SW8980701_HISTORICAL FILE_19980915

STORMWATER DIVISION CODING SHEET
POST-CONSTRUCTION PERMITS
PERMIT NO. SW8 9 8 0-1 0 1
DOC TYPE ❑ CURRENT PERMIT
❑ APPROVED PLANS
HISTORICAL FILE
❑ COMPLIANCE EVALUATION INSPECTION
DOC DATE 1`1CAy 0CA15
YYYYMMDD

State of North Carolina
Department of Environment
and Natural Resources �!
Wilmington
Regional Office
James B. Hunt,Jr., Governor NCDENR
Wayne McDevitt, Secretary NORTH CAROLINA DEPARTMENT OF
Division of Water Quality ENVIRONMENT AND NATURAL RESOURCES
September 15, 1998
Mr. Tun Matt, President
Matt Holdings, LLC
1924 Lunar Lane
Wilmington, NC 28405
Subject: Permit No. SW8 980701
Triple T Parts and Equipment
High Density Commercial Stormwater Project
New Hanover County
Dear Mr. Matt:
The Wilmington Regional Office received the Stormwater Management Permit Application for Triple T Parts and
Equipment on July 1, 1998. Staff review of the plans and specifications has determined that the project, as proposed, will
comply with the Stormwater Regulations set forth in Title 15A NCAC 2H.1000. We are forwarding Permit No. SW8
980701 dated September 15, 1998, for the construction of Triple T Parts and Equipment.
This permit shall be effective from the date of issuance until September 15, 2008, and shall be subject to the conditions and
limitations as specified therein. Please pay special attention to the Operation and Maintenance requirements in this permit.
Failure to establish an adequate system for operation and maintenance of the stormwater management system will result
in future compliance problems.
If any parts, requirements, or limitations contained in this permit are unacceptable, you have the right to request an
adjudicatory hearing upon written request within thirty (30) days following receipt of this permit. This request must be
in the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the
Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-7447. Unless such demands are made this
permit shall be final and binding.
If you have any questions, or need additional information concerning this matter, please contact Linda Lewis, or me at
[phone].
Sincerely,
Rick Shiver
Water Quality Regional Supervisor
RSS/arl: S:\WQS\STORMWAT\PERMIT\980701.SEP__= - -_ -- _-
cc: Phil Tripp, P.E.
Tony Roberts, New Hanover County Inspections
Beth Easley, New Hanover County Engineering
Linda Lewis
Wilmington Regional Office
- - - -_ ---- --- -Central Files_.. - ` -
127 Cardinal Dr.Ext.,Wilmington,North Carolina 28405 Telephone [phone] FAX [phone]
--- - - An,Equal Opportunity Affirmative Action Employer .. —:�-__: -- 50%.recycled/10%:post-consumer paper

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State Stormwater Management Systems
Permit No SW8 980701
STATE OF NORTH CAROLINA
DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES
DIVISION OF WATER QUALITY
STATE STORMWATER MANAGEMENT PERMIT
HIGH DENSITY DEVELOPMENT
In accordance with the provisions of Article 21 of Chapter 143, General Statutes of North Carolina as amended, and other
applicable Laws, Rules, and Regulations
PERMISSION IS HEREBY GRANTED TO
Matt Holdings, LLC
Triple T Parts and Equipment
New Hanover County
FOR THE
construction, operation and maintenance of a detention pond 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.
This permit shall be effective from the date of issuance until September 15, 2008 and shall be subject to the following
specified conditions and limitations:
I. DESIGN STANDARDS
1. This permit is effective only with respect to the nature and volume of stormwater described in the application and
other supporting data.
2. This stormwater system has been approved for the management of stormwater runoff as described on page 3 of this
permit, the Project Data Sheet. The stormwater control has been designed to handle the runoff from 253,494 square
feet of impervious area. This pond is designed to be operated with a vegetated filter.
3., - Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the
permit.
4. The tract will be limited to the amount of built-upon area indicated on page 3 of this permit, and per approved
plans.
2

