SW7090412_CURRENT PERMIT_20090504

STORMWATER DIVISION CODING SHEET
POST -CONSTRUCTION PERMITS
PERMIT NO. I SW
DOC TYPE CURRENT PERMIT
APPROVED PLANS
❑ HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE( g(�
YYYYM M D D

jA LA)aRo
NC® NR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins Dee Freeman
Governor Director Serretnry
Mr. Scott Hinton, Airport Manager May 4, 2009
Elizabeth City — Pasquotank County Airport Authority
1028 Consolidated Road
Elizabeth City, NC 27909
Subject: Stormwater Permit No. SW7090412
Elizabeth City — Pasquotank Regional Airport
Corporate Hangar Expansion
High Density Commercial Wet Pond Project
Pasquotank County
Dear Mr. Hinton:
The Washington Regional Office received a complete Stormwater Management Permit
Application for Elizabeth City — Pasquotank Regional Airport — Corporate Hangar Expansion
on April 24, 2009. 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. SW7090412 dated May 4, 2009,
for the construction of the subject project.
lti �3v 1�1
This permit shall be effective from the date of issuance until May 4, 2019, and shall be subject
to the conditions and limitations as specked 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, 6714 Mail Service Center, Raleigh, NC 27699-6714. 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 Samir Dumpor, or me at [phone].
ncerely,
AI H 5d r—=
Regional Supervisor
Surface Water Protection Section
AH/sd: J:\WPDATA\WQS\SD\Permits — Wet Pond\SW7090412
cc: Sean Robey, PE, Hyman and Robey, PC
Pasquotank County Building Inspections
L/1Washington Regional Office
Central Files
North Carolina Division or Water Quality Internet: awwwNitcmualin OF
943 Washington Square Mall Phone [phone] One
Washington, NC 27889 FAX [phone] NorthCaroltna
An Equal Opportunely/Affirmative Action Employer- 50% Recycled/10% Post Consumer Paper NaturQi{,l'

State Stormwater Management Systems
Permit No. SW7090412
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
STATE STORMWATER MANAGEMENT PERMIT
HIGH DENSITY 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
Elizabeth City — Pasquotank County Airport Authority
Elizabeth City — Pasquotank Regional Airport — Corporate"Hangar Expansion
Pasquotank County
FOR THE
construction, operation and maintenance of a wet detention pond 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 May 4, 2019, 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. This stormwater system has, been approved for the management of stormwater
runoff as described in Section 1.6. on page 3 of this permit. The stormwater .
control has been designed to handle the runoff from 128,565 square feet of
impervious area:
3. The tract will be limited to the amount of built -upon area indicated in Section 1.7
on page 3 of this permit, and per approved plans.
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 permitted drainage, area of this
project must be directed into the permitted stormwater control system.
6. The built -upon areas associated with this project shall be located at least 50 feet
landward of all perennial and intermittent surface waters.
Page 2 of 7

State Stormwater Management Systems
Permit No. SW7090412
7. The following design criteria have been provided in the wet detention pond and
must be maintained at design condition:
a. Drainage Area, ft2:
194,796
b. Total Impervious Surfaces, ft2:
128,565
1.5
C. Design Storm, inches:
d. Pond Depth, feet:
5.5
e. TSS removal efficiency.
90%
f. Permanent Pool Elevation, FMSL:
f�2:
2.0
13,636
g. Required Permanent Pool Surface Area,
h. Provided Permanent Pool Surface Area, ft :
16,001
i. Required Storage Volume, ft
17,718
1 Permitted Storage Volume, ft3:
FMSL:
21,710
3.15
k. Temporary Storage Elevation,
I. Controlling Orifice:
2.5"0 pipe
M. Permitted Forebay Volume, ft3:
7,674
n. Receiving Stream/River Basin:
Pasquotank River/
Pasquotank River Basin
o. Stream Index Number:
30-3-(12)
P. Classification of Water Body:
"SB"
II. SCHEDULE OF COMPLIANCE
1. 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. Mowing 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. The permittee shall submit to the Division of Water Quality an annual summary
report of the maintenance inspection records for each BMP. The report shall
summarize the inspection dates, results of the inspections, and the maintenance
work performed at each inspection.
6. Access to the stormwater facilities shall be maintained via appropriate
easements at all times.
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
Page 3 of 7

