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Post -Construction Stormwater Management
Permit No. SW8 050547
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENTAL QUALITY
DIVISION OF ENERGY, MINERAL AND LAND RESOURCES
POST -CONSTRUCTION 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
New Hanover County Airport Authority
Wilmington International Airport Extended Dry Detention Basins (EDDB)
1740 Airport Boulevard, Wilmington, New Hanover County
FOR THE
construction, operation and maintenance of three (3) extended dry detention basin ("stormwater
control measures" or "SCM") in compliance with the provisions of 15A NCAC 2H .1000 (1995 Rules)
as amended on January 1, 2017 (2017 Rules) (collectively, the "stol7nwaterruiesl and as outlined in
the application, approved stormwater management plans, supplement, calculations, operation and
maintenance agreement, recorded documents, specifications, and other supporting data (the
"approved plans and specifications") as attached and/or on file with and approved by the Division of
Energy, Mineral and Land Resources (the "Division" or "DEMLR"). The project shall be constructed,
operated and maintained in accordance with these approved plans and specifications. The approved
plans and specifications are incorporated by reference and are enforceable part of this permit.
This permit shall be effective from the date of issuance until June 15, 2027 and shall be subject to the
following specified conditions and limitations. The permit issued shall continue in force and effect until
the permittee files a request with the Division for a permit modification, transfer, renewal, or
rescission; however, these actions do not stay any condition. 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 for cause as allowed by the laws, rules, and regulations contained in Title 15A
NCAC 2H.1000 and NCGS 143-215.1 et.al.
I. DESIGN STANDARDS
1. The drainage area identified as Phase I&II is subject to the 1995 Rules and as clarified in the
1995 specific conditions listed herein. The drainage areas identified as Phase IIIA, Phase 11113
and Phase IIIC are subject to the 1995 Rules and the 2017 Rules and as clarified in the 2017
Rules specific conditions listed herein.
2. This project and SCMs have been approved based on the "Wilmington International Airport
Stormwater Master Plan" document approved on November 24, 2004 as a variation to the
stormwater rules and in accordance with G.S. 143-214.7(c3). All future major modifications to
this permit must either meet the 2004 "Wilmington International Airport Stormwater Master
Plan" in its entirety, meet the most current set of stormwater rules, or provide technical
justification that the proposed modification is providing equal or better control and equal or
better protection of water of the State as a variation under the current set of stormwater rules.
Approval of such variations that do not meet all of the requirements is done on a case -by -case
basis.
3. FAA requirements prohibit standing water (i.e., permanent pools) and stipulate that the design
storm must be fully drained within 48 hours. This is supported by G.S. 143-214.7(c3) where
the Division does not require the use of an SCM with standing water. The approved SCM
design for the 3 extended dry detention basins includes a low flow device but does not include
a permanent pool at the low flow outlet or sediment storage.
Page 1 of 6

Post -Construction Stormwater Management
Permit No. SW8 050547
4. The approved "Wilmington International Airport Stormwater Master Plan" document is not
intended to limit or restrict the airport or its current or prospective tenants from pursuing
alternative or modified stormwater management solutions in various locations than those listed
in the document itself. Since the approval of the "Wilmington International Airport Stormwater
Master Plan" document, other stormwater control measure (SCM) options that do not contain
areas of standing water have been developed and should be evaluated for future projects.
5. This permit is effective only with respect to the nature and volume of stormwater described in
the application and other supporting data. The maximum amount of built -upon area (BUA)
allowed for the entire project is 9,304,059 square feet.
6. The three (3) SCMs identified as "Phase I and 11" Extended Dry Detention Basin, Phase IIIA
Extended Dry Detention Basin and Phase IIIB Extended Dry Detention Basin have been
designed to handle the runoff from 8,520,835 square feet, 116,598 square feet, and 367,596
square feet of BUA, respectively, within the delineated drainage areas. The BUA for future
development within the drainage areas to the SCMs identifies as "Phase I and 11" Extended
Dry Detention Basin, Phase IIIA Extended Dry Detention Basin and Phase IIIB Extended Dry
Detention Basin is limited to 2,057,505 square feet, 48,788 square feet, and 264,031 square
feet, respectively.
7. Where an individual project within the drainage area is being leased or sold, the stormwater
collection system for that project must be located in either dedicated common areas or
easements and the final plats will be recorded showing all such required easements.
8. The drainage areas for the on -site stormwater systems will be limited to the amounts of built -
upon area indicated in this permit and the approved plans and specifications. The runoff from
all built -upon area within the permitted drainage areas of this project must be directed into the
permitted stormwater control measures.
9. (2017 Rules) The peak flow from the 10-year storm event shall not cause erosion downslope
of the discharge point.
10. (2017 Rules) A 50-foot wide vegetative setback must be provided and maintained in grass or
other vegetation adjacent to all surface waters as shown on the approved plans. The setback
is measured horizontally from the normal pool elevation of impounded structures, from the top
of bank of each side of streams or rivers, and from the mean high waterline of tidal waters,
perpendicular to the shoreline.
11. The portion of the existing airport previously included in the drainage area of the permitted dry
detention basin that is being removed, must be submitted in a future permit application as a
modification or under G.S. 143-214.7(c4).
12. (1995 Rules) The following design criteria have been provided and must be maintained in the
"Phase I and II" Extended Dry Detention Basin.
Phase I & II
a. Drainage Area, acres: 287.63
Onsite, ft2: 12,529,107
Offsite, ft2: 0
b. Total Impervious Surfaces, ft2: 8,520,835
C. Design Storm, inches: 4,552,087 @1"
3,968,748 @1.5-
d. Basin Bottom Elevation, feet: 7.0
e. TSS removal efficiency: 50%
f. Storage Elevation, FMSL: 13.0
g. Storage Surface Area, ft2: 506,082
h. Permitted Detention Volume, ft3: 1,058,112
i. Seasonal High Water Table, FMSL: 6.0
j. Controlling Orifice: 12.0" 0
k. Drawdown Time for 12.0" fd orifice, hours: 57
I. Receiving Stream/River Basin: Smith Creek / Cape Fear
M. Stream Index Number: 18-74-63
n. Classification of Water Body: C;Sw
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Post -Construction Stormwater Management
Permit No. SW8 050547
13. (2017 Rules) The SCMs identified as Phase IIIA Extended Dry Detention Basin and Phase IIIB
Extended Dry Detention are permitted based on the design criteria presented in the sealed,
signed and dated supplements, the sealed and signed "Technical Justification" document
dated April 13, 2021 justifying the variations from the Wilmington International Airport
Stormwater Master Plans well as the 2017 minimum design criteria, and as shown in the
approved plans and specifications. These SCMs must be provided and maintained at the
design condition. The approved supplements are incorporated by reference into this permit.
14. (2017 Rules) If the SCMs identified as Phase IIIA Extended Dry Detention Basin and Phase
IIIB Extended Dry Detention are found to not meet the approved design criteria, a modification
must be submitted to either meet the requirements or propose another variation from the rules.
This is based on a case -by -case decision and should not be used as a precedent for future
permitting actions.
15_ Tributary projects outside of the drainage area of the previously approved "for -credit" grassed
swales, but inside the drainage area of the approved SCMs, must provide an additional BMP
with a sufficient TSS removal efficiency such that the total TSS removal, including the
extended dry detention basin, is at least 85%.
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. 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.
3. The facilities shall be constructed, operated, and maintained in accordance with the provisions
of this permit, the approved plans and specifications, and the supporting documents attached
to this permit and on file with the Division.
4. The permittee is responsible for verifying that the proposed built -upon area for the entire
project does not exceed the maximum allowed by this permit.
5_ Upon completion of the project, the permittee shall determine if the project is in compliance
with the approved plans and take the necessary following actions:
a. If the permittee determines that the project is in compliance with the approved plans,
then within 45 days of completion, the permittee shall submit to the Division one hard
copy and one electronic copy of the following:
i. The completed and signed Designer's Certification provided in Attachment A
noting any deviations from the approved plans and specifications. Deviations
may require approval from the Division;
ii. A copy of the recorded operation and maintenance agreement;
iii. Unless already provided, a copy of the recorded deed restrictions and
protective covenants; and
iv. A copy of the recorded plat delineating the public rights -of -way, dedicated
common areas and/or permanent recorded easements, when applicable.
b. If the permittee determines that the project is not in compliance with the approved plans,
the permittee shall submit an application to modify the permit within 30 days of
completion of the project or provide a plan of action, with a timeline, to bring the site into
compliance.
Page 3 of 6

