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HomeMy WebLinkAboutSW8991003_CURRENT PERMIT_20041230STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. DOC TYPECURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE- WYYMMDD �OF WATFRQ Michael F. Easley, Governor p G William G. Ross, Jr., Secretary r North Carolina Department of Environment and Natural Resources 4 'c Alan W. Klimek, P.E. Director Division of Water Quality December 30, 2004 Jon W. Rosborough, Airport Director Wilmington International Airport 1740 Airport Boulevard Wilmington, NC 28405 Subject: Stormwater Permit No. SW8 991003 Modification Wilmington International Airport T-Hanger Project - Phase III High Density Project New Hanover County Dear Mr. Rosborough: The Wilmington Regional Office received a complete Stormwater Management Permit Application for Wilmington International Airport T-Hanger Project - Phase III on December 30, 2004. 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 991003.Modification dated December 30, 2004, for the construction of the subject project. This permit shall be effective from the date of issuance until December 30, 2014, 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 Rhonda Hall, or me at (910) 395-3900. Sincerely, / ! - Rick Shiver Regional Supervisor Surface Water Protection Section RSSlrbh: S:IWQSISTORMWATIPERMIT1991003 Mod_dec.04 cc: Phillip Norris, P.E., Norris, Kuske & Tunstall Consulting Engineers, Inc. New Hanover County Building Inspections City of Wilmington Stormwater Services Beth E. Wetherill, New Hanover County Engineering Rhonda Hall rUVilmingtori Regional Office Central Files North Carolina Division of Water Quality 127 Cardinal Drive Extension Phone (910) 395-3900 Customer Servicel-877-623-6748 Wilmington Regional Office Mminglon, NC 28405-3845 FAX (919) 733.2496 Internet: h2o.enr,state.nous one NorthCarolina An Equal OpportunAylAffirmat'ive Action Employer — 50% Recycled110% Post Consumer Paper XMlP 1111 State Stormwater Management Systems Permit No. SW8 991003 Modification 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 Jon W. Rosborough, Wilmington International Airport Wilmington International Airport T-Hanger Project - Phase Ill New Hanover County FOR THE construction, operation and maintenance of a dry detention basin 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 Deember 30, 2014, and shall be subject to the following specified conditions and limitations; I. DESIGN STANDARDS 1. This permit is effective only with respect to the nature and volume of stormwater described in the application and other supporting data. 2. This stormwater system has been approved for the management of stormwater runoff as described in Section 1.6 on page 3 of this permit. The stormwater control has been designed to handle the runoff from 88,840 square feet of impervious area. This basin must be operated with a vegetated filter. 3. The tract will be limited to the amount of built -upon area indicated on page 3 of this permit, and per approved plans. 4. All stormwater collection and treatment systems must be located in either dedicated common areas or recorded easements. The final plats for the project will be recorded showing all such required easements, in accordance with the approved plans. 5. The runoff from all built -upon area within the permitted drainage area of this project must be directed into the permitted stormwater control system. Page 2 of 7 State Stormwater Management Systems Permit No. SW8 991003 Modification Co The following design criteria have been provided in the dry detention basin and must be maintained at design condition: a. Drainage Area, acres: 4.29 Onsite, ft2: 186,853 Offsite, ft2: None b. Total Impervious Surfaces, ft2: 88,840 C. Bottom Elevation, FMSL: 18.5 d. Permitted Surface Area, ft2: 3,138 e Storage Elevation, FMSL: 20.0 f. Required Storage Volume, ft3: 9,037 g. Permitted Storage Volume, ft3: 9,183 h. Controlling Orifice: 1 "0 pipe i. Additional BMP: Grassed Swale j. Receiving Stream/River Basin: Smith Creek/Cape Fear k. Stream Index Number: 18-74-63 I. Classification of Water Body: "CISw" II. SCHEDULE OF COMPLIANCE 1. The stormwater management system shall be constructed in its entirety, vegetated and operational for its intended use prior to the construction of any built -upon surface. 2. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately. 3. The permittee shall at all 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 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. 4. Records of maintenance activities must be kept and made available upon request to authorized personnel of DWQ. The records will indicate the date, activity, name of person performing the work and what actions were taken. Page 3 of 7 State Stormwater Management Systems Permit No. SW8 991003 Modification 5. The facilities shall be constructed as shown on the approved plans. This permit shall become voidable unless the facilities are constructed in accordance with the conditions of this permit, the approved plans and specifications, and other supporting data. 6. Upon completion of construction, prior to issuance of a Certificate of Occupancy, and prior to operation of this permitted facility, a certification must be received from an appropriate designer for the system installed certifying that the permitted facility has been installed in accordance with this permit, the approved plans and specifications, and other supporting documentation. Any deviations from the approved plans and specifications must be noted on the Certification. A modification may be required for those deviations. 7. 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. 