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Home My WebLink AboutSW1221003_Supplement-EZ Form_20221031SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION 1 Project Name Mills River Townhomes single-family Attached Development 2 Project Area (ac) 37,001 3 F5 Coastal Wetland Area (ac 0.000 4 Surface Water Area ac 0.194 Is this project High or Low Density? Nigh 6 Does this project use an off -site SCM? No COMPLIANCE WITH 02H A 003(4) 7 Width of vegetated setbacks provided (feet) 0 8 Will the vegetated setback remain vegetated? NIA 9 If BUA is proposed in the setback, does it meet NCAC 02H.1003(4)(c-d ? NIA 10 Is streambank stabilization proposed on this project? No UMBER AND TYPE OF SC Ms: 11 Infiltration System 12 Bioretention Cell 13 Wet Pond 14 Stormwater Wetland 15 Permeable Pavement 16 Sand Filter 17 Rainwater Harvesting RWH 18 Green Roof 19 LevelSpreader-Filter StriLS-FS 20 Disconnected Impervious Surface DIS 21 Trealment Swale 22 Dry Pond 23 Stormfilter 24 Silva Cell 25 Ba filter 3 26 IFilterra FORMS LOADED DESIGNER CERTIFICATION 27 Name and Title: Mark Brooks, PE 28 Organization: Brooks En i neering Associates PA 29 Street address: 15 Artlington Street 30 City, State, Zip: Asheville NC 28801 31 Phone numbers ; 828-232-4700 32 Email: mbrooks@brooksea.com Certification Statement: I certify, under penally of law that this Supplement-EZ form and all supporting information were prepared under my directlon 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 informatics are consistent with the information provided here. Signature of Designer 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 Ba Filter Ba Filter Ba Filter Ba Filter 5 Total drainage area (sq ft 529861 cf 229334 158200 142327 6 Onsite drainage area (sq ft) 529861 cf 229334 158200 142327 7 Offsite drainage area (sq ft cf 0 0 0 8 Total BUA in project (sq ft 374003 cf 147233 sf 126899 sf 99871 sf 9 New BUA on subdivided lots (subject to permitting) (sq ft 208076 cf 66204 sf 83145 sf 58727 sf 10 New BUA not on subdivided lots (subject to permitting) (so 138523 cf 53625 sf 43754 sf 41144 sf 11 Offsite BUA (sq ft cf sf sf sf 12 Breakdown of new BUA not on subdivided lots: cf 0 0 0 Parking (sq ft cf sf sf sf Sidewalk (sq ft cf sf sf sf Roof (sq ft cf sf sf sf Roadway (sq ft) 122546 cf 53625 sf 43751 sf 25170 sf Future (sq ft cf sf sf Other, please specify in the comment box below (sq ft) 15974 cf sf sf 15974 sf 13 New infiltrating permeable pavement on subdivided lots (sq ft cf sf sf sf 14 New infiltrating permeable pavement not on Isubdivided lots (sq ft cf sf sf sf 15permitting) Existing BUA that will remain (not subject to s ft cf sf sf sf 16 Existing BUA that is already permitted (sq ft) cf sf sf sf 17 Existing BUA that will be removed (sq ft 3126 cf 3126 sf sf sf 18 Percent BUA - 64% 80% 70% 19 Design storm inches - 1.8 in 1.5 in 2.2 in 20 Design volume of SCM cu ft 30258 cf 11998 cf 10177 cf 8083 cf 21 1 Calculation method for design volume Simple Simple Simple Simple ADDITIONAL INFORMATION 22 Please use this space to provide any additional information about the drainage area(s): The amenities BUA is listed for "Other" on Item #12 for Breakdown of new BUA not on subdivised lots. All offsite drainage areas are proposed to be bypass the SCM's BAYFILTER 1 1 Drainage area number 1 2 3 21 Minimum required treatment volume cu ft 11998 cf 10177 cf 8083 cf GENERAL MDC FROM 02H .1050 3 Is the SCM sized to treat the SW from all surfaces at build -out? Yes Yes Y-es 4 Is the SCM located away from contaminated soils? Yes Yes Yes 5 What are the side slopes of the SCM (H:V)? N/A N/A N/A 6 Does the SCM have retaining walls, gabion walls or other engineered side slopes? No No No 7 Are the inlets, outlets, and receiving stream protected from erosion 10- ear storm)? Yes Yes Yes 8 Is there an overflow or bypass for inflow volume in excess of the desi n volume? Yes Yes Yes 9 What is the method for dewatering the SCM for maintenance? Pump (preferred) Pump (preferred) Pump (preferred) 10 If applicable, will the SCM be cleaned out after construction? N/A N/A N/A 11 Does the maintenance access comply with General MDC (8)? Yes Yes Yes 12 Does the drainage easement comply with General MDC (9)? Yes Yes Yes 13 If the SCM is on a single family lot, does (will?) the plat comply with General MDC (10)? Yes Yes Yes 14 Is there an O&M Agreement that complies with General MDC (11)? Yes Yes Yes 15 Is there an O&M Plan that complies with General MDC (12)? Yes Yes Yes 16 Does the SCM follow the device specific MDC? Yes Yes Yes 17 Was the SCM designed by an NC licensedprofessional? Yes Yes Yes BAYFLILTER MDC FROM THE STORMWATER DESIGN MANUAL 18 If Volume Design is used, what is the volume from the drainage area (cubic feet)? 12061 cf 10188 cf 8085 cf 19 Is an upstream detention used? Yes Yes Yes 20 Volume of the upslope detention system (cubic feet) 3410 cf 4386 cf 3700 cf 21 Percent of the design volume contained in the upslope detention system % If Rate Based Sizing is used, for 1 inch or 1.5 inch (Coastal areas). Water Qualit flow rate for draina a area cfs Number of cartridges Cartridge height (inches) 69% 73% 71 % 22 2.76 cfs 1.18 cfs 59 cfs 231 28 12 6 24 36 in 36 in 36 in 25 SHWT elevation (fmsl) 2075.0 2072.0 2072.0 26 Elevation of bottom of BayFilter vault (fmsl) 2077.0 2074.0 2074.0 27 Clearance from the SHWT (feet) 2 ft 2 ft 2 ft 28 BayFilter Media Flow Rate (GPM/ft2 of Media Surface) .5 gpm/sf .5 gpm/sf .5 gpm/sf 29 Does the system includes a sediment sump? No No No 301 If yes, the diameter of the sump (feet) 31 If yes, the depth of the sump (feet) 32 Time to drain the sump (hours) 33 Time to drain the BayFilter (hours) 30 hrs 30 hrs 30 hrs 34 Is an off-line flow splitting device used? Yes Yes Yes 35 Type of media used (EMC or GAC-metals) EMC EMC EMC 36 Will maintenance be performed by Certified Maintenance Providers per instructions? Yes Yes Yes DITIONAL INFORMATI 37 Please use this space to provide any additional information about the BayFilter system(s):