SW5120203_Supplement_20120321

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NCDENR
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MAY 2 4 2012
NC DENR
Raleigh Regional Office
STORMWATER MANAGEMENT PER iT RPPEICATION-FORM
401 CERTIFICATION APPLICATION FORM
WETLAND SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 111) must be printed, filled out and submitted along with all the required information.
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I. PROJECT INFORMATION
Project name
State Employees' Credit Union - Siler City
Contact name
Jon Aldridge
Phone number
919-361-5000
Date
March 21, 2011
Drainage area number
1A - To SWMF
II. DESIGN INFORMATION
Site Characteristics
Drainage area
97,346.00 ftz
Impervious area
68,009.00 ft2
Percent impervious
69.9% %
Design rainfall depth
1.00 inch
Peak Flow Calculations
1-yr, 24-hr rainfall depth
1-yr, 24-hr intensity
Pre -development 1-yr, 24-hr runoff
Post -development 1-yr, 24-hr runoff
Pre/Post 1-yr, 24-hr peak control
Storage Volume: Non -SA Waters
Minimum required volume
Volume provided (temporary pool volume)
Storage Volume: SA Waters Parameters
1.5" runoff volume
Pre -development 1-yr, 24-hr runoff volume
Post -development 1-yr, 24-hr runoff volume
Minimum volume required
Volume provided .
Outlet Design
Depth of temporary poollponding depth (DP1an15)
Drawdown time
Diameter of orifice
Coefficient of discharge (Co) used in orifice diameter
calculation
Driving head (Ho) used in the orifice diameter calculation
2.99
in
0.12
inlhr
0.37
ft3lsec
0.32
ft3lsec
-0.05
ft3lsec
5,505.00 ft3
5,563.00 ft3 OK
ft3
ft3
It
ft3
12.00 in OK
2.35 days OK
1.25 in OK
0.60 (unitless)
0.44 ft OK
Form SW401-Wetland-Rev.6-11l16109 Parts I and II. Project Design Summary, Page 1 of 3

Surface Areas of Wetland Zones
Surface Area of Entire Wetland
Shallow Land
The shallow land percentage is'.
Shallow Water
The shaliow water percentage is:
Deep Pool
Forebay portion of deep pool (pretreatment)
The forebay surface area percentage is:
Non-forebay portion of deep pool
The non-forebay deep pool surface area percentage is:
Total of wetland zone areas
Add or subtract the following area from the zones
Topographic Zone Elevations
Temporary Pool Elevation (TPE)
Shallow Land (top)
Permanent Pool Elevation (PPE)
Shallow Water/Deep Pool (top)
Shallow Water bottom
Most shallow point of deep pool's bottom
Deepest point of deep pool's bottom
Design must meet one of the following two options:
This design meets Option #1,
Top of PPE is within 6" of SHWT, If yes:
SHWT (Seasonally High Water Table)
This design meets Option #2,
Wetland has liner with permeability < 0.01 inlhr, If yes:
Depth of topsoil above impermeable liner
Topographic Zone Depths
Temporary Pool
Shallow Land
Permanent Pool
Shallow Water
Deep Pool (shallowest)
Deep Pool (deepest)
Planting Plan
Are cattails included in the planting plan?
Number of Plants recommended in Shallow Water Area:
Herbaceous (4'cubic-inch container)
Number of Plants recommended in Shallow Land Area:
Herbaceous (4'cubic-inch container), OR
Shrubs (1 gallon or larger), OR
Trees (3 gallon or larger) and Herbaceous (4+ cubic -inch)
Number of Plants provided in Shallow Water Area:
Herbaceous (4'cubic-inch container)
Number of Plants provided in Shallow Land Area:
Herbaceous (4'cubic-inch container)
Shrubs (1 gallon or larger)
Trees (3 gallon or larger) and
Grass -like Herbaceous (4+ cubic -inch)
5,563.00 ft2
2,247.00 ft2
40% %
2,187.00 ft2
39% %
541.00 ft2
10% %
588.00 ft2
11% %
5,563.00 ft2
0.00 ft2
680.00 ft amsl
680.00 ft amsl
679,50 ft amst
678.00 ft amsf
677.00 ft amsl
(Y or N)
ft amsl
Y (Y or N)
12.00 in
0.00 in
6.00 in
24.00 in
36.00 in
N (Y or N)
550
600
96
12 and
622
171
61
F
OK
Insufficient shallow land area.
OK
Insufficient forebay area.
OK
OK
OK
OK
OK
OK
OK
OK
480
More required if not planting shrubs or trees.
More required if not planting herb. and/or trees.
More required if not planting herb. and/or shrubs.
Form SW401-Wetland-Rev.6-11116109 Parts I and II. Project Design Summary, Page 2 of 3

