SW8990236_COMPLIANCE_19990811

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW
DOC TYPE
El CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE
COMPLIANCE EVALUATION INSPECTION
DOC DATE-
YYWMMDD

Compliance Inspection Report
Permit: SW8990236 Effective: 08/11/99 Expiration: 08/11/13 Owner: J&S Miller Inc
Project: Superior Center
County: New Hanover Carolina Beach Rd
Region: Wilmington
Contact Person: James D Miller Title: Pres
Directions to Project:
170' north of Christa Drive on east side of US 421.
Type of Project: State Stormwater - HD - Detention Pond
Drain Areas: 1 - (Mott Creek (Todds Creek)) (03-06-17 } ( C;Sw)
On -Site Representative(s):
Related Permits:
Inspection Date: 06/1012013 Entry Time: 09:00 AM
Primary Inspector: Christine Nelson
Secondary Inspector(s):
Reason for Inspection: Routine
Permit Inspection Type: State Stormwater
Facility Status: ❑ Compliant ■ Not Compliant
Question Areas:
State Stormwater
(See attachment summary)
Wilmington NC 28412
Phone: [phone]
Exit Time: 09:30 AM
Phone:[phone]
Inspection Type: Transfer. Renewal
Page: 1

Permit: SW8990236 Owner - Project: J&S Miller Inc
Inspection Date: 06/10/2013 Inspection Type: Transfer Renewal Reason for Visit: Routine
Inspection Summary:
The permit expires on August 11, 2013 and a renewal application must be submitted 180 days prior to the expiration.
Section 11.7 of the permit requires the certification to be submitted prior to the operation of the facility. The certificiation
does not appear to have been submitted.
Section 11.9 of the permit requires a modification when there is a transfer of ownership. The permittee dissolved on
12/5/2006 without transfering the permit to the current property owners.
Please submit the completed certification, renew the permit, and transfer the permit to the current owners.
Page: 2

Permit: SW8990236 Owner - Project: AS Miller Inc
Inspection Date: 06/10/2013 Inspection Type: Transfer Renewal
c:i., o.. 1^...
Is the permit active?
Signed copy of the Engineer's certification is in the file?
Signed copy of the Operation & Maintenance Agreement is in the file?
Copy of the recorded deed restrictions is in the file?
Reason for Visit. Routine
Comment: The permit expires on August 11, 2013 and a renewal application must be
submitted 180 days prior to the expiration.
Section 11.7 of the permit requires the certification to be submitted prior to the operation
of the facility. The certificiation does not appear to have been submitted.
Built Upon Area
Is the site BUA constructed as per the permit and approval plans?
Is the drainage area as per the permit and approved plans?
Is the BUA (as permitted) graded such that the runoff drains to the system?
Comment:
CIRI RM---...--
Are the SW measures constructed as per the approved plans?
Are the inlets located per the approved plans?
Are the outlet structures located per the approved plans?
Yes No NA NE
Yes No NA NE
Yes No NA NE
❑❑❑■
❑ ❑ ❑ ■
❑ ❑ ❑ ■
Comment:
Operation and Maintenance Yes No NA NE
Are the SW measures being maintained and operated as per the permit requirements? ❑ ❑ ❑ ■
Are the SW BMP inspection and maintenance records complete and available for review or provided to DWQ ❑ ❑ ❑ ■
upon request?
Comment:
Other Permit Conditions Yes No NA NE
Is the site compliant with other conditions of the permit?
Comment: Section 11.9 of the permit requires a modification when there is a transfer of
ownership. The permittee dissolved on 12/5/2006 without transfering the permit to the
current property owners.
Other WQ Issues
Is the site compliant with other water quality issues as noted during the inspection?
Comment:
Yes No NA NE
■ ❑ ❑ ❑
Page: 3