8. Access to the stormwater facilities shall be maintained via appropriate easements at all times. 9. The permittee shall submit to the Director and shall have received approval for revised plans, specifications, and calculations prior to construction, for any modification to the approved plans, including, but not limited to, those listed below: a. Any revision to any item shown on the approved plans, including the stormwater management measures, built -upon area, details, etc. b. Project name change. C. Transfer of ownership. d. Redesign or addition to the approved amount of built -upon area or to the drainage area. e. Further subdivision, acquisition, lease or sale of all or part of the project area. The project area is defined as all property owned by the permittee, for which Sedimentation and Erosion Control Plan approval or a CAMA Major permit was sought. f. Filling in, altering, or piping of any vegetative conveyance shown on the approved plan. 10. The permittee shall submit final site layout and grading plans for any permitted future areas shown on the approved plans, prior to construction. 11. 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. 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. III. GENERAL CONDITIONS This permit is not transferable except after notice to and approval by the Director. In the event of a change of ownership, or a name change, the permittee must submit a formal permit transfer request to the Division of Water Quality, accompanied by a completed name/ownership change form, 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 Page 4 of 7 State Stormwater Management Systems L"I Permit No. SW8 991003 Modification be approved. The permittee is responsible for compliance with all permit conditions until such time as the Division approves the transfer request. 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) having 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 during normal business hours 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. 7. Unless specified elsewhere, permanent seeding requirements for the stormwater control must follow the guidelines established in the North Carolina Erosion and Sediment Control Planning -and Design Manual. 8. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. 9. The permittee shall notify the Division any name, ownership or mailing address changes within 30 days. Permit issued this the 301" day of December, 2004. NORT�I CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION Ahai'i W. Klimek, P.E., Director Division of Water Quality By Authority of the Environmental Management Commission Page 5 of 7 State Stormwater Management Systems Permit No. SW8 991003 Modification Wilmington International Airport T-Hanger Project, Phase Ill Stormwater Permit No. SW8 991003 Modification New Hanover County Designer's Certification I, , as a duly registered in the State of North Carolina, having been authorized to observe (periodically/ weekly/ full time) the construction of the project, (Project) for (Project Owner) hereby state that, to the best of my abilities, due care and diligence was used in the observation of the project construction such that theconstruction 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. F Noted deviations from approved plans and specification: Signature Registration Number Date SEAL Page 6 of 7 State Stormwater Management Systems Permit No. SW8 991003 Modification Certification Requirements; 1. The drainage area to the system contains approximately the permitted acreage. 2. The drainage area to the system contains no more than the permitted amount of built -upon area. 3. All the built -upon area associated with the project is graded such that the runoff drains to the system. 4. All roof drains are located such that the runoff is directed into the system. 5. The outlet/bypass structure elevations are per the approved plan. 6. The outlet structure is located per the approved plans. 7. Trash rack is provided on the outlet/bypass structure. 8. All slopes are grassed with permanent vegetation. 9. Vegetated slopes are no steeper than 3:1. 10. The inlets are located per the approved plans and do not cause short- circuiting of the system. 11. The permitted amounts of surface area and/or volume have been provided. 12. Required drawdown devices are correctly sized per the approved plans. 13. All required design depths are provided. �14. All required parts of the system are provided, such as a vegetated shelf, and a forebay. 15. The required system dimensions are provided per the approved plans. cc: NCDENR-DWQ Regional Office New Hanover County Building Inspections Page 7 of 7 N KT #04221 Z State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM This form may he pholocopied for use as an original 1. GENERAL INFORMATION 1. Applicants name (specify the name of the corporation, individual, etc. who owns the project): Wilmington International Airport 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Jon W. Rosborough, Director 3. Mailing Address for person listed in item 2 above: 1740 Airport Boulevard City: Wilmington State: NC Zip: 28405 Telephone Number: (910) 341-4333 4. Project Name (subdivision, facility, or establishment name — should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Wilminaton International Airport T-Hanaar Project - Phase III ��i h ►s / " IL-M " 5. Location of Project (street address): 1740 Airport Boulevard City: Wilmington County: New Hanover 6. Directions to project (from nearest major intersection): Located approximately 1/2 mile north of Kerr Avenue entrance to airport on to the end of easternmost