State StOrmwater Management Systems
Permit No. SW8 980701
DIVISION OF WATER QUALITY
PROJECT DATA SHEET
Project Name: Triple T Parts and Equipment '
Permit Number: 980701
Location: New Hanover County
Applicant: Mr. Tim Matt, President
Mailing Address: Matt Holdings, LLC
1924 Lunar Lane
Wilmington, NC 28405
Application Date: July 1, 1998
Water Body Receiving Stormwater Runoff: NE Cape Fear River
Classification of Water Body: "C"
If Class SA, chloride sampling results: n/a
Pond Depth, feet: 7
Permanent Pool Elevation, FMSL: 10
Total Impervious Surfaces, ft2: 253,494
Outparcels, ft2-_ n/a
Future, ft2 n/a
Offsite Area entering Pond, ftz: None, per Engineer
Required Surface Area, ft2: 10,735
Provided Surface Area, ft2: 10,962
Required Storage Volume, ft3: 20,359
Provided Storage Volume, ft3: 25,792
Temporary Storage Elevation, FMSL: 12
-.. .: Controlling Orifice:. : ::, `__-=2.25"�.ptpe _.
3 -

' v
State Stormwater Management Systems
Permit No SW8 980701
5. All runoff from the built-upon area on the project must be directed into the permitted stormwater control system.
6. The permittee is responsible for verifying that the proposed built-upon area does not exceed the allowable built-
upon area.
7. The following items will require a modification to the permit:
a. Any revision to the approved plans, regardless of size.
b. Project name change.
C. Transfer of ownership.
d. Redesign or addition to the approved amount of built-upon area.
e. Further subdivision of the project area.
f. Filling in, altering, or piping of any vegetative conveyance shown on the approved plan.
In addition, the Director may determine that other revisions to the project should require a modification to the
permit.
8. 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.
II. SCHEDULE OF COMPLIANCE
1. The stormwater management system shall be constructed in it's entirety, vegetated and operational for its intended
use prior to the construction of any built-upon surface except roads.
2. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired
immediately_
3. The permittee shall at all times provide the operation and maintenance necessary to assure the permitted stormwater
system functions at optimum efficiency. The approved Operation and Maintenance Plan must be followed in its
entirety and maintenance must occur at the scheduled intervals including, but not limited to:
a. Semiannual scheduled inspections (every 6 months).
b. Sediment removal.
C. Mowing and 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.
4. Records of maintenance activities must be kept and made available upon request to authorized personnel of DWQ.
=The records will indicate the dafe activity, name of-person-performing the work and what actions were taken.
5. Decorative spray fountains will not be allowed in the ponds.
6. This permit shall become voidable unless the facilities are constructed in accordance with the conditions of this
permit, the approved plans and_specifcations, and other_supporting-data.__
- -
- - - — - 4

P "
State Stormwater Management Systems
Permit No SW8 980701
7. Upon completion of construction, prior to issuance of a Certificate of Occupancy, and prior to operation of this
permitted facility, a certification must be received from an appropriate designer for the system installed certifying
that the permitted facility has been installed in accordance with this permit, the approved plans and specifications,
and other supporting documentation. Any deviations from the approved plans and specifications must be noted on
the Certification.
8. A copy of the approved plans and specifications shall be maintained on file by the Permittee for a minimum of ten
years from the date of the completion of construction.
9. Prior to the sale of any portion of the property, an access/maintenance easement to the stormwater facilities shall
be granted in favor of the perminee if access to the stormwater facilities will be restricted by the sale of any portion
of the property.
III. GENERAL CONDITIONS
1. This permit is not transferable. In the event there is a desire for the facilities to change ownership, or there 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.
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 facilities fail to perform satisfactorily, including the creation of nuisance conditions, the
Permittee shall take immediate corrective action, including those as may be required by this Division, such as the
construction of additional or replacement stormwater management systems.
5. The permittee grants DENR Staff permission to enter the property for the purpose of inspecting all 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.
Permit issued this the 15th day of September, 1998.
NORTH CAROLINA ENVIRONMENTAL_MANAGEMENT_COMMISSION -_:: --
A. Preston Howard, Jr., P.E., Director
Division of Water Quality
A- -By-Authority--of the-Environmental.Mina ementCommission^
umb
er SW8-980701
5