Compliance inspection Report
Permit: SW8990236 Effective: 08/11/99 Expiration
County: New Hanover
Region: Wilmington
Contact Person: James D Miller Title: Pres
Directions to Project:
Type of Project: State Stormwater - HD - Detention Pond
Drain Areas: 1 - (Mott Creek (Todds Creek)) (03-06-17) ( C;Sw)
On -Site Representative(s):
Related Permits:
Inspection Date: 05/09/2009 Entry Time: 08:30 AM
Primary Inspector: David W Cox
Secondary Inspector(s):
Reason for Inspection: Routine
Permit Inspection Type: State Stormwater
Facility Status: ❑ Compliant ■ Not Compliant
Question Areas:
® State Stormwater
(See attachment summary)
Owner: J&S Miller Inc
Project: Superior Center
Exit Time: 09:00 AM
Phone: [phone]
Phone: [phone]
Inspection Type: Stormwater
Page: 1

Permit: SW8990236
Inspection Date: 05/09/2009
Owner - Project: J&S Miller Inc
Inspection Type: Stormwater
Reason for Visit: Routine
Inspection Summary:
In order to correct the following deficiencies you must perform the following:
1. Submit the required Engineers Certificate that was required uupon completion of the stormwater system.
2. Control cattail growth to a minimum of 50%.
Is the permit active?
Q
Cl
❑
Signed copy of the Engineer's certification is in the file?
❑
®
❑
❑
Signed copy of the Operation & Maintenance Agreement is in the file?
SO
n
n
Copy of the recorded deed restrictions is in the file?
❑
❑
❑
■
Comment: This office has not received a copy of the engineers certification
SW Measures
Yes
No
NA
NE
Are the SW measures constructed as per the approved plans?
■
❑
❑
❑
Are the inlets located per the approved plans?
❑
❑
❑
Are the outlet structures located per the approved plans?
®❑
❑
0
Comment:
Operation and Maintenance
Yes
No
NA
NE
Are the SW measures being maintained and operated as per the permit requirements?
n
®❑
n
Are the SW BMP inspection and maintenance records complete and available for review or provided to DWQ
❑
n
00
upon request?
Comment: Cattails have exceeded the 50% allowance required by the operation and
maintenance agreement.
Page: 2

SUPERIOR CENTER
NEW HANOVER COUNTY
STORMWATER MANAGEMENT CALCULATIONS
STORMWATER
E C E C V E
JUN301999
D E M
PROJ #
February 1999
Revised June 1999
i •.
cItcp�...,..••• tit ��,;
Prepared By:
JOSEPH S. HILL, JR. and ASSOCIATES
CONSULTING ENGINEERS and PLANNERS
1602 Harbour Drive
Wilmington, North Carolina 28401
[phone]
SUPERIOR CTR.STWR CUR

SUPERIOR CENTER
Detention Pond Calculations
2. Forebay Calculations
Outlet Protection Design - 18" 0 Pipe
SUPERIOR CfR.SWR CVR.doc

SUPERIOR CENTER
Stormwater Detention Pond Calculations
Stormwater runoff from the project will be retained in a wet detention
pond. This pond will store the runoff generated by 1 inch of rainfall. The stored
runoff will be discharged over a period of 3.7 days.
The pond area required to remove 90% of total suspended solids was
calculated using the SA/DA Percentage Chart (see chart) for North Carolina
coastal regions.
Runoff Calculations
Impervious Surfaces -
Building Rooftop - 23,200 SF
Asphalt Street & Parking = 26,739 SF
Total Impervious Surfaces = 49,939 SF
Total Area = 1.7977 Ac. = 78,308 SF
Total Pervious Area = 28,369 SF
1" Runoff from Impervious Surfaces = 0.083' x 49,939 SF = 4,145 CF
1" Runoff from Pervious Surfaces = 0.2 x 0.083' x 28,369 SF = 471 CF
Total runoff to be stored in pond = 41616 CF
= 34,620 Gals
Detention Pond Calculations
Pond Surface area @ Temporary Pool Elev. of 38.7' = 7,038 SF
Pond Surface area @ Permanent Pool Elev. of 38.0' = 6,192 SF
Average Pond Surface Area = 6,615 SF
Pond Storage Volume = 6,615 SF x 0.7' Depth ="-4,630 CF
Total Watershed Area = 1.7977 AC. = 78,308 SF
SUPERIOR CTR.SfWR CALC.doc
Page I of 4

