SW6130203_Supplement-EZ Form_20240423

SUPPLEMENT-EZ COVER PAGE
PROJECT INFORMATION
1 Pro'ect Name O'Reilly Auto Parts Area Infiltration Basin
2 Pro'ect Area(ac) 8.977548
3 Coastal Wetland Area(ac)
4 Surface 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 Width of vegetated setbacks provided(feet) _ _ 30
8 Will the vegetated setback remain vegetated? Yes j
9 If BUA is proposed in the setback,does it meet NCAC 02H.1003(4)(c-d)? N/A r
10 Is streambank stabilization proposed on this project? No
NUMBER AND TYPE OF SCMs: I
11 Infiltration System 1 _
12 -Bioretention Cell
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 Bayfilter _
26 Filterra
FORMS LOADED
DESIGNER CERTIFICATION
27 Name and Title: Jarrod E.Hilliard,PE,CFM
28 Or!anization: Hilliard Engineering, PLLC
•Street address: 3417 Winterwind Circle
30 Cit ,State,Zip: Sanford, NC 27330
31 Phone number(s): 919-352-2834
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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• Si ature of Designer 99"" //
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Seal Date

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
Is all/part of this project subject to previous rule
5 [versions? No
FORMS LOADED
DRAINAGE AREA INFORMATION Entire Site 1 ,. 1
4 Type of SCM Infiltration Basin Infiltration Basin 4F
5 Total drainage area(sq ft) 391,062 374616
6 Onsite drainage area(sq ft) 391,062 374616
7 Offsite drainage area(sq ft)
8 Total BUA in project(sq ft) 318424 sf 318424 sf
New BUA on subdivided lots(subject to permitting)
9 , s' ft) 297634 sf 297634 sf
New BUA not on subdivided lots(subject to
10 permittn.)(sf) 20800 sf 20800 sf _
En Offsite BUA(sq ft)
lal Breakdown of new BUA not on subdivided lots: _
-Parking(sq ft)
agi -Sidewalk(sq ft)
1111111 -Roof(sq ft)
_ -Roadway(sq ft) 20800 sf 20800 sf
_ -Future(sq ft)
-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
1 15 `permitting)(sq ft)
16 Existing BUA that is already permitted(sq ft)
17 Existing BUA that will be removed(sq ft)
18 Percent BUA 81% 85%
19 Design storm(inches) 1.0 in
20 Design volume of SCM(cu ft) 25444 cf
21 Calculation method for design volume simple
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 ;drainage area(s):

INFILTRATION SYSTEM
Drainage area number 1
2 1 Minimum reauired treatment volume (cu ft) 2b444 c
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
desi n volume?
Yes
9
lWhat 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
1 Does the SCM follow the device specific MDC?
Yes
17
lWasthe SCM designed b an NC licensedprofessional?
Yes
INFILTRATION
SYSTEM MDC FROM 02H .10S1
18
Proposed slope of the subgrade surface (%)
000
19
jAre terraces or baffles provided?
No
20
IType of pretreatment:
Forebay
I Soils Data
21
Was the soil investigated in the footprint and at the elevation of the
infiltration system?
Yes
22
SHWT elevation fmsl
< 414
23
Depth to SHWT per soils report (in)
> 124
24
Ground elevation at boring in soils report fmsl
424.30
25
1 Is a detailed hydrogeologic study attached if the separation is
between 1 and 2 feet?
N/A
26
ISoil infiltration rate (in/hr)
0.91
27
1 Factor of safety (IFS) 2 is recommended):
2.00
(Elevations
evation fmsl
420.00
levation (fmsl)
=IBypass
422. ft
levation fmsl
422 ft
For Basins Only
32 Bottom surface area(ft) 11373 ft
33 Storage elevation surface area(ft) 14102. ft
Fnr Tranchac I1niv
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 applicable
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?
Volumes/Drawdown
44 IDesign volume of SCM cu ft25444 cf
45 ITime to draw down (hours) 59 hrs
I 46 Please use this space to provide any additional information about the
infiltration system(s):
Infiltration 1 9:23 AM 7/26/2024