SW8050801_HISTORICAL FILE_20050812

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

State Stormwater Management Systems
Permit Number SW8 050801
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
STATE STORMWATER MANAGEMENT PERMIT
HIGH DENSITY DEVELOPMENT
SERVED BY AN OFF -SITE STORMWATER CONTROL
AND AN ALTERNATIVE CONTROL SYSTEM
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 1S HEREBY GRANTED TO
Mr. Jon W. Rosborough and New Hanover County Airport Authority
Wilmington International Airport General Aviation Apron Expansion
New Hanover County
FOR THE
construction of impervious areas with runoff to be treated in an offsite permitted stormwater
facility and a Vortechs stormwater treatment system, in compliance with the provisions of
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. The stormwater runoff from the site will be routed to a Vortechs Model No. 7000
and an extended dry detention basin, the latter currently operated and maintained by New
Hanover County Airport Authority under the terms and conditions set forth in Permit No.
SW8 050547.
This permit shall be effective from the date of issuance until August 12, 2015, and shall be.
subject to the following specified conditions and limitations:
I. DESIGN STANDARDS
This permit is effective only with respect to the nature and volume of stormwater
described in the application and other supporting data.
2. The runoff associated with this project has been approved to be discharged into a
stormwater management system permitted under SW8 050547 and a Vortechs Model
No. 7000, as described in Sections 1.10 and 1.11 on page 3 of this permit.
3. The total built -upon area allotted by Stormwater Management Permit No. 050547, is
4,247,100 square feet. This project proposes 151,589 square feet.
4. Approved plans and specifications for this project are incorporated by reference and
are enforceable parts of the permit.
5. 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.
6. The runoff from the permitted built -upon area must be directed into the permitted
stormwater system.
Page 2of9

State Stormwater Management Systems
Permit Number SW8 050801
7. The Vortechs Stormwater Treatment unit must be designed, sized and installed per
Vortechs specifications to achieve a minimum 70% Net Annual TSS removal efficiency.
8. Quarterly monitoring of the outflow from the Vortechs Unit is required. See Section II of
this permit for specific monitoring requirements.
9. In the event that the Vortechs Unit fails to function as required, or to meet the 70% Net
Annual TSS removal efficiency minimum, the sytem shall be replaced by other
permittable stormwater management measures, such as a sand filter.
10. The following design criteria have been provided in the extended dry detention basin
and must be maintained at design conditions:
a.
Drainage Area, eicres:
150
Onsite, ft :
6,534,000
Offsite, ft2:
None
b.
Total Impervious Surfaces, ft2:
4,247,100
C.
Design Storm, inches:
1.0
d.
Basin Bottom Elevation, feet:
7 - 13
e.
TSS removal efficiency:
50
(Required Additional BMP to be
provided by tributary projects.)
f.
Storage Elevation, FMSL:
9.87
g.
Storage Surface Area, ft2:
77,200
h.
Permitted Detention Volume, ft3:
66,734
i.
Sediment Storage Volume, ft3:
20,604
j.
Seasonal High Water Table, FMSL:
6.0
k.
Controlling Orifice:
8.0"0 pipe (3.75"0 low flow)
I.
Drawdown Time for 8.0"0 orifice, hrs:
48
M.
Receiving Stream/River Basin:
Smith Creek 1 Cape Fear
n.
Stream Index Number:
18-74-63
o.
Classification of Water Body:
"C; Sw"
11% The
following design criteria have been provided in the Vortechs Model 7000 and
must be maintained at design conditions:
a.
Design Storm:
1"
b.
Drainage Area, f2:
151,589
Onsite, ft :
151,589
Offsite, ft2:
0
C.
Total Impervious Surfaces, ft2:
151,589
d.
Net Annual TSS Removal Efficiency:
70%
(followed by dry basin at 50% efficiency
for combined 85% system efficiency)
e.
Runoff Coefficient:
0.95
f.
Grit Chamber Area, ft2:
50.30
g.
Flow Rate Capacity, cfs:
11.00
h.
Design Ratio, DR:
29.5
(DR = (Tot. Drain Area) x (Runoff Coef.)
x (cfs to gpm conversion)/Grit Chamber Area)
Page 3 of 9

State Stormwater Management Systems
Permit Number SW8 050801
II. MONITORING REQUIREMENTS
1. The permittee shall submit a monitoring plan to the DWQ for approval within 60 days of
receipt of this permit, for the Vortechs Unit.
2. Quarterly monitoring of both influent and effluent is required. Samples shall consist of a
grab sample of the first flush (within the first 15 minutes of discharge from the unit) and
flow -paced composite samples collected, at a minimum over the first three hours of the
event.
3. Samples must be collected in each of the four seasons. Monitoring parameters shall
include the following at a minimum. Additional parameters may be added on a case -by -
case basis, to address water quality issues in the area.
a.
Total Suspended Solids
b.
Oil and grease
C.
TKN
d.
Ammonia Nitrogen
e.
Nitrate -Nitrite
f.
Total Phosphorous
g.
Total Coliform
h.
Fecal Coliform
i.
Enterococcus
j.
Flow
4. The storm event date, total rainfall and duration must be recorded for both the storm
event prior to the sampled event and the sampled event.
5. All samples shall be collected from a representative storm event. A representative storm
event is an event that measures greater than 0.1 inches.of rainfall and that is preceded
by at least 72 hours during which no storm event measuring greater than 0.1 inches has
occurred. A single storm event may contain up to 10 consecutive hours of no
precipitation. For example, if it rains for 2 hours without producing a collectible
discharge, and then stops, a sample may be collected if a rain producing discharge
begins again within the next 10 hours.
6. The permittee shall split samples with DWQ for at least two events during the first year
after the Vortechs unit is installed. The permittee shall notify the Division as soon as
possible of their intent to provide split samples .
7. Within 30 days of receiving laboratory results, the permittee shall submit copies to the
Division of Water Quality, Stormwater and General Permits Unit, 1617 Mail Service
Center, Raleigh, NC 27699-1617. All data submitted must reference the project name,
location and permit number.
8. The permittee may petition to have the monitoring requirements modified, reduced, or
eliminated only after 10 valid monitoring events for 10 different storm events have been
submitted for the system, during the course of a full year. Modification shall be
determined on a case -by -case basis.
9. An annual report shall be submitted by March 1 of each year. The report shall document
the inspection, maintenance, and monitoring activities performed during the previous
calendar year, and summarize overall system performance. The annual report shall be
submitted to NCDENR-DWQ, Stormwater and General Permits Unit, 1617 Mail Service
Center, Raleigh, NC 27699-1617.
Page 4 of 9

