SW8051142_COMPLIANCE_20080228

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW ,&2S7d
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE
COMPLIANCE EVALUATION INSPECTION
DOC DATE
YYYYMMDD

CONSULTING, PA
�J
I 7332 Cotesworth Drive
J � � Wilmington, NC 28405
[phone] Fax [phone]
r
PLANNING - ENGINEERING - CONSTRUCTION MANAGEMENT
February 28, 2008
Mr. Ed Beck
NCDENR - DWQ
127 Cardinal Drive Extension
Wilmington, NC 28405-3845
Stormwater Project Number SW8 051142
Project Name: Futch Creek Kingdom Hall
Futch Creek Road
New Hanover County, NC
Designer's Certification
I, Bradford Sedgwick, PE, as a duly registered Professional Engineer in the State of North
Carolina, having been authorized to observe (periodically) the construction of the project,
Futch Creek Kingdom Hall (Project)
for Mr. Gerald Evans, Presiding Overseer for the Hampstead Congregation of Jehovah's
Witnesses (Project Owner) hereby state that, to the best of my abilities, due care and
diligence was used in the observation of the project construction such that the construction
was observed to be built within substantial compliance and intent of the approved plans
and specifications.
Noted deviations from approved plans and specifications:
1. There is some ongoing vegetative slope stabilization ongoing during the time of inspection.
2. Due to the severe drought during the past few months some of the planting in the bio
retention area are in poor shape. Further evaluation of the plants is required when the
weather improves. Th.- Own has been informed that replacement ofaud �prr g,,,9fthe planting
ray
may be re e •(x C,q
Sp O f E,s
Signature QQ y
W 45� r
Registration Number 26378
Date 2128/08 � �O�O�"""""��
�,,,, % SE�Ca
Attachment: Certification Requirements Checklist
RECEIVmI7
BY:
MAR 0 3 2008

`.
r t

State Stormwater Management Systems
Permit No. SW8 051142
Certification Requirements:
1. The drainage area to the system contains approximately the permitted
acreage.
�2. The drainage area to the system contains no more than the permitted
amount of built -upon area.
13K3. All the built -upon area associated with the project is graded such that the
runoff drains to the system.
4. All roof drains are located such that the runoff is directed into the system.
�5. The basin elevations are per the approved plans.
6. The basin is located per the approved plans.
7. A Trash Rack is provided on the outlet/bypass structure.
8. The required number of landscape plantings has been provided and are
correctly located in the basin per the approved plans.
9. Vegetated slopes are no steeper than 3:1.
10. The inlets are located per the approved plans and do not cause short-
circuiting of the system.
11. All required design depths are provided.
W12. All required parts of the system are provided.
VD 3. The required system dimensions are provided per the approved plans.
cc: NCDENR-DWQ Regional Office
Tony Roberts, New Hanover County Building Inspections
Perna 7 of 7

Bioretention Basin Design File Name: S:IWQSIBIORETENTION1051142.WK1
Project Number: SW8 051142 Date 31-Jul-2006
Project Name: Futch Creek Kingdom Hall
Receiving Stream: Futch Creek Classification: SA
Drainage Basin: Cape Fear Index Number: CPF24 18-87-19
Minimum Surface Area
c=.95 for BUA, c=.25 for grass
Minimum
Provided
Basin # DA
BUA Sum C x A
BR Area
Area
1 53142
33756 35226.90
2466
4327 sf
2
0.00
0
sf
3
0.00
0
sf
4
0.00
0
sf
5
0.00
0
sf
Volume Reauired
Basin #
Percent
BUA
Design Storm Rv Value
Required
Volume
1
_
63.52%
1.5 0.62
4130
2
#DIVIO!
#DIV/O!
#DIV/O!
3
#DIV/O!
#DIV/O!
#DIV/O!
4
#DIVIO!
#DIV/O!
#DIV/O!
5
#DIV/O!
#DIV/O!
#DIV/O!
Volume Provided
Basin #
Bottom
Area
Bottom
Elevation
Top
Area
Top
Elevation
Volume Prov.
@Top
Total Vol
Provided
BR
4327
29.000
4897.00
29.70
3228
SW
1323
29.000
1646.00
29.70
1039
4267.55
3
0
#DIV/01
4
0
#DIV/O!
5
0
#DIV/01
Planting Guidelines
Basin #
Min. # Plants
Ratio of
Prov. # Trees Prov. # Shrubs Shrubs/Trees
1
99
25 75 3.00
(must be 2-3)
2
#DIV/O!
(must be 2-3)
3
0
#DIV/O!
(must be 2-3)
4
0
#DIV/O!
(must be 2-3)
5
0
#DIV/O!
(must be 2-3)
Comments
ft
ft
ft
ft
ft