Post -Construction Stormwater Management
Permit No. SW8 050547
6. The permittee shall at all times provide the operation and maintenance necessary to assure
the permitted stormwater system functions at the design condition. 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 slopes and the vegetated filter.
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, flow spreader, catch
basins and piping.
g. Access to the outlet structure must be available at all times.
7. Records of maintenance activities must be kept and made available upon request to
authorized personnel of DEMLR. The records will indicate the date, activity, name of person
performing the work and what actions were taken.
8. (2017 Rules) The operation and maintenance agreement must be recorded with the Office of
the Register of Deeds.
9. (2017 Rules) The final plats for the project must be recorded with the Office of the Register of
Deeds. The recorded plat must reference the Operation and Maintenance Agreement and
must also show all public rights -of -way, dedicated common areas, and/or permanent drainage
easements, in accordance with the approved plans.
10. Access to the permitted stormwater facilities shall be maintained via appropriate easements
(as required) at all times.
11. No person or entity, including the permittee, shall alter any component shown in the approved
plans and specifications. Prior to the construction of any modification to the approved plans,
the permittee shall submit to the Director, and shall have received approval for modified plans,
specifications, and calculations including, but not limited to, those listed below. For changes to
the project or SCM that impact the certifications, a new or updated certification(s), as
applicable, will be required and a copy must be submitted to the appropriate DEQ regional
office upon completion of the modification.
a. Any modification to the approved plans and specifications, regardless of size including
the SCM(s), BUA, details, etc.
b. Redesign or addition to the approved amount of BUA or to the drainage area.
C. Further development, subdivision, acquisition, lease or sale of any, all or part of the
project and/or property area as reported in the approved plans and specifications.
d. Altering, modifying, removing, relocating, redirecting, regrading, or resizing of any
component of the approved SCM(s), the stormwater collection system and/or
vegetative conveyance shown on the approved plan.
e. The construction of any allocated future BUA.
f. The construction of any permeable pavement, #57 stone area, public trails, or
landscaping material to be considered a permeable surface that were not included in
the approved plans and specifications.
g. Other modifications as determined by the Director.
12. 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.
Ili. GENERAL CONDITIONS
CORRECTIVE ACTIONS REQUIRED. If the facilities fail to perform satisfactorily, the
permittee shall take immediate corrective actions. This includes actions required by this
Division and the stormwater rules such as the construction of additional or replacement on -site
stormwater systems. These additional or replacement measures shall receive a permit from
the Division prior to construction.
Page 4of6

Post -Construction Stormwater Management
Permit No. SW8 050547
2. PERMIT RENEWAL. A permit renewal request must be submitted at least 180 days prior to
the expiration date of this permit. The renewal request must include the appropriate
application, documentation and the processing fee as outlined in Title 15A NCAC
02H.1045(3).
3. CHANGES TO THE PROJECT NAME, PERMITTEE NAME OR CONTACT INFORMATION.
The permittee shall submit a completed Permit Information Update Application Form to the
Division within 30 days to making any one of these changes.
4. TRANSFER. This permit is not transferable to any person or entity except after notice to and
approval by the Director. Neither the sale of the project and/or property, in whole or in part, nor
the conveyance of common area to a third party constitutes an approved transfer of the permit.
a. TRANSFER REQUEST. The transfer request must include the appropriate application,
documentation and the processing fee as outlined in 15A NCAC 02H.1045(2). This
request must be submitted within 90 days of the permit holder meeting one or more of the
following:
i. A natural person who is deceased;
ii. A partnership, limited liability corporation, corporation, or any other business
association that has been dissolved;
iii. A person or entity who has been lawfully and finally divested of title to the property
on which the permitted activity is occurring or will occur through foreclosure,
bankruptcy, or other legal proceeding.
iv. A person or entity who has sold the property, in whole or in part, on which the
permitted activity is occurring or will occur.
b. TRANSFER INSPECTION. Prior to transfer of the permit, a file review and site inspection
will be conducted by Division personnel to ensure the permit conditions have been met and
that the project and the on -site stormwater system complies with the permit conditions.
Records of maintenance activities performed to date may be requested. Projects not in
compliance with the permit will not be transferred until all permit and/or general statute
conditions are met.
5. COMPLIANCE. The permittee is responsible for compliance with the terms and conditions of
this permit until the Division approves the transfer request.
a. APPROVED PLANS AND SPECIFICATIONS. A copy of this permit, approved plans,
application, supplement, operation and maintenance agreement, all applicable
recorded documents, and specifications shall be maintained on file by the permittee at
all times.
b. DIVISION ACCESS. The permittee grants Division Staff permission to enter the
property during normal business hours to inspect all components of the permitted
project.
c. ENFORCEMENT. Any individual or entity found to be in noncompliance with the
provisions of a stormwater management permit or the requirements of the stormwater
rules is subject to enforcement procedures as set forth in NCGS 143 Article 21.
d. ANNUAL CERTIFICATION. The permittee shall electronically submit to the Division an
annual certification completed by either the permittee or their designee confirming the
projects conformance with permit conditions
e. OBTAINING COMPLIANCE. 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 modified plans and certification in writing to the Director that the
changes have been made.
Page 5 of 6

Post -Construction Stormwater Management
Permit No. SW8 050547
OTHER PERMITS. The issuance of this permit does not preclude the permittee from
complying with and obtaining any other permits or approvals that are required for this
development to take place, as required by any statutes, rules, regulations, or
ordinances, which may be imposed by any other Local, State or Federal government
agency having jurisdiction. Any activities undertaken at this site that cause a water
quality violation or undertaken prior to receipt of the necessary permits or approvals to
do so are considered violations of NCGS 143-215.1, and subject to enforcement
procedures pursuant to NCGS 143-215.6.
Permit modified, updated and reissued this the 6th day of April 2022.
NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION
rAZL'-_0 u
Brian Wrenrl,irec r
Division of Energy, Mineral and Land Resources
By Authority of the Environmental Management Commission
Permit No. SW8 050547
Page 6 of 6

