING DEPARTMENT NEW SINGLE FAMIL Y RESIDENCI�HESE PLANS MUST BE ON THE JOB SITE 11510 EAST STATE ROUTE 106, UNION, WA FOR INSPECTION PROJECT INFORMATION o R E E \ OWNER SITE LOCATION ' BRIAN STEFANKO SEC:30 T.-22 N R:2 W ` 4775 NE LAMMS LANE POOL SBO, WA 98370 PARCEL NOS brian.stefanko@gmaiLcom 222302100021 Y V 222302300010 N CIVIL ENGINEER 222302400000 1 M C N KYLE FREEMAN,P.E. D JURISDICTIONVECTOR ENGINEERING, INC D N 2724 BLACK LAKE BL VD SW MASON COUNTY F TUM WATER, WA 98512 PHONE., (360)352-2477 kfreeman@vectorengineeringinc.com ' \ GEOTECHNICAL F CURTIS D. CUSHMAN, E.G. ALL AMERICAN GEOTECHNICAL, INC j 8947 BUTTONWOOD LANE NE OL YMPIA, WA 98516 PHONE: (360)491-5155 0000 W Curtis.Cushman@comcast.net \ sp 4 ROAD DESIGN CRITERIA MINIMUM ROAD WIDTH=12' p MAXIMUM ROAD GRADE= 14 MIN/MUM TURNING RADIUS=25 ft(INSIDE)/45 ft(OUTSIDE) cr FIRE APPARATUS TURNOUTS=8 It(W)x 30 ft(L)w/TAPERS AND 150 ft ON CENTER. / sr S7S ys FIRE APPARATUS TURNAROUND=HAMMERHEAD, G s cq o 2s p CUL-DE-SAC, OR MODIFIED HAMMERHEAD TURNAROUND, MEETING MASON COUNTY BUILDING CODE CH. 14.17 DIMENSIONS,AND NOT MORE THAN 150 ft FROM THE STRUCTURE BEING SERVED. ALTERNA HOUSE "NOTE: THE ROAD LAYOUT,AS SHOWN IN THESE LOCATION& IVEWAY DRAWINGS, MAYBE FIELD-ADJUSTED BASED ON THE JUDGEMENT OF THE CONTRACTOR, PROVIDED THE ABOVE-DESCRIBED ROAD DESIGN 200 PRO ERT LINE / N CRITERIA ARE MAINTAINED. OP O I E TURNOUTS,AS SHOWN, SHALL NOT BE REQUIRED R�ID EN IF A 20'M/N.ROAD WIDTH ISPROVIDED INSTEAD. 76b (3,02 OOTPRI P 2 30210 02 SURVEY DATA e (2. 6 ACRE ) / I 125 THIS IS NOT A BOUNDARY SURVEY. THE PROPERTY LINES o� INDICATED IN THIS DRAWING ARE BASED ON AVAILABLE pp \ COUNTY PARCEL DATA DEEMED SUFFICIENT FOR THE = 1 , WORK INTENDED. THE TOPOGRAPHIC DATA PRESENTED IS BASED ON ? O \S AVAILABLE LIDAR DATA COLLECTED FROM THE LOWER \ 12 24 SH PUGET SOUND PROJECT;MASON COUNTY COLLECTION D \ BVF (A ESSO srRc. P/N:2223023000 0 AREA IN 2002, LOCAL TOPOGRAPHICAL DATA MAY NEED TO N D ONSi E SEPT PRIMAR 6.62 RES) BE COLLECTED IF THE SITE APPEARS AL TERED FROM THAT d r— RES RVE DRAI ELD ARE P PE TY LIN DEPICTED IN THESE DRAWINGS. SHEET LIST LL E E PROPO ED DRIVEW4 3 SHEET NO. TITLE \ w/TU O(lTS C1.0 TITLE SHEET&GENERAL LAYOUT V 18 2020 \ CH . N G E S C2.0 ROAD PLAN&PROFILE W SUBMIT CHANGES FOR nPPFaiUAL C3.0 STORMWA TER& TESC PLAN 615 W. Alder Street SITE PLAN 0 100, 200 SCALE: 1"=100' PRIOR TO PERFORNiiiVG �JtUORI" C4.0 DETAILS&NOTES-ROADWAY ❑ C5.0 DETAILS&NOTES-STORM/TESC FILE:X-BASE.dwg Q DRIVEWAYACCESS DESIGN -01 �. F REF, PROJECT.