Loading...
HomeMy WebLinkAboutWPO200500026 Plan - Stormwater 2005-06-21E&SC LEGEND E&SC STD, 6 SPEC CE TEMP. STONE CONST. ENTRANCE 3.02 SF SILT FENCE 3.05 CIP CULVERT INLET PROTECTION 3.08 DID TEMPORARY DIVERSION DIKE 3.09 ST TEMPORARY SEDIMENT TRAP 3.13 TSD TEMPORARY SLOPE DRAIN 3.15 OP OUTLET PROTECTION 3.16 CD ROCK CHECK DAMS 3.20 LS LEVEL SPREADER 3.21 TO TOPSOILING 3.30 TS TEMPORARY SEEDING 3 31 The developer shall reserve the right to Install, maintain, remove and/or convert to Permanent stormwater management facilities (where applicable) all erosion control measures required by this plan regardless of the sale of any lot. N / / O / / - Silt Trap #2 VICINITY MAP Kevlewed a Drainage Area (ac): 0.33 . Wet Storage Req (cy): 22.11 Dry Storage Req (cy) : 22.11 708 Date: 221 Total Storage Req (cy),. 44.22 File#: wfl T 'i o Elev Side 1 Side 2 Area Vol Vol _ I C \ (sf) (cf) (cy) 9 v Low Point 734.0 8 B 64.0 \ I I 1: 1 side slope Bottom of Weir: 738.0 16 16 256.0 640.0 23.7 wet 3: 1 side slope 710 1� ti ti Top of Weir 739.6 22.4 21.4 501.8 606.2 22.5 dry \ �P 0 Weir Length (ft) : . 708 29 Ln � Weir Height (ft) : 1.6 o Top of Berm: 740.6 696 0 Top of Weir: 739.6 Berm Width (ft) : 2.5 r \ N Q QQ 5Q I SITE Silt Trap #1 \ \\ Drainage Area (ac): 0.32 PS PERMANENT SEEDING 3.32 Wet Storage Req (cy): 21.44 SO 50DDING 3.33 / / / / %� \ \ Dry Storage Req (cy): 21.44 RED O MU MULCHING 3.35 I / • \ �� �- o Total Storage Req (cy): 42.88 29 HILL �P B/M SOIL STABILIZATION BLANKETS/MATTING 3.36 I / / / / / ti ',d 1 �� i J Elev Side 1 Side 2 Area Vol Vol q DC DUST CONTROL 3.39 I / / oo71 Va K,4' / �" v of / TOCKIL'ILE / ^ / / / / / yQ) u) _ ) /0 LIMITS OF / \ DISTURI?�ANCE I 1 I 1 I 1 5 y - / - - - - _ v 1 O I d �A�' P)MP PLANTING SCHEDULE \ 8 ///`���''''''��� ( . .�(6) 1.5• cal Red Maple • f121 8' mix Borborry/Spico Bush Ibio-filter) CIO -FILTER BE�jN1y / �I� \ \ / / / / / \ 4 OR 6' PERFORATED PVC 2I EC-2 \ \ �� / / / / PIPEo POSITVE SLOPE \ \ \ \ \ \� • \ 2�j�/, / WITH CLEANOUTS EVERY 50' 00 \\ \\ I� \ \ \ 1 \ \\ ,10 \ \ \ \\ \o T I 1 kSIO-r IL 1 Lk 4 OR 6"NON- PERFORATED PVC PIPE 0 POSITVE SLOPE \ \ \ Oy I 4 01 \ (sf) (cf) (cY) QP�\. I \\ S T 1 Low Point 734.0 8 7 56.0 760 1: 1 side slope 712 f� Bottom of Weir: 738.0 16 15 240.0 592.0 21.9 wet -: - r 3: 1 side slope \ \ Top of Weir 739.7 22.8 21.8 497.0 626.5 23.2 dry SCALE -. 1" = 4000' \ Weir X Length (ft) : 1 . 9 ° \ Weir Height (ft): 1.7 Top of Berm: 740.7 N F�'A Top of We 739.7 GENERAL EROSION AND SEDIMENT CONTROL NOTES QF.QP\`Q I r Berm Width (ft) : 2. 5 / �Pg �Q \ ES-1: UNLESS OTHERWISE INDICATED, ALL VEGETATIVE AND STRUCTURAL EROSION AND cn v SEDIMENT CONTROL PRACTICES WILL BE CONSTRUCTED AND MAINTAINED ACCORDING O LAG ti TO MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA EROSION AND / lip p� J SEDIMENT CONTROL HANDBOOK AND VIRGINIA REGULATIONS VR 625-02-00 EROSION AND SEDIMENT CONTROL REGULATIONS. ES-2: THE PLAN APPROVING AUTHORITY MUST BE NOTIFIED ONE WEEK PRIOR TO THE PRE - CONSTRUCTION CONFERENCE, ONE WEEK PRIOR TO THE COMMENCEMENT OF LAND n DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPECTION. r ES-3: ALL EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE PLACED PRIOR TO OR AS 44 e +b+iftTNIW THE FIRST STEP IN CLEARING. / Reviewed and Approved by the ES-4: A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL PLAN SHALL BE / II MAINTAINED ON THE SITE AT ALL TIMES. Community Development Department ES-5: PRIOR TO COMMENCING LAND DISTURBING ACTIVITIES IN AREAS OTHER THAN Date: Z ( JUtjF- zoo - INDICATED ON THESE PLANS (INCLUDING, BUT NOT LIMITED TO, OFF -SITE BORROW OR File#• Z eo • oos'- c9 WASTE AREAS) , THE CONTRACTOR SHALL SUBMIT A SUPPLEMENTARY EROSION CONTROL I I I \ PLAN TO THE OWNER FOR REVIEW AND APPROVAL BY THE PLAN APPROVING AUTHORITY. I / I ES-B: THE