SW1140701_401 Certification Application_20140806

T
• • Permit Number: .5LL)I14 /Q1
Ito be provided by DWO)
�?gyp WATpeO�
NC ENR
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
BIORETENTION CELL SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part III) must be printed, filled out and submitted along with all of the required information.
Project name
Contact name
Phone number
Date
Drainage area number
828-252-0575
July 24, 2014
II. DESIGN -INFORMATION
Site Characteristics
Drainage area
67,082 ft2
Impervious area
40,952 ft2
Percent impervious
61.0% %
Design rainfall depth
1.0 inch
Peak Flow Calculations
Is pre/post control of the 1-yr, 24-hr peak flow required?
N (Y or N)
1-yr, 24-hr runoff depth
NIA in
1-yr, 24-hr intensity
NIA in/hr
lpeak flow
N/A ft/sec
Post -development 1-yr, 24hhrpeak flow
N/A ft3/sec
Pre/Post 1-yr, 24-hr peak control
#VALUE! ft3/sec
Storage Volume: Non -SA Waters
_ Q�
Minimum volume required
3,384.0 ft3
_
k `
Volume provided
3,384.0 ft'
OK
4993
Storage Volume: SA Waters
1.5" runoff
et-yr,
If 3
24-hr runoff
Pre -development
Post -development 1-yr, 24-hr runoff
If
ft3
rDstrCP,N`
.'
Minimum volume required
0 ft3
' 2
Volume provided
0
Cell Dimensions
Pending depth of water
12 inches
OK
Pending depth of water
1.00 It
Surface area of the top of the biorelention cell
Length:
3,384.0 ft2
66 it
OK
OK i
Q:tirN;o�
y�cr 1
}
Width:
55 ft
OK ✓
-or- Radius
ft
Media and Soils Summary
Drawdown time, ponded volume
Drawdown time, to 24 inches below surface
Drawdown time, total:
In -situ soil:
Soil permeability
Planting media soil:
Soil permeability
Soil composition
• Sand (by volume)
%Fines (by volume)
%Organic (by volume)
Phosphorus Index (P-Index) of media
Form SW401-Bioretention-Rev.B
June 25, 2010
4.09 hr OK
3.68 hr OK
7.77 fir
NIA in/hr OK
2.00 in/hr OK
88% OK
8% OK
4% OK
Total: 100%
20 (unitless) OK
Parts I and II. Design Summary, Page 1 of 2

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•
• Permit Number:
(to be provided by DWO)
Basin Elevations
Temporary pool elevation
Type of bioretention cell (answer "Y" to only one of the two
following questions):
Is this a grassed cell?
Is this a cell with trees/shrubs?
Planting elevation (top of the mulch or grass sod layer)
Depth of mulch
Bottom of the planting media soil
Planting media depth
Depth of washed sand below planting media soil
Are underdrains being installed?
How many clean out pipes are being installed?
What factor of safety is used for sizing the underdrains? (See
BMP Manual Section 12.3.6)
Additional distance between the bottom of the planting media and
the bottom of the cell to account for underdrains
Bottom of the cell required
SHWT elevation
Distance from bottom to SHWT
Internal Water Storage Zone (IWS)
Does the design include IWS
Elevation of the top of the upturned elbow
Separation of IWS and Surface
Planting Plan
Number of tree species
Number of shrub species
Number of herbaceous groundcover species
Additional Information
Does volume in excess of the design volume bypass the
bioretention cell?
Does volume in excess of the design volume flow evenly distributed
through a vegetated filter?
What is the length of the vegetated filter?
Does the design use a level spreader to evenly distribute flow?
Is the BMP located at least 30 feet from surface waters (50 feet if
SA waters)?
Is the BMP localed at least 100 feet from water supply wells?
Are the vegetated side slopes equal to or less than 3:1?
Is the BMP located in a proposed drainage easement with access
to a public Right of Way (ROW)?
Inlet velocity (from treatment system)
Is the area surrounding the cell likely to undergo development in
the future?
Are the slopes draining to the bioretention cell greater than 20%?
Is the drainage area permanently stabilized?
Pretreatment Used
(Indicate Type Used with an'X" in the shaded cell)
Gravel and grass
(8 inches gravel followed by 3-5 it of grass)
Grassed Swale
Forebay
Other
2362.00 fmsl
Y (Y or N)
N (Y or N)
2362 fmsl
0 inches
2360 fmsl
2ff
0 it
Y (YorN)
0
10
OK
Insufficient mulch depth, unless installing orassed cell.
OK
OK
1 it
2359 fmsl
N/A fmsl
#VALUEIft
N (Y or N) 3 tj ^.F it�1
fmsl
2362 ft ff
ii
Y (Y or N) OK
#VALUE! P,.;cu /vcc ;S :N 41
CrK eiN: ) A-&4 40
1 op1,, F..L.S HwT /r.,: l
be t) jrs: o2 ialy Li
b.�►.M of «��
N
(Y or N)
N/A it
Excess volume must pass through filter.
Duc {{
K1 Q%•S M,�� I i
N/A
(Y or N)
Enter Data
P+cw) eG �+j1
Y
(Y or N)
OK
M"^ �c1�t�I^• rinad�l Sift
Y
Y
(YorN)
(YorN)
OK
OK
C P•itni{cl', C<W�^,Qr.r•�,
7.95 fUsec
Insufficient inlet velocity unless energy dissipating devices are/
being used.
I
N
(Y or N)
OK
N
(Y or N)
OK
Y
(Y or N)
OK
R PM�11 -pt.5) i�D
#VALUE! �}
- P' f
�•��� ti,� Jvc/cjc
X
�,� �t✓� utcf
Form SW401-Bioretention-Rev.8
June 25, 2010
Parts I and II. Design Summary, Page 2 of 2

