SW3181002_Supplement-EZ Form_20240112

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1 Project Name Cottages West/Cottages at Indian Trail
2 Project Area(ac) 12.67
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) 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
13 Wet Pond
14 Stormwater Wetland
15 Permeable Pavement
16 Sand Filter 2
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: Nicholas T.Vesely,PE(Engineer)
28 Organization: V3 Southeast
29 Street address: 3700 South Boulevard,Suite 200
30 City,State,Zip: Charlotte,NC 28209
31 Phone number(s): 704.920.2883
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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Seal Date

DRAINAGE AREAS
1 Is this a high density project? Yes
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 _ Sand Filter Sand Filter _
5 Total drainage area(sq ft) 651480 _ 291422 360058
6 Onsite drainage area(sq ft) 434680 155496 279184
7 Offsite drainage area(sq ft) 216800 135926 80874
8 Total BUA in project(sq ft) 433706 sf 196664 sf 237042 sf
New BUA on subdivided lots(subject to
9 permitting)(sq ft) 173897 sf 44721 sf 129176 sf
New BUA not on subdivided lots(subject to
10 permitting)(sf) 43009 sf 16017 sf 26992 sf
11 Offsite BUA(sq ft) _ 216800 sf _ 135926 sf 80874 sf
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft)
-Sidewalk(sq ft)
-Roof(sq ft)
-Roadway(sq ft) 43009 sf 16017 sf 26992 sf
-Future(sq ft)
-Other,please specify in the comment box
below(sq ft) 874 sf 874 sf 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) N/A - -
16 Existing BUA that is already permitted(sq ft) - -
17 Existing BUA that will be removed(sq ft) - -
18 Percent BUA _ 41% _ 39% 56%
19 Design storm(inches) 1.0 in 1.0 in
20 Design volume of SCM(cu ft) 14674 cf 21489 cf
21 ,Calculation method for design volume SCS TR-20 SCS TR-20
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s): _
The drainage areas do not vary greatly from the previous design,however.
The 874 sf above indicates the amount of roadway/sidewalk that is
bypassed around the site.

SAND FILTER
1 Drainage area number 1 2 I
2 Minimum required treatment volume(Cu ft) 11967 sf 14459 sf
GENERAL MDC FROM 02H.1050
3 Is the SCM sized to treat the SW from all surfaces at build-out? Yen Ycn
4 Is the SCM located away from contaminated soils? Yes Yes
5 What are the side slopes of the SCM(H:V)? 3:1 3:1
6 Does the SCM have retaining walls,gabion walls or other engineered No Yes
side slopes?
7 Are the inlets,outlets,and receiving stream protected from erosion Yes Yes
(10-year storm)?
8 Is there an overflow or bypass for inflow volume in excess of the Yes Yes
design volume?
9 What is the method for dewatering the SCM for maintenance? Drawdown Orifice Drawdown Orifice
10 If applicable,will the SCM be cleaned out after construction? Yes Yes
11 Does the maintenance access comply with General MDC(8)? Yes Yes
12 Does the drainage easement comply with General MDC(9)? Yes Yes
If the SCM is on a single family lot,does(will?)the plat comply with
13 N/A N/A
General MDC(10)?
14 Is there an O&M Agreement that complies with General MDC(11)? Yes Yes
15 Is there an O&M Plan that complies with General MDC(12)? Yes Yes
16 Does the SCM follow the device specific MDC? Yes Yes
17 Was the SCM desi ned b an NC licensed rofessional? Yes Yes
SAND FILTER MDC FROM 02H.1056
18 SHWT elevation(fmsl) 658 653.5
19 Type of sand filter(open or closed) Open 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? No I No
Sediment Chamber
23 Volume that can be retained in the sediment chamber(cubic feet) ' 7467 cf 12380 cf
24 Will there be a permanent pool in the sediment chamber? No No
25 Bottom of the sediment chamber(fmsl) 668.00 657.00
26 Area of the sediment chamber(square feet) 1860 sf 4359 sf
27 Physical depth of the sediment chamber(inches) 36 in 30 in
28 Ponding depth in the sediment chamber,above any permanent pool 36 in 30 in
(inches)
29 Elevation of top of weir between chambers(fmsl) 671 659.5
Sand Chamber
30 Volume that can be retained in the sand chamber(cubic feet) 7207 cf 9109 cf
31 Bottom of the sand chamber(fmsl) 668.00 657.00
32 Area of the sand chamber(square feet) 1860 sf 3284 sf
33 Physical depth of the sand chamber(inches) 36 in 30 in
34 Ponding depth in the sand chamber,above the sand surface 36 in 30 in
(inches)
35 Elevation of the bypass device(fmsl) 671 659.5
36 Type of bypass device Outlet Control Outlet Control
Structure Structure
37 Mechanism for distributing flow over the sand surface "'„may"' Cap"'`.ay"
38 Sand specification for sand chamber _ ASTM C-33 ASTM C-33
39 Depth above underdrain pipe(inches) 12 in 12 in
40 Will the media be maintained to drain at least two inches per hour at Yes Yes
the sand surface?
41 Is at least one clean-out pipe provided at the low point of each Yes Yes
underdrain line?
42 Will clean-out pipes be capped? Yes Yes
ADDITIONAL INFORMATION
43 Please use this space to provide any additional information about the
sand filter(s):
2