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State Stormwater Management Systems
Permit No SW8 980701
Triple T Parts and Equipment
Stormwater Permit No. SW8 980701
New Hanover County
Engineer's Certification
I, as a duly registered Professional Engineer 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.
Noted deviations from approved plans and specification:
SEAL
Signature - — -
Registration Number
Date

a ., L}FFICE•USE:.C3N1 Y ..::. E�51P{..Cc)'.S e.. 31 b...A �...e
Date Received Fee Paid Permit Number
o �9 70
State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
This form may be photocopied for use as an original
I. GENERAL INFORMATION
1. Applicants name(specify the name of the corporation, individual, etc. who owns the project):
Matt Holdings, LLC
2. Print Owner/Signing Official's name and title (the person who is legally responsible for the facility and
its compliance):
Tim MgJ President & Owner
3. Mailing Address for person listed in item 2 above:
1924 Lunar Lane
City: Wilmington State: NC Zip: 28405
Telephone Number: [phone]
4. Project Name(subdivision, facility, or establishment name—should be consistent with project name on
plans, specifications, letters, operation and maintenance agreements, etc.):
Triple T Parts and FAuipment
5. Location of Facility(street address):
2715 U S Hwy 421 North
City: Wilmington County: New Hanover
6. Directions to facility(from nearest major intersection):
Approx. 1000 If North from the intersection of U S Hwy 421 and SR 1347
7. Latitude : N34016'30" Longitude: W77°57'30" of facility
8. Contact person who can answer questions about the facility:
Name: Phillip G. Tripp Telephone Number: [phone]
II. PERMIT INFORMATION:
1. Specify whether project is (check one): X New Renewal Modification
2. If this application is being submitted as the result of a renewal or modification to an existing permit, list
The existing permit number and its issue date(if known)
Form SWU-101 January 1998 Page 1 of 4

3. Specify the type of project(check one):
Low Density __2L High Density Redevelop General Permit Other
4. Additional Project Requirements (check applicable blanks):
CAMA Major X Sedimentation/Erosion Control 404 Permit
III. PROJECT INFORMATION
1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed
narrative(one to two pages)describing stormwater management for the project.
Stormwater detention pond
2. Stormwater runoff from this project drains to the Cape Fear River basin.
3. Total Project Area: 7.42 _acres 4. Project Built Upon Area: 78.4 %.
5. How many drainage basins does the project have? 1
6. Complete the following information for each drainage basin. If there are more than two drainage basins
in the project, attach an additional sheet with the information for each basin provided in the same format
as below.
e-Brim. D e 2
»,�.� ... a .»� . .
a< in,IrrPormaton �.�
Receiving Stream Name N.E. Cape Fear
Receiving Stream Class C SW
Drainage Basin Area 7.42 acres
Existing Impervious * Area 2.85 acres
Proposed Impervious * Area 2.96 acres
%Impervious* Area(total) 78.4%
MR 1 o s ,"tuface_ ea e>tasin
On-site Buildings 41,046 sf
On-site Streets N/A
On-site Sidewalks 6,696 sf
On-site Parking 205,752 sf
Other on-site N/A
Off-site N/A
Total: E=253,494 sf E=
*Impervious area is defined as the built upon area including, but not limited to, buildings, roads,parking
areas sidewalks, gravel areas, etc.
7. How was the off-site impervious area listed above derived? N/A
IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS
Deed restrictions and protective covenants are required to be recorded for all low density projects and all
subdivisions prior to the sale of any lot. Please see Attachment A for the specific items that must be recorded.
Form SWU-101 January 1998 Page 2 of 4

By your signature below, you certify that the recorded deed restrictions and protective covenants for this project
shall include all the items required by the permit,that the covenants will be binding on all patties and persons
claiming under them,that they will run with the land,that the required covenants cannot be changed or deleted
without concurrence from the State, and that they will be recorded prior to the sale of any lot.
V. AGENT AUTHORIZATION
If you wish to designate submittal authority to another individual or firm so that they may provide information
on your behalf,please complete this section:
Designated agent(individual or firm): Tripp Engineering, P.C.
Mailing Address: 507 Chestnut Street
City: Wilmington State: NC Zip: 28401
Phone: [phone] Fax: [phone]
VII. SUBMITTAL REQUIREMENTS
This application package will not be accepted by the Division of Water Quality unless all of the applicable
items are included with the submittal.
1. Please indicate that you have provided the following required information by signing your initials in the
space provided next to each item.
Ap 'cant's Initials
• Original and one copy of the Stormwater Management Permit Application Form
• One copy of the applicable Supplement Form(s) for each BMP (see Attachment A)
• Permit application processing fee(see Attachment A)
• Detailed narrative description of stormwater treatment/management
• Two copies of plans and specifications, including:
- Development/Project name
- Engineer and firm
- Legend
- North arrow
- Scale
- Revision number and date
- Mean high water line
- Dimensioned property/project boundary
- Location map with named streets or NCSR numbers
- Original contours,proposed contours,spot elevations
- Details of roads,parking, cul-de-sacs, sidewalks,and curb and gutter
- Wetlands delineated, or a note on plans that none exist
- Existing drainage(including off-site), drainage easements,pipe sizes, runoff calculations
- Drainage basins delineated
- Vegetated buffers(where required)
VI. APPLICANT'S CERTIFICATION
I, (print or type name of person listed in General Information, item 2) Tim Matt certify
that the information included on this permit application form is correct,that the project will be constructed in
conformance with the approved plans, that the deed restrictions in accordance with Attachment A of this form
will be recorded with all required permit conditions, and that to the best of my knowledge,the proposed project
complies with the requiem nts o SA r AC 21-1 .1000.
Signature: �(j Date: 0(0�'�
Title: President er
Form SWU-101 January 1998 Page 3 of 4

