SW6210907_Supplement-EZ Form_20211105

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
f PROJECT INFORMATION-
4f 1 Project Name
Timberland Gas Station
2 Project Area (ac) _
4.392
3 Coastal Wetland Area (ac)
4 ISurface Water Area ac
_ -
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 l Width of vegetated setbacks provided (feet) N/A
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 ? No
10 Is streambank stabilization proposed on this project? No
NUMBER AND TYPE OF SCMs:
11
Infiltration System
1
12
Bioretention Cell
0
13
Wet Pond
0
14
Stormwater Wetland
0
15
Permeable Pavement
0
16
Sand Filter
0
17
Rainwater Harvesting RWH
0
18
Green Roof
0
19
Level Spreader -Filter Strip LS-FS
0
20
Disconnected Impervious Surface DIS
0
21
Treatment Swale
0
22
Dry Pond
0
23
StormFilter
0
24
Silva Cell
0
25
Ba alter
0
26
_
Filterra
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and Title:
Organization—
Carlo Pardo, PE
28
Bowman North Carolina, Ltd.
29
_
Street address:
4004 Barrett Drive, Suite 101
30
City, State, Zip:
Raleigh, NC 27609
31
Phone numbers :
919-553-6570
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.
AIRQ�
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SEAL
051571
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Signature of Designer
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Date

DRAINAGE AREAS
1
Is this a high density project?
Yes
2
o, number of drainage areas/SCMs
If sDoes
1
3
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
Entfire Site
1
4
Type of SCM �~
-
Infiltration Basin
5
Total drainage area (sq ft
191320 sf
126116 sf
6
Onsite drainage area (sq ft
191320 sf
107849 sf
7
Offsite drainage area (sq ft
18267 sf
18267 sf
8
Total BUA in project (sq fl
101189 sf
92963 sf
9
New BUA on subdivided lots (subject to permitting)
(sq ft
10
New BUA not on subdivided lots (subject to
permitting) (sf)
11
Offsite BUA (sq ft
18267 sf
18267 sf
12
Breakdown of new BUA not on subdivided lots:
Parkin (sq ft
Sidewalk (sq ft
1718 sf
1718 sf
Roof (sq ft
3000 sf
3000 sf
Roadway s ft
70382 sf
62156 sf
Future (sq ft
Other, please specify in the comment box
below sq ft
7822 sf
7822 sf
13
New infiltrating permeable pavement on
subdivided lots (sq ft
14
New infiltrating permeable pavement not on
subdivided lots (sq ft
15permitting)_
Existing BUA that will remain (not subject to
s ft
16
Existing BUA that is already permitted (sq ft
17
xis inq BUA that will be removed (sq ft
18
Percent BUA
39.25%'On Site
74%
19
Design storm inches
1.0 in
20
Design volume of SCM (cu ft)
7498 cf
21 1
Calculation method for design volume
I Simple Method
ITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
Offsite Drainage area includes a portion of Calloway Road and the future Lot
68 in the Timberland Ranch development = 18267 sf. There is future
building/sidewalk/pavement included in the impervious calculations:
5000sf/620sf/2202sf, respectively = 7822 sf. There is 8226sf of bypass from

INFILTRATION SYSTEM
1 Drama e area number _ � 1
2 Minimum required treatment volume (cu ft) 7498 cf
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 or enter "Vertical' for
trenches)?
3:1
6
Does the SCM have retaining walls, gabion walls or other engineered
side slopes?
No
7
Are the inlets, outlets, and receiving stream protected from erosion
(10- ear 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
13
If the SCM is on a single family lot, does (will?) the plat comply with
General MDC (10)?
NIA
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 rofessional?
Yes
TIM cvc-mM iM FROM fixk{ . Si
18
Proposed sloe of the subgrade surface (°l,)
0%
19
Are terraces or bafflesprovided?
No
20
]Type of pretreatment:
Forebay
21
Was the soil investigated in the footprint and at the elevation of the
infiltrations stem?
Yes
22
SHWT elevation (fmsl)
366.00 _
23
Depth to SHWT per soils report (in)
180.00
24
Ground elevation at boring in soils re ort (fmsl)
381.00
25
Is a detailed hydrogeologic study attached if the separation is
between 1 and 2 feet?
Yes
26
Soil infiltration rate (in/hr)
11.00
27
Factor of safety (FS) (2 is recommended):
2.00
Elevaflbns
29
Bottom elevation (fmsl)
378 ft
30
Storage elevation (fmsl)
380. ft
31
Bypass elevation (fmsl)
380.7 ft
For Basins Only
32
Bottom surface area (ft 2)4975 ft
33
Stora a elevation surface area ft2 7075. ft
34
Length (ft)
35
jWidth (ft)
36
jPerforated pipe diameter, if applicable (inches)
37
Number of laterals
38
Total len th of perforated piping
39
Stone type, if applicable
40
Stone porosity (%)
41
Is stone free of fines?
42
Is the stone wrapped in 2eotextile fabric?
43
Has at least one inspection port been provided?
Volumes/Drawdown
44 IDesion volume of SCM (cu ft) 7498 of
45 ITime to draw down (hours) 3 hrs
ADDITIONAL INFORMATION
46 Please use this space to provide any additional information about the
infiltration system(s):
Infiltration 3 9:50 AM 1012212021