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HomeMy WebLinkAboutSW7080611_HISTORICAL FILE_20080817NORTH CAROLINA Department of Environmental Qual 2 N d STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW :Zz2UZad DOC TYPE ❑ CURRENT PERMIT ❑ APPROVED PLANS HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE YYYYMMDD 0w�o Michael F. Easley, Governor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources Colem H. Sullins, Director Division of Water Quality August 19, 2008 Craven County Regional Airport Authority Attn: Mr. Tom Braaten PO Box 3258 New Bern, NC 28564 Subject Stormwater Review SW7080611 2008 Parking Lot Expansion, Terminal Drive Craven County Dear Mr. Braaten: This office received a Coastal Stormwater permit application for the subject project on June 18, 2008. After reviewing our stormwater files, I realized that the proposed expansion is located in the same drainage basin as a previous project. Our office issued Stormwater Permit SW7990825 on September 30, 1999 for the terminal upgrades, a parking lot and a wet pond. Since this permit expires on September 30, 2009, and because the current project drains to the same wet pond, it seems appropriate to rescind the existing permit and issue this new permit to cover the entire drainage basin. The LPA Group did a really good job in providing a detailed stormwater package for the proposed project. A preliminary review of your project indicates that before a State Stormwater permit can be issued, the following additional information is needed: 1. Revise stormwater narrative to explain merging of existing & new projects into same drainage basin. 2. Revise submerged orifice detail; provide structural support, adjust elevation, revise orifice diameter to 3-inches. The above requested information must be submitted to this office prior to September 19, 2008, or your application will be returned as incomplete. The return of this project will necessitate resubmittal of all required items including a new application fee. If you need additional time to complete the application package, please mail or fax your request to this office and include any reason(s) for the time delays. You should also be aware that the Stormwater Rules require that the permit be issued prior to any development activity. Construction without a permit is a violation of 15A NCAC 21-1.1000 and North Carolina General Statute 143-215.1 and may result in civil penalties of up to $25,000 per day. If you have questions, please feel free to contact me at (252) 948-3919, or you can send a message to: bill.moore@ncmafl.net. Si%n�ce/re�l1`, William J. Moore Environmental Engineer Washington Regional Office cc: yhe LPA Group of NC ashington Regional Office Internet: WwW.ncwatCrqualil y0 One North Carolina Division of Water Quality phone (252 946�4RI w Carolina 943 Washington Square Mall Fax ( (25 946-92 8 Naturally // Washington, NC 27889 al�uL al y THE LPA GROUP of North Carolina, p.a. Transportation Consultants 5000 FALLS OF NEUSE ROAD ■ SUITE 304 ■ RALEIGH, NORTH CAROLINA 27609 ■ 919-954-1244 ■ FAX 919-954-1345 August 22, 2008 Mr. Bill Moore NCDENR, Division of Water Quality Washington Regional Office 943 Washington Square Mall Washington, North Carolina 27889 Re: Craven County Regional Airport Terminal Parking Lot Expansion Dear Bill: AUG 2 5 2008 DWQ'W, RO Enclosed please find two (2) copies of sheet DD-1 for the above referenced project. Sheet DD-1 has been revised to show changes to the submerged orifice detail. The detail has been changed to include a steel support bar and clamp. The detail has also been changed to show a 3 inch hole drilled in the bottom of the orifice, and a new top elevation. In addition, the length of the top section of PVC pipe was changed to 6 inches. Also enclosed are two (2) copies of the revised Drainage Narrative. The Narrative was revised to include an explanation of why the permit for the existing wet detention pond (SW7990825) should be rescinded and a new permit should be obtained to cover the existing pond, as well as the proposed expansion, as we previously discussed. If you have any questions or need additional information, please do not hesitate to call. Sincerely, THE LPA GROUP of North Carolina, p.a. Jason L. Elliott, El Aviation Design Enclosures Member of THE LPA GROUP INCORPORATED ATUWTA ■ BALTIMORE • BATON ROUGE • CHARLOTTE • COLUMBIA • GREENSBORO ■ IRVINE ■ JACKSONVILLE ■ KENNESAW • KNOXVILLE • LITTLE ROCK M[LEAN • MOBILE ■ NASHVILLE ■ OCEAN SPRINGS ■ ORLANDO • RALEIGH • SARASOTA • TALIAHASSEE ■ TAMPA ■ WEST PALM BEACH a' STORMWATER MANAGEMENT PERMIT RECEEVED FOR TERMINAL PARKING LOT EXPANSION AT AUG 2 5 2008 CRAVEN COUNTY REGIONAL AIRPORT M�yy��/ p Q..