HomeMy WebLinkAbout20080525 Ver 1_Stormwater Approval_20090507A
NCDENR
North Carolina Department of Environment and
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins
Governor Director
May 7, 2009
Jaganathan Gnanasekaran, Owner
561 Ambergate Place NW
Concord, NC 28027
OP Natural Resources
Dee Freeman
Secretary
Subject: State Stormwater Management Permit No. SW8 090106
Jaganathan Gnanasekaran Property
High Density Commercial Wet Detention Pond Project
Pender County
Dear Mr. Gnanasekaran:
The Wilmington Regional Office received a complete Stormwater Management Permit
Application for the Jaganathan Gnanasekaran Property on May 1, 2009. Staff review of
the plans and specifications has determined that the project, as proposed, will comply
with the Stormwater Regulations set forth in Title 15A NCAC 2H.1000 and Session Law
2008-211. We are forwarding Permit No. SW8 090106 dated May 7, 2009 for the
construction of the subject project.
This permit shall be effective from the date of issuance until May 7, 2019, and shall be
subject to the conditions and limitations as specified therein. Please pay special
attention to the Operation and Maintenance requirements in this permit. Failure to
establish an adequate system for operation and maintenance of the stormwater
management system will result in future compliance problems.
If any parts, requirements, or limitations contained in this permit are unacceptable, you
have the right to request an adjudicatory hearing upon written request within thirty (30)
days following receipt of this permit. This request must be in the form of a written
petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed
with the Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-
7447. Unless such demands are made this permit shall be final and binding.
If you have any questions, or need additional information concerning this matter, please
contact Steve Pusey or me at (910) 796-7215.
Sinc rely,
eorgette Scott
Stormwater Supervisor
Division of Water Quality
GDS/ sgp: S:\WQS\STORMWATER\PERMIT\090106.may09
cc: Brad Sedgwick, PE - JBS Consulting, PA
Pender County Building Inspections
Steve Pusey
Wilmington Regional Office
Central Files
Wilmington Regional Office
127 Cardinal Drive Extension, Wilmington, North Carolina 28405 ODe
Phone: 910-796-72151 FAX: 910-350-20041 Customer Service: 1-877.623-6748 NorthCarolina
Internet: www.ncwaterquality.org ?atuNn???
An Equal Opportunity 1 Affirmative Action Employer `N
State Stormwater Management Systems
Permit No. SW8 090106
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
STATE STORMWATER MANAGEMENT PERMIT
HIGH DENSITY COMMERCIAL DEVELOPMENT
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of
North Carolina as amended, and other applicable Laws, Rules, and Regulations
PERMISSION IS HEREBY GRANTED TO
Jaganathan Gnanasekaran
Jaganathan Gnanasekaran Property
Hwy 17, Hampstead, Pender County
FOR THE
construction, operation and maintenance of one wet detention pond in compliance with
the provisions of 15A NCAC 2H .1000 and Session Law 2008-211 (hereafter
collectively referred to as the "stormwater rules') the approved stormwater
management plans and specifications and other supporting data as attached and on file
with and approved by the Division of Water Quality and considered a part of this permit.
This permit shall be effective from the date of issuance until May 7, 2019, and shall be
subject to the following specified conditions and limitations:
1. DESIGN STANDARDS
1. This permit is effective only with respect to the nature and volume of stormwater
described in the application and other supporting data.
2. This stormwater system has been approved for the management of stormwater
runoff as described in Section 1.8 on page 3 of this permit. The stormwater
control has been designed to handle the runoff from 31,913 square feet of
impervious area.
3. A 50' wide vegetative buffer must be provided adjacent impounded structures,
streams, rivers and tidal waters.
4. This wet detention pond must be operated with a 30' vegetated filter strip
designed to pass the 10 year storm in a diffuse, non-erosive manner.
5. The tract will be limited to the amount of built-upon area indicated on page 3 of
this permit, and per approved plans.
6. All stormwater collection and treatment systems must be located in either
dedicated common areas or recorded easements. The final plats for the project
will be recorded showing all such required easements, in accordance with the
approved plans.
Page 2 of 7
State Stormwater Management Systems
Permit No. SW8 090106
5. Decorative spray fountains will not be allowed in the stormwater treatment
system.
6. The facilities shall be constructed as shown on the approved plans. This permit
shall become void unless the facilities are constructed in accordance with the
conditions of this permit, the approved plans and specifications, and other
supporting data.
