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HomeMy WebLinkAboutWPO201800027 Plan - VSMP 2020-06-05MARTHA JEFFERSON HOSPITAL PRESIDIO APARTMENTS GENERAL NOTES OWNER: PRESIDIO PANTOPS, LLC 455 SECOND ST SE, SUITE 201 CHARLOTTESVILLE, VA 22902 DEVELOPER: CASTLE DEVELOPMENT PARTNERS, LLC 230 COURT SQUARE, SUITE 202 CHARLOTTESVILLE, VA 22902 ENGINEER: COLLINS ENGINEERING 200 GARRETT ST, SUITE K CHARLOTTESVILLE, VA 22902 (434) 293-3719 TAX MAP NO.: 07800-00-00-02OM6 DB 5224 PG 198 TOTAL PROJECT AREA: 26.98 ACRES TOTAL ZONING: PLANNED DEVELOPMENT MIXED COMMERCIAL WITH PROFFERS (ZMA 01-015), PRESERVED AND MANAGED STEEP SLOPES OVERLAY AREA. 100 YR FLOODPLAIN OVERLAY DISTRICT TOPO & SURVEY: SURVEY PROVIDED BY ROUDABUSH & GALE DATED JUNE, 2017. TOPOGRAPHY IS AERIAL SURVEY PERFORMED BY VIRGINIA RESOURCE MAPPING DATED JANUARY, 2006. TOPO FIELD VERIFIED BY COLLINS ENGINEERING PRIOR TO CONSTRUCTION. DATUM: NAD83, NAVD 88 PRE -CONSTRUCTION TERRAIN: UNDEVELOPED PROPERTY SLOPING DOWN TOWARD THE RIVANNA RIVER AND INTERSTATE 64. PRE -CONSTRUCTION VEGETATION: WOODED WATER SUPPLY PROTECTION AREA: N/A WATERSHED / WATER RESOURCE AREA: RIVANNA RIVER DRAINAGE BASIN UTILITIES (WATER AND SEWER): COUNTY PUBLIC WATER AND SANITARY SEWER AGRICULTURAL/ FORESTAL DISTRICT: NONE PHASING: THIS SITE SHALL BE DEVELOPED IN ONE PHASE. STREAM BUFFERS/FLOODPLAIN: THE STREAM BUFFERS SHOWN HEREIN SHALL BE MANAGED IN ACCORDANCE WITH THE ALBEMARLE COUNTY WATER PROTECTION ORDINANCE. THIS PARCEL IS WITHIN ZONE X "AREA OF MINIMAL FLOOD HAZARD", PER FEMA MAP NUMBER 51003CO289D ADOPTED FEBRUARY 4, 2005. NO IMPACTS ARE PROPOSED FOR THE 100 YEAR FLOODPLAIN. THE PROPERTY IS WITHIN A STATE DAM INUNDATION ZONE AND FEDERAL DAM INUNDATION ZONE ALONG THE RIVANNA RIVER. ALL PROPOSED DEVELOPMENT SHALL BE LOCATED OUTSIDE OF THE LIMITS OF THE INUNDATION ZONES. CRITICAL SLOPES: MANAGED STEEP SLOPES AND PRESERVED STEEP SLOPES ARE EXISTING ON SITE AS SHOWN ON THE PLAN. IMPACTS TO MANAGED SLOPES ARE CONSISTENT WITH THE ALBEMARLE COUNTY ZONING ORDINANCE. NO IMPACTS ARE PROPOSED TO THE EXISTING PRESERVED SLOPES. BURIAL SITES: NO CEMETERIES WERE FOUND DURING FIELD INVESTIGATION OF THE SITE. STORMWATER MANAGEMENT: A LEVEL II WET POND IS PROPOSED WITH THIS DEVELOPMENT. THE WET POND WILL PROVIDE STORMWATER QUALITY AND QUANTITY TREATMENT FOR THE MAJORITY OF THE PROPOSED IMPROVEMENTS. THE VAST MAJORITY OF THE REMAINING PROPOSED IMPROVEMENTS WILL RECEIVE STORMWATER QUANTITY TREATMENT VIA A PROPOSED DRY DETENTION CELL. A LEVEL II BIORETENTION BASIN IS ALSO PROPOSED FOR WATER QUALITY TREATMENT. THE REMAINING WATER QUALITY REQUIREMENTS WILL BE MET THROUGH THE BEST MANAGEMENT PRACTICE OF PURCHASING NUTRIENT CREDITS. VSMP PLAN AMENDMENT #1 PROPOSED CHANGES TO WPO 201800027: SHEET 1 1. THE'STORMWATER MANAGEMENT' SECTION OF SHEET 1's GENERAL NOTES WAS UPDATED. 2. THE SHEET INDEX AND TITLE WERE REVISED. THE BORDER TITLES WERE ALSO REVISED. SHEET 2 3. THE APPROVED VSMP's SHEET 2 WAS REPLACED WITH SHEET 2 FROM THE SDP 201900075 CURRENTLY UNDER REVIEW. SHEET 3 4. THE 'EROSION CONTROL NOTES & NARRATIVE' SECTION WAS UPDATED TO REFLECT THE ADDITION OF EROSION & SEDIMENT CONTROL PHASES II AND III. SHEET 4 5. APPROVED SEDIMENT TRAP #1 BECAME PROPOSED SEDIMENT BASIN #2. THIS TEMPORARY SEDIMENT TRAPPING FACILITY WAS ENLARGED TO MATCH THE FOOTPRINT OF THIS AMENDMENT's ENLARGED PERMANENT DRY DETENTION CELL. 6. A NEW SEDIMENT TRAP, NOW LABELED SEDIMENT TRAP #1 WITH THIS AMENDMENT, HAS BEEN ADDED. 7. THE LOCATIONS OF THE CONTRACTOR PARKING AREA, STAGING AREA, PORTA POTTIES, DUMPSTER AND FUELING TANK WERE SHIFTED SLIGHTLY TO REMAIN IN THE SAME LOCATION FOR A LONGER PERIOD OF TIME (i.e. TO REMAIN IN THE SAME LOCATION THROUGH THE BULK OF THE MASS GRADING OPERATIONS SHOWN IN ESC PHASE II). SHEETS 4A & 413 8. SHEETS 4A & 413 WERE ADDED TO THIS AMENDMENT TO PROVIDE A PHASE II AND PHASE III EROSION & SEDIMENT CONTROL PLAN. 9. THE LIMITS OF DISTURBANCE INCREASED WITH THE ADDITION OF ESC PHASES II AND III. SHEET 5 10. THE CALCULATIONS AND DETAIL FOR SEDIMENT BASIN #2 (FORMERLY SEDIMENT TRAP #1) WERE UPDATED. SHEET 6 11. THE APPROVED DRY DETENTION CELL (PROVIDING STORMWATER QUANTITY, NOT QUALITY TREATMENT) WAS ENLARGED AND THE PREVIOUSLY APPROVED UNDERGROUND DETENTION SYSTEM WAS REMOVED. THESE REVISIONS DO NOT IMPACT POST -DEVELOPMENT SUBAREA A IN THE APPROVED STORMWATER MANAGEMENT PLAN. THIS AMENDMENT PROVIDES ACCOMPANYING CALCULATIONS SHOWING CONTINUED STORMWATER QUANTITY COMPLIANCE FOR SUBAREA B. 12. WITH THE INCREASE IN THE LIMITS OF DISTURBANCE NOTED ABOVE, REVISED WATER QUALITY CALCULATIONS HAVE BEEN PROVIDED. THE AMENDMENT REQUIRES AN ADDITIONAL 0.44 Ibs/yr. OF PHOSPHOROUS REMOVAL, WHICH IS MITIGATED THROUGH THIS AMENDMENT's PROPOSED BIORETENTION BASIN SHOWN ON SHEET 8A. 13. SUBAREA C WAS REMOVED FROM THE ANALYSIS. THE APPROVED PLAN RELEASED UNCAPTURED RUNOFF FROM THE SOUTHWESTERN MOST PORTION OF THIS DEVELOPMENT (i.e. THE SOUTH WESTERN MOST PARKING LOT). THE SDP 201900075 CURRENTLY UNDER REVIEW NOW PROPOSES INLETS AT THE PERIMETER OF THE PARKING LOT/SUBAREA B AND DIRECTS THIS RUNOFF TO THE DRY DETENTION CELL. SHEET 7 14. NO REVISIONS WERE REQUIRED TO THE APPROVED LEVEL II WET POND PROVIDING STORMWATER QUANTITY AND QUALITY TREATMENT, OTHER THAN THE ADDITION OF TWO SIGNS AND AERATION. SHEET 8 15. THE UNDERGROUND DETENTION SYSTEM's DETAILS WERE REMOVED. 16. THE APPROVED DRY DETENTION CELL PROVIDING STORMWATER QUANTITY TREATMENT FOR SUBAREA B WAS ENLARGED AND THE DETAIL AND PROFILES WERE UPDATED. THE FACILITY WAS ENLARGED TO COMPENSATE FOR THE REMOVAL OF THE UNDERGROUND DETENTION SYSTEM. SHEET 8A 17. THIS SHEET WAS ADDED TO DETAIL THE DESIGN OF THE ONSITE LEVEL II BIORETENTION BASIN #1. SHEET 9 18. THE UNDERGROUND DETENTION SYSTEM DETAILS WERE REMOVED FROM THIS SHEET. VSMP PLAN (AMENDMENT #1 TO WPO201800027) RIVANNA MAGISTERIAL DISTRICT ALBEMARLE COUNTY, VIRGINIA SHEET LAYOUT SHEET INDEX SCALE: _ 1„ - 100, TITLE SHEET COVER 1 EXISTING CONDITIONS 2 EROSION & SEDIMENT CONTROL PLAN NARRATIVE 3 APPROVED EROSION & SEDIMENT CONTROL PLAN 4 by the Albemarle County PHASE II EROSION & SEDIMENT CONTROL PLAN 4A Community Development Department PHASE III EROSION & SEDIMENT CONTROL PLAN 4B Date 06/05/2020 EROSION & SEDIMENT CONTROL DETAILS & CALCULATIONS 5 File WP0201800027 STORMWATER MANAGEMENT PLAN 6 Amendment #1 LEVEL II WET POND DETAILS 7 DRY DETENTION CELL DETAILS 8 LEVEL II BIORETENTION BASIN DETAILS 8A GENERAL STORMWATER MANAGEMENT NOTES & DETAILS 9 TOTAL SHEETS 12 CD 0 C�� o ELF �pGT SAP �JF y�/p 2'rO e0 �NTERST ATE 64 VICINITY MAP SCALE: 1" = 1000' EROSION CON TROL * VIRGINIA EROSION & SEDIMENT HANDBOOK SPECIF CA TION NUMBER CONTROL STB1=1 STRAW BAIL BARRIER 3.04 D V 08 I.DD TEMPORARY DIVERSION DIKE 3.09 ST moma°o�♦ TEMPORARY SEDIMENT TRAP 3.I3 SB COD SEDIMENT BASIN 3.14 lP INLET PROTECTION 3.07 SFX SILT FENCE 3.05 x X CEO 0 o CONSTRUCTION ENTRANCE 3.02 CD ' CHECK DAM 3.20 FD TEMPORARY FILL DIVERSION 3.10 D V DI VERSION 3.12 PS_-8- PS PERMANENT SEEDING 3.32 TO TO TOPSOILING 3.30 ClP CULVERT INLET PROTECTION 3.08 DC DC DUST CONTROL 3.39 TSD TEMPORARY SLOPE DRAIN 3.15 - SA SAFETY FENCE 3.01 RW PI TEMPORARY RIGHT-OF-WAY 3.11 DIVERSION EXISTING CULVERT A DROP INLET & STRUCTURE NO. CURB CURB & GUTTER PROPOSED ASPHAL T PROPOSED CONCRETE PROPOSED PAVER (IMPERVIOUS) BENCH MARK VDOT STANDARD STOP SIGN EXISTING CONTOUR PRESERVED STEEP SLOPES MANAGED STEEP SLOPES -OkR..L �6 i '! SC0TLINS� L� No. 35791 .1�1 6/1/20 o��SSIONAL E��Z Z z aQ o�� m LUc'n 0 J O H cn z LULU co Cle) N Nt M 17 in z LU w rl LU M LU Q z Q () () z LU Q LU Q / O U Q 1_ - LU J U) 0 z 0 LU LL w r'1 Q I LU w U) JOB NO. 172131 SCALE AS SHOWN SHEET NO. 1 o / _ � NOTES: \ 1. THIS PROJECT IS LOCATED WITHIN FLOODPLAIN LIMITS, BASED ON FEMA MAP ; 0 / NUMBER 51003CO289D ADOPTED FEBRUARY 4, 2005. 1 MATCHLINE A - Slit THIS SHEET Q / ���C NC 40g1 ��� �� Q BENCHMARK = EX(STI G/ 2. SURVEY PROVIDED BY ROUDABUSH &GALE DATED JUNE, 2017. TOPOGRAPHY IS Q 440.000 40 N ( AERIAL SURVEY PERFORMED BY VIRGINIA RESOURCE MAPPING DATED JANUARY i �� EXISTI DRAINA 48 I EX.DI V,310 312, R= Q SANITARY SEWER'MANHO E o 2006. TOPO FIELD VERIFIED BY COLLINS ENGINEERING IN JANUARY 2018. I INLETS TYPICAL) co 1 ? TOP ELEV = 446.92 SCOTT R. LINS ` r Q 3. MANAGED AND PRESERVED STEEP SLOPES ARE LOCATED ON THE PROPERTY. / j /� / Q I I �X�k\ u CD \ U � \ .DI 4. 100' WPO STREAM BUFFER IS SHOWN. THE STREAM BUFFER SHOWN HEREON Lu DI No. 35791 Q Q EXISTING MH-MJH-1-4 SHALL BE MANAGED IN ACCORDANCE WITH THE ALBEMARLE COUNTY WATER r i / f EX.DI dry, 6/1/20 \x.Di PROTECTION ORDINANCE. /� N Q / / rn Q o CONC 1Lo/ \ /r � ti EXISTI DRAINAGE INLET ICAL) r / / / \ \ c�/ r - C 9g� Q / / TMP. 07800 00 00 031H0 EXISTI AND GUTTER ko EX. 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STRUCTURAL PRACTICES USED IN THIS SECTION CONSIST OF THE FOLLOWING: 3.01 SAFETY FENCE: A PROTECTIVE BARRIER INSTALLED TO PREVENT ACCESS TO AN EROSION CONTROL MEASURE. TO PROHIBIT THE UNDESIRABLE USE OF AN EROSION CONTROL MEASURE BY THE PUBLIC. APPLICABLE TO ANY CONTROL MEASURE OR SERIES OF MEASURES WHICH CAN BE CONSIDERED UNSAFE BY VIRTUE OF POTENTIAL ACCESS BY THE PUBLIC. 3.02 CONSTRUCTION ENTRANCE: A STABILIZED PAVED CONSTRUCTION ENTRANCE WITH A WASH RACK LOCATED AT POINTS OF VEHICULAR INGRESS AND EGRESS ON A CONSTRUCTION SITE. TO REDUCE THE AMOUNT OF MUD TRANSPORTED ONTO PAVED PUBLIC ROADS BY MOTOR VEHICLES OR RUNOFF. CONSTRUCTION ENTRANCES SHALL BE INSTALLED AS SHOWN ON THE PLANS TO REDUCE THE AMOUNT SEDIMENT TRANSPORTED ONTO PUBLIC ROADWAYS. 3.05 SILT FENCE.• A TEMPORARY SEDIMENT BARRIER CONSISTING OF A SYNTHETIC FILTER FABRIC STRETCHED ACROSS AND ATTACHED TO SUPPORTING POSTS AND ENTRENCHED, TO INTERCEPT AND DETAIN SMALL AMOUNTS OF SEDIMENT FROM DISTURBED AREAS DURING CONSTRUCTION OPERATIONS IN ORDER TO PREVENT SEDIMENT FROM LEAVING THE SITE, AND TO DECREASE THE VELOCITY OF SHEET FLOWS AND LOW- TO-MODERA TE LEVEL CHANNEL FLOWS. THE SILT FENCE BARRIERS SHALL BE INSTALLED DOWN SLOPE OF AREAS WITH MINIMAL GRADES TO FILTER SEDIMENT LADEN RUNOFF FROM SHEET FLOW AS INDICATED. THEY SHALL BE INSPECTED IMMEDIATELY AFTER EACH RAINFALL AND MAINTAINED IN ACCORDANCE WITH THE VIRGINIA EROSION & SEDIMENT CONTROL HANDBOOK (VESCH). 307 STORM DRAIN INLET PROTECTION: A SEDIMENT FILTER OR AN EXCAVATED IMPOUNDING AREA AROUND A STORM DRAIN DROP INLET OR CURB INLET. TO PREVENT SEDIMENT FROM ENTERING STORM DRAINAGE SYSTEMS PRIOR TO PERMANENT STABILIZATION OF THE DISTURBED AREA. INLET PROTECTION APPLIES WHERE STORM DRAIN INLETS ARE TO BE MADE OPERATIONAL BEFORE PERMANENT STABILIZATION OF THE CORRESPONDING DISTURBED DRAINAGE AREA. 3.09 TEMPORARY DIVERSION DIKE.• A TEMPORARY RIDGE OF COMPACTED SOIL CONSTRUCTED AT THE TOP OR BASE OF A SLOPING DISTURBED AREA. TO DIVERT STORM RUNOFF FROM UPSLOPE DRAINAGE AREAS AWAY FROM UNPROTECTED DISTURBED AREAS AND SLOPES TO A STABILIZED OUTLET. TO DIVERT SEDIMENT -LADEN RUNOFF FROM A DISTURBED AREA TO A SEDIMENT -TRAPPING FACILITY SUCH AS A SEDIMENT TRAP OR SEDIMENT BASIN. USE WHEREVER STORMWATER RUNOFF MUST BE TEMPORARILY DIVERTED TO PROTECT DISTURBED AREAS AND SLOPES OR RETAIN SEDIMENT ON SITE DURING CONSTRUCTION. THESE STRUCTURES GENERALLY HAVE A LIFE EXPECTANCY OF 18 MONTHS OR LESS, WHICH CAN BE PROLONGED WITH PROPER MAINTENANCE. 312 DI VERSION: A CHANNEL CONSTRUCTED ACROSS A SLOPE WITH A SUPPORTING EARTHEN RIDGE ON THE LOWER SIDE. TO REDUCE SLOPE LENGTH AND TO INTERCEPT AND DIVERT STORMWATER RUNOFF TO STABILIZED OUTLETS AT NON -EROSIVE VELOCITIES. APPLIES WHERE RUNOFF FROM AREAS OF HIGHER ELEVATION MAY DAMAGE PROPERTY, CAUSE EROSION, OR INTERFERE WITH THE ESTABLISHMENT OF VEGETATION ON LOWER AREAS, WHERE SURFACE AND/OR SHALLOW SUBSURFACE FLOW IS DAMAGING SLOPING UPLAND, AND WHERE THE SLOPE LENGTH NEEDS TO BE REDUCED TO MINIMIZE SOIL L OSS. 313 TEMPORARY SEDIMENT TRAP: A TEMPORARY PONDING AREA FORMED BY CONSTRUCTING AN EARTHEN EMBANKMENT WITH A STONE OUTLET. TO DETAIN SEDIMENT -LADEN RUNOFF FROM SMALL DISTURBED AREAS LONG ENOUGH TO ALLOW THE MAJORITY OF THE SEDIMENT TO SETTLE OUT. USE BELOW DISTURBED AREAS WHERE THE TOTAL CON TR/BU TING DRAINAGE AREA /S LESS THAN 3 ACRES, WHERE THE SEDIMENT TRAP WILL BE USED NO LONGER THAN 18 MONTHS, AND IT MAY BE CONSTRUCTED EITHER INDEPENDENTLY OR IN CONJUNCTION WITH A TEMPORARY DIVERSION DIKE. 314 TEMPORARY SEDIMENT BASIN: A TEMPORARY BARRIER OR DAM WITH A CONTROLLED STORMWATER RELEASE STRUCTURE FORMED BY CONSTRUCTING AN EMBANKMENT OF COMPACTED SOIL ACROSS A DRAINAGEWAY. TO DETAIL SEDIMENT -LADEN RUNOFF FROM DISTURBED AREAS IN "WET" AND `DRY" STORAGE LONG ENOUGH FOR THE MAJORITY OF THE SEDIMENT TO SETTLE OUT. APPLIES BELOW DISTURBED AREAS WHERE THE TOTAL CONTRIBUTING DRAINAGE AREA IS EQUAL TO OR GREATER THAN THREE ACRES. THERE MUST BE SUFFICIENT SPACE AND APPROPRIATE TOPOGRAPHY FOR THE CONSTRUCTION OF A TEMPORARY IMPOUNDMENT. 318 OUTLET PROTECTION: STRUCTURALL Y LINED APRONS OR OTHER ACCEPTABLE ENERGY D/SS/PA TING DEVICES PLACED A T THE OUTLETS OF PIPES OR PA VED CHANNEL SECTIONS. TO PREVENT SCOUR AT STORMWATER OUTLETS, TO PROTECT THE OUTLET STRUCTURE, AND TO MINIMIZE THE POTENTIAL FOR DOWNSTREAM EROSION BY REDUCING THE VELOCITY AND ENERGY OF CONCENTRATED STORMWA TER FLOWS. APPLICABLE TO THE OUTLETS OF ALL PIPES AND ENGINEERED CHANNEL SECTIONS. 319 RIPRAP: A PERMANENT, EROSION -RESISTANT GROUND COVER OF LARGE, LOOSE, ANGULAR STONE WITH FILTER FABRIC OR GRANULAR UNDERLINING. TO PROTECT THE SOIL FROM THE EROSIVE FORCES OF CONCENTRATED RUNOFF, SLOW THE VELOCITY OF CONCENTRATED RUNOFF WHILE ENHANCING THE PO TEN T/AL FOR INF/L TRA T/ON, AND TO STABILIZE SLOPES WITH SEEPAGE PROBLEMS, AND/OR NON -COHESIVE SOILS. USE WHEREVER SOIL AND WATER INTERFACE AND THE SOIL CONDITIONS, WATER TURBULENCE AND VELOCITY, EXPECTED VEGETATIVE COVER, ETC., ARE SUCH THAT THE SOIL MAY ERODE UNDER THE DESIGN FLOW CONDITIONS. 3.20 ROCK CHECK DAMS. -- SMALL TEMPORARY STONE DAMS CONSTRUCTED ACROSS A SWALE OR DRAINAGE DITCH. TO REDUCE THE VELOCITY OF CONCENTRATED STORMWATER FLOWS, THEREBY REDUCING EROSION OF THE SWALE OR DITCH. THIS PRACTICE ALSO TRAPS SEDIMENT GENERATED FROM ADJACENT AREAS OR THE DITCH ITSELF, MAINLY BY PONDING OF THE STORMWATER RUNOFF. THIS PRACTICE, UTILIZING A COMBINATION OF STONE SIZES, IS LIMITED TO USE IN SMALL OPEN CHANNELS WHICH DRAIN 10 ACRES OR LESS. 331 TEMPORARY SEEDING. THE ESTABLISHMENT OF A TEMPORARY VEGETATIVE COVER ON DISTURBED AREAS BY SEEDING WITH APPROPRIATE RAPIDLY GROWING ANNUAL PLANTS. TO REDUCE EROSION AND SEDIMENTATION BY STABILIZING DISTURBED AREAS THAT WILL NOT BE BROUGHT TO FINAL GRADE FOR A PERIOD OF MORE THAN 30 DAYS. TO REDUCE DAMAGE FROM SEDIMENT AND RUNOFF TO DOWNSTREAM OR OFF -SITE AREAS, AND TO PROVIDE PROTECTION TO BARE SOILS EXPOSED DURING CONSTRUCTION UNTIL PERMANENT VEGETATION OR OTHER EROSION CONTROL MEASURES CAN BE ESTABLISHED. 332 PERMANENT STABILIZATION: THE ESTABLISHMENT OF PERENNIAL VEGETATIVE COVER ON DISTURBED AREAS BY PLANTING SEED. TO REDUCE EROSION AND DECREASE SEDIMENT YIELD FROM DISTURBED AREAS. TO PERMANENTLY STABILIZE DISTURBED AREAS IN A MANNER THAT IS ECONOMICAL, ADAPTABLE TO SITE CONDITIONS, AND ALLOWS SELECTION OF THE MOST APPROPRIATE PLANT MATERIALS. TO IMPROVE WILDLIFE HABITAT. TO ENHANCE NATURAL BEAUTY. UPON COMPLETION OF CONSTRUCTION ACTIVITIES, ALL AREAS WILL RECEIVE A PERMANENT VEGETATIVE COVER. 335 MULCHING: APPLICATION OF PLANT RESIDUES OR OTHER SUITABLE MATERIALS TO THE SOIL SURFACE. TO PREVENT EROSION BY PROTECTING THE SOIL SURFACE FROM RAINDROP IMPACT AND REDUCING THE VELOCITY OF OVERLAND FLOW. TO FOSTER THE GROWTH OF VEGETATION BY INCREASING AVAILABLE MOISTURE AND PROVIDING INSULATION AGAINST EXTREME HEAT AND COLD. AREAS WHICH HAVE BEEN PERMANENTLY SEEDED SHOULD BE MULCHED IMMEDIATELY FOLLOWING SEEDING. AREAS WHICH CANNOT BE SEEDED BECAUSE OF THE SEASON SHOULD BE MULCHED USING ORGANIC MULCH. MULCH MAY BE USED TOGETHER WITH PLANTINGS OF TREES, SHRUBS, OR CERTAIN GROUND COVERS WHICH DO NOT PROVIDE ADEQUATE SOIL STABILIZATION BY THEMSELVES, CAN BE USED IN CONJUNCTION WITH TEMPORARY SEEDING. 337 TREES, SHRUBS. VINES & GROUND COVERS: STABILIZING DISTURBED AREAS BY ESTABLISHING VEGETATIVE COVER WITH TREES, SHRUBS, VINES, OR GROUND COVERS. TO AID IN STABILIZING SOIL /N AREAS WHERE VEGETATION OVER THAN TURF /S PREFERRED, TO PROVIDE FOOD AND SHELTER FOR WILDLIFE WHERE WILDLIFE HABITAT /S DESIRABLE. APPLIES /N AREAS WHERE TURF ESTABLISHMENT /S DIFFICULT, ON STEEP OR ROCKY SLOPES WHERE MOWING /S NOT FEASIBLE, WHERE ORNAMENTALS ARE DESIRABLE FOR LANDSCAPING PURPOSES, AND WHERE WOODY PLANTS ARE DESIRABLE FOR SOIL CONSERVATION, OR TO ESTABLISH WILDLIFE HABITAT. 3.38 TREE PRESERVATION AND PROTECTION: PROTECTION OF DESIRABLE TREES FROM MECHANICAL OR OTHER INJURY DURING LAND DISTURBING AND CONSTRUCTION ACTIVITY. TO ENSURE THE SURVIVAL OF DESIRABLE TREES WHERE THEY WILL BE EFFECTIVE FOR EROSION AND SEDIMENT CONTROL, WATERSHED PROTECTION, LANDSCAPE BEAUTIFICATION, DUST AND POLLUTION CONTROL, NOISE REDUCTION, SHADE AND OTHER ENVIRONMENTAL BENEFITS WHILE THE LAND IS BEING CONVERTED FROM FOREST TO URBAN -TYPE USES. APPLIES IN TREE -INHABITED AREAS SUBJECT TO LAND DISTURBING ACTIVITIES. 339 DUST CONTROL: REDUCING SURFACE AND AIR MOVEMENT OF DUST DURING LAND DISTURBING, DEMOLITION AND CONSTRUCTION ACTIVITIES. TO PREVENT SURFACE AND AIR MOVEMENT OF DUST FROM EXPOSED SOIL SURFACES AND REDUCE THE PRESENCE OF AIRBORNE SUBSTANCES WHICH MAY PRESENT HEALTH HAZARDS, TRAFFIC SAFETY PROBLEMS OR HARM ANIMAL OR PLANT LIFE. DUST CONTROL MEASURES SHALL BE EMPLOYED TO PREVENT SURFACE AND AIR MOVEMENT OF DUST DURING CONSTRUCTION. MEASURES EMPLOYED SHALL BE IN ACCORDANCE WITH THE VESCH. EROSION CONTROL * HANDBIOOK SEROPOCIFCATIONMENT NUMBERNTROL a STRAW BAIL BARRIER 3.04 I I I I Be TEMPORARY DIVERSION DIKE 3.09 ST t(%° o'BM4M TEMPORARY SEDIMENT TRAP 3.13 (SB) ® SEDIMENT BASIN 3.14 0INLET 0 PROTECTION 3.07 SFX SIL T FENCE 3.05 X X &c� oo 0 CONSTRUCTION ENTRANCE J. CD ' CHECK DAM 3.20 FD TEMPORARY FILL DIVERSION D V DIVERSION PS &_ S PERMANENT SEEDING TO TO --&- TOPSOILING ClP CULVERT INLET PROTECTION DC DC DUST CONTROL TSD TEMPORARY SLOPE DRAIN SA SAFETY FENCE 3.10 5.12 3.32 LEGEND ROADS A �._ 3.30 zoo 3.08 200 240.55 J. 0 3.15 3.01 RW TEMPORARY RIGHT -OF- WAY 3.11 pp,DIVERSION EROSION CONTROL NOTES ES-1: UNLESS OTHERWISE INDICATED, ALL VEGETA TI VE 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 VT 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 DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPECTION. ES-J.-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 SI TE A T 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 DEVELOPMENT UNTIL FINAL STABILIZATION IS ACHIEVED. ES-8.-DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED WATER 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. General construction notes for Erosion and Sediment Control plans 1. The plan approving authority must be notified one week prior to the re -construction P PP g y P P conference, one week prior to the commencement of land disturbing activity, and one week prior to the final inspection. 2. All erosion and sediment control measures 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. 3. All erosion and sediment control measures are to be placed prior to or as the first step in clearing. 4. A copy of the approved erosion and sediment control plan shall be maintained on the site at all times. 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. 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. 