State Stormwater Management Systems
Permit No. SW7090412
supporting data.
8. 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. . . .
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, leas&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 per 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, prior to construction.
13. A_copy of the approved plans and specifications shall be maintained on file by
the Permittee for the life of the project.
Ill. 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
Page 4 of 7

State Stormwater Management Systems
Permit No. SW7090412
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.
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 2H.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 May 4, 2019.
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 4th day of May, 2009.
TH CIAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
7
for oleen . ul ins, irector
Division of Water Quality
By Authority of the Environmental Management Commission
Page 5 of 7

State Stormwater Management Systems
. - Permit No. SW7090412
Elizabeth City — Pasquotank Regional Airport — Corporate Hangar. Expansion
Stormwater Permit No. SW7090412
Pasquotank Countv
Designer's Certification
1, 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 6 of 7

State Stormwater Management Systems
Permit No. SW7090412
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 Regional Office
Pasquotank County Building Inspections
Page 7 of 7

APR 2 4 2009 State of North Carolina
Department of Environment and Natural Resources
NC ®ENR Division of Water Quality
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):
Elizabeth City-Pasquotank County Airport Authority
2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance):
Scott Hinton, Aiport Manager
3. Mailing Address for person listed in item 2 above:
1028 Consolidated Road
City:Elizabeth City State:NC Zip: 27909
Phone: (252 ) 335-5634 Fax: (252 ) 335-0504
Email: [e-mail]
4. Project Name (subdivision, facility, or establishment name -should be consistent with project name on plans,
specifications, letters, operation and maintenance agreements, etc.):
Elizabeth City - Pasquotank Regional Airport
Corporate Hangar Expansion
5. Location of Project (street address):
1028 Consolidated Road
City:Elizabeth City County:Pasquotank Zip:27909
6. Directions to project (from nearest major intersection):
From the intersection of US 17 Bus and NC 344, travel south on NC344 approx. 4.5 miles to SR 1131. Turn
left on SR_1131 (Consolidated Rd) - project is on the left.
7. Latitude:36° 16' " N Longitude:76° 11' " W of project
8. Contact person who can answer questions about the project:
Name:Sean C. Robey, PE Telephone Number: (252 ) 335-1888
Email:[e-mail]
II. PERMIT INFORMATION:
1. Specify whether project is (check one): ®New ❑Renewal ❑Modification
2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the
existing permit number and its issue date (if known)
3. Specify the type of project (check one):
❑Low Density ®High Density []Redevelop []General Permit ❑Universal SMP []Other
4. Additional Project Requirements (check applicable blanks; information on required state permits can be
FonnSWU-101 Version09.25.08 Page I of

obtained by contacting the Customer Service Center at 1-877-623-6748):
❑CAMA Major ®Sedimentation/Erosion Control 0404/401 Permit ®NPDES Industrial Stormwater
III. PROJECT INFORMATION
1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative
(one to two pages) describing stormwater management for the project.
Stormwater runoff will be collected and routed to a wet detention basin designed for 90% TSS removal.
2. Stormwater runoff from this project drains to the Pasquotank River basin.
3. Total Property Area: +/- 25 acres 4. Total Coastal Wetlands Area: N/A acres
5. Total Property Area (3) — Total Coastal Wetlands Area (4) = Total Project Area'":5.39 acres
6. (Total Impervious Area / Total Project Area) X 100 = Project Built Upon Area (BUA):59 %
7. How many drainage areas does the project have?2
8. Complete the following information for each drainage area. If there are more than two drainage areas in the
Project, attach an additional sheet with the information for each area rovided in the same format as below.
For high density projects, complete the table with one drainage area for each engineered stormwater device.
Basin Information
Drainage Area 1
Drainage Area
Receiving Stream Name
Pasquotank Kiver
Pasquotank River
Stream Class & Index No.
Total Drainage Area s
On -site Drainage rea s
Off -site Drainage Area s
Existing Impervious Area (sf)
to be remove
to be remove
Proposed Impervious Area (sf)
81,115
% Impervious Area (total)
a
Impervious Surface Area
Drainage Area I
Drainage Area
On -site Buildings s
n-sit RtX s (ranps/
) prop + ex
prop + 2,386 ex
On -site Parking s
On -site Sidewalks (sf)
Other on -site s(future
development)
(future development)
Off -site s
ex + ppropose +
622 future develo ment)
existing + uture
development)
total s :
Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas,
sidewalks, gravel areas, etc.
"Total project area shall be calculated to exclude Coastal Wetlands from use when calculating the built upon area
percentage calculation. This is the area used to calculate overall percent project built upon area (BUA).
S6,'i3e
9. How was the off -site impervious area listed above derived?Topographical survey of existing off -site ares and
the proposed off -site areas have been determined by design.
Projects in Union County: Contact the DWQ Central Office staff to check to see if you project is located
within a Threatened & Endangered Species watershed that may be subject to more stringent stormwater
requirements.
IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
Form SWU-101 Version 09.25.08 Page 2 of