- 20-STEP Q �\o w w„ >� 11510 E STATE ROUTE 106 PERMIT SET UNION,WASHINGTON COVER SHEET& CHECKED BY: KJF 0 E N G I N E E R I N G \N C BRIAN STEFANKO SITE PLAN DETAILED BY.' k, 2724 Black Lake Boulevard SW Suite 202 4775 NE LAMMS LANE o KJF Q 'F �.srrR�O �� rr�uni .N" Tumwater,WA 98512 POULSBO,WA 98370 SHT 1 OF 5 X DESIGNED BY-KJF DATE NO. REVISION BY 11111120 Ph:(360)352-2477 fax:(360)352-0179 E-mail.admin@vectorengineeringinc.com 0 BUF C. - I �I • NO v z 8'x 30'TURNOUT W/ ? ! TAPERS 150'o. P EDc \� �A R I 1 1 1 \ \ c \ \ MODIFIED hTMI 1ERHEAD FIRE \ \ C LtA THESE PLANS PdIC1ST �%r� 1 i \ \ APP RATUS�TLIRNAROUND (/ i E \ ON THE J3B, M N COUNTY \\ PO INSPHGTfON l �, \ 1 \`, \ I ' iJ51 EV1EEl A���CUFtRf�l'T` . \► \ , I } ` UiLD1NG DEPARTMEN WASHINGTON STATE CODES PVI STA:4+76.22 160 PVI ELEV:88.31' 160 _.PAEUEV..22.34' _ - _ -K17.78 140 0.83 140 LV :10.00' _M p--:..... cN7 N 120 o N o `� ~ � 0 o m 4 + 120 O N + N LL1 tf') LLI _. > .. __... _.. V._- V � - my � m � w 9. 0% 100 — _ 100 w AT CL OF EXl . EXISTING m w U m w INSTALL 18"HD CULVERT. LOC TE _ - - E m - ROADSIDE DITC FLOWLINE.-BED IPE PER DETAIL ; GRADE 80 SHEET C-04 ANE PROVIDE 12"MIN COVER OVER PI 80 N � Z 60 -- -- e. - 60 cr U + GRADE 40 _- — — — 40 ----------------- y 20 — L2 0 20 I ci u) c0 [O (O lA Qf tf! (O l[J CO cn O a! cam') allo c N 11 N N N CIS M M �O CV ch f: C ti m � p O II II .3 C.7 v an In to co 1 r I C9 U' T 11 LL 11 II 11 II 11 II 11 11 11 II II II 11 II 11 11 11 II 11 11 II II II II 11 11 II 11 W LL g CD U' CD C7 U U' C7 C7 0 0 CD 0 U' 0 0 0 U' 0 C7 a CD C7 0 W W LL W LL W LL W LL W LL W LL W LL W LL W LL W LL W LL W LL W LL W LL c -0+30 0+00 0+50 1+00 1+50 2+00 2+50 3+00 3+50 4+00 4+50 5+00 5+50 6+00 6+50 7+00 DRIVEWAY PLAN & PROFILE 0 50' 100, SCALE: I"=50' 0 rn o FILE.X84SE.dwg Q L F DRIVEWAYACCESSDESIGN C-02 xPROJECT:20-STEF ® ���a"�s�q� c t o 11510 E STATE ROUTE 106 c © UNION,WASHINGTON mPLAN& CA CHECKEDBY.• KJF ® PERMIT SET E N G I N E E R I N G \N C ROAD PROFILE a 's o 2724 Black Cake Boulevard SW Suite 202 BRIAN STEFANKO o DETAILED BY KJF Q F.IsreaF. �2 4775 NE LAMMS LANE o ssrp Tumwater,WA 98512 x DESIGNED BY.KJF DATE NO. REVISION BY POULSBO,WA 98370 SHT 2 OF .5 11111120 Ph:(360)352-2477 fax:(360)352-0179 E-mail:adminQa vectorengineennginc.com N • J — CJRRFNT FART 111I�<:T G©DF p►k vlEwEp - - �� P, PLIPANCE BMPC101:PRESERVE �' W16HINCGTQN STATE S �J� � c(I)DE 'Om NCp U NTY NATURAL VEGETATION Iy M.P'SO 1m DING DEPARTM 10 c BUF / L GA B m _— I J 1 BMP C105.