Post -Construction Stormwater Management
Permit No. SW8 050547
Wilmington International Airport
Stormwater Permit No. SW8 050547
New Hanover County
Attachment A
Designer's Certification
I, , as a duly registered in the State of North
Carolina, having been authorized to observe (periodically/ weekly/ full time) the construction of the
project,
(Project)
for (Project Owner) hereby state that, to the best of my
abilities, due care and diligence was used in the observation of the project construction such that the
construction was observed to be built within substantial compliance and intent of the approved plans
and specifications.
The checklist of items on page 2 of this form is included in the Certification.
Noted deviations from approved plans and specification:
Signature
Registration Number
Date
SEAL
Page 1 of 2

Post -Construction Stormwater Management
Permit No. SW8 050547
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 drainage within the permitted contributing drainage area 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. A 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 device is correctly located and sized per the approved plans.
13. All required design depths are provided.
14. All required parts of the system are provided, such as pretreatment devices, outlet
structure and/or forebay.
15. The required system dimensions are provided per the approved plans.
16. The maximum drainage area and/or built -upon area have not been exceeded for the
"Phase I & II" condition.
cc: NCDEQ-DEMLR Regional Office
New Hanover County Building Inspections
Page 2 of 2

Post -Construction Stormwater Management
Permit No. SW8 050547
Attachment C - Permitting History
Wilmington International Airport EDDB
Permit No. SW8 050547
Approval
PermittBBIMS
I
I__
Description of the Changes- T- E
Date
Action
Version
This original issuance approved the 150 acre area
pocket of high density Phase I, in accordance with
6/15/2005
Original
1.0
SW8 040836, to be treated in an extended dry
Approval
detention basin (EDDB) #1 designed to handle the
runoff from 4,247,100 square feet of impervious
area.
Approved the modification of the permit to include
Phase II, which brought the total project area to
10/28/2009
Modification
1.1
264 acres and increased the size of the EDDB # 1 to
handle a total of 8,468,064 square feet of
impervious area.
Approved the modification to include Phase III,
which brought the total project area to 321.35 acres
and increased the size of the EDDB # 1 to handle a
10/26/2011
Modification
1.2
total of 8,468,064 square feet of impervious area.
This permit also took into account the impervious
area for SW8 060326 and SW8 060515, which
both drain to EDDB #1 and were permitted as
Offsite permits to SW8 050547.
Approved the modification to the overall drainage
area to 3 22.3 8 acres and the increased size of
EDDB # 1 to handle a total of 9,751,185 square feet
11/29/2012
Modification
1.3
of impervious area. This modification included the
addition of two grassed pre-treatment swales. This
issuance left 3,177,214 square feet of Future
allocation for the Phase I & II area.
Approved the reallocation of 205,202 square feet of
Plan
Future allocation for the development of the Rental
2/8/2013
Revision
1.4
Car Facility within the Phase I & II drainage area.
This issuance left 2,972,012 square feet of Future
allocation.
Approved the reallocation of 32,453 square feet of
Plan
Future allocation for the expansion of the North
8/4/2015
Revision
1.5
General Aviation Apron draining to EDDB #1.
This issuance left 2,939,559 square feet of Future
allocation for the Phase I & II area.
Page 1 of 3

Post -Construction Stormwater Management
Permit No. SW8 050547
Approved the reallocation of a total of 129,082
square feet of future allocation, 62,570 square feet
Plan
for the Business Park access road and 66,512
9/9/2015
Revision
1.6
square feet for Lot 9 of the Business Park, both
draining to EDDB #1. This issuance left 2,810,477
square feet of Future allocation for the Phase I & Il
area.
Approved the reallocation of 122,922 square feet of
future allocation for the North General Aviation
Hangar Taxiline and Corporate Hanger Complex.
6/29/2016
Plan
1
This also took into account the 24,190 square feet
Revision
'7
of impervious area allocated to SW8 150723,
which drains to EDDB # 1 and is permitted as an
Offsite permit to SW8 050547. This issuance left
2,663,295 square feet of Future allocation.
Approved the reallocation of 75,596 square feet of
8/22/2017
Plan
1'8
future allocation for the Avis Car Rental Facility
Revision
draining to EDDB #1. This issuance left 2,587,699
square feet of Future allocation.
Approved the reallocation of 29,337 square feet of
4/18/2018
Minor
1.9
future allocation for the Social Bark Kennel
Modification
draining to EDDB #1. This issuance left 2,558,362
square feet of Future allocation.
Approved the reallocation of 110,358 square feet of
10/5/2018
Minor
2.0
future allocation for the FBO #2 project draining to
Modification
EDDB #1. "Ibis issuance left 2,448,004 square feet
of Future allocation.
10/3/2019
Renewal
3.0
This issuance renewed Permit No. SW8 050547
until June 15, 2027.
Approved the reallocation of 224,194 square feet of
future allocation for the Air Carrier Apron
Expansion draining to EDDB #1. This modification
Major
also adds Pre-treatment Swale #3 as pretreatment
10/6/2020
Modification
3.1
for EDDB #1. The submittal also included 9,268
square feet of impervious area that meets NCGS
143-214.7(c4) that does not drain to EDDB #l.
This issuance left 2,223,812 square feet of Future
allocation for the Phase I & U area.
Page 2 of 3

Post -Construction Stormwater Management
Permit No. SW8 050547
This issuance replaces the originally approved
Phase III expansion (and "Overall" condition) of
Extended Dry Detention Basin (EDDB) #1 with
two new EDDB's. EDDB # 1 remains unmodified at
the Phase I&II condition. The two new EDDB's,
identified as Phase IIIA and Phase IHB on the
plans, are permitted as a variation to the rules based
4/20/2021 Major 3.2 on the 2004 "Wilmington International Airport
Modification Stormwater Master Plan" document, signed and
sealed "Technical Justification " document dated
April 13, 2021, and supplements as shown in the
approved plans and specifications. The Phase IIIA
EDDB has been designed to handle the runoff from
116,598 square feet of BUA and he Phase IIIB
EDDB has been designed to handle the runoff from
367,596 square feet of BUA.
This issuance approved the reallocation of 48,658
Minor square feet of future BUA within the EDDB # 1
6/10/2021 3.3 drainage area for the construction of the Aero
Modification Center Wilmington project. This issuance left a
total of 2,175,154 square feet of future allocation.
This issuance approved the reallocation of 117,649
square feet of future BUA within the EDDB # 1
4/6/2022 Minor 3.4 drainage area for the Air Carrier Apron Expansion.
Modification This issuance left a total of 2,057,505 square feet of
future allocation within the EDDB # 1 drainage
area.
Page 3 of 3