��i�i �d U 7 R0 PROJECT DESCRIPTION AND PURPOSE This project is being completed to provide additional long-term parking for the terminal building at the Craven County Regional Airport. As a result of the ongoing growth of the airport, more parking is needed to handle the increased traffic. As part of the project, the existing wet detention pond will also be expanded to treat runoff from the ultimate build -out of the parking lot. The project will be split into two phases. The first phase will include the initial portion of the parking expansion and the full expansion of the wet detention pond. Stormwater Permit SW7990825 was issued for the existing wet detention pond on September 30, 1999. The current project will expand the existing pond. The drainage basin, draining to the pond, is the same as the one from the original project, with the addition of new impervious area. For this reason, the previous and current projects should be merged into the same drainage basin. In addition, the original permit, SW7990825, should be rescinded. A new permit is being requested to cover the drainage basin, which drains to both the existing pond and the proposed expansion. EXISTING CONDITIONS This project lies within the Neuse River Basin. The site is located inside the terminal area's Loop Access Road. The road is located next to Scott's Creek. Runoff from this area is drained to the existing wet detention pond. The outlet pipe for the existing pond runs under the Loop Access Road and empties directly into Scott's Creek. Scott's Creek is considered a class SC waterway, with supplemental classifications as Sw (swamp waters) and NSW (nutrient sensitive waters). The area of the project does not contain- and is not adjacent to- any wetland areas. PROPOSED DEVELOPMENT The current phase of development for the Parking Lot Expansion will create an additional 46,762 sq.ft of impervious surface area on the Airport property. Also included in the current phase will be the expansion of the existing wet detention pond to treat the runoff from all future impervious area for the site. Future development in this area includes further expansion of the proposed parking lot. This future development will add an additional 133,455 sq.ft. of impervious area to the drainage basin. STORMWATER QUALITY ANALYSIS Parking Lot Expansion Revised Narrative Craven County Regional Airport August, 2008 0 To provide treatment for the entire buildout of the Parking Lot Expansion project, the existing wet detention pond will be expanded to provide treatment for the development in this area. All areas draining to the pond are located on -site. The total drainage area to the wet detention pond is 440,524 sq.ft (10.1 acres). The total impervious drainage area at the completion of the full parking expansion will be 288,667 sq.ft (6.6 acres), which is 65.5% of the total area. The wet detention pond has been designed to treat the first 1 inch of rainfall, in accordance with the NCDENR Stormwater BMP Manual. Due to the lack of space to include a vegetative filter strip, the wet detention pond has been designed for 90% TSS removal. The pond will have an average depth of 3.77 feet. The treatment volume provided by the pond is 27,002 cu.ft (the minimum required volume is 23,611 cu.ft). The surface area at the permanent pool elevation is 35,207 sq.ft (the minimum required surface area is 29,038 sq.ft). Runoff from the area will first enter a forebay that will be used for pre-treatment to slow down the velocity and allow settlement of large sediment particles before entering the main detention basin. The bottom elevation of the proposed forebay is 5.0 feet. The volume of the forebay at the permanent pool elevation is 18.5% of the entire volume of the permanent pool. The stormwater would then pass over a 50 foot wide spillway, which would have an elevation of 9.5 feet, and into the main pond. The bottom elevation of the proposed main pond is 2.0 feet. The top of the pond is approximately 12.5 feet. The pond would have a permanent pool elevation of 9.5 feet. The permanent pool will be maintained at or below this elevation by a 3 inch, submerged orifice. The orifice is sized to release the volume of the temporary pool over