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 http://h2o.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 DRPC-4
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 [phone] for the status and
availability of these forms. Forms can be downloaded from httl2:Hh2o.enr.state.nc.us/su/bmp forms.hhn.
Form SW401-Low Density
Form SW401-Curb Outlet System
Form SW401-Off-Site System
Form SW401-Wet Detention Basin
Form SW401-Infiltration Basin
Form SW401-Infiltration Trench
Form SW401-Bioretention Cell
Form SW401-Level Spreader
Form SW401-Wetland
Form SW401-Grassed Swale
Form SW401-Sand Filter
Form SW401-Permeable Pavement
Form SW401-Cistern
Low Density Supplement
Curb Outlet System Supplement
Off -Site System Supplement
Wet Detention Basin Supplement
Infiltration Basin Supplement
Underground Infiltration Trench Supplement
Bioretention Cell Supplement
Level Spreader/Filter Strip/Restored Riparian Buffer Supplement
Constructed Wetland Supplement
Grassed Swale Supplement
Sand Filter Supplement
Permeable Pavement Supplement
Cistern Supplement
Form SWU-101 Version 09.25.08 Page 3 of 4

VI. SUBMITTAL REQUIREMENTS
Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ).
A complete package includes all of the items listed below. The compplete application package should be
submitted to the appropriate DWQ Office. (Appropriate office may be found by locating project on the
interactive online map at htip://h2o.enr.state.nc.us/su/msi mans.htm)
Please indicate that you have provided the following required information by initialing in the space provided
next to each item.
Ini 'als
• Original and one copy of the Stormwater Management Permit Application Form
• Original and one copy of the Deed Restrictions & Protective Covenants Form (if
required as per Part IV above)
• Original of the applicable Supplement Form(s) and O&M agreement(s) for each BMP -
• Permit application I�processing fee of $505 (Express: $4,000 for HD, $2,000 for LD)
pa able to NCDEN•�iti
• Calculations & detailed narrative description of stormwater treatment/management Lt
• Copy of any applicable soils report L�
• Two copies of plans and specifications (sealed, signed & dated), including: 7�
- Development/Project name
- Engineer and firm
- Legend
- North arrow
- Scale
- Revision number & date
- Mean high water line
- Dimensioned property/project boundary
- Location map with named streets or NCSR numbers
- Original contours, proposed contours, spot elevations, finished floor elevations
- Details of roads, drainage features, collection systems, and stormwater control measures
- Wetlands delineated, or a note on plans that none exist
- Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations
- Drainage areas delineated
- Vegetated buffers (where required)
VII. AGENT AUTHORIZATION
If you wish to designate authority to another individual or firm so that they may provide information on your
behalf (such as additional information requests), please complete this section. (ex, designing engineer or firm)
Designated agent (individual or firm):Hyman and Robey, PC
Mailing Address:P. O. Box 339
City:Camden State:NC Zip:27921
Phone: [phone] Fax: (252 ) 338-5552
Email:[e-mail]
VIII. APPLICANTS CERTIFICATION
1, (print or type name of person listed in General Information, item 2) Scott Hinton, Airport Manager
certify that the information included on this permit application form is, to the best of my knowledge, correct and
that the project will be constructed in conformance with the approved plans, that the required deed restrictions
and protective covenants will be recorded, and that the proposed project complies with the requirements of 15A
NCAC 2H .1000.
Signature: �4� Date:
Form SWU-101 Version 09.25.08 Page 4 of 4

