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HomeMy WebLinkAboutSW3230801_Supplement-EZ Form_20240325 SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION 1 Project Name Conservancy at Waxhaw Phase 3 2 Project Area(ac) 74.35 3 Coastal Wetland Area(ac) 0 4 Surface Water Area(ac) 0.09 5 Is this project High or Low Density? High 6 Does this project use an off-site SCM? No COMPLIANCE WITH 02H.1003(4) 7 Width of vegetated setbacks provided(feet) 100 for Streams(200'for Waxhaw Creek) 8 Will the vegetated setback remain vegetated? Yes 9 If BUA is proposed in the setback,does it meet NCAC 02H.1003(4)(c-d)? Yes 10 Is streambank stabilization proposed on this project? No NUMBER AND TYPE OF SCMs: 11 Infiltration System 12 Bioretention Cell _ 13 Wet Pond 14 Stormwater Wetland 15 Permeable Pavement 16 Sand Filter 9 17 Rainwater Harvesting(RWH) 18 Green Roof 19 Level Spreader-Filter Strip(LS-FS) 20 Disconnected Impervious Surface(DIS) 21 Treatment Swale 22 Dry Pond 23 StormFilter 24 Silva Cell 25 Bayfilter 26 Filterra FORMS LOADED .DESIGNER CERTIFICATION 27 Name and Title: James P.Magennis,President 28 Organization: Construction Materials En ineerin &Consulting PC 29 Street address: PO Box . 30 City,State,Zip: Mt._Holly,NC 28120 31 Phone number(s): 704-361-8104 32 Email: jim@cmecpc.net Certification Statement: I certify,under penalty of law that this Supplement-EZ form and all supporting information were prepared under my direction or supervision:that the information provided in the form is to the best of my knowledge and belief,true,accurate,and complete;and that the engineering plans, specifications,operation and maintenance agreements and other supporting information are consistent with the information provided here. Designer �.•`0�H CA00°'•. SEAL 2489$ • Si ure of Designer �'9 •'•:�©1 ESP. Ss, 2� N t °0°geg i a 1 t a l t%%" '77/1//7-3 L Seal Date DRAINAGE AREAS 1 Is this a high density project? Yes 2 If so,number of drainage areas/SCMs 9 3 Does this project have low density areas? No 4 If so,number of low density drainage areas _ 0 Is all/part of this project subject to previous rule 5 versions? No FORMS LOADED DRAINAGE AREA INFORMATION Entire Site 1 2 3 4 5 6 4 Type of SCM Infiltration Basin Infiltration Basin Infiltration Basin Infiltration Basin Infiltration Basin Sand Filter 5 Total drainage area(sq ft) 1532658 91568 54723 351609 580153 359297 19350 6 Onsite drainage area(sq ft) 1532658 91568 54723 351609 580153 359297 19350 7 Offsite drainage area(sq ft) 8 Total BUA in project(sq ft) 319553 18699 sf 8389 sf 73770 sf 115962 sf 76339 sf 4844 sf New BUA on subdivided lots(subject to 9 permitting)(sq ft) 210672 13050 sf 3450 sf 58212 sf 82492 sf 50550 sf sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 108880 5649 sf 4939 sf 15557 sf 33470 sf 25789 sf 4844 sf 11 Offsite BUA(sq ft) 12 Breakdown of new BUA not on subdivided lots: -Parking(sq ft) 3048 3048 sf -Sidewalk(sq ft) -Roof(sq ft) -Roadway(sq ft) 105832 5649 sf 4939 sf 15557 sf 33470 sf 22741 sf 4844 sf -Future(sq ft) -Other,please specify in the comment box below(sq ft) New infiltrating permeable pavement on 13 subdivided lots(sq ft) N/A New infiltrating permeable pavement not on 14 subdivided lots(sq ft) N/A Existing BUA that will remain(not subject to 15 permitting)(sq ft) N/A 16 Existing BUA that is already permitted(sq ft) N/A 17 Existing BUA that will be removed(sq ft) N/A 18 Percent BUA 21% 20% 15% 21% 20% 21% 25% 19 Design storm(inches) 2.58 in 2.58 in 2.58 in 2.58 in 2.58 in 2.58 in 20 Design volume of SCM(cu ft) 4530 cf 1786 cf 13645 cf 24394 cf 16727 cf 436 cf 21 ,Calculation method for design volume Schueler Method ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): Drain areas 6-9 are for the treatment of roadway water where flow could not get into the Infiltration Basins 1-5. These are small filters within the roadside ditch for treatment before leaving the site. DRAINAGE AREAS 1 Is this a high density project? Yes 2 If so,number of drainage areas/SCMs 9 3 Does this project have low density areas? No 4 If so,number of low density drainage areas _ 0 Is all/part of this project subject to previous rule 5 