ATTACHMENT A IP
1. Deed Restriction Language
The following statement must be recorded for all low density projects and for all projects that involve the
subdivision and selling of lots or outparcels:
1. No more than square feet of any lot, including that portion of the right-of-way between the
edge of pavement and the front lot line, shall be covered by impervious structures including asphalt,
gravel, concrete, brick, stone, slate or similar material but not including wood decking or the
surface ofswimming pools. This covenant is intended to insure continued compliance with the
stormwater permit issued by the State of North Carolina. The covenant may not be changed or
deleted without the consent of the State.
2. No one may fill in,pipe, or alter any roadside Swale except as necessary to provide a minimum
driveway crossing.
NOTE: If lot sizes vary significantly,the owner/developer must provide an attachment listing each lot
number, size and the allowable built upon area for each lot.
For commercial projects that have outparcels or future development, the following statements must also be
recorded:
3. The connection from the outparcel or future area into the stormwater system must be made into the
forebay such that short-circuiting of the system does not occur.
4. All built-upon area from the outparcel or future development must be directed into the permitted
stormwater control system.
5. Built-upon area in excess of the permitted amount will require a permit modification prior to
construction.
For curb outlet systems,the following statement in addition to items I and 2 above must berecorded:
6. No one may pipe,fill in or alter any designated 100 foot long grassed swale used to meet the
requirements ofNCAC 2H.1008(g).
2. Supplement Forms
The applicable supplement form(s) listed below must be submitted for each BMP specified for this project:
Form SWU-102 Wet Detention Basin Supplement
Form SWU-103 Infiltration Basin Supplement
Form SWU-104 Low Density Supplement
Form SWU-105 Curb Outlet System Supplement
Form SWU-106 Off-Site System Supplement
Form SWU-107 Underground Infiltration Trench Supplement
Form SWU-108 Neuse River Basin Nutrient Management Strategy Supplement
3. Permit Application Fees (check made payable to NCDENR and submitted to the appropriate
Regional Office)
Type of Permit -New, Modification, or Timely Renewal Without
Late Renewal Modification
Low Density $225 n/a
High Density $385 $225
Other $225 n/a
Director's Certification $350 n/a
General Permit $ 50 n/a
Form SWU-101 January 1998 Page 4 of 4

POND MAINTENANCE REQUIREMENTS
PAGE 2
---------------------------------------------------------
IV. Annually (Once a year)
A. The pond depth will be checked at various points. Sediment removal is required when the
depth is reduced to 75% of the original design depth or 3', whichever is greater. Design
depth is �� , measured vertically from the orifice down to the pond's bottom.
Sediment must be removed to at least the original design depth.
V. General:
A. Mowing of the side slopes will be accomplished according to the season. Maximum grass
height will be 6".
B. Cattails are encouraged along the pond perimeter, however they will be removed when
they cover more than '/2 the surface area of the pond.
C. The orifice/pump is designed to draw down the pond in 2-5 days. If drawdown is not
accomplished in that time, the system will be checked for clogging. The source of the
clogging will be found and eliminated.
D. All components of the detention pond system will be kept in good working order. Repair
or replacement components will meet the original design specifications as per the approved
stormwater plan.
VI. Special Requirements:
I, Tim Matt hereby acknowledge that I am the financially
responsible party for maintenance of this detention pond. I will perform the maintenance as outlined
above, as part of the Certificatio Co iance with Stormwater Regulations received for this project.
Signature: Date: 0(01111%
DA/arl: S:\WQS\STORMWAT\FORMS\O&M-POND.FOR

