SW8041210_COMPLIANCE_20070202

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW,on4a.{TJ
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS �
❑ HISTORICAL FILE
COMPLIANCE EVALUATION INSPECTION
DOC DATE
oqv__Y/)aU
YYYYMMDD

STORMWATER DIVISION CODING SHEET
NCG PERMITS
PERMIT NO.
/v U&
DOC TYPE
❑ HISTORICAL FILE
❑ MONITORING REPORTS
DOC DATE
❑
YYYYMMDD

r
Permit No 5-W 8 W 2-/a
(to be provided b,, DVVQ)
State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
INFILTRATION BASIN SUPPLEMENT
Thts form may be photocopted for use as an original
DWQ Stormwater Management Plan Review
A complete stormwater management plan subrruttal includes a stormwater management permit application, an
infiltration basin supplement for each system, design calculations, soils report and plans and specifications
showing all stormwater conveyances and system details
I. PROJECT INFORMATION
Protect Name 31 �3 ✓ Ile-Ale.,,e c_ --- - - -- -- --
Contact Person ; , 11, k P a Phone Number -73,1 --
This worksheet applies to Basin No
(as identified on plans)
in Drainage Area I
(from Form SWU-101)
11. DESIGN INFORMATION - Attach supporting calculations/documentation The soils report must be
based upon an actual field investigation and soil borings County soil maps are not an acceptable
source of soils information All elevations shall be in feet mean sea level (fmsl)
Soils Report Summary
Soil Type
Infiltration Rate
SHWT Elevation
Basin Design Parameters
Design Storm
Design Volume
Drawdown Time
Basin Dimensions
Basin Size
Basin Volume Provided
Basin Elevations
'Bottom Elevation
storage Elevation
Top Elevation
7 Qve,
Qr cf/hr/sf (circle appropriate units)
f1 fmsl (Seasonal High Water Table elevation)
inch (1 S inch event for SA waters, 1 inch event for others)
7 G G- c f
G, 0 :!�: days
-- ft x
r� c f
r L �q-!
cs
L, V
17, G fmsl
1-7r E� fmsl
I ta, 4 fmsI
ft = I LO / sq ft (bottom dimensions)
Fotm SWU-103 Rev 3 99 Page 1 of 3

III. REQUIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices Manual
(N C Department of Environment, Health and Natural Resources, February 1999) and Administrative Code
Section 15 A NCAC 2H 1008
Initial in the space provided to indicate that the following design requirements have been met and supporting
documentation is attached If the applicant has designated an agent in the Stormwater Management Pernut
Application Form, the agent may initial below Attach justification if a requirement has not been met.
Applicants Initials
. a
System is located 50 feet from class SA waters and 30 feet from other surface waters
b
System is located at least 100 feet from water supply wells
c
Bottom of system is at least 2 feet above the seasonal high water table
d
Bottom of the system is 3 feet above any bedrock or impervious soil horizon
e
System is not sited on or in fill material or DWQ approval has been obtained
f
System is located in a recorded drainage easement for the purposes of operation and
(7o '35 r)6
maintenance and has recorded access easements to the nearest public right-of-way
g
Drainage area for the device is less than 5 acres
h
Soils have a minimum hydraulic conductivity of 0 52 inches per hour and soils report is
r
attached
i
System captures and infiltrates the runoff from the first 10 inch of rainfall (1 5 inch event
for areas draining to SA waters ) Design volume and infiltration calculations attached
A j
System is sized to take into account the runoff at the ultimate built -out potential from all
surfaces draining to the system, including any off -site drainage Calculations attached
k
All side slopes stabilized with vegetated cover are no steeper than 3 1 (H V)
1
A pretreatment device such as a catch basin, grease trap, filter strip, grassed swale or
sediment trap is provided
in Bottom of the device is covered with a layer of clean sand to an average depth of 4 inches
or dense vegetative cover is provided
n Vegetated filter is provided for overflow and detail is shown on plans (Required minimum
length is 50 feet for SA waters, 30 feet for other waters)
�A. o Flow distribution mechanism within the basin is provided
p A benchmark is provided to determine the sediment accumulation in the pretreatment
device
q Runoff in excess of the design volume bypasses off-line systems (bypass detail provided)
r r System is designed to draw down the design storage volume to the proposed bottom
elevation under seasonal high water conditions within five days A soils report and all
pertinent draw -down calculations are attached
s Plans ensure that the installed system will meet design specifications (constructed or
restored) upon initial operation once the project is complete and the entire drainage area is
stabilized
Form SWU-103 Rev 3 99 Page 2 of 3