7. All disturbed areas are to drain to approved sediment control measures at all times during land disturbing activities and during site development until final stabilization is achieved. 8. During dewatering operations, water will be pumped into an approved filtering device. 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. 10. All fill material to be taken from an approved, designated borrow area. 11. All waste materials shall be taken to an approved waste area. Earth fill shall be inert materials only, free of roots, stumps, wood, rubbish, and other debris. 12. Borrow or waste areas are to be reclaimed within 7 days of completion per Zoning Ordinance section 5.1.28. 13. All inert materials shall be transported in compliance with section 13-301 of the Code of P P Albemarle. 14. Borrow, fill or waste activity involving industrial -type power equipment shall be limited to the hours of 7:00am to 9:00pm. 15. Borrow, fill or waste activity shall be conducted in a safe manner than maintains lateral support, or order to minimize any hazard to persons, physical damage to adjacent land and improvements, and damage to any public street because o slides, sinking, or collapse. 16. The developer shall reserve the right to install, maintain, remove or convert to permanent stormwater management facilities where applicable all erosion control measures required by this plan regardless of the sale of any lot, unit, building or other portion of the property- 17. Temporary stabilization shall be temporary seeding and mulching. Seeding is to be at 75 lbs/acre, and in the months of September to February to consist a 50150 mix of Annual Ryegrass and Cereal Winter Rye, or in March and April to consist of Annual Rye, or May through August to consist of German Millet. Straw mulch is to be applied at 801bs/100sf. Alternatives are subject to approved by the County erosion control inspector. 18. Permanent stabilization shall be lime and fertilizer, permanent seeding, and mulch - Agricultural g, A ricultural grade limestone shall be applied at 0lbs/1000sf, incorporated into the to 4-6 g g pp 9 rP p inches of soil. Fertilizer shall be applied at 10001bs/acre and consist of a 10-20-10 nutrient mix. Permanent seeding shall be applied at 180lbs/acre and consist of 95% Kentucky 31 or Tall Fescue and 0-5% Perennial Ryegrass or Kentucky Bluegrass. Straw mulch is to be applied at 801bs/100sf. Alternatives are subject to approved by the County erosion control inspector. 19. Maintenance: All measures are to be inspected weekly and after each rainfall. Any damage or clogging to structural measures is to be repair immediately. Silt traps are to be cleaned when 50% of the wet storage volume is filled with sediment. All seeded areas are to be reseeded when necessary to achieve a good stand of grass. Silt fence and diversion dykes which are collecting sediment to half their height must be cleaned and repaired immediately. 20. All temporary erosion and sediment control measures are to be removed within 30 days of final site stabilization, when measures are no longer needed, subject to approval by the County erosion control inspector. 21. This plan shall be void if the owner does not obtain a permit within 1 year of the date of approval. (Water Protection Ordinance section 17-204G.) 22. Permanent vegetation shall be installed on all denuded areas within nine (9) months after the date the land disturbing activity commenced. (Water Protection Ordinance section 17- 207B) TABLE 3.31-A LIMING REQUIREMENTS FOR TEMPORARY SITES Recommended Application RH Test of Agriculiural Limestone below 4.2 3 tons per acre 4.2 to 5.2 2 tons per acre 5.2 to 6 1 ton per acre Source: 'Va. DSWC GENERAL SLOPE (3:1 OR LESS) KENTUCKY 31 FESCUE RED TOP GRASS SEASONAL NURSE CROP EXISTING CULVERT CUL VERT DROP INLET & STRUCTURE NO. CURB CURB & GUTTER PROPOSED PA VEMEN T EC-3A DITCH DEPTH OF EC-3A DITCH EC-2 DI TCH DEPTH OF EC-2 DITCH EARTH DITCH DRl VEWA Y CUL VER T BENCH MARK CLEARING LIMITS VDOT STANDARD STOP SIGN EXISTING CONTOUR PROPOSED CONTOUR PROPOSED SPOT ELEVATION TBC DENOTES TOP/BACK OF CURB T/B DENOTES TOP OF BOX SEASONAL NURSE CROP FEBRUARY 16 THROUGH APRIL ANNUAL RYE MAY 1 THROUGH AUGUST 15 FOXTAIL MILLET AUGUST 16 THROUGH OCTOBER ANNUAL RYE NOVEMBER THROUGH FEBRUARY 15 WINTER RYE NOILS: 1. _IME A\L FERTILIZER NEEDS SHALL BE DETERMINED BY SOIL TESTS AN' APPLIED IN ACCORDANCE WITH VESCH STD. 3.32. 2. SEEDINGS TO BE MULCHED IMMEDIATELY UPON COMPLETION OF SEED APPLICATION, IN ACCORDANCE W/ VESCH STD 3.35. PERMANENT SEEDING SCHEDULE TOTAL LBS PER ACRE 128 LBS 2 LBS 20 LBS 150 LBS '�,� NO SCALE (STD. & SPEC. 3.32 OF VIRGINIA EROSION & SEDIMENT CONTROL HANDBOOK, 3RD ED.) TABLE 3.31-B ACCEPTABLE TEMPORARY SEEDING PLANT MATERIALS "QUICK REFERENCE FOR ALL REGIONS' Rate Planting Dates Specie Obs. acre Sept. 1 - Feb. 15 50/50 Mix of Annual Ryegrass (II multi-florum) & 50 - 100 Cereal (Winter) Rye (Secale cerea€e) Feb- 16 - Apr. 30 Annual Ryegrass 60 - 100 (L.olium multi-Ilorurn) May 1 - Aug 31 German Millet 50 (Setaria italica) Source: Va- DSWC DESCRIPTION OF EROSION & SEDIMENT COEN CONTROL MEASURES: ASURES: NTROL MEASURES: IT IS ANTICIPATED TO USE CONSTRUCTION ENTRANCES, DIVERSION DIKES, EXISTING SEDIMENT BASINS, AND SILT FENCES WILL BE INSTALLED TO CONTROL SURFACE DRAINAGE. TEMPORARY SEEDING WILL BE USED IMMEDIATELY FOLLOWING ALL LAND DISTURBANCE ACTIVITIES. TEMPORARY STOCKPILE AREAS WILL BE MAINTAINED FROM TOPSOIL THAT WILL BE STRIPPED FROM AREAS TO BE GRADED AND STORED FOR LATER SPREADING. STOCKPILE LOCATIONS SHALL BE ON SITE AND SHALL BE STABILIZED WITH A TEMPORARY VEGETATIVE COVER. PERMANENT SEEDING WILL BE PERFORMED FOR ALL AREAS WHICH WILL NO LONGER BE EXCAVATED AND WHERE CONSTRUCTION ACTIVITIES HAVE CEASED. PERMANENT SEEDING SHALL ALSO BE PERFORMED FOR ALL DENUDED AREAS WHICH WILL BE LEFT DORMANT FOR A YEAR OR MORE. SELECTION OF SEED MIXTURE WILL DEPEND ON THE TIME OF YEAR APPLIED. TEMPORARY SEEDING WILL BE PERFORMED FOR ALL DENUDED AREAS WHICH WILL BE LEFT DORMANT FOR MORE THAN SEVEN DAYS. THESE AREAS SHALL BE SEEDED WITH FAST GERMINA TING VEGETA TION IMMEDIA TEL Y FOLLOWING GRADING OF THOSE AREAS. SELECTION OF SEED MIXTURE WILL DEPEND ON THE TIME OF YEAR APPLIED. CONSTRUCTION ENTRANCE.• A STABILIZED PAVED CONSTRUCTION ENTRANCE WITH A WASH RACK LOCATED AT POINTS OF VEHICULAR INGRESS AND EGRESS ON A CONSTRUCTION SITE. TO REDUCE THE AMOUNT OF MUD TRANSPORTED ONTO PAVED PUBLIC ROADS BY MOTOR VEHICLES OR RUNOFF. CONSTRUCTION ENTRANCES SHALL BE INSTALLED AS SHOWN ON THE PLANS TO REDUCE THE AMOUNT SEDIMENT TRANSPORTED ONTO PUBLIC ROADWAYS. SILT FENCE. A TEMPORARY SEDIMENT BARRIER CONSISTING OF A SYNTHETIC FILTER FABRIC STRETCHED ACROSS AND ATTACHED TO SUPPORTING POSTS AND ENTRENCHED. TO INTERCEPT AND DETAIN SMALL AMOUNTS OF SEDIMENT FROM DISTURBED AREAS DURING CONSTRUCTION OPERATIONS IN ORDER TO PREVENT SEDIMENT FROM LEAVING THE SITE. TO DECREASE THE VELOCITY OF SHEET FLOWS AND LOW -TO -MODERATE LEVEL CHANNEL FLOWS. THE SILT FENCE BARRIERS SHALL BE INSTALLED DOWN SLOPE OF AREAS WITH MINIMAL GRADES TO FILTER SEDIMENT LADEN RUNOFF FROM SHEET FLOW AS INDICATED. THEY SHALL BE INSPECTED IMMEDIATELY AFTER EACH RAINFALL AND MAINTAINED IN ACCORDANCE WITH THE VIRGINIA EROSION & SEDIMENT CONTROL HANDBOOK (VESCH). PERMANENT STABILIZATION: THE ESTABLISHMENT OF PERENNIAL VEGETATIVE COVER ON DISTURBED AREAS BY PLANTING SEED. TO REDUCE EROSION AND DECREASE SEDIMENT YIELD FROM DISTURBED AREAS. TO PERMANENTLY STABILIZE DISTURBED AREAS IN A MANNER THAT IS ECONOMICAL, ADAPTABLE TO SITE CONDITIONS, AND ALLOWS SELECTION OF THE MOST APPROPRIATE PLANT MATERIALS. TO IMPROVE WILDLIFE HABITAT. TO ENHANCE NATURAL BEAUTY. UPON COMPLETION OF CONSTRUCTION ACTIVITIES, ALL AREAS WILL RECEIVE A PERMANENT VEGETATIVE COVER. TEMPORARY SEEDING: THE ESTABLISHMENT OF A TEMPORARY VEGETATIVE COVER ON DISTURBED AREAS BY SEEDING WITH APPROPRIATE RAPIDLY GROWING ANNUAL PLANTS. TO REDUCE EROSION AND SEDIMENTATION BY STABILIZING DISTURBED AREAS THAT WILL NOT BE BROUGHT TO FINAL GRADE FOR A PERIOD OF MORE THAN 30 DAYS. TO REDUCE DAMAGE FROM SEDIMENT AND RUNOFF TO DOWNSTREAM OR OFF -SITE AREAS, AND TO PROVIDE PROTECTION TO BARE SOILS EXPOSED DURING CONSTRUCTION UNTIL PERMANENT VEGETATION OR OTHER EROSION CONTROL MEASURES CAN BE ESTABLISHED. DUST CONTROL: REDUCING SURFACE AND AIR MOVEMENT OF DUST DURING LAND DISTURBING, DEMOLITION AND CONSTRUCTION ACTIVITIES. TO PREVENT SURFACE AND AIR MOVEMENT OF DUST FROM EXPOSED SOIL SURFACES AND REDUCE THE PRESENCE OF AIRBORNE SUBSTANCES WHICH MAY PRESENT HEALTH HAZARDS, TRAFFIC SAFETY PROBLEMS OR HARM ANIMAL OR PLANT LIFE. DUST CONTROL MEASURES SHALL BE EMPLOYED TO PREVENT SURFACE AND AIR MOVEMENT OF DUST DURING CONSTRUCTION. MEASURES EMPLOYED SHALL BE IN ACCORDANCE WITH THE VESCH. TEMPORARY DIVERSION DIKE: A RIDGE OF COMPACTED SOIL CONSTRUCTED AT THE TOP OR BASE OF A SLOPING DISTURBED AREA WHICH DIVERTS OFF -SITE RUNOFF AWAY FROM UNPROTECTED SLOPES AND TO A STABILIZED OUTLET OR TO DIVERT SEDIMENT -LADEN RUNOFF TO A SEDIMENT TRAPPING STRUCTURE. MAXIMUM EFFECTIVE LIVE IS 18 MONTHS. ROCK CHECK DAMS: SMALL, TEMPORARY STONE DAMS CONSTRUCTED ACROSS A DRAINAGE DITCH TO REDUCE THE VELOCITY OF CONCENTRATED FLOWS REDUCING EROSION OF THE SWALE OR DITCH. LIMITED TO USE IN SMALL OPEN CHANNELS WHICH DRAIN 10 ACRES OR LESS; SHOULD NOT BE USED IN LIVE STREAMS. STORM DRAIN INLET PROTECTION: THE INSTALLATION OF VARIOUS KINDS OF SEDIMENT TRAPPING MEASURES AROUND DROP INLETS OR CURB INLET STRUCTURES PRIOR TO PERMANENT STABILIZATION OF THE DISTURBED AREA; LIMITED TO DRAINAGE AREAS NOT EXCEEDING ONE ACRE, AND NOT INTENDED TO CONTROL LARGE, CONCENTRATED STORMWATER FLOWS. TEMPORARY SEDIMENT TRAP: A SMALL PONDING AREA, FORMED BY CONSTRUCTING AN EARTHEN EMBANKMENT WITH A STONE OUTLET ACROSS A DRAINAGE SWALE, TO DETAIN SEDIMENT -LADEN RUNOFF FROM SMALL DISTURBED AREAS FOR ENOUGH TIME TO ALLOW MOST TO THE SUSPENDED SOLIDS TO SETTLE OUT. MAXIMUM EFFECTIVE LIFE IS 18 MONTHS. TEMPORARY SEDIMENT BASIN: A TEMPORARY BARRIER OR DAM WITH CONTROLLED STORMWATER RELEASE STRUCTURES WHICH IS FORMED BY CONSTRUCTING AN EMBANKMENT OF COMPACTED SOIL ACROSS A DRAINAGEWAY. IT IS USED TO DETAIN SEDIMENT -LADEN RUNOFF FROM DRAINAGE AREAS 3 ACRES OR GREATER FOR ENOUGH TIME TO ALLOW MOST OF THE SUSPENDED SOLIDS TO SETTLE OUT. IT CAN BE CONSTRUCTED ONLY WHERE THERE IS SUFFICIENT SPACE AND APPROPRIATE TOPOGRAPHY MAXIMUM EFFECTIVE LIFE IS 18 MONTHS UNLESS DESIGNED AS A PERMANENT POND BY A QUALIFIED PROFESSIONAL. OUTLET PROTECTION. THE INSTALLATION OF RIPRAP CHANNEL SECTIONS AND/OR STILLING BASINS BELOW STORM DRAIN OUTLETS TO REDUCE EROSION AND UNDER -CUTTING FROM SCOURING AT OUTLETS AND TO REDUCE FLOW VEL OCI TIES BEFORE STORMWA TER ENTERS RECEIVING CHANNELS BELOW THESE OUTLETS. CULVERT INLET PROTECTION: A SEDIMENT FILTER LOCATED AT THE INLET TO STORM SEWER CULVERTS WHICH PREVENTS SEDIMENT FROM ENTERING, ACCUMULATING IN AND BEING TRANSFERRED BY THE CULVERT. IT ALSO PROVIDES EROSION CONTROL AT CULVERTS DURING THE PHASE OF A PROJECT WHERE ELEVATIONS AND DRAINAGE PATTERNS ARE CHANGING, CAUSING ORIGINAL CONTROL MEASURES TO BE INEFFECTIVE. SAFETY FENCE: A PROTECTIVE BARRIER INSTALLED TO PROHIBIT UNDESIRABLE USE OF AN EROSION CONTROL MEASURE. PERMANENT STABILIZA TION: PERMANENT SEEDING WILL BE APPLIED TO ALL DISTURBED AREAS AS PER THE PERMANENT STABILIZATION OF THIS EROSION & SEDIMENT CONTROL NARRATIVE AFTER CONSTRUCTION IS COMPLETED, ALL DISTURBED AREAS OF THE SITE WILL BE LIMED, FERTILIZED, AND SEEDED AS PER CURRENT VDOT STANDARDS. THIS SHALL CONSIST OF THE FOLLOWING: TOP SOIL - 2 " DEP TH LIME - 2 TONS/ACRE FERTILIZER - 600 LBS/ACRE OF 15-30-15 SEED - ERNST 5311 CONSERVATION SEED MIX - ERNMX-114 (45 LBS/ACRE PENNLAWN CREEPING RED FESCUE, 37.5 LBS/ACRE ARGILS KENTUCKY BLUEGRASS, 37.5 LBS/ACRE PARK KENTUCKY BLUEGRASS, 15 LBS/ACRE ANNUAL RYEGRASS & 15 LBS/ACRE PLEASURE PERENNIAL AFTER THESE AREAS ARE STABILIZED THEY WILL BE MOWED AND MAINTAINED ON A REGULAR BASIS. MAINTENANCE IN GENERAL, ALL EROSION AND SEDIMENT CONTROL MEASURES WILL BE CHECKED DAILY AND AFTER EACH SIGNIFICANT RAINFALL. SPECIFIC ATTENTION WILL BE GIVEN TO THE FOLLOWING ITEMS: A. SEDIMENT BASINS AND/OR TRAPS WILL BE CLEANED AND MAINTAINED IN ACCORDANCE WITH THE VIRGINIA EROSION & SEDIMENT CONTROL HANDBOOK. B. ALL GRAVEL OUTLETS WILL BE CHECKED REGULARLY FOR SEDIMENT BUILDUP THAT WILL PREVENT PROPER DRAINAGE. IF THE GRAVEL IS CLOGGED BY SEDIMENT, THE GRAVEL WILL BE REMOVED AND CLEANED, OR IT WILL BE REPLACED. C. ALL SlL T FENCE BARRIERS 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 REACHED HALF WAY TO THE TOP OF THE BARRIER. D. ALL SEEDED AREAS WILL BE CHECKED REGULARLY TO SEE THAT A GOOD STAND IS MAINTAINED. AREAS SHOULD BE FERTILIZED AND RESEEDED AS NEEDED. EROSION CONTROL NOTES & NARRATIVE "-, 016PURPOSE �� THE PURPOSE OF THIS LAND DISTURBING ACTIVITY IS TO CREATE THE MARTHA JEFFERSON HOSPITAL APARTMENTS PROJECT. � I THE TOTAL AREA TO BE DISTURBED WITH THIS PLAN IS 17.17 ACRES. EXISTING SITE CONDITIONS. SCOTT R. LLINS'� THIS SITE IS CURRENTLY A MIXTURE OF WOODS AND GRASS AND DRAINS TO EXISTING WATERWAYS LOCATED TO THE EAST, WEST, AND SOUTH. AN EXISTING GRAVEL ROAD EXISTS ON -SITE, EXISTING PRESERVED STEEP SLOPES EXIST ON -SITE. �_) No. 35791 ,� ADJACENT AREAS: THIS SITE IS BORDERED TO THE NORTH BY PETER JEFFERSON PARKWAY. TO THE SOUTH EXISTS THE RIVANNA RIVER. AN 1;P 6I1/20 w� EXISTING COMMERCIAL PROPERTY EXISTS TO THE WEST. A CURRENTLY VACANT MIXED -USE COMMERCIAL LOT EXISTS TO THE OEAST � OFFSITE LAND DISTURBANCE. • �S�IONAL "6 NO CONSTRUCTION ACTIVITIES ARE PROPOSED OUTSIDE OF THE LIMITS OF DISTURBANCE. ALL OFFSITE WORK SHALL BE CONFINED TO PUBLIC RIGHT-OF-WAY AND EASEMENTS. CRITICAL AREAS: CARE SHALL BE TAKEN TO PREVENT CONSTRUCTION RUNOFF FROM ENTERING THE EXIS77NG PRESERVED STEEP SLOPES, RIVANNA RIVER AND ADJACENT PROPERTIES. SOILS: A SOILS MAP IS INCORPORATED INTO THE PHASE I EROSION CONTROL PLAN WITH SOILS DATA INCLUDED WITH THIS NARRATIVE. SEQUENCE OF CONSTRUCTION: 1. N077FY ALBEMARLE COUNTY TO SCHEDULE A PRE- CONS TRUC T70N MEETING AS REQUIRED. 2. NO EROSION CONTROL MEASURES MAY BE REMOVED DURING THE CONSTRUCTION PROCESS WITHOUT THE APPROVAL FROM THE INSPECTOR ON THE PROJECT. J. INSTALL THE PAVED CONSTRUCTION ENTRANCE WITH WASH AREA AS SHOWN ON THE PLANS. CONSTRUC77ON ENTRANCES TO BE INSTALLED WHERE CONSTRUCTION VEHICLE 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 TRANSPORTING TO A SEDIMENT CONTROL DISPOSAL AREA. STREET WASHING SHALL BE ALLOWED ONLY AFTER SEDIMENT IS REMOVED IN THIS MANNER 4. INSTALL THE INITIAL CONSTRUCTION MEASURES AS SHOWN ON 7HE PHASE I EROSION CONTROL SHEET. THIS INCLUDES (1) CONSTRUCTION ENTRANCE, (2) SEDIMENT BASINS, (2) SEDIMENT TRAPS, CONSTRUCTION ROAD STABILIZATION, SILT FENCE, AND DIVERSION DIKES MEASURES INTENDED TO TRAP SEDIMENT SHALL BE CONSTRUCTED AS A FIRST STEP WITH ANY LAND DISTURBANCE AC77WTY AND SHALL BE MADE FUNCTIONAL BEFORE UPSLOPE LAND DISTURBANCE TAKES PLACE. 6. ONCE THE PERIMETER EROSION CONTROL MEASURES HAVE BEEN INSTALLED AS SHOWN ON THE PHASE l EROSION CONTROL U) PHASE PLAN, CONTRACTOR SHALL INSTALL ANY REMAINING ESC PHASE I CONSTRUCTION MEASURES AS SHOWN ON THE z EROSION CONTROL SHEET, INCLUSIVE OR TEMPORARY SEEDING & DUST CONTROL AS NEEDED. 0 Q 7. PERMANENT OR TEMPORARY SOIL STABILIZATION SHALL BE APPLIED TO DENUDED AREAS WITHIN SEVEN DAYS AFTER FINAL GRADE IS REACHED ON ANY POR77ON OF 7HE SITE. TEMPORARY SOIL STABILIZA77ON SHALL BE APPLIED WITHIN a SEVEN DAYS TO DENUDED AREAS THAT MAY NOT BE AT FINAL GRADE BUT WILL REMAIN DORMANT (UNDISTURBED) FOR O C)� m LONGER THAN 30 DAYS. PERMANENT STABILIZA77ON SHALL BE APPLIED TO AREAS THAT ARE TO BE LEFT DORMANT FOR M Z5 MORE 7HAN ONE YEAR. w 8. AFTER INSTALLATION OF ALL OF 774E PHASE l ESC MEASURES, 774E CONTRACTOR CAN CLEAR THE SITE. (� 0 _Jr/ 9. ONCE ESC PHASE l IS COMPLETE THE CONTRACTOR CAN PROCEED TO ESC PHASE ll. THE CONTRACTOR SHALL ENSURE THE z Q PERIMETER DIVERSIONS MAINTAIN POS177VE GRADES AT ALL TIMES & DISCHARGE INTO THEIR RESPEC77VE EROSION & M O SEDIMENT CONTROL TRAPPING DEVICES �n z 10. CONTRACTOR SHALL INSTALL THE ESC PHASE // CONSTRUCTION MEASURES AS SHOWN ON THE EROSION CONTROL SHEET, '-' INCLUSIVE OR TEMPORARY SEEDING & DUST CONTROL AS NEEDED. PERIMETER MEASURES INTENDED TO 7RAP SEDIMENT w SHALL BE CONSTRUCTED AS A FIRST STEP W1174 ANY LAND DISTURBANCE ACTIVITY AND SHALL BE MADE FUNCTIONAL BEFORE UPSLOPE LAND DISTURBANCE TAKES PLACE. 11. DURING THIS ESC PHASE ll, ROUGH GRADING OPERA77ONS CAN BEGIN. Ce 12. ONCE 774E S17F HAS BEEN ROUGH GRADED TO THE POINT WHERE SEDIMENT TRAP #2 CAN NO LONGER REMAIN, THE CONTRACTOR CAN FILL THIS TRAP. THE REMOVAL OF SEDIMENT TRAP #2 SHALL NOT OCCUR PRIOR TO THE APPROVAL OF THE COUNTY INSPECTOR. DEWATERING OF SEDIMENT TRAP #2 SHALL BE COMPLETED IN ACCORDANCE WITH MINIMUM VESCH SPECIFICATIONS. 13. PERMANENT OR TEMPORARY SOIL STABILIZATION SHALL BE APPLIED TO DENUDED AREAS WITHIN SEVEN DAYS AFTER FINAL GRADE IS REACHED ON ANY PORTION OF THE SITE. TEMPORARY SOIL STABILIZATION SHALL BE APPLIED W774IN SEVEN DAYS TO DENUDED AREAS THAT MAY NOT BE AT FINAL GRADE BUT WILL 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. 10. THE CONTRACTOR SHALL THEN PROCEED TO ESC PHASE Ill. CONTRACTOR SHALL INSTALL THE ESC PHASE 111 CONS7RUC770N MEASURES AS SHOWN ON THE EROSION CONTROL SHEET, INCLUSIVE OR TEMPORARY SEEDING & DUST CONTROL AS NEEDED. PERIMETER MEASURES INTENDED TO TRAP SEDIMENT SHALL BE CONSTRUCTED AS A FIRST STEP WITH ANY LAND DISTURBANCE ACTIVITY AND SHALL BE MADE FUNC7ONAL BEFORE UPSLOPE LAND DISTURBANCE TAKES PLACE. 11. THE CONTRACTOR SHALL COMPLETE THE ROUGH GRADING OF THE SITE IN ESC PHASE Ill. 12. FOLLOWING THIS THE CONTRACTOR SHALL FINE GRADE THE SITE AND INSTALL THE UTILITIES, CURB & GUTTER, SIDEWALK, BUILDING & PARKING PADS AND REMAINING INFRASTRUCTURE. 13. INLET PR07ECT70N SHALL BE INSTALLED ON ALL STORM SEWER INLETS AND YARD DRAINS IMMEDIATELY FOLLOWING THEIR INSTALLATIONS. ANY DRAINAGE SYSTEM FOUND TO BE CLOGGED OR CONTAINING SEDIMENT DURING CONSTRUCTION SHALL BE CLEANED PRIOR TO THE COMPLETION OF THE PROJECT. 14. PERMANENT OR TEMPORARY SOIL STABILIZATION SHALL BE APPLIED TO DENUDED AREAS WITHIN SEVEN DAYS AFTER FINAL GRADE lS REACHED ON ANY PORTION OF 77.1E SITE TEMPORARY SOIL STABILIZATION SHALL BE APPLIED WITHIN SEVEN DAYS TO DENUDED AREAS THAT MAY NOT BE AT FINAL GRADE BUT WILL REMAIN DORMANT (UNDISTURBED) FOR l.0 oN o LONGER THAN 30 DAYS. PERMANENT STABILIZA77ON SHALL BE APPLIED TO AREAS THAT ARE TO BE LEFT DORMANT FOR Q t i _4 MORE THAN ONE YEAR. 0 � 15. THE PERIMETER DIVERSIONS SEDIMENT TRAP #1 SEDIMENT BASIN #1 AND SEDIMENT BASIN #2 SHALL REMAIN FUNCTIONAL "T AS LONG AS POSSIBLE. THESE SEDIMENT 7RAPPING DEVICES SHALL NOT BE REMOVED PRIOR TO THE APPROVAL OF THE COUNTY INSPECTOR. 16. AFTER THE SITE IS FULLY STABILIZED, AND THE PROJECT's CONSTRUCTION IS NEAR COMPLETION, THE CONTRACTOR SHALL INSTALL THE BIORE7ENT70N BASIN. FOLLOWING THIS, SEDIMENT TRAP #1 CAN BE REMOVED, SEDIMENT BASIN #1 CAN BE CONVERTED TO A PERMANENT SWM FACILITY, SEDIMENT BASIN #2 CAN BE CONVERTED TO A PERMANENT SWM FACILITY AND THESE FACILITIES' PERIMETER DIVERSIONS CAN BE REMOVED. DEWATERING OF THESE FACILITIES SHALL BE COMPLETED L9 IN ACCORDANCE WITH MINIMUM VESCH SPECIFICATIONS. 17. NO EROSION CONTROL MEASURES MAY BE REMOVED DURING THE CONSTRUCTION PROCESS WITHOUT THE APPROVAL OF THE INSPECTOR ON THE PROJECT. 