EXPRESS Permit Number:
(to be provided by DWQ)
APR 2 4 2009 Drainage Area Number:
Wet Detentinn 8moperation 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:
Potentialproblem:
How I will remediate theproblem:
The entire BMP
Trash/debris is present.
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.
Vegetation is too short or too
Maintain vegetation at a height of
long.
approximately six inches.
Form SW401-Wet Detention Basin O&M-Rev.4 Page I of 4

Permit Number:
(to be provided by DWQ)
Drainage Area Number:
BMP element:
Potentialproblem:
How I will remediate theproblem:
The inlet device: pipe or
The pipe is clogged.
Unclog the pipe. Dispose of the
Swale
sediment off -site.
The pipe is cracked or
Replace the pipe.
otherwise damaged.
Erosion is occurring in the
Regrade the Swale if necessary to
Swale.
smooth it over and provide erosion
control devices such as reinforced
turf matting or riprap to avoid
future problems with erosion.
The forebay
Sediment has accumulated to
Search for the source of the
a depth greater than the
sediment and remedy the problem if
original design depth for
possible. Remove the sediment and
sediment storage.
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Erosion has occurred.
Provide additional erosion
protection such as reinforced turf
matting or riprap if needed to
prevent future erosion problems.
Weeds are present.
Remove the weeds, preferably by
hand. If pesticide is used, wipe it on
the plants rather than spraying.
The vegetated shelf
Best professional practices
Prune according to best professional
show that pruning is needed
practices
to maintain optimal plant
health.
Plants are dead, diseased or
Determine the source of the
dying.
problem: soils, hydrology, disease,
etc. Remedy the problem and
replace plants. Provide a one-time
fertilizer application to establish the
ground cover if a soil test indicates
it is necessary.
Weeds are present.
Remove the weeds, preferably by
hand. If pesticide is used, wipe it on
the plants rather than spraying.
The main treatment area
Sediment has accumulated to
Search for the source of the
a depth greater than the
sediment and remedy the problem if
original design sediment
possible. Remove the sediment and
storage depth.
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Algal growth covers over
Consult a professional to remove
50% of the area.
and control the algal growth.
Cattails, phragmites or other
Remove the plants by wiping them
invasive plants cover 50% of
with pesticide (do not spray).
the basin surface.
Form SW401-Wet Detention Basin O&M-Rev.4 Page 2 of 4

Permit Number:
(to be provided by DWQ)
Drainage Area Number:
BMP element.
Potentialproblem:
How I will remediate theproblem:
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 5.5 feet in the main pond, the sediment
shall be removed.
When the permanent pool depth reads 4.5 feet in the forebay, the sediment
shall be removed.
Sediment Removal
Bottom
-2.5 I 1
------------------
BASIN DIAGRAM
Ull in the blanks)
tft Min.
Sediment
Storage
Permanent Pool Elevation 2.0
Sediment Removal Elevation_ 35 volume
Bottom Elevation 4.5 1 1-ft
Storage
FOREBAY
MAIN POND
Form SW401-Wet Detention Basin O&M-Rev.4 Page 3 of 4