•STABILIZED BE C-05 CONSTRUCTION ENTRANCE / S NIU ST CL A NG SHA B STA Ll D A 1 HEN SHE JOg SITE \ DlND NNO B ACCD/ RISH� l IMEDAT Y. ON ECTION OF — BUF 'BUF FOR INSP SEE M C12 P& ING O ES, S E C- R M R INFO M ION �BUF BMP C207:CHECK DAMS 3 8 �C INCL. CHANNEL LINING C-04 > � HOUSE 00 n= co C / i 0' �-8- 8 —8 / QOR �E BMP C101:PRESERVE m NATURAL VEGETATION BMP T5.20:RAINWATER HARVETI g o �,► roRAINWATER COLLECTION CISTERNS AR NNED to A > n FOR THE HOUSE,SHED OR BOTH(TBD). rn ROp T 13 HARVESTED RAINWATER SHALL BE LIMITED TO p FRTy NONPOTABLE USES SUCH AS OUTSIDE IRRIGATION, z /N�c TOILET FLUSHING OR COLD WATER LAUNDRY. \ m A BMP C101:PRESERVE LL NATURAL VEGETATION m STORMWATER & TE_S_C PLAN 0 50' 100, SCALE: 1"=50' F � a FILE.X-a4SEdwg © FREF DRIVEWAYACCESS DESIGN o PROJECT. 20-STEF q� L�v"^sv 9� 11510 E STATE ROUTE 106 -03 UN/ON,WASHINGTON m © STORMWATER& CHECKED BY: KJF 2 PERMIT SET E N G I N E E R I N G I N C \ BRIAN STEFANKO TESC PLAN o DETAILED BY KJF Q .2,"0,.i aEo`� 2724 Black Lake Boulevard SW Suite 202 o '•rs�ppAL Eck' Tumwater,WA98512 4775LS O,WA LANE k DESIGNED BY.KJF DATE NO. REVISION BY POULSBO,WA 98370 11111120 ph:(360)352-2477/ax.(360)352-0179 E-mall:adminQvectwengineennginc.com SN7 OF J� TRENCH WIDTH (SEE NOTE 3) THESE PLANS MUST BE CHANGES ON THE JOB SITE GRAVEL BACKFILL FOR D� FOR INSPECTION PIPE ZONE BEDDING tO (L Uti+11'T CHANGES FOR APPROVAL (SEE NOTE 2) ,, RIOP, TO PERFORMING WORK 00 C) Z 0 0 3.00' 6.00' O w a ?� 3:1 --~ 37 FOUNDATION LEVEL ' � a ROAD SECTION TO INCLUDE: m UsT mFET ALL CURRENT THERMOPLASTIC PIPE 2 1/2"MIN.DEPTH ASPHAL T(CLASS A) IIV�t5 H!i t�TO N STAT E CO DES NOTES: 1 1/2"MINUS TOP COURSE(3"THICK) 1. SEE WSDOT STANDARD SPECIFICATION SECTION 7-08.3(3)FOR PIPE ZONE BACKFILL 2 1/2"MINUS BASE COURSE(6"THICK) 2. SEE WSDOT STANDARD SPECIFICATION SECTION 9-03.12(3)FOR GRAVEL BACKFILL FOR PIPE ZONE BEDDING. >� DRI VEWA Y SECTION 3. FOR SANITARY SEWER INSTALLATION, CONCRETE PIPE SHALL BE BEDDED TO SPRING LINE. C-04 SCALE: 1/4"=1'-0" CROSS-CUL VERT BEDDING C-04 SCALE.