Permit Number: S WB (37tpS-i ( -4
(to be provided by DWQ)
Drainage Area Number: rr-41 wsC M:A
Dry Extended Detention Basin
Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BUT 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 BUT.
The dry extended detention basin system is defined as the dry detention basin, outlet
structure, 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:
- The drainage area will be managed to reduce the sediment load to the dry
extended detention basin.
- Immediately after the dry extended detention basin is established, the vegetation
will be watered twice weekly if needed until the plants become established
(commonly six weeks).
- No portion of the dry extended detention pond will be fertilized after the first
initial fertilization that is required to establish the vegetation-
- I will maintain the vegetation in and around the basin at a height of
approximately six inches.
- Once a year, a dam safety expert will inspect the embankment.
After the dry extended detention basin is established, it will be inspected once a quarter
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 will be kept in a known set
location and will 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 dry
Areas of bare soil and/or
Regrade the soil if necessary to
extended detention
erosive gullies have formed.
remove the gully, and then plant a
basin
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application
Form SW401-Dry Detention O&M-Rev.3 Page 1 of 4

BMP element:
Potentialproblem:
How I will remediate theproblem:
The inlet device: pipe or
The pipe is clogged (if
Unclog the pipe. Dispose of the
swale
applicable).
sediment off -site.
The pipe is cracked or
Replace the pipe.
otherwise damaged (if
applicable).
Erosion is occurring in the
Regrade the swale if necessary to
swale (if applicable).
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
Search for the source of the
and reduced the depth to 75 %
sediment and remedy the problem if
of the original design depth
possible. Remove the sediment and
(see diagram below).
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Erosion has occurred or
Provide additional erosion
riprap is displaced.
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 pesticides are used, wipe
them on the plants rather than
spraying.
The main treatment area
Sediment has accumulated
Search for the source of the
and reduced the depth to 75%
sediment and remedy the problem if
of the original design depth
possible. Remove the sediment and
(see diagram below).
dispose of it in a location where it
will not cause impacts to streams or
the BMP. Revegetate disturbed
areas immediately with sod
(preferred) or seed protected with
securely staked erosion mat.
Water is standing more than
Check outlet structure for clogging.
5 days after a storm event.
If it is a design issue, consult an
appropriate rofessional.
Weeds and noxious plants are
Remove the plants by hand or by
growing in the main
wiping them with pesticide (do not
treatment area.
spray).
Form SW401-Dry Detention O&M-Rev.3 Page 2 of 4

BMP element:
Potentialproblem:
How I will remediate theproblem:
The embankment
Shrubs or trees have started
Remove shrubs or trees
to grow on the embankment.
immediately.
Grass cover is unhealthy or
Restore the health of the grass cover
eroding,
- consult a professional if necessary.
Signs of seepage on the
Consult a professional.
downstream face.
Evidence of muskrat or
Use traps to remove muskrats and
beaver activity is present.
consult a professional to remove
beavers.
An annual inspection by an
Make all needed repairs.
appropriate professional
shows that the embankment
needs repair.
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 NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit at 919-
outlet.
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 basin depth reads 15.50 feet in the main pond, the sediment shall be removed.
When the basin depth reads NA feet in the forebay, the sediment shall be removed.
Sediment Removal
Bottom
BASIN DIAGRAM
(fill in the blanks)
NA----------- T porar�
olume
NA 25%
Sediment
Storage
FOREBAY
Temporary Pool.Flevation 17.7..6'
Pool emporar
\------Sediment Removal Elevation 15.50---- .;- Volume
tom Elevation 14.50•z, 1 25%
MAIN POND
Form SW401-Dry Detention O&M-Rev.3 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:CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
BMP drainage area numberTHASE 3A
Print name:GRANSEUR DICK
Title:FACILITIES DIRECTOR - NEW HANOVER COUNTY AIRPORT AUTHORITY
Address:1740 AIRPORT BLVD, WILMINGTON, NC 28405
Signature:
Date: 9�9 jz® 2-
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.
I, �()R 01. 1)&V6 , a Notary Public for the State of
N& fk CCtrp 1 let& , County of NeL4) 4AhoU(,r , do hereby certify that
l lYaMe.t .r1),ck, personally appeared before me this q
day of / , 2020 , and acknowledge the due execution of the
forgoing dry detention basin maintenance requirements. Witness my hand and official
seal, M
Q-°sE M oq
s
NOTARY
z PUBLIC 2
VER C09
SEAL
My commission expiresI y
Form SW401-Dry Detention O&M-Rev.3 Page 4 of 4

Permit Number: 6tsOrzFq-T
(to be provided by DWQ)
Drainage Area Number:
Dry Extended Detention Basin
Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BUT 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 BUT.
The dry extended detention basin system is defined as the dry detention basin, outlet
structure, 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:
- The drainage area will be managed to reduce the sediment load to the dry
extended detention basin.
- Immediately after the dry extended detention basin is established, the vegetation
will be watered twice weekly if needed until the plants become established
(commonly six weeks).
- No portion of the dry extended detention pond will be fertilized after the first
initial fertilization that is required to establish the vegetation.
- I will maintain the vegetation in and around the basin at a height of
approximately six inches.
-- Once a year, a dam safety expert will inspect the embankment.
After the dry extended detention basin is established, it will be inspected once a quarter
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 will be kept in a known set
location and will 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 dry
Areas of bare soil and/or
Regrade the soil if necessary to
extended detention
erosive gullies have formed.
remove the gully, and then plant a
basin
ground cover and water until it is
established. Provide lime and a
one-time fertilizer application
Form SW401-Dry Detention O&M-Rev.3
Page 1 of 4

BMP element:
Potentialproblem:
How I will remediate theproblem:
The inlet device: pipe or
The pipe is clogged (if
Unclog the pipe. Dispose of the
Swale
applicable).
sediment off -site.
The pipe is cracked or
Replace the pipe.
otherwise damaged (if
applicable).
Erosion is occurring in the
Regrade the swale if necessary to
swale (if applicable).
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
Search for the source of the
and reduced the depth to 75%
sediment and remedy the problem if
of the original design depth
possible. Remove the sediment and
(see diagram below).
dispose of it in a location where it
will not cause impacts to streams or
the BMP.
Erosion has occurred or
Provide additional erosion
riprap is displaced.
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 pesticides are used, wipe
them on the plants rather than
spraying.
The main treatment area
Sediment has accumulated
Search for the source of the
and reduced the depth to 75%
sediment and remedy the problem if
of the original design depth
possible. Remove the sediment and
(see diagram below).
dispose of it in a location where it
will not cause impacts to streams or
the BMP. Revegetate disturbed
areas immediately with sod
(preferred) or seed protected with
securely staked erosion mat.
Water is standing more than
Check outlet structure for clogging.
5 days after a storm event.
If it is a design issue, consult an
appropriate rofessional.
Weeds and noxious plants are
Remove the plants by hand or by
growing in the main
wiping them with pesticide (do not
treatment area.
I spray) -
Form SW401-Dry Detention O&M-Rev.3 Page 2 of 4

