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HomeMy WebLinkAboutWPO201300033 Plan - Stormwater Stormwater Management Plan 2006-02-17n ` i it{ -'i: s ,y1.; l'51 ' c?,UU'fi ;Ai -.ale `M1 s Po tino - V }u j LI\`1I-SCIA I L)IINK I UK L) I- I F IL WALL NAG'K5 TYPICAL) ONC.:.: WALX. I i / \ 0 i 11 i _J L) it EXISTING Ln 0 1 I I I BUILDING PE IPE O I Z I Q4 co I y 19 I I I LTJ "`^• ,,,/ i J i I Lu FF -4 6.6 ti J v Q I 16 i I CO i [ a cf X17 PLAYFIELD cv W 4 o a 1 11 I i i > / i i ICl- STOCKPILE d I i r I - i I _ o_ G r T C PILEI I I I \ S AREA / I o N 161 LIMITS OF CLEARING X7 I 1 1' I iII I I I I i! /cEo. i M 1 LLJ t XI II - i E I . z Li L h I I ' \ \ / Roof drains to BMP (1( / ON J \ During construction basin will act as silt trap. It shall be graded to subgrade. I After seta is stabilized, trap will be converted to FF ELEV= 449.0 a bio -filter. Silt to be cleaned out, underdram I I installed, sod mix added and cover installed. EXl \ 1 J i I WALK PROPOSED MULTI-PURPOSE 3.2 2 -HP FIRE 13. 5'i n WALL I \ II 0' PUBLIC RO 100'x65' \ PHASE 2 I Q, FF -449.0' r I I I I EXISTING I / ASPHALT 810 -FILA F_Rp- Q PLAY ARECJIIa 4 OR 6' FjERFORATED PVC v P z 7PIPEc POSITIVE SLOPE WITH GLEANOUTS EVERY i\ d o 810-FiLTER 4 OR 6'NON- PERFORAT D Pvc E E Y PIPE® POSiTVE SLOPE _ ROPOSED NEW CLASSF OOMS ( 18 ' 444+6 \ 450+s EXIST ' G RAVEL i seleto\ - - Con. Sidewalk , I 3 44\ \ Y : V \ - Proposed O 5 IW X--- _ - - -- --- -- SAFETYr7 NCE i I I l FOR TRE.E. ROTEGTION \ - \ \ \ _ -FOR TREEEPROTEGTION 6O' U( SLUR EBD \BUFFEIR it NOTE: ANY TREES WITHIN THE (1.0' UNDISTURBED BUFFER i LIMITS OF CLEARING I THAT DIE WITHIN ONE YEAR OF THE RELEACE OF THE WPO POND a Dainagge Area (qc) : 0.36 \MUST 8E REPLACED WITH THE SAME SPECIES -THAT DlED46' MIN HEIGHT). I 1 W;t Storage Req(cy): 24.12 \ \ - €-XISHNU_STORM Z Dray Stor age Req cy) : 24.12 _ DRAINAGE \ i I \ JLu Total Stvage Req\ (Cy) : 48.24 \ \ i _ \ STRUCTURES \ I \ o Ele\v Side 1 Side 2 Area, Vol VO., \ \ 1 I I \ \ ( sf) - (cf) (c)) LOW Point 439.0 34 13.25 450.5 ( \ I y \ 1:1 Me slope Bottom of Weer: 442.0 X40 19.25 770.0 1630.8 67.8 wet I i 2.5:1 side slope Top of Weir 443.2 46.0 24.65 1133.9 1142.3 42.3 dry i Weir Lenggth (ft) : 2.2 - i .._._ - \ \ k o°'`° i Weir HeiNt (ft) : 1 0 I \ Top of Berm: 444.0 \ /// I U) \ ` Top of Weir' 443.0101 X \ Berm Width ft) 3.0 \ Ile R TEMPORARY PERMANENT ki N° - SOUTHERN PARKWAY(PT 11 5) (9 AR Sediment Trap To Stormwater BMP Construction No es6iI5t' l8". 40• I i \ 1. All disturbed areas must be stabilized wit pavement or 4SH Op a good stand of vegetation prior to the con Ver ion of the I I \ A minimum water top of 1 inch must be installed with a minimum 1 inch ballcock shutoff valve supplying a y G j trap to a stormwater BMP. O wash hose with a diameter of 1.5 inches for adequate constant pressure. Wash water must be, carried away from the entrance to an approved settling area to remove sediment. All sediment shall be prevented from 2. Accumulated sediment must be removed fr m the trap to a entering storm drains, altches or water courses. ) depth .18 below the stone weir (see detail), the interior v slopes of the trap regraded to 3:1 or fla ter, and the stone Bio -Filter Sizing: 6844 +6500= 13344 sf impervious@5% 667 sf required ce 770 sf provided Bio -Filter Planting 770 sf @ 400/ac = 7 plants Volume: 13344 sf @ 1" =1112 cf required Temporary Construction Entrance ) The entrance and disturbance is temporary and not a permanent entrance to the area. Waiver approved by the Planning Commission on P g August 23, 2005 i i of 67 weir r e p a i r e d if necessary. 