SW6211203_Supplement-EZ Form_20220310

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1
Project Name
McCain Gas Station
2
Project Area (ac)
5.096
3
Coastal Wetland Area ac
4
Surface Water Area (ac)-
5
1 Is this project High or Low Density?
High
6
Does this project use an off -site SCM?
No
COMPLIANCE WITH 02H .1003(4)
7
1 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
1 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
Bayfilter
0
26 lFilterra
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and Title.
Carlo Pardo. PE
28
Organization:
Bowman North Carolina, Ltd.
29
Street address:
4006 Barrett Drive, Suite 104
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.
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Signature of Designer
30-6/9-2Date

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
5
Is all/part of this project subject to previous rule
versions?
No
FORMS LOADED
DRAINAGE AREA INFORMATION
Entire Site
1
4
Type of SCM
-
Infiltration Basin
5
Total drainage area (sq ft
221969 sf
149468
6
Onsite drainage area (sq ft
134646
7
Offsite drainage area (sq ft
14822
8
Total BUA in project (sq ft
65624 sf
91439 sf
9
New BUA on subdivided lots (subject to permitting)
(sq ft
10permitting)
New BUA not on subdivided lots (subject to
s
11
Offsite BUA (sq ft
14822 sf
12
Breakdown of new BUA not on subdivided lots
Parkin2 (sq ft
56714 sf
56714 sf
Sidewalk (sq ft
1910 sf
1910 sf
Roof (sq ft
7000 sf
7000 sf
Roadway s ft
Future (sq ft)
10993 sf
Other, please specify in the comment box
below (sq ft
13
New infiltrating permeable pavement on
subdivided lots (sq ft
14
New infiltrating permeable pavement not on
subdivided lots (sq ft
15[permitting)
Existing BUA that will remain (not subject to
(sq ft)
13158 sf
16
Existing BUA that is already ermitted sq ft
17
Existing BUA that will be removed (sq ft
2091 sf
2091 sf
18
Percent BUA
29.56%
61.2%
19
Design storm inches
1.0 in
20
Design volume of SCM cu ft
7481 cf
21
Calculation method for design volume
Simple Method
ADDITIONAL INFORMATION
22
Please use this space to provide any additional information about the
draina a area(s):
Entire Site: Existing 19,988 sf Impervious Area
Future: Existing Impervious area that will be future NCDOT roadway

INFILTRATION SYSTEM
1 Drainage area number 1
2 1 Minimum required treatment volume (cu ft) 7481 ct
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)?
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 devicespecific MDC?
Yes
17
Was the SCM designed by an NC licensedprofessional?
Yes
INFILTRATION
SYSTFM mne FROM nilu .1nSS
18
Proposed slope of the subgrade surface (%)
0%
19
Are terraces or bafflesprovided?
No
20
Type of pretreatment:
Forebay
I Soils Data
21
Was the soil investigated in the footprint and at the elevation of the
infiltrations stem?
Yes
22
SHWT elevation fmsl
<422.0
23
Depth to SHWT per soils report (in)
> 15ft
24
Ground elevation at boring in soils report (fmsl)
437.00
25
Is a detailed hydrogeologic study attached if the separation is
between 1 and 2 feet?
N/A
26
Soil infiltration rate in/hr
9.00
27
Factor of safety (FS) (2 is recommended):
2.00
Elevations
29
Bottom elevation fmsl
436 ft
30
Storage elevation (fmsl)
437.3 ft
31
Bypass elevation (fmsl)
439.4 ft
For Basins Only
1 Bottom surface area ftZ
5385 ft
I32
33
IStorage elevation surface area (ftz)
6560. ft
Fnr Trenches
Oniv
34
Length (ft)
35
Width (ft)
36
Perforated pipe diameter, if applicable (inches)
37
Number of laterals
38
Total length of perforated piping
39
Stone type, if aeplicable
40
Stone Porosity(%)
41
Is stone free of fines?
42
Is the stone wrapped in geotextile fabric?
43
Has at least one inspection port been provided?
voiumesmrawdown
44 Desi n volume of SCM cu ft) 7481 cf
45 Time to draw down (hours) 3.7 hrs
ADDITIONAL INFORMATION
46 Please use this space to provide any additional information about the
infiltration system(s):
26-The infiltration rate was intentially lowered to half of the 18 in/hr to account for
ling of the soils that will happen over time.
Infiltration 1 11:11 AM 3/10/2022