CONTRACTOR IS RESPONSIBLE FOR INSTALLATION OF ANY ADDITIONAL EROSION I I I \ gnatu"e CONTROL MEASURES NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS DETERMINED BY THE PLAN APPROVING AUTHORITY. I / \ ES-7: ALL DISTURBED AREAS ARE TO DRAIN TO APPROVED SEDIMENT CONTROL MEASURES AT 1 r ALL TIMES DURING LAND DISTURBING ACTIVITIES AND DURING SITE DEVELPMENT UNTIL FINAL STABILIZATION I5 ACHIEVED. ES-8: DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED I \� FILTERING DEVICE. I \ 1 I I I \ ES-9: THE CONTRACTOR SHALL INSPECT ALL EROSION CONTROL MEASURES PERIODICALLY AND 1 I I I I I \ I\\ AFTER EACH RUNOFF -PRODUCING RAINFALL EVENT. ANY NECESSARY REPAIRS OR I II J \ CLEANUP IMMEDIATELY. SouthTHE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL BE MADE 1 I South Fcrk Farms I Erosion/Sediment Control Narrative I March 2i, 2005 I 1 PROJECT DESCRIPTION The project consists of construction of a road for a rural, large lot, subdivision. The total I I I I I I drainage area of 3.5 acres. EXISTING SITE CONDITIONS The site is mostly pasture. ADJACENT PROPERTY TEMPORARY PERMANENT Sediment Trap To Stormwater BMP Construction Notes 1. All disturbed areas must be stabilized with pavement or a good stand of vegetation prior to the conversion of the trap to a stormwater BMP. 2. Accumulated sediment must be removed from the trap to a depth 24" below the stone weir (see detail), the interior slopes of the trap regraded to 3:1 or flatter, and the stone weir repaired if necessary. 3. De -watering Trench shall be installed in accordance with the attached Sediment Trap to BMP Plan and the De - watering Trench Detail . 4. After installation of the de -watering trench, the bottom of the stormwater BMP will be covered with at least 2' of a 50/50 mixture of sand and topsoil, and then permanent seed 6 mulch applied. CLEAN -OUT W/WATERTIGHT CAP 670.0' ------------- ------------- ------------- --- ------- -------- --- - -- - i inin Cnnn e Tni r•n n vri TOPSOIL 6 SAND SAND: 0.02-0.04" (ASTM C-33 FINE) O,(MUST BE INSPECTED BY WATER RESOURCES MANAGER N EROSION CONTROL INSPECTOR) (see note #2 below) The road enters the project from state route 708 to the east. The rest of the property is surround,;d by rural parcels: 87-16D, 87-16C, 87-16A1, 87-18&,87-22J and 87-16F. OFFSITE AREAS No off -site areas will be disturbed. SOILS Braddock. Loam on 7-15% slopes is a deep, strongly sloping, well drained to excessively drained ;,oil Pound on ridgetops, points of ridges, and on side slopes. The surface layer is brown sandy loam about 5 Inches thick. The substratum is mostly brown and yellow partially weathered bedrock that crushes to sandy loam to a depth of about 60 Inches. Permeability is rapid. and available water capacity is low. Surface runoff Is rapid. The hazard of erosion is moderate. CRITICAL EROSION AREAS. There are no critical erosion areas.. EROSION AND SEDIMENT CONTROL MEASURES Unless ortierwise Indicated, oil veoetative and st-ucturol ero�ion and sediment control practice! will be constructed and maintained according to minimum standards and specifications of tho Virginia Erosion and Sediment Control Handbook (VESCH). STRUCTURAL PRACTICES 1. Construction Entrance- 3.02 A temporary Construction entrance will be provided upon field determination by the County and the contractor. A temporary paved construction entrance shall be Installed at the beginning Of the project. 2. Silt Fence- 3.05 A tbmpoi-ary sediment barrier consisting of a synthetic filter fabric stretched across and attached to supporting posts and entrenched. 