Impervious % = 49,939 SF = 78,308 SF = 63.8%
Pond Depth = 5.0'
SA/DA % required for 90% solids removal @ 5.0' Depth (see chart)
= 4.6%
4.6% x 1.7977 AC. = 0.10 AC. = 4,356 SF
Pond surface area @ Permanent Pool Elev. of 27.3' = 6,192 SF
Pond is therefore adequate for 90% TSS removal.
-Orifice Disc`aege Cate Calculations
Use V diameter orifice for outlet
Calculate average discharge rate and time to lower orifice head from 0.7' to 0.6%
0.1' pond height x 6,615 SF average pond area x 7.5 gal/Ft3
= 4,961 Gallons Storage
Average head on orifice from 0.7' to 0.6' = 0.65'
Average discharge rate @ 0.65' head:
Q(GPM) = (449)c A-/2gh
Q(GPM) = Volume discharged in gallons per minute
c= discharge coefficient = 0.6
A = orifice area in square feet
g = gravity = 32.2
h = head above center of gravity
Q(GPM) _ (449)(.6)(.0055)-/(2)(32.2)(0.65)
Q = 9.6 GPM
Time required to lower pond 0.1' @ 0.65' average head:
T = 4,961 Gal. = 9.6 GPM = 517 minutes
9.6 GPM vs 517 minutes plotted on curve (see discharge curve).
SUPERIOR CTR.STWR CALC.doc Page 2 of 4

Discharge rate and time to lower head from 0.6' to 0.5':
Q = 8.8 GPM
T = 4,961 Gal. 8.8 GPM = 564 minutes
8.8 GPM vs 1,081 minutes plotted on curve.
Discharge rate and time to lower head from 0.5' to 0.4':
Q = 8.0 GPM
T = 4,961 Gal. = 8.0 GPM = 620 minutes
8.0 GPM vs 1,701 minutes plotted on curve.
Discharge rate and time to lower head from 0.4' to 0.3':
Q = 7.0 GPM
T = 4,961 Gal. = 7.0 GPM = 709 minutes
7.0 GPM vs 2,410 minutes plotted or, curve.
Discharge rate and time to lower head from 0.3' to 0.2':
Q = 5.9 GPM
T = 4,961 Gal. = 5.9 GPM = 841 minutes
5.9 GPM vs 3,251 minutes plotted on curve.
Discharge rate and time to lower head from 0.2' to 0.1':
Q = 4.6 GPM
T = 4,961 Gai. = 4.6 GPM = 1,078 minutes
4.6 GPM vs 4,329 minutes plotted on curve.
Discharge rate and time to lower head from 0.1' to 0.0':
Q = 2.7 GPM
T = 4,961 Gal. = 2.7 GPM = 1,837 minutes
2.7 GPM vs 6,166 minutes plotted on curve.
The outlet structure will discharge the total calculated runoff volume of
34,620 gallons in approximately 3.7 days (see Orifice Discharge Curve).
SUPERIOR CTR.STWR CALCAOC Page 3 of 4

d
�
�
-/--
d
..� ,
m
�
7
. /
. .
0
n.
=---
Q k 2
¥
« o m
� Q �
i
2
}
w
XL
¥
» a
0
\
�
.
tb
Q
>
w O
C
�
g
CJC)
• S
o
� �
---- __.
N4/
o � �
■
m

