SW6220301_Signed Long Point EZ Supplement_20221116

SUPPLEMENT-EZ COVER PAGE
faRMS LOADED
PROJECT INFORMATION
1
Project Name
Lang Point Subdivision
2
Projecl Area (ac)
34.14
3
Coastal Wetland Area (ac)'
4
Surface Water Area (ac)'
5
Is this project High or Low Density?
Hi h
6
1 Does this project use an off -site SCM?
No
COMPLIANCE WITH 62H .1003(4
7
Width of vegetated setbacks provided feet
30
8
Will the vegetated setback remain vegetated?
Yes
9
If BUA is proposed in the setback, does it meet NCAC 02H.1003(4Cil ?
N!A
10
Is streambank stabilization proposed on this projedt?
No
NUMBER AND TYPE OF SCMs:
Infiltration System
1
12
Bioretention Cell
0
F1511
13
Wet Pond
2
14
Stormwater Wetland
0
Permeable Pavement
Sand Filter
0
16
0
17
Rainwater Harvesting RWH)
0
18
Green Roof
0
19
_
Level Spreader -Filter Strip (1S-FS
0
20
Disconnected Impervious Surface (DIS)
0
21
Treatment Swale
0
22
Dry Pond
D
23
StormFilter
0
24
Silva Cell
0 _
25
Bayfilter
0
26
Filterra
0
FORMS LOADED
DESIGNER CERTIFICATION
27
Name and Title:
Of anization
Street address:
Carlo Pardo, PE
28
Bowman North Carolina, Ltd_
29
4006 Barrett Drive, Suite 104
30
City, State, Zip:
Ralei h, NC 27609
31
Phone number(s):
Email:
919-5'%6570
32
[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 forth 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.
C A 1R rr/tt'o
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Signature of esigner '
Date I

DRAINAGE AREAS
1
Is this a hi h densit ro'ect?
Yes
2
If so, number of draina a areas/SCMs
3
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 LOADFD
DRAINAGE AREA INFORMATION
Entire Site
1
2
3
4
Type of SCM
Wet Pond
Wet Pond
Infiltration Basin
5
Total drainage area (sq ft
1487139 sf
384558
113843
424106
6
Onsite drainage area (sq ft
1487139 sf
384558
113843
424106
7
Offsite drainage area (sq ft
8
Total BUA in project (sq ft
336735 sf
139536 sf
47257 sf
147943 sf
9
New BUA on subdivided lots (subject to permitting)
(sq ft
242000 sf
104000 sf
26000 sf
112000 sf
10
New BUA not on subdivided lots (subject to
ermittin s
94735 sf
35536 sf
21257 sf
35943 sf
11
Offsite BUA (sq ft
12
Breakdown of new BUA not on subdivided lots:
Parking (sq ft
Sidewalk �sq ft
1766 sf
1766 sf
- Roofs ft
Roadway s ft
85615 sf
35536 sf
12137 sf
35943 sf
Future (sq ft
Other, please specify in the comment box
below (sq ft
7354 sf
7354 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
Existing BUA that will be removed (sq ft
9318 sf
9318 sf
18
Percent BUA
22.64%
36.3%
42%
35%
19
Desi n storm inches
1.0 in
1.0 in
1.0 in
20
Design volume of SCM cu ft
12068 cf
4029 cf
12863 cf
21 .
Calculation method for design volume
Simple Method
Simple Method
Simple Method
ADDITIONAL INFORMATION
Please use this space to provide any additional information about the
22 drainage area(s):
Entire Site: Existing 9,318 sf Impervious Area to be removed from DA2
Other: Pool & Building from DA2
There is 1,999 sf of impervious roadway area that will bypass Wet Pond 2