3. De -watering Trench shall be insta ed in accordance with the attached Sediment Trap to BMP P an and the De - watering Trench Detail . Prior t installation, the location and orientation of the Tench shat 1 be field determined by David Hirschma Water Resources Manager) and the Contractor. Z ENSC STD, G a ion th d - t CE TEMP. STONE CONST. ENTRANCE 3.02 SF i Oy 3.05 CIP CULVERT INLET PROTECTION Conveyance DD TEMPORARY DIVERSION DIKE Channel L } N6 ? L TSD L0 3.15 OP X 3.18 CD ROCK CHECK DAMS 3.20' LS LEVEL SPREADER PLAN TO TOPSOILING TS TEMPORARY SEEDING G prop Hump i Important) PS PERMANENT SEEDING G0" Vegetation SODDING 3.33 MU MULCHING Original Grade Trench cut out for SOIL STABILIZATION BLANKETS/MATTING 3.36 Installation of riprop DUST CONTROL 3.39 PROFILE LI\`1I-SCIA I L)IINK I UK L) I- I F IL WALL NAG'K5 TYPICAL) ONC.:.: WALX. I i / \ 0 i 11 i _J L) it EXISTING Ln 0 1 I I I BUILDING PE IPE O I Z I Q4 co I y 19 I I I LTJ "`^• ,,,/ i J i I Lu FF -4 6.6 ti J v Q I 16 i I CO i [ a cf X17 PLAYFIELD cv W 4 o a 1 11 I i i > / i i ICl- STOCKPILE d I i r I - i I _ o_ G r T C PILEI I I I \ S AREA / I o N 161 LIMITS OF CLEARING X7 I 1 1' I iII I I I I i! /cEo. i M 1 LLJ t XI II - i E I . z Li L h I I ' \ \ / Roof drains to BMP (1( / ON J \ During construction basin will act as silt trap. It shall be graded to subgrade. I After seta is stabilized, trap will be converted to FF ELEV= 449.0 a bio -filter. Silt to be cleaned out, underdram I I installed, sod mix added and cover installed. EXl \ 1 J i I WALK PROPOSED MULTI-PURPOSE 3.2 2 -HP FIRE 13. 5'i n WALL I \ II 0' PUBLIC RO 100'x65' \ PHASE 2 I Q, FF -449.0' r I I I I EXISTING I / ASPHALT 810 -FILA F_Rp- Q PLAY ARECJIIa 4 OR 6' FjERFORATED PVC v P z 7PIPEc POSITIVE SLOPE WITH GLEANOUTS EVERY i\ d o 810-FiLTER 4 OR 6'NON- PERFORAT D Pvc E E Y PIPE® POSiTVE SLOPE _ ROPOSED NEW CLASSF OOMS ( 18 ' 444+6 \ 450+s EXIST ' G RAVEL i seleto\ - - Con. Sidewalk , I 3 44\ \ Y : V \ - Proposed O 5 IW X--- _ - - -- --- -- SAFETYr7 NCE i I I l FOR TRE.E. ROTEGTION \ - \ \ \ _ -FOR TREEEPROTEGTION 6O' U( SLUR EBD \BUFFEIR it NOTE: ANY TREES WITHIN THE (1.0' UNDISTURBED BUFFER i LIMITS OF CLEARING I THAT DIE WITHIN ONE YEAR OF THE RELEACE OF THE WPO POND a Dainagge Area (qc) : 0.36 \MUST 8E REPLACED WITH THE SAME SPECIES -THAT DlED46' MIN HEIGHT). I 1 W;t Storage Req(cy): 24.12 \ \ - €-XISHNU_STORM Z Dray Stor age Req cy) : 24.12 _ DRAINAGE \ i I \ JLu Total Stvage Req\ (Cy) : 48.24 \ \ i _ \ STRUCTURES \ I \ o Ele\v Side 1 Side 2 Area, Vol VO., \ \ 1 I I \ \ ( sf) - (cf) (c)) LOW Point 439.0 34 13.25 450.5 ( \ I y \ 1:1 Me slope Bottom of Weer: 442.0 X40 19.25 770.0 1630.8 67.8 wet I i 2.5:1 side slope Top of Weir 443.2 46.0 24.65 1133.9 1142.3 42.3 dry i Weir Lenggth (ft) : 2.2 - i .._._ - \ \ k o°'`° i Weir HeiNt (ft) : 1 0 I \ Top of Berm: 444.0 \ /// I U) \ ` Top of Weir' 443.0101 X \ Berm Width ft) 3.0 \ Ile R TEMPORARY PERMANENT ki N° - SOUTHERN PARKWAY(PT 11 5) (9 AR Sediment Trap To Stormwater BMP Construction No es6iI5t' l8". 