SA/DA - 85%.TSS REMOVAL WITH 30' VEGETATIVE FILTER
IMPER.% 3.OFT 3.5FT 4-OFT 4.5FT 5.OFT 5.5FT 6.OFT 6.5FT 7-OFT 7.5FT
10%
.9
.8
.7
.6
.5
20%
1.7
1.3
1.2
1.1
1.0
.9
.8
.7
.6
.5
30%
2.5
2.2
1.9
1.8
1.6
1.5
1.3
1.2
1.0
.9
40%
3.4
3.0
2.6
2.4
2.1
1.9
1.6
1.4
1.1
1.0
50%
4.2
3.7
3.3
3.0
2.7
2.4
2.1
1.8
1.5
1.3
60%
5.0
4.5
3.8
3.5
3.2
2.9
2.6
2.3
2.0
1.6
70%
6.0
5.2
4.5
4.1
3.7
3.1
2.9
2.5
2.1
1.8
80%
6.8
6.0
5.2
4.7
4.2
3.7
3.2
2.7
2.2
2.0
90%
7.5
6.5
5.8
5.3
4.8
4.3
3.8
3.3
2.8
1.3
100%
8.2
7.4
6.8
6.2
5.6
5.0
4.4
3.8
3.2
2.6
SA/DA - > 90% TSS REMOVAL
FOR WET DETENTION WITHOUT VEGETATIVE FILTER
IMPER.% 3.OFT 3.5FT 4.OFT 4.5FT 5.OFT 5.5FT 6.OFT 6.5FT 7.OFT 7.5FT
10%
1.3
1.0
.8
.7
.6
.5
.4
.3
.2
.1
200
2.4
2.0
1.8
1.7
1.5
1.4
1.2
1.0
.9
.6
30%
3.5
3.0
2.7
2.5
2.2
1.9
1.6
1.3
1.1
.8
40%
4.5
4.0
3.5
3.1
2.8
2.5
2.1
1.8
1.4
1.1
50%
5.6
5.0
4.3
3.9
3:5.
3.1
2.7
2.3*
1.9
1.5
60%
7.0
6.0
5.3
4.8
4.3
3.9
3.4
2.9
2.4
1.9
70%
8.1
7.0
6.0
5.5'
.0
4.5
3.9
3.4
2.9
2.3
80%
.9.4
8.0
7.0
6.4
5.7
5.2
4.6
4.0
3.4
2.8
90%
10.7
9.0
7.9
7.2
6.5
5.9
5.2
4.6
3..9
3.3
100%
12.0
10.0
8.8
8.1
7.3
6.6
-5.8
5.1
4'.3
3.6
6 `t �,

SUPERIOR CENTER
Forebay Calculations
Provide 20% of Total Permanent Pool volume including area of forebay
construction:
Permanent Pool Volume:
Pool Area @ Elev. 38.0' = 6,192 SF
Pond Area @ Elev. 33.0' = 700 5r
Pond Average Area = 3,446 SF
3,471 SF x 5.0' Depth = 17,230 CF Permanent Pond Volume
171230 CF x 0.2 = 3,446 CF Forebay Volume Required
Forebay Volume:
Forebay Area @ Elev. 37.8' = 11728 SF
Forebay Area @ Elev. 34.0' = 306 SF
Forebay Average Area = 11017 SF
1,017 SF x 3.8' Depth = 3,865 CF Forebay Volume
31865 CF = 17,230 CF = 22%
Forebay = 22% of Permanent Pond Volume
SUPERIOR CTR.STWR CALC.doc Page 4 of 4

Appendices
Cu
15
10
8
6
0
L_
N
4
m
L
U
C
2
T
:y
C
m
1
0.8
0.6
0.4
Q I
i■w�iwiw■w■�ww��w■iw
�■w■ww
' •
wwwww■ww
wwwwww
■�wwww��►;SM
ON
-Mill
5 10 20 40 60 2 3 4 6 8 12 18 24
Minutes Hours
Figure 8.03b Rainfall intensity duraiian curves —Wilmington.
20
15
10'
8
a
1 4
L
U
C 2
Qy 1
c 0.8
m 0.6
`c
Ta 0.4
t3:
0.
Qf
Duration
ww■1ww
Hatter
#rra
mm
NO
tititi1�1•
��>•>•�����
MUNI
w10101
i
,1
S 10 20 40 60 2 3 4 6 8 12 18 24
Minutes Hours
Duration
Figure 8.03c Rainfall intensity duration curves —Hatteras.
0
8.035

FIGURE5 I8I
FIGURE 4
FLOW FOR CIRCULAR PIPE FLOWING FULL
BASED ON MANNING'S EQUATION n=0.012
5000
4000
3000
2000
1000
800
600
500
400
300
200
p 10C
w 8C
,r 6C
a 5C
t- 4C
w
w 3C
U-
U_
m 2C
U
Z_
1C
0
ti
6
5
4
R� MIS
0 WRAP zi 0 K", PAP A
01 •02 .03'.04.05 .1 .2 .3 .4.5.6 .8 1. 2 3 4 5 6 810
SLOPE OF PIPE IN FEET PER 100 FEET
2
I