•N.T.S. REVIEWED PL AONCE CODE COn N IASON COUNTY A 0.25 BUILDING DEPARTMENT w CHECK DAMS NOTES ;o 1. THE MAXIMUM SPACING BETWEEN THE DAMS SHALL BE SUCH THAT THE TOE OF THE UPSTREAM DAM IS AT THE SAME ELEVATION AS THE TOP OF THE KEY INTO CHANNEL DOWNSTREAM DAM. 2. ROCK CHECK DAMS SHALL BE CONSTRUCTED OF 6"MINUS QUARRY SPALLS. Flow THE ROCK MUST BE PLACED BY HAND OR MECHANICAL PLACEMENT TO ACHIEVE TOP OF CHECK DAM TO COMPLETE COVERAGE OF THE DITCH OR SWALEAND TO ENSURE THAT THE BEAT BOTTOM OF PREVIOUS CENTER OF THE DAM IS LOWER THAN THE EDGES. THE ROCK USED MUST BE CHECK DAM ELEVATION LARGE ENOUGH TO STAY IN PLACE GIVEN THE EXPECTED DESIGN FLOW z THROUGH THE CHANNEL. PROVIDE A SUMP IMMEDIATEL Y UPSTREAM OF CHECK DAMS. 3. w MAINTENANCE, CHECK DAMS SHALL BE MONITORED FOR PERFORMANCE AND m SPACING WILL SEDIMENT ACCUMULATION DURING AND AFTER EACH RUNOFF PRODUCING 8 VARY RAINFALL. SEDIMENT SHALL BE REMOVED WHEN IT REACHES ONE HALF THE SECTION n SUMP DEPTH. TRAPPED SEDIMENT SHALL BE REMOVED OR STABILIZED ON SITE. ��� 4. IN ADDITION TO CHECK DAMS, CHANNEL SHALL BE LINED WITH 8"MINUS QUARRY m SPALLS MEETING WSDOT SPEC 9-13.1(5)FOR GRADES GREATER THAN 10%. 3 ROAD WA Y DITCH CHECK DAMS w C-04 SCALE:N.T.S. 0 a FILE.X-BASE.dwg 5 le c t oDRIVEWAYACCESS DESIGN (' PROJECT 20-STEP ``t.F`RE/T/ C_04 x ® ` „�12 11510 E STATE ROUTE f06 UNION,WASHINGTON ' DETAILS&NOTES- PERMIT SET CHECKED BY. KJF E N G I N E E R I N G \N C BRAN STEFANKO ROADWAY k,, 2724 Black Lake Boulevard SW Suite 202 o DETAILED BY: KJF Q �F ,,.,��x<" �` 4775 NE LAMMS LANE si•„ Tumwater, WA98512 DESIGNED BY.KJF DATE NO. REVISION BY �^ h: 360 352-2477 fax. 360 352-0179 E-mail:admin vecloren ineerin inc.com POULSBO, WA 98370 SHT 4 OF J� i� 11111120 P ( ) ( ) @ 9 9 JOINTS IN FILTER FABRIC SHALL BE BMP C120. TEMPORARYAND PERMANENT SEEDING NOTES 2'z2'k 14GA. WIRE FABRIC OR SPLICED AT POSTS. USE STAPLES, 1. SEED MIXTURE AND APPLICATION RATE SHALL BE APPROPRIATE FOR THE AREA 'tt Mr.vTALL URRFNT WIRE RINGS, OR EQUIVALENT TO EQUIVALENT, IF STANDARD AND TYPE OF COVER PROVIDED. s / W,6H!N GT )N S_N E COI3,ES STRENGTH FABRIC USED ATTACH FABRIC TO POSTS. 2 WHEN APPLIED WITH HYDROMUL CH,APPL Y IN TWO PHASES: 2'z2'z14GA. WIRE FABRIC a. PHASE 1-INSTALL ALL SEED AND FERTILIZER WITH 25 TO 30 PERCENT MULCH AND TACKIFIER ONTO SOIL IN THE FIRST LIFT. INSTALL DRIVEWAY / �� OR EQUIVALENT b. PHASE 2-INSTALL THE REST OF THE MULCH AND TACKIFIER IN THE SECOND LIFT. i CULVERT IF ROADSIDE DITCH PRESENT G ROPO�P� 700%Ll/� 3 OBER AND OC� SEED BETWEEN APRIL >AND JUNE 30 OR BETWEEN SEPTEMBER 1 ` 1. 