WET POND
1
Drainage area number 1 1 2
2
Minimum reg ulred tfeatment volume cu ft 12068 cf L 4029 cf
GENERAL
MDC FROM 02H .3050
3
Is the SCM sized to treat the SW from all surfaces at build -out?
Yes
Yes
4
Is the SCM located awayfrom contaminated soils?
Yes
Yes
5
What are the side slopes of the SCM H: ?
3:1
3:1
6
F7
Does the SCM have retaining walls, gabion walls or other
en ineered side slo-es?
No
No
Are the inlets, outlets, and receiving stream protected from erosion
10- ear storm)?
Yes
Yes
8
Is there an overflow or bypass for inflow volume in excess of the
desi n volume?
Yes
Yes
9
What is the method for dewatering the SCM for maintenance?
Pump (preferred)
Pump referred
10
If applicable will the SCM be cleaned out after construction?
Yes
Yes
111
Does the maintenance access comply with General MDC (8)?
Yes
Yes
12
Does the drainage easement comply with General MDC (9)?
Yes
Yes
13
If the SCM is on a single family lot, does (will?) the plat comply with
General MDC 10 ?
N/A
N/A
14
Is there an O&M Agreement that complies with General MDC (11)?
Yes
Yes
15
Is there an O&M Plan that complies with General MDC 12 ?
Yes
Yes
16
Does the SCM follow the devicespecific MDC?
Yes
Yes
17
Was the SCM designed by an NC licensedprofessional?
Yes
Yes
WET POND
MDC FROM 02H .1053 _
18
Sizing method used
SA/DA
SA/DA
19
Has a stage/storage table been provided in the calculations?
Yes
Yes
20
Elevation of the excavated main pool depth (bottom of sediment
removal) (fmsl
250.00
247.00
21
Elevation of the main pool bottom (top of sediment removal) (fmsl)
251.00
248.00
22
1 Elevation of the bottom of the vegetated shelf fmsl
258.50
252.50
231
Elevation of the permanent pool (fmsl)
259.00
253.00
24
Elevation of the top of the vegetated shelf fmsl
259.50
253.50
25
Elevation of the temporary pool fmsl
259.80
253.80
26
Surface area of the main permanent pool (square feet)
11690
2850
27
Volume of the main permanent pool (cubic feet)
42894 cf
6423 cf
28
Avera a depth of the main pool feet
4.47 ft
3.02 ft
29
Avera a depth euation used
Equation 3
Equation 3
301
If using equation 3, main pool perimeter (feet
747.0 ft
274.0 ft
311
If using equation 3, width of submerged veg. shelf (feet)
3.0 ft
3.0 ft
32
Volume of the foreba cubic feet
8120 cf
1024 cf
33
Is this 15-20% of the volume in the mainpool?
Yes
Yes
34
Clean -out depth for foreba (inches)
18 in
18 in
35
Design volume of SCM (cu ft)
12068 cf
4029 cf
36
Is the outlet an orifice or a weir?
Orifice
Orifice
37
If orifice, orifice diameter inches
1.75 in
1.00 in
381
If weir, weir height inches
391
If weir, weir length (inches)
40
Drawdown time for the tempospool (days)
2.52
2.40
41
Are the inlet(s) and outlet located in a manner that avoids short-
circuiting?
Yes
Yes
42
Are berms or baffles provided to improve the flowpath?
Yes
Yes
43
Depth of forebay at entrance inches
30 in
30 in
44
Depth of forebay at exit inches
24 in
24 in
45J
Does water flow out of the forebay in a non -erosive manner?
Yes
Yes
46
Width of the vegetated shelf feet
6 ft
6 ft
47
Slope of vegetated shelf (H:
6:1
6:1
48
Does the orifice drawdown from below the top surface of the
permanentpool?
Yes
Yes
49
Does the pond minimize impacts to the receiving channel from the 1
r 24-hr storm?
Yes
Yes
50
Are fountains proposed? (If Y, please provide documentation that
MDC(9) is met.
No
No
51
Is a trash rack or other device provided to protect the outlet system?
Yes
Yes
52
Are the dam and embankment planted in non -clumping turf grass?
Yes
Yes
53
Species of turf that will be used on the dam and embankment
Hybrid Bermuda
H brid Bermuda
54
Hasa elanting Elan been provided for the ve etated shelf?
Yes
Yes
ADDITIONAL INFORMATION
55
Please use this space to provide any additional information about
the wet pond(s):
Entire Site: Existing 9,318 sf Impervious Area to be removed from DA2
There is 1,999 sf of impervious roadway area that will bypass Wet Pond 2
Wet Pond 1 9:18 AM 11/14/2022

INFILTRATION SYSTEM
�1 Drainage area number 3
2 1 Minimum reauired treatment volume (cu ft) 12863 cf
3
Is the SCM sized to treat the SW from all surfaces at build -out?
j 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 licensed professional?
Yes
18 jProposed.slope of the subgrade surface (%) 0%
19 Are terraces or baffles provided? No
20 Type of pretreatment: Forebay
Cnuc nntn
21
Was the soil investigated in the footprint and at the elevation of the
infiltrations stem?
Yes
22
SHWT elevation fmsl
241.00
23
Depth to SHWT per soils report in
87.60
24
Ground elevation at boring in soils report (fmsl)
248.30
25
Is a detailed hydrogeologic study attached if the separation is
between 1 and 2 feet?
N/A
26
Soil infiltration rate (in/hr)
6.00
27
Factor of safety (FS) (2 is recommended):
2.00
E/evatxons
29
Bottom elevation (fmsl) 246 ft
30
1 Storage elevation fmsl 247.1 ft
31
lBypass elevation fmsl) 250.3 ft
For Basins Only
32
Bottom surface area ftz
11195 ft
33
1.8torage elevation surface area
12880. ft
Fnr Tranrhaa
r)n/v
34
Length (ft)
35
Width (ft)
36
Perforated pipe diameter, if applicable inches
37
Number of laterals
38
Total len th of perforated pipin .
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?
Vo/ume&Drawdown
44 IDesign volume of SCM cu ft12863 cf
45 1 Time to draw down hours 4.6 hrs
ADDITIONAL INFORMATION T
46 Please use this space to provide any additional information about the
infiltration system(s):
26-The infiltration rate was intentially lowered to 75% of the 8 in/hr to account for
]inq of the soils that will happen over time.
Infiltration 1 11:15 AM 11/14/2022