SW1240301_Supplement-EZ Form_20240319

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name Marketplace at Mills River
2 Project Area(ac) 16.43
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)
7 Width of vegetated setbacks provided(feet)
8 Will the vegetated setback remain vegetated?
9 If BUA is proposed in the setback,does it meet NCAC 02H.1003(4)(c-d)?
10 Is streambank stabilization proposed on this project?
NUMBER AND TYPE OF SCMs:
11 Infiltration System
12 Bioretention Cell
13 Wet Pond
14 Stormwater Wetland
15 Permeable Pavement
16 Sand Filter 1
17 Rainwater Harvesting(RWH)
18 Green Roof
19 Level Spreader-Filter Strip(LS:FS j__�
20 Disconnected Impervious Surface(DIS)
21 Treatment Swale
22 Dry Pond
23 Storm Filter
24 Silva Cell
25 Bayfilter 26 Filterra
FORMS LOADED
DESIGNER CERTIFICATION
27 Name and Title: Jennifer Losurdo,PE(Managing Partner)
28 Organization: Genesis Engineering Collaborative
29 Street address: 3360 Martin Farm Road,Suite 200
30 City,State,Zip: Suwanee,GA 30024
31 Phone number(s): I 470.375.2001
32 Email: [e-mail]
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
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DRAINAGE AREAS
1 Is this a high density project? Yes
2 If so,number of drainage areas/SCMs 1
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
4 Type of SCM Sand Filter
5 Total drainage area(sq ft) 14.19
6 Onsite drainage area(sq ft) 13.41
7 Offsite drainage area(sq ft) 0.78
8 Total BUA in project(sq ft) 435600 sf
New BUA on subdivided lots(subject to
9 permitting)(sq ft)
New BUA not on subdivided lots(subject to
10 permitting)(sf)
11 Offsite BUA(sq ft)
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft) 195856 sf
-Sidewalk(sq ft) 12025 sf
-Roof(sq ft) 61125 sf
-Roadway(sq ft) 173649 sf
-Future(sq ft) 160344 sf
-Other,please specify in the comment box
below(sq ft) 4141 sf
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)
16 Existing BUA that is already permitted(sq ft)
17 Existing BUA that will be removed(sq ft) 24330 sf
18 Percent BUA 71%
19 Design storm(inches) 1.0 in
20 Design volume of SCM(cu ft) 108644 cf
21 Calculation method for design volume SCS
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
-Other-BUA area for truck duck and other concrete pads.

SAND FILTER
1 Drainage area number 1
2 Minimum required treatment volume(cu ft) 26434 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
Does the SCM have retaining walls,gabion walls or other
6 engineered side slopes? No
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 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)?
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) 2092
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) 13444 cf
24 Will there be a permanent pool in the sediment chamber? No
25 Bottom of the sediment chamber(fmsl) 2095.00
26 Area of the sediment chamber(square feet) 2516 sf
27 Physical depth of the sediment chamber(inches) 108 in
28 Ponding depth in the sediment chamber,above any permanent 105 in
pool(inches)
29 Elevation of top of weir between chambers(fmsl) 2106
Sand Chamber
30 Volume that can be retained in the sand chamber(cubic feet) 13819 cf
31 Bottom of the sand chamber(fmsl) 2095.00
32 Area of the sand chamber(square feet) 2838 sf
33 Physical depth of the sand chamber(inches) 18 in
34 Ponding depth in the sand chamber,above the sand surface 44 in
(inches)
35 Elevation of the bypass device(fmsl) 2100.65
36 Type of bypass device orifce
37 Mechanism for distributing flow over the sand surface level spreader
38 Sand specification for sand chamber ASTM C-33
39 Depth above underdrain pipe(inches) 12 in
Will the media be maintained to drain at least two inches per hour at
40 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
Please use this space to provide any additional information about
43 the sand filter(s):
Sand Filter 3 12:15 PM 3/1/2024