SWA000216_Supplement-EZ Form_20230801

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED I
PROJECT INFORMATION
1 Project Name _ L CIRCLE K-EXPANSION 2723205 -WINSTON SALEM,NC
2 Project Area(ac) _ 1.72
3 Coastal Wetland Area(ac) _ N/A
4 Surface Water Area(ac) _ N/A _
5 Is this project High or Low Density? High _
6 Does this project use an off-site SCM? I No
COMPLIANCE WITH 02H.1003(4)
7 Width of vegetated setbacks provided(feet) 0
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 I Is streambank stabilization proposed on this project? No
NUMBER AND TYPE OF SCMs:
11 Infiltration System
12 Bioretention Cell 1
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 Bayfilter26 Filterra
FORMS LOADED
DESIGNER CERTIFICATION
27 Name and Title: _ Jacob Dooley
28 Organization: _ Timmons Group
29 Street address: 5410 Trinity Rd Suite 102
30 City,State,Zip: Raleigh,NC 27607
31 Phone number(s): 919-866-4937
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 4
3 Does this project have low density areas? _ No
4 If so.number of low density drainage areas 0
5 'Is all/part of this project subject to previous rule
versions? No
FORMS LOADED
DRAINAGE AREA INFORMATION Entire Site 1 2 3 4
4 Type of SCM Bioretention Cell N/A(Bypass) _
5 Total drainage area(sq ft) 34202 22300 _ 11902
6 Onsite drainage area(sq ft) _ 30503 19291 11212
7 Offsite drainage area(sq ft) 3699 3016 _ 683
8 Total BUA in project(sq ft) 12004 sf _ 11878 sf 126 sf _
New BUA on subdivided lots(subject to permitting)
9 (sq ft) — — —New BUA not on subdivided lots(subject to
10 permitting)(sf) 11889 sf 11878 sf 11 sf
11 Offsite BUA(sq ft) _ 2835 Sf 2554 sf 281 sf _
12 Breakdown of new BUA not on subdivided lots:
-Parking(sq ft) 13179 sf 10625 sf _ 2554 Sf-Sidewalk(sq ft) 412 sf 412 sf
-Roof(sgft) 816sf 816sf
-Roadway(sq ft)
-Future(sq ft) 1307 sf 1307 sf _
-Other,please specify in the comment box
below(sq ft) -
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) -- __ 1403 sf
17 Existing BUA that will be removed(sq ft) 1403 sf
18 Percent BUA 62%
19 Design storm(inches) 1.0 in
20 Design volume of SCM(cu ft) 1502 cf
21 !Calculation method for design volume Simple Method
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):

BIORETENTION CELL
1 Drainage area number 1
2 Minimum required treatment volume(cu ft) 1232 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
6 Does the SCM have retaining walls,gabion walls or other
engineered side slopes? No
Are the inlets,outlets,and receiving stream protected from erosion 7
(10-year storm)? Yes _
8 Is there an overflow or bypass for inflow volume in excess of the
design volume? Yes
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)? N/A
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 designed by an NC licensed professional? Yes
BIORETENTION CELL MDC FROM 02H.1052
18 SHWT elevation(fmsl) <870.5'
19 Bottom of the bioretention cell(fmsl) 880.83
20 Ponding depth of the design storm(inches) 12 in
21 Surface area of the bioretention cell(square feet) 1724 sf
22 Design volume of SCM(cu ft) 1502 cf
23 Is the bioretention cell used for peak attenuation? Yes
24 Depth of peak attenuation over planting surface(in) 24 in _
25 Height of peak attenuation outlet above the planting surface(in) 18 in
26 Infiltration rate of the in situ soil(inch/hour) TBD
27 Diameter of the underdrain pipes(if applicable) 4 in
28 Does the design include Internal Water Storage(IWS)? Yes
29 if so,elevation of the top of the IWS(fmsl) 883.5 _
30 Elevation of the planting surface(fmsl) 885 _
31 What type of vegetation will be planted? (grass,trees/shrubs,
other)? Grass
32 Media depth(inches) 30 in _
33 Percentage of medium to coarse washed sand by volume 75-85%
34 Percentage of fines(silt and clay)by volume 8-10%
35 Percentage of organic matter by volume 5-10%
36 Type of organic material Pine bark fines_
37 Phosphorus Index(P-Index)of media(unitless) <50
38 Will compaction be avoided during construction? Yes _
39 Will cell be maintained to a one inch/hour standard? Yes _
40 Depth of mulch,if applicable(inches) N/A _
41 Type of mulch,if applicable N/A
42 How many clean out pipes are being installed? 2
Grass/Gravel
43 Type of pretreatment that will be used: Combination
ADDITIONAL INFORMATION
44 Please use this space to provide any additional information about
the bioretention cell(s):
Bioretention 1 1:44 PM 6/5/2023