The URL can be used to link to this page

Home My WebLink AboutSW6221101_Supplement-EZ Form_20230818 SUPPLEMENT-EZ COVER PAGE FORMS LOADED PROJECT INFORMATION Project Name Fort Bragg Technical Support Annex, PN79439.2 2 Project Area (ac) 15.16 3 Coastal Wetland Area (ac) 0 4 Surface Water Area (ac) 0 5 Is this project High or Low Density? High 6 Does this project use an off-site SCM? No COMPLIANCE WITH 02H .1003(4) I 7 Width of vegetated setbacks provided (feet) 30 8 Will the vegetated setback remain vegetated? N/A 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 4 13 Wet Pond 14 Stormwater Wetland 15 Permeable Pavement 16 Sand Filter 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: Lorraine Roberts, PE - Civil Engineer 28 Organization: Exp Federal, Inc. 29 Street address: 205 N Michigan Ave., Suite 3800 30 City, State, Zip: Chicago, IL 60601 31 Phone number(s): 312-616-3309 32 Email: Lorraine.Roberts@expfederal.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 ''„ OSA-r 0 F�sS i° C/1/ o 4' �< S Signature of Designer 046:49 ttiv+ / i I I/ 2 rN22- Q. • NER 7/15/2023 Seal Date DRAINAGE AREAS 1 Is this a high density project? Yes 2 If so, number of drainage areas/SCMs 5 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 4 Type of SCM Bioretention A Bioretention B5 Bioretention B4 Bioretention B3 Bypass 5 Total drainage area (sq ft) 722517 421487 57336 36539 50100 157055 6 Onsite drainage area (sq ft) 660203 364781 51728 36539 50100 157055 7 Offsite drainage area (sq ft) 62314 56706 5608 0 0 0 8 Total BUA in project (sq ft) 329359 sf 237757 sf 31155 sf 24840 sf 35607 sf sf New BUA on subdivided lots (subject to 9 permitting) (sq ft) sf sf sf sf sf sf New BUA not on subdivided lots (subject to 10 permitting) (sf) 329359 sf 237757 sf 31155 sf 24840 sf 35607 sf sf 11 Offsite BUA (sq ft) sf sf sf sf sf sf 12 Breakdown of new BUA not on subdivided lots: - Parking (sq ft) 116629 sf 25027 sf 31155 sf 24840 sf 35607 sf sf - Sidewalk (sq ft) 1733 sf 1733 sf sf sf sf sf _ - Roof(sq ft) 25222 sf _ 25222 sf sf sf sf sf - Roadway (sq ft) 31897 sf 31897 sf sf sf sf sf - Future (sq ft) sf sf sf sf sf sf - Other, please specify in the comment box below (sq ft) 153878 sf 153878 sf sf sf sf sf New infiltrating permeable pavement on 13 subdivided lots (sq ft) sf sf sf sf sf sf New infiltrating permeable pavement not on 14 subdivided lots (sq ft) sf sf sf sf sf sf Existing BUA that will remain (not subject to 15 permitting) (sq ft) sf sf sf sf sf sf 16 Existing BUA that is already permitted (sq ft) sf sf sf sf sf sf 17 Existing BUA that will be removed (sq ft) 152178 sf 90848 sf 23311 sf 14434 sf 4957 sf 18628 sf 18 Percent BUA _ 50% 56% 71% 68% 71% 0% 19 Design storm (inches) 1.0 in 1.0 in 1.0 in 1.0 in 20 Design volume of SCM (cu ft) 19588 cf 2576 cf 2015 cf 2879 cf 21 Calculation method for design volume SIMPLE SIMPLE SIMPLE SIMPLE ADDITIONAL INFORMATION Please use this space to provide any additional information about the 22 drainage area(s): "Other" BUA for DA1 is the paved area around the building. Certain areas of the site bypass the pond, therefore the total site areas will not equal the sum of the pond areas. BIORETENTION CELL 1 Drainage area number 1 (A) 2 (B5) 3 (B4) 4 (B3) 2 Minimum required treatment volume (cu ft) 19588 cf 2576 cf 2015 cf 2879 cf GENERAL MDC FROM 02H .1050 A 3 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 engineered side slopes? No No No No Are the inlets, outlets, and receiving stream protected from erosion 7 (10-year storm)? Yes Yes Yes Yes Is there an overflow or bypass for inflow volume in excess of the 8 design volume? Yes Yes Yes Yes _ 9 What is the method for dewatering the SCM for maintenance? Pump (preferred) Pump (preferred) Pump (preferred) Pump (preferred)_ 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)? N/A N/A N/A N/A 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 14 Is there an O&M Agreement that complies with General MDC (11)? No No No No 15 Is there an O&M Plan that complies with General MDC (12)? No No No No 16 Does the SCM follow the device specific MDC? Yes Yes Yes Yes 17 Was the SCM designed by an NC licensed professional? Yes Yes Yes Yes BIORETENTION CELL MDC FROM 02H .1052 Mill 18 SHWT elevation (fmsl) 247.00 <247 <246 <245 19 Bottom of the bioretention cell (fmsl) 255.00 266.00 266.00 266.00 20 Ponding depth of the design storm (inches) 12 in _ 12 in 12 in 12 in 21 Surface area of the bioretention cell (square feet) 21300 sf 3783 sf 4656 sf 4656 sf 22 Design volume of SCM (cu ft) 22566 cf 4713 cf 5595 cf 5595 cf 23 Is the bioretention cell used for peak attenuation? Yes No No No 24 Depth of peak attenuation over planting surface (in) 24 in _ N/A N/A N/A 25 Height of peak attenuation outlet above the planting surface (in) 18 in N/A N/A N/A 26 Infiltration rate of the in situ soil (inch/hour) in/hr in/hr in/hr in/hr 27 Diameter of the underdrain pipes (if applicable) 6 in 4 in 4 in 4 in 28 Does the design include Internal Water Storage (IWS)? Yes Yes Yes Yes 29 if so, elevation of the top of the IWS (fmsl) 253.5 264.5 264.5 264.5 30 Elevation of the planting surface (fmsl) 255 266 266 266 31 What type of vegetation will be planted? (grass, trees/shrubs, other)? Grass _ Grass Grass Grass 32 Media depth (inches) 30 in 30 in 30 in 30 in 33 Percentage of medium to coarse washed sand by volume 85% 85% 85% 85% _ 34 Percentage of fines (silt and clay) by volume 10% 10% 10% 10% 35 Percentage of organic matter by volume 5% _ 5% 5% 5% 36 Type of organic material Pine Bark Fines Pine Bark Fines Pine Bark Fines Pine Bark Fines 37 Phosphorus Index (P-Index) of media (unitless) 10 10 10 10 38 Will compaction be avoided during construction? Yes Yes Yes Yes 39 Will cell be maintained to a one inch/hour standard? Yes Yes Yes Yes 40 Depth of mulch, if applicable (inches) N/A N/A N/A N/A 41 Type of mulch, if applicable N/A N/A N/A N/A 42 How many clean out pipes are being installed? 4 4 4 4 43 Type of pretreatment that will be used: Forebay Grass/Gravel Grass/Gravel Grass/Gravel ADDITIONAL INFORMATION * II Please use this space to provide any additional information about 44 [the bioretention cell(s): Surface area is considered to be the area of the bottom of the pond. Volume accounts for 3:1 sideslopes. Items 12, 14, & 15 are not necessary at Fort Bragg. Fort Bragg has a standard O&M program for the entire base. Bioretention 3 10:40 AM 8/10/2023