3. TomP orary Sediment Trap - 3.13 A small ponding area, formed by construction an earthen embankment with a stone outlet across a drainage swolb. VEGETATIVE PRACTICES 1. Temporary Seeding - 3.31 Establishment of temporary vegetative cover on disturbed areas by seeding with appro riate rapidly growing plants on sites that will not be brought to final grade for brides of 3 days to one year. Garman Millet at 60 Ib./oc.. Weeping Lovegrass at 3 Pb./ac.. Korean Lespedozo at 20 lb./ac. Temporary seeding shall be fertilized. Fertilizer shall be applied at a rate of 600 Ibs/acre of 10-20-10 according to the handbook. The builder may save considerable funds by having ire soil tested by VA TECH (kits are available at the extension office and the test costs $6.00). 2. Mulch - 3.35 Organic mulch shall be used In conjunction with seeding operations and shall be applied at the rate of 2 tons/acrb. 3. Dust Control- 3.33 Dust control Measures shall be utilized throughout this site when necessary. Typlcal temporary measures include but are not limited to, Irrigation, temporary seeding barriers. These measures will aid in the prevention of harmful airborne substances as well the effects of wind erosion MANAGEMENT STRATEGIES 1. Construction should be sequenced so that grading operations can begin and end as quickly as possible. 2. Sediment trapping measures shall be installed as a first stop in grading and shall be seeded and mulched immediately following Installation. 3. The job superintendent shall be responsible for the installation and maintenance of all erosion and sediment control practices. 4. Temporary seeding or other stabilization will follow immediately after grading. 5. Areas which are not to be disturbed will be clearly marked by flags, signs, etc. PERMANENT STABILIZATION All areas disturbed by construction will be stabilized with permanent seeding Immediately following finish grading. Seeding will be done with Kentucky 31 Tall Fescue according to Std. 8 Spec. 3.32 of The Virginia Erosion 9 Sediment Control Handbook. 5-20-10 fertilizer shall be applied at the rate of 1000 lb/ac and lime at 2 tons/ac. Permanently seeded areas shall be protected during establishment with straw mulch (2 tons/acl. STORMOATER MANAGEMENT This is a rural subdivision with negligible change in stormwater peak flows. The large downstream silt trap will be converted to a bio-filter to address water quality as shown on the Preliminary plat. MAINTENANCE In gbnercll, all erosion and sediment control measures will be checked weekly and after each significant rainfall. The following items will be checked in particular: 1) The sediment traps and basins will be cleaned and maintained according to the VESCH. 2) All gravel outlets will be chocked regularly for sediment buildup which will prevent drainage. If the gravel is clogged by sediment, it shall be removed and cleaned or replaced. 3) Silt Pence will be checked regularl for underminin or deterioration of the fob d \ r \700. I SILT TRAP / BIO-FILTER -6 'I UnHII-� PVC PIPE AT 1% � � �` BIOFILTER CROSS SECTION (AASHTO M43, 1/2"-1 ") y g ria an repaired as required. Sediment shall be removed when the level of sediment deposition (converted after stabilization) SLOPE (MIN) WRAPPED IN FILTER FABRIC STORMWATER/BMP NOTES reaches half way to the top of the barrier. I \ During construction basin will act oat as silt trap. 1. BMP is not to be constructed until the site is adequately stabilized, according to Water Resources Personnel (434-296-5861) . All sbbdod areas will be checked regularly to see that a good stand Is maintained. Areas should be fertilized and reseeded as needed. After site ,s stabilized, basin will be converted to bio-filter. Silt be 2. The bio-filter soil mix must be the Luck Bio-filter Mix available from Luck Stone or a tested and approved equivalent. MS-1 Stabilization of Denuded Areas and Soil Stockpiles a to cleaned out. underdrom I I \ 1 installed, soil mix added and cover installed. 