Wingate University Student Housing Apartments - Sand Filter Supplemental Form

SAND FILTER1 Drainage area number1 Total coastal wetlands area (sq ft) sf - Parking / driveway (sq ft)115300 sfTotal surface water area (sq ft) sf - Sidewalk (sq ft)N/ATotal drainage area (sq ft)235200 sf - Roof (sq ft)29300 sfBUA associated with existing development (sq ft) 80150 sf - Roadway (sq ft)N/AProposed new BUA (sq ft)64500 sf - Other, please specify in the comment box below (sq ft) N/A Percent BUA of drainage area62%Total BUA (sq ft)144600 sfDesign rainfall depth (in)1.0 inMinimum volume required (cu ft) 8870 cfDesign volume of SCM (cu ft)9192 cf#1 Is the SCM sized to treat the SW from all surfaces at build-out? yes#7 If applicable, with the SCM be cleaned out after construction?yes#2 Is the SCM located on or near contaminated soils? no#8 Does the mainetenance access comply with General MDC (8)?Yes#3 What are the side slopes of the SCM (H:V)? :1#9 Does the drainage easement comply with General MDC (9)?Yes#3 Does the SCM have retaining walls, gabion walls or other engineered side slopes? no#10 If the SCM is on a single family lot, does the plat comply with General MDC (10)?No#4 Are the inlets, outlets, and receiving stream protected from erosion (10-year storm)? yes#11 Is there an O&M Agreement that complies with General MDC (11)?Yes#5 Is there a a bypass for flows in excess of the design flow? yes#12 Is there an O&M Plan that complies with General MDC (12)?Yes#6 What is the method for dewatering the SCM for maintenance?Other#13 Was the SCM designed by an NC licensed professional?Yes #1 SHWT elevation (fmsl)below 528 #3 Volume of stormwater from drainage area during design storm (cubic feet) 8870 cf#1 Type of sand filter (open or closed) open #3 Total volume that can be stored above the sediment and sand chambers (cubic feet) 9192 cf#1 If closed, describe if the filter will be pre-cast or pour-in-place: #3 Is this sand filter designed to attenuate peak flows? No#3 Elevation of the bypass device (fmsl) 535.5#1 If closed, top of grate elevation (fmsl) N/A#2 Volume that can be retained in the sediment chamber (cubic feet) N/A#2 Will there be a permanent pool in the sediment chamber? N/A#2 Bottom of the sediment chamber (fmsl)N/A#4 Ponding depth from the top of the sand to the bypass device (ft) 2.5#2 Area of the sediment chamber (square feet)N/A#2 Physical depth of the sediment chamber (inches) N/A#2 Ponding depth in the sediment chamber, above any permanent pool (inches)N/A#2 Elevation of top of weir between chambers (fmsl)N/A#2 Volume that can be retained in the sand chamber (cubic feet) N/A#2 Bottom of the sand chamber (fmsl) 531.5 sf #7 Depth above underdrain pipe (inches) 21 in#2 Area of the sand chamber (square feet)1406 sf#8 Will the media be maintained to drain at least two inches per hour at the sand surface? Yes#2 Physical depth of the sand chamber (inches) 18 in #9 Is at least one clean-out pipe provided at the low point of each underdrain line? Yes#2 Ponding depth in the sand chamber, above any permanent pool (inches)N/A#9 Will clean-out pipes be capped? YesWingate University Student HousingTHE DRAINAGE AREAGENERAL MDC FROM 02H .1050Break down of BUA in the drainage area (both new and existing):COMPLIANCE WITH THE APPLICABLE STORMWATER PROGRAMStormwater program(s) that apply (please specify):StatePlease use this space to provide any additional information about this sand filter that you think is relevant to the review:Sand filter design is an open sand filter in the bottom of a dry detention basin.SAND FILTER MDC FROM 02H .1056ADDITIONAL INFORMATIONSheet flow from interior basin weirs.N/A#3 Describe the bypass device:#5 Describe the mechanism for distributing flow over the sand surface:#6 Sand specification for sand chamber Washed concrete sand ASTM C33Outlet structure with multiple weirs.Sand Filter18:13 AM 1/17/2018