taxi way. 7. Latitude: 34" 16' 02" Longitude: 77" 53' 35" of project 8. Contact person who can answer questions about the project: Name: Jon W. Rosborough Telephone Number: 91 q 341 -4333 11. PERMIT INFORMATION l . Specify whether project is (check one): X New Form SWU-101 Version 3.99 Page 1 of 4 Renewal Modification REVISED 12/28/04 2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the Existing permit number NIA And its issue date (if known) NIA 3. Specify the type of project (check one): X Low Density High Density Redevelop 4. Additional Project Requirements (check applicable blanks): CAMA Major X Sedimentation/Erosion Control General Permit 404/401 Permit Other NPDES Stormwater Information on required state permits can be obtained by contacting the Customer Service Center at 1-877-623-6748. III. PROJECT INFORMATION I In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative (one to two pages) describing stormwater management for the project. Stormwater runoff will be collected and directed to a "d and". Project consists of a new airplane T-Han ar with associated drives and parking areas. 2. Stormwater runoff from this project drains to the Cape Fear River Basin. 3. Total Project Area: 1,435 Acres 5. How many drainage areas does the project have? 4. Project Built Upon Area: 14.39 % 6. Complete the following information for each drainage area. If there are more than two drainage areas in the project, attach an additional sheet with the information for each area provided in the same format as below. This Proiect TOTAL SITE Basin Information Drains a Area I Drainage Area 2 Receiving Stream Name Smith Creek Smith Creek Receiving Stream Class C-SW C-SW Drainage Area 4.29 AC 1,435 AC Existing Impervious * Area 1.66 AC 204.4 AC Proposed Impervious* Area 0.38 AC 206.5 AC % Impervious* Area total 47.55% 14.39% Impervious* Surface Area Drainage Area 1 Drains a Area 2 On -site Buildings 0.869 AC `-1 t-1 On -site Streets 0 On -site Parking 1.173 ACI 206.5 AC Total Im ervious On -site Sidewalks 0 Other on -site 0 Off -site 0 Total: 2.04 AC <ZyD Total: 206.5 AC * Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas sidewalks, gravel areas, etc. Form SWU-101 Version 3.99 Page 2 of 4 .. � f .- � a J ' �1. . t H •i � .� �� �' - � _ ' r . e' ... ,,. .:f .' _ _ _ � ter: _ 3� � l .. �..r � _' i;1,-. , .! y � � . ' C _' . _ 3 f. y'1 _ _ ... • . F . { .. .l 1' . , r f f . - , .rri .— 1 ! , ' �. .. � � J 1 e 7. How was the off -site impervious area listed above derived? NIA IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS The following italicized deed restrictions and protective covenants are required to be recorded for all subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table listing each lot number, size and the allowable built -upon area for each lot must be provided as an attachment. The following covenants are intended to ensure ongoing compliance with ,slate stormwater management permit number as issued by the Division of Water Quality. These covenants may not be changed or deleted without the consent of the State. No more than square feet ofany lot shall be covered by structures or impervious materials. Impervious materials include asphalt, gravel, concrete, brick, stone, slate or similar material but do not include wood decking or the water surface of swimming pools. Swales .shall not be filled in, piped, or altered except as necessary to provide driveway crossings. 4. Built -upon area in excess of the permitted amount requires a state stormwater management permit modification prior to construction. 5. All permitted runofffrom outparcels or future development shall be directed into the permitted stormwater control system. These connections to the storm water control system shall be performed in a manner that maintains the integrity and performance of the system as permitted. By your signature below, you certify that the recorded deed restrictions and protective covenants for this project shall include all the applicable items required above, that the covenants will be binding on all parties and persons claiming under them, that they will run with the land, that the required covenants cannot be changed or deleted without concurrence from the State, and that they will be recorded prior to the sale of any lot. V. SUPPLEMENT FORMS The applicable state stormwater management permit supplement fonn(s) listed below must be submitted for each BMP specified for this project. Contact the Stormwater and General Permits Unit at (919) 733-5083 for the status and availability of these forms. Form SWU-102 Wet Detention Basin Supplement Form SWU-103 Infiltration Basin Supplement Form SWU-104 Low Density Supplement Form SWU-105 Curb Outict System Supplement Form SWU-106 Off -Site System Supplement Form SWU-107 Underground Infiltration Trench Supplement Form SWU-108 Neuse River Basin Supplement Form SWU-109 Innovative Best Management Practice Supplement Form SWU-101 Version 3.99 Page 3 of 4 1. VI. SUBMITTAL REQUIREMENTS Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ). A complete package includes all of the items listed below. The complete application package should be submitted to the appropriate DWQ Regional Office. Please indicate that you have provided the following required infonnation by initialing in the space provided next to each item. • Original and one copy of the Stormwater Management Permit Application Form • One copy of the applicable supplement form(s) for each BMP • Permit application processing fee of $420 (payable to NCDENR) • Detailed narrative description of stormwater treatment / management Two copies of plans and specifications, including: tCv - Development / Project name - Engineer and firm - Legend -- North arrow - Scale - Revision number & date - Mean high water line - Dimensioned property / project boundary - Location map with named streets or NCSR numbers - Original contours, proposed contours, spot elevations, finished floor elevations - Wetlands delineated, or a note on plans that none exist - Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations - Drainage areas delineated - Vegetated buffers (where required) VII. .AGENT AUTHORIZATION If you wish to designate authority to another individual or firm so that they may provide information on your behalf, please complete this section. J. Phillip Norris, P.E. Designated agent (individual or firm): Norris, Kuske & Tunstall Consulting Engineers, Inc. Mailing Address City: Wilm 902 Market Street Phone: (910) 343-9653 VIH. APPLICANT'S CERTIFICATION State: NC Zip: 28401 Fax: (910) 343-9604 I, (print or type name of person listed in General Information, item 2) Jon W. Rosborough, Director __ , Certify that the information included on this permit application form is, to the best of my knowledge, correct and that the project will be constructed in conformance with the approved plans, that the required deed restrictions and protective covenants will be recorded, thq proposed project complies with the requirements of 15A NCAC 2H.1000. r1 j Signature: Form SWU-101 Version 3.99 Page 4 of 4 Date: / ilo NKT U4221 Permit No. (To be provided by IbW ?� State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT' APPLICATION FORM EXTENDED DRY DETENTION BASIN SUPPLEMENT This form may be photocopied far use as an original. DWQ Stormwater Management Plan Review: A complete stormwater management plan submittal includes a dry detention basin supplement for each basin, design calculations, plans and specification showing all basin and outlet structure details, and a fully executed operation and maintenance agreement. L PROJECT INFORMATION (Please complete the following information): Project Name:Wilmin ton International Airport T-Hangar Project, Phase III Contact Person: J, Phillip Norris, PE phone Number: 910-343-9653 For projects with multiple basins, specify which basin this worksheet applies to: N/A Design Storm: _ 1 _ (Please choose either the 1 yr, 24 hr storm, or the I " storm) Drainage Area: 186,853 square feet Built -upon Area: 88,840 square feet Required Volume: 9,037 cubic feet SHWT elevation: 16.5 FMSL Basin Dimensions: Basin is not rectangular Bottom Elevation: 18.5 feet, MSL Area: N/A fl long x N/A fl wide = 3,138 fl5 Storage Elevation. 20.0 feet, MSL Area: N/A fl long x N/A ft wide= 9,106 fly Detention Volume Provided: 9,183 cubic feet Sediment Storage Provided: 1,810 cubic feet (Equivalent to 20% of the (leteirtion volute) Drawdown Onfce: 1 " pipe (Please indicate size and tyl)e of orifice) Additional BMP to achieve 85% TSS (check one): ,VGrassed swale 0 Vegetated Filter 0 Other Permit No. (7o be provided by DJVQ) II. REQUIRED 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 Section 15A 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 written justification. a. The basin captures the runoff from the 1 year, 24 hour storm and releases it over a period of 48 hours b. OR the basin captures the runoff from the 1 inch storm and allows it to draw down over a period of 2-5 days. C. The minimum flow length ratio is 3:1, L.W. Basin sideslopes are no steeper than 3:1. C. A small permanent pool has been provided at the outlet to reduce clogging. Cleanout access has been provided, sufficient for heavy equipment. A drain has been provided which will completely empty the basin for cleanout Sucient volume has been provided for any local government peak flow requirements. ffi If the basin was used during construction as a sediment basin or trap, it must be cleaned out to design specifications prior to operation as a dry detention basin. A vegetation plan has been prepared by a N.C. licensed professional. Consideration must be given to the grasses specified due to the frequent inundation. The basin must be stabilized within 14 days of construction. 1. The design provides for the sediment storage in addition to the detention volume that is equal to 20% of the detention volume. Inlet and outlet channels have been protected from scour during high flows from large storms. In areas of easily erodible soils, an additional plunge pool at the inlet has been provided, or riprap is used as an energy dissipator. A forebay to capture sediment is recommended to make cleanout easier. p The basin is located in uncompacted natural soils. The seasonal high water table is located at least 1 foot below the bottom of the extended dry detention basin. n additional BMP (such as a swale or vegetated filter) has been designed to operate in conjunction with this dry detention basin to meet the required minimum 85% TSS removal. Permit No. (To be provided by DIYQ) III. EXTENDED DRY DETENTION OPERATION AND MAINTENANCE AGREEMENT The extended dry detention system is defined as the dry detention basin, forebay, and the required additional BMP. This system (check one) 0 does Adoes not incorporate a vegetated filter. This system (check one) 0 does Xdoes not incorporate non-integrated pretreatment. Maintenance activities shall be performed as follows: 1. All grassed areas of the basin shall be mowed at least twice annually, more frequently as needed. 2. Debris must be removed from the basin, outlet and orifice whenever it accumulates or at least twice annually. 3. Annually- inspect the basin after a rain event to ensure it is functioning properly. 4. Repair any erosion of the side slopes and around the inlets and outlet immediately. 