7. Upon completion of construction, prior to issuance of a Certificate of Occupancy,
and prior to operation of this permitted facility, a certification must be received
from an appropriate designer for the system installed certifying that the permitted
facility has been installed in accordance with this permit, the approved plans and
specifications, and other supporting documentation. Any deviations from the
approved plans and specifications must be noted on the Certification. A
modification may be required for those deviations.
8. If the stormwater system was used as an Erosion Control device, it must be
restored to design condition prior to operation as a stormwater treatment device,
and prior to occupancy of the facility.
9. Access to the stormwater facilities for inspection and maintenance shall be
maintained via appropriate recorded easements at all times.
10. The permittee shall submit to the Director and shall have received approval for
revised plans, specifications, and calculations prior to construction, for any
modification to the approved plans, including, but not limited to, those listed
below:
a. Any revision to any item shown on the approved plans, including the
stormwater management measures, built-upon area, details, etc.
b. Project name change.
C. Transfer of ownership.
d. Redesign or addition to the approved amount of built-upon area or to the
drainage area.
e. Further development, subdivision, acquisition, lease or sale of any, all or
part of the project area. The project area is defined as all property owned
by the permittee, for which Sedimentation and Erosion Control Plan
approval or a CAMA Major permit was. sought.
f. Filling in, altering, or piping of any vegetative conveyance shown on the
approved plan.
11. Prior to the construction of any permitted future areas shown on the approved
plans, the permittee shall submit final site layout and grading plans to the
Division for approval.
12. A copy of the approved plans and specifications shall be maintained on file by
the Permittee at all times.
13. The Director may notify the permittee when the permitted site does not meet one
or more of the minimum requirements of the permit. Within the time frame
specified in the notice, the permittee shall submit a written time schedule to the
Director for modifying the site to meet minimum requirements. The permittee
shall provide copies of revised plans and certification in writing to the Director
that the changes have been made.
Page 4 of 7
State Stormwater Management Systems
Permit No. SW8 090106
Jaganathan Gnanasekaran Property
Stormwater Permit No. SW8 090106
Pender County
Designer's Certification
I, , as a duly registered in the
State of North Carolina, having been authorized to observe (periodically/ weekly/ full
time) the construction of the project,
(Project)
for (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.
The checklist of items on page 2 of this form is included in the Certification.
Noted deviations from approved plans and specifications:
SEAL
Signature
Registration Number
Date
Page 6 of 7
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
This form may be photocopied for use as an original
I. GENERAL INFORMATION
1. Applicants name (specify the name of the corporation, individual, etc. who owns the project):
laganathan Gnanasekaran
2. Print Owner/Signing official's name and title (person legally responsible for facility and compliance):
TaUnathan Gnanasekaran / Owner
3. Mailing Address for person listed in item 2 above:
561 Ambergate Place NW
City:Concord State:NC Zip:28027
Phone: (7'14-) Y-yd - Y-11 9 Fax: )
Email:.shekarLrn@vahoo.com
4. Project Name (subdivision, facility, or establishment name -should be consistent with project name on plans,
specifications, letters, operation and maintenance agreements, etc.):
Jaganathan Gnanasekaran Property
5. Location of Project (street address):
17 Hwy
City:Ham sp tead County:Pender Zip:28443
6. Directions to project (from nearest major intersection):
From the intersection of SR 210 and US 17, o north on US 17 site is on the left approximently 1 2 miles
7. Latitude:0340 22' 41.55" N Longitude:077141' 58.63" W of project
8. Contact person who can answer questions about the project:
Name:Brad Sedgwick, PE Telephone Number: (910 ) 619-9330
Email: bradsedgwick@hotmail.com
II. PERMIT INFORMATION:
1. Specify whether project is (check one): [DNew [JRenewal []Modification
Form SWU-101 Version 09.25.08 Page 1 of 4
L L ?. eJ t ,' State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
9. How was the off-site impervious area listed above derived?N/A
Projects in Union County: Contact the DWQ Central Office staff to check to see ifyou project is located
within a Threatened & Endangered Species watershed that may be subject to more stringent stormwater
requirements.
IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
One of the following property restrictions and protective covenants are required to be recorded for all
subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table
listing each lot number, size and the allowable built-upon area for each lot must be provided as an attachment.
Forms can be downloaded from httl2:Hh2o.enr.state.nc.us/su/bmp forms.htm - deed restrictions.
Form DRPC-1 High Density Commercial Subdivisions
Form DRPC-2 High Density Developments with Outparcels
Form DRPC-3 High Density Residential Subdivisions
Form DRPC4 Low Density Commercial Subdivisions
Form DRPC-5 Low Density Residential Subdivisions
Form DRPC-6 Low Density Residential Subdivisions with Curb Outlets
By your signature below, you certify that the recorded property restrictions and protective covenants for this
project shall include all the applicable items required in the above form, that the covenants will be binding
on all parties and persons claiming under them, that they will run with the land, that the required covenants
cannot be changed or deleted without concurrence from the NC DWQ, and that they will be recorded prior to
the sale of any lot.
V. SUPPLEMENT FORMS
The applicable state stormwater management permit supplement form(s) listed below must be submitted for each
BMP specified for this project. Contact the Stormwater Permitting Unit at (919) 807-6300 for the status and
availability of these forms. Forms can be downloaded from http://b2o.enr.state.nc.us/su/bmj2 forms.htm.
Form SW401-Low Density Low Density Supplement
Form SW401-Curb Outlet System Curb Outlet System Supplement
Form SW401-Off-Site System Off-Site System Supplement
Form SW401-Wet Detention Basin Wet Detention Basin Supplement
Form SW401-Infiltration Basin Infiltration Basin Supplement
Form SW401-Infiltration Trench Underground Infiltration Trench Supplement
Form SW401-Bioretention Cell Bioretention Cell Supplement
Form SW401-Level Spreader Level Spreader/Filter Strip/Restored Riparian Buffer Supplement
Form SW401-Wetland Constructed Wetland Supplement
Form SW401-Grassed Swale Grassed Swale Supplement
Form SW401-Sand Filter Sand Filter Supplement
Form SW401-Permeable Pavement Permeable Pavement Supplement
Form SW401-Cistern Cistern Supplement
Form SWU-101 Version 09.25.08 Page 3 of 4
Permit Number: 5'/;)S-s
(to be provided by DWQ)
Drainage Area Number:
Wet Detention Basin Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BMP elements noted in the inspection will be
corrected, repaired or replaced immediately. These deficiencies can affect the integrity
of structures, safety of the public, and the removal efficiency of the BMP.
The wet detention basin system is defined as the wet detention basin,
pretreatment including forebays and the vegetated filter if one is provided.
This system (check one):
? does ® does not incorporate a vegetated filter at the outlet.
This system (check one):
? does ® does not incorporate pretreatment other than a forebay.
Important maintenance procedures:
Immediately after the wet detention basin is established, the plants on the
vegetated shelf and perimeter of the basin should be watered twice weekly if
needed, until the plants become established (commonly six weeks).
No portion of the wet detention pond should be fertilized after the first initial
fertilization that is required to establish the plants on the vegetated shelf.
Stable groundcover should be maintained in the drainage area to reduce the
sediment load to the wet detention basin.
If the basin must be drained for an emergency or to perform maintenance, the
flushing of sediment through the emergency drain should be minimized to the
maximum extent practical.
Once a year, a dam safety expert should inspect the embankment.
After the wet detention pond is established, it should be inspected once a month and
within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a
Coastal County). Records of operation and maintenance should be kept in a known set
location and must be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element: Potential problem: How I will remediate the problem:
The entire BMP Trash debris is resent. Remove the trash/ debris.
The perimeter of the wet Areas of bare soil and/or Regrade the soil if necessary to
detention basin erosive gullies have formed. remove the gully, and then plant a
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application
rVegetation is too short or too Maintain vegetation at a height of
approximately six inches.
Form SW401-Wet Detention Basin O&M-Rev.4 Y Page 1 of 4
Permit N umber: SW g 6161"10
(to be provided by DWQ)
Drainage Area Number:
BMP element: Potential problem: How I will remediate the problem:
The embankment Shrubs have started to grow Remove shrubs immediately.
on the embankment.
Evidence of muskrat or Use traps to remove muskrats and
beaver activity is present. consult a professional to remove
beavers.
A tree has started to grow on Consult a dam safety specialist to
the embankment. remove the tree.
An annual inspection by an Make all needed repairs.
appropriate professional
shows that the embankment
needs repair. if applicable)
The outlet device Clogging has occurred. Clean out the outlet device. Dispose
of the sediment off-site.
The outlet device is damaged Repair or replace the outlet device.
The receiving water Erosion or other signs of Contact the local NC Division of
damage have occurred at the Water Quality Regional Office, or
outlet. the 401 Oversight Unit at 919-733-
1786.
The measuring device used to determine the sediment elevation shall be such
that it will give an accurate depth reading and not readily penetrate into
accumulated sediments.
When the permanent pool depth reads 6 feet in the main pond, the sediment
shall be removed.
When the permanent pool depth reads 6 feet in the forebay, the sediment shall
be removed.
BASIN DIAGRAM
(fill in the blanks)
Permanent Pool Elevation 46.5
Sediment Removal
Bottom
40-5 ]
----------
-/Volume
-ft Min.
Sediment
Storage
Pool
- - - -Sediment Removal Elevation 40.5 Volume
-- - ------?
FOREBAY
Bottom Elevation
MAIN POND
1-ft
Storage
Form SW401-Wet Detention Basin O&M-Rev.4 Page 3 of 4
&
Permit No.?? it
(to be provided by DWQ)
OF W A T?9
?®'A
^A O? 9G
r
NCDENR o
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part Ill) must be printed, filled out and submitted along with all of the required information,
1 R TION
Project name Jaganathan Gnanasekaran. Property
Contact person Brad Sedgwick, PE
Phone number (910) 619-9990
Date 12/1912008 (revised 5/1/09)
Drainage area number 1
11, DESfG.. TION
Site Characteristics
Drainage area
Impervious area, post-development
%impervious
Design rainfall depth
Storage Volume: Non•SA Waters
Minimum volume required
Volume provided
Storage Volume: SA Waters
1.5' runoff volume
Pre-development 1-yr, 24-hr runoff
Post-development 1-yr, 24-hr runoff
Minimum volume required
Volume provided
Peak Flow Calculations
Is the prelpost control of the lyr 24hr storm peak flow required?
1-yr, 24-hr rainfall depth
Rational C, pre-development
Rational C, post-development
Rainfall intensity: 1-yr, 24-hr storm
Pre-development 1-yr, 24-hr peak flow
Post-development 1-yr, 24-hr peak flow
Pre/Post 1-yr, 24-hr peak flow control
Elevations
Temporary pool elevation
Permanent pool elevation
SHWT elevation (approx. at the perm. pool elevation)
Top of 10ft vegetated shelf elevation
Bottom of 1 Oft vegetated shelf elevation
Sediment cleanout, top elevation (bottom of pond)
Sediment cleanout, bottom elevation
Sediment storage provided
Is there additional volume stored above the state-required temp. pool?
Elevation of the top of the additional volume
55,837 ft
31,913 ft
57.15 %
1.5 in
3,939 ft3
6,192 ft3
_ ft3
_ ft3
_ ft3
0 ft3
ft3
OK
OK, volume provided is equal to or in excess of volume required.
Y (Y or N)
3.4 in
0.30 (unidess)
0.75 (unitless)
0.72 in/hr OK
0.71 ft3/sec
3.62 ft3/sec
2.91 ft'/sec
48.00 fmsl
46.50 fmsl
46.00 fmsl
47.00 fmsl
46.00 fmsl
40.50 fmsl
39.50 fmsl
1.00 ft
y (Y or N)
48.0 tmsl OK
41f
E
qq,???j MAY 0 ? 2009
EtF $
Form SW401-Wet Detention Basin-Rev.5 Parts I. S II. Design Summary, Page 1 of 2
Permit No. SW ?. 0"Z6166
(to be provided by DWQ)
III. REQUIRED ITEMS CHECKLIST
Please indicate the page or plan sheet numbers where the supporting documentation can be found. M incomplete submittal package will
result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to
indicate the following design requirements have been met. If the applicant has designated an agent, the agent may initial below. It a
requirement has not been met, attach justification.
d.
9-
Pagel Plan
(itl_
C. ?
C.
9. A copy of the deed restrictions (if required).
( 1 7
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),
- Basin dimensions,
- Pretreatment system,
- High flow bypass system,
- Maintenance access,
- Proposed drainage easement and public right of way (ROW),
- Overflow device, and
- Boundaries of drainage easement.
2. Partial plan (1" = 30' or larger) and details for the wet detention basin showing:
- Outlet structure with trash rack or similar,
- Maintenance access,
- Permanent pool dimensions,
- Forebay and main pond with hardened emergency spillway,
- Basin cross-section,
- Vegetation specification for planting shelf, and
- Filter strip.
3. Section view of the wet detention basin (1" = 20' or larger) showing:
- Side slopes, 3:1 or lower,
- Pretreatment and treatment areas, and
- Inlet and outlet structures.
4. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified
on the plans prior to use as a wet detention basin.
5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay,
to verify volume provided.
6. A construction sequence that shows how the wet detention basin will be protected from sediment until the
entire drainage area is stabilized.
The supporting calculations.
A copy of the signed and notarized operation and maintenance (0&M) agreement.
10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
soil maps are not an acceptable source of soils information.
Form SW401-Wet Detention Basin-Rev.5 Part 111. Required Items Checklist, Page 1 of 1