18. MAINTAIN ALL EROSION CON7ROL MEASURES AS SPECIFIED IN THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, REMOVING ONLY WHEN APPROVED BY THE LOCAL PROGRAM ADMINISTRATOR IN ACCORDANCE WITH THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK. 19. ALL TEMPORARY EROSION AND SEDIMENT CON77?OL MEASURES SHALL BE REMOVED WITHIN 30 DAYS AFTER FINAL SITE STABILIZATION OR AFTER THE TEMPORARY MEASURES ARE NO LONGER NEEDED, UNLESS 07HERKISE 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. IIIIIIIIIIIIIIIIIII 20.ONCE THE SITE IS STABILIZED AND THE INSPECTOR HAS GIVEN APPROVAL, THE CONTRACTOR CAN REMOVE THE REMAINING EROSION CONTROL MEASURES NO ITEM SHALL BE REMOVED UNLESS THE UPSTREAM AREAS ARE STABILIZED AND THE INSPECTOR GIVES PERMISSION. SOIL DESCRIPTION 72C3 - RABUN CLAY - SEVERELY ERODED, 77 TO 157 SLOPES. THESE DEEP, WELL DRAINED SOILS ARE FOUND ON GENTLY SLOPING TO STEEP RIDGES AND MOUNTAIN SLOPES. MODERATE TO RAPID RUNOFF, WITH MODERATE PERMEABILITY. 72D3 - RABUN CLAY - SEVERELY ERODED, 159 TO 259 SLOPES. THESE DEEP, WELL DRAINED SOILS ARE FOUND ON GENTLY SLOPING TO STEEP RIDGES AND MOUNTAIN SLOPES. MODERATE TO RAPID RUNOFF, WITH MODERATE PERMEABILITY. 73D - RABUN VERY STONY CLAY LOAM - SEVERELY ERODED, 157 TO 257 SLOPES. THESE DEEP, WELL DRAINED SOILS ARE FOUND ON GENTLY SLOPING TO STEEP RIDGES AND MOUNTAIN SLOPES. MODERATE TO RAPID RUNOFF, WITH MODERATE PERMEABILITY. 73E - RABUN VERY STONY CLAY LOAM - SEVERELY ERODED, 25Z TO 45Z SLOPES. THESE DEEP, WELL DRAINED SOILS ARE FOUND ON GENTLY SLOPING TO STEEP RIDGES AND MOUNTAIN SLOPES. MODERATE TO RAPID RUNOFF, WITH MODERATE PERMEABILITY. W - WA TER TEMPORARY SEEDING: ALL DENUDED AREAS WHICH WILL BE LEFT DORMANT FOR EXTENDED PERIODS OF TIME SHALL BE SEEDED WITH FAST GERMINA TING TEMPORARY VEGETA TION IMMEDIA TEL Y FOLLOWING GRADING. SELECTION OF THE SEED MIXTURE WILL DEPEND ON THE TIME OF YEAR AND WILL BE APPLIED TO DISTURBED ARES THAT WILL NOT BE BROUGHT TO FINAL GRADE WITHIN 30 DA YS. PLANTS SHOULD BE SELECTED APPROPRIATE TO THE SEASON AND SITE CONDITIONS FROM TABLES 3.31B AND 3.31C. NOTE THAT TABLE 3.31B PRESENTS PLANTS WHICH CAN BE USED WITHOUT EXTENSIVE EVALUATION OF SITE CONDITIONS; TABLE 3. 31 C PRESENTS MORE IN-DEPTH INFORMATION ON THE PLANT MATERIALS. TO CONTROL EROSION ON BARE SOIL SURFACES, PLANTS MUST BE ABLE TO GERMINATE AND GROW. SEEDBED PREPARATION IS ESSENTIAL. AN EVALUATION SHOULD BE CONDUCTED TO DETERMINE IF LIME IS NECESSARY FOR TEMPORARY SEEDING. TABLE 3.31A MAY BE USED TO DETERMINE THE ACTUAL NEED ALONG WITH SUGGESTED APPLICATION RATES: FERTILIZER SHALL BE APPLIED AS 600 LBS/ACRE OF 10-20-10 (14 LBS/1, 000 SQ. FT.) OR EQUIVALENT NUTRIENTS. LIME AND FERTILIZER SHALL BE INCORPORATED INTO THE TOP 2 TO 4 INCHES OF THE SOIL IF POSSIBLE. IF THE AREA HAS BEEN RECENTLY LOOSENED OR DISTURBED, NO FURTHER ROUGHENING IS REQUIRED. WHEN THE AREA IS COMPACTED, CRUSTED, OR HARDENED, THE SOIL SHALL BE LOOSENED BY DISCING, RAKING, HARROWING, OR OTHER ACCEPTABLE MEANS. TRACKING WITH BULLDOZER CLEATS IS MOST EFFECTIVE ON SANDY SOILS. THIS PRACTICE OFTEN CAUSES UNDUE COMPACTION OF THE SOIL SURFACE, ESPECIALLY IN CLAYEY SOILS, AND DOES NOT AlD PLANT GROWTH AS EFFECTIVELY AS OTHER METHODS OF SURFACE ROUGHENING. SEED SHALL BE EVENLY APPLIED WITH A BROADCAST SEEDER, DRILL, CUL TIPACKER SEEDER OR HYDROSEEDER. SMALL GRAINS SHALL BE PLANTED NO MORE THAN 1� INCHES DEEP. SMALL SEEDS, SUCH AS KENTUCKY BLUEGRASS, SHOULD BE PLANTED NO MORE THAN 4 INCH DEEP. OTHER GRASSES AND LEGUMES SHOULD BE PLANTED FROM 4 INCH TO � DEEP. SEEDINGS MADE IN FALL FOR WINTER COVER AND DURING HOT AND DRY SUMMER MONTHS SHALL BE MULCHED ACCORDING TO MULCHING, STD. & SPEC. 3.35, EXCEPT THAT HYDROMULCHES (FIBER MULCH) WILL NOT BE CONSIDERED ADEQUATE. STRAW MULCH SHOULD BE USED DURING THESE PERIODS. AREAS WHICH FAIL TO ESTABLISH VEGETATIVE COVER ADEQUATE TO PREVENT RILL EROSION WILL BE RE -SEEDED AS SOON AS SUCH AREAS ARE IDENTIFIED. STORM WA TER RUN-OFF CONSIDERATIONS: STORMWATER MANAGEMENT. THE STORMWATER RUNOFF FROM THIS PROJECT DRAINS TEMPORARILY TO TWO PROPOSED SEDIMENT BASINS & 2 SEDIMENT TRAPS. THE TWO SEDIMENT BASINS WILL BE CONVERTED TO PERMANENT STORMWATER MANAGEMENT FACILITIES AND THE TWO SEDIMENT TRAPS WILL BE REMOVED AFTER THE DEVELOPMENT OF THE MARTHA JEFFERSON HOSPITAL PRESIDIO APARTMENTS DEVELOPMENT. SEE SHEETS 6-9 FOR ADDITIONAL DETAILS PERTAINING TO THE STORMWATER QUALITY AND QUANTITY COMPLIANCE. LC W W Z W Ul Z rl CY, z LU CY) 0 M z N LCU ,'I-G M Q 'T z N Q O O J N W N 10- > Q > U) Q > L d I 0. J Q J V) z u z J G p� ~p � z J � a- U Q Q (-) O z 1 1-1 w Y 0 1--1 I --I W (J) 0 F____ W W V) U) a 016 wQ z W I—1-­1 O U) 0 U) O oC = LU w z O Q (D W O LL. O L.L n N Q I— I- 0+ LU w w a- U) JOB NO. 172131 SCALE AS NOTED SHEET NO. 3 Project MJH Apartments - Stockpile Area Plan Sheet No. Designer AM L, PE Sheet 1 of 2 APPROVED Culvert #1 Rev. Date Date 4/3/18 AHW Controls STATION: HYDROLOGIC& DATA 100 yr. Flood plain elev. Design AHW depth elev. Structures elev. freq. - TWelev. Culvert #1: DA=2.07 ac., Cw=0.45, Tc=9.5 min., 2-year Q=3.96 cfs, 10-year Q=5.31 cfs = Shoulder = elev. 414.00 = CL elev. 414.00 DISCHARGES USED RISKASSESSMENT ADT Skew ° Cover n Q 2 = 3.96 CFS Detours Available Length Q 10 = 5.31 CFS Overtopping Stage Q = CFS Flood Plain Management Inv. El. 412.00 So= 4.00% Inv. El. 410.00 Q = CFS Criteria and Significant Impact Orig. Gr. Elev. L= Orig. Gr. Elev. Q = CFS HEADWATER COMPUTATIONS CONT. OUTLET CULVERT TYPE & SIZE Q Q/B HW. VELOCITY End COMMENTS INLET CONT. OUTLET CONTROL Treat HW/D HW Ke do (dc+D)l2 ho H LSo HW C.M. Smooth ELEV. Proposed 18" CM P Culvert (2 yr) 3.96 3.96 0.80 1.2 0.5 0.6 0.93 0.93 0.2 2.0 -0.9 1.2 5.87 ES-1 VDOT STD. EC-1 Class Al Outlet Protection Proposed 18" CM P Culvert (10 yr) 5.31 5.31 0.95 1.4 0.5 0.8 1.03 1.03 0.6 2.0 -0.4 1.4 6.35 ' I III 1 \ e amenrap MATCHLINE, SEE SHEET 4B FOR ESC esign I I I I D� drainage area (acres) (<3) 1.23 C5 MEASURES FOR SANITARY SEWER & I trap volumes: , �ARIA�LE• SIDEWALK IMPROVEMENTS I{3 I I I I I I I I Ex.E"°' / / elevation (ft) area (so volun-e(cf) volume(cy) �- CREST OF STONE WEIR 408.00 394.0 0 0.0 �� 11 VARIABLE• \ \ \ \ \ 1 1 1 \ I \ 410.00 726.0 1,103 40.9 _ ,.0 \\ VA\ \\ 412.00 1141.0 2,955 109.4 414.00 2253.0 6,286 232.8 DRY STORAGE ry VARIABLE WET STORAGE 7- (EXCAVATED) . �. I FILTER CLOTH ORIGINAL cs\ 6' \\� \ wet storage: 1 ELEV. / ,c� \ \ \ \ -SEE PLATE 3.13-1 COARSE AGGREGATE ' CLASS I RIPRAP w/ WIRE �� wet storage required (cy) (67*DA) 82.4 SUPPORT SF I � I I I l/ / l l (\�\\�\ \�\ \\\\ / / \ \\\\ \ \ bottom of stone weir (ft) 411.20 w/ WIRE I ♦ / / / / �\ \\ \V A VA wet storage provided at this elevation (cy) 82.4 I I / �� \ \ ■ slope of wet storage sides 1:1 SF SUPPORT 1 I r Is �■I ■\��C\ weir length (ft) (6ADA) 7.4 dry storage: bottom of trap elevation (ft) 408 dry storage required (cy) (67*DA) 82.4 bottom trap dimensions: 71'xT crest of stone weir 413.00 top of dam elevation (ft) 414.00 III I I EXISTING TREELINE (TYP.) I I I � � � � \ � _ _ dry storage provided at this elevation (cy) 88.7 top width of dam (ft) 2 ( ) I I \ 3 \\ \\ slope of dry storage sides 2:1 top trap dimensions 115x23 / PROPOSED SAFETY I I \ X . / / / - I \ \ \ \\\ \ \ I 430.9 434.5 / / l l FENCE AROUND x \ \ I \ \ Q -- / ,, � / x416.B / �/ / / / / / / SEDIMENT TRAP \ I { \ V A\ V A \ A I x Q x 487.3 \ \ x 433.4 �/� / / / �� / \ \ \ �� l \ I � � 4B4. 7 gr SEE THIS \ Q DESC PH PROPERTY LINE 1 \ \ \\ \ x SHEET �A \ x DESIGN I ST #1 . DETAILS / // I DA= 1.23 ac. I 1 \ x (DESIGN DA - 1.23 ac.) 5.z I \ V A W / 0489.0 / w/ WIRE / / \ x SUPPORT SF / / / / / / / � � / / �� \\\ 484.8 ♦♦ AMENDED LIMITS OF 495.1 - - - / - - \\� 489.z DISTURBANCE = 17.17ac. x - - - - � 0a '�0 // y j �/ % % �/ // / / / / / I I I I I ♦ / / / LOCATION OF CONTRACTOR PARKING & ♦♦V1♦470.9 A \ \\VA / x�p w // III III II II I I I I X I STAGING TAGINGI AREA ■WITH �■P■O,... �RT\A POTTIES ♦\� \ \9.2x.D\l DUMPSTER, AND FUELINGTANK�, 471.5 APPROVED x WASH RACK/ / /�/ I� I �1I � I I ♦_ 7 12'x70'MIN. Q x 4s�o°.8 7 x 492.8 4/94.8CE x / / -_ ---_ - /�\---- --_\�P TM' 78 2 �Y I � � �State�Farm tu/al FLOW DIRECTION_ sueA t �aeo ARROW (TYP.) /q-D. 7 _ ---_ D.B. 669 p. �5, pi5tla�tLIMITS OF PROPOSED ------ - - - /- - TREE CLEARING (TYP.) I I I I ♦I 1 \ A I / I //✓i/ / / //- �// j ///�/ / / / / - - -- I 45\4. II °I - _470 jO // EXISTING PRESERVED /DD STEEP SLOPES (TYP.) -� ----- _--- _-- - / _ ♦ / / / / //- TMP: 07800-00-00-020J0 _ _350, CONTRACTOR TO ENSURE POSITIVE -3J� _ TP % / /) ! %♦ I DRAINAGE DIVIDE (TYP.) - �� \ ° ��6 OWNER. JDM II SF NATIONAL LLC _ - - DRAINAGE ALONG DIVERSION BERMS /// // I s \ �/ / / / / -- - - - / ' APPROVED ESC PHI - C/O STATE FARM MUTUAL � 100 Z � � / / ♦♦ / � � ♦ I � � \ � � \ V ♦♦ SB #1 DA= 8 AUTOMOBILE \ // ♦ .55 �/ ZONING: COMMERCIAL OFFICE / / = �/ I I A V _ CRS - (APPROVED BASIN DA / / / / / (�� �• I I co SIZED FOR 12.00 ac.)ACREAGE: 19.88 AC DD DB/PG: 4475/728 / - - - - Ix 458.6 xIlk 459.9 Sol x o- _---_ 8 4W Ivy y • v v ° I / /// I l//l / // //i/ // / • /, v -♦- -O - ♦_ PROPOSED SAFETY FENCE / ♦ / / ° \ / / / // / / / / / /_ / / / / //� / / / / - - - - - - - 00 AROUND SEDIMENT BASIN♦/ / / °, x I ♦\ / CIP / ° / / x 464.0 / ♦ / / APPROVED ESC PH I �0z.4 ♦ / I / / // owl / SB #2 DA=1.78 ac. / i ■♦ ° ° / / / /� / / (AMENDED DESIGN j°• ° �, I / / % / I l I I / l l l / / / / / / \ / ® _ / 406.4 WD / / / 464.4 + / - / / I DA=6.04 ac.) :�i / / / x \ w/ WIRE SF / I /, // SUPPORT / I APPROVED TEMPORARY CULVERT #1 I ► / / III o/ i SOIL DESCRIPTION (TYP.) CRS I� / � DRAINAGE AREA-2.07ACRES I / � , / �T�C3 I ��\ �� i I / I - 18" CMP, 50.00' @ 4.00%, w/ (2) ES-1 I / " '/ / / y �.� �/ / 463.E /• �_ ° 402.8x INV IN=412.00, INV OUT=410.00 / x x x I I / / / / // / / / / / CD \464.4/oIII�I I v / TMP: �� '07800-00_0 -020M3 / / APPROVED CLASS Al OUTLET/ I - I �� \ PROTECTION w/ GEOTEXTILE FILTER I / OWNER: MARTHA JEFFERSON HOSPITAL / I / J I ♦ B I ° / l W - \ ° FABRIC UNDERLAYMENT I I / ZONING: PLANNED DEVELOPMENT MIXED x EXISTING GRAVEL DRIVE TO I I I I ( COMMERCIAL 463.8 �- / , , � I / / ♦ / j / � / � \ � ° (L=8 JW1=4.5', W2=9.5', D=1.5' MIN. \g�0 I I I ( � -` � / � I I � r �3 / // / / / / / / - / • EXISTING TREELINE (TYP.) BE RE-ROUTED AS SHOWN 0.7 \ ACRLAGE: 26.98 AC v� _ v I //i SEE SHEET 8 FOR RIPRAP OP I / / / / / / / % / NV \ \ / /� � I � I I / \ OUTLET PROTECTION / \ DD 463.z / / / / I I j DESIGN & DETAILS RR ° / / / TS ♦ x-\ \\ ° \ \ \ �\ \ \\ \\ \ \/ / / L LINE (TYP.) / / \� \ / / / - 399. o EXISTING - /, ° / o ° / / / - \ 0 V 1� \ \\ \ \ \ \\ \\ \ \ \ � / /� / / / / / • TREELINE ° (TYP.) / \ / PS APPROVED ESC PHI \ V A\\ VAA \ / / / - % I I I / / / / % •/ / I I / / \ / / 6 s ST #2 DA=1.26 ac. \ x \ \ \ �� \ \ / �\ - _- = I I / / l l • / / l I I / I / I % ./ / / / A ♦ (APPROVED DESIGN o� I / / CONNECT TO EXISTING DC k % \ APPROVED 48 RCP STANDPIPE \ _\ \_ _ DA=1.26 ac.} TO SERVE AS RISER STRUCTUREGRAVEL DRIVE APPROVED STOCKPILE AREA PROPOSED 48" RCP STANDPIPE \ \ \ - =\�\ \\\\// /� / __ CONTRACTOR TO ENSURE POSITIVE '- TO SERVE AS RISER STRUCTURE I / � \ - � 100 STREAM I ♦ / �� ♦ APPROVED BAFFLE �� ` / I 1 \ BUFFER CONTRACTOR SHALL INSTALL THE PERMANENT DRY / /APPROVED SAFETY FENCE / \ /j / - DRAINAGE ALONG DIVERSION BERM / V \ I1 I I DETENTION CELL EMBANKMENT, RISER FOUNDATIONI W AROUND SEDIMENT TRAP / x - - APPROVED SAFETY FENCE BARREL, OUTLET PROTECTION & SPILLWAY AT THE TIMEOF AROUND SEDIMENT BASIN THE TEMPORARY SEDIMENT BASIN's CONSTRUCTION. \� - I ♦ \\\\ �// / I I III I I / / / _-- \ \ • \ I LOW -FLOW ORIFICE SHALL BE PERMANENTLY BLOCKED DD ♦ / e__7 \ \ O WATERTIGHT DURING ESC PHASES. CONVERSION OF BASIN ♦ ♦ / / - - \\ \\ _ \ \ \// ti I I I / \ SHALL ONLY OCCUR AFTER ESC INSPECTOR APPROVAL. DC I\ 1 ♦ V A \ SEE SHEET 8 FOR�DDITIONAL DESIGN DETAILS. I \I TP I \ ♦ \ \ ♦ ° \ \ - - A \\VAA _ / / � \ / ♦ I I I / / / PROPOSED BAFFLE �/ J v �� �\, \\ \ V A \ A'♦ v •vyx - v a v v 7TI)/ I I qI III II I / I \ \ \ I I \ \ \\ \\ \ \\ AA\ V\ ♦♦ FLOODPLAIN (TYP.) 1- \ \ - \ I 2 IAPPROVED STOCKPILE AREA DRAINAGE DIVIDE (TYP TO BE ENCOMPASSED BY I I ♦�� ♦N /� J \ ♦1♦ \ \\� - - - - - - - \\ / / / / I I I I I I I / / SILT FENCE AT ALL TIMES - - �� �■ ■� \ ♦ V \ _ _ _ - V A \ - - - / / I I I / 314.E x CONTRACTOR TO ENSURE POSITIVE ` DD (won \ \ ♦ - / / I L4 t- \ \ OO \ \ \ \ \\ DRAINAGE ALONG DIVERSION BERMS - - - '� ♦ - - �♦ / \ - - / 352. 7B \ \ \ \ \ w/ WIRE �F\♦\ M�/8 20M1 � \ \ \ J ♦ \ _- �-�y / nt SUPPORT rre aeveop��39LD.kZ6U 2525`0 plat p 72 00. / � -y ��- -y- \ \ ■� - y----_�/�//// / // //\ // / / V A \ \ \ gA 167 la \T\ LIMITS OPROPOSED TREE CLEARING EXISTING GRAVEL ROAD \ \ \ \ \ \ w/WIRE / C OP P - / - 50- -D' 25 50 00 200 LIMITS OF DAM INUNDATION ZONE // / //� 307.5 �x \\ \ \ VA ��VA� \// / -370 - APPROVED 30" - \ \ �� \\ \ \ _ - _ APPROVED VDOT CL. I RIPRAP WITH - �- _ x 308.4 \ \ \ \ \ _ - ��\ �� �\ �- - RCP BARREL - \ \\ \ CONNECT TO EXISTING FILTER FABRIC UNDERLAYMENT. SEE - - - _ APPROVED 7 FOR DETAILS. LIMITS OF DAM INUNDATION ZONE (TYP.) / N/FE - V o \� �� \ VA GRAVEL DRIVE x x 9S C 0 T T R. LLINS U No. 35791 � 6/1/20 1���.,SIIOIVAL �� E�O��� 0 fV Lo N Ln 0 W Q V) (n Z z O I- LU OCl- � c U w m 5 O � cn J z Q H O U z 0� LV w LU U) z 3 0 wLU ti 00 Cl? CY) N 0 W0) N W Q Z L1J J_ > U) LU LU W O 0 N ,--1 LU 0 LU z Q a- z J (n � J O z � LU z O < z Q LU O 0 0 LU LU 016 � z Q 0 I -I U) 0 w z O LU LL LU LU Q w W a (10 JOB NO. 172131 SCALE lit= 50' SHEET NO. 4 MA TCHLINE, SEE�SHEET 4B FOR ESC MEASURES FOR SANITARY SEWER & l I SIDEWALK IMPR VEMENTS \ - - / /, ,, ,,, ,,�/ , , , l , 1 , / / // Ds�� ll / E$I �PH�l 1 , i ° /c, 0.0 � (q �N� °r E I �w OOF uwc � ,I In Q ; '! �SCOTT R. LLINS U No. 35791 � 6/1/20 0���sICNAL \_j U // /i/ // �� / / I U TI 1 //�1/ v v� iF �YP�OOT�I \ ///�\VA v EXISTING i REELINE (TYP.) \ PROPOSED SAFETY - • �� \ \ o / \\ \ I \ n FENCE AROUND c M ` I 1 � \\\ \ \\ \ \ - I � \ o Q w / _ / - (SEDIMENT TRAP ( ■ \\ \VA / Z Lu //�/ / / // \ I 9E� T ISIS�1 \ ■ •� \ \ \3 \\ \ /. % 1 O o j j j / / / / / / HEElT F�R, \ \ VA\ V A rml Lf) U - _ _ - - _ - - i / / /� - �DF�SI N' \ - Q w cn — --- _ /// /////// � ��\v v oJZ �E AI S � � x,■ � I I � \ \ \ / z Q � U) o _ _ --- /� / / //////// / / ■ I I / I I I vvv vvv w / / / z w/ WIRE S�� A VA \\\ / // / w a w SUPPORT • Q / / / / \ \\ \\ W AMENDED LIMITS OF g DISTURBANCE = 17.17ac. _ o - w ■ LOCATION OF CONTRACTOR PARKING & \ / V) // // // / i // / /l / I I I I I I I I I I I I / / xs' STAGING AREA WITH PORTA POTTIESw , I \ \ \ \ \ \ / x.oi / DUMPSTER, AND FUELING TANK /FF /— _ _ a arm ua A raf_ / + I I I ♦ I I II\ I\ \ \ \° / � I I -- _� --- _--- —~ o� b7 LIMITS OF PROPOSED TREE CLEARING (TYP.) M — — _ —tD / -- - _ \_ EXISTING PRESERVED — ' / // I _ / /— / STEEP SLOPES TYP_ - - f�' - _ A _ ago - / / / _ / / / _ - -- - - �5_ 0/ / � /j / CONTRACTOR TO ENSURE POSITIVE / � � � � - � _ \ ° � \ � / - _/ DRAINAGE ALONG DIVERSION BERMS �- jam`\//// _/ / ♦ % ( 1 ° \ / / /// - -_- w // / ' // / / / ' pi / / *♦ S (♦ I \ \ AMENDED ESC PH 11 _ / / / / / - ♦ _ / / / 40 - R SB 1 DA=10.41 ac. -/ / / / / / _ - ->• - -34///_r7Z (APPROVED DESIGN / -_ M/T// / - — - - Lu N WWI' \ / \ /�/ / ///// // / ♦i / -O PROPOSED SAFETY FENCE / / / / Q \ / / AROUND SEDIMENT BASIN / / / = IP ° // ♦♦ ��/ / lI 11 // / / / ; ®♦ / ui I— IRE �`. \s w/ PPOR J Cn O I / / U) z x ® / ' /0 3�0✓ .�k / I ° I \ \\ \ I I ♦ \ ° APPROVED CLASS Al OUTLET \// // / / / / D/ \ \ \ in ~ �Y ♦ / / ♦ ° II \ \ J \ PROTECTION w/ GEOTEXTILE FILTER A� \ / /l � w SB UNDERLAYMENT W1=4.5, W2=9.5, D=1.5 MIN. L J H� OP ♦ / I I \�• I EXISTING TREELINE (TYP.) Q \� SEE SHEET 8 FOR RIP' RAP I I ♦ / / ° / / / / aesl \ V �� / I / /� I I I I I I I / / • I i - \ A 0- Q OUTLET PROTECTION W / / / / / A -♦ v DD A \ / / I I ,/ / Q DESIGN & DETAILS R ° / TS / V A ° A w - A \ \\\\ \ V�\ V AA V� / , �__/ III I I I / / / / • I / / / / - Z EXISTING ° / - ` V A \ N \ \ \ \ \\ - / /// _ / I I I I I / •/ / i i--i TREELINE• / / / • \ \\ \_ \ / / - _ ! I I I(TYP.) Lij � z AMEN ED S III I l� I I l I l l / I l I l / • 9 c.- _W O ROVED 48" RCP STANDPIPE ST_P DA= - - _ ��� v v v / _ I / _ I I I I / / / ��� / / ■ (APP ON ED E v v ° \ \ v TO SERVE AS RISER STRUCTURE �43 - �_ Av _ / / /i�_�/ / / / I U) PROPOSED 48' RCP STANDPIPE ° ° ° I - \ \ �� as yy\ VA_A V / // I l / I I I / A-1.26 ) \ \ \ zo \ v\\\���A �,//// /j / CONTRACTOR TO ENSURE POSITIVE ♦ I I I I I I / I �` I I 100' STREAM I I I P° PS / / $C PH II - V Q RISER STRUCTURE I ° A�ENDED E �♦ _ ° \ \ _ �� APPROVED BAFFLLfi 0 E _V� / // DRAINAGE ALONG DIVERSION BERM •I I / / SB #2 DA=2.68 ac. / \ BUFFER L I / / _ - \\ / /� Y / / • I I I I I / / W T RACE R SAS HALL INSTALL THE PERMANENT - \ RREL ET PROTECTION SPILLWAY O THE TIM F �W I / (AMENDED DESIGN / / -- = - APPROVED SAFETY FENCE /// // \ I I I I I I I I \ _ _ W w / _ I I FouNDAT�rv,�l ♦� DA�6.04'ac.) / ° CRS - __ AROUND SEDIMENT ETE ON CELL EMBANKM NT, RISER I I I THE TEE PO RY SEDIMENT SIN s CONSTRUCTION. I ♦♦ / V OW FLOW ORIF E SHALL BE PERMANENTLY BLdCK DONVERS� �. ♦ D � ♦ / V — � � / / I I I�ORINI II II ♦� SOAF NSPECTORPPOV . DGN DETAILS. ♦CRI DING,PNV/ /♦ I I I II I I II / ESI U) O ujE V A \ 0\ V PROPOSED BAFFLE I I I I �= I♦� \ - / i - - - - - _ as - \ / I I I I I / / / / / W Z Q o \ _ \ ♦ v O \ • Lu \ ov \v�� v��vvvvvvv\vVA�� //� ♦v - - — -- / / 1 v v �v v vv v v x \ �♦ v — — 00 I—� o Lu Lu r / w/WIR/ - �\ �-��-�—\- � _ _.�- - x�_- x \A�A\\ v - _ H--�■—� -�— —_—_ // _ _//� // MP M�E � F Worre Lanlo� nUPPORT /D# s D.B,.2544 _39 w� z wD.B 607 pp.' p 1673 gyp(ceD.B� LIMITS OF PROPOSED TREE CLEARING (TYP.) \ - . (9�Q JOB NO. �F \ w/WIRE / rR / OP / -SUPPORT �/ / / 1 1 — — — — — — — 59� /00 20o SCALE LIMITS OF DAM INUNDATION ZONE \ - - - - - _ - _ - - - V7, APPROVED 30" - =J�O \\\ \ APPROVED VDOT CL I RIPRAP WITH - - v RCP - I - �'�-- -- _ - >C _ / / SHEET NO. �/ -� - FILTER FABRIC UNDERLAYMENT. SEE _ _ - - - / _ _ \ \ \V A APPROVED SHEET 7 FOR DETAILS. I - LIMITS OF DAM INUNDATION ZONE (TYP.) _/ / — 4A A \ - - — — / \ / 1 - 5 ft. / 1�1 I/P I� I�l.11lIl �I I���Il �I /�\; Il1\l/ \ I 1 III� I ;//'I'l/�l / I aO/I �� � 1'/II y1�/I ✓ II/ \ II 1II \I IP/r I \I"ll1l. "E�I v.I XIlI_ l\II.I�I�IDIl I /:V � I• yV I Iy I°V I•./Vl�®.;A ��I\VvI IL\\ \��\_ /�_—_ \v—/ —�'\\— V�—,/ _ —��/ /A—,,��— \ � — \/ \� _ \i ,Q \ ,�/— — V_vU—�\—/ C— \�— T_ �—IAO— _ \ —/\,—/V—\N�_v� I _,. �/A� _ \\— �♦,—/ / �II v I_ �I �_��_ \ ,j—\ I\ -I _ -�k-/—\ _ �—/—�fII�\ --I /� v—v��y --/\ i/Ii—I —/\//vv�_ —//i— \ /�\ // —y II/ \_ v=—=/--—\— //•— \—/// \_Q.\ / -\y— i/�4/-- �/—//-3v—_--�yj—�_, _ / —_v � / � \ A// �/v /_— v- _A —y '//�— � — ,�-_ma� -Iv �_ / v— ��/ \—y, vi--o \3�-_II, /v i-�� -'y —+/\-\\��v�/— j IA � i —/�/ �// �\v�/\\�j/ //V1 '/� \/ o�//I VAo//,v/ ///_/i / ,/,/. \ =\ Ai/ �/ /i\\\ � �//1 /0y °/i/// /-/Io3 ♦ / // / /A�,/ / /—i� / \/ (� �y/�—/� /// �// ;�\ >/ / �// // ,_/ •// —/�ov-v/ / � //\ y A\/I I �i—� _� '/ y /— // /�\//• A_� / �0_/ \ /i // //� ���/� � i —/x �/ / �,/// / / // /��o��/ \// — / o/�I \ \ \// iA i /_//��// i///\ � x / //i/ ,�///��—/,� /'\ /�� �� - \/// :o \—/�, P/ //i —\ //� // ///i/ _-/ �.// /'/ �:� \��/� © �/. /_�I:/ �/ �///// /I-.. _. _ �/// \/ _1i / // / ♦ � / 1 // � /—/ / /////I / /./// \,� /, I ,/// / // —: /— / 1,I / // I/ ///// // I /// //I /// /=///y//i / y// / , i_ /� p�//, � /\ / / I \1IA \� � ��_I�I i T�I� �i\ i��� ® I:� 1 . I\1 —;I1 �� �I-1 / y/I1 II vI�\' I � I 1 /I/I \1 1 I I- ,/� , I /,� /I // / :\ II�� �IU I /� //l©1/ I 1/ I I � ,I � /_11\ // I I o I �I /I o:��/ y/ .