TE 98051
Permit No. gy07D 1
(to be provided by DWQ)
State of North Carolina
Department of Environment and Natural Resources
Division of Water Quality
STORMWATER MANAGEMENT PERMIT APPLICATION FORM
WET DETENTION BASIN SUPPLEMENT
This form may be photocopied for use as an original
DWO Stormwater Management Plan Review:
A complete stormwater management plan submittal includes a wet detention basin supplement for each basin,
design calculations, plans and specifications showing all basin and outlet structure details, and a fully executed
operation and maintenance agreement.
I. PROJECT INFORMATION (please complete the following information):
Project Name : Triple T Parts & Equipment
Contact Person: Phillip G. Tripp, P.E. Phone Number: ( 910 ) 763-5100
For projects with multiple basins, specify which basin this worksheet applies to:
Basin Bottom Elevation 3.0 ft. (average elevation of the floor of the basin)
Permanent Pool Elevation 10.0 ft. (elevation of the orifice)
Temporary Pool Elevation 12.0 ft. (elevation of the discharge structure overflow)
Permanent Pool Surface Area 10,962 sq. ft. (water surface area at the orifice t elevation)
Drainaee Area 7.42 ac. (on-site and off-site drainage to the basin)
Impervious Area 5.82 ac. (on-site and off-site drainage to the basin)
Permanent Pool Volume 44,492 cu. ft. (combined volume of main basin and forebay)
Temporary Pool Volume 25,792 cu. ft. (volume detained above the permanent pool)
Forebay Volume 4,877 cu. ft.
SA/DAt used .0335 (surface area to drainage area ratio)
Diameter of Orifice 2.25 in.
Design TSS Removal 90 % (85% TSS removal required, see item k below)
II. REQliIRED ITEMS CHECKLIST
The following checklist outlines design requirements per the Stormwater Best Management Practices manual
(N.C. Department of Environment, Health and Natural Resources, November 1995) and Administrative Code
Section: 15 A NCAC 2H .1008.
Initial in the space provided to indicate the following design requirements have been met and supporting
documentation is attached. If the applicant has designated an agent in the Stormwater Management Permit
Application Form, the agent may initial below. If a requirement has not been met, attach justification.
Form SWU-102 January 1998 Page I of 2

Applicants Initials
a. The temporary pool controls runoff from the 1 inch storm event.
b. The basin length to width ratio is greater than 3:1.
c. The basin side slopes above the permanent pool are no steeper than 3:1.
d. A submerged and vegetated perimeter shelf at less than 6:1 is provided (show detail).
e. Vegetation above the permanent pool elevation is specified.
f. An emergency drain is provided to empty the basin.
g. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet).
It. The temporary pool draws down in 2 to 5 days.
i. A trash rack is provided for both the overflow and orifice.
j. The forebay volume is approximately equal to 20% of the total basin volume.
k. Sediment storage is provided in the permanent pool.
1. A 30-foot vegetative filter is provided at the outletz (include erosive flow calculations)
m. Recorded drainage easement for each basin including access to nearest right-of-way.
n. A site specific operation and maintenance (0&.'vf) plan is provided.
o. A veeetation management/mowing schedule is provided in the 0&_M plan.
p. Semi-annual inspections are specified in the 0&M plan.
q. A debris check to be performed after every storm event is specified in the 0&."vI plan.
r. Specific clean-out benchmarks are specified in the 0&-1 plan (elevation or depth).
s. A legally responsible party is designated in the 0&.Ivf plan3 (include name and title).
t. If the basin is used for sediment and erosion control durine construction. clean out of the
basin is specified to be performed prior to use as a wet detention basin.
Foomoies:
1 When using the Division SA/DA tables. the correct SA/DA ratio for permanent pool sizing should be computed based upon the
actual impervious% and permanent pool depth. Linear interpolation should be employed to determine the correct value for non-
standard table entries.
Z The requirement for a vegetative filter may be waived if the wet detention basin is designed to meet 90% TSS removal.
3 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.
�(51(aN�J7 -ro 7' A5 ?EK tkDeNr rABL-eS .
Form SWli-102 lanuary 1998 Paee 2 of 2

