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Home My WebLink AboutSW3221001_Supplement-EZ Form_20230628 SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION 1 Project Name Brighton Park 2 Project Area(ac) 85.71 3 Coastal Wetland Area(ac) 4 Surface Water Area(ac) 1.065 5 Is this project High or Low Density? Both High and Low Density 6 Does this project use an off-site SCM? No COMPLIANCE WITH 02H.1003(4) -=—=111 7 Width of vegetated setbacks provided(feet) 85 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)? N/A 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 6 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: Carlos L.Ruano,P.E. 28 Organization: Latham-Walters Engineering Inc. 29 Street address: 16507-A Norhcross Drive 30 City,State,Zip: Huntersville,NC 28078 31 Phone number(s): 704-895-8484 32 Email: carlos@lwengineer.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 \ oolt111111 / / =° °OFEssIO Gf, , 0Q �Y'9<oy : SEAL - Signature of Designer 0 52356 000. //''1l llllllll\\\\ 6/26/2023 Seal Date DRAINAGE AREAS 1 Is this a high density project? Yes 2 If so,number of drainage areas/SCMs 6 3 Does this project have low density areas? Yes 4 If so,number of low density drainage areas 2 Is all/part of this project subject to previous rule 5 versions? No FORMS LOADED DRAINAGE AREA INFORMATION Entire Site 1 2 3 4 4 Type of SCM Sand Filter Sand Filter Sand Filter Sand Filter Sand Filter 5 Total drainage area(sq ft) 3016093 794099 449975 386377 416434 6 Onsite drainage area(sq ft) 2933166 794099 449975 386377 416434 7 Offsite drainage area(sq ft) 101766 0 0 0 0 8 Total BUA in project(sq ft) 1336962 sf 387208 sf 192839 sf 171602 sf 188492 sf New BUA on subdivided lots(subject to permitting) 9 (sq ft) 836600 225600 sf 138650 sf 117500 sf 129250 sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 431071 161608 sf 54189 sf 54102 sf 59242 sf 11 Offsite BUA(sq ft) 47418 sf sf 12 Breakdown of new BUA not on subdivided lots: 0 -Parking(sq ft) 11530 11530 sf -Sidewalk(sq ft) 98707 32234 sf 14549 sf 12720 sf 13068 sf -Roof(sq ft) 21780 21780 sf -Roadway(sq ft) 299054 96063 sf 39640 sf 41382 sf 46174 sf -Future(sq ft) -Other,please specify in the comment box below(sq ft) New infiltrating permeable pavement on 13 subdivided lots(sq ft) New infiltrating permeable pavement not on 14 subdivided lots(sq ft) Existing BUA that will remain(not subject to 15 permitting)(sq ft) 47418 sf 16 Existing BUA that is already permitted(sq ft) 17 Existing BUA that will be removed(sq ft) 18 Percent BUA 36% 49% 43% 44% 45% 19 Design storm(inches) 1.0 in 1.0 in 1.0 in 1.0 in 1.0 in 20 Design volume of SCM(cu ft) 32349 cf 16338 cf 14480 cf 15872 cf 21 Calculation method for design volume Simple Method Simple Method Simple Method Simple Method Simple Method ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): DRAINAGE AREAS 1 Is this a high density project? Yes 2 If so,number of drainage areas/SCMs 6 3 Does this project have low density areas? Yes 4 If so,number of low density drainage areas 2 Is all/part of this project subject to previous rule 5 versions? No FORMS LOADED DRAINAGE AREA INFORMATION Entire Site 5 6 LD 1 LD 2 4 Type of SCM Sand Filter Sand Filter Sand Filter 5 Total drainage area(sq ft) 3016093 351529 432986 116740 67953 6 Onsite drainage area(sq ft) 2933166 351529 432986 65831 35935 7 Offsite drainage area(sq ft) 101766 0 0 50909 _ 32018 8 Total BUA in project(sq ft) 1336962 sf 136941 sf 190589 sf 49980 sf 19311 sf New BUA on subdivided lots(subject to permitting) 