°/ �/ IS :��/f I /! // .I T�� I�/H�i J/`I / � /IE_/// �SI '/ . vE•/ / .F/ /I l - /�/ i- / / I/vI 'II�I\I� Il\ I/1I /�/i �/�DI// / /II " D/ \\ �>/\ ti%�Ii� I /♦♦I i- xl/-/I� _■�I / I� I �♦I I ♦ J■I/ iI i � x �/I �I r ♦I/ I♦ i�.IA(iTI /IMyI� IE IPO I/ / As N � -(�/� I-EI -\ A\�R- 1/I � �/I / S,I �v �i—TI� /_<- PI:R_ 1./�•_ � _-- U— j/xII�\ C�-I:/ I v :TII —1` P-- U\I�• \ pI\/ �I R• \ •\I c '— /' s 'h.•``,' � / I ., IA ./ \\�/\�' �,Is�A / •/\ . -\JPo- /op ; ,o\:� o�/\E1V f sX/\' o :.��•D�.i\\\1I �,v I:\\,��\ '♦P� \ s� 1\A♦y�f\ \ \\ •.0�\. " \v\` I \ •..\\ v\\_\�rA \ � \� - -/\\\�`\-�' �_♦� / /si- \.-� _♦- ° \i'//-_\�- ///,%� �/\V/,/\`�//°/° \/v/ ° /� — /�v •�I ` _♦�.=\�._ \ ,,\A� ♦� �\ --� ♦� \ •♦,°,\�/— ♦ Wyi�\—� ���/ '— A/ \ A�\\ �//■M� \ � �I/�o� s• °o°/—I Io y IA_/ o �Li� ,: _ � .V.i /A/� \ •1 \ / °I_ /x�\•� `•�0�Cl �� � /o� SJ. \o , � �/_ � I_/— _�l V_—I/ �/ i \I l —— )/—. I— I ,� I— /_ --.°� � ' : �/ / -/♦o/ / 0l �:/ o♦I — •/ X// �/ D/\ / y/I � �I/� Q \I/� /�-P � � — .�/\ ♦IIr � —I/l� I I _I\�// I/; I •I� /II�/ , IwI/ / I / II/�II'/ �I♦/ _I♦II II i / — I/I i/ �/ \■I// // / I — \ — �/. - U�zovz�" S� C O ;mzTTCc`N�Q— �_�rIQti�Yv��\`QpzLuazgo'o-"'c' NRLLINS�! oNo. 35791 CONC 6/1/20 �A= 0.56 aC. ONAL GN DA=1/1.2*a ) -440— 1 E HE SC LI T F DISTURBANCE BOUNDARYIS ED TO DEFINE THE RRM BOON RY FOR SWM T R QUALI C CULATIONS. w/ WIRE SUPPORT F N0EXISTING TREELINE (TYP.) 4-0 o � w PROPOSEDSAFETY / FENCE AROUND SEDIMENT TRAP Qw SEET ST1 oF * 0. U ID�S1 Q � / w/WIRE > wSF SUPPORT w / �cn AMENDED LIMITS OF E=17.17ac. DI&T-URBANCLOCATION OF CONTRACTOR PARKING TISTAGING AREA WITH PORTA POT ES. >wDUMPSTER, AND FUELING TANK �37�yw o LIMITS OF PROPOSED 47� TREE CLEARING (TYP.) EXISTING PRESERVED ® STEEP SLOPES (TYP.) 390' L9 _350' CONTRACTOR TO ENSURE POSITIVE � DRAINAGE ALONG DIVERSION BERMS --100" w // / / /gyp EE / / \SB #1 DA_7.84 a DI P ROVED D\ / _'3� %/ 0// / DD (APPC.)// w CN ok 0)6u SF MA INE, PROPOSED SAFETY FENCE AROUND SEDIMENT BASIN EET S Ell SHEE S 4& 4a I I iII mi I- w w EL J SF SUPPORT w rie UUW 0 EXISTING TREELINE TYP. J SEE SHEET 8 FOR RIPRAOUTLET PR TEC TION Lu DESIGN &DETAILS EXISTING U TREELINE 0zzG�F1--� 6 (TYP.) W RCAILW 0 � PROPOSED 48 RCP STANDPIPE n TO SERVE AS RISER STRUCTURE CONTRACTOR TO ENSURE POSITIVE O 100 STREAM _DRAINAGE ALONG DIVERSION-BER BUFFER OR SHALL INSTALL THE PERMANE ENCE w WCELL BANKM NTPRISER FOUM RREL, ' ETROTECTION&SLWAYATTWDETE ION �THETE P YSEDIMENT SIN's CONSTR OW-LL BE PERMANENTLY BLOCV) TERPHASES. CONVERSION OF BASIN U) OWSHALL L O AF q INSPECTOR APPROVAL. / SHEET DESIGN DETAILS. P AllPROPOSED BAFFLE w Q oCwLL� 40_ Lu omi WIRE MR z ��orre Developm n� z 5o 00000, Vl 6 =pp7T3 wpta � w JOB NO. HS PSUPORT -- A�IW/W1172131 At - LIMITS OF DAM INUNDATION ZONE - y y — y \ — _ = �5 / '�// / / / / zoo' SCALE APPROVED 30" " — _ —_ — - - - — — —370— / -J�O _ APPROVED VDOT CL. I RIPRAP WITH _ _ ION \ V���\ ` ` - RCP BARREL �— — — _ _ _ - — FILTER FABRIC UNDERLAYMENT. SEE _ _ _ �� SHEET NO. �� \ �_ • v vv v _A VAA VA \ �� — — / // / // / / / ��\\ \� APPROVED SHEET 7 FOR DETAILS. -- LIMITS OF DAM INUNDATION ZONE (TYP.) �v \ \\\ _ 48 _ - - 1 %i li = 0 /ft/ / / COMPACTED SOIL - FILTER FABRIC ENTRENCHED 6" 31 MINIIIUIt y�tttY s' DD TEMPORARY 18" DIVERSION BERM 1992 3-W iN2 SILT FENCE CULVERT INLET PROTECTION DISTANCE IS 6' MINIMUM IF FLOW IS TOWARD EMBANKMENT FLOW OPTIONAL STONE COMBINATION FLOW I RIPRAP T'VDOT #3, #357 OR #5 COARSE AGGREGATE TO REPLACE SILT FENCE IN " HORSESHOE " WHEN HIGH VELOCITY OF FLOW IS EXPECTED Source: Adapted from VDOT Standard Sheets and Va. DSWC SHEETS OF 4'x8 xj' EXTERIOR PLYWOOD OR EQUIVALENT 11 I I I I II 4' I I I I II I I 8' SEDIMENT BASIN BA APPROVED Sediment Basin #1 Design drainage area (acres) 12.00 basin volumes: (using 2' contour intervals) elevation (ft) contour area (sf) volume(cy) 374.00 3270.0 0 376.00 4626.0 291 378.00 6198.0 690 380.00 8011.0 1215 382.00 13798.0 2013 384.00 20485.0 3275 wet storage: wet storage required (cy) (67*DA) dewatering orifice elevation (ft) wet storage provided at this elevation (cy) available volume before cleanout (cy) (34*DA) cleanout elevation (ft) distance from cleanout to orifice (ft) (> 1') dry storage: dry storage required (cy) (67*DA) principle spillway crest (ft) dry storage provided at this elevation (cy) diameter of dewatering orifice (in) diameter of flelable tubing (in) (orifice+2") runoff: C (use 0.45 for bare earth) tc (min) 12yr 4.0 Q 2yr 125yr 6.7 Q 25yr principle spillway: available head (ft) diameter riser (in) spillway capacity, Qp (cfs) diameter trash rack (in) barrel length (ft) head on barrel through embankment (ft) Plate 3.08-1 diameter of barrel in 1992 STONE 7D' MIN.- :01~15nucWN ACCESS 3" 510-24 ASPWIILT TOP couasir: EXISTING. z1e zx PAVEMENT a 6 MIN_ 71A ACC HLwLIL BASE -PROFILE STONE 711 M:N. COKSTRUC11014 ASPHALT PAVED ACCESS 0 WASHRACK LX15TING J 2X 2% PAYEMENT 2% 12' WN -- - *MUST EXTEND FULL WIDTHA TO DE or it ckss ANo cCREss 1-TRAPPINGSEDIDEVICE OPERATION ELM 12' W N. Q j" IVE PMNAUL 7r0 SEDIMENT TRIPPING DEVICE Wrs.c-r' ti f`ILTER CLOTH SECTION A -A X nlirtuatw.I wale tall of 1l etch littI be mWalletl Mich a alotilltllnl I ateh ballcuck s111*011f vah-e glippt► ka a wad] 60+e ►r11:11 a (4alltehn of 1 .; inch" for ade.luate eal�stautt l>'rexsyur. �1�aal] vrntet uR>I�t be c�lllrcl na•n}hnlll tits eahu�ce to aIt a�rraz'ed xettluLa aI ea to Ietlln►'r r?ecluneld dill necituletll �t3+itl Ue }�1e1'ealted y olu ti]1cmix stoun shawls. ditches or watac-ourSCS. PAVED WASH RACK NO SCA.-F 3.01 SAFETY FENCE III 1 's� eie�• J � i Ilf ;1 PERSPECTIVE VIEW PERSPECTIVE VIEW PLASTIC FENCE Source: Adapted from Conwed Plastics and VDOT R idge Standards PERSPECTIVE VIEW METAL FENC= Plate 3.01-1 VL Cc 157 NO SCALE F RISER CREST ELEVATION I I I POSTS MIN. SIZE 4" SQUARE OR 5" ROUND. SET AT LEAST 3' INTO THE GROUND -E DETAIL DESIGN HIGH WATER �.(25-YR. STORM ELEV.) MIN. 1.0`''�}'' DRY " STORAGE " WET " STORAGE SEDIMENT CLEANOUT POINT (' WET ' STORAGE REDUCED TO 34 C.Y./ ACRE) MIN. 1' W1 SPILLWAY CREST OF EMERGENCY 2' WITHOUT �SPILLWAY RISER CREST DEWATENG De.10E RI 804 design high water 382.25 378.43 top of dam (ft) 384.00 804 top width of dam (ft) 10.0 408 bottom of basin (ft) 374.0 376.56 approx bottom dimensions: 38'x130' 1.9 upstream face slope: Varies downstream face slope: 3:1 804 baffles: YES 381.25 length of flow, L (ft) 125 910 effective width, We (ft) 89.544 8.0 L / We (baffles required if < 2) 1.4 10.0 collars: YES depth of water at spillway crest (ft) 7.25 0.45 slope of upstream face (Z:1) Varies 11 slope of barrel (Sb) 8.80% 21.6 length of barrel in saturated zone (Ls) 34.48 39.8 number collars required 2 dimension of permanent collars 6.9'x6.9' 1.00 emergency spillway: Yes 48 required capacity (Q25-Qp) (cfs) 0.0 40.0 bottom width (ft) 100 72 slope of elast channel (ft/ft) 33% 99.45 minimun length of e)at channel (ft) 36 9.75 crest of spillway (ft) 382.75 30 3.11 1992 TEMPORARY RIGHT-OF-WAY DIVERSIONS TYPICAL GRAVEL STRUCTURE TYPICAL EARTHED STRUCTURE Source: Va. DSWC APPROVED SAFETY FENCE AROUND SEDIMENT TRAP / °o \ \ APPROVED SEDIMENT TRAP #2 & SEDIMENT BASIN #1 DETAIL TH 0 SCALE 1 "=30' ��P_ \\\ \\ STA TO \ \ \ RIS UCT SER \ \ SC OTT R. LLINS O - - \ \ No. 35791 � \ \ V A N N PRO SER BE EMBEDDED \ \ A 6/1/20 MO O A ETE E. ', \ \ \ \ \ �SSIONAL CRE E DIM NS: L= =8', D=1.5' � � /372 \ - - - _ A O SAFETY FENCE U SEDIMENT BASIN 7 5' MI O DAM 378 / � I7 \ °a AIIII -C _ v APPROVED STONE WEIR OUTFALL _ (L=8', W=7.6', D=25) f a \ PIPE OUTLET CONDITIONS e e 3.18 PIPE OUTLET TO FLAT AREA WITH NO DEFINED CHANNEL PLAN VIEW L a OPII- II d SECTION A -A FILTER CLOTH KEY IN 6"-9"; RECOMMENDED FOR ENTIRE PERIMETER A A 3do (MIN.) do PIPE OUTLET TO WELL DEFINED CHANNEL PLAN VIEW L a o% - d SECTION A -A FILTER CLOTH KEY IN C-9"; RECOMMENDED FOR ENTIRE PERIMETER NOTES: 1. APRON LINING MAY BE RIPRAP, GROUTED RIPRAP, GABION BASKET, OR CONCRETE. 2. La IS THE LENGTH OF THE RIPRAP APRON AS CALCULATED USING PLATES 3.18-3 AND 3.18-4. 3. d = 1.5 TIMES THE MAXIMUM STONE DIAMETER, BUT NOT LESS THAN 6 INCHES. -- Plate 3.11-1 Source: Va. DSWC 1992 Plate 3.18-1 3,32 TABLE 3.32-D SITE SPECIFIC SEEDING MIXTURES FOR PIEDMONT AREA Total Lhs- Per Acre Minimum Care Lawn Commercial or Residential 175-200 lbs. • Kentucky 31 or Turf -Type Tall Fescue 95-100% Improved Perennial Ryegrass 0.5% Kentucky Bluegrass 0.5% High -Maintenance Lawn 200-250lbs. Kentucky 31 or Turf -Type Tall Fescue 10090 General Slopc (3:1 or less) Kentucky 31 Fescue 128 lbs. • Red Tap Grass 2 lbs. Seasonal Nurse Crop 20 lbs. 150 lbs. Law -Maintenance Slope (,Steeper than 3.1 Kentucky 31 Fescue 108 lbs. Red Top Grass 2 lbs. Seasonal Nurse Crop* 20 lbs. Cruwnvetch 20 1b5, 150 lbs. ' Use seasonal nurse crap in accordance with seeding dates as stated below: February 16th through April ...... . .......... . .... Annual Rye May Ist through August 15th ....... . . ........ . ... Foxtail Millet August 16th through October .... . ... . ...... . .. . . . Annual Rye November through February 15th , .... . ......... . .. . Winter Rye " Substitute Sericea lespedeza for Crowuvetch east of Farmville, Va. (May through September use hulled Sericea, all other periods, use unhulled Sericea). If Flatpea is used in lieu of Crownvetch, increase rate to 30 lbs./acre. All legume seed must he properly inoculated. Weeping Lovegrass may be added to any slope or low -maintenance mix during warmer seeding periods; add 10-20lbs./acre in mixes, - AMENDED Sediment Basin #2 Design drainage area (acres) 6.04 basin volumes: (using 2' contour intervals) elevation (ft) contour area (sf) volume(cy) 352 4631.0 0 354 5961.0 391 356 7393.0 885 358 8925.0 1488 360 10557.0 2209 wet storage: - - \ - - _ OVED BAFFL tap, o - •. \ \ � \ N - \ \ \ \ Ln LU o z \ - o U Ln- m U J - v� I o Q � v \ \ 10' OP OF DACV A z U _ \ �- -�� A W LU z V) > LU co a APPROVED 100' WIDE RIPRAP LINED EMERGENCY SPILLWAY - CREST ELEV.=382.75' APPORVED / � - \ \ 30" RCP _ \ BARREL AMENDED SEDIMENT BASIN #2 DETAIL W � N - N DESIGN HIGH WATER (25-YR. STORM ELEV) MIN 1.0' DRY " STORAGE ... " WET " STORAGE SEDIMENT CLEANOUT POINT ( TO 34 STORRAGERR DUCE - MIN. VW SPILLWAY 2' WITHOUT RISER CREST DEERING DEMVICO E CREST OF EMERGENCY i SPILLWAY wet storage required (cy) (67*DA) 405 design high water 356.75 dewatering orifice elevation (ft) 354.05 top of dam (ft) 360.00 wet storage provided at this elevation (cy) 405 top width of dam (ft) 10.0 available volume before cleanout (cy) (34*DA) 205 bottom of basin (ft) 352.0 cleanout elevation (ft) 353.03 approx bottom dimensions: 32'x140' distance from cleanout to orifice (ft) (> 1') 1.0 upstream face slope: 2:1 downstream face slope: 3:1 dry storage: dry storage required (cy) (67*DA) 405 baffles: YES principle spillway crest (ft) 355.75 length of flow, L (ft) 49 dry storage provided at this elevation (cy) 823 effective width, We (ft) 147.102 diameter of dewatering orifice (in) 5.0 L / We (baffles required if < 2) 0.3 diameter of flelable tubing (in) (orifice+2") 7.0 collars: YES runoff: depth of water at spillway crest (ft) 3.75 C (use 0.45 for bare earth) 0.45 slope of upstream face (Z:1) 2:1 tc (min) 5 slope of barrel (Sb) 0.50% 12yr 5.2 Q 2yr 14.1 length of barrel in saturated zone (Ls) 22.96 125yr 7.5 Q 25yr 22.4 number collars required 2 dimension of permanent collars 3.1'x3.1' principle spillway: available head (ft) 1.00 emergency spillway: Yes diameter riser (in) 48 required capacity (Q25-Qp) (cfs) 0.0 spillway capacity, Qp (cfs) 40.0 bottom width (ft) 50 diameter trash rack (in) 72 slope of east channel (ft/ft) 33% barrel length (ft) 64 minimun length of e)at channel (ft) 6 head on barrel through embankment (ft) 6.75 crest of spillway (ft) 358.66 diameter of barrel (in) 24 APPROVED Sediment Trap #2 Design drainage area (acres) (<3) 1.26 trap volumes: � 1'1 .VARIABLE.• I elevation (ft) area (sf) volume(cf) volume(cy) I I 368.00 432.0 0 0,0 CREST OF STONE WEIR VA}21ABLE" GROUND GROUND `\ 370.00 660.0 1,084 40.1 ELEV. 372.00 921.0 2,658 98.4 374.00 1538.0 5,091 188.5 DRY STORAGE N c VARIABLE 376.00 2282.0 8,886 329.1 378.00 3135.0 14,281 528.9 WET STORAGE 4' MAX. / (EXCAVATED) I CLOTH ORIGINAL ,FILTER GROUND ELEV. wet storage: wet storage required (cy) (67*DA) 84.4 .SEE PLATE 3.13-1 COARSE AGGREGATE•• CLASS I RIPRAP bottom of stone weir (ft) 372.00 wet storage provided at this elevation (cy) 98.4 slope of wet storage sides 1:1 weir length (ft) (6) DA) 7.6 dry storage: bottom of trap elevation (ft) 368 dry storage required (cy) (67*DA) 84.4 bottom trap dimensions: 43'x10' crest of stone weir 377.00 top of dam elevation (ft) 378.00 dry storage provided at this elevation (cy) 330.6 top width of dam (ft) 5 slope of dry storage sides 2:1 top trap dimensions 75'x42' i APPROVED I O' WIDE - / / TOP OF DAM ELEV.=360' 50' WIDE RIPRAP LINED EMERGENCY SPILLWAY CREST ELEV.=358.66' / SCALE 1 "=30' Q III, i • j.�•'1lI'� ' I� � Ittt� > v PROPOSED a / BAFFLES / / ° / / / / LLi J 1 06 / / a LU LU k LD F__ F--- P O O DS E Y O OC 0 SEE THE'DRY ° a N EAR U D / J J DETENTION CELL a E I N T A a O ISECTION' PROFILE I Q Q N SHT. 8 FOR THE I = LL CONSTRUCTION OF THE OUTFACE a a ;, CONTRACTOR TO INSTALL THE RISER f , SYSTEM: ° FOUNDATION &THE VDOT MH-1's LOWER C) 0 z I I a 048" RISER BASE. 048" RISER BASE TO W 0 CONTRACTOR SHALL INSTALL THE PERMANENT °o a o SERVE AS THE RISER STRUCTURE. H O (DRY DETENTION CELL EMBANKMENT, RISER TEMP. 048" RISER RIM ELEV.= 355.75. LU w FOUNDATION, BARREL, OUTLET PROTECTION & / CONTRACTOR SHALL WAIT TO INSTALL U\ SPILLWAY AT THE TIME OF THE TEMPORARY RWD THE VDOT MH-1 TOP SECTION FOR THE SEDIMENT BASIN's CONSTRUCTION. LOW -FLOW I I PERMANENT FACILITY's RISER RIM UNTIL L.L � ORIFICE SHALL BE BLOCKED WATERTIGHT THE TEMPORARY BASIN IS CONVERTED in U) Z DURING ESC PHASES. CONVERSION OF BASIN I I TO A PERMANENT SWM FACILITY. LU SHALL ONLY OCCUR AFTER ESC INSPECTOR I J APPROVAL. SEE SHEET 8 FOR ADDITIONAL Q DESIGN DETAILS. I �+ LL! 1--1 Zw0 1. SET POSTS AND EXCAVATE A 4'X4" 2. STAPLE WIRE FENCING TO THE POSTS. w TRENCH OF POSTSPSLOPE ALONG THE LINE V) O = Cid Lij O z r l l l U L1 O/ Q LL- clL _ III -I I L _I III III- LL 6 FLOW 4N" - ui Uj �q+ n 3. ATTACH THE FILTER FABRIC TO 4. BACKFILL AND COMPACT THE ATTACH FILTER EA13RIC THE WIRE FENCE AND EXTEND EXCAVATED SOIL. TO STAKES OR POSTS & EXTEND IT INTO TRENCH IT INTO THE TRENCH. WOODEN STAKE OR STEEL POST LENGTH = 5' MIN. U LU LU 0 LU 0- (n EXCAVATED SOIL T 'f J� JOB NO. BACKFILLED COMPACTED AND (� l � 172131 FLOW I -I I- �- IliI=1111=11I1 ((r III (III- =III 4"x4" TRENCH SCALE SILT FENCE EXTENSION OF FABRIC AND WIRE INTO THE TRENCH. AS SHOWN SF (WITHOUT WIRE SUPPORT) 05-2 SIL T FENCE SHEET NO. NO SCALE S WITH WIRE SUPPORTS 05-2 5 AMENDED POST -DEVELOPMENT SWM PLAN: SCALE I "=80' - - FEDERAL-DA_ BIR /- - ._. 196`-W PO STREAi�fi- -- / /O• ' ..- / _ � INt}NflA ZONES � �_ � � PF�S >, - A aeo 7CO E P. O / DRY DST NT N L / - �_ i �I PR V DES WATER i /�� _ A T T EA E O LYo -- - - _ - � � � ,� _ -. - - I r \ l / / C • / ,.. _ _ AMENDED DAB \ ✓ / � . I / / / Tc= 0.10 hrs. �� --� A / THE ESC LIMITS OF DISTURBANCE USED TO DEFINE THE I I� / _� _ - _ VPRIM BOUNDARY FOR SWM WATER � � _ � I/ - - QUALITY CALCULATIONS. SEE SHEET • / �� / - �/ f d ��� \ - -- �,I 4B FOR FULL DEPICTION OF ESC LIMITS OF DISTURBANCE. I ; 0•, BIOFILTER SUBAREA=0.32ac. 5- V ` (0.21ac. IMPERVIOUS &- \ • 0.11ac. MANAGED TURF) I Ilk J Ago-- ® - • \ J f: b \ SEE SHEET 8A FOR C \ \� BIORETENTION BASIN I ` N i APPROVED DA A DESIGN, TREATING A � ''• � .'� _ \ �PORTION OF BUILDING 6's / - 6.02 ac.4.4 / . ROOFTOP RUNOFF CN=84.4 - _ \ � Tc= 0.10 hrs. \ / v _ o 1 \ rEDL-F,tALaAM \ INUNDA�� ZONi= C1 G3 � - s L i / 11 _ \ \ ------------------ \ \ \ 11 \ 3 V \ •� O•I I I ���\6\ r rt- I II i PARCEL LIMITS, TYP. \ � �31 I E ST�EE �O E E E I E \ o\ \ �\ I ;':.- � PES TYP. � \O�RO(IDE �\ VV A TER UAL / \ AT\\ (� / _ _ - _ = y _ --DEVELOPMs/ 4 - _ - _ _ _ -- _ _ APPROVED PkE ENT SWM PLAN: - - SCALE 1 "=80' l /' _ __FEBERAL� _BfiEA 1W WPO-STREAM- -MWNDA - P S 4 BUFFER, TY_Pr _ �- � �/ \ J�36' 36 / - -�-� _ I1IOOF/�R��VED IL ITY // • /// /\/ /��/ �� // A13PR9 D_ I I i A EA UP Der SS DEFINE THE � THE ESC LIMITS OF DISTURBANCE ey I BOUNDARY IS USED TO I�JFFE �T,E-��LO �� / / l 1 I / /� VRRM BOUNDARY FOR SWM WATER T BE E P QUALITY CALCULATIONS. SEE SHEET Atiprcc C.�� I 4B FOR FULL DEPICTION OF ESC /�/ / / C = 0 / _/ I I I LIMITS OF DISTURBANCE. 39 \ \ 1 I\ I \ I ( I I \ \ \ 1 �� / / / / 10OF\ O�F %\ 0=116 1(Tc 0.10 hls.)I \ \ \• I / / I I \ \ �. 3�� \ / / / / / 635' OF CIF w A=70' (Tc 0.03 h s.) �\ \ I � I a �Y - I ° F DAL DAM A \ \ \ I NDA� ZONi= \ P� Io1616\ \ \ \ \ 1 0 � / �j-- Y00' OF OiF w� =1�' (Tc 0. 9 hrs. \ \o\ \ =��_ s 77 5 �F Cal 84' (T 0.04 hrs. � III \ LC AA�IOI 01` PRR D I I� 460- \ APPROVED DA A P or \ \ \ 7.62 ac. \\ \ \\\\\\\\ \ CN = 64.2 Tc- 0.13 hrs.�x O �-PARCEL LIMI'i5, \\TYP. � y _ V "General Construction notes for stormwater Management Plans \ 1. All dams and constructed fill to be within 95% of maximum dry density and 2% of optimum moisture content. All fill material to ARIA%E�\ EE� be approved by a geotechnical engineer. A geotechnical engineer is PES, TYP. to be present during construction of dams. 2. Pipe and user joints are to be watertight within stormwater management facilities. �41 �� I 3. For temporary sediment traps or basins which are to be converted �-�® %� \ A ( I to permanent stormwater management facilities; conversion is not to take place until the site is stabilized, and permission has been obtained from the County erosion control inspector. STORMWATER MANAGEMENT NARRATIVE: OVERVIEW THIS PROJECT IS FOR THE DEVELOPMENT OF AN APARTMENT COMPLEX, AND ITS ASSOCIATED INFRASTRUCTURE. STORMWATER TREATMENT IS PROVIDED TO MITIGATE THE IMPACTS FROM THE PROPOSED IMPROVEMENTS. THE STORMWATER MANAGEMENT PLAN COMPLIES WITH PART IIB SWM REQUIREMENTS. WATER QUALITY SUMMARY THE PROPOSED DEVELOPMENT REQUIRES A TOTAL PHOSPHOROUS REMOVAL RATE OF 13.17 13.60 Ibs/yr. THE STORMWATER QUALITY REQUIREMENTS FOR THIS DEVELOPMENT ARE MET THROUGH THREE BEST MANAGEMENT PRACTICES. THE BEST MANAGEMENT PRACTICE OF INSTALLING A LEVEL II WET POND TREATS MORE THAN HALF OF THE PROPOSED IMPROVEMENTS. THE LEVEL II WET POND PROVIDES A PHOSPHOROUS REMOVAL RATE 6.93 Ibs/yr. A LEVEL II BIORETENTION BASIN TREATS 0.45 Ibs/yr. THE REMAINING WATER QUALITY BALANCE OF 9; :24 6.22 Ibs/yr OF PHOSPHOROUS WILL BE MET VIA THE BEST MANAGEMENT PRACTICE OF PURCHASING NUTRIENT CREDITS. WATER QUANTITY SUMMARY THE PROPOSED LEVEL II WET POND (DA A) CAPTURES MORE THAN HALF OF THE PROPOSED IMPROVEMENTS & ATTENUATES ITS SUBAREA's RUNOFF. A SIGNIFICANT PORTION OF THE REMAINING PROPOSED IMPROVEMENTS RECEIVE WATER QUANTITY TREATMENT IN SUBAREA B. SUBAREA B RECEIVES ATTENUATION IN A PROPOSED DRY DETENTION CELL (DA B) FOR WATER QUANTITY TREATMENT. THE PROPOSED PLAN COMPLIES WITH MINIMUM 9 VAC 25-870-66 REQUIREMENTS. PLEASE SEE THE ATTACHED CALCULATIONS PACKET FOR EVIDENCE OF THIS PROJECT's CHANNEL AND FLOOD PROTECTION COMPLIANCE. Existing Impervious Area Summary (DA A- Water Quantity) Existing Gravel Access 2,250 sf Proposed Impervious Area Summary (APPROVED DA A, Water Quantity) 'roposed Buildings 52,750 sf 'roposed Pool & Community Space 11,475 sf 'roposed Sidewalk 14,925 sf 'roposed Parking & Access 86,475 sf 165,625 sf Proposed Impervious Area Summary AMENDED DA B, Water Quantity) 'roposed Buildings 46,175 sf 'roposed Sidewalk 16,775 sf 'roposed Parking & Access 82,450 sf 'roposed Garages 3,650 sf WATE SHED SUMMARY APPROVED Subarea A CN Area, ac. 149,050 sf 1-year Flow, 2-year Flow, 10-year cfs cfs Flow, cfs APPROV D DA A (Pre-Dev.) 64.2 7.62 4.49 8.04 20.87 APPROVED DA A (Post-Dev.) 84.4 6.02 0.92 2.85 13.23 AMENDED Subarea B CN Area, ac. 1-year Flow, 2-year Flow, 10-year cfs cfs Flow, cfs APPROV D DA B (Pre-Dev.) 60.6 4.09 1.55 3.09 9.29 AMENDED DA B (Post-Dev.) 83.3 5.69 0.30 4.81 20.86 Total Ara Summary Pre -Development DA A & B 11.71 ac. Post -De elopment DA A & B 11.71 ac. NOTE: THE DISTURBED AREAS OUTSIDE OF SUBAREA A & B's LIMITS RELEASE RUNOFF IN A SHEET FLOW MANNER AND ARE NOT RELEASED IN A CONCENTRATED FASHION. Total Proposed Impervious Area Summary Water Qualit 'roposed Buildings 98,925 sf 'roposed Pool & Community Space 11,475 sf 'roposed Sidewalk 38,025 sf 'roposed Parking, Garages & Access 177,975 sf 326,400 sf _c5 SCOTkR.LL S'z CJ No. 35791 �0Als��IONAL 6/1/20 ��0�E� 0 N N Ln 0 w (� Q V) r/ Z z � ¢ w w mO 0 VZi J Z z Q O U w LU LUa V) C g 04 w O o H N N Q M �I U-1 � M N LJJ CM Q � z N U) 0 Q J CN W Q � LU J F- U) z LU L9 O cl� a � a Q = � U O l p LU W U Q LU LU Ir-I ® Cn O JLU z O J Q CD w -- o LL o LL -= N � z Q z 11J 2 W Q z Q w Q C� G 0 LU w LU a JOB NO. 172131 SCALE AS SHOWN SHEET NO. 6 STORMWATER MANAGEMENT FACILITY GRADING Elevation (ft) Area of Forebay Cell Contours (sf) Volume (Cf) 376 505 0 378 1,534 1,946 379 2,187 3,797 380 2,933 6,348 382 - - 384 - - Elevation (ft) Area of Wetland Cell Contours (sf) Volume (Cf) 376 - - 378 - - 379 328 0 380 878 581 382 - - 384 - - PROPOSED 2' WIDE FOREBAY CONSTRUCTED OF GABION BASKETS FILLED WITH VDOT CL. Ai STONE. TOP OF FOREBAY DAM ELEV. IS 38o'. FOREBAY TO INCLUDE A io' WIDE, i' DEEP WEIR TO CONVEY FLOWS TO THE WETLAND CELL. FOREBAY WEIR CREST ELEV.