BMP element:
Potentialproblem:
How I will remediate the problem:
The embankment
Shrubs or trees have started
Remove shrubs or trees
to ow on the embankment.
immediately.
Grass cover is unhealthy or
Restore the health of the grass cover
eroding.
- consult a professional if necessary.
Signs of seepage on the
Consult a professional.
downstream face.
Evidence of muskrat or
Use traps to remove muskrats and
beaver activity is present.
consult a professional to remove
beavers.
An annual inspection by an
Make all needed repairs.
appropriate professional
shows that the embankment
needs repair.
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 NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit at 919-
outlet.
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 basin depth reads 15.00 feet in the main pond, the sediment shall be removed.
When the basin depth reads NA feet in the forebay, the sediment shall be removed.
Sediment Removal
Bottom
BASIN DIAGRAM
ill in the hlanks)
Q Temporary Pool Elevation.16,90
NA T por Pool
-------------- -- olume Sediment Removal Elevation 15.00',
NA25%--------------.-------------------=..---------=
Sediment Bottom Elevation 13.25
Storage
FOREBAY MAINYOND
Form SW401-Dry Detention O&M-Rev.3 Page 3 of 4
Volum
25%

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:CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
BMP drainage area number:PHASE 3B
Print name:GRANSEUR DICK
Title:FACILITIES DIRECTOR - NEW HANOVER COUNTY AIRPORT AUTHORITY
Address:1740 AIRPORT BLVD WILMINGTON, NC 28405
Signature: C. CL-0
01
Date: VOL 0 2 O
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.
I, ?105e- Iy , • 1JQ �/�^S , a Notary Public for the State of
N &-M "I I n.- , County of 1kx,3 F r�o r , do hereby certify that
�4 6Lr152u.r D1Gk.� personally appeared before me this -7
day of Se64fAJQeC r a20 , and acknowledge the due execution of the
forgoing dry detention basin maintenance requirements. Witness my hand and official
seal, P49+ M . I s
NOTARY
m PUBLIC z
co���
DER .V
SEAL
My commission expires Zy
Form SW401-Dry Detention O&M-Rev.3 Page 4 Of 4

Permit Name: SL01 1 ors n
(to be provided by DWQ)
Drainage Area Number'
�[T A
Grassed Swale Operation and Maintenance Agreement
I will keep a maintenance record on this BNT. 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 BW.
Important maintenance procedures:
- The drainage area of the grassed swale will be carefully managed to reduce the
sediment load to the grassed Swale.
- After the first-time fertilization to establish the grass in the swale, fertilizer will
not be applied to the grassed swale.
The grassed swale will be inspected once a quarter. Records of operation and
maintenance will be kept in a known set location and will 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 length of the
swale
Trash/debris is present.
Remove the trash/debris.
Areas of bare soil and/or
Regrade the soil if necessary to
erosive gullies have formed.
remove the gully, and then re -sod
(or plant with other appropriate
species) and water until established.
Provide lime and a one-time
fertilizer application.
Sediment covers the grass at
the bottom of the swale.
Remove sediment and dispose in an
area that will not impact streams or
BMPs. ;Re -sod ii necessary.
Vegetation is too short or too
Maintain vegetation at a height of
long
approximatelyapproxirnately six inches. ,
The receiving water
Erosion or other signs of
Contact the NC Division of Water
damage have occurred at the
Quality 401 Oversight Unit -at 919-
outlet.
733-1786.
Form SW401-Grassed Swale O&M-Rev.3 Page 1 of 2

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:CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
BMP drainage area numberTHASE 3A
Print name:GRANSEUR DICK
Title:FACILITIES DIRECTOR - NEW HANOVER COUNTY AIRPORT AUTHORITY
Address:1740 AIRPORT BLVD WILMINGTON, NC 28405
Signature:
Date: V 91Zd Z
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.
I, PDV_ M ,16ciu'O , a Notary Public for the State of
t_ tN+J, "I I VW,�. , County of WtZ 44&A,o" ! , do hereby certify that
%•wnr _D I cle— personally appeared before me this
day of 5 , c)COO, and acknowledge the due execution of the
forgoing grassed Swale maintenance requirements. Witness my hand nd official seal,
rA* M. 1.aAn��
z NOTARY
PUBLIC 2
CLIER CC119
SEAL
My commission expires
Form SW401-Grassed Swale O&M-Rev.3 Page 2 of 2

Permit Name: $Wg p�m —fir,
(to be provided by DWQ)
Drainage Area Number: fljwN, 11r3
Grassed Swale Operation and Maintenance Agreement
I will keep a maintenance record on this BMP. This maintenance record will be kept in a
log in a known set location. Any deficient BUT 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.
Important maintenance procedures:
— The drainage area of the grassed swale will be carefully managed to reduce the
sediment load to the grassed swale.
— After the first-time fertilization to establish the grass in the swale, fertilizer will
not be applied to the grassed swale.
The grassed swale will be inspected once a quarter. Records of operation and
maintenance will be kept in a known set location and will be available upon request.
Inspection activities shall be performed as follows. Any problems that are found shall
be repaired immediately.
BMP element:
Potential problenc
How I will remediate theproblem:
The entire length of the
Trash/debris is present.
Remove the trash/debris.
swale
Areas of bare soil and/or
Regrade the soil if necessary to
erosive gullies have formed.
remove the gully, and then re -sod
(or plant with other appropriate
species) and water until established.
Provide lime and a one-time
fertilizer application.
Sediment covers the grass at
the bottom of the swale.
Remove sediment and dispose in an
area that will not impact streams or
BMPs.. Re=sod.if necessary.
Vegetation is too short or too
Maintain vegetation at a height of
long.
approximately six inches. -
The receiving water
Erosion or other signs of
Contact the NC Division of Water
damage have occurred at the
outlet.
Quality 401 Oversight Unit at 919-
733-1786.
Form SW401-Grassed Swale O&M-Rev.3 Page 1 of 2

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:CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
BMP drainage area number:PHASE 3B
Print name:GRANSEUR DICK
Title:FACILITIES DIRECTOR - NEW HANOVER COUNTY AIRPORT AUTHORITY
Address:1740 AIRPORT BLVD WILMINGTON, NC 28405
Phone: [phone]
Signature
Date:
IX Zd20
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.
4, a Notary Public for the State of
kly% ,C&-rol 1y-.k , County of kk!4) J-e-- , do hereby certify that
CWrLN_f4ttA, f- —b1ek, personally appeared before me this
day of �--' -207,0 ' and acknowledge the due execution of the
forgoing grassed swale maintenance requirements. Witness my hand and official seal,
K&k m .^', "�*
s
NOTARY
Z PUBLIC =
y*OVER 0,0J0
SEAL
My commission expires `7 I Zff Pq
Form SW401-Grassed Swale O&M-Rev.3 Page 2 of 2

