HomeMy WebLinkAboutSW8010716_COMPLIANCE_20040712STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO.
SW_p%I �__CP
DOC TYPE
❑ CURRENT PERMIT
❑ APPROVED PLANS
❑ HISTORICAL FILE
COMPLIANCE EVALUATION INSPECTION
DOC DATE
YYYYMMDD
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�.; State of North Carolina
Doartment of Environment
and Natural Resources
Wilmington Regional Office
Division of Land Resources
Land Quality Section
Michael F. Easley, Governor
William G. Ross Jr., Secretary
July 12, 2004
NOTICE OF VIOLATIONS OF THE
SEDIMENTATION POLLUTION CONTROL ACT
CERTIFIED MAIL 7003 2260 0003 8606 3996
RETURN RECEIPT REQUESTED
Cumberland Management Group of NC, Inc.
Catherine L. Stephenson
2237 Acacia Drive
Wilmington, NC 28403
Dear Ms. Stephenson/Mr. Davis:
NCDENR
Eww o*w Pff ma Nl *A_ Resc"Cra
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CERTIFIED MAIL. 7003 2260 0003 8606 4009
RETURN RECEIPT REQUESTED
Johnnie Davis
5018 Randall Pkwy. # 3
Wilmington, NC 28403-2829
Project Name: Village on Eighteen @ Coastal Carolina Country Club
Project No: PE-02016
Pender County
On July 8, 2004, personnel of this office inspected a project located SR 1510 in Pender County, North Carolina.
This inspection was performed to determine compliance with the North Carolina Sedimentation Pollution Control Act of
1973. The inspection revealed a land -disturbing activity of approximately 10.8 acres being conducted.
It is our understanding that you and/or your firm are responsible for this land -disturbing activity. The purpose
of this letter is to inform you that this activity was found to be in violation of the Act, NCGS 113A-50 to 66, and Title 15A,
North Carolina Administrative Code, Chapter 4. If you feel that you are not responsible for the following violations, please
notify this office immediately.
The violations that were found are:
Failureto maintain on graded slopes and fills an anglewhich can be retained by vegetative cover or
other adequate erosion control devices or structures. NCGS 113A-57(2).
Gullies have formed on Swale slopes resulting in slopes that have angles too steep to
establish adequate groundcover.
Failure within 15 working days of 30 calendar days (whichever period is shorter) of completion of any
phase of grading to plant or otherwise provide exposed, graded slopes or fills with ground cover,
devices, or structures sufficient to restrain erosion. G.S. 113A-57(2).
Groundcover sufficient to restrain erosion has not been established on various swale slopes.
To correct these violations, you must:
1. Repair and reshape excessively steep or eroded slopes.
2. Provide groundcover sufficient to restrain erosion on eroded slopes.
Please note that merely planting grass seed does not satisfy the requirements of "vegetative cover« or of "ground
cover sufficient to restrain erosion." These requirements are not satisfied until a standing cover of grass or other ground
cover is established which is, in fact, sufficient to restrain accelerated or man-made erosion.
127 Cardinal Drive Extension, Wilmington, N.C. 28405-3845 • Telephone 910-395-3900 9 Fax 910-350-2004
An Equal Opportunity Affirmative Action Employer
\■
Ms. Stephenson/Mr. Davis
July 12, 2004
Page Two
The initial one day civil penalty could be an assessment of up to $5,000.00. A time period for compliance is
not requiredforthis initial one daycivil penalty pursuantto NCGS 113A-61.1(c) and NCGS 113A-64(a)(1). An initial
one day civil penalty is being considered for this project.
If the violations described in this Notice are not corrected within 20 days following your receipt of this
Notice, the Division of Land Resources may take additional appropriate legal action against you pursuant to NCGS
1 13A-64. That action could be the assessment of additional civil penalties and may result in the initiation of other
remedies as prescribed bythe Act. If additional civil penalties are assessed for the violations, the amount maybe up
to $5,000.00 per day for each day of the violation pursuant to NCGS 133A-Ka)(1). If all violations are corrected within
the time period specified for compliance, additional civil penalties or legal remedies will not be pursued.