=379.0'. 390 Elevation (ft) Area of Main Cell Contours (sf) Volume (Cf) 376 177 0 378 1,089 1,137 379 2,197 2,748 380 4,500 6,028 382 - - 384 - - PROPOSED 2' WIDE FOREBAY CONSTRUCTED OF GABION BASKETS FILLED WITH VDOT CL. Ai STONE. TOP OF FOREBAY DAM ELEV. IS 380'. FOREBAYTO INCLUDE A io' WIDE, 1' DEEP WEIR TO CONVEY FLOWS TO THE MAIN CELL. FOREBAY WEIR CREST ELEV.=379.0'. Elevation (ft) Total Facility Area Contours (sf) Volume (Cf) 376 682 0 378 2,623 3,095 379 4,712 6,712 380 8,311 13,139 382 14,412 35,584 384 20,500 70,317 EMBANKMENT NOTES: AFTER AN INVESTIGATION OF THE SITE's SOILS, SITE VISITS, AN ANALYSIS OF THE SURVEYED TOPOGRAPHY AND AN EXAMINATION OF VA DEQ APPENDIX A: EARTHEN EMBANKMENT (REQUIREMENTS vs. RECOMMENDATIONS), THE APPLICANT HAS PROVIDED A COMPREHENSIVE EMBANKMENT DESIGN THAT DOES NOT NEED A GEOTECHNICAL STUDY AT THIS TIME. SUCH IS THE CASE DUE TO THE PRECAUTIONARY EMBANKMENT DESIGNS PROPOSED. A SUMMARY OF THE EMBANKMENT DESIGN REQUIREMENTS ARE LISTED BELOW, MANDATING THE CONTRACTOR MEETTHESE REQUIREMENTS ATA MINIMUM. THE EMBANKMENTS SHALL HAVE A COMPACTED CLAY CORE WITH A CUTOFF TRENCH & BE IN ACCORDANCE WITH THE DETAILS SHOWN ON THIS SHEET. BERMS AND SPILLWAYS SHALL BE STABILIZED WITH EC-3 MATTING WHERE RIPRAP IS NOT PROPOSED, AND THE REMAINING DISTURBED SLOPES SHALL BE STABILIZED WITH EC-2 MATTING. ALL ADDITIONAL BERM FILL MATERIAL SHALL CONSIST OF ML, CL, SC OR GC SOILS & BE FREE OF WOOD, ROOTS, ROCKS OR ANY OTHER NON COMPACTING SOIL. COMPACTED FILL SHALL BE PROCTOR MAXIMUM DRY DENSITY ASTM D698 AND HAVE A MINIMUM OF 95% OF MAXIMUM DRY DENSITY AND 2% OF OPTIMUM MOISTURE CONTENT. ALL FILL MATERIAL AND PROPOSED CONSTRUCTION SHALL BE APPROVED BY AN ONSITE GEOTECHNICAL ENGINEER PRESENT DURING THE CONSTRUCTION OF THE EMBANKMENTS AND FILL AREAS. 390 PRO OSED M SE= 38o o' / (PERMA NENT POOL DEPT =4') ESC RIS R FOUN ATION LOWER PORTIO OF ITS 48" CL. III RCP TANDPI E PROPOSED 10' (ESC RIM ELEV =381.25) TO REMAIN. CONTRACTOR SHALL MODIFY THE TOP 385 WIDE OP OF PORTION OF THE ESC RISER TO HAVE A VDOT MH-1 UPPER CONE. CO TRACTOR 3g5 DAM EL V.=384' INSTALLING THE MH- FRAME & COVER.. SWM FACILITY EW RISER RIM WETLAND ELEV.=381.75'. CONTRA OR SHALL PLUG, WATERTIGHT, T E ESC C RIFICE & CELL INSTAL ONE NE 06" LC FLOW ORIFICE (INV.=3 0.00) ITH A T ASHRAC XISTING PROP SED 10' -- WIDE TOP OF 380 GRADE \ DAM E EV.=38 '. 380 �i PROPOSED io' WI E,12" �f ME DEEP AQUATIC BENCH FOREB Y CELLVALVE TO SERVE AS A DEWATERING ORIF CE. VALVE TO BE IN THE 375 SHUTOFF POSITION DURING NORMAL OPERATIONS. VALVE 375 HANDLE:TO BE LOCATED T THE RISER'S IM ELEVATION OR JUST BELOW IT. VALVE / ORIFICE OPENING T6 BE PRO OSED \ LOCATED AT THE BOTTOM OF THE POND, INVERT ELEV = GRADE 376.00 VALVE / ORIFICE OPENING COINCIDES WITH THE PROPOSED 4' EEP BOTTOM OFT iE FACILITY FOR EASIER AINTEN NCE (FLO OREBAY R ELEV. 376') IN .OUT= SHOULD HE FACILITY NEED TO BE RAINED 370 72.so' 370 ONTRA TOR SH ILL INS ALL A 0 M P A C ED CLAY CORE w/ A \ C TOFF T ENCH. MBANK k 4 ENT TO BE IN ACCORu NCE w THE DF SIGN SHOWN 0 THESE PLANS. STR:SWM MH 365 1 30" CL. III RCP MODIFIED VDOT MH-1 365 101.05 LF @ 8.41% TP=369.62 7\ INV IN: 364.00 TO 10 INV OUT: 360.00 TO WET P014D RISER FOUND TION TO REDUCE THE 1ISK OF FLOATAT 360 ON, RIS R BASE 360 & BARR L CONN CTION SHALL BE FIRMLY EMBEDDED CONCRETE 6" IN FOUN FO AN 1 ATION " THICK THAT IS I REINFORCED 'xW & BURIED \ OUTSIDE THE LIP IITS OF THE POOL ED WATER. 355 355 'so-10, 350 350 ss O 345 345 340 RIPRAP CHANNEL DESIGN RE QUIREMENTS: 340 STING GRADE. 2. CONY CTOR SHALL INS ALL A C SS II FIL ER FABR C UNDERLAYMENT MEETING MINI UM REQU REMENT SET FOR H IN TAB E 3.19-D OF THE ESCH STANDARD & SIDE _-IFICATIC N 3.19. F LTER FABRIC SHALL BE KEYED INTO TF E EXISTING GROUND A MIN MUM OFT' AT ITS ENDS & A ONG THE ENTIRE PERIMETER. 3. PLACEMENT OF =ILTER FABRIC SHAL BE DONE IMMEDIATELY AFTER SLOP 335 PREP RATION. EDGES OF THE FILTER SHEETS SHALL OVERLAP A LEAST 1 ". 335 FILTE . RIPRAP SHALL BE PLACED SO THAT IT PRODUCES A DENSE WELL -GRADED MASS OF STONE: WITH MINIMAL VOIDS. THE FINISHED SLOPE SF ALL BE FREE OF POCKETS OF SMALL STONE OR CLU TERS OF LARGE S ONES. D= i' Q,o 17.09 cfs 330 Vio 10.55 f S ' 1' 330 Dio= 0.71 FT RIPRA SWAL NO SCAL 325 PROPOSED V OT STD. CL. III IPRAP 325 4.25' THICKNE S WITH CLASS III FILTER FABRIP UNDE LAYMEN THAT 15 KEYED INTO THE EXISTING GROUND A Iv INIMUM OF 9" ALONG ITS ENTIRE PERIMETER 320 I I 320 315 315 312 312 > > O 0 L0 O 00 00 N N O 0-)CD Co O J J LLJ L d 00 4 ­t (6 O r.� � Cn 0i Ln Co Ln r- 00 00 r� 00 r� 00 r� I� r� CO r� Ln r� r� r7 N r7 r7 W LOi 0+50 1 +00 1 +50 2+00 2+50 3+00 3+50 PROFILE SCALES: WET ET POND SECTION 1"=50' (H) 4+00 4+50 5+00 5+25 LEVEL II WET POND DETAIL: SCALE 1 "=30' / 10' WIDE, 1' DEEP WE // \ ��,\ � IN GABION BASKETS PROPOSED SIGN, S \ /\ CONVEY 'GENERAL SWM NOTE' � / ­ OVERHEAD WETLAND CE #5 ON THIS SHEET CE T , EIR _ \ \ ELECTRIC LINES CREST L =3 9' J/ \ P SERVED TEE / LOPES, "T \ O �X" � 100-YEAR FLOODPLAIN / LIMITS, TYP. PROPOSED 10' WIDE TOP OF DAM ELEV.=384'. LEVEL TOP OF DAM TO SERVE / MAINTENANCE. / /\ \ ' / AS ACCESS FOR SWM ///�/ / 2' WIDE INTERIOR DAM C NSTRUCTED OF GABION BASKETS WIT STONE TO w CONVEY FLOWS TO MAIN ELL VIA 4 / J OVERTOPPING. TOP OF DAM LEV.=380', BOTTOM OF GABION BASK TS TO BE ANCHORED AT ELEV. 3 5.00 / TO REDUCE THE RISK OFF OATATION, RISER BASE & BARREL CONN CTION SH ILL BE FIRMLY EMBEDDED 6" I TO AN 18" - _TMP 07800-0 - O w J ON PLACE THICK REINFORCED CONCRETE FOUNDATION --- - THAT IS 8'x8' & BURIED OUTSIDE THE �� w - — WOBRELL _LAND_ �\ no V LIMITS OF THE POOLED WATER.00 --- —DEVELOPMENT COMPANY -LC— \ �.63-ate PROPOSED ESC 030" CL. III �'31 c o RCP BARREL -TO RE II�AIN. / PROPOSED VDOT STD. CL. -I1I\\�\�� / 3 00 RIPRAP (4.25' THICKNESS)-W_ _� CLASS- -FILTER FABRIC— ��� � 0 �UNDERLAYMENT THAT IS KEYE INTO THE EXISTING GROUND- MINIMUM OF 9" ALONG -ITS\ ----ENTIRE- PERIMETER J A CONTRALTO SHAL IN TAL' ALIFIED Ar 4+O I SHALL THEN INST LL NEW 0 O" CL. III RCP I I `� I I \� BARREL TO EXTEND TH OUTFAL BEYOND THE / I THE PROPOSED ESC UT L CONTRACTOR I \ / I i EXISTING J \ I I I I LIMITS OF TH EX STI G "WAY. I I I HEADWALL I I I I I I \ I I ARCEL LIMITS, I II I I I ( I I \ "� , MAI 4 o I C CEL -� N � P. I� I I � I \\ ��\ I ESC RISER FOUNDATION & LOWER PORTION OF ITS �. \ �_ p U o PE� 9VAC25-870-66 THE�LEV�L II WE POND \ 048" CL. III RCP STANDPIPE (ESC RIM ELEV.=381.25') \ C �� \ \ rV � o ll OUTF LL ANALYSIS ENDS AT THE FACILI DUE TO TO REMAIN. CONTRACTOR SHALL MODIFY THE TOP ' I I COMPLIANCE WITH THE 'ENE GY BA 'NCE \ \ \ \ PORTION OF THE ESC RISER TO HAVE VDOT MH-1 \\ 1 I CALCULATIONS 8e HAVING A POS�-DEVE�L PMENT \ UPPER CONE. CONTRACTOR SHALL INSTALL A \ I I I 10-YE R FLOW LESS THAN THE CORRESPONDING \ \ TRASHRACK OVER THE CONE's 024" OPENING 1 I I I 10-YEAR PRE-DEVELOPMEN FLAW. \ \ INSTEAD OF INSTALLING THE MH-1 FRAME &COVER. 9Z�i \ \ = \ \ I SWM FACILITY NEW RISER RIM ELEV.-381.75'. I i I 1 \ CONTRACTOR SHALL PLUG WATERTIGHT THE ESC � I \ \ ORIFICE & INSTALL ONE NEW 06" LOW -FLOW ORIFICE \\ 11 1 1 \ \ \I \ \ \ (INV.=380.00) WITH A TRASHRACK. 1 I 1 0 I \ \ I �. i �� \� \ \ \ l I I \ w \ \ \ \\ \ \ \ \ \ I I l l 10' WIDE, 1',A EEP WEIR 00 25 k:\ ' �?, 1 GABION B KETS TO CONVEY I I FLOWS TO MAIN CELL, W IR In I I � C EST ELEV.=3�' (� \ 1 \ \ \ PRESERVED STEEP / I I I I I / / P OPOSED 1: WIDE VDOT CL. A; \ \\\\\ \ SLOPES, TYP. / I I I / / I C-1, RIPRAP LINED EMERGENCY \ \ \ \ \ \ SP LLwAY CREST ELEVATION= 382.75'. \ \ \ \\ S ILLWAY TO HAVE 4:1 SIDE SLOPES / \ \ \ \ \ \ \ \ \ \ / / / L I I - \ / CONTRACTOR SHALL USE CO 0 UTRIENT RICH SOIL FOR THE 2N� AQUATIC BENCH & SHALL ENSURE I w / HEALTHY GROWTH OF PLANTINGS PROPOSED SIGN, DURING THE FIRST YEAR (TY .) SEE 'GENERAL I o MANAGED STEEP % WM NOTE' #5 ON I I I I I $LOPES, TYP. PROPOSED VAR. WIDTH THIS SHEET I I \I pRAINAGE' & SWM ESMT. — / I FEDERAL D%AM I c„ I I I I I I I I I I I INUNDATION OZONE, I �O \ TYP., o � SECTION A-9: TYPICAL GR PMCA-L DETAIL S - r-11 HgMp9twous fill 4' m'n I Cut off treneh—rrllobelol qdftblel Soil Dw rack L--___------j TYPICAL HOMOGENEOUS EMBANKMENT I Pipe outlet Coarse fikr Perforated aallctar oraurre s o F�undalton drain FOUNDATION DRAIN Sa k, Ord or rod. I ftm _-ft-ck too *Jrunakion filter CHIMNEY DRAIN Trom 6x ill ,,Rock or growel 9lanket drain BLANKET DRAIIN ��ck Of gravel lrairl Tmn�i#ion filter TOE DRAIN 5o�trce:.SC".SERVneeiing Fled Vaxrmai Figure A-Ia. Hopi ogeiicon s Fmhukmeim iri-Seepa e Conirolfs GENERAL SWM NOTES: 1. STATE APPROVED TRASH RACKS AND ORIFICES SHALL BE INSTALLED ON ALL ORIFICE OPENINGS. SEE DETAILS ON SHEET 8, OR EQUIVALENT. 2. CONCRETE FOUNDATIONS SHALL BE INSTALLED ON ALL RISER STRUCTURES MEETING MINIMUM VESCH 3.14 SPECIFICATIONS. 3. CONTRACTOR SHALL HIRE A THIRD PARTY GEOTECHNICAL ENGINEER TO ENSURE THE EMBANKMENTS ARE STRUCTURALLY SOUND. THE EMBANKMENTS SHALL HAVE A COMPACTED CLAY CORE WITH A CUTOFF TRENCH & BE IN ACCORDANCE WITH THE DETAILS SHOWN ON THIS PLAN. 4. THE DOWNSTREAM EMBANKMENT SIDE SLOPES OF ALL PERMANENT FACILITIES SHALL HAVE A MAXIMUM 3:1 SLOPE. 5. CONTRACTOR SHALL INSTALL TWO (2) SIGNS WITH PROMINENT LETTERS THAT ARE HIGHLY VISIBLE AND REFLECTIVE. THE LOCATIONS OF THE SIGNS ARE TO BE PLACED AT THE END OF THE RETAINING WALLS WHERE THE id WIDE DAM IS LOCATED, AS SHOWN, TO INCREASE PEDESTRIAN AWARENESS. SIGNS TO READ'WARNING / NO TRESPASSING'. WET POND DESIGN & REQUIREMENTS: Treatment Volume, TV (VRRM) 14,716 cf Minimum Treatment Volume Required for Level I I Basin 22,074 cf Treatment Volume Provided at MWSE 13,139 cf Minimum Percentage of TV Provided at MWSE 50 Percentage of TV Provided at MWSE 60 Ponding Depth Corresponding to Minimum TV Required 0.8 ft Maximum Ponding Depth allowed for Minimum TV 4 ft Maximum Percentage of Tv Provided above MWSE 50 Percentage of TV Provided above MWSE 40 Forebay Volume Required (0.25"/Imp. Ac.) 3,451 cf Forebay Volume Provided 6,348 cf Minimum Wetland Shelf Area (10% of Pond Area) 831 sf Upper Wetland Shelf Area Provided 878 sf PROPOSED 100' WIDE VDOT CL. Al, EC-1 RIPRAP LINED EMERGENCY SPILLWAY CREST ELEVATION= 382.75'. 385 SPILLWAY TO HAVE 4:1 SIDE SLOPES 385 380 380 100' PROPOSED GRAD XISTING GRADE 375 375 LLI W N O Ln Ln N O W W � O 4 N N N N O oo 00 00 00 00 wLi- r0 r7 r7 r7 0+50 1 +00 1 +25 WET POND SPILLWAY PROFILE SCALES: 1"=5' (V) 1"=5o' (H) AQUATIC BENCH (ZONE 1) PLANTING SCHEDULE FOR SWM FACILITY SYM BOTANICAL COMMON NAME SIZE SWM FACILITY QUANTITY COVERAGE (sf) ZONE 1 PLANTINGS PC PONTEDERIA PECTINATUS POND WEED - 1200 600 VA VALISNERIAAMERICANA WILD CELERY - 1388 925 EC ELODEA CANADENSIS WATERWEED - 1300 1,300 'DEEP\ 1f2tBAY � 1 LEVEL II WET POND LANDSCAPING DETAIL: SCALE 1 "=30' / ce 0 / / i I-- � i I I II I II SUBJECT PROPERTY,' TYP. I FEDERAL Dd INUITATI N Z NE, TY\ 1 10' WIDE, 12" DEEP AQUATIC BENCH PROPERTY LINE, TYP. , MANAGED STEEI SLOPES, AP. NADee RETAINING WALL NOTE: A it NO CANOPY OR UNDERSTORY TREES SHALL BE PLANTED WITHIN TEN (10) FEET OF THE BACK OF THE TOP OF THE RETAINING WALLS. ON I� O • N I �JL � 1•, i. OLL SCOTT J No. 35791 d 6/1/20 �4 IONAL 0 N N in w Q LO Zz O ¢ H w cl� m O Lu 0 J Z z Q O U >>~w LU LU a V) C g I I LU CD CD LU N N ro Q M rl U-11 C`7 N Uj CM Q I z N CD Q J N W Q � w I U0 J V)LU J z � � LU LLI L9 Q p I- C) Q O Q Q = U O w C LU ~ LU J U \W / � J W LU J �W Ld_/ �--� U) U) O w z O � IIIIII\ Qn V LU 0 LL ILL 0 Uj Q I.-�+ U LULU� _ a U) JOB NO. 172131 SCALE AS SHOWN SHEET NO. 7 DRY DETENTION CELL DETAIL; SCALE 1 "=30' ti ----- ' - 329.0' PROPOSED FLAT (0%) 18' LONG, 1.5' DEEP -- VDOT STD. CL. AI RIPRAP LINED OUTLET 3+39 PROTECTION.WIDTH AT PIPE OUT ALLO 110P SEE THIS _I / SHEET FOR ADDITIONAL NOTES & \ \ I \ / / INSTALLATION REQUIREMENTS. I / / / / � THE DRY DETENTION CELL IS IN-CORIPLIANCE WITH _ / / / \ MINIMUM 9VAC25-870-66 REGULATIONS. GHNNEL / PROTECTION IS MET VIA SUBSECTION B.3 ( NERGY- --- / / BALANCE CALCULATIONS). FLOOD PROTECTIO/N IS MET VIA \ SUBSECTION C.2.a (CONFINES THE POST-DEV. 10-yr FLOW 100-YEAR \ \ / z / WITHIN THE DETENTION CELL & RIPRAP CHANNEL-WITI -A FLOODPLAIN LIMITS OF ANALYSIS SET VIA SUBSECTION C.3.c \ Z ,(DISCHARGES TO A MAPPED FLOODPLAIN). � \ / ---- / / \ // ;i / --- PROPOSED OUTFALL SYSTEM, SEE \ \ \ \ \ \ \ \ \\ \ \ PROFILE ON THIS SHEET FOR DETAILS. STR CONTRACTOR SHALL INSTALL A VDOT MH-1 WITH A RIM ---- / x -- ELEVATION OF 3�3' 357.50'. A TRASHRACK SHALL BE INSTALLED OVER THE MH-1's UPPER 024" OPENING \ / ' INSTEAD OF A MH-1 FRAME & COVER. RISER TO ---- __- INVERT- 52.0 I 0 � LUDE A 2- LOW -FLOW ORIFICE WITH AN \ '. \ TO REDUCE THE RISK OF FLOAT�ON, \i/��,//�//� 3 0 / \ / RISER BASE & BARRELCONNECTION SHALL BE FIRMLY EMBEDDED S" ININT AN 18 - \. /K REINFORCED N RETE FOUNDATION CCO C 50' WIDE VDOT CL. Al, EC-1 RIPRAP / THAT IS 8'x8' & BURIED 0 SIDE THE LINED EMERGENCY SPILLWAY CREST -LIMITS6F - THE EXCA ATIOW STR 504 // � ELEVATION= 358.66'. SPILLWAY TO VAR.DTH HAVE 4:1 SIDE SLOPES DRAINAGE & SWM Z % APPROVED 10' WIDE TOP OF ESMT COINCIDES //%�- �� ° OF DAM TO SERVE AS ACCESS PR _ WITH PROPERTY LINE FOR SWM MAINTENANCE. RECORDED PUBLIC� APPROVED RIPRAP_ ` FACILITIES & ACCESS- LiN�00 EASEMENT FOR SWM DISSIPATER. �� A � DB 5276, PG 400-409) N CONTRACTOR SHALL EMOVE \ TO THE PUBLIC SEDIMENT LADEN MAT IAL F M- A � FAC TIES &ACCESS THE GEDIMENT ASIN & SHALL \ -REGRADE THE BASIN TO THE V V �c�\ \ EASEMEN�FOf2 SWf , PROPOSED CONTOUIRS SHORN- THILAN AT T TIMEOF THE FACILITY'S ONVERSION. Ct, v 3 648 AT THE TIME OF TEMPORARY SEDIMENT BASIN �\ #2's CONVERSION TO A PERMANENT SWM FACILITY, THE CONTRACTOR SHALL UNPLUG 0� `. \ THE LOW -FLOW ORIFICE, INSTALL THE �j `- \ V A 0, LOW -FLOW ORIFICE's TRASHRACK, REMOVE /// LL THE TEMP. 048" ESC TRASHRACK, INSTALL THE �j 9_/ �\ 47L� / UPPER SECTION OF THE MH-1 (FINAL RISER s� `- w RIM ELEV.=357.50), INSTALL THE PERMANENT 0 024" RISER TRASHRACK & PERMANENTLY PLUG / WATERTIGHT THE ESC DEWATERING ORIFICE / '78£ StormF axTMw ROUND SERIES TRASH RACK (OR EQUIVALENT) OONC RETE MANHOLE STANDARb60INCH RACKSHOVYN DIMENSIONS IN INGHES PLAN * CONTRACTOR SHALL INSTALL THE STORMRAX ROUND SERIES TRASHRACK WITH AN ANTI -VORTEX DEVICE, OR EQUIVALENT, TO ON THE RISERS FOR THE WET POND & THE DRY DETENTION CELL. ** CONTRACTOR SHALL INSTALL THE STORMRAX ROUND SERIES TRASHRACK WITH AN ANTI -VORTEX DEVICE, OR EQUIVALENT, ON THE TEMPORARY SEDIMENT BASIN's RISER H0PE9naUCrURA1 PLASnGUY PLASTIC WtUrVN S. IHC_ -~J I I rr{ w; I I it h 1 �4 SIDE VIEW StorrnRax"I Round Series forCcncrete Mlanhole Part No- Darn Aa Dim $ DFn'I C Min ID MI n DD RS-24 17 Y4 14 Y, 28 - 24 30 ks-16 21 14 4034 A 43 RS 4$ 27 19 54 . 49 57 RS-50 27 if A 34/1 66 % 60 70 Plastic Solutions, Inc. CWTOMER " PO Bax 43%. Wl nchestcr, VA 23604 23% hAcChae Rd, LWnfhesmr, VA Z2iO3 ,L&"i 8177-572.7 phormw. PM EC7: {5-00) 722- t9 fox httMjjw rw.plasifr_-_wWdm.0 n ❑LmTERSEcwh REMOVA LE FORAOCI= S ISDMETRI CONCRETE STRUCTURE DIMENI40NO I NSI DE STRUCTU RE DIMENSION OUTSIDE STRUCTURE 01MEN5ION AVArIUWLE OPTION$ CROSS 0RAC NG FOR OVERHANIC HDPE ANTI -VORTEX PLATE (REQ'D) DATE: PAW V. A FPD 6Y: DETAL'. APPROVED DRY DETENTION CELL CONSTRUCTION NOTES: FACILITY PLANTING SPECIFICATIONS: 1. THE DETENTION BASIN SHALL HAVE TURF GROUND COVER, SUCH AS GRASS, MULCH OR SOME OTHER FORM OF A VEGETATIVE GROUNDCOVER. LANDSCAPING BEYOND THIS IS OPTIONAL AND IS NOT REQUIRED. 2. THE PROPOSED SIDE SLOPES OF THE BASIN SHALL BE A MAXIMUM OF 4:1 TO REDUCE THE RISK OF EROSION. THE PROPOSED FLOOR SLOPES SHALL BE GRADED TO PROVIDE POSITIVE DRAINAGE AT ALL TIMES TO THE RISER STRUCTURE. 3. WOODY VEGETATION SHALL NOT BE PLANTED OR ALLOWED TO GROW WITHIN 15 FEET OF THE TOE OF THE EMBANKMENT NOR WITHIN 25 FEET OF THE PRINCIPAL SPILLWAY STRUCTURE. 4. A VEGETATED BUFFER SHALL BE PROVIDED THAT EXTENDS AT LEAST 20 FEET OUTWARD FROM THE BASIN TOP OF DAM ELEVATION. PERMANENT STRUCTURES (E.G., BUILDINGS, SHEDS, etc.) SHOULD NOT BE CONSTRUCTED WITHIN THE BUFFER AREA. EXISTING TREES SHALL BE PRESERVED IN THE BUFFER AREA DURING CONSTRUCTION IF AT ALL POSSIBLE. 5. THE SOILS IN THE STORMWATER BUFFER AREA ARE OFTEN SEVERELY COMPACTED DURING THE CONSTRUCTION PROCESS, TO ENSURE STABILITY THE DENSITY OF THESE COMPACTED SOILS CAN BE SO GREAT THAT IT EFFECTIVELY PREVENTS ROOT PENETRATION AND, THEREFORE, MAY LEAD TO PREMATURE MORTALITY OR LOSS OF VIGOR. AS A RULE OF THUMB, PLANTING HOLES SHOULD BE THREE TIMES DEEPER AND WIDER THAN THE DIAMETER OF THE ROOTBALL FOR BALL -AND -BURLAP STOCK, AND FIVE TIMES DEEPER AND WIDER FOR CONTAINER -GROWN STOCK. 6. AVOID SPECIES THAT REQUIRE FULL SHADE, OR ARE PRONE TO WIND DAMAGE. EXTRA MULCHING AROUND THE BASE OF TREES AND SHRUBS IS STRONGLY RECOMMENDED AS A MEANS OF CONSERVING MOISTURE AND SUPPRESSING WEEDS. CONTRACTOR REQUIREMENTS: 1. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS. 2. LANDSCAPE CONTRACTOR SHALL REFER TO THE STANDARDIZED LANDSCAPE SPECIFICATIONS FOR THE STATE OF VIRGINIA FOR ADDITIONAL INFORMATION. THE CONTRACTOR SHALL ABIDE BY ITS CONTENTS; HOWEVER ANY NOTES OR SPECIFICATIONS ON THE PLANS SHALL SUPERSEDE THOSE OUTLINED IN THE SPECIFICATIONS MANUAL COPIES ARE AVAILABLE FOR A FEE FROM THE VIRGINIA CHAPTER OF THE AMERICAN SOCIETY OF LANDSCAPE ARCHITECTS VIRGINIA NURSERYMEN'S ASSOCIATION INC. AND THE VIRGINIA SOCIETY OF LANDSCAPE DESIGNERS). 3. ALL PLANT MATERIAL SHALL MEET THE MINIMUM SPECIFICATIONS AND STANDARDS DESCRIBED IN THE CURRENT ISSUE OF THE AMERICAN STANDARD FOR NURSERY STOCK PUBLISHED BY THE AMERICAN ASSOCIATION OF NURSERYMEN 1250 STREET NW SUITE 500 WASHINGTON DC 20005. 4. THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE DESIGNER OF ANY VARIANCE FROM THE PLAN. 5. THE LANDSCAPE CONTRACTOR IS RESPONSIBLE FOR VERIFYING THE LOCATION OF ANY ONSITE UTILITIES (CALL MISS UTILITY 1-800-552-7001 BEFORE ANY EXCAVATION). 6. REFER TO THE APPROVED FINAL SITE PLANS FOR ANY DETAILED SITE INFORMATION. 7. ALL WORK SHALL BE COORDINATED WITH OTHER PARTIES. 