DEMLR USE ONLY
Date Received Fee Paid Permit Number
STORMWATER PERMITTING FORM 7:
MINOR MODIFICATION
Standard Permitting Program — No Fee for Minor Modification
Express Permitting Program — See Express Fee Schedule
Only complete applications packages will be accepted and reviewed. This form and the required items (with
original signatures) must be sent to the appropriate DEMLR Regional Office, which can be determined by locating
the project on the interactive online map at. http://deg.nc.gov/contacUregional-offices.
This form is to only to be used by the current permittee to notify the Division of a minor
modification. Pursuant to Rule 15A NCAC 02H .1002. a minor modification is a change to the project that.
1) does not increase the net built -upon area; and/or
2) does not change the size or design of the SCM(s).
A. GENERAL INFORMATION
1. State Stormwater Permit Number: SW8 050547
2. Current Permit Holder's Company Name/Organization: New Hanover County Airport Authority
3. Signing Official's Name: Granseur Dick
4. Signing Official's Title: Facilities Director
5. Mailing Address: 1740 Airport Boulevard, Suite 12
City: Wilmington State: NC ZIP: 28405
6. Street Address (if different):
City: State: ZiP:
7. Phone: [phone] Email: gdick(aflyilm.com
8. Describe the minor modifications that you are requesting, including any revised BUA allocations (attach
additional pages or supporting tables similar to Section IV.10 of the original application, if needed):
The proposed project will be requesting an additional BUA reallocation of 117,649 sf of future allocation for
the Air Carrier Apron Expansion draining to EDDB #1 (under permit SW8-050547)
See additional pages.
B. SUBMITTAL REQUIREMENTS
Please mark "Y" to confirm the items are included with this form. Please mark `V if previously provided. if not
applicable or not available, please mark N/A.:
Y 1. Two hard copies (with original signatures) and one electronic copy of this completed form.
Y 2. Two hard copies and one electronic copy of the revised plan sheets (must be a revision of the
originally approved plan sheets).
X 3. If there is reallocation of lot BUA, a copy of the revised recorded deed restrictions and protective
revenants OR. the proposed recorded deed restrictions and protective covenants documenting
the changes and a signed agreement to provide the finai recorded document.
NA 4. If applicable, the appropriate Express review fee.
Stormwater Permit Form 7: Minor Modification Page 1 of 2 July 14, 2017

C. CONTACT INFORMATION
1. The Design Professional who is authorized to provide information on the Applicant's behalf:
Design Professional's Name: JD Lannou. PE
Consulting Firm: Talbert & Bright, Inc.
Mailing Address:4810 Shelley Drive
City:Wilmington State: NC Zip:28405
Phone: [phone] Fax: [phone]
Email::ilannou(a)-tlbiilfiserx; �i�;;1nn , c*M
2. [OPTIONAL] If you would like to designate another person to answer questions about the project:
Name & Title:
Organization:
Mailing Address:
City:_
Phone:
Email:
D. CERTIFICATION OF PERMITTEE
State: Zip:
ax: (
I, Granseur Dick , the current permittee, certify that I have authorized the minor modifications listed in
Section A and shown in the attached revised plan sheets. I further attest that this information is accurate and complete
to the best of my kUpwledge.
Signature:
/z/l1zozl
I, 9.0V M - a Notary Public for th State of 611, cc-q-, (i A" -
County of �f �� , do hereby certify that �GlhSf,L�r Dkc �
personally appeared before me this the S�- day of �Qr - yob e - , 20 a l , and
acknowledge the due execution of the forgoing instrument. Witness my hand and official seal,
�SSM
Seal) b��/cS�
Z NOTARY
a PUBLIC 2
Ne&ry Signature
�.� . "'� 0
"VE GGW l
My pires L
er 2021
Storri r:xtir Permit Form is ,.tinor k1odi'iication Papj • 2 of 2 C.;,L 15, 201

Table in Form SWU-101, Section IV. 10.
SW8 050547
Basin Information
Overall
Drainage Area
Phase I & If
Drainage Area
Pretreatment Swale #3 .
Drainage Area
Receiving Stream Name
Smith Cree
Smith Creek
Smith Creek
Stream Class
C, S
C, Sw
C, Sw
Stream Index Number
1 7 -63
18-74-63
18-74-63
Total Drainage Area (sf)
14 075
12,529,107
696,960
On -site Drainage Area (sf)
,041, 5
12,529,107
696,960
Off -site Drainage Area (sf)
0
0
0
Proposed Impervious Area (sf)
9,751,185
8,520,835
522,720
% Impervious Area (total)
69.4%
68.0%
75.0%
Impervious Surface Area
Overall %
Drainage Area 1 r
Phase l & II
Drainage Area,
Pretreatment Swale #3
Drainage Area
On -site Buildings/Lots (sf)
0
0
0
On -site Streets (sf)
1,994
1,994
1,994
On -site Parking (sf)
�89,9X
289,918
241,260
On -site Sidewalks (sf)
V0
0
Other on -site (sf)
A0
0
Future (sf)
,287, 5
2,057,505
180,879
Off -site (sf)
0
0
0
Existing BUA (sf)
6,171,418
6,171,418
98,587
Total (sf):
9,751,185
8,520,835
522,720
%0"",\\ 1 04""6 n
V%V UN a gall
cam'
IMP, eU� aM3
1c a�G 'C6►� ��

Permit Number:��
(to be provided by DWQ)
A "A O� m A. *I-
��F W pTF,QOG
9
MIEHR Ei
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
GRASSED SWALE SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part I//) must also be filled out, printed and submitted along with all of the required information.
Project name
CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
Contact name
RICK BAKER, PE
Phone number
919-8664939
Date
January 14,2021
Drainage area number
PHASE 3A
Site Characteristics
Drainage area
189,922.00 ftz
Impervious area
113,256.00 ftz
Percent impervious
59.6% %
Design rainfall depth
0.75 inch
Peak Flow Calculations
10-yrstorm runoff depth
10-yr storm intensity
Post -development 10-yr storm peak flow
Velocity
Maximum non -erosive velocity (peak 10-year storm)
Soil characteristics (enter "x" below)
Sand/silt (easily erodible)
Clay mix (erosion resistant)
Grass Type (enter 'Y' below)
Bermuda
Tall fescue
Bahiagrass
Kentucky bluegrass
Grass -legume mixture
Swale type: Fill out one of the options below:
Option 1: Curb Outlet Swale:
Maximum velocity
Side slopes
Swale length
Option 2: Swale Seeking Pollutant Credit ("For -Credit" Swale):
Maximum velocity for 10-yr storm
Side slopes
Swale length
NIA in
0.75 inlhr
2.50 ft3/sec
5.00 ft/sec
x
x
N
Y
0.61
6.00
1 r%n nn
Itillil
k CA
I -
f
(Y or N) 2
{{ "WinW
��11111 t 110N
(Y or N) 011140.1
ft/sec OK
:1 OK
ft OK
Form SW401-Grassed Swale-Rev.4 Parts I and II. Project Design Summary, Page 1 of 3

Permit Number:
(to be provided by DWQ)
Swale Characteristics
Swale Shape: Enter an'Y' in the appropriate cell below:
Trapezoidal
x
Parabolic
V-shaped
Width of the bottom of the swale
6.00 ft
Width of the top of the swale
18.00 ft
Additional information
Is the swale sized for all runoff from ultimate build -out?
Y (Y or N)
OK
Is the BMP located in a proposed drainage easement with a
recorded access easement to a public Right of Way (ROW)?
Y (Y or N)
OK
What is the distance from the bottom of the swale to the SHWf?
-4.65 ft
Insufficient distance to SHWT, unless conveyance swale only.
What is the ground level elevation?
21.67 fmsl
What is the elevation of the bottom of the swale?
16.35 fmsl
What is the SHWT elevation?
21.00 fmsl
What is the lonqitudinal slope of the swale?
0.10 %
OK
What is the depth of freeboard?
1.50 ft
OK
Form SW401-Grassed Swale-Rev.4 Parts I and II. Projeci Design Summary, Page 2 of 3