a period of 2.8 days. Runoff from the area would build to an elevation of 10.2 feet in the forebay and main pond before draining through a rectangular 12 inch by 6 inch orifice opening. Through the rectangular opening, the stormwater would enter the proposed riser structure and exit through the 24 inch pipe which runs under the Loop Access Road. The rectangular orifice is used to keep the post -development discharge below the pre -development discharge. The outlet pipe empties directly into Scott's Creek. The riser structure will also have an over -flow weir at an elevation of 11.0 feet. The overflow weir will consist of 4 foot by 8 inch rectangular openings cut into three sides of the structure. This weir is to release extra stormwater during larger storm events. The entire drainage area was analyzed using XP-SWMM software. The area was modeled using the SCS Method to calculate runoff. The area was modeled using both the existing conditions and the proposed design at full buildout. The existing conditions were modeled in order to keep the post -development discharge below or equal to the pre -development discharge for the 1-yr, 24 hr storm. The 1-yr discharge from the pond was 1.26 cfs for the existing conditions. The proposed design yielded a 1-yr discharge of 1.14 cfs. The maximum pond elevation for the 1-yr storm was 10.69 feet. The drainage for the site was designed to accommodate runoff from a 10-yr storm event. The proposed design was analyzed using the 10-yr storm event. The pond elevation was also checked using the 50-yr and 100-yr storm events to ensure that the overflow weir was enough to keep it from overtopping under these conditions. Using the XP-SWMM software, the pond elevation rose to 11.43 feet during the 10-yr storm. This elevation leaves approximately one foot of freeboard. The 50-yr storm rose to an elevation of 11.88 feet and the 100-yr storm rose to an Parking Lot Expansion 2 Craven County Regional Airport Revised Narrative August, 2008 elevation of 12.18 feet, which is below the pond's top elevation. The lowest point along the edge of pavement of the access road adjacent to the pond is 12.84 feet. The proposed pond is adequately sized to provide treatment for the first 1 inch of runoff from the 10-yr storm event, as well as hold the additional volume from the 100-yr storm without overtopping. Graphs for the pond, existing and proposed pipes, and the outlet structure are enclosed for the 10-yr storm. Graphs of the pond elevations are also enclosed for the 1-yr, 50-yr, and 100-yr storms. Parking Lot Expansion 3 Craven County Regional Airport Revised Narrative August, 2008 Michael F. Easley, Governor Q William G. Ross Jr., Secretary 0 North Carolina Department of Environment and Natural Resources CO Coleen H. Sullins, Director p Division of Water Quality Chuck Wakild, P.E., Deputy Director Division of Water Quality June 12, 2008 Mr. John H. Price, Jr. Craven Regional Airport Authority 1501 Airport Road New Bern, INC 28560 Subject:: Stormwater Permit No. SW7990825 Craven Airport - Parking Expansion Craven County Dear Mr. Price: The Division of Water Quality issued a Coastal Stormwater Management Permit, Number SW7990825 for Craven Airport - Parking Expansion on 9/30/1999. This permit expires on 9/30/2009. Section .1003(h) of 15 A NCAC 2H .1000 (the stormwater rules) requires that applications for permit renewals shall be submitted 180 days prior to the expiration of a permit and must be accompanied by a processing fee, which is currently set at $505.00. If this is still an active project please complete and submit the enclosed renewal application in a timely manner. If this project has not been constructed and a permit is no longer needed, please submit a request to have the permit rescinded. If you have sold the project, or are no longer the permittee, please provide the name, mailing address and phone number of the person or entity that is now responsible for this permit. Enclosed is a form for change of ownership, which should be completed and submitted if the property has changed hands. Your permit requires that upon completion of construction and prior to operation of the permitted treatment units a certification of completion be submitted to the Division from an appropriate designer for the system installed. This is to certify that the permitted facility has been installed in accordance with the permit,,the approved plans, specifications and supporting documentation. Please