TE 98o51
POND MAINTENANCE REQUIREMENTS Project Name: _Triple T Parts and Equipment Project No. _' ' 'lS��y
go w3wj-
Responsible Party: _Matt Holdings, L.L.C. Phone No. [phone]
Address: 1924 Lunar Lane, Wilmington, NC 28405
I. Monthly, or after every runoff producing rainfall event, whichever comes first:
A. Inspect trash rack; remove accumulated debris, repair/replace if it is not functioning.
B. Inspect and clear the orifice of any obstructions. If a pump is used as the drawdown
mechanism, pimp operation will be checked. A log of test runs of the pump will be kept
on site and made available to DEM personnel upon request.
C. Inspect the pond side slopes and grassed inlet swales; remove trash, and repair eroded
areas before the next rainfall event.
D. If the pond is operated with a vegetated filter, the filter will be checked for sediment
accumulation, trash accumulation, erosion and proper operation of the flow spreader
mechanism. Repairs/cleaning will be done as necessary.
II. Quarterly:
A. Inspect the collection system (i.e. catch basins, piping, grassed swales) for proper
functioning. Accumulated trash will be cleared from basin grates, basin bottoms, and
piping will be checked for obstructions and cleared as required.
B. Pond inlet pipes will be checked for undercutting, riprap or other energy dissipation
structures will be replaced, and broken pipes will be repaired.
III. Semi-annually:
A. Accumulated sediment from the bottom of the outlet structure will be removed.
B. The pond depth will be checked at various points. Sediment removal is required when the
depth is reduced to 75% of original forebay design of _6'
C. Grassed swales, including the vegetated filter if applicable, will be reseeded twice a year as
necessary. STOR ,WATER
E C E I V E
JUL 011998 D
D E M
PROJ #------
�

TRIPP ENGINEERING, P.C.
D l 507 Chestnut Street
I } Wilmington, North Carolina 28401
3� Phone: [phone] Fax: [phone]
q ?D 70 Z RECEIVED
June 30, 1998 JUL 01 1998
NCDENR BY:
Division of Environmental Management
Water Quality Section
127 Cardinal Drive
Wilmington, NC 28405-3845
Attn: Ms. Linda Lewis
Re: Triple T Parts & Equipment
New Hanover County, NC
TE No. 98051
Dear Linda:
Enclosed please find two(2) sets of plans, one(1) signed original and one (1)
copy of the application form including narrative, one (1)O& M, one (1)wet detention
supplement, two (2) sets of sealed calculations and one (1) check to cover the application
fee.
Please review for approval and contact us with any questions or comments. Thank
you.
Sincerely,
Tripp Engineering, P.C.
Phillip G. Tripp
PGT:jss
Enc.

i�• 'r . fd:1 '. r 7
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J ' .r77':'f .,

June 30, 1998
Re: Triple"T'Parts and Equipment
2715 US Hwy 421 North
New Hanover County,NC
TE 98051
Stormwater Narative
The Triple"T"Parts and Equipment 7.42 acre site is to be cleared and graded for the addition of a
22,360 sf building. Also included is an addition of 106,682 sf of gravel drive and parking.
Runoff from this site is routed to a proposed detention pond designed for the existing and
proposed area on this lot. The pond will capture and treat the first inch of runoff from all areas. We
anticipate no entry of off-site runoff from evaluation of existing on and off-site contours.