Permit Number:
(to be provided by DWQ)
I acknowledge and agree by my signature below that I am responsible for the
performance of the maintenance procedures listed above. I agree to notify DWQ of any
problems with the system or prior to any changes to the system or responsible party.
Project name: EC-Pasquotank Regional Airport - Corporate Hangar Expansion
BMP drainage area number:
Print name:Scott Hinton
Title:Airport Manager, Elizabeth City - Pasquotank Regional Airport
Address:1028 Consolidated Road, Elizabeth City, NC 27909
Note: The legally responsible party should not be a homeowners association unless more than 50% of
the lots have been sold and a resident of the subdivision has been named the president.
a Notary Public for the State of
County of (�GSC��gr�1� do hereby certify that
personally appeared before me this I (,I'
day of O 1 �r�cicL, and acknowledge the due execution of the
forgoing wet detention basin maintenance requirements. Witness my hand and official
seal,
\\\\\\\\\\I I I I I I I I I
�PNNE...
aoraq`':9'
`u''•AUBLIG 'U•`
f>G' •........
OTxt NK GO
SEAL
My commission expires iO-I �- 13
Form SW401-Wet Detention Basin O&M-Rev.4 Page 4 of 4

Permit
,i yeti t.@e,
i1
(to ba pmvieed by DWO)
APR 2 4 2009
NCDENR
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 111) must be printed, filled out and submitted along with all of the required information.
p: rnwtla mrVKwlAnvn
Project name
Contact person
Phone number
Dale
Drainage area number
0
�0F WArF9oc
659
� r
O Y
Ill. DESIGN INFORMATION
Site Characteristics
Drainage area
194,796 ft2 t/
Impervious area, post -development
128,565 ft2 ✓
% impervious
66.00 % ✓
Design rainfall depth
1.5 in 1/
Storage Volume: Non -SA Waters
Minimum volume required
17,718 113 OK
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 stone peak flow required?
1-yr, 24-hr rainfall depth
Rational C, pre -development
Rational C, post -development
Rainfall intensity: l-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 pod elevation
Permanent pool elevation
SHWT elevation (approx. at the pens. pool elevation)
Top of 1011 vegetated shelf elevation
Bottom of 1011 vegetated shelf elevation
Sediment deanout, top elevation (bottom of pond)
Sediment deanout, bottom elevation
Sediment storage provided
Is there addibonal volume stored above the state -required temp, pool?
Elevation of the lop of the additional volume
21,710 ft1
OK, volume provided is equal to or in excess of volume required.
fts
it
It
0P
N'
N in or'
3.4 in t/
0.38 (unitless)
0.68 (uniffess)
3.40 inthr ✓OK
5.78 ftllsec
10.33 01sec
4.55 ft2lsec
3.15 fmsl
2.00 Imsl
2.00 fmsl
2.50 frost
1.50 fmsl /
-3.50 Ins]
-0.50 fmsl
NN✓/
It
N (Y or N)
foist
Form SW401-Wet Detention Basin-Rev.5 Pens I d 11. Design Summary. Page 1 of 2