40• I i \ 1. All disturbed areas must be stabilized wit pavement or 4SH Op a good stand of vegetation prior to the con Ver ion of the I I \ A minimum water top of 1 inch must be installed with a minimum 1 inch ballcock shutoff valve supplying a y G j trap to a stormwater BMP. O wash hose with a diameter of 1.5 inches for adequate constant pressure. Wash water must be, carried away from the entrance to an approved settling area to remove sediment. All sediment shall be prevented from 2. Accumulated sediment must be removed fr m the trap to a entering storm drains, altches or water courses. ) depth .18 below the stone weir (see detail), the interior v slopes of the trap regraded to 3:1 or fla ter, and the stone Bio -Filter Sizing: 6844 +6500= 13344 sf impervious@5% 667 sf required ce 770 sf provided Bio -Filter Planting 770 sf @ 400/ac = 7 plants Volume: 13344 sf @ 1" =1112 cf required Temporary Construction Entrance ) The entrance and disturbance is temporary and not a permanent entrance to the area. Waiver approved by the Planning Commission on P g August 23, 2005 i i of i W. THOMAS MUNCASTER JR. i n CERT. NO. 16242 A 2 aFQ4, OFESS0 weir r e p a i r e d if necessary. 3. De -watering Trench shall be insta ed in accordance with the attached Sediment Trap to BMP P an and the De - watering Trench Detail . Prior t installation, the location and orientation of the Tench shat 1 be field determined by David Hirschma Water Resources Manager) and the Contractor. Z ENSC STD, G a ion th d - teeno ering trench, the bottom 1133.9 cf @ 443.2 provided9 1 SOUTHERN PARKWAY (RT 1165) EP 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 BENCHMARK: FF EX BUILDING (456.6') mulch applied. CHARLOTTESVILLE I - 64 / O SITE Q y V2 VICINITY MAP / 1' = 2000'1. GENERAL EROSION AND SEDIMENT CONTROL NOTES ES -1: UNLESS OTHERWISE INDICATED, ALL VEGETATIVE AND STRUCTURAL EROSION AND SEDIMENT CONTROL PRACTICES WILL BE CONSTRUCTED AND MAINTAINED ACCORDING TO MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK AND VIRGINIA REGULATIONS VR 625-02-00 EROSION AND SEDIMENT CONTROL REGULATIONS. ES-,?: THE PLAN APPROVING AUTHORITY MUST BE NOTIFIED ONE WEEK PRIOR TO THE PRE - CONSTRUCTION CONFERENCE, ONE WEEK PRIOR TO THE COMMENCEMENT OF LAND DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPECTION. ES -:3: ALL EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE PLACED PRIOR TO OR AS THE FIRST STEP IN CLEARING. ES -4: A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL PLAN SHALL BE MAINTAINED ON THE SITE AT ALL TIMES. ES -5: PRIOR TO COMMENCING LAND DISTURBING ACTIVITIES IN AREAS OTHER THAN INDICATED ON THESE PLANS (INCLUDING, BUT NOT LIMITED TO, OFF-SITE BORROW OR WASTE AREAS), THE CONTRACTOR SHALL SUBMIT A SUPPLEMENTARY EROSION CONTROL PLAN TO THE OWNER FOR REVIEW AND APPROVAL BY THE PLAN APPROVING AUTHORITY. ES -6: THE CONTRACTOR IS RESPONSIBLE FOR INSTALLATION OF ANY ADDITIONAL EROSION CONTROL MEASURES NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS DETERMINED BY THE PLAN APPROVING AUTHORITY. ES -7: ALL DISTURBED AREAS ARE TO DRAIN TO APPROVED SEDIMENT CONTROL MEASURES AT ALL TIMES DURING LAND DISTURBING ACTIVITIES AND DURING SITE DEVELPMENT UNTIL FINAL STABILIZATION IS ACHIEVED. ES -H: DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED FILTERING DEVICE. ES -9: THE CONTRACTOR SHALL INSPECT ALL EROSION CONTROL MEASURES PERIODICALLY AND AFTER EACH RUNOFF -PRODUCING RAINFALL EVENT. ANY NECESSARY REPAIRS OR CLEANUP TO MAINTAIN THE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL BE MADE IMMEDIATELY. Peabody School Erosion/Sediment Control Narrative September 19, 2005 PROJECT DESCRIPTION The project consists of construction of a classroom addition to replace existing temporary classrooms and new multi-purpose budding. The total disturbance for this site is 0.9 acres. EXISTING SITE CONDITIONS The school exists on site and most of the area In the vicinity of the addition has been previously cleared. ADJACENT PROPERTY TMP 76M(1) . 16 (Carolina Builders) is to the north, Stoney Ridge Road (Rt 1000), to the east, Southern Parkway (Rt 1165) to the south and an tntermittenl: stream and Foxcroft Subdivision to the west. OFFSITE AREAS No off-site areas will b;; disturbed. SOILS undorthents, loamy CRITICAL EROSION AREAS. There are no critical erosion areas. EROSION AND SEDIMENT CONTROL MEASURES Unless otherwise indicated, all vegetative and structural erosion and sediment control practices will be constructed and maintained according to minimum standards and specifications of the Virginia Erosion and Sediment Control Handbook (VESCH). STRUCTURAL PRACTICES 1. Construction Entrance- 3.02 A temporary paved construction entrance shall be, installed at the beginning of the project. 2. Silt Fence- 3.05 A temporary sediment barrier consisting of a synthetic filter fabric stretched across and attached to supporting posts and entrenched. 3. Outlet Protection - 3.18 Rlprchannel and/or si.;illing basins below storm drain outlets. Outlet protection shall be Installed on the outlet pipe as shown on the F8SC plan immediately after installation. 4. Inlet Protection 33X77 A sediment filter or an excavated impounding area around a storm drain drop inlet or curb inlet. Inlet protection shall be installed on the inlets Immediately -after installation to prevent Sediment compromisinge: tiolr capacity. VEGETATIVE PRACTIC(-S 1. Temporary Seeding - 3.31 Establishment of temporory vegetative cover on disturbed areas by seeding with appropriate rapidly growing plants on sites that will not be brought to final grade for periods of 30 days to one year. German Millet at 60 Ib./ac., Weeping Lovegrass at 3 Ib./ac., Korean Lespedezo at 20 Ib./ac. Temporary seeding shall be fertilized. Fertilizer shall be applied at a rate of 600 lbs/acre of 10-20-10 according to the handbook. The builder may save considerable funds by having the sod tested by VA TECH (kits are available at the extension office and the test Casts $6.00). 2. Mulch - 3.35 Organic mulch shall be u;;ad in conjunction with seeding operations and shall be applied at the rate of 2 tons/acre, 3. Dust Control- 3.39 Dust control Measures shall be utilized throughout this site when necessary. Typical measures Include but are not limited to, irrigation, temporary seeding barriers. These measures will aid to 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 step 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 sending 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 @ Sediment Control Handbook. 