State Stormwater Management Systems
Permit Number SW8 050801
III. SCHEDULE OF COMPLIANCE
1. The offsite 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 associated with this project.
2. During construction, erosion shall be kept to a minimum and any eroded areas of the
system will be repaired immediately.
3. The permittee is responsible for keeping the stormwater collection system on the lot
clear of debris, and keeping the site stabilized in accordance with the requirements of
the NC Erosion and Sediment Control Design Manual.
4. New Hanover County Airport Authority, shall, at all times, provide the operation and
maintenance necessary to assure the permitted stormwater management 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 revegetation of side slopes.
d. Immediate repair of eroded areas.
e. Maintenance of side slopes in accordance with approved plans and
specifications.
f. Debris removal and unclogging of outlet structure, orifice device and catch basins
and piping.
g. Access to the outlet structure must be available at all times.
5. 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 the approved plans, regardless of size.
b. Project name changge.
c. Transfer of ownership.
d. Redesign or addition to the approved amount of built -upon area.
e. Further subdivision, acquisition or selling 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.
6. The Director may determine that other revisions to the project should require a
modification to the permit.
7. New Hanover County Airport Authority, must keep records of maintenance activities
and make them available upon request to authorized personnel of DWQ. The records
will indicate the date, activity, name of person performing the work and what actions
were taken.
8. This permit shall become voidable unless the facilities are constructed in accordance
with the conditions of this permit, the approved plans and specifications, and other
supporting data.
9. New Hanover County Airport Authority, is responsible for providing, prior to issuance
of a Certificate of Occupancy, and prior to operation of the permitted stormwater
management facility, a certification from an appropriate designer for the system
installed, certifying that the permitted facility has been installed in accordance with
Stormwater Permit No, SW8 050547, the approved plans and specifications, and other
supporting documentation. Any deviations from the approved plans and specifications
must be noted on the Certification.
Page 5 of 9

State Stormwater Management Systems
Permit Number SW8 050801
10. A cop of the approved plans and specifications shall be maintained on file by the
Permi tee for a minimum of ten years from the date of the completion of construction.
11. This lot is limited to the amount of built -upon area indicated in the supporting
calculations and per approved plans. The project must have a built -upon area less
than or equal to the amount permitted under Stormwater Permit No. SW8 050547.'
Additional built -upon area will require a modification to the overall Permit.
12. New Hanover County Airport Authority, must record any deed restrictions as required
by their permit, and they must verify that the proposed built -upon area does not
exceed the allowable built -upon area. Once the lot transfer is complete, the built -upon
area may not be revised without approval from the permittee, and responsibility for
meeting the built -upon area limit is transferred to the individual property owner.
13. The drainage features shown as a part of the stormwater management system on the
approved plan shall not be filled in, altered, or piped by an party without first
submitting a revision to the permit and receiving approval from the Division.
14. 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.
III. GENERAL CONDITIONS
This permit is not transferable except after notice to and approval by the Director. In
the event there is a desire for the facilities to change ownership, or }here is a name
change of the Permittee, a formal permit request must be submitted to the Division of
Water Quality accompanied by an application fee, documentation from the parties
involved, and other supporting materials as may be appropriate. The approval of this
request will be considered on its merits and may or may not be approved. The
permittee is responsible for compliance with ail terms and conditions,of this permit
until such time as the Director approves the permit transfer.
2. 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.
3. 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) which have Jurisdiction.
4. In the event that the offsite stormwater facilities fail to perform satisfactorily, including
the creation of nuisance conditions, New Hanover County Airport Authority is
responsible for taking immediate corrective action, including those as may be required
by phis Division, such as the construction of additional or replacement stormwater
management systems.
5. The permittee grants permission for DENR Staff to enter the property for the purpose
of inspecting ail components of the permitted stormwater management facility.
6. The permit may be modified, revoked and reissued or terminated for cause. The filing
of a request for a permit modification, revocation and reissuance or termination does
not stay any permit condition.
Page 6 of 9

State Stormwater Management Systems
Permit Number SW8 050801
7. The permittee shall notify the Division of any name, ownership or mailing address
changes within 30 days.
Permit issued this the 1 2th day of August 2005.
NORTH CAROUNA ENVIRONMENTAL MANAGEMENT COMMISSION
/or Alan VV. KIImeK, N.C., uirector
Division of Water Quality
By Authority of the Environmental Management Commission
Page 7 of 9

State Stormwater Management Systems
Permit Number SW8 050801
Stormwater Project Number SW8 050801
Wilmington International Airport General Aviation Apron Expansion
New Hanover 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.
Required Items to be checked for this certification to be considered complete are on page 2
of this form.
Noted deviations from approved plans and specifications:
Signature
Registration Number
Date
SEAL
Page 8of9