8. PLANTS WILL BE PREPARED FOR SHIPMENT IN A MANNER THAT WILL NOT CAUSE DAMAGE TO THE BARK, BUDS, BRANCHES, STEMS, OR OVERALL SHAPE OF THE STOCK. CONTAINER GROWN PLANTS WILL BE TRANSPORTED IN THE CONTAINERS IN WHICH THEY HAVE GROWN. 9. ALL PLANT MATERIAL, UNLESS OTHERWISE SPECIFIED, SHALL BE UNIFORMLY BRANCHED AND HAVE A VIGOROUS ROOT SYSTEM. PLANT MATERIAL SHALL BE HEALTHY, VIGOROUS, AND FREE FROM DEFECTS, DECAY, DISEASES, INSECT PEST EGGS, AND ALL FORMS OF INFESTATION. ALL PLANT MATERIAL SHALL BE FRESH, FREE FROM TRANSPLANT SHOCK OR VISIBLE WILT. PLANTS DEEMED UNHEALTHY WILL BE REJECTED. 10. ALL CONTAINER STOCK SHALL HAVE BEEN PROPAGATED IN A CONTAINER LONG ENOUGH FOR THE ROOT SYSTEM TO HAVE DEVELOPED SUFFICIENTLY TO HOLD ITS SOIL. CONTAINER STOCK WITH POORLY DEVELOPED ROOT SYSTEMS WILL NOT BE ACCEPTED. 11. PLANTS NOT INSTALLED ON THE DAY OF ARRIVAL ON SITE SHALL BE STORED AND PROTECTED BY THE CONTAINER. OUTSIDE STORAGE AREAS WILL BE SHADED AND PROTECTED FROM THE WIND AND SUN. PLANTS STORED ON SITE SHALL BE PROTECTED FROM ANY DRYING AT ALL TIMES BY COVERING THE BALLS OR ROOTS WITH MOIST SAWDUST, WET BURLAP, WOOD CHIPS, SHREDDED BARK, PEAT MOSS, OR OTHER SIMILAR MULCHING MATERIAL. 12. THE OWNER RESERVES THE RIGHT TO SUBSTITUTE PLANT MATERIAL TYPE, SIZE AND/OR QUANTITY. ANY SUBSTITUTIONS MUST BE APPROVED BY THE INSPECTOR INITIALLY, AND THEN THE DESIGNER. 13. MINOR FIELD ADJUSTMENTS MAY BE NECESSARY DUE TO SITE CONDITIONS (EX: ROOTBALL AND UTILITY CONFLICT). MAJOR ADJUSTMENTS MUST BE APPROVED BY THE DESIGNER. 14. NO PLANTING SHALL OCCUR WHEN THE SOIL IS FROZEN. 15. PLANT MATERIAL SHALL BE PLACED IN EXISTING SOIL WITH EACH PLANTING PIT EXCAVATED TO A SIZE SUFFICIENT TO CONTAIN THE ENTIRE ROOT BALL OR ROOT MASS, WITHOUT CRAMPING ROOT STOCK. 16. THE CONTRACTOR SHALL MAINTAIN A ONE (1) CALENDAR YEAR 90% CARE AND REPLACEMENT WARRANTY FOR ALL PLANTINGS. THE PERIOD OF CARE AND REPLACEMENT SHALL BEGIN AFTER INSPECTION AND APPROVAL OF THE COMPLETE INSTALLATION OF ALL PLANTS AND CONTINUE FOR ONE CALENDAR YEAR. 17. THE CONTRACTOR IS RESPONSIBLE FOR REMOVAL AND DISPOSAL OF TRASH AND DEBRIS WITHIN THE LIMITS OF THE PLANTING ON A DAILY BASIS. 18. THE CONTRACTOR WILL NOT BE RESPONSIBLE FOR PLANT MATERIAL THAT HAS BEEN DAMAGED BY VANDALISM, FIRE, OR OTHER ACTIVITIES BEYOND THE CONTRACTOR's CONTROL. FACILITY CONSTRUCTION 1. THE DETENTION BASIN MAY SERVE AS A SEDIMENT BASIN AND/OR TRAP DURING PROJECT CONSTRUCTION. IF THIS IS DONE, THE VOLUME SHALL BE BASED ON THE MORE STRINGENT SIZING RULE (EROSION AND SEDIMENT CONTROL REQUIREMENTS VS. STORMWATER TREATMENT REQUIREMENTS). INSTALLATION OF THE PERMANENT RISER SHALL BE INITIATED DURING THE CONSTRUCTION PHASE, AND DESIGN ELEVATIONS SHALL BE SET WITH FINAL CLEANOUT OF THE SEDIMENT BASIN AND CONVERSION TO THE POST -CONSTRUCTION POND IN MIND. APPROPRIATE PROCEDURES SHALL BE IMPLEMENTED TO PREVENT DISCHARGE OF TURBULENT WATERS WHEN THE BASIN IS BEING CONVERTED INTO AN DETENTION BASIN. FOR THIS DESIGN IN PARTICULAR, THE RISER, RISER FOUNDATION, BARREL AND LOW -FLOW ORIFICE SHALL BE INSTALLED AT THE TIME OF THE SEDIMENTTRAP's CONSTRUCTION AND SHALL REMAIN WATERTIGHT UNTIL THE TRAP IS CONVERTED TO A PERMANENT FACILITY. 2. THE DETENTION BASIN SHALL ONLY BE CONSTRUCTED AFTER THE CONTRIBUTING DRAINAGE AREA TO THE POND IS COMPLETELY STABILIZED. IF THE PROPOSED POND SITE WILL BE USED AS A SEDIMENT TRAP OR BASIN DURING THE CONSTRUCTION PHASE, THEN THE FACILITY WILL BE DEWATERED, DREDGED AND RE -GRADED TO DESIGN DIMENSIONS AFTER THE ORIGINAL SITE CONSTRUCTION IS COMPLETE. 3. INSTALL E&S CONTROLS PRIOR TO CONSTRUCTION OF THE BASIN, INCLUDING TEMPORARY DE -WATERING DEVICES AND STORMWATER DIVERSION PRACTICES. ALL AREAS SURROUNDING THE BASIN THAT ARE GRADED OR DENUDED DURING CONSTRUCTION SHALL BE PLANTED WITH TURF GRASS, NATIVE PLANTINGS, OR OTHER APPROVED METHODS OF SOIL STABILIZATION. 4. CONTRACTOR SHALL EXCAVATE THE CORE TRENCH AND INSTALL THE SPILLWAY PIPE DURING THE ESC PHASE. 5. CONTRACTOR SHALL ALSO INSTALL THE RISER, OUTFLOW STRUCTURE AND/OR THE BARREL(s) DURING THE ESC PHASE TO ENSURE THE TOP INVERT OF THE OVERFLOW WEIR IS CONSTRUCTED LEVEL ATTHE DESIGN ELEVATION. 6. THE CONTRACTOR SHALL THEN CONSTRUCTTHE EMBANKMENT, AND ANY INTERNAL BERMS IF APPLICABLE, IN 8 TO 12-INCH LIFTS AND COMPACT THE LIFTS WITH APPROPRIATE EQUIPMENT. 7. UPON COMPLETION OF THE EMBANKMENT GRADING, THE CONTRACTOR SHALL EXCAVATE/GRADE UNTIL THE APPROPRIATE ELEVATION AND DESIRED CONTOURS ARE ACHIEVED FOR THE BOTTOM AND SIDE SLOPES OF THE BASIN. 8. CONTRACTOR SHALL THEN CONSTRUCT THE EMERGENCY SPILLWAY IN CUT OR STRUCTURALLY STABILIZED SOILS. 375 9. THE CONTRACTOR SHALL THEN FINISH CONSTRUCTION OF ALL OUTLET STRUCTURES, INCLUDING DOWNSTREAM RIP -RAP APRON PROTECTION. 10. THE CONTRACTOR SHALL NEXT STABILIZE EXPOSED SOILS BY HYDROSEEDING OR SEEDING OVER STRAW. 11. THE CONTRACTOR SHALL THEN INSTALL THE APPROPRIATE BASIN LANDSCAPING IN ACCORDANCE WITH THE APPROVED PLANS. FACILITY MAINTENANCE: MAINTENANCE OF THE DETENTION BASIN IS DRIVEN BY ANNUAL INSPECTIONS THAT EVALUATE THE CONDITION AND PERFORMANCE OF THE FACILITIES. DURING THESE INSPECTIONS THE FOLLOWING TASKS SHALL BE PERFORMED BY THE CONTRACTOR IN THE FIRST YEAR FOLLOWING INSTALLATION, AND THE OWNER THEREAFTER: 1. MEASURE SEDIMENT ACCUMULATION LEVELS IN THE BASIN. 2. MONITOR THE GROWTH OF THE GROUNDCOVER AND ANY TREES AND SHRUBS PLANTED, AS APPLICABLE. RECORD THE SPECIES AND THEIR APPROXIMATE COVERAGE AND NOTE THE PRESENCE OF ANY INVASIVE PLANT SPECIES, AS APPLICABLE. 3. INSPECT THE CONDITION OF STORMWATER INLETS TO THE BASIN FOR MATERIAL DAMAGE, EROSION OR UNDERCUTTING. 4. INSPECT THE BANKS OF UPSTREAM AND DOWNSTREAM CHANNELS FOR EVIDENCE OF SLOUGHING, ANIMAL BURROWS, BOGGY AREAS, WOODY GROWTH, OR GULLY EROSION THAT MAY UNDERMINE EMBANKMENT INTEGRITY. 5. INSPECT BASIN OUTFALL CHANNEL FOR EROSION, UNDERCUTTING, RIP -RAP DISPLACEMENT, WOODY GROWTH, etc. 6. INSPECT CONDITION OF PRINCIPAL SPILLWAY AND RISER FOR EVIDENCE OF SPALLING, JOINT FAILURE, LEAKAGE, CORROSION OR OTHER FAILURES. 7. INSPECT CONDITION OF ALL TRASH RACKS, REVERSE SLOPED PIPES OR FLASHBOARD RISERS FOR EVIDENCE OF CLOGGING, LEAKAGE, DEBRIS ACCUMULATION OR OTH FAILURES. 8. INSPECT MAINTENANCE ACCESS TO ENSURE IT IS FREE OF WOODY VEGETATION, AND CHECK TO SEE WHETHER VALVES, MANHOLES AND LOCKS CAN BE OPENED AN OPERATED. 9. INSPECT INTERNAL AND EXTERNAL SIDE SLOPES OF THE BASIN FOR EVIDENCE OF SPARSE VEGETATIVE COVER, EROSION, OR SLUMPING. 10. OWNER OR CONTRACTOR SHALL MAKE NEEDED REPAIRS IMMEDIATELY. FACILITY INSPECTION: MULTIPLE INSPECTIONS ARE CRITICAL TO ENSURE THE BASIN(s) ARE PROPERLY CONSTRUCTED. BECAUSE THE TIMING OF THE INSTALLATION IS DICTATED BY THE CONTRACTOR, THE CONTRACTOR SHALL BE RESPONSIBLE FOR CONTACTING THE ENGINEER AND INSPECTOR PRIOR TO INSTALLATION. MULTIPLE SITE VISITS AND INSPECTIONS ARE REQUIRED TO BE SCHEDULED BY THE CONTRACTOR WITH THE ENGINEER AND INSPECTOR DURING THE FOLLOWING STAGES OF THE DETENTION BASIN' CONSTRUCTION PROCESS: 1. PRE -CONSTRUCTION MEETING 2. INITIAL SITE PREPARATION (INCLUDING INSTALLATION OF PROJECT E&S CONTROLS) 3. EXCAVATION/GRADING (e.g., INTERIM/FINAL ELEVATIONS) 4. EXTENDED DETENTION BASIN INSTALLATION (e.g., INTERIM AND FINAL ELEVATIONS) 5. INSTALLATION OF THE EMBANKMENT, THE RISER/PRIMARY SPILLWAY, AND THE OUTLET STRUCTURE(s). 6. PLANTING PHASE (WITH AN EXPERIENCED LANDSCAPE ARCHITECT PRESENT/DIRECTING) 7. FINAL INSPECTION (DEVELOP A PUNCH LIST FOR FACILITY ACCEPTANCE) DRY DETENTION CELL SPILLWAY 50' WIDE VDOT CL. A: RIPRAP LINED EMERC SPILLWAY CREST ELEV 358.66'. SPILLWAY TO F SIDE SLOPES APPROVED 10' WIDE TOP 365 OF DAM ELEV.=360'. 365 PROPOS D 360 GRAD 360 o� 50 EC-1 ENCY NTION= 355 4GRADE XISTIN 355 AVE 4:1 350 350 J J N 0 N W W 0 Q0 0 W r7 Lei 0+50 0+75 PROFILE SCALES: 1"=5' M 1"=So'(H) RIPRAP LINED OUTLET PROTECTION DESIGN REQUIREMENTS: 1. RIPRAP LINED OUTLET PROTECTION SHALL BE INSTALLED IN CUT WITH CLASS II FILTER FABRIC UNDERLAYMENT LOCATED IMMEDIATELY UPLAND OF THE FLOODPLAIN. 2. OUTLET PROTECTION FOR THE DRY DETENTION CELL SHALL BE 15' LONG & BE FLAT WITH A 0% GRADE. WIDTH AT BEGINNING OF OUTLET PROTECTION=10', WIDTH AT END OF OUTLET PROTECTION=14'. 3. CONTRACTOR SHALL INSTALL A CLASS II FILTER FABRIC UNDERLAYMENT. FILTER FABRIC SHALL BE KEYED INTO THE EXISTING GROUND A MINIMUM OF 12" AT ITS ENDS & ALONG THE ENTIRE PERIMETER. 4. A 6" LAYER OF #57 STONE SHALL BE PLACED OVER THE FILTER FABRIC FOR ITS PROTECTION BEFORE THE VDOT STD. TYPE I RIPRAP IS INSTALLED. 5. PLACEMENT OF FILTER FABRIC SHALL BE DONE IMMEDIATELY AFTER OUTLET PROTECTION PREPARATION. EDGES OF THE FILTER SHEETS SHALL OVERLAP AT LEAST 9". 6. STONE PLACEMENT SHALL FOLLOW IMMEDIATELY AFTER PLACEMENT OF THE FILTER FABRIC & #57 STONE. RIPRAP SHALL BE PLACED SO THAT IT PRODUCES A DENSE WELL -GRADED MASS OF STONE WITH MINIMAL VOIDS. THE FINISHED SLOPE SHALL BE FREE OF POCKETS OF SMALL STONE OR CLUSTERS OF LARGE STONES. 7. OUTLET PROTECTION SHALL TIE INTO EXISTING GROUND IN CUT AT A MAXIMUM SLOPE OF 3:1. 8. CONTRACTOR SHALL SCHEDULE A MEETING WITH AN ENGINEERING DEPARTMENT INSPECTOR AT LEAST 24 HOURS IN ADVANCE OF THE OUTLET PROTECTION CONSTRUCTION. TICKETS FROM THE QUARRY SHALL BE AVAILABLE FOR REVIEW BEFORE STONE PLACEMENT TO ENSURE CORRECT STONE SIZES. STONE GRADATIONS SHALL MEET MINIMUM CURRENT VDOT ROAD AND BRIDGE SPECIFICATIONS. DRY DETENTION CELL SECTION 375 D DRY DE ENTION ELL RISER FOUNDATION NOTE: TO RED CE THE ISK OF FLOATATION, RISER BASE BARREL CONNEC ION SHALL BE FIRMLY EMBEDDED 6" INTO AN 18" THICK R INFORC D CONCRETE FOUNDATION THAT I 8'x8' & BURIED UTSIDE THE LIM TS OFT E EXCAVATION. 370 370 ' MH-1 WITH A IM ELEVATION OF 357.50' A TRASHRACK SHALL.BE INSTALLED MISTING OVER.THE MH 1's UPPER 024" PENING GRADE INSTEAD OF MH-1 FRAME & OVER. RISER TO INCLUDE A " 2-16' LOW -FLOW 365 ORIFICE WITH AN I VERT=3 2.00' 365 ER APPRO ED 10' IDE TOP OF DAM ELEV. 360'. 360 -PROPOSED GRADING ITH 360 MENDMENT. DRY 1 DETENTION C LL's VOLUME CONTRACTOR SHALL HAS BEEN ENLARGED. ��� INSTAL A CO PACTE s CLA CORE w/ A -Z- Q EMBANKMENT TO BE IN 7 � ACCO DANCE w/ THE 355 U) DESI N SHOWN ON 355 dPLAINS. Tr Ln BASIN BOTTOM SHALL HAVE POSITIVE SLOPE TO 350 THE RIS R IN AL PLACES 350 srR s 03 345 0 345 Ln PROPOSED 024" HOPE BARREL (64.63' @ 6.190 , INV. I =350.0 ', INV. OU =346.0 ') 340 CO TRACTOR TO I STALL 340 A " THICK STEEL PLATE AT THE BOTTOM OF THE MA HOLE S2� PROPOSED VD S °� STID. EW-1 IT 335 335 PROPOSED 024" HDPE ARREL (1 4.25' @ B.75%, INV. IN=33 .00', INV. OUT= 29.00') 330 330 PROPOSED FLAT (0%) 18' LONG, 1.5' DEEP VDOT STD. CL. AI RIPRAP INED OUTLET PROTECTION. WIDT AT FLOQDPLAIN=14', WIDTH AT PIPE OUTFALL=10'. 325 SEE THIS SHEET FOR ADD TIONAL NOTES & INSTALLATION REQUIREMENTS. 325 O O 0 O 0 r O- W W O ' c9 cD N LC) L6 Q0 r� CO CO '� r0 Ln W) W L_ 0+50 1 +00 1 +50 2+00 2+50 3+00 3+50 IS C OTT R. LLINS'Z �J No. 35791 1�0�Als��IOIVAL 6/1/20 �� E1SC'��� 0 N N Ln 0 w (� Q Zz � ¢ w Oa � � w m O U 0 VV) J Z z Q O U w W w V) Ce g 04 w rl 1 r � W C`7 ® 00 z N W M Q � z N O Uj Q J N N w Q � > cf) Ld � J J J V) Q U) z W W W 0 O � 0C J W J a V = Q z O U ■ ■ I � 0 o z LU '-' U) W � W ~ LJJ 0 U) Q W ~ LU ® U) O J W z � O J Q W 0 LL LL 0 N LU Q Z H LU cr Cl- w _ Un JOB NO. 172131 SCALE AS SHOWN SHEET NO. 8 LEVEL II BIORETENTION BASIN #1 DETAIL, SCALE 1"=20' P OPOSE _ \ - _ _�_ I I ILDIN 6 j BIOFI TER T AL I / PROPOSED PARKING LOT TO SERVE AS - - -" OPOS D STIR. 8 ° ACCESS TO BIORETENTION BASIN #1 / I B PROPOSED VDOT. STD. DI-1 WITH A RIM I ELEVATION (382.50') SET 6" ABOVE THE ° ° _ BIOFILTER PONOP SURFACE DING DEPTHS 380 60') TO oo w o _ PROPOSED 6" SCHEDULE 40 PVC PERFORATED I UNDERDRAINS TO OUTFALL INTO THE PROPOSE � 1 RISER STRUCTURE. PERFORATED UNDERDRAINS 01 I TO INCLUDE 4 SOLID CLEANOUTS. _I _ Ln I - II PROPOSED 5' WIDE PEA PROPOSED 15' WIDE PEA GRAVEL LINED FOREBAY I I N RISER I` 1 GRAVEL LINED EMERGENCY SPILLWAY CREST ELEVA ON SPILLWAY REST ELEV.-382.00 TO CONVEY C BOO I J. (382.50) SET 6 ABOVE THE RUNOFF FROM -THE FOREBAY TO THE BIOFILTER \ M I BIORLTER's TOP SURFA E OPOSED 1' WIDE FOREBAY INTERIM TOP / 39, -1 I (382.00') TO LIMIT PON3NG OF DAM :=383:00' \ ELEVi - M I DEPTHS TO 6„ PROPOSED PRE-TR ATMENT FOREBAY CELL \ RE IRED. PROPOSED) co �� 0+ 0 (151 cf 581 cf PROPOSED 08" ADS ROOF D IN (WITH END SECTION) D0 / TO OUTFALL INTO RAVEL FLOW SPREADER / �O / P OPOSED 1o' WIDE TOP PROPOSED PRE-TREATMENT GR EL FLOW SPREADER, SEE / ON TH\ SHEET. PROPO D DESIGN INCLUDES A / Q� /OF DAM ELEV-383.00' DETAIL i DEEP TRAPEZOtDA�L DITCH 'WIDE BOTTO /3:1 SIDE SLOPES) EXTENDING FROM THE OOF D"O THE SUMP's / BOTTOM. GRAVEL FLO EADER TO INCLUDE 12" EPRESSION/PLUNGE POOL. i PROPOSED PUBLIC FACILITIES & S�HOR ST FLOW PATH (45') / i' ACCESS EASEMENT FOR SWM 000 ❑ OVER -LENGTH (39') Z0.$ PROPOSED BIOFILTER FLOOR AREA ° i (607 sf REQUIRED, 640 sf PROPOSED) 3 8zTW-37,6BW PROPOSED BIOFILTER TOP SURFACE ELEVATION=382.00'. CONTRACTOR SHALL EXCAVATE VERTICALLY BENEATH THE BIOFILTER FLOOR TOP ELEVATION TO A DEPTH OF 4.5', OR ELEVATION 377.5'. CONTRACTOR SHALL / BACKFILL THIS AREA STARTING AT THE BOTTOM WITH 12" OF VDOT #57 / STONE. THE PROPOSED UNDERDRAINS SHALL BE PLACED INSIDE THE #57 PROPERTY STONE LAYER. THE CONTRACTOR SHALL INSTALL INSTALL A 3" DEEP LAYER / - LINE, TYP. OF PEA GRAVEL OVER THE #57 STONE BED, WITH A 4' WIDE FILTER FABRIC CENTERED ON THE UNDERDRAINS. A3' DEEP STATE -APPROVED BIOFILTER - MIX SHALL THEN BE PLACED ON TOP OF THE PEA GRAVEL. THE CONTRACTOR _ SHALL THEN INSTALL A 3" DEEP LAYER OF SHREDDED HARDWOOD MULCH. LEVEL II BIORETENTION BASIN #1 LANDSCAPING DETAIL, SCALE 1 "=20' FACILITY SIDE SLOPES SHALL I BE MULCHED WITH SWAMP I ° MILKWEED PLANTINGS, ° D TYPICAL. (300sf) .. :aQ.aUPFro, 0, t0 s ' .ram .. . -i • ..! i • i ..I,70.1 s �d 1 •� b 1 Q�� oo• o • BIORETENTION BASIN PROFILE NOTES: 1. PROPOSED BIOFILTER TOP SURFACE ELEVATION=382.00'. 2. CONTRACTOR SHALL EXCAVATE VERTICALLY BENEATH THE BIOFILTER FLOOR TOP ELEVATION TO A DEPTH OF 4.5', OR ELEVATION 377.50'. 3. CONTRACTOR SHALL BACKFILL THIS AREA STARTING AT THE BOTTOM WITH 12" OF VDOT #57 STONE. THE PROPOSED UNDERDRAINS SHALL BE PLACED INSIDE THE #57 STONE LAYER. THE UNDERDRAINS SHALL BE SLOPED TO DRAIN & DAYLIGHT TO THE RISER AND SHALL HAVE A 12" #57 STONE SUMP LOCATED BELOW THE INVERT OF THE UNDERDRAINS. 4. PROPOSED CLEANOUTS SHALL BE INSTALLED IN ACCORDANCE WITH THE DETAIL ON THIS SHEET. THE CLEANOUTS SHALL BE INSTALLED AT CRITICAL POINTS ALONG THE UNDERDRAIN SYSTEM & AT CHANGES IN DIRECTION OF THE PIPES. 5. THE CONTRACTOR SHALL INSTALL INSTALL A 3" DEEP LAYER OF PEA GRAVEL OVER THE #57 STONE BED, WITH A 4' WIDE FILTER FABRIC CENTERED ON THE UNDERDRAINS. 6. A 3' DEEP STATE -APPROVED BIOFILTER MIX SHALL THEN BE PLACED ON TOP OF THE PEA GRAVEL. 7. THE CONTRACTOR SHALL THEN INSTALL A 3" DEEP LAYER OF SHREDDED HARDWOOD MULCH. 8. THE PROPOSED ROOF DRAIN SYSTEM, TOTALING 253' OF PIPE ALONG THE NORTHERN SIDE OF BUILDING 6, WILL OUTFALL INTO THE BIORETENTION BASIN. THIS ROOF DRAIN SYSTEM IS A CLOSED -SYSTEM WITHOUT OPEN INLETS. THE SYSTEM WILL BE FED BY THE BUILDING's DOWNSPOUTS, AND WILL ORIGINATE WITH A 90° BEND AT BUILDING 6's NORTHERN CORNER (INVERT=383.77). THE ROOF DRAIN SYSTEM's OUTFALL INTO THE BIORETENTION BASIN HAS AN INVERT OF 382.5. PROPOSED VDOT. STD. DI-1 WITH A RIM ELEVATION (382.50') SET 6" ABOVE THE BIOFILTER's TOP SURFACE (382.00') TO LIMIT PONDING DEPTHS TO 6". PROPOSED 15' WIDE PEA GRAVEL LINED 0 PROFILE SCALES: FOREBAY SPILLWAY, CREST ELEV.=382.0' 00 1"=5' (V) (V WIDE INTERIM FOREBAY TOP OF DAM p 1"=5o' (H) ELEVATION=383.00') 0 U, > 00 rY O rn PEA GRAVEL STABILIZED SDILLVVAY DROP INLET WITH COMPACTED SOIL AROUND STRUCTURE STABI LIZED I NFLO VV INFLOVI/ PRETREATMENT 0" SCHD 4C PERFORATED UNDERDRAIN MODIFIED - Fr Figure 9-B.4. Typical 8raretenfrvn Basin Inflow & Outflow - Section (MODIFIED) 5 YP VA DCR STORMWATER DESIGN SPECIFICATION NO.9 REC)0Mh tAX0 3' pr7F[) HAFCPAK pO MULCH LAYIE R EX?RE T E N T" SM MEDIA iw+k111Fum 3M - - 3' 14NNLWW CHOKE A ST011IF LAYEFI 1 7'"1LTRATK:)N S,ILO1P (tLAl1+II1+AL1M) BELOW UNDEFCAAAN PROPOSED 28.75 LF OF 08" ADS ROOF 390 uJ Ln 390 RAIN @ 0.50% (II=382.64, I0=382.50). EXISTINIj 0N0 ROOF DRAIN TO INCLUDE END SECTION. \ rn O GRADE II CONTRACTOR SHALL INSTALL A PROPOSED ADS CLEANOUT \ z COMPACTED CLAY CORE w/ A 390 390 \ \ - -PROPOSED CUTOFF TRENCH. EMBANKMENT PROPOSED PRE-TREATMENT GRAVEL \ GRADE TO BE IN ACCORDANCE w/ THE FLOW SPREADER. PROPOSED DESIGN \ DESIGN SHOWN ON THESE PLANS. INCLUDES A 12" DEEP TRAPEZOIDAL 385 385 DITCH (2' WIDE BOTTOM w/ 3:1 SIDE 382.00' SLOPES) EXTENDING FROM THE ROOF DRAIN TO THE SUMP's BOTTOM. TOP SURFACE OF GRAVEL FLOW SPREADER TO INCLUDE \ BIOFILTER 12" DEPRESSION/PLUNGE POOL. \ 381.75' ry . \ BOTTOM OF MULCH PROPOSED PRE-TREATMENT O \ 80 3 FOREBAY CELL 378 75' STR:8o VDOT STD. DI-3C (L=6' BOTTOM OF BIOFILTER MIX - --- TP=384 50 378.5' INV IN: 378.3.o TO RISER 378 BOTTOM OF PEA GRAVEL INV OUT: 378.00 TO 78 PROPOSED 06" SCHEDULE 40 PVC 377.5' O ^ PROPOSED MIN. 5' WIDE PEA PERFORATED UNDERDRAINS 10' BOTTOM OF ^ O `� N BARREL GRAVEL LINED EMERGENCY O.C. WITH 04" NONPERFORATED #57 STONE 0 00 00 op 12" HDPE SPILLWAY CREST ELEV.38z.5o'. CLEANOUTS. SEE DETAIL ON THIS m m m 2. O LF 0.8$% SPILLWAY CREST ELEV. OF 382.50' 5 3 C SHEET. ESTABLISHES A MAXIMUM 6" I PONDING DEPTH. 0+50 1+00 BIORETENTION BASIN SECTION io'WIDE MIN. TOP O DAM ELEV.=3 3.00'. 385 385 M 5 38o 38o N O O 00 00 00 00 m m ENCFC_TEP4TK)N AREA MAXI ALIM BIORETENTION f'yr r FILTER FABRIC fPLA OF0 ON CI-ICKER ST(*& DYER Vx4DEFCPA11N ONLY, 1 - 2' TO ErTHW sM P'EFiFQFLATED PIPE I10 SPACE tAA30 Figure 9.4c: Typical Blorefentiort Basin Leve! 2: infiltration Sump PROPOSED GRADE -EXISTING GRADE 0+00 0+25 BIORETENTION BASIN SPILLWAY Figure-9-B,3. Bern) BIORETENTION BASIN CONSTRUCTION NOTES: , zH C� _ ? LEVEL II BIORETENTION BASIN #1 DESIGN &REQUIREMENTS: '� �� Treatment Volume (Per VRRM Calculations) 804 cf FACILITY PLANTING SPECIFICATIONS: O 1. ROOTSTOCK OF THE PLANT MATERIAL SHALL BE KEPT MOIST DURING TRANSPORT FROM THE SOURCE TO THE JOB SITE AND UNTIL PLANTED. Minimum Treatment Volume Required For Level II 1,005 cf 2• WALLS OF PLANTING PIT SHALL BE DUG SO THAT THEY ARE VERTICAL. . � 3. THE DIAMETER OF THE PLANTING PIT MUST BE A MINIMUM OF SIX INCHES (6") LARGER THAN THE DIAMETER OF THE BALL OF THE TREE. SCOTT RLLINS o FZ Minimu Foreba Volume Re wired 15%of TV 151 Cf 4. THE PLANTING PIT SHALL BE DEEP ENOUGH TO ALLOW 1/8OFTHE OVERALL DIMENSION OFTHE ROOT BALL TOBEABOVE GRADE.LOOSE SOIL ATTHE BOTTOM OFTHE NO. 35791 Y q ( ) PIT SHALL BE TAMPED BY HAND. FO rebay Vo I ume Provided 581 cf 5. THE APPROPRIATE AMOUNT OF FERTILIZER IS TO BE PLACE AT THE BOTTOM OF THE PIT (SEE BELOW FOR FERTILIZATION RATES). 6. THE PLANT SHALL BE REMOVED FROM THE CONTAINER AND PLACED IN THE PLANTING PIT BY LIFTING AND CARRYING THE PLANT BY ITS BALL (NEVER LIFT BY BRANCHES 6/5/20 * Minim m Surface Area Required (Tv/Storage e Depth) 607 sf ORTRUNK). ��� X1s� q ( g p ) 7. SET THE PLANT STRAIGHT AND IN THE CENTER OF THE PIT SO THAT APPROXIMATELY 1/8 OF THE DIAMETER OF THE ROOT BALL IS ABOVE THE FINAL GRADE. SSIONAL ��� Surface Area Provided 640 sf 8. BACKFILL PLANTING PIT WITH EXISTING SOIL. 9. MAKE SURE PLANT REMAINS STRAIGHT DURING BACKFILLING PROCEDURE. 