5-20-10 fertilizer shall be applied at the rate of 1000 Ib/ac and lime at 2 tons/ac. Permanently seeded areas shall be protected during establishment with straw mulch (2 tons/ac). MAINTENANCE In general, 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 Gleaned and maintained according to the VESCH. 2) All gravel outlets will be checked 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 fence will be checked regularly for undermining or deterioration of the fabric and repaired as required. Sediment shall be removed when the level of sediment deposition reaches half way to the top of the barrier. 4) All seeded areas will be checked regularly to see that a good stand is maintained. Areas should be fertilized and reseeded as needed. MS -1 Stabilization of Denuded Areas and Sod Stockpiles Permanent or temporary soil stabilization must be app(led to denuded areas within seven days after final grade is reached on any portion of the site. Temporary sod stabilization shall be opIced within seven days to denuded areas that may not be at final grade, but will remain dormant (undisturbed) for longer than O days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year. Soil stabilization refers I:o measure which protect soil from the erosive forces of raindrop Impact and flowing water. Applicable practicns Include vegetative establishment, mulching, and the early application of gravel base on areas to be paved. Soil stablllzation measures should be selected to be operapdate for the time of year, site conditions and estimated duration of use. MS -4 Timing and stabdl:tatton of Sediment Trapping Measures Sediment basins and traps, perimeter dikes, sediment barriers and other measures Intended to trap sediment shall be constructed as a first step in any land-di.turbing activity and shall be made functional before up-slope land disturbance takes place. MS- 5 Stabilization Mcoz;ures Stabilization measures shall be applied to earthen structures 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 and of each day. Sediment shall be removed from the roads by shoveling or sweeping and transported to a sediment control disposal area. Greet 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. r> 3 WEIR TO 8E GROUTED WHEN SILT TRAP TOP OF BERM = 444' IS CONVERTED TO PIMP 2: 1 2: 1 SOD TURF COVER TOP OF WEIR = 443.2' J _ 2.5:1 CLAN -OUT W/WATERTIGHT CAP 44250/50' III -III (I I -I I ' TOPSOIL & SAND Contractor shall contact the woter resources Inspector 24 hours prior III=1 I=III=III=III 91 1=111 --SAND: 0.02-0.04" to backfilling the biofilter and request an Inspection and approval of IEI -I I IEI El I 1=1IEI 2. 0' ( MUSTSTM BE INSPECTED) BY the underdram mstallatmo and the soil mix. III-III-) -III EROSION COWATER ONTROL INSPECTOR) 6" NDN -PERFORATED see note #2 below) PVC PIPE AT 1% HT 4'-6" PERF ED UNOERDRAIN GRAVEL BIOFILTER CROSS SECTIONPVCPIPEAT17: (AASHTO M4=', 1/2"-1") SLOPE (MIN) WRAPPED IN FILTER FABRIC STORMWATER/BMP NOTES 1 B P atfav S ite bg'cong rutted until the site is adequately stabilized, according to Water Resources Personnel (434-296-5861) 2 €Tstjg ltr 3 i,1}ter sc %2 mi.?i lnp be the Luck Bia-filter Mix available from Luck Stone or a tested and approved equivalent. For' addional znf;orlasr c'o,ntact Water Resoruces Personnel (434-295-5861) . 