State Stormwater Management Systems
Permit Number SW8 050801
Certification Requirements: �.
1. The lot contains no more than the permitted amount of built -upon area.
2. All the built -upon area associated with the project is graded such that the
runoff drains to the system.
3. The lot has been stabilized with permanent vegetation to prevent erosion.
4. Vegetated slopes are no steeper than 3:1.
5. Roof drains are located such that building runoff drains into the system.
6. The inlet from this project into the approved offsite system is located per the
approved plans and does not cause short-circuiting.
cc: NCDENR-DWQ
Tony Roberts, New Hanover County Building Inspections
Page 9 of 9

WILINGTON INTERNATIONAL AIRPORT
WILMINGTON, NORTH CAROLINA
GENERAL AVIATION APRON EXPANSION
Revised 8-4-05
PROJECT DESCRIPTION
The General Aviation Apron Expansion project at the Wilmington International Airport
consists of constructing approximately 12,000 square yards of paved asphalt surface. The
project area is located on the west side of Runway 17-35 in between the Fixed Base
Operators Air Wilmington and Aeronautics and just north of the main airport terminal
building. Expansion of the apron will provide additional parking space and movement
area for general aviation aircraft.
The project will involve demolition and removal of an existing general aviation terminal
building and removal of existing concrete and asphalt pavement. The concrete pavement
serves as part of the existing apron. The remainder of the pavement to he removed is
asphalt and consists of the existing parking lot serving the terminal building. The project
area will be graded and then paved with new asphalt pavement. Storm drain pipe and
structures will also be installed to convey storm water away from the site for treatment
and storage.
STORMWATER MANAGEMENT
The total project area is approximately 3.20 acres. The drainage area where the project is
located is approximately 3.48 acres. The project will result in a net increase in
impervious area of 1.45 acres. After construction, all 3.48 acres will be impervious
surface. There are no wetlands located on the project site and none will be disturbed
during this project.
Two new hangars and a terminal building, as shown on sheet 12 of the construction
plans, are to be built adjacent to this new apron expansion in the future. The
construction of these buildings is separate from this project and is not included in
the project drainage area. The project drainage area for this project is limited to
existing apron pavement and the new apron expansion.
Storm water will drain from the site through a series of inlets and pipes and into a
VortechnicsTM stormwater treatment system. After passing through the VortechnicsT",
unit, water will flow through pipe and into a new conveyance system currently tinder
construction which drains to the Airport's Extended Dry Detention Basin No, 1. Both the
dry detention basin and new conveyance system were recently permitted by NCDENR
(Permit No. SW8 050547). The proposed inlets and pipe are sized to accommodate the
25 year storm event. Three drop inlets will be constructed to drain the new apron surface.
Water falling on the new apron will sheet flow into the new drop inlets. Water falling on
7A�
CEIVED
G®� 2 0��/
BY: _

the apron shoulders will sheet flow away from the apron over grassed areas and
ultimately into existing inlets. The apron shoulders will be seeded and mulched and silt
fence will be used to control erosion and sediment during construction.
The VortechnicsTM storm water treatment system will be used to provide a minimum of
70% TSS removal. Combined with the 50% TSS removal provided by the Extended Dry
Detention Basin No.l, this conveyance system will meet the total required 85% TSS
removal for the drainage area.
Several project constraints made it necessary to use the VortechnicsTM storm water
treatment system, instead of a vegetative system (swale). The apron expansion will tie
into existing pavement on several sides. On the other sides of the expansion future
terminal and hangar buildings will be constructed. FAA grading requirements and NFPA
fire protection standards require water to drain away from these buildings. These
constraints would not allow any sheet flow into grassed swales or similar BMP to allow
for TSS removal. Water will be required to be drained to inlets and then piped away
from the site. Because of the relatively flat grades of the airport area and depth required
for pipe, it is impractical to pipe the water into a Swale. Because of these reasons, a
VortechnicsTM storm water treatment system is proposed. The system will be limited to
treating runoff from the paved apron.
The VortechnicsTM system will be operated and maintained and the stormwater it treats
will be monitored according to the provisions of the Preliminary Evaluation Period as
established by NCDENR. A copy of the PEP program is included in this application
package.
SOILS
A subsurface investigation was conducted for the project by GeoTechnologics, Inc.,
Raleigh, North Carolina. The subsurface investigation was completed by performing a
total of seven test borings in the project area. The borings extended to depths of ten feet
below the existing surface. The subgrade soils below the topsoil consist of loose to firm
silty sands and loose to firm poorly graded fine sands in the upper six feet of the boring.
These soils types have a Unified Soil Classification of SM and SP.
SEQUENCE OF CONSTRUCTION
The construction sequence of this project will follow normal procedures for projects of
this type, including establishment of staging area and access, installation of sedimentation
and erosion control measures, milling and removal of existing pavement, installation of
drainage structures and pipe, grading the subgrade, placing new bituminous pavement,
application of sealcoat, marking the new pavement, installation of fencing, and seeding
and mulching disturbed areas. A detailed sequence of construction has been shown on
the plans for the project. After construction in disturbed areas has been completed, the