include a copy of the certification with your permit renewal request and processing fee. Enclosed is a copy of a sample certification. You should be aware that failure to provide the Designer's Certification and the operation of a stormwater treatment facility without a valid permit, are violations of NC General Statute 143-215.1 and may result in appropriate enforcement action including the assessment of civil penalties of up to $10,000 per day. If you have any questions, please feel free to contact me or a member of the coastal stormwater staff with DWQ at 252-946-6481. Enclosures cc: ✓The. LPA Group of NC Washington Regional Office North Carolina Division of Water Quality 943 Washington Square Mall Washington, NC 27889 cer ly, A``A dge, Regional Supervisor Surface Water Protection Section Washington Regional Office Internet: wv wmcwatcraualitv.org Phone (252) 946-6481 . Fax (252) 946-9215 NorthCarolina Naturally An Equal Opportunity/Affirmative Action Employer — 50% Recycled110% Post Consumer Paper O� W A7'f Michael F. Easley, Governor 0 William G. Ross Jr., Secretary G North Carolina Department of Environment and Natural Resources CO r Coleen H. Sullins, Director Division of Water Quality Chuck Wakild, P.E., Deputy Director Division of Water Quality June 12. 2008 Mr. John H. Price, Jr. Craven Regional Airport Authority 1501 Airport Road New Bern, NC 28560 Subject:: Stormwater Permit No. SW7990825 Craven Airport - Parking Expansion Craven County Dear Mr. Price: The Division of Water Quality issued a Coastal Stormwater Management Permit, Number SW7990825 for Craven Airport - Parking Expansion on 9/30/1999. This permit expires on 9/30/2009. Section .1003(h) of 15 A NCAC 2H .1000 (the stormwater rules) requires that applications for permit renewals shall be submitted 180 days prior to the expiration of a permit and must be accompanied by a processing fee, which is currently set at $505.00. If this is still an active project please complete and submit the enclosed renewal application in a timely manner. If this project has not been constructed and a permit is no longer needed, please submit a request to have the permit rescinded. If you have sold the project, or are no longer the permittee, please provide the name, mailing address and phone number of the person or entity that is now responsible for this permit. Enclosed is a form for change of ownership, which should be completed and submitted if the property has changed hands. Your permit requires that upon completion of construction and prior to operation of the permitted treatment units a certification of completion be submitted to the Division from an appropriate designer for the system installed. This is to certify that the permitted facility has been installed in accordance with the permit, the approved plans, specifications and supporting documentation. Please include a copy of the certification with your permit renewal request and processing fee. Enclosed is a copy of a. sample certification. You should be aware that failure to provide the Designer's Certification and the operation of a stormwater treatment facility without a valid permit, are violations of NC General Statute 143-215.1 and may result in appropriate enforcement action including the assessment of civil penalties of up to $10,000 per day. If you have any questions, please feel free to contact me or a member of the coastal stormwater staff with DWQ at 252-946-6481. cer ly, A`dge, Regional Supervisor Surface Water Protection Section Washington Regional Office Enclosures cc: The LPA Group of NC ashington Regional Office North Carolina Division of water Quality Internet: www.ncwaterouality ore One 943 Washington Square Mall Phone (252) 946-6481 NorthCarofina Washington, NC 27889 Fax (252) 946-9215 a iry F all y An Equal OpportunitylAffirmative Action Employer -50%Recycled110% Post Consumer Paper �/ yKL ! [L Plans on top of file cabinet ..., OFFICE USE ONLY .., Date Received Fee Paid Permit Ni -a - r.J Q State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLIC Ii0RM � This form may be photocopied for use as an original J t AUG - 2 1999 i I. GENERAL INFORMATION WASNINGION REGIONAL 1. Applicants name (specify the name of the corporation, individual, etc. who 0 CRAVEN Cov-rY /LGG/OivAG 41P_,0o1Z7- 4u-r'Ho2ITy 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Jo}Fn/ H. P2/CL', JR. , Al2Po2i D//2ECTa2 3. Mailing Address for person listed in item 2 above: l 5 o / fl