SUPERIOR CENTER
Erosion Control Plan
Outlet Protection Design
18" 0 Pipe Outlets
Use attached Nomographs to determine Rip Rap size and Rip Rap apron
configuration for 18" 0 RCP discharging to detention pond and from detention
pond to U.S. 421 R/W ditch. (9.2 CFS)
Design Criteria:
1. Flow = 9 CFS; 18" 0 outlet pipe
2. Assume minimum tailwater conditions; no defined channel.
Pipe Diameter = Do = 1.5'
Apron Length = La = 10' (from Nomograph)
Upstream Apron Width = W„ = 3 x Do = 3 x 1.5' = 4.5'
Downstream Apron Width = Do + .4La = 1.5' + 10' = 11.5' Min.
Median Stone Size = d5o = 0.4' Min. (from Nomograph)
(See attached Rip Rap Blanket Configuration - Plan View)
Select "Class B" Stone (minimum) 5" - 15"
Apron Thickness = 1.5 x dmax = 1.9'
SUPERIOR CTR.18 PIPE OUTI.Er.doc Page 1 of 1

Water Conveyance and Energy Dissipation 7.57
ment. However, to simplify our calculations, we will assume that both i and A remain
constant. Therefore, the pestdevelopment runoff is
0.6 ( 0.6 )
0.3 (20 ft'Isec) v 40 ft'/sec 0.3 (0.57 ma/sec) s 1.14 m3/sec
This flow will exceed the natural capacity of the stream. It may erode the streambank
and cause flooding problems.
STD 3. Determine how to accommodate the postdevelopment flow in a nonerosive man-
ner. There are several ways we could handle the increased flow. We could further divide
the subdivision so that approximately one-half drains into the stream and one-half
e, :rl.s
1.
Z 3
r
� 1
f 1 ,
r
!r �115 �
� 1
r �
� l
� � 1
i
W (max. TWI
W -(min. TW)
Fig. 7.47 Riprap blanket configuration for outlet protec-
tion; see the reference for design details. (2)
1 0 r/ 69 R-GP
0

L. 'i = 10 ,
7.54 Erosion and Sediment Control Handbook
.3 0,
2 Wd - 09' L.. 30
Outlet 1 I tO 90
pipe toy
diameter0, croEaP 25 r4•K 80
'CL' of apto 70
20 a
60
15 - —
• 1.4
o Q'
can 1.3
Nmm u v 4 1.2
1.0 E
3
0.9
E ors u a 5 10.8
0� 0 d i I' "—�—i yti'a" a 2,N 106
70.5
a
M1 10.4
j2 d Qc to l u7�� 1 0.3
N m
� � � I �0.2
1 .I
0
3 5 10 20 s0 100 200 500 1000
�.2 C♦L5 Oischarge, ft3/sec
0.1 0.2 0.3 0.4 0.6 0.8 1 2 3 4 5 5 7 8 10 15 2025
Discharge, m3lsec
Fig. 7.45 Design of riprap outlet protection from a round pipe flowing full; minimum
tailwater conditions. (6, 14)
to find the riprap size and apron length. The apron width at the pipe end should
be 3 times the pipe diameter. Where there is a well-defined channel immediately
downstream from the apron, the width of the downstream end of the apron
should be equal to the width of the channel. Where there is no well-defined chan-
nel immediately downstream from the apron, minimum tailwater conditions
apply and the width of the downstream end of the apron should be equal to the
pipe diameter plus the length of the apron.
EitiMPLE 7.4 Biprap Outlet Protection Design Calculation for Minimum
Tailwater Condition
Given: A flow of 6 ft3/sec (0.17 m'/sec) discharges from a 12-in (30-cm) pipe onto a 2
percent grassy slope with no defined channel. _
Find The required length, width, and median stone size d,a for a riprap apron.
d ,�, = & q-=`