area shall be seeded and mulched. All erosion and sedimentation control measures shall
be maintained until an acceptable stand of vegetation is established.
The following sequence of construction was developed to provide general guidance to the
contractor in developing construction sequence and schedules. In accordance with the
specifications, the contractor will provide a detailed schedule of construction to the
engineer for review and approval prior to commencing construction.
l . Establish a temporary staging area as shown on plans and set up engineer's trailer.
2. Construct necessary access route(s) and construction entrances.
3. Install Phase I temporary fencing/barricades around perimeter of project area as
shown on the plans.
4. Install temporary erosion control measures as indicated on the plans and as directed
by the engineer.
5. Remove existing chain link fence as shown on plans.
6. Remove existing bituminous pavement in parking area and existing driveway.
7. Remove existing concrete slab and old hangar door rails from hangar foundation.
8. Remove or abandon existing utilities in place as shown on the plans.
9. Remove existing concrete pavement slabs from existing apron as shown on the
plans.
10. Excavate topsoil from proposed pavement area and stockpile..
It. Install stormwater pipe and drainage structures.
12. Grade and compact existing subgrade.
13. Place and compact bituminous base course.
14. Place and compact bituminous surface course.
15. Install phase ii temporary fencing/barricades as shown on the plans.
16. Seed and mulch project area and open apron.
17. After specified waiting period, apply seal coat in areas as shown on the plans and
mark as required.
18. After substantial completion of other projects (terminal building, hangars), install
phase III fencing as shown on the plans and remove phase II temporary
fencing/barricades.
19. Remove all temporary access roads (as directed by engineer), miscellaneous
equipment, stock piles, debris, etc. from project area.
20. Restore all disturbed areas and complete seeding and mulching operations on all
disturbed areas throughout the project area.

State of North Carolina
Department of Environment and Natural Resources
Wilmington Regional Office
Michael F. Easley, Governor William G. Ross, Jr., Secretary
FAX COVER SHEET
Date: 8/3/05 No. of Pages: 3 (Inci. Cover)
To: Robert Williams From: Paul Bartlett
Company: Talbert & Bright Water Quality Section - Stormwater
FAX #: [phone] FAX #: [phone]
Phone #: [phone]
DWQ Stormwater Project Number: SW8 050801
Project Name: Wilmington Intl. Airport Gen. Aviation Apron Expansion
MESSAGE:
Robert,
A Request for Additional Information is attached. The original will be mailed to Mr.
Rosborough, and a copy will be mailed to you.
/J
ENBlptb: S:IWQSISTORMWATERIADDINFO120051050801
J
127 Cardinal Drive Extension, Wilmington, NC 28405-3845 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer

of \NATF9 Michael F. Easley, Governor
�O* QG William G. Ross, Jr., Secretary
North Carolina Department of Environment and Natural Resources
Alan W. Klimek, P.E. Director
Division of Water Quality
August 3, 2005
Mr. Jon Rosborough, Director
New Hanover County Airport Authority
1740 Airport Boulevard
Wilmington, NC 28405
Subject: Request for Additional Information
Stormwater Project No. SW8 050801
Wilmington International Airport General Aviation Apron Expansion
New Hanover County
Dear Mr. Rosborough:
The Wilmington Regional Office received a Stormwater Management Permit Application for
Wilmington International Airport General Aviation Apron Expansion on August 2, 2005. A
preliminary review of that information has determined that the application is not complete. The
following information is needed to continue the stormwater review-
1. Please provide a markup of Sheet 4 that illustrates the Project Area and Drainage Area
(hand markup by magic marker is acceptable), and review the reported drainage Area
of 3.48 acres.
2. Please correct the bypass weir elevation from 24.4 to 24.8 on Sheet 8, Section C-C of
the Bypass Weir Detail.
3. Please provide invert elevations and dimension the orifice diameter and weir opening on
Sheet 7 for the Vortechs Unit detail.
4. Please clarify in a revised Narrative whether the two future hangars and the future
terminal building illustrated on Sheet 12 are within the Project and Drainage areas for
the proposed project. Item #1 will clarify their locations by illustration.
5. After reviewing the Drainage Area in Item #1, please report the Impervious Area in
Section 111.6. of the application's lower table in square feet.
Please note that this request for additional information is in response to a preliminary review.
The requested information should be received by this Office prior to August 10, 2005, or the
application will be returned as incomplete. The return of a project will necessitate resubmittal of
all required items, including the application fee.
Nor1h Carolina Division of Water Quality 127 Cardinal Drive Extension Phone [phone] Customer Servicel-877-623-6748
Wilmington Regional Office Wilmington, NC 28405-3545 FAX [phone] Internet: h2o.enr.state.nn us One
NorthCaroll/ina
An Equal Opportunity/Affirmative Action Employer — 50% Recycled110% Post Consumer Paper Alaturall y

Mr. Jon W. Rosborough
August 3, 2005
Stormwater Application No. SW8 050801
If you need additional time to submit the information, please mail or fax your request for a time
extension to the Division at the address and fax number at the bottom of this letter. The
request must indicate the date by which you expect to submit the required information. The
Division is allowed 90 days from the receipt of a completed application to issue the
permit.
The construction of any impervious surfaces, other than a construction entrance under an
approved Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject
to enforcement action pursuant to NCGS 143-215.6A.
Please reference the State assigned project number on all correspondence. Any original
documents that need to be revised have been sent to the engineer or agent. All original
documents must be returned or new originals must be provided. Copies are not acceptable. If
you have any questions concerning this matter please feel free to call me at [phone].
Sincerely,
Paul T. Bartlett, P.E.
Environmental Engineer
ENBlptb: S:1WQSISTORMWATERIADDINFO120051050547
CC" Robert Williams, Talbert & Bright
Paul Bartlett
1►A