Permit No.
no be Wded by FWD)
Area, temporary pool
Area REQUIRED, permanent pool
SAIDA ratio
Area PROVIDED, permanent pod, A._,,
Area, bottom of IN vegetated shelf, A. sser
Area, sediment deanout, top elevation (bottom of pond), Ab,.,
Volumes
Volume, temporary pool
Volume, permanent pool, Vp„eym
Volume, forebay (sum of forebays 9 more than one frebay)
Forebay % of permanent pool volume
SAIDA Table Data
Design TSS removal
Coastal SAIDA Table Used?
MountaiNPiedmonl SAIDA Table Used?
SAIDA ratio
Average depth (used in SAIDA table):
Calculation option 1 used? (See Fgure 10-2b)
Volume, permanent pool, Vpe .
Area provided, permanent pool, Aoam.ma
Average depth calculated
Average depth used in SAIDA, de„ (Round to nearest 0.5ft)
Calculation option 2 used? (See Figure 10-215)
Area provided, permanent pool, A,_,y
Area, bottom of 1 Oft vegetated shelf, Aw, s,,a
Area, sediment deanout, top elevation (bottom of pond), Am.
'Depth' (distance bIw bottom of 1Oft shelf and top of sediment)
Average depth calculated
Average depth used in SAIDA, d., (Round to nearest 0.5ft)
Drawdown Calculations
Drawdown through orifice?
Diameter of office (if circular)
Area of office (if-non-arcular)
Coefficient of discharge (Co)
Driving head (He)
Drawdown through weir?
Weir type
Coefficient of discharge (C.)
Length of weir (L)
Driving head (H)
Pre -development 1-yr, 24-hr peak flow
Post -development 1-yr, 24-hr peak flow
Storage volume discharge rate (through discharge onfice or weir)
Storage volume drawdown time
Additional Information
Vegetated side slopes
Vegetated shelf slope
Vegetated shelf width
Length of flowpath to width ratio
Length to width ratio
Trash rack for overflow & orifice?
Freeboard provided
Vegetated filter provided?
Recorded drainage easement provided?
Capures all runoff at uMmate build-0d?
Drain mechanism for maintenance or emergencies
21,838 It'
13,636 fl'
7.00 (unitless)
16,001 fl' OK
8,711 if
2,274 f
21,710 is " `/ OK
40,334 fl'
7,674 it'
19.0% % OK
90 % V
y (Y or N) /
in (Y or N)
7.00 (unitless)
n (Y or N)
fl'
it,
it
It
y (Y orXN)16,001 (YOK
8,711 It'OK
2,274 rye /•V/ OK
500 a\ OK
3.40 ft✓ OK
3.5 RV OK
y (Y or N) /
2.50 in
in'
0.60 (unitless)
1.15 it
N (Y at N)
(unitless)
(unNess)
If
ft
5.78 ft'/sec sufficient pre -development peak flow.
10.33 ft Isec //OK
010 fl'Isec j/ /
2.50 days 1// OK, draws down in 2-5 days.
Drawdown time varying from expected value by more than a half day.
3 :1 V / OK
10 :1 VVV OK
10.0 it OK
6 :1 OK
7.0 :1 OK
Y (Y or N) OK
3.9 it OK
N (Yor N)J OK
N (Y or N) Insufficient. Recorded drainage easement required.
Y (Y or N) JOK
Form SW401-Wet Detention Basin -Rev 5 Pens I. & H. Design Summary, Page 2 or 2

Permit
(to be provided by DWO)
Ills,`REQUIRED,ITEMSCHECKLIS.T ": ti ', x .mac_;...... :. `.:,_t=7, °' tla� 3"C:";`'' .;.'_.?'-.`•.y
Please indicate the page or plan sheet numbers where the supporting documentation can be found. An 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. If a
requirement has not been met, attach justification.
Page/ Plan
Initials
Sheet No.
1. Plans (1' - 5V 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.
fNv r 1
3
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.
Ia,V r I
3
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 cutlet structures.
kd hh
Z
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.
`(r�
r2+ )
06chmn
5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay,
p
2
to verify volume provided.
Ilc(..L r 1
6. A construction sequence that shows how the wet detention basin will be protected from sediment until the
entire drainage area is stabilized.
4+k Meri f
7. The supporting calculations.
{{
J�LfJ
ttiTrtfn>`
8. A copy of the signed and notarized operation and maintenance (O&M) agreement.
IV p,
9. A copy of the deed restrictions (if required).
) I 1
k#CL-�nV10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
hqn ati J?_
soil maps are not an acceptable source of soils information.
Form SW401-Wet Detention Basin-Rev.5 Part III. Required Items Checklist, Page 1 of 1