Basin #1
Stormwater Treatment Worksheet
Total Basin Area 'ra := 1.22 acres Impervious Area la := .78 acres
% Impervious Area I := 1a • l00 I = 63.934 Ye
Ta
Runoff Coefficient Claculation
Kenansville/Stallings (B)
Lawns (Good)
0A0
0.380
0.15
KenamAlle/Stallings (B)
Bioretention (Good)
0.35
0.060
0.02
Kenansville/Stallings (B)
Buildings
0.95
0.160
0.15
Kenansville/Stallings (B)
Pavement
0.95
0.620
0.59
1.220
0.91
Wtc =
0.9
=
0.7
1.22
Use
0.7
Bio-Retention Surface Area
Min. Surface Area without Sand Bed
Sa := .07•Ta•0.7.43560 Sa = 2604.017 3gFt Min.
1.5" Storm Volume to be Controlled
Schueler (1987) 'Simple Method" of volume calculation
Rv := 0.05 + 0.009•
Rv = 0.625
Volume:= 1.5•Rv Ta•43560 Volume = 4154.535 ;uFt
12
Bio-retention Stage 1 Storage Calculation
(4327sgft BRA area provided)
RECEIVED
MAY 0 8 2006
DWQ
PROJ #1
Side slope above bottom elevation
3
Stage/Storage
Contour
BRA Area
(SF)
Swale Area
(SF)
Total Area
(SF)
Incremental
Volume (CF)
Cumulative
Volume, S
(CF)
29.00
4,327.0
1,323.0
6,650.0
0
0
Bottom Elev.
29.50
4,730.7
1,550.2
6,280.9
2,983 1
2,983
29.70
1 4,897.2
1 1,646.2
6,543.4
1 1,282
4,265
Overflow Elev.
IThe_Bio=retention_and Swale_have_been_added toaether
in_the Contour Area table
1 of 2

1.5" Treatement Volume Drawdown
Infiltration rate provised
Infiltration Rate inch/hour Ir := 1.5 by ECS.
Bottom Area Ap := 4327 sf (BRA area only)
Ir
Q:= Ap Q=0.15
12.3600
Time := VolumeTime = 7.681 :iours Less that the 12 hour requirement
Q•3600
Bio-retention Planting Calculation
Minimum 1000 trees and shrubes per area of bio-retention
at a rate of 3 shrubs per per tree
4327
plantings :_ 43560 • 1000 plantings = 99.3
1
trees := plantings— trees = 24.8
4
shrubs := plantings. 3 shrubs = 74.5
4
Bioretention should be planted with 25 trees and 75 shrubs
2of2

Bioretention Basin Design File Name: S:IWQSIBIORETENTION1051142.WK1
Project Number: SW8 051142 Date 21-Jan-2006
Project Name: Futch Creek Kingdom Hall
Receiving Stream: Futch Creek Classification: SA
Drainage Basin:. Cape Fear ,., Index Number:
Minimum Surface Area
c=.95 for BUA, c=.25 for grass
Minimum
Provided
Basin # DA
BUA Sum C x A
BR Area
Area
1 53142
33756 35226.90
2466
3800 sf
2
0.00
0
sf
3
0.00
0
sf
4
0.00
0
sf
5
0.00
0
sf
Volume Reauired
Percent
Required
Basin #
BUA
Design Storm Rv Value
Volume
1
63.52%
1.5 0.62
4130
2
#DIV/O!
#DIV/O!
#DIVIO!
3
#DIV/O!
#DIV/O!
#DIV/O!
4
#DIV/O!
#DIV/O!
#DIV/O!
5
#DIV/O!
#DIV/O!
#DIV/O!
Volume Provided
Bottom
Bottom Top Top Volume Prov.
Req. Vol. Met
Basin # Area
Elevation Area Elevation @Top
@ elev.
1 3800
26.000 4576.00 27.00 4188
26.99 ft
2
0
#DIV/O! ft
3
0
#DIV/O! ft
4
0
#DIV/O! ft
5
0
#DIV/O! ft
Plantina Guidelines
Basin #
Min. # Plants
Ratio of
Prov. # Trees Prov. # Shrubs Shrubs/Trees
1
87
22 66 3.00
(must be 2-3)
2
0
#DIV/O!
(must be 2-3)
3
0
#DIV/01
(must be 2-3)
4
0
#DIV/O!
(must be 2-3)
5
0
#DIV/O!
(must be 2-3)
Comments
Per Soils report, SHWT is 24" BEG, so bottom of basin should be at the existing surface.