TAMERT& BRIGHT
August 5, 2005
Mr. Paul T. Bartlett, PE
NCDENR
127 Cardinal Drive Extension
Wilmington, NC 28405
RE: Wilmington International Airport
General Aviation Apron Expansion
AIP 3-37-0084-34; TBI No. 3301-0406
Stormwater Project No. SW8 050801
Dear Paul:
Please find enclosed additional information as requested in your letter dated August 3, 2005 in
regards to the Stormwater Management Permit Application package for the General Aviation
Apron Expansion project at the Wilmington International Airport. Two copies of each of the
following materials are enclosed:
I . Sheet 4 showing Project Area and Drainage Area
2. Sheet 8 showing bypass weir elevation of 24.80'
3. Sheet 7 showing inverts and dimensions of orifice and weir for Vortechs Unit
4. Revised Project Narrative
5. Revised Application Form — Page 2-Section III.6.-"fable
Please call me if you have any questions or need additional information.
Sincerely,
Robert Williams. EI 7AUG
CFIVF 7
0 5 2005
Enclosures
BY:
c: Ms Julie Wilsey, Deputy Airport Director (w/enc.)
FNGINFERING & PLANNING CONSULTANTS
WWW,TAI,li1:1'I'ANDBRIG I-1'1'.COM
4810 SHELLEY DRIVE; WILMINGTON, NC 28405 910.763.5350 FAX [phone]
WILMINGTON. NORTH CAROLINA • CHARLOTTE, NORTH CAROLINA • RICHMOND. VIRGINIA

49 1
State of North Carolina
Department of Environment and Natural Resources
Wilmington Regional Office
Michael F. Easley, Governor
FAX COVER SHEET
William G. Ross, Jr., Secretary
Date: 813105 No. of Pages: 3 (Incl. Cover)
To: Robert Williams From: Paul Bartlett
Company: Talbert & Bright Water Quality Section - Stormwater
FAX #: [phone] FAX #: [phone]
Phone #: [phone]
DWQ Stormwater Project Number: SW8 050801
Project Name: Wilmington Intl. Airport Gen. Aviation Apron Expansion
MESSAGE:
Robert,
A Request for Additional Information is attached. The original will be mailed to Mr.
Rosborough,.and a copy will be mailed to you.
ENBlptb. S:1WQSISTORMWATERIADDINF0120051050801
127 Cardinal drive Extension, Wilmington, NC 28405-3845 Telephone [phone] FAX [phone]
An Equal Opportunity Affirmative Action Employer

�QF WATF,40 Michael F. Easley, Governor
G William G. Ross, Jr., Secretary
r North Carolina Department of Environment and Natural Resources
7
Alan W. Klimek, P.E. Director
Division of Water Quality
August 3, 2005
Mr. Jon Rosborough, Director
New Hanover County Airport Authority
1740 Airport Boulevard
Wilmington, NC 28405
Subject: Request for Additional Information
Stormwater Project No. SW8 050801
Wilmington International Airport General Aviation Apron Expansion
New Hanover County
Dear Mr, Rosborough:
The Wilmington Regional Office received a Stormwater Management Permit Application for
Wilmington International Airport General Aviation Apron Expansion on August 2, 2005. A
preliminary review of that information has determined that the application is not complete. The
following information is needed to continue the Stormwater review:
1. Please provide a markup of Sheet 4 that illustrates the Project Area and Drainage Area
�, 4o (hand markup by magic marker is acceptable), and review the reported drainage Area
of 3,,48 acr
�r e
A�l
2- Please correct the bypass weir elevation from 24.4 to 24.8 on Sheet 8, Section C-C of
V� the Bypass Weir Detail.
3,/Please provide invert elevations and
��05 S heet 7 for the Vortechs Unit detail.
i 'fit?
dimension the orifice diameter and weir opening on
f 4. Please clarify in a revised Narrative whether the two future hangars and the future
-erminal building illustrated on Sheet 12 are within the Project and Drainage areas for
(AA
the proposed project. Item #1 will clarify their locations by illustration.
5. After reviewing the Drainage Area in Item #1, please report the Impervious Area in
rr ✓Section 111.6. of the application's lower table in square feet.
ql, `PloN
Please note that this request for additional information is in response to a preliminary review.
The requested information should be received by this Office prior to August 10, 2005, or the
application will be returned as incomplete. The return of a project will necessitate resubmittal of
all required items, including the application fee.
North Carolina Division of Water Quality 127 Car&al Drive Extension Phone [phone] Customer Service 1 -877-623-6748
Wilmington Regional Office Wilmington, NC 26405.3845 FAX [phone] Internet: h2o.enr.state.nc.us One
NorthCarolina
An Equal Opportunity/Affirmative Action Employer — 50% Recycled110% Post Consumer Paper Naturally

Mr. Jon W. Rosborough
August 3, 2005
Stormwater Application No. SW8 050801
If you need additional time to submit the information, please mail or fax your request for a time
extension to the Division at the address and fax number at the bottom of this letter. The
request must indicate the date by which you expect to submit the required information. The
Division is allowed 90 days from the receipt of a completed application to issue the
permit.
The construction of any impervious surfaces, other than a construction entrance under an
approved Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject
to enforcement action pursuant to NCGS 143-215.6A.
Please reference the State assigned project number on all correspondence. Any original
documents that need to be revised have been sent to the engineer or agent. All original
documents must be returned or new originals must be provided. Copies are not acceptable. If
you have any questions concerning this matter please feel free to call me at [phone].
Sincerely,
Paul T. Bartlett, P.E.
Environmental Engineer
ENBlptb: S:IWQSISTORMWATERIADDINFO120051050547
cc: Robert Williams, Talbert & Bright
Paul Bartlett
2