4. SEED BEDS PLANTED BETWEEN JUL Y I AND AUGUST 30 SHALL BE IRRIGATED UNTIL / 75 PERCENT GRASS COVER IS ESTABLISHED. / N 5. SEED BEDS PLANTED BETWEEN OCTOBER 1 AND MARCH 30 SHALL BE MULCHED WITH STRAW OR AN EROSION CONTROL BLANKET UNTIL 75 PERCENT GRASS COVER Z IS ESTABLISHED. AL 6. CONFIRM THE INSTALLATION OFALL REQUIRED SURFACE WATER CONTROL N MEASURES PRIOR TO SEEDING. 7 SEED BEDS SHALL BE FIRM AND ROUGH PRIOR TO SEEDING. WHERE COMPACTION EML E IS REQUIRED FOR ENGINEERING PURPOSES, SLOPES SHALL BE TRACK WALKED 6'MAX BEFORE SEEDING. 4"-8"QUARRY SPALLS GEOTEXTILE POST SPACING MAYBE 8. BACKBLADING OR SMOOTHING IS PROHIBITED ON SEED BEDS STEEPER THAN 4:1. 12"MIN. DEPTH INCREASED 9. IT IS RECOMMENDED THAT AREAS BEING SEEDED FOR FINAL LANDSCAPING (SEE NOTE 1) PROVIDE FULL WIDTH TO 8'/F WIRE BACKING/S USED CONDUCT SOIL TESTS TO DETERMINE THE EXACT TYPE AND QUANTITY OF MINIMUM 4x4 TRENCH OF INGRESS/EGRESS AREA BACKFILL TRENCH WITH 2x4 WOOD POSTS, FERTILIZER NEEDED.MINIMIZE USE OF FERT/L/ZERADJACENT TO WA TER BODIES NATIVE SOIL OR 3/4"- 1 1/2" STEEL FENCE POST, AND WETLANDS. WASHED GRAVEL REBAR OR EQUIVALENT STANDARD EROSION CONTROL NOTES DESICNANO INSrALLAT/ON S7EC/F/C,47/DNS GEOTEXTILE SPECIFICATIONS 1. EROSION CONTROL MEASURES SHALL BE INSTALLED AND APPROVED BY THE POLYMERIC MESH AOS 0.60 mm MAX.FOR SLIT FILM WOVEN(#30 SIEVE) COUNTY PRIOR TO THE BEGINNING OF CONSTRUCTION. 1. STABILIZED CONSTRUCTION ENTRANCE SHALL BE CONSTRUCTED OFA 12"THICK (ASTM D4751) 0.30 mm FOR ALL OTHER GEOTEXTILE TYPES(#50 SIEVE) 2. EROSION CONTROL MEASURES ARE NOT LIMITED TO ITEMS AS SHOWN ON PLANS PAD OF 4"-8"QUARRY SPALLS. 0.15 mm MIN.FOR ALL FABRIC TYPES(#100 SIEVE) OR ON STANDARD DETAILS. THE CONTRACTOR IS RESPONSIBLE FOR THE ALTERNATIVELY:A 4"COURSE OFASPHALT TREATED BASE(ATB), OR THE WATER PERMITTIVITY 0.02 SEC-' INSTALLATION AND MAINTENANCE OF ALL EROSION CONTROL MEASURES. EXISTING PAVEMENT, MAYBE USED. (ASTM D4491) CONTRACTOR SHALL IMPLEMENT MEASURES TO PREVENT MIGRATION OF SILT GRAB TENSILE STRENGTH 180 LB.MIN.FOR EXTRA STRENGTH AND/OR POLLUTED RUNOFF TO OFF-SITE PROPERTIES. 