Permit No:
(to be assigned by DWQ)
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.
Initials Page/ Plan
Sheet No.
RB 1. Plans 0" = 50' or larger) of the entire site showing:
- Design at ultimate build -out,
- Off -site drainage (if applicable),
Delineated drainage basins (include Rational C coefficient per basin),
Swale dimensions (width, length, depth),
- Maintenance access,
- Proposed drainage easement and public right of way (ROW),
Grass species, and
Boundaries of drainage easement.
_RB 2. Plan details (V = 50' or larger) for the grassed swale showing:
- Swale dimensions (width, length, depth),
- Maintenance access,
- Proposed drainage easement and public right of way (ROM,
Design at ultimate build -out,
- Grass species,
- Off -site drainage (if applicable),and
- Boundaries of drainage easement.
_RB 3. Section view of the grassed swale (1" = 20' or larger) showing:
- Side slopes,
- Longitudinal slope,
- Freeboard
- Swale dimensions, and
- SHWT level(s)
_RB 4. Supporting calculations (including maximum velocity calculations for applicable storms)
_RB 5. A copy of the signed and notarized operation and maintenance (0&M) agreement.
6. A copy of the deed restrictions (if required).
SW401-Grassed Swale-Rev.3 Part III, Page 3 of 3

Permit Number: 5LA j OMS-
(to be provided by DWQ)
OF W ATF9
H=HR
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
401 CERTIFICATION APPLICATION FORM
GRASSED SWALE SUPPLEMENT
This form must be filled out, printed and submitted.
The Required Items Checklist (Part 111) must also be filled out, printed and submitted along with all of the required information.
Project name
CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NC.115
Contact name
RICK BAKER, PE
Phone number
919-866-4939
Date
January 14, 2021
Drainage area number
Phase 3B
Site Characteristics
Drainage area
680,076.00 ftz
Impervious area
367,596.00 ftz
Percent impervious
54.1 % %
Design rainfall depth
0.75 inch
Peak Flow Calculations
10-yr storm runoff depth
10-yr storm intensity
Post -development 10-yr storm peak flow
Velocity
Maximum non -erosive velocity (peak 10-year storm)
Soil characteristics (enter "x" below)
Sand/silt (easily erodible)
Clay mix (erosion resistant)
Grass Type (enter "x" below)
Bermuda -
Tall fescue
Bahiagrass
Kentucky bluegrass
Grass -legume mixture
Swale type: Fill out one of the options below:
Option 1: Curb Outlet Swale:
Maximum velocity
NIA
In
0.75
in/hr
8.80
ft3/sec
5.00 ftlsec
x
x
N (Y or N)
Side slopes :1
Swale length ft
Option 2: Swale Seekino Pollutant Credit ("For -Credit" Swale): Y (Y or N)
Maximum velocity for 10-yr storm 0.60 ft/sec OK
Side slopes 5.00 :1 OK
Swale length 150.00 ft OK
Form SW401-Grassed Swale-Rev.4 Parts I and 11. Project Design Summary, Page 1 of 3

Permit Number.
(to be provided by DWQ)
Swale Characteristics
Swale Shape: Enter an 'Y' in the appropriate cell below:
Trapezoidal
x
Parabolic
V-shaped
Width of the bottom of the swale
27.00 ft
Width of the top of the swale
34.50 ft
Additional Information
Is the Swale sized for all runoff from ultimate build -out?
Y (Y or N)
OK
Is the BMP located in a proposed drainage easement with a
recorded access easement to a public Right of Way (ROW)?
Y (Y or N)
OK
What is the distance from the bottom of the Swale to the SHWT?
-5.45 ft
Insufficient distance to SHWT, unless conveyance Swale only.
What is the ground level elevation?
20.67 fmsl
What is the elevation of the bottom of the Swale?
14.55 fmsl
What is the SHWT elevation?
20.00 fmsl
What is the longitudinal slope of the swale?
0.20 %
OK
What is the depth of freeboard?
0.25 ft
OK
Form SW401-Grassed Swale-Rev.4 Parts I and II. Project Design Summary, Page 2 of 3

Permit No:
(to be assigned by DWQ)
ID
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.
Initials Pagel Plan
Sheet No.
RB 1 Plans 0 = 50' or larger) of the entire site showing:
- Design at ultimate build -out,
- Off -site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
- Swale dimensions (width, length, depth),
- Maintenance access,
- Proposed drainage easement and public right of way (ROW),
Grass species, and
- Boundaries of drainage easement.
RB 2. Plan details (1" = 50' or larger) for the grassed swale showing:
Swale dimensions (width, length, depth),
Maintenance access,
Proposed drainage easement and public right of way (ROW),
Design at ultimate build -out,
Grass species,
Off -site drainage (if applicable),and
Boundaries of drainage easement.
_RB 3. Section view of the grassed swale (1" = 20' or larger) showing:
Side slopes,
- Longitudinal slope,
Freeboard
- Swale dimensions, and
- SHWT level(s)
_RB 4. Supporting calculations (including maximum velocity calculations for applicable storms)
_RB 5. A copy of the signed and notarized operation and maintenance (0&M) agreement.
_RB _ 6. A copy of the deed restrictions (if required).
SW401-Grassed Swale-Rev.3 Part lll, Page 3 of 3

11
Permit No. 5&J8 oaos"1
(to be provided by DWL)
OF WATT
OG
-AWA
STORMWATER MANAGEMENT PERMIT
APPLICATION FORM
WDENR
401 CERTIFICATION APPLICATION FORM
DRY EXTENDED DETENTION BASIN SUPPLEMENT
This form must be filled out,
printed and submitted.
The Required Items Checklist (Part I//) must be printed, filled out and submitted along with all the required information.
Project name
CIRCLE K - NTI AIRPORT BLVD WILMMTON - NC.115
Contact person
RICK BAKER, PE
Phone number
919-866-4939
Date
3/8/2021
Drainage area number
PHASE 3A
Site Characteristics
Drainage area
213,213.00
fe
Impervious area
116,598.00
ft�
% Impervious
0.55
Design rainfall depth
1.50
in
Peak Flow Calculations
1-yr, 24-hr rainfall depth
3.83
in
Rational C, pre -development
50.00
(unitless)
Rational C, post -development
76.00
(unitless)
Rainfall intensity: 1-yr, 24-hr storm
0.16
in/hr
eak
1.38
fe/sec
C'4•RO`/elr`�.
Post -development l-yr, 24hhrppea flow
1.34
ft/sec
•pO L'(H
Pre/Post 1-yr, 24-hr peak control
-0.04
fe/sec
Storage Volume: Non -SA Waters
SEAL r
Minimum required volume
14,416.00
fe
Provided volume
20,107.00
fe OK
Sediment storage volume provided
Storage Volume: SA Waters
5,691.00
ft3 OK
•�'' •G;N.:•,i�
y�. Q W. Bp
Iq1�/NN
1.5" runoff volume
ft3
D 3 `� 9f 2 /
Pre -development 1-yr, 24-hr runoff volume
ft,
Post -development 1-yr, 24-hr runoff volume
if
Minimum required volume
ft
Provided volume
ft3
Sediment storage volume provided
fe
Basin Design Parameters
Drawdown time
3.90
days
SHWT elevation
19.00
fmsl
Basin bottom elevation
14.50
fmsl
Storage elevation
17.70
fmsl
Basin side slopes
3.0
:1
Top elevation
2075
fmsl
Freeboard provided
1.50
It
Basin Bottom Dimensions
Basin length
220.00
It
Basin width
27.00
ft
Length to width ratio
8.00
:1
OK
Raise basin bottom, Must be at least 2-ft above SHWT
OK
OK
OK
OK
Form SW401-Dry Extended Detention Basin-Rev.3 Parts I. & II. Design Summary, Page 1 of 3