versions? No FORMS LOADED DRAINAGE AREA INFORMATION Entire Site 7 8 9 4 Type of SCM Sand Filter Sand Filter Sand Filter 5 Total drainage area(sq ft) 1532658 14905 30189 30864 6 Onsite drainage area(sq ft) 1532658 14905 30189 30864 7 Offsite drainage area(sq ft) 8 Total BUA in project(sq ft) 319553 4750 sf 6983 sf 9817 sf New BUA on subdivided lots(subject to 9 permitting)(sq ft) 210672 sf sf 2918 sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 108880 4750 sf 6983 sf 6899 sf 11 Offsite BUA(sq ft) 12 Breakdown of new BUA not on subdivided lots: -Parking(sq ft) 3048 -Sidewalk(sq ft) -Roof(sq ft) -Roadway(sq ft) 105832 4750 sf 6983 sf 6899 sf -Future(sq ft) -Other,please specify in the comment box below(sq ft) New infiltrating permeable pavement on 13 subdivided lots(sq ft) N/A New infiltrating permeable pavement not on 14 subdivided lots(sq ft) N/A Existing BUA that will remain(not subject to 15 permitting)(sq ft) N/A 16 Existing BUA that is already permitted(sq ft) N/A 17 Existing BUA that will be removed(sq ft) N/A 18 Percent BUA 21% 32% 23% 32% 19 Design storm(inches) 2.58 in 2.58 in 2.58 in 20 Design volume of SCM(cu ft) 479 cf 436 cf 436 cf 21 ,Calculation method for design volume Schueler Method ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): Drain areas 6-9 are for the treatment of roadway water where flow could not get into the Infiltration Basins 1-5. These are small filters within the roadside ditch for treatment before leaving the site. INFILTRATION SYSTEM 1 Drainage 2 Minimum rrea required trrer 1 2 3 4 eatment volume(Cu ft) 4530 cf I 1786 cf I 13678 cf I 24394 cf I 5 16727 cf I GENERAL MDC FROM 02H.1050 3 Is the SCM sized to treat the SW from all surfaces at build-out? Yes Yes Yes Yes Yes 4 Is the SCM located away from contaminated soils? Yes Yes Yes Yes Yes 5 What are the side slopes of the SCM(H:V or enter"Vertical"for trenches)? 3:1 3:1 3:1 3:1 3:1 6 Does the SCM have retaining walls,gabion walls or other engineered side slopes? No No No No No 7 Are the inlets,outlets,and receiving stream protected from erosion (10-year storm)? Yes Yes Yes Yes Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume'? Yes Yes Yes Yes Yes 9 What is the method for dewatering the SCM for maintenance? Other Other Other Other Other 10 If applicable,will the SCM be cleaned out after construction? Yes Yes Yes Yes Yes 11 Does the maintenance access comply with General MDC(8)? Yes Yes Yes Yes Yes 12 Does the drainage easement comply with General MDC(9)? Yes Yes Yes Yes Yes If the SCM is on a single family lot,does(will?)the plat comply with 13 General MDC(10)? N/A N/A N/A N/A N/A 14 Is there an O&M Agreement that complies with General MDC(11)? Yes Yes Yes Yes Yes 15 Is there an O&M Plan that complies with General MDC(12)? Yes Yes Yes Yes Yes 16 Does the SCM follow the device specific MDC? Yes Yes Yes Yes Yes 17 Was the SCM designed by an NC licensed professional? Yes Yes Yes Yes Yes INFILTRATION SYSTEM MDC FROM 02H.1051 11 18 Proposed slope of the subgrade surface(%) 1% 1% 1% 1% 1% 19 Are terraces or baffles provided? No No No No No 20 Type of pretreatment: Forebay Forebay Forebay Forebay Forebay Soils Data _ 21 Was the soil investigated in the footprint and at the elevation of the infiltration system? No No No No No 22 SHWT elevation(fmsl) below 585.0 below 581.4 below 537.5 below 540.3 521.05 23 Depth to SHWT per soils report(in) 36.00 144.00 204.00 180.00 120.00 24 Ground elevation at boring in soils report(fmsl) 588.00 593.40 554.80 555.30 531.05 25 Is a detailed hydrogeologic study attached if the separation is between 1 and 2 feet? N/A N/A N/A N/A N/A 26 Soil infiltration rate(in/hr) 1.42 1.42 1.42 1.42 1.42 27 Factor of safety(FS)(2 is recommended): 2.00 2.00 2.00 2.00 2.00 Elevations 29 Bottom elevation(fmsl) 585.00 ft 585.00 ft 550.25 ft 549.25 ft 530.75 ft 30 Storage elevation(fmsl) 587.00 ft 587.50 ft 552.75 ft 551.75 ft 552.75 ft 31 Bypass elevation(fmsl) 588.50 ft 588.50 ft 553.70 ft 552.70 ft 533.65 ft For Basins Only 32 Bottom surface area(ft) 300 ft 252 ft 800 ft 1250 ft 1000 ft 33 Storage elevation surface area(ftu) 300.ft 252.ft 800.ft 1250.ft 1000.ft For Trenches Only 34 Length(ft) 35 Width(ft) 36 Perforated pipe diameter,if applicable(inches) 37 Number of laterals 38 Total length of perforated piping 39 Stone type,if applicable 40 Stone porosity(%( 41 Is stone free of fines? 