Loading...
Seney Sheet 2 Stormwater permit-SITE PLANTP-1TP-2TP-3TP-4TP-5TP-6PLANTING MEDIA20"COARSE GRAVEL FILLUNDISTURBED ORSCARIFIED SUBGRADE-40% SAND-20% TOPSOIL-40% COMPOSTELEV. VARIES6" PERFORATED HDPE UNDERDRAINSTONE DIAPHRAGM4NOT TO SCALE8"3"SIDESLOPE 4:1 MAX LOAM & SEED (SEE NOTE)NOTES:1.SEED SIDES AND BOTTOM OF RAIN GARDEN WITH "NEW ENGLANDEROSION CONTROL/RESTORATION MIX FOR DETENTION BASINS ANDMOIST SITES" MIX FROM NEW ENGLAND WETLANDS PLANTS.2.PROTECT RAIN GARDEN FROM RUNOFF UNTIL THE TRIBUTARY AREAIS STABILIZED AND A VIABLE VEGETATIVE COVER HAS BEENACHIEVED WITHIN THE RAIN GARDEN.RAIN GARDEN1NOT TO SCALELEVEL SPREADER3NOT TO SCALEELEV. VARIES3"SIDESLOPE 4:1 MAX LOAM & SEED (SEE NOTE)INFILTRATION BASIN2NOT TO SCALEEROSION CONTROL NOTES1.THE CONTRACTOR SHALL INSTALL EROSION CONTROL DEVICES AS NECESSARY TO PREVENT EROSION WITHIN THE SITE ANDMIGRATION OF SEDIMENT OUT OF THE SITE, OR AS DIRECTED BY THE ENGINEER. ALL DEVICES SHALL COMPLY WITH THEMASSACHUSETTS EROSION AND SEDIMENT CONTROL GUIDELINES, CURRENT VERSION.2.THE PROPOSED WORK WILL DISTURB MORE THAN ONE ACRE OF LAND, AND IS SUBJECT TO PERMITTING BY THE USENVIRONMENTAL PROTECTION AGENCY (EPA) UNDER THE NPDES CONSTRUCTION ACTIVITIES PERMIT. THE CONTRACTOR ISRESPONSIBLE FOR COMPLIANCE WITH THE NPDES PERMIT, INCLUDING PREPARATION AND MAINTENANCE OF ASTORMWATER POLLUTION PREVENTION PLAN (SWPPP) FOR THE SITE.3.THE PROPOSED PROJECT IS SUBJECT TO PERMITTING BY THE CITY OF NORTHAMPTON UNDER THE NORTHAMPTONSTORMWATER PERMIT. THE CONTRACTOR SHALL COMPLY WITH ALL CONDITIONS OF THE STORMWATER PERMIT.4.ALL VEHICLES ENTERING AND EXITING THE SITE SHALL BE REQUIRED TO CROSS A TRACKING PAD TO PREVENT TRACKING OFSEDIMENT ONTO CAMPUS OR PUBLIC ROADWAYS. IF SEDIMENT IS FOUND ON ROADWAYS, THE SEDIMENT SHALL BEREMOVED IMMEDIATELY.5.STORMWATER MANAGEMENT AREA LOCATIONS SHALL BE PROTECTED FROM CONSTRUCTION TRAFFIC AT ALL TIMES.EROSION CONTROL BARRIERS SHALL BE MAINTAINED AROUND THE INFILTRATION AREAS AND THE RAIN GARDEN UNTIL THETRIBUTARY DRAINAGE AREA HAS BEEN STABILIZED AND THE PLANTINGS HAVE ESTABLISHED A VIABLE STABLE VEGETATIVECOVER.6.ALL DEWATERING DISCHARGES SHALL BE DIRECTED TO A DEWATERING FILTER BAG OR SEDIMENT TRAP.7.ALL DRAINAGE INLETS WITHIN AND DOWNSTREAM OF THE SITE SHALL BE PROTECTED WITH SEDIMENT BARRIER (SILT SACKOR EQUAL).8.ALL SEDIMENT STOCKPILES SHALL BE SURROUNDED BY A CONTINUOUS SILT FENCE. IF THE STOCKPILE WILL REMAIN UNUSEDFOR MORE THAN 14 DAYS, THE STOCKPILE SHALL BE STABILIZED BY SEEDING.9.ALL DISTURBED SLOPES GREATER THAN 5H:1V SHALL BE PROTECTED