10. NEVER COVER THE TOP OF THE BALL WITH SOIL. MOUNT SOIL AROUND THE EXPOSED BALL. Length of Shortest Flow Path 45 ft 11. TREES SHALL BE BRACED BY USING 2' BY 2' WHITE OAK STAKES, STAKES SHALL BE PLACED PARALLEL TO WALKWAYS AND BUILDINGS. STAKES ARE TO BE EQUALLY SPACED Overall Length 39 ft ON THE OUTSIDE OF THE TREE BALL. UTILIZING HOSE AND WIRE THE TREE IS TO BE BRACED BY THE STAKES. g 12. BECAUSE OF THE HIGH LEVELS OF NUTRIENTS IN STORMWATER RUNOFF TO BE TREATED, BIORETENTION BASIN PLANTS SHOULD NOT REQUIRE CHEMICAL Shortest Flow Path / Overall Length Ratio ( > 0.8) 1.2 FERTILIZATION. CONTRACTOR REQUIREMENTS:(SEEPLANTSCHEDULEFORSPECIFICPLANTSPECIES) * Area b se d off 3Mix at 25% porosity, 3" pea gravel at 2% porosity, 12" stone 1. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS. 2. LANDSCAPE CONTRACTOR SHALL REFER TO THE STANDARDIZED LANDSCAPE SPECIFICATIONS FOR THE STATE OF VIRGINIA FOR ADDITIONAL INFORMATION. THE at 40% porosity & 6" of ponding at 100% porosity. Area represents min. area CONTRACTOR SHALL ABIDE BY ITS CONTENTS; HOWEVER ANY NOTES OR SPECIFICATIONS ON THE PLANS SHALL SUPERSEDE THOSE OUTLINED IN THE SPECIFICATIONS associated with required Treatment Volume MANUAL (COPIES ARE AVAILABLE FOR A FEE FROM THE VIRGINIA CHAPTER OF THE AMERICAN SOCIETY OF LANDSCAPE ARCHITECTS, VIRGINIA NURSERYMEN's ASSOCIATION, INC. AND THE VIRGINIA SOCIETY OF LANDSCAPE DESIGNERS). 3. ALL PLANT MATERIAL SHALL MEET THE MINIMUM SPECIFICATIONS AND STANDARDS DESCRIBED IN THE CURRENT ISSUE OF THE AMERICAN STANDARD FOR NURSERY STORM ATER MANAGEMENT FACILITY GRADING STOCK, PUBLISHED BY THE AMERICAN ASSOCIATION OF NURSERYMEN, 1250 STREET, NW, SUITE 500, WASHINGTON, DC 20005. 0 4 THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE DESIGNER OF ANY VARIANCE FROM THE PLAN Elevatio (ft) Area of ri Forebay Contours (sf) Volume (cf) 377.5 - - 378 - - 379 - - 380 - - 381 49 0 382 288 152 383 587 581 Elevation (ft) Area of Bioretention Footprint (sf) Volume (cf) 377.5 640 0 378 640 320 379 640 960 380 640 1,600 381 640 2,240 382 640 2,880 383 988 3,688 5. THE LANDSCAPE CONTRACTOR IS RESPONSIBLE FOR VERIFYING THE LOCATION OF ANY ONSITE UTILITIES (CALL MISS UTILITY 1-800-552-7001 BEFORE ANY EXCAVATION). fV 6. REFER TO THE APPROVED FINAL SITE PLANS FOR ANY DETAILED SITE INFORMATION. LL 1 7. ALL WORK SHALL BE COORDINATED WITH OTHER PARTIES. 0 8. PLANTS WILL BE PREPARED FOR SHIPMENT IN A MANNER THAT WILL NOT CAUSE DAMAGE TO THE BARK, BUDS, BRANCHES, STEMS, OR OVERALL SHAPE OF THE STOCK. LU (n CONTAINER GROWN PLANTS WILL BE TRANSPORTED IN THE CONTAINERS IN WHICH THEY HAVE BEEN GROWN. LU 9. ALL PLANT MATERIAL, UNLESS OTHERWISE SPECIFIED, SHALL BE UNIFORMLY BRANCHED AND HAVE A VIGOROUS ROOT SYSTEM. PLANT MATERIAL SHALL BE HEALTHY, VIGOROUS, AND FREE FROM DEFECTS, DECAY, DISEASES, INSECT PEST EGGS, AND ALL FORMS OF INFESTATION. ALL PLANT MATERIAL SHALL BE FRESH, FREE FROM p TRANSPLANT SHOCK OR VISIBLE WILT. PLANTS DEEMED UNHEALTHY WILL BE REJECTED. 10. ALL CONTAINER STOCK SHALL HAVE BEEN PROPAGATED IN A CONTAINER LONG ENOUGH FOR THE ROOT SYSTEM TO HAVE DEVELOPED SUFFICIENTLY TO HOLD ITS SOIL. Q Q CONTAINER STOCK WITH POORLY DEVELOPED ROOT SYSTEMS WILL NOT BE ACCEPTED. 0 LU U (n 11. PLANTS NOT INSTALLED ON THE DAY OF ARRIVAL ON SITE SHALL BE STORED AND PROTECTED BY THE CONTAINER. OUTSIDE STORAGE AREAS WILL BE SHADED AND PROTECTED FROM THE WIND AND SUN. PLANTS STORED ON SITE SHALL BE PROTECTED FROM ANY DRYING AT ALL TIMES BY COVERING THE BALLS OR ROOTS WITH LU 01 MOIST SAWDUST, WET BURLAP, WOOD CHIPS, SHREDDED BARK, PEAT MOSS, OR OTHER SIMILAR MULCHING MATERIAL. U m z:) UO 12. THE OWNER RESERVES THE RIGHT TO SUBSTITUTE PLANT MATERIAL TYPE, SIZE AND/OR QUANTITY. ANY SUBSTITUTIONS MUST BE APPROVED BY THE DESIGNER & U0 } LULU COUNTY ENGINEER PRIOR TO INSTALLATION. 0 J Z 13. MINOR FIELD ADJUSTMENTS MAY BE NECESSARY DUE TO SITE CONDITIONS EX: ROOTBALL AND UTILITY CONFLICT). MAJOR ADJUSTMENTS MUST BE APPROVED BYTHE ( ) z Q � DESIGNER AND COUNTY ENGINEER PRIOR TO INSTALLATION. O U 14. NO PLANTING SHALL OCCUR WHEN THE SOIL IS FROZEN. 15. PLANT MATERIAL SHALL BE PLACED IN EXISTING SOIL WITH EACH PLANTING PIT EXCAVATED TO A SIZE SUFFICIENT TO CONTAIN THE ENTIRE ROOT BALL OR ROOT MASS, > OC m WITHOUT CRAMPING ROOTSTOCK. w a V) 0 16. THE CONTRACTOR SHALL MAINTAIN A ONE 1 CALENDAR YEAR 90/o CARE AND REPLACEMENT WARRANTY FOR ALL PLANTINGS. THE PERIOD OF CARE AND () z REPLACEMENT SHALL BEGIN AFTER INSPECTION AND APPROVAL OF THE COMPLETE INSTALLATION OF ALL PLANTS AND CONTINUE FOR ONE CALENDAR YEAR. W z Z Z a 17. THE CONTRACTOR IS RESPONSIBLE FOR REMOVAL AND DISPOSAL OF TRASH AND DEBRIS WITHIN THE LIMITS OF THE PLANTING ON A DAILY BASIS. • 18. THE CONTRACTOR WILL NOT BE RESPONSIBLE FOR PLANT MATERIAL THAT HAS BEEN DAMAGED BY VANDALISM, FIRE, OR OTHER ACTIVITIES BEYOND THE RSHALL. Landscaping General Notes THE CONTRACTOR 19. THE CONTRACTOR SHALL CONTACT THE COUNTY INSPECTOR AND COLLINS ENGINEERING 24 HOURS PRIOR TO BACKFILLING THE BIOFILTERS AND REQUEST ANLU INSPECTION AND APPROVAL OF THE UNDERDRAINS INSTALLATION AND THE SOIL MIX. 0- 0 U) a Landscape Specifications: 20. THE BIOFILTER PLANTING AREAS SHALL BE COVERED WITH HEAVY STRAW MULCH TO A DEPTH OF 3" IMMEDIATELY AFTER PLANTING. The following specifications are the minimum standards that are acceptable for the installation of the plant material: FACILITY CONSTRUCTION > LU 13� i. BIORETENTION AREAS SHALL BE FULLY PROTECTED BY SILT FENCE OR CONSTRUCTION FENCING, PARTICULARLY IF THEY WILL RELY ON INFILTRATION. IDEALLY, 1. The contractor Shall be responsible for adhering t0 the COriStruCtlori sequence outlined on this page for the installation Of the bloreteritlori baSlri BIORETENTION SHALL REMAIN OUTSIDE THE LIMIT OF DISTURBANCE DURING CONSTRUCTION TO PREVENT SOIL COMPACTION BY HEAVY EQUIPMENT. landscaping. The Contractor shall also be responsible for locating all existing underground utilities prior to beglrimrig construction. Any planting BIORETENTION BASIN LOCATIONS MAY BE USED AS SMALL SEDIMENT TRAPS OR BASINS DURING CONSTRUCTION THOUGH. IF THE FACILITY IS USED AS A conflict arlSlri from eXlStlri Uhh locations Shall be brought t0 the atterihori Of the Owner. SEDIMENT TRAP OR BASIN, THE BIORETENTION BASIN MUST CONTAIN AN UNDERDRAIN. THE FACILITY MUST ALSO BE CLEANED FREE OF DEBRIS, STABILIZED g g Ty g AND ANY STRUCTURES PROPOSED TO REMAIN, REMOVED OR CONVERTED MUST BE DETAILED OR DISCUSSED ON THE PLANS. 2. The Contractor shall be responsible for providing positive drainage at 2% minimum in all planted areas. 2. CONSTRUCTION OF THE BIORETENTION AREA MAY ONLY BEGIN AFTER THE ENTIRE CONTRIBUTING DRAINAGE AREA HAS BEEN STABILIZED WITH VEGETATION. IT MAY BE NECESSARY TO BLOCK CERTAIN CURB OR OTHER INLETS WHILE THE BIORETENTION AREA IS BEING CONSTRUCTED. THE PROPOSED SITE SHALL BE 3. The Contractor shall verify plant count from the plan, and shall provide and install all plant materials shown on the approved plan. The plant CHECKED FOR EXISTING UTILITIES PRIOR TO ANY EXCAVATION. 3. THE DESIGNER AND THE INSTALLER SHALL HAVE A PRE -CONSTRUCTION MEETING, CHECKING THE BOUNDARIES OF THE CONTRIBUTING DRAINAGE AREA AND schedule provided is for the Contractor's reference only; quantities shall be Verified from the approved plan. THE ACTUAL INLET ELEVATIONS TO ENSURE THEY CONFORM TO THE ORIGINAL DESIGN. BECAUSE THE TIMING OF THE INSTALLATION IS DICTATED BY THE 4. The Contractor Shall guarantee all rant materials for I year from the date Of laritlri CONTRACTOR, THE CONTRACTOR SHALL BE RESPONSIBLE FOR CONTACTING THE ENGINEER. SINCE OTHER CONTRACTORS MAY BE RESPONSIBLE FOR P Y planting. CONSTRUCTING PORTIONS OF THE SITE, IT IS QUITE COMMON TO FIND SUBTLE DIFFERENCES IN SITE GRADING, DRAINAGE AND PAVING ELEVATIONS THAT CAN 5. The Owner or his designated agent shall approve any changes lri larit material with r10Y approval from County Engineering. PRODUCE HYDRAULICALLY IMPORTANT DIFFERENCES FOR THE PROPOSED BIORETENTION. THE GENERAL CONTRACTOR SHALL CLEARLY COMMUNICATE, IN g pp Yp p pp ty g g WRITING, ANY PROJECT CHANGES DETERMINED DURING THE PRE -CONSTRUCTION MEETING TO THE INSTALLER AND THE PLAN REVIEW/INSPECTION AUTHORITY. TEMPORARY E&S CONTROLS ARE NEEDED DURING CONSTRUCTION OFTHE BIORETENTION AREA TO DIVERT STORMWATER AWAY FROM THE BIORETENTION 6. All plant material shall be balled and burlapped or container grown and shall be well formed, V1gOrOUS, grOWlrig Specimens with growth typical 4. AREA UNTIL IT IS COMPLETED. SPECIAL PROTECTION MEASURES SUCH AS EROSION CONTROL FABRICS MAY BE NEEDED TO PROTECT VULNERABLE SIDE SLOPES of the variety Specified and free from injurious insects and diseases. FROM EROSION DURING THE CONSTRUCTION PROCESS. 5. ANY PRE-TREATMENT CELLS SHALL BE EXCAVATED FIRSTAND THEN SEALED TO TRAP SEDIMENTS. 7. All trees and shrubs shall be installed as indicated on the approved landscape plan. 6. EXCAVATORS OR BACKHOES SHALL WORK FROM THE SIDES TO EXCAVATE THE BIORETENTION AREATO ITS APPROPRIATE DESIGN DEPTH AND DIMENSIONS. LU Q 0 O N c 1 CD _q CD I j EXCAVATING EQUIPMENT SHALL HAVE SCOOPS WITH ADEQUATE REACH SO THEY DO NOT HAVE TO SIT INSIDE THE FOOTPRINT OFTHE BIORETENTION AREA. VA DEQ STORMWATER DESIGN SPECIFICATION NO.9 BIORETENTION PIPE FLOW i suaaRADE_ ~� 7 0RAVEL PI, r-1RAC3M -- - -� - LEVEL FAF)FR I FILTER FABRIC SECTION A -A 12' 8' CONCENTRATED FLOW PRETREATMENT - GRAVEL FLAN SPREADER NIS (Modified) Figlir e 9.9. Pre -Treatment ent - Grp ivl Flow Spreader for t~'anceittrated Floiv WATERTIGHT CAP ON TERMINAL END OF PIPE 4' P-V.O- SCREW CAP ON GRADE 4' P-V- . N0NPERF0RA7En STANDPIPE Figure 9-B. ?. 4" P. V.C. Cleanout Detail CONTRACTORS SHALL USE A CELL CONSTRUCTION APPROACH IN LARGER BIORETENTION BASINS, WHEREBY THE BASIN IS SPLIT INTO Soo TO 1,000 SO. FT. TEMPORARY CELLS WITH A io-iS FOOT EARTH BRIDGE IN BETWEEN, SO THAT CELLS CAN BE EXCAVATED FROM THE SIDE. 7. IT MAYBE NECESSARY TO RIP THE BOTTOM SOILS TO A DEPTH OF 6 TO 12 INCHES TO PROMOTE GREATER INFILTRATION. THIS REQUIREMENT WILL BE DICTATED BY THE INSPECTOR, PRIOR TO INSTALLATION OF THE REMAINDER OF THE FACILITY. 8. PLACE GEOTEXTILE FABRIC ON THE SIDES OF THE BIORETENTION AREA WITH A 6-INCH OVERLAP ON THE SIDES. IF A STONE STORAGE LAYER WILL BE USED, PLACE THE APPROPRIATE DEPTH OF #57 STONE ON THE BOTTOM, INSTALL THE PERFORATED UNDERDRAIN PIPE, PACK #57 STONE TO3INCHES ABOVE THE UNDERDRAIN PIPE, AND ADD APPROXIMATELY 3 INCHES OF CHOKER STONE/PEA GRAVEL AS A FILTER BETWEEN THE UNDERDRAIN AND THE SOIL MEDIA LAYER. IF NO STONE STORAGE LAYER Is USED, START WITH 6 INCHES OF #57 STONE ON THE BOTTOM, AND PROCEED WITH THE LAYERING AS DESCRIBED ABOVE. 9. DELIVER THE SOIL MEDIA FROM AN APPROVED VENDOR, AND STORE IT ON AN ADJACENT IMPERVIOUS AREA OR PLASTIC SHEETING. APPLY THE MEDIA IN 12-INCH LIFTS UNTIL THE DESIRED TOP ELEVATION OF THE BIORETENTION AREA IS ACHIEVED. WAIT A FEW DAYS TO CHECK FOR SETTLEMENT, AND ADD ADDITIONAL MEDIA, AS NEEDED, TO ACHIEVE THE DESIGN ELEVATION. I` io. PREPARE PLANTING HOLES FOR ANY TREES AND SHRUBS, INSTALL THE VEGETATION, AND WATER ACCORDINGLY. INSTALL ANY TEMPORARY IRRIGATION AS NEEDED. (� ii. PLACE THE SURFACE COVER IN BOTH CELLS (MULCH, RIVER STONE, PEA GRAVEL OR TURF), DEPENDING ON THE DESIGN. IF COIR OR JUTE MATTING WILL BE USED - IN LIEU OF MULCH, THE MATTING WILL NEED TO BE INSTALLED PRIOR TO PLANTING (STEP 9), AND HOLES OR SLITS WILL HAVE TO BE CUT IN THE MATTING TO INSTALL THE PLANTS. 12. INSTALL THE PLANT MATERIALS AS SHOWN IN THE LANDSCAPING PLAN, AND WATER THEM DURING WEEKS OF NO RAIN FOR THE FIRST TWO MONTHS. N 13. CONDUCT THE FINAL CONSTRUCTION INSPECTION. THEN LOG THE GPS COORDINATES FOR EACH BIORETENTION FACILITY AND SUBMIT THEM FOR ENTRY INTO THE LOCAL MAINTENANCE TRACKING DATABASE. M FACILITY MAINTENANCE: THE FOLLOWING TASKS SHALL BE PERFORMED BY THE CONTRACTOR IN THE FIRST YEAR FOLLOWING INSTALLATION: 1. FOR THE FIRST 6 MONTHS FOLLOWING CONSTRUCTION, THE SITE SHALL BE INSPECTED BY THE CONTRACTOR AT LEAST TWICE AND AFTER STORM EVENTS THAT EXCEED 1/2 INCH OF RAINFALL. N 2. THE CONTRACTOR SHALL LOOK FOR BARE OR ERODING AREAS IN THE CONTRIBUTING DRAINAGE AREA OR AROUND THE BIORETENTION AREA, AND MAKE SURE 0 THEY ARE IMMEDIATELY STABILIZED WITH GRASS COVER. CONTRACTOR SHALL SPOT RESEED AS NECESSARY. 3. ONE-TIME, SPOT FERTILIZATION MAY BE NEEDED FOR INITIAL PLANTINGS. ^' ` V 4. WATERING IS NEEDED ONCE A WEEK DURING THE FIRST 2 MONTHS, AND THEN AS NEEDED DURING THE FIRST GROWING SEASON (APRIL-OCTOBER), DEPENDING N ON RAINFALL. 5. REMOVE AND REPLACE DEAD PLANTS. SINCE UP TO io%OF THE PLANT STOCK MAY DIE OFF IN THE FIRSTYEAR, THE CONTRACTOR SHALL BE RESPONSIBLE FOR THE CARE AND REPLACEMENT WARRANTYTO ENSURE THAT VEGETATION IS PROPERLY ESTABLISHED AND SURVIVES DURING THE FIRST GROWING SEASON FOLLOWING CONSTRUCTION. THE TYPICAL THRESHOLDS BELOW WHICH REPLACEMENT IS REQUIRED ARE 9o%SURVIVAL of PLANT MATERIAL AND i00% SURVIVAL OF TREES. 6. A SPRING MAINTENANCE INSPECTION AND CLEANUP SHALL BE CONDUCTED AT EACH BIORETENTION AREA. THE FOLLOWING IS A LIST OF SOME OF THE KEY MAINTENANCE PROBLEMS TO LOOK FOR: Ld A. CHECK TO SEE IF75%TO 9o%COVER (MULCH PLUS VEGETATIVE COVER) HAS BEEN ACHIEVED IN THE BED, AND MEASURE THE DEPTH OF THE REMAINING MULCH. __J B. CHECK FOR SEDIMENT BUILDUP AT CURB CUTS, GRAVEL DIAPHRAGMS OR PAVEMENT EDGES THAT PREVENTS FLOW FROM GETTING INTO THE BED, AND �� J CHECK FOR OTHER SIGNS OF BYPASSING. C. CHECK FOR ANY WINTER- OR SALT -KILLED VEGETATION, AND REPLACE IT WITH HARDIER SPECIES. D. NOTE PRESENCE OF ACCUMULATED SAND, SEDIMENT AND TRASH IN THE PRE-TREATMENT CELL OR FILTER BEDS, AND REMOVE IT. ' )^ E. INSPECT BIORETENTION SIDE SLOPES AND GRASS FILTER STRIPS FOR EVIDENCE OF ANY RILL OR GULLY EROSION, AND REPAIR IT. �/ F. CHECK THE BIORETENTION BED FOR EVIDENCE OF MULCH FLOTATION, EXCESSIVE PONDING, DEAD PLANTS OR CONCENTRATED FLOWS, AND TAKE W APPROPRIATE REMEDIAL ACTION. G. CHECK INFLOW POINTS FOR CLOGGING, AND REMOVE ANY SEDIMENT. H. LOOK FOR ANY BARE SOIL OR SEDIMENT SOURCES IN THE CONTRIBUTING DRAINAGE AREA, AND STABILIZE THEM IMMEDIATELY. I. CHECK FOR CLOGGED OR SLOW -DRAINING SOIL MEDIA, A CRUST FORMED ON THE TOP LAYER, INAPPROPRIATE SOIL MEDIA, OR OTHER CAUSES OF O INSUFFICIENT FILTERING TIME, AND RESTORE PROPER FILTRATION CHARACTERISTICS. 1. FOR A LIST OF THE OWNER'S ANNUAL LONG-TERM MAINTENANCE ACTIVITIES AFTER THE CONTRACTOR's RESPONSIBILITIES HAVE BEEN COMPLETED, J PLEASE SEE BELOW. Annual Maintenance Activities for Braretention Maintenance Tasks Frequency • blowing of grass filter strips and bioretention turf cover At least 4 times a year • Spat weeding, erosion repair, trash removal, and mulch raking Twice during growing season • Add reinforcement planting to maintain desired the vegetation density As needed • Remove invasive plants using recommended control methods • Stabilize the contributing drainage area to prevent erasion • Spring inspection and cleanup • Supplement mulch to maintain a 3 inch layer Annually • Prune trees and shrubs • Remove sediment in pre-treatment cells and inflow paints Onre every 2 to 3 years • Replace the mulch layer Every 3 years FACILITY INSPECTION: CONSTRUCTION INSPECTIONS ARE CRITICAL TO ENSURE THE BIORETENTION BASINS ARE PROPERLY CONSTRUCTED AND ESTABLISHED. BECAUSE THE TIMING OF THE INSTALLATION IS DICTATED BY THE CONTRACTOR, THE CONTRACTOR SHALL BE RESPONSIBLE FOR CONTACTING THE ENGINEER AND INSPECTOR PRIOR TO INSTALLATION. MULTIPLE SITE VISITS AND INSPECTIONS ARE REQUIRED TO BE SCHEDULED BY THE CONTRACTOR, WITH THE ENGINEER AND INSPECTOR, DURING THE FOLLOWING STAGES OF THE BIOFILTER CONSTRUCTION PROCESS: 1. PRE -CONSTRUCTION MEETING 2. INITIAL SITE PREPARATION (INCLUDING INSTALLATION OF PROJECT E&S CONTROLS) 3. EXCAVATION/GRADING (E.G., INTERIM/FINAL ELEVATIONS) 4. BIOFILTER INSTALLATION (E.G., MICROTOPOGRAPHY, SOIL AMENDMENTS, STONE BEDDING, UNDERDRAINS AND STAKING OF PLANTING ZONES) S. PLANTING PHASE (WITH AN EXPERIENCED LANDSCAPE ARCHITECT PRESENT) 6. FINAL INSPECTION (DEVELOP A PUNCH LIST FOR FACILITY ACCEPTANCE) PLEASE ALSO SEE ABOVE, UNDER FACILITY MAINTENANCE #6, FOR REQUIRED INSPECTIONS. BIORETENTION BASIN LANDSCAPING SCHEDULE SYM BOTANICAL COMMON NAME SIZE SWM FACILITY QUANTITY COVERAGE (sf) Sc SCIRPUS CYPERINUS WOOLGRASS - 50 Ibs of seed 40 At ASCLEPIAS INCARNATA SWAMP MILKWEED - 100 Ibs of seed 330 PV PANICUM VIRGATUM SWITCHGRASS 50 Ibs of seed 40 SHRUBS MC MYRICA CERIFERA WAX MYRTLE 2-1/2" CAL. 1 - IG ILEXGLABRA INKBERRY 2-1/2" CAL. 2 - T REES BN BETULA NIGRA RIVER BIRCH 2" CAL. 1 AR ACER RUBRUM RED MAPLE 2-1/2" CAL. 1 - LS LIQUIDAMBAR STYRACIFLUA SWEETGUM 1-1/2" CAL. 1 - Zw w Jw J� u T_1 z LU 0 LU z Q C- Lr) ��G J 1 w U) 0 z z LU U) Q z 0 Q I- C) z 0 F___ I� LL] LU I� O IW Q J ^� LL 1 2 z 0 LL LU LL LU L"1 LU Q Z H w LU a JOB NO. 172131 SCALE AS SHOWN SHEET NO. 8A APPROVED WET POND CONSTRUCTION NOTES: .AIR FLO 3 DIFFUSED AERATION 5YSTEM SPECIFICATIONS PURPOSE: The di ffuse,d air, a*ratfan mi nuFacturer shall rovicie an underwater aerations slerrl dei- rytd toA@lam, �rwat � de-strati:N. and clrculaie water without d;lstuUng the natural surroundings o-f the lake ierlvirwMerrl. SCOPE: The diffused air, aera.tlon par+rkage shall be c4pa1plg 9f b-2ing installed in lakes deeper than 3fC (tor). PACKAGR This. miration package shall include the fallo'1't'ing equipmtnt: a.. ALircompressor cabinet end-asure.To Include corn InTessor(&), or€uIt dlsconrita, and air t1low apjgnping Yalvq Fngnifi2los_ To be dIE5iq ned to DpLrate qn eight r: L 6CHt paver, 11 5/20812310 Volt, 51n9le phase II. MHz power, 2 ?0/240 dolt, singre Rha€e • b_ Airj�xrgell dlsK diffuser maniioGd s e_ Tubing - •r 'Si - :. - .r " 0JL - e WW4T,�19ert}In$,C4R�a11114� I,if�ndeleilS C-kBI NEWINCLOSURE TUBING: WoRobl•e irr Td60 (3OW rxCr¢.ararr(S� C) 1 Compre€;~or Total required tubing far system= iD 2 Compressor __ Fleet ( m) Nonaveighted polyvinyl chloride tubing SPECIFY; 115 - Vents 60 Hz ______ Net ( m) Weighted patyethytene €hl- ride toWng DIFFUSER MANIFOLD(5): JE+ugfa ew UeurlAmj Tubing lerl gths pdr d ifhJ2W roamIfoId: Qubritit'y Type -_ Single DMManifuld(s) �-- y� W (D feet 0 meters) Non-weighte d tubing ,. Dual DISC hlaplfold(s) Q) feet {0 meters)Weighttdtubing PISTON AIR COMPRESSOR: (for lakes aft (1 m) deep or larger) The air compressar(s) shall be a 1/2HP rp1;lcing piston.dual frequency, permanent Split capadii; rip5c) elettricmDWrwith 4illess luhrication.direcr drive (no belts ar pul16A1, dl@M46ed f6e field St ACA e-apability. palyurkharte rust pr&ectlots, and do Inc6de the fan mviiing motor protectlon- thermal overload prateciloai, and intake al r filler. The 5ervireable parts_ piston [ups, rMiner screws, cylinder o-rings, head p-rings, valve an-d vatoe retainers: 3hftld last two years in cont111uous• ration, These In drllename parts shall be replaceable writh•c;ornmontool s. Please comuItyNrlocal distributor if you requilre assistant in choosing sizes, acca55,aries, or applications. JUR OaMPFESSOR CAMET ENCLOSURE: a. Cabinet body and cai-er c w&tructlon shall ht 18 gauge (0-0Qini/0.122prn) 3" stain less Steal, and I nclude EPDM edg"rip wal bo, CagimQt WQ1ing sy 5�tem to cons 2510 tw:o C2) axLal exhaus( fans and vexed intake louvers oni the bottorn of the c lainet to Rrovjde an air exchange r-am of 410-490 crkt c. Compressor-Irrtake air to be quick c han ge cut ridge type Alters d, Cabinet enclosure secured by stainless steel latch to accvmcdare ID&Ing merinanlsm Air Fla 3 8ilrusedAir System Speaficariws M Page 1 cf 2 AF - 4 ; P/N 03-3242 OR APPROVED EQUAL AAR/iOXYC,EN DIFFUSER MANIFQLE& The Edr/axygertt disr diffusers sl&ll include, but not be limited to. time following mdtedal5 of onnsau€dorr a_ Dist type 12in (# 50r1nrn} membrane diffusers allow For maxlrmum 1 2CFM and are resistant to -Ozone and UV L}. Membrane material ro be premium quality compression molded EPZ44 with an all content of 1le5s than« 1 2% i rrn mixanes should haves minimum of 101SS silt erforatlonsand be at least 70%h dro ills r, Diffuse e p w pll with temslle strength at 2000 psi d , IDlffusex w consist of membrane with i ntegral gasket, base, retaining ring,, and air flaw contrlSl irifice e, membrane shal l col lapse and s4al wtl en ;iemti*n vystem air is turned OFf FL Sealing methad of returning dq*n shall generate a minimum of 54 pounds per inch/53 K21CIM 4F circumFerence of the seallnz9 Bask -et ro provide a lone term poslirve seal and to prevent air escape g, 01ffuser base and retain log ring (0te cernstructed of Klyprupytent withwg;ink UV stablair:en and a tensile strength of 5000 psi h, Diffuse rto- Jhave one 314irLV_5(m)conn-�crlanmerhadtomanifold I, Each diffuserrAhaII iitdude ELmanilvIdthatwi11 icon ntct up to tl+iio Q) alr-distlr to the al supply tuhln-9 j. Manifold base shall N! cimstru cted of high -density polyethylene pl�isticand Incorporate ball astcha,renel-5 for ICI sinking -of Raft firing in*talla M I i WEIGHTED P�0'L'�L+INYL CHLORIDE TIJBIIVC� Tubing ;~ha l b� carls4ru€ked of f7earus+, n'eg�aitlYe buoyancy, iPaIS+Fr rnrl chloride (PVC) materkal. The FVC tubing shall he 112' (1 tn1) writ a rnin11nu1n wall lhitkrIMS of 1/4" (.64 CM). Pressure rating Aall he 225 psi at 70a F (21 o C7 Coll lengths Shall be 100' (30 rn), with a weight per 100' 00 rn) of 43;lbs (20 kg), Tabeng shall b-e 5elf-5iriking, lead freer and cpFsLain €arh¢n black for LlV pratenion. PleasI! WinsaIt your kwal distributor for addlrloral Information. NON•1YEIGHTED POLY ETHYLENE TUBIN15, The polyethylene tubing shaalI he 1/21n (Icrn)with a rnlnkmLim wall ihitkrtessof.D6in v.3mrn)r Pressurt rating shall be 10ip5i-at 23 P (22 Q, C.01 Iengths shall be 10O' (39 n),Zyikh a weight per 100k (30rrt)of 11 Ihs (5 kg}_ Tubing shall contain 2%carbon black Fro, long term L;V protectlun. (*lease consult your local distrib'utorfor add ltlonal information, INSERT FfFTING*h- Insert frtJtings are used Lo repair, adapt, or connect with the Klytthylene WbIng, rit#ie194 available shall In€l ude Iipe size couplings, male adapters, and elbaw5_ TFiTING: A. Safety - The orator s_ystern shall be tested and appro+red as a unit. Separate d]IjlTlpOnent testing Flat aLloned, Unit must b-ete5ted byrEn, En-C, CE� UL or�xher accredlied testing facihcle5. 