3. The sand/soil mix musty lie stabilized with sod along with the trees and/or shrubs listed on the plan. FE8 1 GRAPHIC SCALE 1"=20' 0 ;D0 4n Fn E&SC LEGEND LO Z ENSC STD, G SPEC. CE TEMP. STONE CONST. ENTRANCE 3.02 SF SILT FENCE 3.05 CIP CULVERT INLET PROTECTION 3.08 DD TEMPORARY DIVERSION DIKE 3.09 ST TEMPORARY SEDIMENT TRAP 3.13 TSD TEMPORARY SLOPE DRAIN 3.15 OP OUTLET PROTECTION 3.18 CD ROCK CHECK DAMS 3.20' LS LEVEL SPREADER 3.21. TO TOPSOILING 3.30' TS TEMPORARY SEEDING 3.31 PS PERMANENT SEEDING 3.321 SO SODDING 3.33 MU MULCHING 3.35 8/M SOIL STABILIZATION BLANKETS/MATTING 3.36 DC DUST CONTROL 3.39 CHARLOTTESVILLE I - 64 / O SITE Q y V2 VICINITY MAP / 1' = 2000'1. GENERAL EROSION AND SEDIMENT CONTROL NOTES ES -1: UNLESS OTHERWISE INDICATED, ALL VEGETATIVE AND STRUCTURAL EROSION AND SEDIMENT CONTROL PRACTICES WILL BE CONSTRUCTED AND MAINTAINED ACCORDING TO MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK AND VIRGINIA REGULATIONS VR 625-02-00 EROSION AND SEDIMENT CONTROL REGULATIONS. ES-,?: THE PLAN APPROVING AUTHORITY MUST BE NOTIFIED ONE WEEK PRIOR TO THE PRE - CONSTRUCTION CONFERENCE, ONE WEEK PRIOR TO THE COMMENCEMENT OF LAND DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPECTION. ES -:3: ALL EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE PLACED PRIOR TO OR AS THE FIRST STEP IN CLEARING. ES -4: A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL PLAN SHALL BE MAINTAINED ON THE SITE AT ALL TIMES. ES -5: PRIOR TO COMMENCING LAND DISTURBING ACTIVITIES IN AREAS OTHER THAN INDICATED ON THESE PLANS (INCLUDING, BUT NOT LIMITED TO, OFF-SITE BORROW OR WASTE AREAS), THE CONTRACTOR SHALL SUBMIT A SUPPLEMENTARY EROSION CONTROL PLAN TO THE OWNER FOR REVIEW AND APPROVAL BY THE PLAN APPROVING AUTHORITY. ES -6: THE CONTRACTOR IS RESPONSIBLE FOR INSTALLATION OF ANY ADDITIONAL EROSION CONTROL MEASURES NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS DETERMINED BY THE PLAN APPROVING AUTHORITY. ES -7: ALL DISTURBED AREAS ARE TO DRAIN TO APPROVED SEDIMENT CONTROL MEASURES AT ALL TIMES DURING LAND DISTURBING ACTIVITIES AND DURING SITE DEVELPMENT UNTIL FINAL STABILIZATION IS ACHIEVED. ES -H: DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED FILTERING DEVICE. ES -9: THE CONTRACTOR SHALL INSPECT ALL EROSION CONTROL MEASURES PERIODICALLY AND AFTER EACH RUNOFF -PRODUCING RAINFALL EVENT. ANY NECESSARY REPAIRS OR CLEANUP TO MAINTAIN THE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL BE MADE IMMEDIATELY. Peabody School Erosion/Sediment Control Narrative September 19, 2005 PROJECT DESCRIPTION The project consists of construction of a classroom addition to replace existing temporary classrooms and new multi-purpose budding. The total disturbance for this site is 0.9 acres. EXISTING SITE CONDITIONS The school exists on site and most of the area In the vicinity of the addition has been previously cleared. ADJACENT PROPERTY TMP 76M(1) . 