TALBERT& BRIGHT
August 2, 2005
Mr. Paul T. Bartlett, PE
NCDENR
127 Cardinal Drive Extension
Wilmington, NC 28405
RE: Wilmington International Airport
General Aviation Apron Expansion
All' 3-37-0084-34; TBI No. 3301-0406
Dear Paul:
ay Fee— Crjr
l'-aV1 Q,cv EPI, f D 3
Enclosed please find the Stormwater Management Permit Application package for the General
Aviation Apron Expansion project at the Wilmington International Airport. We understand that
the project will be reviewed under the express permit program. The following materials are
enclosed:
hetter from Wilmington International Airport
Application Form (original)
Application Form (copy)
Extended Dry Detention Basin Supplement
Executed Operation and Maintenance Plan
Express Processing Fee (check for $4,150.00)
Project Narrative and Drainage Calculations (2 copies)
Project Plans and Specifications (2 sets)
Please note that the total check amount is for both storrnwater and erosion and sediment control
applications. Please call me if you have any questions or need additional information.
Sincerely,
Robert Williams. El
Enclosures
RECEIVE
AUG 0 2 7005
B\yl\, DS R b _
c: Ms Julie Wilsey, Deputy Airport Director (wlent.)
fNGINHAING & PLANNING CONSUI:TANTS
WWW.TALBI;M"ANDBRIG 11T.COM
4810 SHELLEY DRIVE: WILMINGTON, NC 28405 91U63.5350 FAX [phone]
WILMINGTON, NORTH CAROLINA • CHARLOTTE. NORTH CAROLINA • RICHMOND. VIRGINIA

JI
July 2$ 2005
j NC Department of Environment and Natural Resources
u Division of Water Quality
ILM ATTN: Mr. Paul Bartlett
127 Cardinal Drive Extension
Wilmington, NC 28405
RE: Express Permit - ILM Apron Expansion
Dear Mr. Bartlett:
; R IECEI EID
7
DI5 OR l
On behalf of the Airport Authority, I would like to thank you for your support on our
ramp expansion project with the DWQ Surface Water Quality staff in Raleigh.
The Wilmington International Airport has reviewed the information provided on
July 11, 2005, about the Preliminary Evaluation Period (PEP) required for the
Vortechnics treatment technology, and we feel we must continue the express pen -nit
process with the Vortechnics unit in the project. ILM will agree to the PEP program
in order to proceed with project permitting; however, we agree only because our
contractual obligations to a tenant and the construction timeline will not allow for
further delay with permitting. We feel the PEP program as written is excessive for the
application in this specific project, but we do not have any alternatives at this time.
The airport is caught in the middle of several regulatory issues. We must be stewards
of the environment, particularly in the sensitive coastal environment; we must control
activities which may attract wildlife and pose a hazard to aviation; we must follow the
NFPA fire codes and construction guidelines for aviation facilities; and we must
maximize the use of FAA funding to accommodate the public/aviation need. The
engineers labored over the design, and we believe they presented the best design for
the site. Due to existing grades on the adjacent aircraft ramp and NFPA 409
standards, it is extremely difficult to get the ramp expansion area to drain to a grassed
swale. The ramp expansion area is the only area that will drain to the Vortechnics
device. We expect that all other development in this area will be able to be treated
with grassed swales. We respectfully request consideration to reduce the PEP testing
standards for this particular application.
Please feel free to contact me with questions or concerns on this matter.
S� c � ely,�/6�
J� ie A. Wilsey
eputy Airport Di cc r
CC: Rusty Nealis, Airport Districts Office, FAA Atlanta
Rick Barites, Division of Aviation, NCDOT
Eric Stumph, Talbert & Bright
1740AirportBoulevard • Wilmington, NC 28405 • Phone: [phone] • Fax: [phone] • www.flyilm.com

Page 1 of 26
From: "Paul Bartlett" <[e-mail]>
To: <[e-mail]>; <[e-mail]>; <[e-mail]>; <pperry@contech-
cpi.com>
Cc: "Robert Gordon" <[e-mail]>
Sent: Monday, July 11, 2005 1:49 PM
Attach: Vortech System Tech Page 1.jpg; Page 2.jpg; Page 3.jpg; Page 4.jpg; Page 5.jpg; Page 6.jpg;
Page 7.jpg; Page 8.jpg; Attachment 1.jpg; Attachment 2.jpg; Attachment 3.jpg; Attachment 4.jpg;
Sizing Criteria.jpg; TSS Removal Effeciency.jpg
Subject: General Avaiation Apron Expansion_Vortechnics System
Good morning everyone,
I discussed the proposed Vortechnics application for the Apron Expansion
with DWQ Surface Water Quality staff in Raleigh. Raleigh staff (Ken
Pickle and Bradley Bennett) don't believe a meeting there is necessary.
The Vortechnics system has been approved for permitting under PEP (refer
to attached .jpg file which will be used as a template for the permit).
Since the Vortechnics unit is being proposed as pretreatment followed by
the dry detention basin, the Vortechnics unit needs to have a TSS
removal efficiency of 70% in order to provide an overall
Vortechnics/basin TSS removal efficiency of 85%; assuming 50% efficiency
for the basin. We have flexibility in reducing monitoring requirements
after monitoring has been completed over four seasons. .
If there are any questions, please call me.
Paul T. Bartlett, P.E.
Wilmington Regional Office
DWQ, Stormwater Express Permitting
[phone] (direct)
[phone] (FAX)
Paul. [e-mail]
8/2/2005