l2 Po 2'T !Loft A , City: /VGw 136712111 State: IV c Zip: Z S 5 !n o Telephone Number: ( Z 5 Z ) t0 3 8 - 659/ 4. Project Name (subdivision, facility, or establishment name -should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): CRlfVEi✓ CovniTA-,2tq)47- 5. Location of Project (street address): 150/ )4-1kPc�P_ 2o,�p City: NE w 13 ekav County: /v C 6. Directions to project (from nearest major intersection): C1ZXVEN Covi✓TY %0E(,w/NA6 A11CP0/t7- — TC2iuin�LfC 7. Latitude: 35' O 1- 2,3Longitude: 776 62 ' 35 of project 8. Contact person who can answer questions about the project: Name: J E`F R E >' A4. jL 11 /t I Telephone Number:( '711/ ) 9 $ 5l - / Z elcf H. PERMIT INFORMATION: 1. Specify whether project is (check one): XNew Renewal Modification Form SWU-101 Version 3.99 Page 1 of 4 2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the existing perm t number and its issue date (if known) 3. Specify the type of project (check one): _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. �II I'-- PROJECT INFORMATION 17—Ifi the'space provided below, surnmarize how stormwater will be treated. Also attach a detailed narrative (one to two pages) describing stormwater management for the project. wEi - po-vo 2. Stormwater runoff from this project drains to the .f/EL> S E River basin. 3. Total Project Area: /D / acres 4. Project Built Upon Area: Z z S % 5. How many drainage areas does the project have?_� 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. Basm`;Informatioa ge �'Dratha Areajl r Drarna eArea2,. n x Receiving Stream Name SG o %'T4" G e r 5 to Receiving Stream Class S C — Swgn . P — r w Drainage Area w / Existing Impervious* Area O. Pro osed Im ervious"Area 2.3 % Impervious* Area (total) 2 2 . Iui "ervrous';Siiiface Area a Iharnage Area 1 f v Drainage Area 2 ?, q On -site Buildings On -site Streets p On -site Parking On -site Sidewalks Other on -site Off -site Total: 2.3 Total: 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 2 7. How was the off -site impervious area listed above derived? 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. 1. 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. 2. 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 of swimming pools. 3. 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 runoff from outparcels 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 (919J 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 Outlet 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 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 information by initialing in the space provided next to each item. Initials • Original and one copy of the Stormwater Management Permit Application Form J n4 14 • One copy of the applicable Supplement Form(s) for each BMP J 114 k- • Permit application processing fee of $420 (payable to NCDENR) J roc I4 • Detailed narrative description of stormwater treatment/management J �1 /S • Two copies of plans and specifications, including: J Ntrc - Development/Project name - Engineer and firm -Legend - North arrow - Scale - Revision number & date - Mean high water line - Dimensioned property/project boundary - Location map with named streets or NCSR numbers - Original contours, proposed contours, spot elevations, finished floor elevations - Details of roads, drainage features, collection systems, and stormwater control measures - Wetlands delineated, or a note on plans that none exist - Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations - Drainage areas delineated - Vegetated buffers (where required) VH. 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. Designated agent (individual or firm): -rHC L.1-W 6 Qo up n-p No rl-4 Ca re f�a Mailing Address: 190f ?)2o L s5/oNAL [yu2T s�Jn: z.o/ City: State: w c- Zip: 27e. o 9 Phone: ( 2/9 ) qs—y_ /Z #// VIII. APPLICANT'S CERTIFICATION Fax: ( 9/r-/ ) /30.5 I, (print or type name of person listed in General Information, item 2) Jy H- H. /0/Z/c E , -)/Z . certify that the information included on this permit application form is, to the best of my knowledge, correct and that the project will be constructed in conformance with the approved plans, that the required deed restrictions and protective covenants will be recorded, and that the proposed project complies with the requirements of 15A NCAC 2H .1000. _ I _ ram\ Signature Date: /-3O` 99 Form SWU-101 Version 3.99 Page 4 of 4 THE LPA GROUP of North Carolina, p.a. Transportation Consultants 4904 Professional