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Home My WebLink AboutSW3220402_Supplement-EZ Form_20220627SUPPLEMENT-EZ COVER PAGE LOAD SUPPLEMENT FORMS (PROJECT INFORMATION Name Area (ac) Wetland Area Water Area (z at Granite Quarry - Phase 2 58.27 ac (Phase 2) 0 ac 2.50 ac 5 1 Is this project High or Low Density? High 6 1 Does this project use an off -site SCM? No COMPLIANCE WITH 02H .1003(4) 7 Width of vegetated setbacks provided (feet) 30 ft 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 lis streambank stabilization proposed on this project? Yes NUMBER AN SCMs: 11 Infiltration System 12 Bioretention Cell 13 Wet Pond 1 14 Stormwater Wetland 15 Permeable Pavement 16 Sand Filter 1 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 1 Filterra LOAD SUPPLEMENT FORMS SIGNER CERTIFICATION 27 Name and Title: Hy V. Nguyen, PE 28 Organization: DPR Associates, Inc 29 Street address: 420 Hawthorne Lane 30 City, State, Zip: Charlotte, NC 28204 31 1 Phone number(s): 704.332.1204 32 Email: hnguyen@dprassociates.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. G A �,sSo° SEAL 030523 ., y°•o�INE�o � V11rNmU��\\\\`�� Seal f � Signature of Designer 02-19-2021 Date DRAINAGE AREAS 1 Is this a high density project? Yes 2 If so, number of drainage areas/SCMs 3 3 Does this project have low density areas? No 4 If so, number of low density drainage areas 0 5 Is all/part of this project subject to previous rule versions? No FORMS LOADED DRAINAGE AREA INFORMATION Entire Site 1 2 3 4 Type of SCM Total Phase 2 Wet Pond 7 Sand Filter 8 Bypass 5 Total drainage area (sq ft) 2,435,439 989,247 274,428 1,171,764 6 Onsite drainage area (sq ft) 2,429,341 989,247 268,330 1,171,764 7 Offsite drainage area (sq ft) 6,098 0 6,098 0 8 Total BUA in project (sq ft) 599,481 455,597 113,634 30,250 9 New BUA on subdivided lots (subject to permitting) (sq ft) 370,920 303,890 67,030 0 10 New BUA not on subdivided lots (subject to permitting) (so 228,561 151,707 46,604 30,250 11 Offsite BUA (sq ft) 0 0 0 0 12 Breakdown of new BUA not on subdivided lots: ----- ----- ----- ----- Parking (sq ft) 1,597 0 0 1,597 Sidewalk (sq ft) 55,718 36,550 11,600 7,568 Roof (sq ft) 0 0 0 0 Roadway (sq ft) 154,150 100,545 32,520 21,085 Future (sq ft) 0 0 0 0 Other, please specify in the comment box below (sq ft) 17,096 14,612 2,484 0 13 New infiltrating permeable pavement on subdivided lots (sq ft) 0 0 0 0 14 New infiltrating permeable pavement not on Isubdivided lots (sq ft) 0 0 0 0 15 Existing BUA that will remain (not subject to permitting) (sq ft) 0 0 0 0 16 Existing BUA that is already permitted (sq ft) 0 0 0 0 17 Existing BUA that will be removed (sq ft) 0 0 0 0 18 Percent BUA 23.6% 46.05% 41.41 % 2.58% 19 Design storm (inches) 1.0 in 1.0 in 1.0 in 20 Design volume of SCM (cu ft) 40,121 cf 7,250 cf 21 Calculation method for design volume Simple Method Simple Method ADDITIONAL INFORMATION 22 Please use this space to provide any additional information about the drainage area(s): BMP 7 2,840 sf (Proposed Turn Around) + 11,772 sf (driveway within ROW) BMP 8 2,484 sf (driveway within ROW) WET POND area number MDC FROM 02H .1050 3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes 4 Is the SCM located away from contaminated soils? Yes 5 What are the side slopes of the SCM (H:V)? 3:1 6 Does the SCM have retaining walls, gabion walls or other engineered side slopes? No 7 Are the inlets, outlets, and receiving stream protected from erosion (10-year storm)? Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume? Yes 9 What is the method for dewatering the SCM for maintenance? Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? Yes 11 Does the maintenance access comply with General MDC (8)? Yes 12 Does the drainage easement comply with General MDC (9)? Yes 13 If the SCM is on a single family lot, does (will?) the plat comply with General MDC 10 ? N/A 14 Is there an O&M Agreement that complies with General MDC (11)? Yes 15 Is there an O&M Plan that complies with General MDC (12)? Yes 16 Does the SCM follow the device specific MDC? Yes 17 Was the SCM designed by an NC licensedprofessional? Yes WET POND MDC FROM 02H .1053 18 Sizing method used SA/DA 19 Has a stage/storage table been provided in the calculations? Yes 20 Elevation of the excavated main pool depth (bottom of sediment removal) (fmsl 713.50 21 Elevation of the main pool bottom (top of sediment removal) (fmsl) 714.00 22 Elevation of the bottom of the vegetated shelf (fmsl) 721.00 23 Elevation of the permanent pool (fmsl) 721.50 24 Elevation of the top of the vegetated shelf (fmsl) 722.00 25 Elevation of the temporary pool (fmsl) 723.04 26 Surface area of the main permanent pool (square feet) 16,653 27 Volume of the main permanent pool (cubic feet) 93,113 28 Average depth of the main pool (feet) 7.50 ft 29 Average depth equation used Equation 2 30 If using equation 3, main pool perimeter (feet) 311 If using equation 3, width of submerged veg. shelf (feet) 32 Volume of the forebay (cubic feet) 32,748 33 Is this 15-20% of the volume in the main pool? Yes 34 Clean -out depth for forebay (inches) 66 in 35 Design volume of SCM (cu ft) 40,121 36 Is the outlet an orifice or a weir? Orifice 37 If orifice, orifice diameter (inches) 4 in 381 If weir, weir height (inches) 39 If weir, weir length (inches) 40 Drawdown time for the temporary pool (days) 3.83 41 Are the inlet(s) and outlet located in a manner that avoids short- circuiting? Yes 42 Are berms or baffles provided to improve the flow path? Yes 43 Depth of forebay at entrance (inches) 74 in 441 Depth of forebay at exit (inches) 66 in 45 Does water flow out of the forebay in a non -erosive manner? Yes 46 Width of the vegetated shelf (feet) 6 ft 47 Slope of vegetated shelf (H:V) 6:1 48 Does the orifice drawdown from below the top surface of the permanent pool? No 49 Does the pond minimize impacts to the receiving channel from the 1- yr, 24-hr storm? Yes 50 Are fountains proposed? (If Y, please provide documentation that MDC 9 is met. No 51 Is a trash rack or other device provided to protect the outlet system? Yes 52 Are the dam and embankment planted in non -clumping turf grass? Yes 53 Species of turf that will be used on the dam and embankment sweet flag 541 Hasa plantinq plan been provided for the vegetated shelf? Yes ADDITIONAL INFORMATION 55 Please use this space to provide any additional information about the wet pond(s): SAND FILTER MDC FROM 02H .1050 3 Is the SCM sized to treat the SW from all surfaces at build -out? Y-es 4 Is the SCM located away from contaminated soils? Yes 5 What are the side slopes of the SCM (H:V)? 3:1 6 Does the SCM have retaining walls, gabion walls or other engineered side slopes? No 7 Are the inlets, outlets, and receiving stream protected from erosion (10-year storm)? Yes 8 Is there an overflow or bypass for inflow volume in excess of the design volume? Yes 9 What is the method for dewatering the SCM for maintenance? Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? Yes 11 Does the maintenance access comply with General MDC (8)? Yes 12 Does the drainage easement comply with General MDC (9)? Yes 13 If the SCM is on a single family lot, does (will?) the plat comply with General MDC 10 ? N/A 14 Is there an O&M Agreement that complies with General MDC (11)? Yes 151 Is there an O&M Plan that complies with General MDC (12)? Yes 161 Does the SCM follow the device specific MDC? Yes 17 Was the SCM desi ned b an NC licensed rofessional? Yes SAND FILTER MDC FROM 02H .1056 18 SHWT elevation (fmsl) 718.81 19 Type of sand filter (open or closed) 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 I Sediment Chamber 23 Volume that can be retained in the sediment chamber (cubic feet) 7,250 24 Will there be a permanent pool in the sediment chamber? No 25 Bottom of the sediment chamber fmsl 731.00 26 Area of the sediment chamber (square feet 8,228 27 Physical depth of the sediment chamber inches 24 in 28 Ponding depth in the sediment chamber, above any permanent pool inches 16 in 29 Elevation of top of weir between chambers (fmsl) 734 ISand Chamber 30 Volume that can be retained in the sand chamber (cubic feet) 31 Bottom of the sand chamber fmsl 32 Area of the sand chamber(square feet 40,810 731.00 1000 sf 33 Physical de th of the sand chamber inches 24 in 34 Ponding depth in the sand chamber, above the sand surface inches 24 in 351 Elevation of the bypass device (fmsl) 36 Type of bypass device 37 Mechanism for distributing flow over the sand surface 38 Sand specification for sand chamber ASTM C-33 Medium 39 Depth above underdrain pipe (inches) 40 Will the media be maintained to drain at least two inches per hour at the sand surface? Yes 41 Is at least one clean -out pipe provided at the low point of each underdrain line? Yes 42 Will clean -out pipes be capped? Yes ADDITIONAL INFORMATION 43 Please use this space to provide any additional information about the sand filter(s):