5. Accumulated sediment shall removed if it has reduced the available volume to 75% of the original depth. 6. The emergency spillway shall be kept in good working order. 7. Woody vegetation shall be removed from the banks. 8. Any areas of the system found to be deficient shall be repaired or replaced to design standards. 9. Written records of the inspections and maintenance activities shall be kept on file. I acknowledge and agree by my signature below that I am responsible for the performance of the above maintenance procedures. I agree to notify DWQ of any problems with the system or changes in the name of the project, responsible party, or address. Jon W Rosborough Print name: Wilmington International AirportTitle: Director Address: 1740 Airport Blvd Wilmingt.on,_NC 28405 _ Phnne- (910) 341-4333 Fnx- (910)�341-4365 Signati Date: /Z - Z4 - _0 4 I, _ - �,r�4L h.C?>JL0M4 N _ _ � , a Notary Public for the State of `t-t,- 0&,-o No a, County Of `per W14A ND ye r do hereby certify that rou h ersonally appeared before me this the c2%a _ day of 2z0q, and acknowleedge the due execution of the forgoing dry detention basin maintenance requirements. Wk&ygoffp,,Khand and official seal, F /s My Commission expires f • s • _ 5 � f � _� i. �-. i s - r . ti,,l �w ..i 2 al �. `., . � .. -- ,• ti SWALE MAINTENANCE REQUIREMENTS Project Name Wilmington International Airport T-Hangar Project —Phase III Project No. Responsible Party: Jon W. Rosborough, Director Phone No Address: 1740 Airport Boulevard Wilmington, NC 28405 NKT #04221 910-341-4333 1. Mowing will be accomplished as needed according to the season. Grass height will not exceed 6" at any time. 2. Swales will be inspected monthly or after every runoff producing rainfall event for sediment buildup, erosion, and trash accumulation. 3. Accumulated sediment and trash will be removed as necessary. Swales will be reseeded or sodded following sediment removal. 4. Eroded areas of the swales will be repaired and reseeded. Swales will be revegetated as needed based on the monthly inspections. 5. Catch basins, curb cuts, velocity reduction devices, and piping will be inspected monthly or after every runoff producing rainfall event. Trash and debris will be cleared away from grates, curb cuts, velocity reduction devices, and piping. I acknowledge and agree by m signature below that I am responsible for the performance of the above maintenance orocedures��f i Signature Jon W1 Rosborough, Date Ig � U� North Carolina De par.trnent of Environment and Natural Resources Division of Water Quality Wilmington Regional Office Michael F. Easley, Governor William G. Ross, Jr., Secretary March 9.2001 Mr. ,Ion W. Rosborough, Acting Airport Director Wilmington International Airport 1740 Airpol-t Blvd. Wilmington, NC 25405 Dear Mr. Rosborough: �� tl NCDENR ENVIRONMENT ANo NATURAL RESOURCES Subject: Permit No. SWS 991003 Modification Wilmington International Airport T-Hangar Project Low Density Stormwater Project New Hanover County The Wilmington Regional Office received a complete Stormwater Management Permit Application for Wilmington International Airport T-Hangar Project on February 12. 2001. 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. SWS 991003 Modification dated March 9, 2001, for the construction of Wilmington International Airport T-Hangar Project. This permit shall be effective from the date of issuance until rescinded and shall be subject to the conditions and limitations as specified therein, and does not supercede any other agency permit that may be required. 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 2761 1-7447. 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 either Noelle Lutheran or me at (910) 395-3900. Sincerely, - Rick Shiver - Water Quality Regional Supervisor RSS/:nml S:IWQSISTORMWATIPERMIT1961102.MAR cc: Phil Norris, P.E. Ton), Roberts, New I-lanover County Inspections Noelle Lutheran Wilmington Regional Office Central Files Beth Easley 127 Cardinal Dr. Ext., Wilmington, North Carolina 28405 'telephone 910-395-3906 FAX 910-350-2004 An Equal Opportunity Affirmative Action Employer 50'%, recycled110%, post -consumer paper State Stormwater Management Systems Permit No, SW8 991003 Modification STATE OF NORTH CAROLINA DEPARTMENT OF ENVH2ONMENT AND NATURAL RESOURCES DIVISION OF WATER QUALITY STATE STORMWATER MANAGEMENT PERMIT LOW DENSITY DEVELOPMENT In accordance with the provi lions of Article 21 of Chapter 143, General Statutes of North Carolina as amended, and other applicable Latins, Rules and Regulations PERMISSION IS HEREBY GRANTED TO N'ilntington Internatio►ral Airport Wilmington International Airport T-Hangar Project New Hanover County FOR THE construction, operation and maintenance of 30% low density development in compliance with the provisions of 15A NCAC 214.1000 (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 for Wilmington International Airport T-Hangar Project. The Permit shall be effective from ttie date of issuance until rescinded and shall be subject to the following specific conditions and limitations: I. DESIGN STANDARDS I . This permit covers the construction of 89,298 square feet of built -upon area. ?. The overall tract built -upon area percentage for the project must be maintained at 30%, as required by Section .1005 of the stormwater rules. 3. Approved plans and specifications for projects covered by this permit are incorporated by reference and are. enforceable parts of the permit. 