6/26/98 TRIPLE T 98051
CDC Stormwater Calculations
Total Drainage Area
ft. I acres
323,215 7.42
Impervious Area
Land Use sq.R. acres %impervious- 0.784
EXISTING BUILDING 18,686 0.43 = 78 4%
EXISTING CONCRETE 6,696 0.15
EXISTING GRAVEL 65,442 1.50
EXISTING ASPHALT 33,628 0.77
PROPOSED BUILDING 22,360 0.51
PROPOSEDGRAVEL 106.682 2.45
Total 253,494 5.82
Stormwater Calculations:
Time of Concentration:
Hydraulic Length(L)= 450 R. CPRe= 0.25
change in Height(H)= 15 ft. C�_ (%imp.)(.95)+(1-%imp.)(.25)
Tc = (L'/H)'�/128 = 0.80
3.19 min. 11a= ;7.23 in/hr
Iw= 8.87 in/hr
Flow for 10 year,6 hour Storm(O.a):
QPRE- (CPRR)x(110)x(Area) Flow for 50 year,6 hour Storm(0,,a):
13.41 cis OPRE= (CPRE)x(lam x(Area)
OPosr= (CP ar)x(110)x(Area) = 16.45 cis
= 42.86 cfs 0�_ (C�)x(I5,)x(Area)
52.59 cis
Sail Storage Capacity for 10 year Storm:
CN= (98)(%imp.)+(60)(1-%imp.) Soil Storage Capacity for 50 year Storm:
90 CN= (98)(%imp.)+(60)(1-%imp.)
P= 4.80 in. for 10 yr,6 hr stone = 90
S= 1000/CN-10 P= 6.42 in. for 50 yr,6 hr storm
1.11 S= 1000/CN-10
Depth(D)= [P-(0.2)(S)12/[P+(0.8)(S)I = 1.11
3.68 in. Depth(D)= [P{0.2)(S)]'/[P+(0.8)(S)]
5.26 in.
Time to Peak Flow:
TP= [(43.5)(D)(Area)]/O1o.Posr Time to Peak Flow:
= 27.74 min. TP= [(43.5)(D)(Area)I/OSOPosr
32.26 min.
Detention Pond Design,
Pond Size:
Elevation Surface Area State Surface Area Requirement at normalpool:
ft. s .ft. Pond side slopes= 3 :1
Normal Pool 10.00 10,962 Depth below N.P.= 7 ft.
Flood Pool 12.00 14,830 SA/DA= 0.0335
Top of Bank 14.M 18,933 (Chart for 90%TSS Removal for Wet Detention
Bottom of Pool 3.00 1,750 Pond without Vegetative Fitter
Required SA= (SA/DA)x(Total Drainage Area)
10.828 sq.ft.
Total Provided Storage Volume: State Volume Requirement for first 1'of runoff:
Vol._ [(Normal pool SA+Flood Pool SA)!2] Vol._ [(1/12)x(DA)x(%imp.)1+
x(Flood Pool elev.-N.P.elev.) [(1/12)x PA)x(1-%imp.)x CI
25,792 cu.ft. C= 0.2
22,287 cu.ft.
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6/26/98 TRIPLE T 98051
CDC Stormvwter Calculations
For_ ebaw
Required Volume Provided Volume
Vol.= 20%of state storage volume fft
= 1,844 sq.R.
4,457 cu.ft. = 3.033 .ft.
_ [(N.P.SA+F.P.SA)!21 x(F.P.at.-N.P.el.)
4,877 cu.ft.
= 3ft.
Outlet Structure Design:
Flow for 2-day dmwdown: Flow for Sda drewdown:
for 1st 1'of stormwater, for 1st 1'of stonnwaler,
Q= Provided Vol.1172,800 sec.(2days) Q= Provided Vol.1432.000 sec.(5-days)
0.149 cfs — 0.060 cfs
Required Area of Pipe for 2-day drawdown: R uired Area of Pipe for 5-day drawdown:
A= Q/[Cdx SQRT(2xgxh)] A= Q/[Cdx SQRT(2xgxh)]
Cd= 0.6 Cd= 0.6
g= 32.2 R./s' g= 32.2 ft./s'
h= (F.P..elev.-N.P.elev.)/2 h= (F.P.elev.-N.P.elev.)/2
A= 0.0310 sq.ft. A= 0.0124 sq.ft.
Diameter of Pipe for 2-day drawdown: Diameter of Pipe for 5-day drawdown:
Ea
SQRT[(A x 4)/pi] DIA.= SQRT[(A x 4)!pi]
0.1987 ft. = 0.1256 ft.
2.38 in. — 1.51 in.
USE:2.25 in ORIFICE
Outlet Structure Check:
Using a W x 6 Basin,
Perimeter 12= 16 ft.
Q= CIA
C= (%imp.)(.95)+(1-%imp.)(.25)
0.80
1= 7.23 in+for a 10 yr.Storm
A= 7.42 Acres
42.86 cfs
Q= CwxLx Hls
H= [Q/(CwxL)]'
Cw= 3
0.93 ft.
Peak elevation= flood pool elevation+H
12.93 ft.
98051POND.xIs 2 of