9 (sq ft) 836600 103400 sf 122200 sf New BUA not on subdivided lots(subject to 10 permitting)(sf) 431071 33541 sf 68389 sf 11 Offsite BUA(sq ft) 47418 sf 35666 sf 11752 sf 12 Breakdown of new BUA not on subdivided lots: 0 -Parking(sq ft) 11530 -Sidewalk(sq ft) 98707 8712 sf 17424 sf -Roof(sq ft) 21780 -Roadway(sq ft) 299054 24830 sf 50965 sf 14314 sf 7559 sf -Future(sq ft) -Other,please specify in the comment box below(sq ft) New infiltrating permeable pavement on 13 subdivided lots(sq ft) New infiltrating permeable pavement not on 14 subdivided lots(sq ft) Existing BUA that will remain(not subject to 15 permitting)(sq ft) 47418 sf 35666 sf 11752 sf 16 Existing BUA that is already permitted(sq ft) 17 Existing BUA that will be removed(sq ft) 18 Percent BUA 36% 39% 44% 22% 21 19 Design storm(inches) 1.0 in 1.0 in 1.0 in 20 Design volume of SCM(cu ft) 11735 cf 16098 cf 21 Calculation method for design volume Simple Method Simple Method Simple Method ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): LOW DENSITY DESIGN REQUIREMENTS FOR LOW DENSITY PROJECTS FROM 02H.1003 1 Is project below density thresholds set forth in the applicable stormwater rule? Yes 2 Does project maximize dispersed flow and minimize channelization of flow? Yes 3 Has the use of piping been minimized per.1003(2)(c)? Yes 4 Side slopes of the vegetated conveyances(H:V) 3:1 5 Maximum velocity in the vegetated conveyances during the 10-year storm? 1.28 6 Are curb outlet swales proposed? No 7 Maximum longitudinal slope of curb outlet swale(s)(%) 8 Bottom width of curb outlet swale(s)(feet) 9 Maximum side slope of curb outlet swale(s)(H:V) 10 Minimum length of curb outlet swale(s)(feet) 11 Are treatment swales used instead of curb outlet swales? No 12 Is stormwater released at the edge of the setback as dispersed flow? Yes 13 Have stormwater outlets been designed to prevent downslope erosion? Yes 14 Are variations to rule.1003 proposed? No ADDITIONAL INFORMATION 15 Please use this space to provide any additional information about this low density project: Drainage Pervious Swale Area BUA area C Q Slope Vaiia,., Vaaaai Flow depth # (ad (ac) (ad (cfs) (%) (fps) (fps) (ft) 1 2.68 0.33 2.35 0.60 11.67 2.00 6.00 1.28 1.55 2 1.06 0.00 0.00 0.60 4.62 2.00 6.00 1.01 1.01 3 0.61 0.00 0.00 0.60 2.66 2.00 6.00 0.86 0.78 4 0.57 0.00 0.00 0.60 2.48 2.00 6.00 0.85 0.75 5 0.38 0.17 0.21 0.60 1.66 2.00 6.00 0.75 0.62 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 SAND FILTER 1 Drainage area number 1 2 3 4 5 2 Minimum required treatment volume(cu ft) 24262 sf 12253 sf 10860 sf 11904 sf 8801 sf GENERAL MDC FROM 02H.1050 3 Is the SCM sized to treat the SW from all surfaces at build-out? Yco Yco 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)? 3:1 3:1 3:1 3:1 3:1 6 Does the SCM have retaining walls,gabion walls or other engineered No No No No No side slopes? 7 Are the inlets,outlets,and receiving stream protected from erosion Yes 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 Yes design volume? 9 What is the method for dewatering the SCM for maintenance? Drawdown Orifice I Drawdown Orifice Drawdown Orifice Drawdown Orifice Drawdown Orifice 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 13 If the SCM is on a single family lot,does(will?)the plat comply with Yes Yes Yes Yes Yes General MDC(10)? 