2. THE 100'MIN.LENGTH OF THE ENTRANCE MAYBE REDUCED TO THE MAXIMUM PRACTICABLE SIZE WHEN THE SIZE OR CONFIGURATION OF THE SITE DOES NOT (ASTM D4632) 100 LB.MIN.FOR STANDARD STRENGTH 3. THE CONTRACTOR WILL MAKE REGULAR SURVEILLANCE OFALL EROSION CONTROL ALLOW THE FULL LENGTH(100). GRAB TENSILE STRENGTH 30%MAXIMUM MEASURES. THE CONTRACTOR WILL MAKE ALL NECESSARY REPAIRS, (ASTM D4632) MODIFICATIONS,AND ADDITIONS,AS NECESSARY TO ENSURE THE PROPER ULTRAVIOLET RESISTANCE 70%MINIMUM OPERATION OF THE EROSION CONTROL MEASURES. THE CONTRACTOR SHALL 3. A SEPARATION GEOTEXTILEUMP SHALL BE PLACED UNDER THE SPALLS TO PREVENT FINE SEDIMENT FROM P OM PUMPING UP INTO THE ROCK PAD. THE GEOTEXTILE (ASTM D4355) EMPLOY MORE FREQUENT INSPECTIONS OF EROSION CONTROL MEASURES SHOULD SHALL MEET THE FOLLOWING STANDARDS: ALL GEOTEXTILE PROPERTIES LISTED ABOVE ARE MINIMUM AVERAGE ROLL VALUES SITE OR WEATHER CONDITIONS DICTATE. 4. ALL DISTURBED AREAS SHALL BE SEEDED OR SODDED UPON COMPLETION OF GRAB TENS/LE STRENGTH(ASTM D4751) 200 PS/(MIN.) BMP C233:SIL TFENCE NOTES WORK. DURING THE WET SEASON,NOVEMBER THROUGH MARCH,ALL DISTURBED 1. CONSTRUCT SILT FENCES IN AREAS OF CLEARING, GRADING, OR DRAINAGE PRIOR SOILS WILL BE STABILIZED WITHIN FORTY-EIGHT(48)HOURS AFTER LAND GRAB TENSILE ELONGATION(ASTM D4632) 30%(MAX.) TO STARTING THOSE ACTIVITIES. DISTURBANCEACTIVITIES HAVE CEASED. EROSION CONTROL STABILIZATION 2. ATTACH THE FILTER FABRIC ON THE UP-SLOPE SIDE OF THE POSTS AND SECURE MEASURES WILL INCLUDE,BUTARE NOTLIMITED TO, INSTALLATION OF STRAW MULLEN BURST STRENGTH(ASTM D3786-80a) 400 PSI(MIN) WITH STAPLES, WIRE, OR IN ACCORDANCE WITH THE MANUFACTURER'S MATTING,JUTE MATTING, STRAW MULCHAND/OR WOOD CHIPS,AND COVERING THE E AOS(ASTM D4751) 20-45(U.S. STANDARD SIEVE SIZE) RECOMMENDATIONS.ATTACH THE FlL TER FABRIC TO THE POSTS IN A MANNER AFFECTED AREA AND SPOIL PILES WITH PLASTIC SHEETING. THE CONTRACTOR THAT REDUCES THE POTENTIAL FOR TEARING. WILL BE RESPONSIBLE TO ENSURE THAT COMPLETE COVERAGE OF THE DISTURBED 4. FENCING(SEE BMPS C 103)SHALL BE INSTALLED AS NECESSARY TO RESTRICT 3. BURY THE BOTTOM OF THE FILTER FABRIC 4-INCHES MIN.BELOW THE GROUND AREAS IS PROVIDED AND THAT GROWTH OF VEGETATION IS ESTABLISHED. SEED TRAFFIC TO THE CONSTRUCTION ENTRANCE. SURFACE.BACKFILL AND TAMP SOIL IN PLACE OVER THE BURIED PORTION OF THE AND SOD APPLICATIONS WILL BE CONDUCTED IN ACCORDANCE WITH THE 0 FIL TER FABRIC, SO THAT NO FLOW CAN PASS BENEATH THE FENCE AND SCOURING TIMELINES NOTED MI THE MOST RECENT EDITION OF THE STANDARD ? CANNOT OCCUR. WHEN WIRE OR POL YMERIC BACK-UP SUPPORT MESH IS USED, SPECIFICATIONS. 