Additional Information
Can the design volume be contained?
Does project drain to SA waters? It yes,
What is the length of the vegetated filter?
Are calculations for supporting the design volume provided in the
application?
Is BMP sized to handle ail runoff from ultimate build -out?
Is the BMP located in a recorded drainage easement with a
recorded access easement to a public Right of Way (ROW)?
The length to width ratio is:
Approximate wetland length
Approximate wetland width
Approximate surface area using length and width provided
Will the wetland be stabilized within 14 days of construction?
Y
(Y or N)
OK
N
(Y or N)
Excess volume must pass through filter.
ft
Y
(Y or N)
OK
Y
(Y or N)
OK
Y
(Y or N)
OK
1.58 :1
OK
95.00 ft
60.00 ft
5,700.00
ftz
This approx, surface area is within this number of square feet
of the entire wetland surface area reported above.
Y
(Y or N)
OK
0
Form SW401-Wetland-Rev.6-11118109
Parts I and 11. Project Design Summary, Page 3 of 3

Permit No.
` (to be provided by DWQ)
III. REQUIRED ITEMS CHECKLIST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a
requirement has not been met, attach justification.
Initials Pagel Plan
Sheet No.
1, Plans (1" - 50' or larger) of the entire site showing:
Design at ultimate build -out,
Off -site drainage (if applicable),
Delineated drainage basins (include Rational C coefficient per basin),
Wetland dimensions (and length to width ratio),
Pretreatment system,
Maintenance access,
Proposed drainage easement and public right of way (ROW),
Overflow device, and
- Boundaries of drainage easement.
2. Plan details (1" = 50' or larger) for the wetland showing:
Wetland dimensions (and length to width ratio)
Pretreatment system,
- Maintenance access,
Proposed drainage easement and public right of way (ROW),
Design at ultimate build -out,
Off -site drainage (if applicable),
Overflow device, and
Boundaries of drainage easement.
3. Section view of the wetland (V = 20' or larger) showing:
Side slopes, 3:1 or lower
Wetland layers
All wetlands: Shallow land depth, shallow water depth, deep pool depth
Option 1, no clay liner: SLWT depth
Option 2, clay liner: Depth of topsoil on top of liner, liner specifications
4. A detailed planting plan (V = 20' or larger) prepared by a qualified individual showing:
A variety of several suitable species (not including cattails),
- Sizes, spacing and locations of plantings,
Total quantity of each type of plant specified,
A planting detail,
The source nursery for the plants, and
Fertilizer and watering requirements to establish vegetation.
*A 5. A construction sequence that shows how the wetland will be protected from sediment until the entire
drainage area is stabilized.
6. The supporting calculations (including drawdown calculations).
7. A copy of the signed and notarized operation and maintenance (0&M) agreement.
MIA 8. A copy of the deed restrictions (if required).
Im_ 9. A soils report that is based upon an actual field investigation and soil borings. County soil maps are not
an acceptable source of soils information.
SW401-Wetland-Rev.6-11116109 Part III, page 1 of 1