-'.7AiU1 iA! ET&? iIGNT _ NO.�8G
IV
.- + NCKE1dR '
North Carolina Department of Environment and Natural Resources
127 Cardinal Drive, Wilmington NC 28405 [phone] FAX [phone]
Request for Express Permit Revi
FILL-IN all information below and CHECK required Per
JIFAX or email to Cameron, Wea verlQ_n cmail.n at along with a narrative andvicin,
Projects must be submitted by 9.00 A.M.of the review date, unless prior
APPLICANT Name Jon Rosborouah, Airport Director _ +
Company New Hanover County Airport Authority_
Address 1740 Airport Blvd. CitylState _ Wilminaton,INC Zip
Phone [phone] Fax [phone] Embil
I
PROJECT Name General Aviation Apron Expansion
PROJECT LOCATED IN _ Cape Fear RIVER BASIN
ENGINEER/CONSULTANT Robert C. Williams -El I
Company Talbert & Bright, Inc, i
Address 4810 Shellev Drive CitylState Wilmington NC Zip 2
Phone [phone] Fax [phone] Erb ail
❑ STREAM ORIGINATION CERTIFICATION; Stream Name
U ;
7_ IIm—
of the project loca dn.
�ments are merle. //Fitt.
County
County New Hanover
® STORMWATER ❑ Low Density ® High Densi -Detention Pond ® High Density -Other
❑ Low Density -Curb & Gutter ❑ High bensi -Infiltration ❑ Off Site
❑ COASTAL ~ �❑ Excavation & Fill �❑ Bridges & Culver ^ ❑ Structures Information _ r�
MANAGEMENT ❑ Upland Development ❑ Manna Development ❑ Urba i Waterfront
-------__.._...--------------------------- -_--------_____-------___--- - _ -__ _--___..____— �----------------------------------------
® LAND QUALITY ® Erosion and Sedimentation Control Plan withi 3.0 acres to be disturbed.
❑ WETLANDS (401) ❑ No Wetlands on Site (letter from COE) ❑Wetlands D Iineatedit JD
❑ Greater than 0.1 AC Wetlands Impacted ❑Jurisdiction I Determination has been done
❑ Less than 0.1 AC Wetlands Impacted ❑Greater than 0.5 AC Wetlands Impacted
The legislation allows additional fees, not to exceed 50% of the original Express Revie # permit application
fee, to be charged for subsequent reviews due to the insufficiency of the permit applications.
For DENR use only j�Z VuY �� J w f .
I
SUBMITTAL DATES: Fee Split for multiple permits: o4i b1 r'r e e � r
SW $ i Is y11-M7 r
CAMA $
LQS $ -S'('0 0> I 0 S?A
401
Total Fee A ount $

JUN.2E 20,0,5 '10:4 7AM TALBERT&BRIGHT
Wilutington International Air port
Wilmington, North CaroUha
General Aviation Apron'Fxp�nsion
June 2005
Proiect Overview i I
The General Aviation Apron Expansion project at the W14gton lnternatio al A
of constructing approximately 12,000 square yards of paved asphalt surface to provide additional
parking space and movement area for general aviation aircraft. The project will involve
demolition and removal of an existing general aviationi terminal building and removal of existing
concrete and asphalt pavement. The concrete pavement serves as part of the xisting apron. The
remainder of the pavement to be removed is asphalt and consists of the existing parking lot
serving the terminal building. The project area will be graded and then paved with new asphalt
pavement, Storm drain pipe and structures will also be installed to conve storm water away
from the site for treatment and storage.
The project -will result in a net increase in impe�v�ious area c
from the site through a series of inlets and pipes and conned
drains to the Airport's Extended Dry Detention Basin No.
new conveyance system were recen y perms e y�II
extended dry detention basin will provide 50% TSS remo
f 1.3 ages. St 'rin water v4ill drain
to a new cone ance system which
Both the dry detention basin and
(Permit No. 5W8 050547 . The
lal. A_V�ortecUnicsTM Storm Water
Treatment System will be used to provide minimum 35% TSS removal to rr
85% TSS removal.
Several project constraints made it necessary to use a mechanical storm wa
instead of a vegetative system (swale). The apron expansAn will tie into 4
several sides, On the other sides of the expansion future t inal. and flan
constructed. FAA grading requirements and Ni'PA fire p otection stand;
drain away from these buildings. These constraints would t allow any sly
swales or similar BMP to allow for TSS removal. Water will be required t
and then piped away from the site. Because of the relatively flat grades o:
depth required for pipe, it is impractical to pipe the water into a Swale. Bec,
a mechanical storm water treatment system is proposed. The system will
runoff from the paved apron.
The total land disturbance for the project will be 3.0 acres.1 Erosion and 5
controlled with the use of silt fence, inlet protection, and stabilized constr
areas disturbed by grading operations, with the exception o the paved area
mulched. The seeding mixture, fertilizer; and liming applications ra
specifications are based on requirements contained in thet North Carolin
Erosion Control Design Manual. The required mixture and applicati
previously used successfully at the airport.
the total required
r treatment system,
isting pavement on
it buildings will be
3s require water to
�t flow into gassed
be drained to inlets
:he airport area and
se of these reasons;
limited to treating
limentation will be
;tion entrance. All
will be seeded and
s included in the
Sedimentation and
i rates have been