6. PerFar171MCe - Lin Itrnust heave In(igpend-Ent perfprrtlaelci� tes-ting prrnrldied by, G5EL MANUFACTURER: The diffused air, aeration system sha11 be Air Fln 3 SV5t�-r11i1r---- a5 rnanufmurW boy Otterbine 6arebo. Inc.3840 MAIN ROAD EAST, Ernmaus, PA 1 ZD419, U_�A EH. (61 0) 96S-60181 or approved equal. F-or approved equal status, supplier sh all provide the following Information t4 khe pr+aje!St de0gngr, within 1 U days of the bid opening dart, for Wrltren approval. WARRANT'r: The aeration system sha11 inc-lud e a two year warranty a n Lhe air corn pressor, air diffuser and * of 41t!fuse r SYrF$M C6rnPmAs00) Pad(s) * Discs N else Der�lrti 5-Yslrlrtt -' g� ,tm Px AlF3•l21 3 A 3 I 7 4 1 I i 1 � 5 11314,7}¢q 4 i 23012.5}50 2 �2i512.8}So 4 I AF3-131 AF3-14 i AF3-112 AF3-122 AlF3•i4i ! 4 $ 2 I a - � 8 4 B 1 11 4 23414.7f60 f 22o�S.fi}58 B 12 AF3'23 r AFE•222 2 br3-�3L � �rF]•2�2 A' 13-i52 underwalter tubing, AF - 4 ; P/N 0 - 242 OR APPROVED EQUAL JS Onn C: r1 C; Air Fla 3 D:f .ed Air System Speciricarions I Page 2 at Z N Y+�f N +M 1,r,i' t}' r i _ -- - - - - Ss: r - AIR FL DIFFUSED AERATION >a �o electrical parts inln'at�r, safe for re�rratit�rt211 U�rc- � _.sF --'- -�F. ����� V Cxtrerncly energy efficient and cask effvcli%-�. 12in(350mai) d,scs coatcdl to pro%idlc non-stick .r C ­U]rfac sited offer higher efficl,encies throw pout Ca�ry�rt-:max Clb+rei W-9k9PK lduwm CJgerarir depths up to 40ftt or I2.'_'ut+_ P R o n Sr e T ILLUSTRATIONS v }rIl'd1'iill). -1r14'i4tSI�IE! tcinrl'lilt}''' Ar FIa1P++.nN Lr Pew-s-wp-L+!'i'mr PfAco E h. r.p p., h-.o.F-... N-..,o F-%..M,y d,rgF. yt N 47h a, 12ra >� ('emplete packa-_,e includeti cabin -et iiilkwulpreL�sQA5), WIMPMEW IanM mldir ,Y dnl.drr,earhldu 4ru4d. or du16 ,'ricer and �'altie rttagiFrlld; and dJ Ffllser manifold(s). aA4 sir nueddd hAx 11 eerehuePM N high din sly poledrrk•e p4Rc APd idwr perax WLss, Owir%II rot SI �i7fcjy tested and listed with Ei'L & ETL- C, c-o Furm i m keel pndn7 0 RNb " Iro9Y41 m LQ UL standards. iWd -� 2lFiQ'- �L 39-a Pi-lrty listin.1 wIr" ICFf'r s C"I" etl dgaupL3M II71+less oeelta[+rec a SNIIRH114+r d4tR+4l14a m•kw M [}-r..rl 4-4 L?W {Ia"d 6-h.-1 6 N *fm m 15 SY'4TEW ad DEW44!,P9'ri61 rDesti sarc y„kf,..mp17G Ca.• pw..oly7 NrI ratl /dr % �.r Y 16..16,.xAL Frr F+Ina1;h . Fanr .1i7 •1i1 ; 7 _ La4u.t.ndl,u ty Lh- .,sl,d4 C21-1.1 r.w 1h..1&-.Ir Aid .r11� t 1 r ara.dK,anrbiJwr�. it ...pent casie,4 sr*.eh-o.,i _-_ 11�M.JAX • drrmear3251.•rasprr,nllux. JYL^I .1+11 I 1 i ]30.r2,Sfo- - Val.,: grad OB4ar 6sac 6.Im rah., rr alraw Mr ro m Af3 u2 1 t y 9Z0.r�.ir�• upamrra*rmustAirRaislsurm- wP3 cAiwa uwlvarur rnhnd hr W61i'lesI RM hmhr 1IL , aowlrAMdrna WIFJrp ilraMNl'a An.261 C..Pi&./> Up.,. v r.r1'1..Wd, a PP&MA and IHAd��ur en _ ►Ad ESL C. Nadual Oar dw E.rap mkmk-nil yw saNy uiDA afP'". ar 2CrL("Wk3do,_ Woburn uFn 1rg fylry awi•� t 2 2 Duyhyraa 'a _ ,I.rr.,...n.ra.u. so..Nrdlur w prudu.l,..l,rg ar.d awi.23t 7 Y awY 2aL # E Pia ma sWGU`kpQom4r4i"d €_prcan be jcaed"N as Af1;,tfi� 5 13 3 rilratlryii yaw arkFblHa_enln av WW.CMM&Alrr.tWH AF -24 ; P/N 03-3242 OR APPROVED EQUAL VA DEQ STORMWATER DESIGN SPECIFICATION NO. 14 1/2" ninc ptatad 'nook SECTION 4: TYPICAL DETAM ELLte.cFed with 9/8r easkener UPpER9NELP WErL4NO LVEL 2) VoETLANR CE_L 'NrLOW FROM FOREDAY QVERFL9hry MAX TV OEFTH - 12' n(1F1EELAY MEFEFI 70 TABLE 14.2 FOR VOLUME (REFER TDTAEILE REOUIFiEMENTSI aar�', ae1cH 14.2 FOR VOLUME - --� ar t-1r,A.. dl,i. hulr.x REC+_IAEMENT'y) �Tr, 06 LOW FLOh+d 416 1/4' HDPE pale (oplional)PLpe - Culvert ryas' •, H13H FLOLV LANDSCARING R}N6 AERKTICN IAEFER707ASLE1E.2 ~'" •• FDA L, AND L2 OA71C BENCH l • y" ffPPF xi.ruC.i.11Tr1 pl2dxtir. yrii.F' RErx_�EMENTG} 8AFETrBENCH 2-1fli" ho1cs and 1/�" plato Wrr`eA0JAT10 nzanu_acLurcd by 731ax:,ic BENCH 00 iohiLions rnc. ar equal PLANMEVJ 0000 -- ii r'A I {; V i3 1. I LJ ft * sham With optfarel platy Hj}YF st.-,Arl.'.ArrAl nl��i.ir� xil.h ' fP" holed WILL 114 plate _ure.ctured try Plestie ,Itions L7C or c`quo.! LSPLASTI OLMONS INC. P.D. Rvs L.3t9fi hincies.er V,1 22M4 �I'f 7-87 7- 572 7 tk a.Plas4c-WL -_A�,Com WET POND otitfLEr FF--TECT ION F LOW F ATH AND POOL (3E0ME7F1't DER TO TAELE 14.2 FOR L i AND L 2 REO UIREMEN TS) NOTE REFER 76 TABLE 14.2 ANO C E9F3N SPEC NO. 93 60Ftl3TRJC= V FE N❑ 5O :T10N E. FO R Li ANa Li VCUJME AP40 * TORAGE CEM-H CArrEFEA I N LVETLA NO CELL OVVERF LOW PO WFT FCC 9 NORMAL SArETY Grw_ PA C+IANNEL PFIOTECTION � � .aOLr4TwC BEF,ICH I, -' TV � NORMAL P<XIL - �\\ .CM FLDW T4 UPPER SHELF WETLAND . llx PROFILE (WITH UPPER SHF=LF V'VETLAND) EbEPZE SLOPE LONE FLOW IPE FORMAY ALL~' ` E __ _ _ 1 NI4tiFL4w'rT4'r1�rR4NRh14III-III IIII-III-II III-III-IiI- - "III Fa lfjJ=�l - REUEREF BLCIFIE LOw ELUw PIPE NCATE. RETBR TO SECTkDN $ FCR L1 AND L 2 NORMhL FOOL VOLUME , AND NTH AND TV AMD ENAMEL PAOTFL'Tor4 g-ru Aor DEPTHS PROFILE ITHOUT UPPER SHELF IVETL4KIM Figirre 1A-P. VVet Pond Design Schemarics FACILITY PLANTING SPECIFICATIONS: 1. THE CONTRACTOR SHALL ESTABLISH AND MAINTAIN A VEGETATIVE COVERAGE IN THE POND AND ITS BUFFER. 2. THE CONTRACTOR SHALL ALSO INSTALL THE WETLAND SHELF AND AQUATIC BENCH PLANTINGS, AS REQUIRED, AND USE NUTRIENT RICH SOIL IN THESE AREAS TO PROMOTE HEALTHY GROWTH AND ROOT DEVELOPMENT. 3. PLANT SELECTION SHALL PROMOTE DIVERSE WILDLIFE AND WATERFOWL USE WITHIN THE STORMWATER WETLAND, AQUATIC BENCH AND BUFFERS. 4. WOODY VEGETATION MAY NOT BE PLANTED OR ALLOWED TO GROW WITHIN 15 FEET OF THE TOE OF THE EMBANKMENT NOR WITHIN 25 FEET FROM THE PRINCIPAL SPILLWAY STRUCTURE. 5. A VEGETATED BUFFER SHALL BE PROVIDED THAT EXTENDS AT LEAST 25 FEET OUTWARD FROM THE MAXIMUM WATER SURFACE ELEVATION OF THE WET POND. PERMANENT STRUCTURES E.G. BUILDINGS SHALL NOT BE CONSTRUCTED WITHIN THE BUFFER AREA. EXISTING TREES SHALL BE PRESERVED IN THE BUFFER AREA DURING CONSTRUCTION IF POSSIBLE. 6. THE SOILS IN THE STORMWATER BUFFER AREA ARE OFTEN SEVERELY COMPACTED DURING THE CONSTRUCTION PROCESS TO ENSURE STABILITY. THE DENSITY OF THESE COMPACTED SOILS CAN BE SO GREAT THAT IT EFFECTIVELY PREVENTS ROOT PENETRATION AND, THEREFORE, MAY LEAD TO PREMATURE MORTALITY OR LOSS OF VIGOR. AS A RULE OF THUMB, PLANTING HOLES SHALL BE THREE TIMES DEEPER AND WIDER THAN THE DIAMETER OF THE ROOT BALL FOR BALL -AND -BURLAP STOCK AND FIVE TIMES DEEPER AND WIDER FOR CONTAINER -GROWN STOCK. 7. AVOID SPECIES THAT REQUIRE FULL SHADE, OR ARE PRONE TO WIND DAMAGE. EXTRA MULCHING AROUND THE BASE OF TREES AND SHRUBS IS STRONGLY RECOMMENDED AS A MEANS OF CONSERVING MOISTURE AND SUPPRESSING WEEDS. CONTRACTOR REQUIREMENTS: 1. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS. 2. LANDSCAPE CONTRACTOR SHALL REFER TO THE STANDARDIZED LANDSCAPE SPECIFICATIONS FOR THE STATE OF VIRGINIA FOR ADDITIONAL INFORMATION. THE CONTRACTOR SHALL ABIDE BY ITS CONTENTS; HOWEVER ANY NOTES OR SPECIFICATIONS ON THE PLANS SHALL SUPERSEDE THOSE OUTLINED IN THE SPECIFICATIONS MANUAL (COPIES ARE AVAILABLE FOR A FEE FROM THE VIRGINIA CHAPTER OF THE AMERICAN SOCIETY OF LANDSCAPE ARCHITECTS, VIRGINIA NURSERYMEN'S ASSOCIATION, INC. AND THE VIRGINIA SOCIETY OF LANDSCAPE DESIGNERS). 3. ALL PLANT MATERIAL SHALL MEET THE MINIMUM SPECIFICATIONS AND STANDARDS DESCRIBED IN THE CURRENT ISSUE OF THE AMERICAN STANDARD FOR NURSERY STOCK, PUBLISHED BY THE AMERICAN ASSOCIATION OF NURSERYMEN, 1250 STREET, NW, SUITE 500, WASHINGTON, DC 20005. 4. THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE DESIGNER OF ANY VARIANCE FROM THE PLAN. 5. THE LANDSCAPE CONTRACTOR IS RESPONSIBLE FOR VERIFYING THE LOCATION OF ANY ONSITE UTILITIES (CALL MISS UTILITY 1-800-552-7001 BEFORE ANY EXCAVATION). 6. REFER TO THE APPROVED CONSTRUCTION PLANS FOR ANY DETAILED SITE INFORMATION. 7. ALL WORK SHALL BE COORDINATED WITH OTHER PARTIES. 8. PLANTS WILL BE PREPARED FOR SHIPMENT IN A MANNER THAT WILL NOT CAUSE DAMAGE TO THE BARK, BUDS, BRANCHES, STEMS, OR OVERALL SHAPE OF THE STOCK. CONTAINER GROWN PLANTS WILL BE TRANSPORTED IN THE CONTAINERS IN WHICH THEY HAVE BEEN GROWN. 9. ALL PLANT MATERIAL, UNLESS OTHERWISE SPECIFIED, SHALL BE UNIFORMLY BRANCHED AND HAVE A VIGOROUS ROOT SYSTEM. PLANT MATERIAL SHALL BE HEALTHY, VIGOROUS, AND FREE FROM DEFECTS, DECAY, DISEASES, INSECT PEST EGGS, AND ALL FORMS OF INFESTATION. ALL PLANT MATERIAL SHALL BE FRESH, FREE FROM TRANSPLANT SHOCK OR VISIBLE WILT. PLANTS DEEMED UNHEALTHY WILL BE REJECTED. 10.ALL CONTAINER STOCK SHALL HAVE BEEN PROPAGATED IN A CONTAINER LONG ENOUGH FOR THE ROOT SYSTEM TO HAVE DEVELOPED SUFFICIENTLY TO HOLD ITS SOIL. CONTAINER STOCK WITH POORLY DEVELOPED ROOT SYSTEMS WILL NOT BE ACCEPTED. 11.PLANTS NOT INSTALLED ON THE DAY OF ARRIVAL ON SITE SHALL BE STORED AND PROTECTED BY THE CONTAINER. OUTSIDE STORAGE AREAS WILL BE SHADED AND PROTECTED FROM THE WIND AND SUN. PLANTS STORED ON SITE SHALL BE PROTECTED FROM ANY DRYING AT ALL TIMES BY COVERING THE BALLS OR ROOTS WITH MOIST SAWDUST, WET BURLAP, WOOD CHIPS, SHREDDED BARK, PEAT MOSS, OR OTHER SIMILAR MULCHING MATERIAL. 12.THE OWNER RESERVES THE RIGHT TO SUBSTITUTE PLANT MATERIAL TYPE, SIZE AND/OR QUANTITY. ANY SUBSTITUTIONS MUST BE APPROVED BY THE DESIGNER. 13.MINOR FIELD ADJUSTMENTS MAY BE NECESSARY DUE TO SITE CONDITIONS (EX: ROOTBALL AND UTILITY CONFLICT). MAJOR ADJUSTMENTS MUST BE APPROVED BY THE DESIGNER. 14.NO PLANTING SHALL OCCUR WHEN THE SOIL IS FROZEN. 15.PLANT MATERIAL SHALL BE PLACED IN EXISTING SOIL WITH EACH PLANTING PIT EXCAVATED TO A SIZE SUFFICIENT TO CONTAIN THE ENTIRE ROOT BALL OR ROOT MASS, WITHOUT CRAMPING ROOT STOCK. 16.THE CONTRACTOR SHALL MAINTAIN A ONE (1) CALENDAR YEAR 90% CARE AND REPLACEMENT WARRANTY FOR ALL PLANTINGS. THE PERIOD OF CARE AND REPLACEMENT SHALL BEGIN AFTER INSPECTION AND APPROVAL OF THE COMPLETE INSTALLATION OF ALL PLANTS AND CONTINUE FOR ONE CALENDAR YEAR. 17.THE CONTRACTOR IS RESPONSIBLE FOR REMOVAL AND DISPOSAL OF TRASH AND DEBRIS WITHIN THE LIMITS OF THE PLANTING ON A DAILY BASIS. 18.THE CONTRACTOR WILL NOT BE RESPONSIBLE FOR PLANT MATERIAL THAT HAS BEEN DAMAGED BY VANDALISM, FIRE, OR OTHER ACTIVITIES BEYOND THE CONTRACTOR'S CONTROL. FACILITY CONSTRUCTION: 1. THE CONTRACTOR SHALL USE THE WET POND AS AN E&S CONTROL STRUCTURE, IF SHOWN IN THIS MANNER ON THE APPROVED ESC PLANS. IF APPLICABLE, THE WET POND SHALL SERVE AS A SEDIMENT BASIN DURING PROJECT CONSTRUCTION. IF THIS IS DONE, THE VOLUME SHALL BE BASED ON THE MORE STRINGENT SIZING RULE (EROSION AND SEDIMENT CONTROL REQUIREMENT VS. WATER QUALITY TREATMENT REQUIREMENT). INSTALLATION OF THE PERMANENT RISER SHALL BE INITIATED DURING THE CONSTRUCTION PHASE, AND DESIGN ELEVATIONS SHALL BE SET WITH FINAL CLEANOUT OF THE SEDIMENT BASIN AND CONVERSION TO THE POST -CONSTRUCTION WET POND IN MIND. THE BOTTOM ELEVATION OF THE WET POND SHALL BE LOWER THAN THE BOTTOM ELEVATION OF THE TEMPORARY SEDIMENT BASIN/TRAP WHEN POSSIBLE. APPROPRIATE PROCEDURES SHALL BE IMPLEMENTED TO PREVENT DISCHARGE OF TURBID WATERS WHEN THE BASIN/TRAP IS BEING CONVERTED INTO A WET POND. 2. WET PONDS SHALL ONLY BE CONSTRUCTED AFTER THE CONTRIBUTING DRAINAGE AREA TO THE POND IS COMPLETELY STABILIZED. IF THE PROPOSED POND SITE WILL BE USED AS A SEDIMENT TRAP OR BASIN DURING THE CONSTRUCTION PHASE, THE CONTRACTOR SHALL DE -WATER, DREDGE AND RE -GRADE THE SEDIMENT CONTROL FACILITY TO DESIGN DIMENSIONS AFTER THE ORIGINAL SITE CONSTRUCTION IS COMPLETE. 3. THE CONTRACTOR SHALL ASSEMBLE CONSTRUCTION MATERIALS ON -SITE, MAKING SURE THEY MEET DESIGN SPECIFICATIONS AND ARE PREPARED AT STAGING AREAS WHEN POSSIBLE. 4. THE CONTRACTOR SHALL CLEAR AND STRIP THE PROJECT AREA IF REQUIRED TO THE DESIRED SUB -GRADE. 5. THE CONTRACTOR SHALL INSTALL E&S CONTROLS PRIOR TO CONSTRUCTION, INCLUDING TEMPORARY DE -WATERING DEVICES AND STORMWATER DIVERSION PRACTICES. ALL AREAS SURROUNDING THE POND THAT ARE GRADED OR DENUDED DURING CONSTRUCTION MUST BE PLANTED WITH TURF GRASS, NATIVE PLANTINGS, OR OTHER APPROVED METHODS OF SOIL STABILIZATION. 6. THE CONTRACTOR SHALL ALSO EXCAVATE THE CORE TRENCH AND INSTALL THE SPILLWAY PIPE. 7. THE RISER AND APPLICABLE OUTFLOW STRUCTURES SHALL BE INSTALLED, AND THE CONTRACTOR SHALL ENSURE THE TOP INVERT OF THE OVERFLOW WEIR(S) ARE CONSTRUCTED LEVEL AT THE DESIGN ELEVATION(S). 8. THE CONTRACTOR SHALL CONSTRUCT THE EMBANKMENT AND ANY INTERNAL BERMS IN 8- TO 12-INCH LIFTS, COMPACTION SHALL BE COMPLETED IN LIFTS WITH APPROPRIATE EQUIPMENT. THE CONTRACTOR SHALL ALSO ADHERE TO THE CLAY LINER SPECIFICATIONS OUTLINED IN TABLE 14.4 BELOW: Tab, e 14.4, Clay LNler Specrfeariarls Property Test Mathod Unit Speciflication Permeability ASTM D-2434 CrNsec 1 x ie Plasticity Index of Cloy ASTM 1)423N424 % Not less than 15 Liquid Limit of Clay ASTM D3-2216 % Not less than 30 Clay Particles Passing ASTM D-422 % Not less than 30 Clay CQrnpactiQn ASTM D-2210 % 1 95% of standard prodar dins WUrCe: VIriginlaZj10FMWa18FinanagementHanaDooKtisa#Nl 9. EXCAVATION AND GRADING TO THE APPROPRIATE ELEVATIONS AND DESIRED CONTOURS SHALL BE ACHIEVED FOR THE BOTTOM AND SIDE SLOPES OF THE POND. 10.THE EMERGENCY SPILLWAY SHALL BE CONSTRUCTED IN CUT WHERE POSSIBLE, OR IN STRUCTURALLY STABILIZED SOILS. 11.THE OUTLET PIPES, INCLUDING DOWNSTREAM RIP -RAP APRON PROTECTION, SHALL BE INSTALLED. 12.EXPOSED SOILS SHALL BE STABILIZED WITH TEMPORARY SEED MIXTURES APPROPRIATE FOR THE POND BUFFER. ALL AREAS ABOVE THE NORMAL POOL ELEVATION SHALL BE PERMANENTLY STABILIZED BY HYDROSEEDING OR SEEDING OVER STRAW. 13.THE POND BUFFER AREA SHALL BE PLANTED WITH A VEGETATIVE GROUND COVER AND THE CONTRACTOR SHALL THEN INSTALL THE APPROPRIATE BASIN LANDSCAPING IN ACCORDANCE WITH THE APPROVED PLANS. 14.ALL CONSTRUCTION SHALL ADHERE TO THE VIRGINIA DEQ POST CONSTRUCTION BMP CLEARINGHOUSE REQUIREMENTS SET FORTH IN DESIGN SPECIFICATION NUMBER 14. FACILITY MAINTENANCE: MAINTENANCE OF THE WET POND(S) IS DRIVEN BY ANNUAL INSPECTIONS THAT EVALUATE THE CONDITION AND PERFORMANCE OF THE POND. DURING THESE INSPECTIONS THE FOLLOWING TASKS SHALL BE PERFORMED BY THE CONTRACTOR IN THE FIRST YEAR FOLLOWING INSTALLATION, AND THE OWNER THEREAFTER: 1. MEASURE SEDIMENT ACCUMULATION LEVELS IN THE FOREBAY. 1. MONITOR THE GROWTH OF WETLANDS, TREES AND SHRUBS PLANTED, AS APPLICABLE. RECORD THE SPECIES AND THEIR APPROXIMATE COVERAGE, AND NOTE THE PRESENCE OF ANY INVASIVE PLANT SPECIES, AS APPLICABLE. 2. INSPECT THE CONDITION OF STORMWATER INLETS TO THE POND FOR MATERIAL DAMAGE, EROSION OR UNDERCUTTING. 3. INSPECT THE BANKS OF UPSTREAM AND DOWNSTREAM CHANNELS FOR EVIDENCE OF SLOUGHING, ANIMAL BURROWS, BOGGY AREAS, WOODY GROWTH, OR GULLY EROSION THAT MAY UNDERMINE EMBANKMENT INTEGRITY. 4. INSPECT POND OUTFALL CHANNEL FOR EROSION, UNDERCUTTING, RIP -RAP DISPLACEMENT, WOODY GROWTH, ETC. 5. INSPECT CONDITION OF PRINCIPAL SPILLWAY, EMERGENCY SPILLWAY, RISER, ORIFICES & TRASHRACKS FOR EVIDENCE OF SPALLING, JOINT FAILURE, LEAKAGE, CORROSION OR OTHER FAILURES. 6. INSPECT CONDITION OF ALL TRASH RACKS OR FLASHBOARD RISERS FOR EVIDENCE OF CLOGGING, LEAKAGE, DEBRIS ACCUMULATION OR OTHER FAILURES. 7. INSPECT MAINTENANCE ACCESS TO ENSURE IT IS FREE OF WOODY VEGETATION, AND CHECK TO SEE WHETHER VALVES, MANHOLES AND LOCKS CAN BE OPENED AND OPERATED. 8. INSPECT INTERNAL AND EXTERNAL SIDE SLOPES OF THE POND FOR EVIDENCE OF SPARSE VEGETATIVE COVER, EROSION, OR SLUMPING, AND MAKE NEEDED REPAIRS IMMEDIATELY. 9. REPAIR AND REPLACE AS NECESSARY. 10.PLEASE SEE THE TABLE BELOW FOR ADDITIONAL MAINTENANCE MEASURES ABOVE AND BEYOND THOSE OUTLINED ABOVE: Table 14.& Typical Wet Pond Maim-enance Tasks and Filegaency Maintenance Items Frequency ■ Mowing -twice a year Quarterly c r after major storm s ■ Remove debris and blockages (}1 inch of rainfall) * Repair undercut, eroded, and bare sail Xeas * Mooring Twice a year * Shoreline cleanup to remove trash, debris and flaatables + Afull maintenance inspection Annually + Open u p th a riser to access and fast the vnives + Repair broken mechanical components, I needed One time -during the + Pond buffer and aquatic bench reinforcement plxyfi lgs second WarTgl"ng construction • Fweba Sediment Remaval Every 5to 7 years + Repair pi W. the riser ands it Iva , as needed From 5 to 25 years FACILITY INSPECTION: MULTIPLE INSPECTIONS ARE CRITICAL TO ENSURE THE BASIN(S) ARE PROPERLY CONSTRUCTED. BECAUSE THE TIMING OF THE INSTALLATION IS DICTATED BY THE CONTRACTOR, THE CONTRACTOR SHALL BE RESPONSIBLE FOR CONTACTING THE ENGINEER AND INSPECTOR PRIOR TO INSTALLATION. MULTIPLE SITE VISITS AND INSPECTIONS ARE REQUIRED TO BE SCHEDULED BY THE CONTRACTOR, WITH THE ENGINEER AND INSPECTOR, DURING THE FOLLOWING STAGES OF THE WET POND'S CONSTRUCTION PROCESS: 1. PRE -CONSTRUCTION MEETING 2. INITIAL SITE PREPARATION (INCLUDING INSTALLATION OF PROJECT E&S CONTROLS) 3. EXCAVATION/GRADING (E.G., INTERIM/FINAL ELEVATIONS) 4. WET POND INSTALLATION (E.G., INTERIM AND FINAL ELEVATIONS) 5. INSTALLATION OF THE EMBANKMENT, EMERGENCY SPILLWAY, THE RISER/PRIMARY SPILLWAY AND THE OUTLET CONTROL STRUCTURE(S). 6. PLANTING AND VEGETATIVE STABILIZATION PHASE (WITH AN EXPERIENCED LANDSCAPE ARCHITECT PRESENT) 7. FINAL INSPECTION (DEVELOP A PUNCH LIST FOR FACILITY ACCEPTANCE) SCOTT R. 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