15,
Permit No:
(to be assigned by DWO)
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 projectnitial in the space provided
to indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial belowlf a
requirement has not been met, attach justification.
Page/ Plan
Initig4s
Sheet No.
X3
e' 10
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),
- Cell dimensions,
- Pretreatment system,
- High flow bypass system,
- Maintenance access,
- Recorded drainage easement and public right of way (ROW),
- Clean out pipe locations,
- Overflow device, and
- Boundaries of drainage easement.
2. Plan details (1" = 30' or larger) for the bioretenlion cell showing:
- Cell dimensions
- Pretreatment system,
- High flow bypass system,
- Maintenance access,
- Recorded drainage easement and public right of way (ROW),
- Design at ultimate build -out,
- Off -site drainage (if applicable),
- Clean out pipe locations,
- Overflow device, and
- Boundaries of drainage easement.
C,j
- Indicate the P-Index between 10 and 30
3. Section view of the bioretenlion cell (1" = 20' or larger) showing:
- Side slopes, 3:1 or lower
- Underdrain system (if applicable), and
- Bioretention cell layers [ground level and slope, pre-treatment, ponding depth, mulch depth, fill media
WA
depth, washed sand, filter fabric (or choking stone if applicable), #57 stone, underdrains (if applicable),
,,,,,"J(c:,S
SHWT level(s), and overflow structure]
55
Ix "'xA4. A soils report that is based field investigation,
upon an actual soil borings, and infiltration tests. The
J0 „r:l
I results of the soils report must be verified in the field by DWQ, by completing & submitting the soils
- W investigation request form. County soil maps are not an acceptable source of soils information. All
b� S`ID1°`
elevations shall be in feel mean sea level (fmsl). Results of soils tests of both the planting soil and the in
hJ b.n Cc„v
rcacx)
situ soil must include:
Soil permeability,
4ly ar +t�K Soil composition (%sand °% 4,A fines"%prganic), and
! ( J
Si3
N/A
P-index.
5. A etailed planting plan (1' = 20' or larger) prepared by a qualified individual showing:
A variety of
qrV0t
suitable species,
Sizes, spacing and locations of plantings,
- Total quantity of each type of plant specified,
- A planting detail,
- The source nursery for the plants, and
�'r7y
(`Io4
Fertilizer and watering requirements to establish vegetation.
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C-S°5
6. A construction sequence that shows how the bioretenlion cell will be protected from sediment until the
7 k
entire drainage area is stabilized.
7. The supporting calculations (including underdrain calculations if applicable)
Sj3 i„ s �Ikl
8. A copy of the signed and notarized inspection and maintenance (I&M) agreement.
9. A copy of Ithe deed restriction. ' I I. N
t v,
51"r�J
Form SW401-Bioretention-Rev.7 1 Part III, Page 1 of 1