16 (Carolina Builders) is to the north, Stoney Ridge Road (Rt 1000), to the east, Southern Parkway (Rt 1165) to the south and an tntermittenl: stream and Foxcroft Subdivision to the west. OFFSITE AREAS No off-site areas will b;; disturbed. SOILS undorthents, loamy CRITICAL EROSION AREAS. There are no critical erosion areas. EROSION AND SEDIMENT CONTROL MEASURES Unless otherwise indicated, all vegetative and structural erosion and sediment control practices will be constructed and maintained according to minimum standards and specifications of the Virginia Erosion and Sediment Control Handbook (VESCH). STRUCTURAL PRACTICES 1. Construction Entrance- 3.02 A temporary paved construction entrance shall be, installed at the beginning of the project. 2. Silt Fence- 3.05 A temporary sediment barrier consisting of a synthetic filter fabric stretched across and attached to supporting posts and entrenched. 3. Outlet Protection - 3.18 Rlprchannel and/or si.;illing basins below storm drain outlets. Outlet protection shall be Installed on the outlet pipe as shown on the F8SC plan immediately after installation. 4. Inlet Protection 33X77 A sediment filter or an excavated impounding area around a storm drain drop inlet or curb inlet. Inlet protection shall be installed on the inlets Immediately -after installation to prevent Sediment compromisinge: tiolr capacity. VEGETATIVE PRACTIC(-S 1. Temporary Seeding - 3.31 Establishment of temporory vegetative cover on disturbed areas by seeding with appropriate rapidly growing plants on sites that will not be brought to final grade for periods of 30 days to one year. German Millet at 60 Ib./ac., Weeping Lovegrass at 3 Ib./ac., Korean Lespedezo at 20 Ib./ac. Temporary seeding shall be fertilized. Fertilizer shall be applied at a rate of 600 lbs/acre of 10-20-10 according to the handbook. The builder may save considerable funds by having the sod tested by VA TECH (kits are available at the extension office and the test Casts $6.00). 2. Mulch - 3.35 Organic mulch shall be u;;ad in conjunction with seeding operations and shall be applied at the rate of 2 tons/acre, 3. Dust Control- 3.39 Dust control Measures shall be utilized throughout this site when necessary. Typical measures Include but are not limited to, irrigation, temporary seeding barriers. These measures will aid to 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 step 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 sending 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 @ Sediment Control Handbook. 5-20-10 fertilizer shall be applied at the rate of 1000 Ib/ac and lime at 2 tons/ac. Permanently seeded areas shall be protected during establishment with straw mulch (2 tons/ac). MAINTENANCE In general, 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 Gleaned and maintained according to the VESCH. 2) All gravel outlets will be checked 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 fence will be checked regularly for undermining or deterioration of the fabric and repaired as required. Sediment shall be removed when the level of sediment deposition reaches half way to the top of the barrier. 