SW3231001_Supplement-EZ Form_20231219

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name McBride Subdvision
2 Project Area (ac) 84.2
3 Coastal Wetland Area (ac) 0
4 Surface Water Area (ac) 0.685
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) 30
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 1
14 Stormwater Wetland
15 Permeable Pavement
16 Sand Filter 1
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: Anthony Brent Cowan
28 Organization: The Isaacs Group, PC
29 Street address: 8720 Red Oak Blvd, Ste. 420
30 City, State, Zip: Charlotte, NC 28217
31 Phone number(s): 704.227.9402
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
B.
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08/22/2023
Seal Date

DRAINAGE AREAS
Is this a high density project?
1 TYes
2 If so, number of drainage areas/SCMs 2
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
4 Type of SCM Wet Pond Sand Filter
5 Total drainage area (sq ft) 1,965,863 _ 1,727,154 238,709
6 Onsite drainage area (sq ft) 1,965,863 1,727,154 238,709
7 Offsite drainage area (sq ft) 0 0
8 Total BUA in project (sq ft) 737,073 644953 sf 92120 sf
New BUA on subdivided lots (subject to
9 permitting) (sq ft) 486,000 418500 sf 67500 sf
New BUA not on subdivided lots (subject to
10 permitting) (sf) 251,073 226453 sf 24620 sf
11 Offsite BUA (sq ft) sf sf sf
12 Breakdown of new BUA not on subdivided lots:
- Parking (sq ft) 8,362 8362 sf _
- Sidewalk (sq ft) 64,884 58214 sf 6670 sf
- Roof(sq ft) 0
- Roadway (sq ft) 167,841 149891 sf 17950 sf
- Future (sq ft) 6,386 6386 sf sf
- Other, please specify in the comment box
below (sq ft) 3,600 3600 sf sf
New infiltrating permeable pavement on
13 subdivided lots (sq ft) _ sf sf sf
New infiltrating permeable pavement not on
14 subdivided lots (sq ft) sf sf sf
Existing BUA that will remain (not subject to
15 permitting) (sq ft) sf sf sf
16 Existing BUA that is already permitted (sq ft) sf sf sf
17 Existing BUA that will be removed (sq ft) 15912 sf 15912 sf
18 Percent BUA 38% 37% 39%
19 Design storm (inches) 1.0 in
20 Design volume of SCM (cu ft) 61399 cf 55483 cf 5916 cf
21 Calculation method for design volume — Note1 Note2
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
Note1: SCM #1 has been sized based on 4.37-ft average depth and SA/DA
ratio of 1.08 (85% TSS removal) SCM#1 temporary water quality storage
volume calculated using Rv equation. Note 2: SCM #2 temporary water
quality storage volume calculated using Rv equation. Note 3: BUA per lot is
A Inn of Thin .-Aron innli irlon Inn,inn 9 Q' %eiirlc rlrijiotnin‘i ')n'v')n' nnfin nnrl

WET POND
I Drainage area number _ 1
2 Minimum required treatment volume (cu ft) 55483 cf
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 No
engineered 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? 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
13 If the SCM is on a single family lot, does (will?) the plat comply with N/A
(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 desi ned b an NC licensed rofessional? Yes
WET POND MDC FROM 02H .1053
18 Sizing method used SA/DA
19 Has a stage/storage table been provided in the calculations? Yes
20 Elevation of the excavated main pool depth (bottom of sediment 630.00
removal) (fmsl)
21 Elevation of the main pool bottom (top of sediment removal) (fmsl) 631.00
22 Elevation of the bottom of the vegetated shelf(fmsl) 636.00
- 23 Elevation of the permanent pool (fmsl) 636.50
- 24 Elevation of the top of the vegetated shelf(fmsl) 637.00
- 25 Elevation of the temporary pool (fmsl) 637.27
- 26 Surface area of the main permanent pool (square feet) 68803
- 27 Volume of the main permanent pool (cubic feet) 55483 cf
- 28 Average depth of the main pool (feet) 4.37 ft
- 29 Average depth equation used Equation 3
30 If using equation 3, main pool perimeter (feet) 68803.0 ft
31 If using equation 3, width of submerged veg. shelf(feet) 3.0 ft
32 Volume of the forebay (cubic feet) _ 96932 cf
33 Is this 15-20% of the volume in the main pool? No
34 Clean-out depth for forebay (inches) _ 50 in
35 Design volume of SCM (cu ft) 260492 cf
36 Is the outlet an orifice or a weir? Orifice
37 If orifice, orifice diameter(inches) 4 in
38 If weir, weir height (inches)
39 If weir, weir length (inches)
- 40 Drawdown time for the temporary pool (days) _ 2.62
41 Are the inlet(s) and outlet located in a manner that avoids short- Yes
circuiting?
- 42 Are berms or baffles provided to improve the flow path? Yes
43 Depth of forebay at entrance (inches) 18 in
_- 44 Depth of forebay at exit (inches) _ 66 in
_ 45 Does water flow out of the forebay in a non-erosive manner? _ Yes
46 Width of the vegetated shelf(feet) 6 ft
47 Slope of vegetated shelf(H:V) _ 6:1
48 Does the orifice drawdown from below the top surface of the Yes
_ permanent pool?
49 Does the pond minimize impacts to the receiving channel from the 1- Yes
yr, 24-hr storm?
50 Are fountains proposed? (If Y, please provide documentation that No
MDC(9) is met.)
51 Is a trash rack or other device provided to protect the outlet system? Yes
52 Are the dam and embankment planted in non-clumping turf grass? Yes
53 Species of turf that will be used on the dam and embankment Fescue
54 Has a planting plan been provided for the vegetated shelf? Yes
ADDITIONAL INFORMATION
Please use this space to provide any additional information about
55 the wet pond(s):
Wet Pond 3 12:10 PM 8/22/2023

SAND FILTER
1 Drainage area number _ 2
2 Minimum required treatment volume (cu ft) 5916 sf
GENERAL MDC FROM 02H .1050
3 Is the SCM sized to treat the SW from all surfaces at build-out? Yet)
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
_ 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? Other
- 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 No
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 desi ned b an NC licensed rofessional? Yes
SAND FILTER MDC FROM 02H .1056
18 SHWT elevation (fmsl) not encontered
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) 3303 cf
- 24 Will there be a permanent pool in the sediment chamber? No
25 Bottom of the sediment chamber (fmsl) 636.50
26 Area of the sediment chamber (square feet) 2604 sf
27 Physical depth of the sediment chamber(inches) 3 in
28 Ponding depth in the sediment chamber, above any permanent na
pool (inches)
29 Elevation of top of weir between chambers (fmsl) 638.5
Sand Chamber
30 Volume that can be retained in the sand chamber (cubic feet) 14599 cf
31 Bottom of the sand chamber(fmsl) 636.00
32 Area of the sand chamber (square feet) 480 sf
33 Physical depth of the sand chamber (inches) 30 in
34 Ponding depth in the sand chamber, above the sand surface 54 in
(inches)
35 Elevation of the bypass device (fmsl) 640
36 Type of bypass device ocs spillway
37 Mechanism for distributing flow over the sand surface forebay berm
38 Sand specification for sand chamber astm c-33
39 Depth above underdrain pipe (inches) 18 in
40 Will the media be maintained to drain at least two inches per hour at r 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 i es be ca ed? Yes
ADDITIONAL INFORMATION
43 Please use this space to provide any additional information about
the sand filter(s):
Sand Filter 4 12:10 PM 8/22/2023