SW3240703_Supplement-EZ Form_20240801

SUPPLEMENT-EZ COVER PAGE
PROJECT INFORMATION
1 Project Name PPI Office and Welding
2 Project Area(ac) 4.192
3 Coastal Wetland Area(ac) N/A
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) N/A
8 Will the vegetated setback remain vegetated? N/A
If BUA is proposed in the setback,does it meet
9 NCAC 02H.1003(4)(c-d)? N/A
Is streambank stabilization proposed on this
10 project? No
NUMB E OF SCMs: —
11 Infiltration System 0
12 Bioretention Cell 0
13 Wet Pond 0
14 Stormwater Wetland 0
15 Permeable Pavement 0
16 Sand Filter 1
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 Filterra 0
DESIGNER CERTIFICATION W
27 Name and Title: Kate Underwood,PhD,PE
28 Organization: Daylight Engineering
29 Street address: PO Box 1804
30 City,State,Zip: Concord,NC 28026-1804
31 Phone number(s): 980-234-7500
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 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
DRAINAGE AREA INFORMATION n ire 1 e an 1 er
4 Type of SCM n/a Sand Filter
5 Total drainage area (sq ft) 156,119 136,622
6 Onsite drainage area (sq ft) 156,119 136,622
7 Offsite drainage area (sq ft) 0 0
8 Total BUA in project(sq ft) 108,777 103,892
9 New BUA on subdivided lots (subject to permitting) (sq ft) 0 0
10 New BUA not on subdivided lots(subject to permitting)(sf) 108,777 103,892
11 Offsite BUA(sq ft) n/a n/a
12 Breakdown of new BUA not on subdivided lots: 108,777 103,892
- Parking (sq ft) 10,423 5,538
-Sidewalk(sq ft) 6,741 6,741
- Roof(sq ft) 12,414 12,414
- Roadway(sq ft) 0 0
- Future (sq ft) 0 0
-Other, please specify in the comment box below(sq ft) 79,199 79,199
New infiltrating permeable pavement on subdivided lots(sq
13 ft) n/a n/a
New infiltrating permeable pavement not on subdivided lots
14 (sq ft) n/a n/a
Existing BUA that will remain (not subject to permitting) (sq
15 ft) n/a n/a
16 Existing BUA that is already permitted (sq ft) n/a n/a
17 Existing BUA that will be removed (sq ft) n/a n/a
18 Percent BUA 69.7% 76.0%
19 Design storm (inches) 1.0 in 1.0 in
20 Design volume of SCM (cu ft) n/a 5,662
Discrete NRCS
n/a Curve Number
Method for
21 Calculation method for design volume Runoff Depth
ADDITIONAL INFORMATION
22 Please use this space to provide any additional information about the drainage
The "Other" impervious area consists of the gravel lot, and concrete slab around the building
bay door entrances and dumpster enclosure. There is also approximatley 4,885 sq. ft of
impervious area that is not being captured and rotued into the propsoed SCM. That is why the
"Parking" impervious area is different in the two columns.

SAND FILTER
1 Drainage area number 1
2 Minimum required treatment volume(cu ft) 2085
'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
7 Are the inlets,outlets,and receiving stream protected from erosion(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? Drawdown Orifice
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 device specific MDC? Yes
17 Was the SCM designed by an NC licensed professional? Yes
SAND FILTER MDC FROM 02H.1056
18 SHWT elevation(fmsl) 683
19 Type of sand filter(open or closed) Open
20 If closed,will the filter will be pre-cast or pour-in-place? n/a
21 If closed,top of grate elevation(fmsl) n/a
22 Is this sand filter designed to attenuate peak flows? Yes
Sediment Chamber
23 Volume that can be retained in the sediment chamber(cubic feet) 2705 cf
24 Will there be a permanent pool in the sediment chamber? No
25 Bottom of the sediment chamber(fmsl) 689.00
26 Area of the sediment chamber(square feet) 1812 sf
27 Physical depth of the sediment chamber(inches) 24 in
28 Ponding depth in the sediment chamber,above any permanent pool(inches) 24 in
29 Elevation of top of weir between chambers(fmsl) 691
(Sand Chamber
30 Volume that can be retained in the sand chamber(cubic feet) 2956 cf
31 Bottom of the sand chamber(fmsl) 689.00
32 Area of the sand chamber(square feet) 1947 sf
33 Physical depth of the sand chamber(inches) 24 in
34 Ponding depth in the sand chamber,above the sand surface(inches) 24 in
35 Elevation of the bypass device(fmsl) 691
36 Type of bypass device Riser Weir
37 Mechanism for distributing flow over the sand surface Riprap Weir
38 Sand specification for sand chamber ATSM C33 or equivalent
39 Depth above underdrain pipe(inches) 24 in
40 Will the media be maintained to drain at least two inches per hour at the sand surface? Yes
41 Is at least one clean-out pipe provided at the low point of each underdrain line? Yes
42 Will clean-out pipes be capped? Yes
ADDITIONAL INFORMATION
43 Please use this space to provide any additional information about the sand filter(s):