4) All seeded areas will be checked regularly to see that a good stand is maintained. Areas should be fertilized and reseeded as needed. MS -1 Stabilization of Denuded Areas and Sod Stockpiles Permanent or temporary soil stabilization must be app(led to denuded areas within seven days after final grade is reached on any portion of the site. Temporary sod stabilization shall be opIced within seven days to denuded areas that may not be at final grade, but will remain dormant (undisturbed) for longer than O days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year. Soil stabilization refers I:o measure which protect soil from the erosive forces of raindrop Impact and flowing water. Applicable practicns Include vegetative establishment, mulching, and the early application of gravel base on areas to be paved. Soil stablllzation measures should be selected to be operapdate for the time of year, site conditions and estimated duration of use. MS -4 Timing and stabdl:tatton of Sediment Trapping Measures Sediment basins and traps, perimeter dikes, sediment barriers and other measures Intended to trap sediment shall be constructed as a first step in any land-di.turbing activity and shall be made functional before up-slope land disturbance takes place. MS- 5 Stabilization Mcoz;ures Stabilization measures shall be applied to earthen structures 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 and of each day. Sediment shall be removed from the roads by shoveling or sweeping and transported to a sediment control disposal area. Greet 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. r> 3 WEIR TO 8E GROUTED WHEN SILT TRAP TOP OF BERM = 444' IS CONVERTED TO PIMP 2: 1 2: 1 SOD TURF COVER TOP OF WEIR = 443.2' J _ 2.5:1 CLAN -OUT W/WATERTIGHT CAP 44250/50' III -III (I I -I I ' TOPSOIL & SAND Contractor shall contact the woter resources Inspector 24 hours prior III=1 I=III=III=III 91 1=111 --SAND: 0.02-0.04" to backfilling the biofilter and request an Inspection and approval of IEI -I I IEI El I 1=1IEI 2. 0' ( MUSTSTM BE INSPECTED) BY the underdram mstallatmo and the soil mix. III-III-) -III EROSION COWATER ONTROL INSPECTOR) 6" NDN -PERFORATED see note #2 below) PVC PIPE AT 1% HT 4'-6" PERF ED UNOERDRAIN GRAVEL BIOFILTER CROSS SECTIONPVCPIPEAT17: (AASHTO M4=', 1/2"-1") SLOPE (MIN) WRAPPED IN FILTER FABRIC STORMWATER/BMP NOTES 1 B P atfav S ite bg'cong rutted until the site is adequately stabilized, according to Water Resources Personnel (434-296-5861) 2 €Tstjg ltr 3 i,1}ter sc %2 mi.?i lnp be the Luck Bia-filter Mix available from Luck Stone or a tested and approved equivalent. For' addional znf;orlasr c'o,ntact Water Resoruces Personnel (434-295-5861) . 3. The sand/soil mix musty lie stabilized with sod along with the trees and/or shrubs listed on the plan. FE8 1 GRAPHIC SCALE 1"=20' 0 ;D0 4n Fn DESIGNED BY DATE LO Z LU rnr, CD TM m m m CHECKED BY DATE FILE o PEA80DY CU LLJ J a H C-) Wi- OF 1 t - OJ2 0 a E IR GO Q m 4 CL ti DESIGNED BY DATE LO Z LU DATE TM 9/26/05 CHECKED BY DATE FILE EDIT PEA80DY LLJ In a PLOT C-) OF 1 Q 0 I l- --d Q Z CL M j m CG CD CC U CnZ H E U U 2: C H CE rT- z in 0 0 Lc cn H U r-1. I J M U w If rT- If r E: 0 0 U r\ Z M 1EL r LID tl O Q 0 o 0 w L o i - w Q ao o N C: I E C EO E CCJE m O J ZU OL N ti Y H n wo= C0_ w m cn U CLU 07171cvz DESIGNED BY DATE LO Z DRAWN BY DATE TM 9/26/05 CHECKED BY DATE FILE EDIT PEA80DY LLJ In 1: 1 PLOT C-) OF 1 Q M I l- --d Q Z CL M j U CG CD CC U III Z H U U 2: C J CE rT- z 0 0 Lc cn U r-1. I J M U If rT- W r E: C_O 0 U r\ M 1EL r Z Q 0 H U) X0 Q DESIGNED BY DATE TM 9/28/05 DRAWN BY DATE TM 9/26/05 CHECKED BY DATE FILE EDIT PEA80DY SCALE 1: 20; 2' CI DRAWING 1: 1 PLOT PROJECT - OF 1 SHEET NO.