FROM EROSION BY THE INSTALLATION OFBIO-DEGRADABLE OR PHOTO-DEGRADABLE EROSION CONTROL BLANKETS. EROSION CONTROL BLANKETS SHALL BE USED INOTHER LOCATIONS AS DIRECTED BY THE ENGINEER, IF OTHER MEANS OF EROSION CONTROL ARE FOUND TO BEINADEQUATE.10.THE CONTRACTOR SHALL INSPECT ALL INSTALLED EROSION CONTROL DEVICES A MINIMUM OF ONCE PER WEEK AND AFTEREACH STORM. IF ANY DEVICE IS FOUND TO BE DAMAGED, THE CONTRACTOR SHALL REPAIR IT IMMEDIATELY. IF SEDIMENT ISFOUND TO FILL MORE THAN HALF THE HEIGHT OF THE DEVICE, THE SEDIMENT SHALL BE REMOVED OR THE DEVICEREPLACED.11.THE CONTRACTOR SHALL MAINTAIN A STOCKPILE OF EXTRA EROSION CONTROL MATERIALS ON SITE AT ALL TIMES.12.THE CONTRACTOR SHALL IMPLEMENT SPILL-PREVENTION PROCEDURES AND MAINTAIN A SPILL PREVENTION AND CLEANUPPLAN FOR THE SITE. ALL MATERIALS THAT ARE CAPABLE OF SPILLING, LEAKING, DISSOLVING OR OTHERWISE POLLUTINGSTORMWATER RUNOFF SHALL BE COVERED WHILE STORED AT THE SITE.13.ALL MATERIALS THAT ARE CAPABLE OF SPILLING, LEAKING, DISSOLVING OR OTHERWISE POLLUTING STORMWATER RUNOFFSHALL BE COVERED WHILE STORED AT THE SITE.14.ALL SEDIMENT REMOVED FROM THE SITE SHALL BE HANDLED IN ACCORDANCE WITH STATE AND LOCAL REGULATIONS.15.ALL TEMPORARY EROSION CONTROLS SHALL BE REMOVED FROM THE SITE PRIOR TO THE COMPLETION OF THE WORK,EXCEPT WHERE DEGRADABLE MATERIALS ARE TO REMAIN IN-PLACE PERMANENTLY.ORGANIC FILTER BERM8NOT TO SCALEORGANIC FILTER BERM NOTES:1.ORGANIC FILTER BERMS MAY BE UTILIZED IN LIEU OF SILT FENCE.2.THE EROSION CONTROL MIX USED IN THE FILTER BERMS SHALL BE AWELL-GRADED MIXTURE OF PARTICLE SIZES, MAY CONTAIN ROCKS LESSTHAN 4 IN DIAMETER, STUMP GRINDINGS, SHREDDED OR COMPOSEDBARK, OR ACCEPTABLE MANUFACTURED PRODUCTS, AND SHALL BEFREE OF REFUSE AND PHYSICAL CONTAMINANTS, AND MATERIALTOXIC TO PLAN GROWTH. IT SHALL MEET THE FOLLOWINGSTANDARDS:A.THE ORGANIC CONTENT SHALL BE 80-100% BY DRY WEIGHT.B.PARTICLE SIZE BY WEIGHT SHALL BE 100% PASSING A 6" SCREENAND 70-85% PASSING A 0.75" SCREEN.C.THE ORGANIC PORTION SHALL BE FIBROUS AND ELONGATED.D.LARGE PORTIONS OF SILTS, CLAYS, OR FINE SANDS SHALL NOT BEINCLUDED IN THE MIXTURES.3.ORGANIC FILTER BERMS SHALL BE INSTALLED ALONG A RELATIVELYLEVEL CONTOUR. IT MAY BE NECESSARY TO CUT TALL GRASSES ORWOODY VEGETATION TO AVOID CREATING VOIDS AND BRIDGES THATWOULD ENABLE FINES TO WASH UNDER THE BERM.4.FROZEN GROUND, OUTCROPS OF BEDROCK, AND VERY ROOTEDFORESTED AREAS PRESENT THE MOST PRACTICAL AND EFFECTIVELOCATIONS FOR ORGANIC FILTER BERMS. OTHER BMPS SHOULD BEUSED AT LOW POINTS OF CONCENTRATED RUNOFF, BELOW CULVERTOUTLET APRONS, AROUND