Court, Suite 201 Post Office Box 17736 Raleigh, North Carolina 27619 (919) 954-1244 FAX (919) 954-1345 July 29, 1999 Mr. William J. Moore NCDENR Division of Water Quality 943 Washington Square Mall Washington, NC 27889 Re: Craven County Regional Airport Terminal Parking Expansion Dear Mr. Moore: WASHINGTON REGIONAL OFFICE On behalf of the Craven County Regional Airport'!l�u41reTi;y'we,are submitting an application for a stormwater management permit for the above referenced project. This expansion is part of the overall development of a new terminal facility at the Craven C'o'ui ty�Regional Airport. The following documents are enclosed: • Stormwater Management Permit Application (1 original, 1 copy) • Wet Detention Basin Supplement • Processing Fee of $420.00 • Project Narrative • Design Calculations • Plans (2 copies) Currently, the new terminal building is scheduled to open in mid -September. It is the desire of the Authority to complete the parking area expansion concurrently with the September opening of the new passenger terminal building. Thank you in advance for your cooperation and if you have any questions or need additional information, please feel free to call. Sincerely, T LPA GRO P of North Carolina, p.a. ffrey M. Kirby, P.E. Project Engineer Enclosures Member of THE LPA GROUP INCORPORATED ATLANTA, GA • CHARLESTON, SC • CHARLOTrE,NC • CHICAGO, IL • COLUMBIA, SC • GREENSBORO, NC • KNOXVILLE, TN • MOBILE, AL MYRTLE BEACH, SC • PHILADELPHIA, PA 0 RALEIGH, NC • RICHMOND,VA 0 TALLAHA5SE, FL 0 TAMPA, FL Craven County Regional Airport Terminal Parking Lot Expansion Stormwater Management Project Narrative (Revised) D CSC ii iLS III SEP 2 Q WASHINGTON RL310h;kL OFFICE The Craven County Regional Airport, located in New Bern, NC, is expanding the existing parking facilities to accommodate increased traffic at the airport. The proposed site is within the overall terminal development complex. This project will increase the impervious surface area flowing into Scott's Creek, which eventually flows in the Neuse River. Since the impervious surface area is increased, the stormwater runoff will increase, therefore requiring the installation of stormwater management measures. The stormwater management device used to detain the runoff from the proposed site will be a wet detention pond. The wet detention pond will capture the runoff from an area of approximately 10.1 acres. The impervious area is approximately 2.3 acres. The permanent pool will have a depth of 4 feet and a surface area of 8,405 square feet. The forebay area will provide approximately 16% of this volume. A temporary storage volume above the permanent pool has been provided to detain the initial runoff. The temporary storage will be released over a period of 2.4 days through a 3" opening in the outlet structure. The outlet structure of the wet pond has been designed to carry the 25-year storm event without overtopping the shoulder of the loop access road. Runoff will be conveyed to the wet detention pond via drainage pipe and grassed drainage swales. Drainage swales will have side slopes of 4:1. All pipes and drainage swales will outfall into an area above the permanent pool that has a slope of less than 0.5%. This area will provide an area of pre-treatment prior to the runoff getting into the wet detention pond. The outlet structure will consist of an open drop inlet connected to an existing 24" concrete pipe culvert, which flows under the loop access road. Due to the invert of this pipe, the bottom of the pond will be below the pipe invert. Therefore, the pond will have to be pumped in the event the outlet structure needs to be repaired. The wet detention pond will be maintained based on a schedule of monthly, quarterly, semi-annually, and annual procedures. 91799 Page 1 of 1 I Craven County Regional Airport Terminal Parking Lot Expansion Stormwater Management Project Narrative U .