Any new land -disturbing activity associated with this project should not begin until the area presently
disturbed is brought into compliance with the Act. When correctve actions are complete, you should notify this office
so that the work can be inspected. You should not assume thatthe site is in compliance with the Act until we have
so notified you. In addition, once compliance has been achieved, all installed measures mustbe satisfactorily
maintained until development is complete and the site is fully stabilized to avoid further violations of the Act.
We solicit your cooperation, and would like to avoid taking further enforcement action. At the same time, it
is your responsibility to understand and comply with the requirements of the Act. Copies of the relevant statute and
administrative rules maybe examined at this office or will be sent to you upon request. Should you have questions
concerning this Notice or the requirements of the Act, please contact either Trentt James or meat your earliest
convenience.
Please do not hesitate to contact me regarding any questions you might have about this matter.
Sincerely,
Daniel Sams, P.E., M.E.
Regional Engineer
DES/TJ/asb ,
cc: Sedimentation Specialist
WiRO-LQS
r-DWQ Supervisor-WiRO
Enclosure: Inspection Report
h _,
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A
Case #
NORTH CAROLINA DEPARTMENT OF ENT17RONMENTAND NATURAL RESOURCES
LAND QUAL17YSECTION..-127 Cardinal Drive, Ext., Wilmington, NC28405-3845 (910) 395-3900 r_
County U+-� 0 C-nrt Pro),ect: t_ sue;; a �- �1�1 River Basin CA'- O�
Person Financially Responsible: �S_ �/ Project #
Address:
1. Project Location ---5, P,icctures: NA
Yes ❑
2. Weather and Soil Conditions �s 9,
3
3. Is site currently under notice of violation? Yes ❑ No 15k'
4. Is the site in compliance with the S.P.C.A. and the rules?
Yes ❑
5. Violations:
❑ a. No approved plan, G.S.113A-57(4) and 15A NCAC 4B.0107(c)
❑ g.
❑ b. Failure to follow approved plan, C.S. 113A-61.1
ah.
❑ c. Failure to submit revised plan, G.S. 113A-54.1(b) and
15A NCAC 4B.0118(a)
❑ d. Failure to provide adequate groundcover, C.S. 113A-57(3) and
❑ j.
15A NCAC 4B.0107(b) or 15A NCAC 413.0124(e)
❑ e. Insufficient measures to retain sediment on site, G.S. 113A-57(3)
❑ k.
❑ f. Failure to take all reasonable measures, 15A NCAC 4B.0105
6. NPDES Permit Violation? Yes K No ❑ Describe
Prints ❑ Slides ❑ Digital ❑ Video ❑
No'W If no, check violations below:
Inadequate buffer zone, G.S. 113A-57(1)
Graded slopes and fills too steep, G.S. 113A-57(2)
or 15A NCAC 4B.0124(d)
Unprotected exposed slopes, G.S. 113A-57(2)
Failure to maintain erosion control measures,
15A NCAC 413.0113
Other (describe)
7. Has sedimentation damage occurred since last inspection% Yes ❑ If yes, where' (check all that apply): No
Lake/natural watercourse on the tract ❑ Lake/natural watercourse off the tract ❑ Other property 1_
Description:
Degree of damage: Slight ❑ Moderate ❑ Severe ❑
S. Contact made with (Name) Cki3 - kk'-ehLc e" .. l 7 Title
to Person Financially Responsible Date given/sent Inspection Report given ❑ or sent _
9. Corrective actions needed:
L/�'ccc-cSPES _
10. Comments: _ CP ^C i*/L` S H-19 ✓--t` /tit +a06 T7-) -A1L1.��
til t'f3 es.-'3 7^z_PLI /�'/G` eAJ iD eras, e✓ 4s_1 �_� !3� _
