20181245 Ver 2_Supplement 9_11_20_20200911

SUPPLEMENT-EZ COVER PAGE
FORMS LOADED
PROJECT INFORMATION
1
Project Name
Ferguson Street Development
2
Project Area ae
22.31 Armes
3
Coastal Wetland Area ac
0
4
Surface Water Area ac
3.33
5
Is this ro ect High or Low Dens"
Both High and Low DengtY
6
Does this project use an off -site SGM?
No
CQMMIAHCIEAIFI4►ZH 00,NQ.
7
Width of vegetated! setbacks provided feet
30
$
W II the vegetated setback remainvegetated?
Yes
9
If 13UA is Proposed in the setback does R meet NCAC 02H.1003 4 c-d ?
NIA
10
1 Is stmambank stabilization pWosed an this project?
No
NUMBER AND TYPE OF SCMs:
11 Infiltration� tem
12 1 Bioretention Cell _
13 jWet Pond
14 1 Starmwater Wetland ^ -
1
15
Permeable Pavement
16
Sand Filter
17
Rainwater Harvesting RWH
18
Green Roof
19
Level S reader -Fitter Strip LS-FS
20
Disconnected Im erviaus Surface (DIS)T
Treatment Swale
22
D Pond
1Ba21
231
3
StormFifter
24
Silva Cell
25
Iter
26
l iltelra
FORMS LOADED
OESIGHER GERT1FICATIQN
'
Name and Title.
William A- Stftell, Proje� Engineer
Organization.
Stlllwell E�nBering Inc.
L3D
Street address-
42 Marsh LilyDrive
Ci State. 7s-
S lva, NC 28779
Phone number: _ _.
828.58&6066
32
Email:
w-stillwetl@sh'llwellengineertng.net
Certification Statement
I oertify, 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 hest of my knowledge and bel ef, "e, accurate, and complete; and that the engineering plans,
specifications, operation and maintenance agreements and other supparting information are consistent with the information provided here.
Designer
Signature of Designer
?/ I/I ko
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?Yes
4 If so, number of low density drainage areas 1
5
Is all/part of this project subject to previous rule
versions?No
FORMS LOADED
Entire Site 1 LD 1
4 Type of SCM Bioretention Cell None
5 Total drainage area (sq ft)241323 140699 100624
6 Onsite drainage area (sq ft)241323 140699 100624
7 Offsite drainage area (sq ft)0 0 0
8 Total BUA in project (sq ft)124307 sf 102366 sf 21941 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)
12 Breakdown of new BUA not on subdivided lots:
- Parking (sq ft)62928 sf 2592 sf
- Sidewalk (sq ft)5638 sf sf
- Roof (sq ft)18800 sf 7776 sf
- Roadway (sq ft) sf 11573 sf
- Future (sq ft) sf sf

- Other, please specify in the comment box
below (sq ft) 15000 sf sf
13
New infiltrating permeable pavement on subdivided
lots (sq ft) sf sf
14
New infiltrating permeable pavement not on
subdivided lots (sq ft) sf sf
15
Existing BUA that will remain (not subject to
permitting) (sq ft) sf sf
16 Existing BUA that is already permitted (sq ft) sf sf
17 Existing BUA that will be removed (sq ft)21245 sf sf
18 Percent BUA 73%22%
19 Design storm (inches)1.0 in
20 Design volume of SCM (cu ft)6703 cf
21 Calculation method for design volume Simple Method
22
DRAINAGE AREA INFORMATION
ADDITIONAL INFORMATION
15, 000 SF of concrete slab display area
Please use this space to provide any additional information about the
drainage area(s):
1 Drainage area number 1
2 Minimum required treatment volume (cu ft)6703 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)?: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?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 device specific MDC?Yes
17 Was the SCM designed by an NC licensed professional?Yes
18 SHWT elevation (fmsl)2141.87
19 Bottom of the bioretention cell (fmsl)2144.33
20 Ponding depth of the design storm (inches)12 in
21 Surface area of the bioretention cell (square feet)7459 sf
22 Design volume of SCM (cu ft)6683 cf
23 Is the bioretention cell used for peak attenuation?No
24 Depth of peak attenuation over planting surface (in) in
25 Height of peak attenuation outlet above the planting surface (in) in
26 Infiltration rate of the in situ soil (inch/hour)0.45 In/Hr
27 Diameter of the underdrain pipes (if applicable)4 in
28 Does the design include Internal Water Storage (IWS)?Yes
29 if so, elevation of the top of the IWS (fmsl)2146
30 Elevation of the planting surface (fmsl)2147.5
31 What type of vegetation will be planted? (grass, trees/shrubs,
other)?Grass
32 Media depth (inches)30 in
33 Percentage of medium to coarse washed sand by volume 75%
34 Percentage of fines (silt and clay) by volume 8%
35 Percentage of organic matter by volume 5%
36 Type of organic material Pine Bark Fines
37 Phosphorus Index (P-Index) of media (unitless) 49 Max
38 Will compaction be avoided during construction?Yes
39 Will cell be maintained to a one inch/hour standard?Yes
40 Depth of mulch, if applicable (inches)N/A
41 Type of mulch, if applicable N/A
42 How many clean out pipes are being installed?8
43 Type of pretreatment that will be used:Forebay
44 Please use this space to provide any additional information about the
bioretention cell(s):
BIORETENTION CELL MDC FROM 02H .1052
GENERAL MDC FROM 02H .1050
ADDITIONAL INFORMATION
BIORETENTION CELL
Bioretention 1 3:06 PM 9/11/2020
LOW DENSITY      
1 Yes
2 Yes
3 Yes
4 N/A
5
6 No
7 n/a
8 n/a
9 n/a
10 n/a
11 No
12 N/A
13 Yes
14 No
15
Swale
#
Drainage
Area
(ac)
BUA
(ac)
Pervious
area
(ac)
C Q
(cfs)
Slope
(%)
Vallow
(fps)
Vactual
(fps)
Flow depth
(ft)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Does project maximize dispersed flow and minimize channelization of flow?
Is project below density thresholds set forth in the applicable stormwater rule?
DESIGN REQUIREMENTS FOR LOW DENSITY PROJECTS FROM 02H .1003
ADDITIONAL INFORMATION
Has the use of piping been minimized per .1003(2)(c)?
Are treatment swales used instead of curb outlet swales?
Minimum length of curb outlet swale(s) (feet)
Maximum side slope of curb outlet swale(s) (H:V)
Bottom width of curb outlet swale(s) (feet)
Maximum longitudinal slope of curb outlet swale(s) (%)
Are curb outlet swales proposed?
Maximum velocity in the vegetated conveyances during the 10-year storm?
Side slopes of the vegetated conveyances (H:V)
Project development intends to use sheet flow dispersment of storm water.
Are variations to rule .1003 proposed?
Have stormwater outlets been designed to prevent downslope erosion?
Is stormwater released at the edge of the setback as dispersed flow?
Please use this space to provide any additional information about this low density project: