SW7111105_Modification_20120822

�F�A
�.i_
NCDENR
North Carolina Department of Environment and Natural Resources
Beverly Eaves Perdue
Governor
Mr. Eric T. Weatherly,
County of Currituck
153 Courthouse Road,
Currituck, NC 27929
Dear Mr. Weatherly:
Division of Water Quality
Charles Wakild, PE Dee Freeman
Director Secretary
August 22, 2012
PE, County Engineer
Suite 302
Subject: Stormwater Permit No. SW7111105 Modification
Currituck Community Park & Regional Aviation
and Technical Training Center
Overall Low Density Commercial Development
with Areas of High Density
Currituck County
The Washington Regional Office received a complete Stormwater Management Permit
Application for the modification of Currituck Community Park and Regional Aviation and Technical
Training Center on August 16, 2012. Staff review of the plans and specifications has determined that
the project, as proposed, will comply with the Stormwater Regulations set forth in Session Law 2008-
211 and Title 15A NCAC 2H.1000. We are forwarding Permit No. SW7111105MOD dated August 22,
2012, for the continued construction of the subject pro1'ect. By issuance of this permit, permit
SW7111105 which was issued on November 29, 2011 is hereby rescinded.
This permit shall be effective from the date of issuance until November 29, 2021, 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 ne add'tional information concerning this matter, please
contact Scott Vinson, or me at (252) 946�648,,A.
V Regioha1 Supervisor
Surface Water Protection Section
AH/ sv: K:\WQS\STORMWATER\PERMIT\SW7111105MOD
cc: Sean Robey, PE — Hyman & Robey, PC
Mark Breen, PE — Site Solutions, PA
Washington Regional Office
North Carolina Division of Water Quality Internet: www.newaterguality.org
943 Washington Square Mall Phone: [phone] One
Washington, NC 27889 FAX [phone] NorthCarolina
An Equal Opportunity/AffrmativeAction Employer— 50% Recycled/10% Post Consumer Paper )Vaturally

State Stormwater Management Systems
Permit No. SW7111105MOD
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
STATE STORMWATER MANAGEMENT PERMIT
OVERALL LOW DENSITY COMMERCIAL DEVELOPMENT
WITH AREAS OF HIGH DENSITY
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
County of Currituck
Currituck Community Park and Regional Aviation and Technical Training Center
off NC Hwy 158, between Airport Rd. & Aviation Parkway, Barco, Currituck County
FOR THE
construction, operation and maintenance of an overall low density commercial
development with a wet detention pond as the treatment system for Drainage Area
No.2 and two constructed wetland systems for Drainage Areas No.4 & No.5, all in
compliance with the provisions of Session Law 2008-211 and 15A NCAC 2H .1000
(hereafter referred to as the "stormwater rules') and 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 November 29, 2021, and
shall be subject to the following specified conditions and limitations:
I. 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. The built -upon area percentage for this 83.94 acre project is currently approved
for 13.9% and must be maintained at 24% or lower per the requirements of
Session Law 2008-211 and 15A NCAC 2H .1000. This project is permitted for a
maximum of 508,017 square feet of built upon area consisting of 237,267 square
feet for the Low Density areas of the project and 270,750 square feet for the
three High Density areas within this project.
3. The stormwater systems proposed to treat the runoff generated by the
designated high density areas have been approved for the management of
stormwater runoff as described in Section 1.7 & 1.8 on page 3 of this permit.
Page 2 of 9

State Stormwater Management Systems
Permit No. SW7111105MOD
4. 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.
5. The runoff from all built -upon area within the high density portion of the permitted
drainage area of this project must be directed into the permitted stormwater
control system. Within the low density portions of the permitted project, the only
runoff conveyance systems allowed will be vegetated conveyances such as
swales with minimum side slopes of 3:1 (H:V) as defined in the stormwater rules
and as shown on the approved plans. The built -upon area for the future
development is limited to 100,000 square feet within the low density drainage
area #1 and 10,000 square feet within the high density drainage area #2 as set
within the approved plans and application. Plans for any future built -upon area
not currently shown on the approved plans must be submitted and approved by
the Division prior to the start of construction.
6. The built -upon areas associated with this project shall be located at least 50 feet
landward of all perennial and intermittent surface waters.
7. The following design criteria have been provided in the wet detention pond and
must be maintained at design condition:
Drainage Area No.2
a. Drainage Area, acres: 5 ac 4, 55s
b. Total Impervious Surfaces, ft2: 6.143,555
C. Design Storm, inches: 1.50
d. Pond Depth, feet: 7.50 (4.0'average)
e. TSS removal efficiency: 90%
f. Permanent Pool Elevation, FMSl2: 7.00
gg Permanent Pool Surface Areq, ft : 12,800
h. Permitted Storage Volume, ft : 23,921 (at temporary pool elev)
i. Temporary Storage Elevation, FMSL: 8.50
j. Predevelopment 1 year 24 hour: 1.45 cfs
k. Post development 1 year 24 hour: 0.12 cfs w/control
I. Controlling Orifice: 2.50" O pipe
M. Permitted Forebay Volume, ft3: 7,752
n. Fountain Horsepower, HP 1/6 Hp
o. Receiving Stream/River Basin: UT to North River / Pasquotank
P. Stream Index Number: 30 — 2
q. Classification of Water Body: "SC"
8. The following design criteria have been provided in the two constructed wetlands
and must be maintained at design condition:
DA #4 DA#5
a. Drainage Area, ft2: 64,033 206,039
b. Total Impervious Surfaces, ft2: 44,867 82,328
C. Design Storm, inches: 1.50 1.50
d. Permanent Pool (PP)Elevation, FMS _ 5.50 6.00
e. Shallow Water (PP) Surface Area, ft 2,383 4,272
f. Temporary Pool TP) Elevation, F.KSL: 6.75 6.92
gg Shallow Land (T ) Surface Area, ft : 2,399 4,300
h. Deep Pool (incl Forebay) Suvace Area, ft2: 1,241 2,223
i. Required Storage Volume, ft • 5,433 10,559
1 Permitted Storage Volume, ft3: 5,433 10,559
k. Controlling Orifice: 1.50"0 1.50"0 pipes
I. Receiving Stream/River Basin: UT to North River / Pasquotank
M. Stream Index Number: 30-2
n. Classification of Water Body: "SC"
Page 3 of 9

State Stormwater Management Systems
Permit No. SW7111105MOD
II. SCHEDULE OF COMPLIANCE
The stormwater management system shall be constructed in its entirety,
vegetated and operational for its intended use prior to the construction of any
built -upon surface.
2. During construction, erosion shall be kept to a minimum and any eroded areas of
the system will be repaired immediately.
3. The permittee shall at all time provide the operation and maintenance necessary
to assure the permitted stormwater system functions at optimum efficiency. The
approved Operation and Maintenance Plan must be followed in its entirety and
maintenance must occur at the scheduled intervals including, but not limited to:
a. Semiannual scheduled inspections (every 6 months).
b. Sediment removal.
C. Mowin.9 and re -vegetation of slopes and the vegetated filter strip.
d. Immediate repair of eroded areas.
e. Maintenance of all slopes in accordance with approved plans and
specifications.
f. Debris removal and unclogging of outlet structure, orifice device, level
spreader, filter strip, catch basins and piping.
g. Access to the outlet structure must be available at all times.
4. Records of maintenance activities must be kept for each permitted BMP. The
records will indicate the date, activity, name of person performing the work and
what actions were taken.
5. Access to the stormwater facilities shall be maintained via appropriate
easements at all times.
6. Decorative spray fountains will be allowed only in the wet detention basin
system, sub'ect to the following criteria:
a. The fountain must draw its water from less than 2' below the permanent
pool surface.
b. Separated units, where the nozzle, pump and intake are connected by
tubing, may be used only if they draw water from the surface in the
deepest part of the pond.
c. The falling water from the fountain must be centered in the pond, away
from the shoreline.
d. The maximum horsepower for a fountain in this pond is 1/6 horsepower.
7. 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.
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.
9. 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.
Page 4 of 9

State Stormwater Management Systems
Permit No. SW7111105MOD
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 subdivision, acquisition, lease or sale of 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. 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.
12. The permittee shall submit final site layout and grading plans for any permitted
future areas shown on the approved plans and receive approval prior to the start
of construction.
13. A copy of the approved plans and specifications shall be maintained on file by
the Permittee at all times.
14. 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.
15. Prior to transfer of the permit, the stormwater facilities will be inspected by DWQ
personnel. The facility must be in compliance with all permit conditions. Any
items not in compliance must be repaired or replaced to design condition prior to
the transfer. Records of maintenance activities performed to date will be
required.
16. Prior to the subdivision and/or sale of this project, in whole or in part, the
following deed restrictions must be recorded with the Office of the Register of
Deeds:
a. The following covenants are intended to ensure ongoing compliance with
State Stormwater Management Permit Number SW7111105, as issued by
the Division of Water Quality under NCAC 2H.1000.
b. The State of North Carolina is made a beneficiary of these covenants to the
extent necessary to maintain compliance with the Stormwater Management
Permit.
C. These covenants are to run with the land and be binding on all persons and
parties claiming under them.
d. The covenants pertaining to stormwater may not be altered or rescinded
without the express written consent of the State of North Carolina, Division of
Water Quality.
e. Alteration of the drainage as shown on the approved plans may not take
place without the concurrence of the Division of Water Quality.
Page 5 of 9

State Stormwater Management Systems
Permit No. SW7111105MOD
f. This project is permitted for a maximum of 508,017 square feet of built -upon
area. Construction of additional built -upon area in excess of this amount will
require a permit modification.
g. This project may riot be sold or subdivided, in whole or in part, without first
receiving a permit modification from the Division.
h. Construction of additional impervious areas such that low -density
requirements are no longer met will require a permit modification prior to
construction. An engineered system will be required to collect and treat the
runoff from all built -upon area associated with the project, including that area
permitted under the low density option.
i. Filling in or piping of any vegetative conveyances (ditches, swales, etc.)
associated with this development, except for average driveway crossings, is
strictly prohibited by any persons.
j. The built -upon areas shall be located a minimum of 50 feet landward of all
perennial and intermittent surface waters.
17. A copy of the recorded deed restrictions must be submitted to the Division within
30 days of the date of recording the plat, and prior to selling lots. The recorded
copy must contain all of the statements above, the signature of the Permittee,
the deed book number and page, and the stamp/signature of the Register of
Deeds.
III. GENERAL CONDITIONS
This permit is not transferable except after notice to and approval by the Director.
In the event of a change of ownership, or a name change, the permittee must
submit a completed Name/Ownership Change form, to the Division of Water
Quality, signed by both parties, and accompanied by supporting documentation
as listed on page 2 of the form. The project must be in good standing with the
Division. The approval of this request will be considered on its merits and may or
may not be approved.
2. The permittee is responsible for compliance with all permit conditions until such
time as the Division approves the transfer request.
3. Failure to abide by the conditions and limitations contained in this permit may
subject the Permittee to enforcement action by the Division of Water Quality, in
accordance with North Carolina General Statute 143-215.6A to 143-215.6C.
4. The issuance of this permit does not preclude the Permittee from complying with
any and all statutes, rules, regulations, or ordinances, which may be imposed by
other government agencies (local, state, and federal) having jurisdiction.
5. In the event that the facilities fail to perform satisfactorily, including the creation
of nuisance conditions, the Permittee shall take immediate corrective action,
including those as may be required by this Division, such as the construction of
additional or replacement stormwater management systems.
6. The permittee grants DENR Staff permission to enter the property during normal
business hours for the purpose of inspecting all components of the permitted
stormwater management facility.
7. The permit issued shall continue in force and effect until revoked or terminated.
The permit may be modified, revoked and reissued or terminated for cause. The
filing of a request for a permit modification, revocation and re -issuance or
termination does not stay any permit condition.
Page 6 of 9

State Stormwater Management Systems
Permit No. SW7111105MOD
8. Unless specified elsewhere, permanent seeding requirements for the stormwater
control must follow the guidelines established in the North Carolina Erosion and
Sediment Control Planning and Design Manual.
9. Approved plans and specifications for this project are incorporated by reference
and are enforceable parts of the permit.
10. The issuance of this permit does not prohibit the Director from reopening and
modifying the permit, revoking and reissuing the permit, or terminating the permit
as allowed by the laws, rules and regulations contained in Session Law 2008-
211, Title 15A NCAC 21-1.1000, and NCGS 143-215.1 et.al.
11. The permittee shall notify the Division of any name, ownership or mailing
address changes at least 30 days prior to making such changes.
12. This permit shall be effective from the date of issuance until November 29, 2021.
Application for permit renewal shall be submitted 180 days prior to the expiration
date of this permit and must be accompanied by the processing fee.
Permit issued this the 22nd day of August, 2012.
ENVIRONMENTAL MANAGEMENT COMMISSION
for
Division of Water Quality
By Authority of the Environmental Management Commission
Stormwater Permit No. SW7111105 Modification
Page 7 of 9

State Stormwater Management Systems
Permit No. SW7111105MOD
Currituck Community Park & Regional Aviation & Technical Training Center
Stormwater Permit No. SW7111105 Modification
Currituck 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 specification:
Signature
Registration Number
Date
SEAL
Page 8 of 9

State Stormwater Management Systems
Permit No. SW7111105MOD
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.
3. 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 outlet/bypass structure elevations are per the approved plan.
6. The outlet structure is located per the approved plans.
7. Trash rack is provided on the outlet/bypass structure.
8. All slopes are grassed with permanent vegetation.
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. The permitted amounts of surface area and/or volume have been
provided.
12. Required drawdown devices are correctly sized per the approved plans.
13. All required design depths are provided.
14. All required parts of the system are provided, such as a vegetated shelf,
and a forebay.
15. The required system dimensions are provided per the approved plans.
cc: NCDENR-DWQ Washington Regional Office
Currituck County Planning/Building Inspections
Page 9 of 9