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Home My WebLink AboutSW3240503_Supplement-EZ Form_20240612 SUPPLEMENT-EZ COVER PAGE LOAD SUPPLEMENT FORMS PROJECT INFORMATION 1 Project Name Aurora at Price Mill Creek 2 Project Area(ac) 79.5 3 Coastal Wetland Area(ac) N/A 4 Surface Water Area(ac) 2.17 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) 30 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 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 Filterra LOAD SUPPLEMENT FORMS DESIGNER CERTIFICATION 27 Name and Title: Danis E.Simmons,PE;Civil Engineering Director 28 Organization: ESP Associates,Inc. 29 Street address: 20484 Chartwell Center Drive,Suite D 30 City,State,Zip: Cornelius,NC 28031 31 Phone number(s): 704-990-9428 32 Email: dsimmons@espassociates.com 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 4/Y0 CAR LICENSE NO..• _ = t SEAL `••� Signatur of Designer F-1407 _ _ : 025775 = for E P Associates, Inc. %: : :• �•�•'........... ` i •• tom �� '/ Oiil ii ��``` ''�� i111 i t►�o�```` Date 05/13/24 Seal DRAINAGE AREAS 1 Is this a high density project? Yes 2 If so,number of drainage areas/SCMs _ 2 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 4 Type of SCM _ Wet Pond Sand Filter _ 5 Total drainage area(sq ft) 3470860.8 _ 918244.8 511394.4 6 Onsite drainage area(sq ft) 3470860.8 _ 918244.8 488401.4 7 Offsite drainage area(sq ft) 0 0 22993 8 Total BUA in project(sq ft) 381150 sf 230868 sf 150282 sf New BUA on subdivided lots(subject to 9 permitting)(sq ft) 184513 sf 111078 sf 73435 sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 196637 sf 119790 sf 76847 sf 11 Offsite BUA(sq ft) N/A N/A N/A 12 Breakdown of new BUA not on subdivided lots: N/A N/A N/A -Parking(sq ft) N/A N/A N/A -Sidewalk(sq ft) N/A N/A N/A -Roof(sq ft) N/A N/A N/A -Roadway(sq ft) N/A N/A N/A -Future(sq ft) N/A N/A N/A -Other,please specify in the comment box below(sq ft) N/A N/A N/A New infiltrating permeable pavement on 13 subdivided lots(sq ft) N/A N/A N/A New infiltrating permeable pavement not on 14 subdivided lots(sq ft) N/A N/A N/A Existing BUA that will remain(not subject to 15 permitting)(sq ft) N/A N/A N/A 16 Existing BUA that is already permitted(sq ft) N/A N/A N/A 17 Existing BUA that will be removed(sq ft) N/A N/A N/A 18 Percent BUA 5% 25% 29% 19 Design storm(inches) 1.0 in 1.0 in 1.0 in 20 Design volume of SCM(cu ft) 171763 cf 105357 cf 66406 cf 21 Calculation method for design volume N/A HRT Method Simple Method ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): WET POND I 1 Drainage area number 1 I 2 Minimum required treatment volume(Cu ft) 21609 cf GENERAL 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 No side slopes? 7 Are the inlets,outlets,and receiving stream protected from erosion Yes (10-year storm)? 8 Is there an overflow or bypass for inflow volume in excess of the Yes design volume? 9 What is the method for dewatering the SCM for maintenance? Drawdown Orifice 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 If the SCM is on a single family lot,does(will?)the plat comply with 13 N/A General MDC(10)? 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 licensed professional? Yes WET POND MDC FROM 02H.1053 18 Sizing method used HRT 19 Has a stage/storage table been provided in the calculations? Yes 20 Elevation of the excavated main pool depth(bottom of sediment 568.50 removal)(fmsl) 21 Elevation of the main pool bottom(top of sediment removal)(fmsl) 569.00 22 Elevation of the bottom of the vegetated shelf(fmsl) 573.00 23 Elevation of the permanent pool(fmsl) 573.50 24 Elevation of the top of the vegetated shelf(fmsl) 574.00 25 Elevation of the temporary pool(fmsl) 574.40 26 Surface area of the main permanent pool(square feet) 17980 27 Volume of the main permanent pool(cubic feet) 61033 cf 28 Average depth of the main pool(feet) 3.39 ft 29 Average depth equation used Equation 2 30 If using equation 3,main pool perimeter(feet) 31 If using equation 3,width of submerged veg.shelf(feet) 32 Volume of the forebay(cubic feet) 12230 cf 33 Is this 15-20%of the volume in the main pool? Yes 34 Clean-out depth for forebay(inches) 45 in 35 Design volume of SCM(cu ft) 105357 cf 36 Is the outlet an orifice or a weir? Orifice 37 If orifice,orifice diameter(inches) 3 in 38 If weir,weir height(inches) 39 If weir,weir length(inches) 40 Drawdown time for the temporary pool(days) 2.4 41 Are the inlet(s)and outlet located in a manner that avoids short- Yes circuiting? 42 Are berms or baffles provided to improve the flow path? No 43 Depth of forebay at entrance(inches) 66 in 44 Depth of forebay at exit(inches) 60 in 45 Does water flow out of the forebay in a non-erosive manner? Yes 46 Width of the vegetated shelf(feet) 10 ft 47 Slope of vegetated shelf(H:V) 10:1 48 Does the orifice drawdown from below the top surface of the No permanent pool? 49 Does the pond minimize impacts to the receiving channel from the 1- Yes yr,24-hr storm? 50 Are fountains proposed?(If Y,please provide documentation that No MDC(9)is met.) 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 Fescue 54 Has a planting 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): 2 SAND FILTER 1 Drainage area number 2 2 Minimum required treatment volume(cu ft) 10052 sf GENERAL MDC FROM 02H.1050 3 Is the SCM sized to treat the SW from all surfaces at build-out? Yen 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 No side slopes? 7 Are the inlets,outlets,and receiving stream protected from erosion Yes (10-year storm)? 8 Is there an overflow or bypass for inflow volume in excess of the Yes design volume? 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 If the SCM is on a single family lot,does(will?)the plat comply with 13 N/A General MDC(10)? 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 desi ned b an NC licensed rofessional? Yes SAND FILTER MDC FROM 02H.1056 18 SHWT elevation(fmsl) 569 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 Sediment Chamber 23 Volume that can be retained in the sediment chamber(cubic feet) 5265 cf 24 Will there be a permanent pool in the sediment chamber? No 25 Bottom of the sediment chamber(fmsl) 574.00 26 Area of the sediment chamber(square feet) 3470 sf 27 Physical depth of the sediment chamber(inches) 30 in 28 Ponding depth in the sediment chamber,above any permanent pool 30 in (inches) 29 Elevation of top of weir between chambers(fmsl) 576 Sand Chamber 30 Volume that can be retained in the sand chamber(cubic feet) 17735 cf 31 Bottom of the sand chamber(fmsl) 572.00 32 Area of the sand chamber(square feet) 900 sf 33 Physical depth of the sand chamber(inches) 42 in 34 Ponding depth in the sand chamber,above the sand surface 24 in (inches) 35 Elevation of the bypass device(fmsl) 575.5 36 Type of bypass device orifice 37 Mechanism for distributing flow over the sand surface sheet flow 38 Sand specification for sand chamber C-33 39 Depth above underdrain pipe(inches) 18 in 40 Will the media be maintained to drain at least two inches per hour at Yes the sand surface? _ 41 Is at least one clean-out pipe provided at the low point of each Yes underdrain line? 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): SHWT NOT ENCOUNTERED ABOVE THIS ELEVATION 2