4. The only runoff conveyance systems allowed will be vegetated conveyances such as swales with minimum side slopes of 3:1 (H.V) as defined in the stormwater rules and approved by the Division. No piping is allowed except: a. That minimum amount necessary to direct runoff beneath an impervious surface such as a road. b. That minimum amount needed under driveways to provide access. Unless specified elsewhere, permanent seeding requirements for the swales must follow the guidelines established in the North Carolina Erosion and Sediment Control Planning and Design Manual. State Stormwater Management Systems Permit No. SW8 991003 Modification 7. Roof drains must terminate at least 30' from the Mean High Water line. 11. SCHEDULE OF COMPLIANCE Projects covered by this permit will maintain a minimum 30 foot wide vegetative buffer between all impervious areas and surface waters. 2. The permittee is responsible for verifying that the proposed built -upon area does not exceed the allowable built -upon area. 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 awritten 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. 4. Prior to the sale of this project, in whole or in part, the following deed restrictions must be recorded with the Office of the Register of Deeds and submitted to DWQ: "Construction of additional built -upon area in excess of 89,298 square feet will require a permit modification." b. "Construction of additional impervious areas such that low density requirements are no longer met must be submitted to DWQ and a permit modification must be issued prior to construction. An engineered system will be required to collect and treat the runoff from all built -upon area associated with the project, including that area permitted under the low density option." "Filling in or piping of any vegetative conveyances (ditches, swales, etc.) associated with this development, except for average driveway crossings, is strictly prohibited by any persons." d. "A minimum of 3R' of vegetated buffer area shall be provided between surface waters and all impervious surfaces."' Filling in or piping of any vegetative conveyances (ditches, swales, etc.) associated with the permitted development, except for average driveway crossings, is strictly prohibited by any persons. 6. Projects within CAMA's Area of Environmental Concern (AEC) are subject to a reduction of the permitted amount of built -upon area due to CAMA jurisdiction within the AEC. A cop), of the recordedrestrictions must be received by this Office within 30 days of the date of sale. 8. The following items will require a modification to the permit. Revised plans, specifications and calculations must be permitted prior to the permittee beginning construction on the modification: 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, acquisition, or sale of the project area. The project area is defined as all property owned by the permittee, for which Sedimentation and Erosion Control Plan approval was sought. f. Filling in, altering or piping any vegetative conveyance shown on the approved plan. State Stormwater Mana-ement Svstenis Permit No. S\V8 991003 Modification 9. The Director may determine that other revisions to the project should require a modification to the permit. 10. Swales and other vegetated conveyances shall be constructed in their entirety, vegetated, and be operational for their intended use prior to the construction of any built -upon surface. l I During construction, erosion shall be kept to a minimum and any eroded areas of the swales or other vegetated conveyances will be repaired immediately. 12. The permittee shall at all times provide the operation and maintenance necessary to operate the permitted stormwater management systems at optimum efficiency to include: a. Inspections b Sediment removal C. Mowing, and revegetating of the side slopes. d. Immediate repair of eroded areas. e. Maintenance of side slopes in accordance with approved plans and specifications. 13. Within 30 days of completion of the project, the permittee shall certify in writing that the project has been constructed in accordance with the approved plans. 14. The permittee shall submit all information requested by the Director or his representative within the time frame specified in the written information request. III. GENERAL CONDITIONS Failure to abide by the conditions and limitations contained in this permit may subject the Permittee to an enforcement action by the Division of Water Quality, in accordance with North Carolina General Statutes 143-215.6A to 143-215.6C. 2. The permit issued shall continue in force and effect until revoked or terminated. The permit may be modified, revoked and reissued or terminated for cause. The filing of a request for a permit modification, revocation and reissuance, or termination does not stay any permit condition. 4. The issuance of this permit does not prohibit the Director from reopening and modifying the permit, revoking and reissuing the permit, or terminating the permit as allowed by the laws, rules, and regulations contained in Title 15A of the North Carolina Administrative Code, Subchapter 2H.1000; and North Carolina General Statute 143-215.1 et. al. The permit is not transferable to any person except after notice to and approval by the Director. The Director may require modification or revocation and reissuance of the permit to change the name and incorporate such other requirements as maybe necessary. A formal permit request must be submitted to the Division of Water Quality accompanied by the appropriate fee, documentation from both 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. 6. The permittee grants permission to DENR Staff to enter the property for the purpose of inspecting all components of the stormwater management facility. 