5. WHENEVER POSSIBLE, THE ENTRANCE SHALL BE CONSTRUCTED ON FIRM, THE WIRE OR POLYMERIC MESH SHALL EXTEND INTO THE GROUND 3-INCHES MIN. COMPACTED SUBGRADE. THIS CAN SUBSTANTIALLY INCREASE THE 5. THE CONTRACTOR WILL CHECKALL SEEDED OR SODDED AREAS REGULARLY TO m . 4. USE WOOD, STEEL OR EQUIVALENT POSTS. THE SPACING OF THE SUPPORT POSTS EFFECTIVENESS OF THE PAD AND REDUCE THE NEED FOR MAINTENANCE ENSURE THAT THE VEGETATIVE COVER IS BEING ADEQUATEL Y ESTABLISHED.AREAS SHALL BEA MAXIMUM OF 6-FEET.POSTS SHALL CONSIST OF EITHER: N WILL BE REPAIRED,RESEEDED,AND FERTILIZED AS REQUIRED. 6. CONSTRUCT AND MAINTAIN THE CONSTRUCTION ENTRANCE IN ACCORDANCE 4.1. WOOD WITH DIMENSIONS OF 2-INCHES BY2-INCHES WIDE MIN.AND A 3-FEET 6. TRACKING OF SOIL OFF-SITE WILL NOT BEALLOWED. IFANY SOIL lS TRACKED WITH THE DEPARTMENT OF ECOLOGY STANDARDS(STORMWATER MANAGEMENT MIN. LENGTH. WOOD POSTS SHALL BE FREE OF DEFECTS SUCH AS KNOTS, BEYOND THE LIMITS OF THE SITE, IT WILL BE REMOVED BEFORE THE END OF THAT m MANUAL, LATEST EDITION). SPLITS, OR GOUGES. WORKING DAY. TO PREVENTADDITIONAL TRACKING, VEHICLE TIRES MUST BE REVIEWED FOR 4.2. N0. 6 STEEL REBAR OR LARGER. SWEPT OR WASHED PRIOR TO LEAVING THE PROJECT SITE. 3° CODE COMPLIANCE 4.3. ASTM A >20 STEEL PIPE WITH A MINIMUM DIAMETER OF 1-INCH. 7. NO MORE THAN 500 LINEAR FEET(LF)OF TRENCH ON DOWN-SLOPE OF MORE g 4.4. U, T,L, OR C SHAPE STEEL POSTS WITH A MINIMUM WEIGHT OF 1.35 LBS./FT. F'E S E FLANS MUST B E MASON COUNTY 4.5. OTHER STEEL POSTS HAVING EQUIVALENT STRENGTH AND BENDING THAN FIVE(5)PERCENT WILL BE OPENED AT ONE TIME. O N i H E JOB SITE 8. EXCAVATED MATERIAL WILL BE PLACED ON THE UPHILL SIDE OF TRENCHES. F O� INSPECTION �U i L D;N G DEPARTMENT RESISTANCE TO THE POST SIZES LISTED ABOVE. 9. EXCAVATED MATERIAL WILL NOT BE PLACED IN ESTABLISHED DRAINAGE DITCHES, UNDER ANY CIRCUMSTANCES. 1 STABILIZED CONSTRUCTION ENTRANCE 2� SIL T FENCE 10. CONTRACTOR SHALL ESTABLISH SEDIMENT TRAP FOR ALL TRENCH DEWATERING o C-05 SCALE.N.T.S. C-OS SCALE.N.T.S. " OPERATIONS. a FILE:X-BASE.dwg Q DRIVEWAYACCESSDESIGN'ae�� C-05 o PROJECT: 20-STEP 11510 E STATE ROUTE 106 Q - -•-- UNION,WASHINGTON a CHECKED BY, KJF TAILS&NOTES- PERMI T SET E N G I N E E R I N G \N C DE STORM I TESC 0 BR/AN STEFANKO o DETAILED BY KJF 1 .F.R,,,�,`��.R�.o \� 2724 Black Lake Boulevard SW Suite 202 Tumwater, WA 98512 4775 NE LAMMS LANE x DESIGNED BY.KJF DATE NO. REVISION BY 11 11120 Ph:(360)352-2477 fax.(360)352-0179 E-mail.admin@vectorengineeringinc.com POULSBO,WA 98370 SHT 5 OF 5