3. For The addional information contact Water Resoruces Personnel (434-296-5861). sand/soil mix must be stabilized with sod along with the trees and/or shrubs listed on the Permanent or temporary soil stabilization must be applied to denuded areas within seven days \ I Bio-Filter Sizing g plan. after final grade Is reached on any portion of the site. Temporary soil stabilization shall 9 24975 sf ultimate mporvious02.5x=625 sf roc{ be applied within seven days to denuded areas that may not be at final grade, but will vided I I I I I Bio-Filter Hooting �E�N 1336 sf o 400/ac = 1e loots I I I I 21 8'cmlix ix IBarrborry/Se/Pir, Oak co Bush - - - - - 44 \ _ � \ � WATER - - - _ \ / I I r P `2 AC d DIVERSION I I \ _Silt trap during construction. Silt Trap #3 I / Drainage Area (ac) : 2.83 / / \ After site is stabilized.wrap-wil+-bo-_convortod\to I ) I I I \ Wet Storage Req (cy) : 1B9.61 _ o bio-filter. Silt to bo cleanod out, uppdordroin I Dr Storage Re instofed"od mix added and cover irlstallod. / / / I \ \ Y g q (Cy) : 179. 61 Total Storage Req (cy) : 379. 22 Elev Side 1 Side 2 Area Vol Vol (sf) (cf) (cy) Low Point 666.0 36 36 1296.0 1: 1 side slope - Bottom of Weir: 670.0 44 44 1936.0 6464.0 239.4 wet Top ofdWeirope 672.6 54.4 54.4 2959.4 6364.0 235.7 dr Weir Length (ft) : 21.0 o���PLTH OF t/I9c W. THOMAS MUNCASTER, JR. C) CERT. NO. 16242 q +/z7/os Top of Berm: 673.E GRAPHIC SCALE 1 "=60 ' Top of Weir: 672.6 Berm Width (ft) : 3.0 0 60 120 180 remain dormant (undisturbed) for longer than 30 days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year. Soil stabilization refers to measure which protect soil from the erosive forces of raindrop Impact and Plowing water. Applicable practices include vegetative establishment, mulching, and the early application of gravel base on areas to be paved. Soil stabilization measures should be selected to be appropriate for the time Of year, site conditions and estimated duration of use. MS-4 Timing and stabilization of Sediment Trapping Measures Sediment basins and traps, perimeter dikes, sediment barriers and other measures intended to trap sed mont shall be constructed as a first step in any land -disturbing activity and shall be made functional before up -slope land disturbance takes place. MS- 5 Stabilization Measures Stabilization measures shall be applied to earthen structurbs such as dams, dikes and diversions immediately after installation. MS- 17 Vehicle Access Where construction vehicle access routes Intersect paved public roads, provisions shall be made to minimize the transport of sediment by (vehicular) tracking onto the paved surface. Where sediment is transported onto a public road surface, the road shall be cleaned thoroughly at the end of each day. Sediment shall be removed from the roads by shoveling or sweeping and transported to a sediment control disposal area. Street washing shall be allowed only after sediment is removed in this manner. This provision shall apply to individual subdivision lots as well as to larger land disturbing activities. MS-18 Disposition of Temporary Measures All temporary erosion and sediment control measures shall be removed within 30 days after final site stabilization or after the temporary measures are no longer needed, unless otherwise authorized by the local program administrator. Trapped sediment and the disturbed soil areas resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sedimentation. lid by the Department o" m m 1.. m Q u, a 0 m cn z 0 LU 0 z m O W a (U O v F-- m in y co C Z v E O E o �y in U m J' Ir 0 z Q LIJ 0- Q LD I -I z ZZ-1 M W E CD -J C LL Q > 3 LL Q �[ } O z ~ U) O :::) P LL O Cd LL) J --1 O Q Q O :�E : Z W m O U X Q Q z O O Ir LIJ DESIGNED BY DATE TM 3/17/05 DRAWN BY DATE TM CHECKED BY DATE FILE EDIT South Fork Farms - SCALE 1 " =60 DRAWING 1: 1 PLOT PROJECT - OF 1 SHEET NO.