16 State Storinwater Management Systems Permit No. SW 99100; Modification 7. The permittee shall notify the Division of any name, ownership or mailing address changes within 30 days. 8. The issuance of this permit does not preclude the Permittee from complying with any and all statutes, rules, regulations, or ordinances which may he imposed by other government agencies (local, state and federal) which have jurisdiction. Permit issued this the 9th day of March, 2001. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION --- _ ----------- Kerr T. Stevens, Director Division of Water Quality By Authority of the Environmental Management Commission Permit Number SW8 991003 Modification A A&K #00196 9 0\ 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): Wilmington International Airport 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Jon W. Rosborough, Acting Airport- Director _ T 3. Mailing Address for person' listed in item 2 above: 1740 Airport Blvd. City: Wilmington State: NC Zip: 28405 Telephone Number: (910) 3434333 4. Project Name (subdivision, facility, or establishment name — should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Wilmington International Airport T-Hangar Project - Phase 11 5. Location of Project (street address): 1740 Airport Blvd. City: Wilmington _ _ County: New Hanover 6. Directions to project (from nearest major intersection): pp mile north of Kerr Avenue entrance io airport on to the end of eastermost Located a roximatel 1/2 — _ taxi way. 7. Latitude: 340 16' 02" Longitude: 770 53' 35" of project 8. Contact person who can answer questions about the project: Name: Jon W. Rosborough Telephone Number; (910) 343-4333 11. PERMIT INFORMATION I , Specify whether project is (check one) X New Form SWU-101 Version 3.99 Page 1 of 4 Renewal Modification 2. If this application is being submitted as the result of a renewal or modification to an existing permit, list_ they Existing permit number NIA And its. issue date (if known) NIA; . , 3. Specify the type of project (check one): X Low Density High Density Redevelop General Permit _ Other 4. Additional Project Requirements (check applicable blanks): CAMA Major X Sedimentation/Erosion Control 404/401 Permit NPDES Stormwater Information on required state permits can be obtained by contacting the Customer Service Center at 1-877-623-6748. III. PROJECT INFORMATION In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative 1' (one to two pages) describing stormwater management for the project,,- Stormwater nutoff will be collected by swales which will direct the stormwater to an existing storm sewer; system, Project consists of new ai lane T-Hanar with associated drives and parlcin areas. 2. Stormwater runoff from this project drains to the Cape Fear River Basin. 3. Total Project Area: 1,435 4. Project Built Upon Area: 14.30 % 5. How many drainage areas does the project have? 1 6. Complete the following iwf n-nation'for each drainage area. Ifthere are more than two.diainage areas in the project, attach an additional sheet with the information for each area provided in the same format as below. Basiri l.fi orination ak i} QU," ''' s; . '' .F',Draina a Area l M. ''.' Receiving Stream Name Smith Creek. Receiving Stream Class C-SW Drainage Area 1,435 acres Existing Impervious * Area 204.4 acres Proposed Impervious* Area 0.87 acres % Impervious* Area (totaly 14.30. Im""`erviois*,Srs'rface Drains e.Area 1 S, "Draira e.Area'2, '' ., On -site Buildings 0.36 acres On -site Streets 0.25 acres On -site Parking 0.26 acres On -site Sidewalks 0 Other on -site 0 Off -site 0 �Q Total: 0.87 acres 1, a,G Total: Z � S ; * Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas sidewalks, gravel areas, etc. Form SWU-101 Version 3.99 Page 2 of 4 It 7. How was the off -site impervious area listed above derived? NIA IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS The following italicized deed restrictions and protective covenants are required to be recorded for all subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table listing each lot number, size and the allowable built -upon area for each lot must be provided as an attachment. The following covenants are intended to ensure ongoing compliance with state stormwater management permit number as issued by the Division of Water Quality. These covenants may not be changed or deleted without the consent of the State. No more than square feet of any lot shall be covered by structures or impervious materials. Impervious materials include asphalt, gravel, concrete, brick, stone, slate or similar material but do not include wood decking or the water surface ofswimming pools. Swales shall not be filled in, piped, or altered except as necessary to provide driveway crossings. 4. Built -upon area in excess of the permitted amount requires a state stormwater management permit modification prior to construction. All permuted runoff from outparcel s or future development shall be directed into the permitted stormwater control system. These connections to the stormwater control system shall be performed in a manner that maintains the integrity and performance of the system as permitted. By your signature below, you certify that the recorded deed restrictions and protective covenants for this project shall include all the applicable items required above, that the covenants will be binding on all parties and persons claiming under them, that they will run with the land, that the required covenants cannot be changed or deleted without concurrence from the State, and that they will be recorded prior to the sale of any lot. ' V, SUPPLEMENT FORMS The applicable state stormwater management permit supplement form(s) listed below must be submitted for each BMP specified for this project. Contact the Stormwater and General Permits Unit at (919) 733-5083 for the status and availability of these forms. Form SWU-102 Form SWU-103 Form SWU-104 Form SWU-105 Form SWU.