CATCH BASINS AND AT THE BOTTOM OFSTEEP PERIMETER SLOPES THAT HAVE A LARGE CONTRIBUTING AREA.5.SEDIMENT SHALL BE REMOVED FROM BEHIND THE STRUCTURES WHENIT HAS ACCUMULATED TO ONE HALF THE ORIGINAL HEIGHT OF THESTRUCTURE.6.STRUCTURES MAY BE LEFT IN PLACE ONE THE SITE IS STABILIZED. SILTSACK® SPECIFICATIONSNOTE: THE SILTSACK WILL BE MANUFACTURED FROM A WOVEN POLYPROPYLENE FABRIC THAT MEETS OR EXCEEDS THE FOLLOWING SPECIFICATIONS.REGULAR FLOW SILTSACK® (REG)(FOR AREAS OF LOW TO MODERATE PRECIPITATION AND RUN-OFF)HI-FLOW SILTSACK® (HI)(FOR AREAS OF MODERATE TO HIGH PRECIPITATION AND RUN-OFF) PROPERTIES TEST METHOD UNITS (REG) UNITS (HI)GRAB TENSILE STRENGTHASTM D-4632 300 LBS 265 LBSGRAB TENSILE ELONGATION ASTM D-4632 20 %20 %PUNCTURE ASTM D-4833 120 LBS135 LBSMULLEN BURST ASTM D-3786 800 PSI420 PSITRAPEZOID TEAR ASTM D-4533 120 LBS45 LBSUV RESISTANCE ASTM D-4355 80 %90 %APPARENT OPENING SIZE ASTM D-4751 40 US SIEVE 20 US SIEVEFLOW RATE ASTM D-449140 GAL/MIN/SQ FT200 GAL/MIN/SQ FTPERMITTIVITY ASTM D-4491 0.55 SEC (-1)1.5 SEC (-1)OIL-ABSORBANT SILTSACK®(FOR AREAS WHERE THERE IS A CONCERN FOR OIL RUN-OFF OR SPILLS)DEPENDING ON YOUR PARTICULAR APPLICATION, THE SILTSACK® CAN BE MADE:(1). FROM EITHER OF THE ABOVE FABRICS WITH AN OIL-ABSORBANT PILLOW INSERT, OR(2). COMPLETELY FROM AN OIL-ABSORBANT SILTSACK, WITH A WOVEN PILLOW INSERT.EROSION CONTROL INLET PROTECTION9NOT TO SCALEBOTTOM OF SWALE21NOTE:SWALES WITH SLOPES 10% AND OVER SHALL BE LINED WITH RIPRAP.TYPICAL RIPRAP SWALE5NOT TO SCALE4" DRAINAGE STONE12" RIPRAP - D50=6"12'' MIN DEPTH 4-6" RIP RAPSL O P E , T Y P . 12"BOTTOM AREA1. 5 : 1 S I D E 18"18"FILTER FABRICCONTINUOUSEXISTING VEGETATED GROUNDPROPOSED GRADEEXISTING GRADE5 FT WIDE OVERFLOW WEIR, 6" GRANITE OR PRECAST CURB LAID PERFECTLY FLATELEV. 1 INCH BELOW PIPE INVERT12" STORM DRAIN2'-0"OR SWALEUNDISTURBED OR COMPACTEDSUBGRADESTONE DIAPHRAGM FILLED WITHDRIVEWAY24''TOP OF STONE DIAPHRAGM TO BEVEGETATED SLOPE-LOAM AND SEED PER PLANTING PLAN2" BELOW TOP OF PAVEMENT2-4" DIA. STONE24"FILTER FABRICADJACENT ROLLS SHALLTIGHTLY ABUT12" DIA. STRAW WATTLESSECTIONSILT FENCE TUCKEDUNDER STRAW WATTLESILT FENCESILT FENCEENTRENCHED 3"FLOWEROSION CONTROL BARRIER7NOT TO SCALESTABILIZED CONSTRUCTION ENTRANCE6NOT TO SCALENOTES:1.SEED SIDES AND BOTTOM OF BASIN WITH "NEW ENGLAND EROSIONCONTROL/RESTORATION MIX FOR DETENTION BASINS AND MOISTSITES" MIX FROM NEW ENGLAND WETLANDS PLANTS.2.PROTECT BASIN FROM RUNOFF UNTIL THE TRIBUTARY AREA ISSTABILIZED AND A VIABLE VEGETATIVE COVER HAS BEEN ACHIEVEDWITHIN THE RAIN GARDEN.3' (MIN)1.5'MIN