Additional Information
Total runoff volume captured by basin
Forebay provided
Is basin in a recorded drainage easement?
Does basin capture all runoff at ultimate build -out?
Is a sediment depth indicator included?
Does the basin include a drain?
12.55
ac-in
Forebay is required
N
(Y or N)
Y
(Y or N)
OK
Y
(Y or N)
OK
Y
(Y or N)
OK
Y
(Y or N)
OK
Permit
(to be provided by DWQ)
Form SW401-Dry Extended Detention Basin-Rev.3 Parts I. & II. Design Summary, Page 2 of 3

Permit
;4 94OLID RM C!*;"T
(to be provided by DWQ)
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.
Pagel Plan
Initials Sheet No.
_RB_ 1. Plans (1" - 50' or larger) of the entire site showing:
- Design at ultimate build -out,
- Off -site drainage (if applicable),
- Delineated drainage basins (include Rational C coefficient per basin),
- Basin dimensions,
- Pretreatment system,
- Maintenance access,
Proposed drainage easement and public right of way (ROW),
- Overflow device, and
- Boundaries of drainage easement.
_RB_ 2. Plan details (1" = 30' or larger) for the bioretention cell showing:
- Basin dimensions
Pretreatment system,
Maintenance access,
Outlet structure,
Overflow device,
Flow distribution detail for basin inflow, and
- Vegetation specifications.
3. Section view of the basin (1" 20' or larger) showing:
- Side slopes, 3:1 or lower,
- Pretreatment and treatment areas, and
- Inlet and outlet structures.
RB 6. A construction sequence that shows how the dry detention basin will be protected from sediment until the
entire drainage area is stabilized.
_RB 7. The supporting calculations.
_RB 8. A copy of the signed and notarized operation and maintenance (O&M) agreement.
_RB 9. A copy of the deed restrictions (if required).
_RB 10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
soil maps are not an acceptable source of soils information.
Form SW401-Dry Extended Detention Basin-Rev.3 Part III. Required Items Checklist, Page 3 of 3

Permit No. 5wf45 bS�Si-1�
(to be provided by DWQ)
of WA'r
RA STORMWATER MANAGEMENT PERMIT APPLICATION FORM
WDEI+lR 401 CERTIFICATION APPLICATION FORM c
DRY EXTENDED DETENTION E
This form must be filled out, printed and submitted.
The Required Items Checklist (Part //I) must be printed, filled out and submitted along with all the required information.
Project name
CIRCLE K - NTI AIRPORT BLVD WILMINGTON - NCA 15
Contact person
RICK BAKER, PE
Phone number
919-866-4939
Date
3/8/2021
Drainage area number
PHASE 3B
Site Characteristics
Drainage area
756,099.00
ftz
Impervious area
367,596.00
ft'
% Impervious
0.49
Design rainfall depth
1.50
in
Peak Flow Calculations
1-yr, 24-hr rainfall depth
3.83
in
Rational C, pre -development
50.00
(unitless)
Rational C, post -development
77.00
(unitless)
Rainfall intensity: 1-yr, 24-hr storm
0.16
inthr
Pre -development 1 yr, 24•hr pcak flow,
8.69
fOlsec
Post -development l-yr,24-hrpeak flow
1.37
ft3/sec
Pre/Post 1-yr, 24-hr peak control
-7.32
1'0/sec
ZN CAt�
Storage Volume: Non -SA Waters
-s�0¢0 60861 ski
Minimum required volume
46,037.00
ft3
� 9
Provided volume
61,848.00
fe OK
Sediment storage volume provided
15,811.00
ft' OK
�I
Storage Volume: SA Waters
1.5" runoff volume
ft3
Pre -development 1-yr. 24-hr runoff.volume
{
Post -development 1-yr, 24-hr runoff volume
fta
Minimum required volume
ft"
Provided volume
ft3
Sediment storage volume provided
ft3
Basin Design Parameters
Drawdown time
3.00
days
SHWT elevation
20.00
fmsl
Basin bottom elevation
13.25
fmsl
Storage elevation
16.50
fmsl
Basin side slopes
3.0
:1
Top elevation
20.00
fmsl
Freeboard provided
1.50
ft
Basin Bottom Dimensions
Basin length
700.00
ft
Basin width
51.00
ft
Length to width ratio
13.00
:1
a3/d 8/ -%
OK
Raise basin bottom, Must be at least 2-ft above SHWT
OK
OK
OK
OK
Form SW401-Dry Extended Detention Basin-Rev.3 Parts I. & II. Design Summary, Page 1 of 2

Permit No.
Additional Information
(to be provided by DWQ)
Total runoff volume captured by basin
44.83
ac-in
Forebay is required
Forebay provided
N
(Y or N)
Is basin in a recorded drainage easement?
Y
(Y or N)
OK
Does basin capture all runoff at ultimate build -out?
Y
(Y or N)
OK
Is a sediment depth indicator included?
Y
(Y or N)
OK
Does the basin include a drain?
Y
(Y or N)
OK
Form SW401-Dry Extended Detention Basin-Rev.3 Parts I. & II. Design Summary, Page 2 of 2

Permit
*, REQU'0*D ITEMFS CHECKLIST
(to be provided by DWQ)
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.
Pagel Plan
Initials Sheet No.
RB 1. Plans (1" - 50' or larger) of the entire site showing:
- Design at ultimate build -out,
- Off -site drainage (if applicable),
Delineated drainage basins (include Rational C coefficient per basin),
Basin dimensions,
- Pretreatment system,
Maintenance access,
Proposed drainage easement and public right of way (ROW),
Overflow device, and
Boundaries of drainage easement.
_RB_ _ 2. Plan details (1" = 30' or larger) for the bioretention cell showing:
- Basin dimensions
- Pretreatment system,
Maintenance access,
Outlet structure,
Overflow device,
Flow distribution detail for basin inflow, and
Vegetation specifications.
_rots_ 3. Section view of the basin 0" = 20' or larger) showing:
- Side slopes, 3:1 or lower,
- Pretreatment and treatment areas, and
- Inlet and outlet structures.
_RB 6. A construction sequence that shows how the dry detention basin will be protected from sediment until the
entire drainage area is stabilized.
_RB 7. The supporting calculations.
_RB 8. A copy of the signed and notarized operation and maintenance (O&M) agreement.
_RB 9. A copy of the deed restrictions (if required).
_RB 10. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County
soil maps are not an acceptable source of soils information.
Form SW401-Dry Extended Detention Basin-Rev.3 Part III. Required Items Checklist, Page 3 of 3