-106 Form SWU-107 Form SWU-108 Form SWU-109 Wet Detention Basin Supplement Infiltration Basin Supplement Low Density Supplement Curb Outlet System Supplement Off -Site System Supplement Underground Infiltration Trench Supplement Neuse River Basin Supplement Innovative Best Management Practice Supplement Form SWU-101 Version 3.99 Page 3 of 4 Vl. SUBMITTAL REQUIREMENTS Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ). A complete package includes all of the items listed below. The complete application package should be submitted to the appropriate DWQ Regional Office. Please indicate that you have provided the following required information by initialing in the space provided next to each item. • Original and one copy of the Stormwater Management Permit Application Form • One copy of the applicable supplement form(s) for each BMP • Permit application processing fee of $420 (payable to NCDENR) • Detailed narrative description of stormwater. treatment 1 management • Two copies of plans and specifications, including: - Development 1 Project name - Engineer and firm - Legend - North arrow - Scale - Revision number & date - Mean high water. line - Dimensioned property / project boundary - Location map with named streets or NCSR numbers . - Original contours, proposed contours, spot elevations, finished floor elevations - Wetlands delineated, or a note on plans that none exist - Existing drainage (including off -site), drainage easements, pipe sixes, runoff calculations - Drainage areas delineated - Vegetated buffers (where required) Vll. AGENT AUTHORIZATION If you wish to designate authority to another individual or firth so that they may provide information on your behalf, please complete this section. J. Phillin Norris. P. E. Designated agent (individual or firm): Andrew & Kuske Consulting Engineers, Inc. Mailing Address: 902 Market Street City: _Wilmington . _ _ State: NC Zip: 28401 Phone: 910 343-9653 VIII. APPLICANT'S CERTIFICATION Fax: (910) 343-9604 - 1, (print or type name of person listed in General Information, item 2) Jon W. Rosborough r, Certify that the information included on this permit application form is, to the best of my knowledge, correct and that the project will be constructed in conformance with the approved plans, that & required deed restrictions and protective covenants will be recorded, and that the proposed project complies with the requirements of 15A NCAC - 2H.1000. Date: Ih)04 ' Form SWU-101 Version 3.99 Page 4 of 4 A&K #00196 Permit No. 3w9 96 //6 a2 '1) (to he provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM LOW DENSITY SUPPLEMENT This form may be photocopied for use as an original A Iow density project is one that meets the appropriate criteria for built upon area and transports stormwater runoff primarily through vegetated conveyances. Low density projects should not have a discrete stormwater collection system as defined by 15A NCAC 2H .1002(18). Low density requirements and density factors can be found in 15A NCAC 2H .1005 through .1007. I. PROJECT.INFORMATION Project Name: Wilmington International Airport T-Hangar Project - Phase I1 Contact Person: Jon W. Rosborough Phone Number: (910 ) 343-4333 Number of Lots: N/A Allowable Built Upon Area Per Lot*: N/A *If lot sizes are not uniform, attach a table indicating the number of lots, lot sizes and allowable built upon area for each lot. The attachment must include the project name, phase, page numbers and provide area subtotals and totals. H. BUILT UPON AREA See the Stormwater Management Permit Application for specific language that must be recorded in the deed restrictions for all subdivisions. For uniform lot sizes, complete the following calculation in the space provided below where: • SA Site Area - the total project area above Mean High Water. Wetlands may be excluded when the development results in high density pockets. • DF Density Factor - the appropriate percent built upon area divided by 100. • RA Road Area - the total impervious surface occupied by roadways. • OA Other Area - the total area of impervious surfaces such as clubhouses, tennis courts, sidewalks, etc. • No. Lots - the total number of lots in the subdivision. • BUAILot - the computed allowable built upon area for each lot including driveways and impervious surfaces located between the front lot line and the edge of pavement. Form SWU-104 Rev 3.99 Page 1 of 2 Calculation: (SA x DF) - RA - OA_ = BUA No. Lots Lot See attached calculations. II1. REQUIRED ITEMS CHECKLIST Initial in the space provided to indicate that the following requirements have been met and supporting documentation is provided as necessary. If the applicant has designated an agent on the Stormwater Management Permit Application Form, the agent may initial below. Applicantitials a. A 30 foot vegetative buffer is provided adjacent to surface waters. Projects in the Neuse River basin may require additional buffers. N/A b. Deed restriction language as required on form SWU-101 shall be recorded as a restrictive covenant. A copy of the recorded document shall be provided to DWQ within 30 days of platting and prior to sale of any lots. c. Built upon area calculations are provided for the overall project and all lots. d. Project conforms to low density requirements within the ORW AEC (if applicable). [15A NCAC 2H .1007(2)(b)3 Form SWU-104 Rev 3.99 Page 2 of 2