Report by: yr+ lk TF _ �r_ "�`` S Others present
Date of Inspection: _7G '7 Time arriving at site: Time leaving site: 2
cc:
DETENTION POND ANALYSIS FILE NAME: S:1WQSIPOND1010716.WK1
PROJECT #: SW8 010716 REVIEWER: L. Lewis
PROJECT NAME: Village on Eighteen @ DATE: 17-Sep-2001
Coastal Carolina Country Club
Receiving Stream: UT Burgaw Creek Class: C SW
Drainage Basin: Cape Fear Index No. 18-74-39
Site Area 10.25 acres
Drainage Area 46490:00', square feet Area in Acre 10.25
IMPERVIOUS AREAS
Rational C
32 lots @4350 sf 139200.00 square feet 1.00
Streets 61456.00 square feet 1.00
square feet
square feet
square feet
square feet
TOTAL
N0Q656.0Q square feet Rational Cc= 0.56
SURFACE AREA CALCULATION
% IMPERVIOUS
44.94%
SAIDA Ratio
3.90%
Des. Depth
4
Req. SA
17392 sf
TSS:
90
Prov. SA
20096sf
VOLUME CALCULATION * place a "1" in the box if Rational is used
Rational ?*
1
Des. Storm
1 00 inches
Rv=
0.45
Bottom
16 msl
Perm. Pool20.Q0'
msl
Design Pool
21 msl
Design SA
22400 sf
Req. Volume
20819! cf
Prov. Volume
21248' cf
ORIFICE CALCULATION
FOREBAY Al
PeP$el Volume=
Req. Forebay Volume=
Provided Volume=
Percent=
SA @ _
Elevation=
COMMENTS
Surface Area , Volume and Orifice are within Design Guidelines
.46960 (iVO 8
-9392 13 (v 42
13713.00
2� ZO.1
oic- 2� 25
1
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11
1
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VILLAGE ON EIGHTEEN AT
COASTAL CAROLINA COUNTRY CLUB
PENDER COUNVY
STORMWATER MANAGEMENT CALCULATIONS
July 2001
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Prepared By:
JOSEPH S. HILL, JR. and ASSOCIATES
CONSULTING ENGINEERS and PLANNERS
1602 Harbour drive
Wilmington, North Carolina 28401
(910)799-1544
1
1
1
1
1
1
1
1
1
1
1
1
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1
VOE.STWi'R CALC.doc
TABLE OF CONTENTS
1. Detention Pond Calculations
2. Forebay Calculations
4
RECEIVED
SEP 2 5 2001
VILLAGE ON EIGHTEEN AT
COASTAL CAROLINA COUNTRY CLUB
Dwe
pROJ # SW-8 0104 (O 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 -
Houses, driveways, (4,350 SF/Lot x 32 Lots) = 139,200 SF
Streets = 61,456 SF
Total Impervious Surfaces = 200,656 SF (4.6064 AC.)
Total Area = 10.25 Ac. = 446,490 SF
Total Pervious Area = 245,834 SF
1" Runoff from Impervious Surfaces = 0.0834' x 200,656 SF = 16,735 CF
1" Runoff from Pervious Surfaces = 0.2 x 0.0834' x 245,834 SF = 4,100 CF
Total runoff to be stored in pond = 20,835 CF
156,263 Gal.
Detention Pond Calculations
Pond Surface area @ Temporary Pool Elev. Of 21.0' = 22,400 SF
Pond Surface area @ Permanent Pool Elev. Of 20.0' = 20,096 SF
Average Pond Surface Area = 21,248 SF
Pond Storage Volume = 21,248 SF x 1.0' Depth = 21,248 CF
20,098 CF + 21,248 CF = 0.95 Pond Storage Depth Required (use 1.0')
s cJ�G
Total Watershed Area = 10.25 Ac. = 446,490 SF
Impervious % _ .200 656 SF - 446,490 SF = 45%IV
��' + 2• q"
Pond Depth - 4.0''g' r
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VOE.STWTR CALC.doc `�F/a�;'.:••.����
l
VILLAGE ON EIGHTEEN AT
COASTAL CAROLINA COUNTRY CLUB
iStormwater 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 J
Impervious Surfaces -
1`
Houses, driveways, (4,350 SF/Lot x 32 Lots) = 139,200 SF
Streets = 61,456 SF
Total Impervious Surfaces = 200,656 SF (4.6064 AC.)