IV INFILTRATION BASIN OPERATION AND MAINTENANCE AGREEMENT
1 After every runoff producing rainfall event and at least monthly inspect the infiltration system for erosion,
trash accumulation, vegetative cover, and general condition
2 Repair eroded areas immediately, re -seed as necessary to maintain adequate vegetative cover, mow
vegetated cover to maintain a maximum height of six inches, and remove trash as needed
3 After every runoff producing rainfall event and at least monthly inspect the bypass, inflow and overflow
structures for blockage and deterioration Remove any blockage and repair the structure to approved
design specifications
4 Remove accumulated sediment from the pretreatment system and infiltration basin annually or when
depth in the pretreatment unit is reduced to 75% of the original design depth The system shall be restored
to the original design depth without over -excavating Over -excavating may cause the required water
table separation to be reduced and may compromise the ability of the system to perform as designed
Removed sediment shall be disposed of in an appropriate manner and sha11 not be handled in a manner
that will adversely impact water quality (i a stockpiling near a stormwater treatment device or stream,
etc )
A benchmark shall be established in the pretreatment unit The benchmark will document the original
design depth so that accurate sediment accumulation readings can be taken The measuring device used
to deternune the depth at the benchmark shall be such that it will give an accurate depth reading and not
readily penetrate into accumulated sediments
When the design depth reads feet in the pretreatment unit, the sediment shall be
removed from both the pretreatment unit and the infiltration basin
5 If the Division determines that the system is failing, the system will immediately be repaired to onginal
design specifications if the system cannot be repaired to perform its design function, other stormwater
control devices as allowed by NCAC 2H 1000 must be designed, approved and constructed
I acknowledge and agree by my signature below that I am responsible for the performance of the five
maintenance procedures listed above I agree to notify DWQ of any problems with the system or pnor to any
changes to the system or responsible party
Print Name and Title 1 "
Address
�7 3 �� b Date i _ /
>
!� a 7
Phone
Signature
Note The legally resfonsible%arry should not be a homeowners association unless more than 50% of the lots have been sold and
resident of the subdivision has been named the president
et
a Nou``blic for the State of _ County of
do hereby certify that h "-T personally appeared before me this _
day of 7 and acknowledge the due execution of the forgoing infiltration basin maintenance
requirements Witness my hand and official seal,
SEAL
My commission expires -2 g"&�
Form S WU-103 Rev 3 99 Paoe 3 of 3