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 SAND FILTER MDC FROM 02H.1056 I 18 SHWT elevation(fmsl) 606.79 627.61 623 623.71 607.23 19 Type of sand filter(open or closed) Open Open Open Open Open 20 If closed,will the filter will be pre-cast or pour-in-place? N/A N/A N/A N/A N/A 21 If closed,top of grate elevation(fmsl) N/A N/A N/A N/A N/A 22 Is this sand filter designed to attenuate peak flows? Yes I Yes Yes Yes Yes Sediment Chamber 23 Volume that can be retained in the sediment chamber(cubic feet) 19697 cf 14262 cf 11631 cf 12723 cf 9902 cf 24 Will there be a permanent pool in the sediment chamber? no no no no no 25 Bottom of the sediment chamber(fmsl) 611.00 633.00 628.00 631.00 613.00 26 Area of the sediment chamber(square feet) 8358 sf 8677 sf 5158 sf 5596 sf 4110 sf 27 Physical depth of the sediment chamber(inches) 24 in 18 in 24 in 24 in 24 in 28 Ponding depth in the sediment chamber,above any permanent pool 24 in 18 in 24 in 24 in 24 in (inches) 29 Elevation of top of weir between chambers(fmsl) 613 I 634.5 630 I 633 615 Sand Chamber 30 Volume that can be retained in the sand chamber(cubic feet) 16115 cf I 11669 cf 9516 cf 10410 cf 8102 cf 31 Bottom of the sand chamber(fmsl) 611.00 632.50 628.00 1 631.00 613.00 32 Area of the sand chamber(square feet) 6838 sf 7099 sf 4221 sf 4579 sf 3362 sf 33 Physical depth of the sand chamber(inches) 24 in 18 in 24 in 24 in 24 in 34 Ponding depth in the sand chamber,above the sand surface 24 in 18 in 24 in 24 in 24 in (inches) 35 Elevation of the bypass device(fmsl) 613 634 630 633 615 36 Type of bypass device Orifice Orifice Orifice Orifice Orifice 37 Mechanism for distributing flow over the sand surface Riprap Riprap Riprap Riprap Riprap 38 Sand specification for sand chamber ASTM C33 ASTM C33 ASTM C33 ASTM C33 ASTM C33 39 Depth above underdrain pipe(inches) 12 in 18 in 18 in 18 in 18 in 40 Will the media be maintained to drain at least two inches per hour at Yes 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 Yes underdrain line? _ 42 Will clean-out pipes be capped? Yes Yes Yes Yes Yes ADDITIONAL INFORMATION 43 Please use this space to provide any additional information about the sand filter(s): Sand Filter 5 2:54 PM 6/26/2023 SAND FILTER 1 Drainage area number 6 2 Minimum required treatment volume(cu ft) 12074 sf 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 13 If the SCM is on a single family lot,does(will?)the plat comply with Yes 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 SAND FILTER MDC FROM 02H.1056 18 SHWT elevation(fmsl) 606 19 Type of sand filter(open or closed) Open 20 If closed,will the filter will be pre-cast or pour-in-place? N/A 21 If closed,top of grate elevation(fmsl) N/A 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) 15808 cf 24 Will there be a permanent pool in the sediment chamber? no 25 Bottom of the sediment chamber(fmsl) 618.00 _ 26 Area of the sediment chamber(square feet) 6956 sf _ 27 Physical depth of the sediment chamber(inches) 24 in 28 Ponding depth in the sediment chamber,above any permanent pool 24 in (inches) 29 Elevation of top of weir between chambers(fmsl) 620 Sand Chamber _ 30 Volume that can be retained in the sand chamber(cubic feet) 12934 cf _ 31 Bottom of the sand chamber(fmsl) 618.00 _ 32 Area of the sand chamber(square feet) 5691 sf 33 Physical depth of the sand chamber(inches) 24 in 34 Ponding depth in the sand chamber,above the sand surface 24 in (inches) _ 35 Elevation of the bypass device(fmsl) 620 _ _ 36 Type of bypass device Orifice _ 37 Mechanism for distributing flow over the sand surface Riprap _ 38 Sand specification for sand chamber ASTM C33 _ 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): Sand Filter 6 2:54 PM 6/26/2023