Total Area = 10.25 Ac. = 446,490 SF
1 Total Pervious Area = 245,834 SF
1" Runoff from Impervious Surfaces = 0.0834' x 200,656 SF = 16,735 CF
1" Runoff from Pervious Surfaces = 0.2 x 0.0834' x 245,834 SF = 4,100 CF
Total runoff to be stored in pond = 20,835 CF
= 156,263 Gal.
Detention Pond Calculations re
Pond Surface area @ Temporary Pool Elev. 0 20.0 = 221400 SF
Pond Surface area @ Permanent Pool Elev. Of 21.0' = 20,096 SF
1 Average Pond Surface Area = 211248 SF
Pond Storage Volume = 21,248 SF x 1.0' Depth = 21,248 CF
20,098 CF -- 21,248 CF = 0.95 Pond Storage Depth Required (use 1.0')
1 Total Watershed Area = 10.25 Ac. = 446,490 SF
Impervious % = 200,656 SF = 446,490 SF = 45%
' Pond Depth = 4.0'
VOE.STWTR CALC.doc
' Village on Eighteen at Coastal Carolina Country Club
Stormwater Detention Pond Calculations
1 Page 2
1 SA/DA % required for 90% solids removal @ 4.0' Depth (see chart) = 3.9%
3.9% x 10.25 AC. = 0.40 AC. --= 17,424 SF
Pond surface area Permanent Pool Elev. Of 20.0' = 20,096 SF
' Pond is therefore adequate for 90% TSS removal.
' Orifice DiSc',argt: Rate oCallcullatiorms
Use 2" diameter orifice for outlet
' Calculate average discharge rate and time to lower orifice head from 1.0' to 0.9':
0.1' pond height x 21,248 SF average pond area x 7.5 ga/W
' = 15,936 Gallons Storage
Average head on orifice from 1.0' to 0.9' = 0.95'
1
'
Average discharge rate @ 0.95' head:
Q(GPM) = (449)c A-/2gh
'
Q(GPM) = Volume discharge 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)(0.0218)-/(2)(32.2)(0.95)
Q = 45.9 GPM
Time required t l v q a lower on s pond 0.1 @ 0 95 average head.
'
T = 15,936 Gal. = 45.9 GPM = 347
45.9 GPM vs 347 minutes plotted on curve (see discharge curve).
1
Ivoe.STWTR cALc.aoc
0
1
I
Village on Eighteen at Coastal Carolina Country Club
Stormwater Detention Pond Calculations
Page 3
Discharge rate and time to lower head from 0.9' to 0.8':
Q = 43.5 GPM
T = 15,936 Gal.:- 43.5 GPM = 366 minutes
43.5 GPM vs 713 minutes plotted on curve.
Discharge rate and time to lower head from 0.8' to 0.7':
Q=40.8GPM
T = 15,936 Gal. ; 40.8 GPM = 391 minutes
40.R GPI vs i,lV I minutes plotted on curve.