s''7°q°�z
Oviz�'UJ
STORMWATER SUBMITTAL REQUIREMENTS
WET DETENTION POND
Objective
A. Collect all runoff from all BUA (proposed and/or existing and/or offsite) as the case may be,
by any means including piping or swales; and direct it to the pond.
B. Check the proposed pond design to make sure it meets or exceeds the minimum design
criteria for surface area, volume and drawdown.
II. What makes up a complete wet detention pond application package?
A. Two sets of sealed, signed & dated layout & grading plans with appropriate details.
(Additional sets of plans may be requested for projects in certain counties)
B. Completed application with supplement(s), SWU-101, SW401-Wet Pond, and inspection and
maintenance agreements.
C. Deed restriction document, if applicable (for subdivisions & projects with out parcels)
D. Sealed, signed & dated calculations.
E. Estimated seasonal high water table elevation at all pond locations.
F. Chlorides test results must be provided if the project is within''/2 mile of SR waters (Phase II).
(This is only required to test out of SR water treatment requirements)
III. BIMS entry (for DWQ use only)
Enter & track application acknowledged date, review date, add info requested/received dates, permit
issue dates, and drainage area info. Best done after the add info letter is written and before sending
permit up for signature.
IV. Shell documents (for DWQ use only)
Permit shells: s:\wqs\stormwater\shells\highcompond
s:\wqs\stormwater\shells\highsubpond
s:\wqs\stormwater\shells\HDhybrid
Spreadsheet: s:\wqs\stormwater\excel spreadsheets\pond
VI. Review Procedure
A. APPLICATION
1, V An original signature is required. Photocopied signatures cannot be accepted.
2.VA,completed wet detention pond supplement and a signed, dated and notarized wet
detention pond Inspection and Maintenance Agreement with an original signature.
3. VThe numbers on the supplement match up to the numbers used in the calculations and
shown on the plan details.
4.✓Built-upon areas are reported in square feet in Section 111.6.
2 5. Receiving stream name and classification. This is important because in the non -Phase
11 counties, a wet pond cannot be used on a project that is within'/2 mile of and draining
to SA waters. For Phase 11, a wet pond is allowed within '/z mile of SA waters.
6.V'Section 111.6 is filled in -cannot be left blank. One column must be filled in for each
7.j//proposed wet pond.
If the applicant is a corporation, partnership or LLC, look it up on the Secretary of State
Corporations Database. Make sure corporation is spelled correctly (capitalization and
punctuation matter) and that the person signing the application is at least a vice-
president in the corporation, a General Partner in the partnership, a member in a
member -managed LLC, or the manager of a manager -managed LLC. Need
documentation to support if the Articles of Incorporation do not list the members or
managers of the LLC. If an agent signs, then a letter of authorization is needed from the
president, vice president, general partner, member or manager.
8.�kFor subdivided projects, a signed and notarized deed restriction statement must be
provided.

Wet Detention Pond, cont.
B. CALCULATIONS
1. V The orifice is sized based on drawing down the calculated minimum volume in 2-5
days. The average head to use in the orifice equation is approximately one-third of
the distance between the permanent pool elevation (PPE) and the elevation of the
next available outlet above the permanent pool. The elevation of the next available
outlet must be either the elevation where the minimum volume is provided, or it can
be higher. The temporary pool elevation (TPE) to report on the supplement will be
the elevation of the next available outlet above the PPE. The temporary pool volume
(TPV) to report on the supplement is the volume between the specified PPE and the
TPE.
2�/�i�or Phase II projects that are within %2 mile of and draining to SR waters, the
difference in runoff from the predevelopment and post -development conditions for
V,1the 1 year 24 hour storm must be controlled and treated.
3�✓�AFor Phase II projects, the discharge rate leaving the pond can be no more than the
�pre -development discharge rate for the 1 year 24 hour storm.
AFor Phase II projects draining to SA water, no discharge to surface waters may occur
from wet ponds. The discharge leaving the orifice must be effectively infiltrated prior to
reaching surface waters.
5. /The average pond depth is the permanent pool volume divided by the permanent pool
surface area. The result must be between 3 ft. and 7.5 ft. Parts of the pond can be
/deeper than 7.5 ft., but in no case can any part of the pond be less than 3 ft deep.
6. If the 85 /c SS-chartq sed a 30' vegetated filter must be provided at the outlet of the
/pond. If tlltiie 90% TSS - art is used, no filter is required.
7. v Use the correct-SA/DA TSS chart from the BMP Manual noting that there are different
charts for different areas of the State.
8. v Required surface area at permanent pool.
9. ' /Provided surface area at permanent pool (Based on pond dimensions)
10. y Required volume calculation based on 1.5" storm for Phase I I projects' and 1" storm for
all,others projects. "unless the project is Phase II and within '/ mile of and draining to
SR waters then the volume calculation must be based on difference between the pre
' /and post development conditions for the 1-yr 24-hr storm.
11. V Table of elevations, areas, incremental volumes and accumulated volumes for overall
pond and for forebay, to verify volumes provided.
12. Forebay designed to hold 20% of the permanent pool volume. (Range of 18%-22%
130 lo4rosive flow for 10 yr. storm in the vegetated filter, if using 85% TSS.
14.VThe seasonal high water table must be at or below the proposed permanent pool
elevation to assure that the necessary volume will be available above the permanent
pool.
15. Rounding numbers off during the calculation process can result in deficiencies. Do not
16✓round the numbers until you get to the final result.
An additional one foot must be excavated below the bottom elevation of the pond. The 1
foot sediment accumulation depth is not included in the average`depth calculation.

Wet Detention Pond, Cont.
C. PLANS- Due to storage space constraints, plan sheets should be kept to a minimum. For
small commercial single wet pond projects, the plan set could consist of only 2 or 3 sheets,
layout, grading and details. For larger projects, show as much information as possible on as
few sheets -as possible, without cluttering them up.
1. VQ6elopment/Project Name
2.i/Engineer name and firm.
4.VNorth Arrow
5. ✓Location Map with nearest intersection of two major roads shown. Major road is any 1,
2; or 3 digit NC, US or interstate highway.
6. ✓Scale- standard engineering scale, no off-the-wall stuff.
7.t/Dafe
8.t/R6ision number and date, if applicable.
9. (/Original contours, proposed contours, spot elevations, finished floor elevations, pipe
inverts, swale inverts, etc.
10.✓Existing drainage (piping, swales, ditches, ponds, etc.), including off -site. Include a map
delineating the offsite drainage areas.
11 Vfoperty/Project boundary lines, bearing & distances.
12/1 can High Water Line or Normal High Water Line, if applicable.
13.VThe permanent pool elevation must be above the SHWT and above the lowest
elevation of adjacent wetlands. Evaluate the need for a liner and/or berm/slurry wall to
prevent dewatering the wetland.
14 A6rainage easement widths, pipe sizes and swale inverts are provided.
15. etlands delineated, or a note on the plans that none exist. Get a copy of the wetlands
delineation map signed by the Corps of Engineers, or have the applicant include a copy
ofRhe unsigned delineation map submitted to the Corps. Wet ponds may not be located
in wetlands unless a permit to fill those wetlands has been obtained.
16VDetails for the roads, parking, cul-de-sacs, including sidewalk width, radii, dimensions &
pes.
14partment / Condo development- Provide a typical building footprint with dimensions
and note all concrete and wood deck areas.
18.'VThe drainage area for each wet pond is clearly delineated and numbered to match up to
the calculations and supplement. Drainage area delineation is best done as a separate
plan sheet.
19VA pond section detail to include the forebay, a 10 foot wide vegetated shelf, pertinent
elevations for the bottom, permanent pool, temporary pool, and SHWT, 3:4 slopes
above the permanent pool, and the weir elevation between the main pond and the
forebay.
20✓The 10 vegetated shelf extends 6" below and 6" above the permanent pool elevation.
21 VAn outlet structure detail showing a trash rack with <_6" square openings, the necessary
orifice invert elevation (i.e., the permanent pool), orifice size and temporary pool
elevation.
22� imensions for each line and arc formed by the permanent pool contour.
2*/f9Vhere the 85% TSS chart was used, a 30 ft. vegetated filter strip is required to be
shown on the plans & detailed (elevations, inverts, slopes, and flow spreader
/mechanism). Please note that the filter strip is not a ditch.
24V A forebay is provided for each inlet and located so as to prevent short-circuiting.
25VThe pond must have a minimum 1.5:1 length to width ratio and a minimum 3:1 flow path
length. Artificial "baffles" of timber, vinyl, or earth can be used to create a longer flow
path. The top elevation of the baffle should be set at the temporary pool elevation or
Higher.
26.VA/Vegetation plan is specified for the pond, including slopes. Wetlands species are
listed for planting on the 10:1 shelf. Weeping Love Grass is not suitable as a permanent
vegetated cover for pond slopes.
2 All roof drainage must be directed to the pond. Show the roof drain collection lines on
the plan. This is necessary for projects where the buildings back up the property lines
where roof drainage may leave the site prior to going through the pond.