42 Is the stone wrapped in geotextile fabric? 43 Has at least one inspection port been provided? Volumes/Drawdown 44 Design volume of SCM(cu ft) 4630 cf I 2187 cf 13880 cf 24517 cf 16757 cf 45 Time to draw down(hours) 114 hrs 72 hrs 108 hrs 114 hrs 114 hrs ADDITIONAL INFORMATION 46 Please use this space to provide any additional information about the infiltration system(s): Infiltration 1 2:25 PM 3/19/2024 SAND FILTER 1 Drainage area number 1 2 3 4 2 Minimum required treatment volume(cu ft) 436 sf 479 sf 436 sf 436 sf GENERAL MDC FROM 02H.1050 31 Is the SCM sized to treat the SW from all surfaces at build-out? Yes Yes Yes Yes 4 Is the SCM located away from contaminated soils? Yes Yes Yes Yes 5 What are the side slopes of the SCM(H:V)? 3:1 3:1 3:1 3:1 6 Does the SCM have retaining walls,gabion walls or other No No No No engineered side slopes? 7 Are the inlets,outlets,and receiving stream protected from erosion Yes Yes Yes Yes (10-year storm)? 8 Is there an overflow or bypass for inflow volume in excess of the Yes Yes Yes Yes design volume? 9 What is the method for dewatering the SCM for maintenance? Drawdown Orifice Drawdown Orifice Drawdown Orifice Drawdown Orifice 10 If applicable,will the SCM be cleaned out after construction? Yes Yes Yes Yes 11 Does the maintenance access comply with General MDC(8)? Yes Yes Yes Yes 12 Does the drainage easement comply with General MDC(9)? Yes Yes Yes Yes 13 If the SCM is on a single family lot,does(will?)the plat comply with N/A N/A N/A N/A General MDC(10)? 14 Is there an O&M Agreement that complies with General MDC(11)? Yes Yes Yes Yes 15 Is there an O&M Plan that complies with General MDC(12)? Yes Yes Yes Yes 16 Does the SCM follow the device specific MDC? Yes Yes Yes Yes 171 Was the SCM designed by an NC licensed professional? Yes Yes Yes Yes SAND FILTER MDC FROM 02H.1056 ' 18'SHWT elevation(fmsl) N/A Fill N/A Fill N/A Fill N/A Fill 19 Type of sand filter(open or closed) Open Open Open Open 20 If closed,will the filter will be pre-cast or pour-in-place? 21 If closed,top of grate elevation(fmsl) 22 Is this sand filter designed to attenuate peak flows? Yes Yes Yes Yes Sediment Chamber 23 Volume that can be retained in the sediment chamber(cubic feet) 88 cf 84 cf 130 cf 176 cf 24 Will there be a permanent pool in the sediment chamber? Yes Yes Yes Yes 25 Bottom of the sediment chamber(fmsl) 588.00 588.00 581.00 581.00 26 Area of the sediment chamber(square feet) 513 sf 381 sf 839 sf 821 sf 27 Physical depth of the sediment chamber(inches) 12 in 12 in 12 in 12 in 28 Ponding depth in the sediment chamber,above any permanent in in in in pool(inches) 29 Elevation of top of weir between chambers(fmsl) 589 589 582 582 Sand Chamber 30 Volume that can be retained in the sand chamber(cubic feet) 120 cf 120 cf 120 cf 120 cf 31 Bottom of the sand chamber(fmsl) 585.50 585.50 578.50 578.50 32 Area of the sand chamber(square feet) 60 sf 60 sf 60 sf 60 sf 33 Physical depth of the sand chamber(inches) 24 in 24 in 24 in 24 in 34 Ponding depth in the sand chamber,above the sand surface 12 in 13 in 15 in 16 in (inches) 35 Elevation of the bypass device(fmsl) 588.55 588.6 581.75 581.85 36 Type of bypass device Orifice-OCS Orifice-OCS Orifice-OCS Orifice-OCS 37 Mechanism for distributing flow over the sand surface Riprap Berm Riprap Berm Riprap Berm Riprap Berm 38 Sand specification for sand chamber _ Concrete _ Concrete Concrete _ Concrete 39 Depth above underdrain pipe(inches) 24 in 24 in 24 in 24 in 40 Will the media be maintained to drain at least two inches per hour at Yes Yes Yes Yes the sand surface? 41 Is at least one clean-out pipe provided at the low point of each Yes Yes Yes Yes underdrain line? 42 Will clean-out pipes be cap ed? Yes Yes Yes Yes ADDITIONAL INFORMATION 43 Please use this space to provide any additional information about the sand filter(s): Treatment for Roadway not able to drain to Infiltration Basins Sand Filter 1 2:27 PM 3/19/2024