Discharge rate and time to lower head from 0.7' to 0.6':
' Q = 38.0 GPM
T = 15,936 Gal. = 38.0 GPM = 419 minutes
38.0 GPM vs 1,523 minutes plotted on curve.
1
n
Discharge rate and time to lower head from 0.6' to 0.5':
Q = 35.0 GPM
T = 15,936 Gal. = 35.0 GPM = 455 minutes
35.0 GPM vs 1,978 minutes plotted on curve.
Discharge rate and time to lower head from 0.5' to 0.4':
Q = 31.6 GPM
T = 15,936 Gal. = 31.6 GPM = 504 minutes
31.6 GPM vs 2,482 minutes plotted on curve.
Discharge rate and time to lower head from 0.4' to 0.3':
Q = 27.9 GPM
T = 15,936 Gal. = 27.9 GPM = 571 minutes
571 GPM vs 3,053 minutes plotted on curve.
Discharge rate and time to lower head from 0.3' to 0.2:
Q = 23.5 GPM
T = 15,936 Gal. 23.5 GPM = 678 minutes
23.5 GPM vs 3,731 minutes plotted on curve.
Discharge rate and time to lower head from 0.2' to 0.1':
Q = 18.3 GPM
T = 15,936 Gal. = 18.3 GPM = 871 minutes
18.3 GPM vs 4,602 minutes plotted on curve.
.t:
VOE.STWTR CALC.doc
' Village on Eighteen at Coastal Carolina Country Club
Stormwater Detention Pond Calculations
' Page 4
Discharge rate and time to lower head from 0.1' to 0.0':
Q = 10.5 GPM
T = 15,936 Gal. = 10.5 GPM = 1,518 minutes
10.5 GPM vs 6,120 minutes plotted on curve.
The outlet structure will discharge the total calculated runoff volume of 156,263
gallons in approximately 3.7 days (see Orifice Discharge Curve).
L�
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' VOE.MM CALC.doc
ll
I
'
SA/DA
- 85%
TSS REMOVAL
WITH 30' VEGETATIVE FILTER
IMPER.%
3.OFT
3.5FT
4.OFT 4.5FT
SOFT
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%
50%
3.4
4.2
3.0
3.7
2.6
3.3
2.4
3.0
2.1
2.7
1.9
2.4
1.6
2.1
1.4
1.8
1.1
1.5
1.O
1.3
60%
5.0
4.5
3.8
3.5
3.2
2.9
2.6
2.3
2.0
1.6
700
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.A
3.8
3.2
2.6
SA/DA
- >
90% TSS REMOVAL
FOR WET
DETENTION
WITHOUT
VEGETATIVE
FILTER
IMPER A
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
'
20v
2.4
2.0
1.8
1.7
1.5
1.4
1.2
1.0
.9
.6
300
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.
3.1
2.8
2.5
2.1
1.8
1.4
1.1
50%
5.6
5.0
4.
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
700
8.1
7.0
6.0
5.5
5.0
4.5
3.9
3.4
2.9
2.3
'
800
900
9.4
10.7
8.0
9.0
7.0
7.9
6.4
7.2
5.7
6.5
5.2
5.9
4.6
5.2
4.0
4.6
3.4
3.9
2.8
3.3
100%
12.0
10.0
8.8
8.1
7.3
6.6
5.8
5.1
4.3
3.6
' z4-517o L PIP E 11 !? J
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Village on Eighteen at Coastal Carolina Country Club
Stormwater Detention Pond Calculations
Page 7
Forebay Calculations
Provide approximately 20% of Total Pond volume including area of forebay
construction and temporary pool volume:
Permanent Pool Volume:
1'Clm2nen� 1'UUI rilCu e— i'eW. 20.0 � �- �U,..w .1+
Pond Area @ Elev. 16.0' — 3,384 SF
Pond Average Area = 11,740 SF
111740 SF x 4.0' depth = 46,960 CF Permanent Pool Volume
Temporary Pool Volume = 21,248 CF
Total Pond Volume = 68,208 CF
Forebay Volume:
Forebay Area @ Elev. 20.2' = 4,875 SF
Forebay Area @ Elev. 16.0' = 1,656 SF
Forebay Average Area = 3,265 SF
3,265 SF x 4.2' Depth 13,713 CF Forebay Volume
13,713 CF = 68,208 CF = 20.1%
Forebay = 20.1% of Permanent Pond Volume
VOE.5TW1"R CALC.doc
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