IV.2S.20(15 i0:46AM T A L B E RT&BRIGHT lti'0.80 ?, 1
%0 TALBERT & BRIGHIT, INC
ENINGINEEKING & PLANNING ICONSU TANTS
FACSIMILE TRANSMITTAL
To:
Cameron Weaver
From:
i Robert V
Company:
NCDENR
Date:
1 6/28105
Fax No.
[phone]�
Total No.
of pages includi
, _
Tel No.
[phone]
TBI Ref.
t 0. 3301-04
_
Subject:
Express Review Request
Project Name:
ILM GA,
lia
cover: 5
n Expansion
IF YOU DO INOT &ECEIVE THE SPEMIED NUMER OF PAGES PLEASE CALL I--,,IhL\4EFJ[ATELY AND'X'E 4TLL MSEyt THE MIISSING DOCUMENTS,
IF ANY, OTIT�RV,15E,'XE WILL ASSUME ALL PAGES VG'>;lLE TRANSMITTED 1AF15PAC:0RILY1
[MOTES/ COMNENT5:
Cameron,
Enclosed is a request for an Express Permit Review for the Gener�l Aviation Aprol� Expansion project at the
Wilmington International Airport. As per the attached e-mail, we would like to have a prelimingry review
meeting -to -talk about the project before we submit the application. I Please call m-eif you have any
questions.
Sincerely,
Robert Williams, El
i ne information Contained in this tacsimile message is privileged and confidential information intended orlly for the use of the individual or
entity named as recipient. If the reader is not the intended recipient, be hereby notified that any 6ssemipation, distribution or copy of this
communication is strictly prohibited. if you have received this communication in error, please notify us Immediately ny telephone and return
the original message to us at the address below via the U.5. Postal Service. Thank you. I
ENGINEERING & PLA14NING CON51JUANTS
4810 Shellcy Drive V 41mington, NC ? 5405 910.763.1350 FAX 910.762,62 1
Charlotte, North Carolina • Wilmhlgron, North Carolizim • Riclumond, Virgi iia

JuN 2a 2M 0;46 i 1AL6'r-H1&bflGH1
Robert Williams
I
From: Cameron Weaver [Cameron.Weaver a,ncmail.net)
Sent: Thursday, June 23, 2005 4:26 PM
To: Robert Williams j
Subject: Re: Wilmington International Airport - GA Apron Expansi
NMI
II
WIRO Express [ameron.Weaver.v
tevlew Coversheet.. ct (410 B) Attached, please find the Request for Expri
this out and
attach the requested documents. Once I've received that, I will be ablE
to schedule a pre --application meeting for this project; schedules are
pretty full next week, so I'll have to let you know about the date after
I've distributed your request.
Cameron
Robert Williams wrote:
> Dear Mr. Weaver,
>
> We are working on a design for expansion of the General Aviation 2
> at the Wilmington Intemational Airport and have some questions
> regarding stormwater treatment. We would like to pursue express
> permitting for Stormwater and Erosion & Sedimentation and would I
> to have a preliminary review meeting to discuss these questions ani
> get NCDENR's comments and guidance on the project before we si
> for review. We would like to meet with you sometime�next week (Jul
> to July 1) to discuss this project. Please let me know )f this is
> possible and a time that would be convenient.
> Robert Williams, El
> TALBERT & BRIGHT, INC.
> 4810 Shelley Drive
>
> Wilmington, NC 28405
>
> [phone] office
> [phone] fax
1
Project
s Review. Fill
ro n
to
bmit it
;e 27

-
+7 v ` �'' � : �! ` t w �r� <t v 1`'r- ��r tc r. '_ 5L� �!, � `•` ��� � � �'i•
.3i - 2,s ✓c f ..,d'r ci' r •YR C.d •}. 4 r#�k \y
, � 1 1• {,�,slti c F'. - _ S !zO
:z* 'r ��� � r' - T-l'•'..• �, i� -,;i •'a -ra `�, r Lt��_f;�f f r
�;'�,.J.'J' r � �t � ����a"Xt rlw �: $.,r y. { .�i e�„ -h: } a r - i•r �.
f
r �.�l4—! � � ]• ! � ra -FSt� t�'� 11r.r'.i, 1 !r •,r �1.. -'S � + _-
!{'r Pi- . -ir f - �Z VI..
. 5•: 1- _ r � •.!
�'- � `� �•! r � t ti!' '•!1 � �ll1r � -� � FFF r.' t� � •`,r � �.,1 i � \ f. _ •�F _
�.r? IIf L yl -u- f i Y.r t�. �P♦
�`5L••F;-, r+,r{ •y L. -
„ s'?� .� •� i '+.�'Ny !k � t 'GF• x•t.; �; + a[ � �-S � =7k �'��.;��: %!.'�ti� t .J . 1it'a �
IEi� r- 1yf .• i � '�. -
L i
lw �
ti It Y �• ��- !+f v �' •: .
.F 1. -!!'� -R?. • S� <'•`• � '�-�-�, •ems.•"'
- ls.. y� '' - s ' �,r% a 7a•�' -ti"¢ -T"'7- ,;
i! � r r!r \ r t 3 {• •a ! !
'� - ..its iA _ :.'•yt'Y 4': 1s `I�' x'r� ,.`jlr.;• ;s = $ --•� -- -"j -
"r��.• ^er tyjJ -`.�� 1�, :ryYF 7 !:- s r!�_ — ��11.• r%• ��}'r it � 1�aLL�
MEMO
lot
IV Q
! v 'x • '�• i�;t �•• J-3� !� t- � 4 rit� --s ._ � � _ fit.-� �.''F .►-
�r: h +s ',F " � � 3 > 1 � n, • `41t,'� }r, �• i� __IOW
r. Ari .�' 1 1 / _ 3 i'•:+yr i+;n:, S r - i .!- Y C�'
�+ s .77: - } r + ! a � 5,= d , � .� n,. 'A(r�{• r• .:j.r • p �r� � Y•IJ�
�:•: �i't3'�. �r i � a+ �.+ ',� � J'. .f .:a�j� J� i t !, yf 4`.�1 i J� 4�`•'�� % ,.`I:'Sii .�.. .� _ .,� ..' - •' • d??;
•5;:� u; :r _ �:' .r. S>'r• i r .t„J .. -•�v++,r, y• <,F tix:: <�..A%x•, . r=..f ,c,eyr�-,•. r ,L ell�a U�_�i=: �_.1%� r -,fir •a 4�?:
•�1: ' ! IY�n f s;.l'• t t:."�� � t ya i li.i S `"�. T...C:xarfi�ti\ti s.i 4- '�" •. r.�r : r+ ` � i •. E ! J