INFILTRATION BASIN ANALYSIS
PROJECT NUMBER 041210 feb05
PROJECT NAME 313 Greenville Avenue
DRAINAGE BASIN Cape Fear
RECEIVING STREAM Bradley Creek
Index No
SITE AREA 1 21 acres
IMPERVIOUS AREA CALCULATION
BUILDINGS
PARKING/ASPHALT
CONCRETE
FUTURE
TOTAL
% IMPERVIOUS, i= I i;'I NI 37i 9°/a
ELEVATION OF SEASONAL HIGH WATER TABLE
REPORTED INFILTRATION RATE
SURFACE AREAS AND ELEVATIONS
FILENAME S IWQSIINBASIN1041210 feb05 WK1
DATE 13-Feb-05
REVIEWER L Lewis
CLASS SC
If ORW, is site within the 575' AEC?
DRAINAGE AREA I1,111 h''' , 52853 SF
Rational C
6984
1
8653
1
3388
1
1000
1
F--200251
50
C VllWNU I I 17750
Place a "1" here if Rational
IIIII I I 11111
RV= 05+ 009 (I) =
1;11h1 lil k 039
I'lI�'r,l
14 FEET MSL
hhhiii� II ,
12 INCHES/HOUR
or 0 000278 FPS
Elev (ft) Area, sq ft Inc Volume Acc Volume
BOTTOM 17 1601
0
0 0
TOP 178 2966 18268 18268
VOLUME / DEPTH / DRAWDOWN CALCULATION
DESIGN STORM, INCHES
DESIGN VOLUME
TOTAL VOLUME AVAILABLE
DEPTH OF RUNOFF
TIME TO DRAWDOWN
25 YEAR 24 HOUR STORM N/A
Intensity, i = 33 inches / hour
Qr=CIA
Qp through the bottom of the basin=
10 YEAR 10 MIN HIGH INTENSITY EVENT
Intensity, i = 6 3 inches / hour
Volume for 10 yr 10 min event =
'I'' I I 11JAI
1722II CUBIC FEET
1826 8 CUBIC FEET
0 80' FEET
1' 111 HOURS MUST BE <120
020 CFS
044 CFS Must be > Qr
2307 45 CF < 1826 8 CF
COMMENTS
Volume and drawdown are (not) within Design Requirements

0
INFILTRATION BASIN ANALYSIS
PROJECT NUMBER 041210 apr05
PROJECT NAME
313 Greenville Avenue
DRAINAGE BASIN
Cape Fear
RECEIVING STREAM
Bradley Creek
Index No
SITE AREA 1 21 acres
IMPERVIOUS AREA CALCULATION
BUILDINGS
PARKING/ASPHALT
CONCRETE
FUTURE
TOTAL
% IMPERVIOUS, 1= 1 37;9%1
ELEVATION OF SEASONAL HIGH WATER TABLE
REPORTED INFILTRATION RATE
SURFACE AREAS AND ELEVATIONS
FILENAME S 1WQS11NBASIN1041210 apr05 WK1
DATE 28-Apr-05
REVIEWER L Lewis
CLASS Sc
If ORW, is site within the 575' AEC?
DRAINAGE AREA I I'll 1''1111'1,111111'!1II 853 SF
Rational C
6984 1
8653 1
3388 1
1000 1
7� 20025 c 1IINili �11,11IiJJ, 050
Place a "1" here if Rational I' I I iN9 ' i 11''i
RV= 05+ 009 (1) _ !�11111,i111i110'39
"I'I� II14 FEET MSL
12 INCHESIHOUR
or 0000278 FPS
Elev (ft) Area, sq ft Inc Volume Acc Volume
BOTTOM
17 1601
175 2359
TOP 178 2966
VOLUME / DEPTH 1 DRAWDOWN CALCULATION
DESIGN STORM, INCHES
DESIGN VOLUME
TOTAL VOLUME AVAILABLE
DEPTH OF RUNOFF
TIME TO DRAWDOWN
25 YEAR 24 HOUR STORM NIA
Intensity, E = 33 inches / hour
Qr=CiA=
Qp through the bottom of the basin=
10 YEAR 10 MIN HIGH INTENSITY EVENT
Intensity, i = 6 3 inches / hour
Volume for 10 yr 10 min event =
0
990 990
799 1789
11111" 1
11 'I 11722 CUBIC FEET
Nl; 1 1789 CUBIC FEET
0 78 FEET
1 1 HOURS MUST BE <120
020 CFS
000 CFS Must be > Qr
2307 45 CF < 1788 75 CF
COMMENTS
Volume and drawdown are (not) within Design Requirements

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0