\�� U WASHINGTON REGIONAL OFFICE The Craven County Regional Airport, located in New Bern, NC, is expanding the existing parking facilities to accommodate increased traffic at the airport. The proposed site is within the overall terminal development complex. This project will increase the impervious surface area flowing into Scott's Creek, which eventually flows in the Neuse River. Since the impervious surface area is increased, the stormwater .runoff will increase, therefore requiring the installation of stormwater management measures. The stormwater management device used to detain the runoff from the proposed site will be a wet detention pond. The wet detention pond will capture the runoff from an area of approximately 10.1 acres. The impervious area is approximately 2.3 acres. The permanent pool will have a depth of 4 feet and a surface area of 8,405 square feet. The forebay area will provide approximately 16% of this volume. A temporary storage volume above the permanent pool has been provided to detain the initial runoff. The temporary storage will be released over a period of 2.4 days through a 3" opening in the outlet structure. The outlet structure of the wet pond has been designed to carry the 25-year storm event without overtopping the shoulder of the loop access road. The outlet structure will consist of an open drop inlet connected to an existing 24" concrete pipe culvert, which flows under the loop access road. Due to the invert of this pipe, the bottom of the pond will be below the pipe invert. Therefore, the pond will have to be pumped in the event the outlet structure needs to be repaired. The wet detention pond will be maintained based on a schedule of monthly, quarterly, semi-annually, and annual procedures. Permit No. Ito he provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICA FORM i 1OFFICE AUG - 2WET DETENTION BASIN SUPPLEME T Thisform may be photocopiedfor use as an original WASHINGTON REGI OWO DWO Stormwater Management Plan Review: A complete stormwater management plan submittal includes an application form, a wet detention basin supplement for each basin, design calculations, and plans and specifications showing all basin and outlet structure details. I. PROJECT INFORMATION Project Name: C2AvCN covA/-iY 2� Gi�Nst� �i2po2%- 7E2n, tiAc P�2 e� ul. 6y�P. Contact Person: J EFF2E M. K iR R Y Phone Number: f 9 19 ) 9 5 z1-i z Y For projects with multiple basins, specify which basin this worksheet applies to: Al /A elevations Basin Bottom Elevation G. S ft. Permanent Pool Elevation /o• o ft. Temporary Pool Elevation // 3 ft. areas Permanent Pool Surface Area sq. ft. Drainage Area Impervious Area o - / ac. Z 3 ac. (floor of the basin) (elevation of the orifice) (elevation of the discharge structure overflow) (water surface area at the orifice elevation) (on -site and off -site drainage to the basin) (on -site and off -site drainage to the basin) volumes Permanent Pool Volume Z 2, 2/4o cu. ft. (combined volume of main basin and forebay) Temporary Pool Volume 3 7. `(, 2 cu. ft. (volume detained above the permanent pool) Forebay Volume 3. `f '3S cu. ft. (approximately 20% of total volume) Other parameters SA/DA I Diameter of Orifice Design Rainfall Design TSS Removal Z 2 in. /.o in. icy % (surface area to drainage area ratio from DWQ table) (2 to 5 day temporary pool draw -down required) (minimum 85% required) Form SWU-102 Rev 3.99 Page I of 4 <A Footnotes: 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. !'- In the 20 coaHal couniies, the requirement for a vegetative filter may be waived if the wet detention basin is designed to provide 90% TSS removal. The NCDENR BMP manual provides design tables for both 85% TSS removal and 90% TSS removal. III. 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, February 1999) 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. Applicants Initials ^ �K a. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet). J Ml� b. The forebay volume is approximately equal to 20% of the basin volume. µK c. The temporary pool controls runoff from the design storm event. M /Z- d. The temporary pool draws down in 2 to 5 days. /VJ 4 e. If required, a 30-foot vegetative filter is provided at the outlet (include non -erosive flow calculations) it l IG 7 f. The basin length to width ratio is greater than 3:1. -1 wt k g. The basin side slopes above the permanent pool are no steeper than 3:1. J nix_ h. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail). 0 m I< i. Vegetative cover above the permanent pool elevation is specified. �P�zY_ j. A trash rack or similar device is provided for both the overflow and orifice. nit lc k. A recorded drainage easement is provided for each basin including access to nearest right- of-way. J ra le, 1. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified prior to use as a wet detention basin. sEt AM2RArivE in. A mechanism is specified which will drain the basin for maintenance or an emergency. III. WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if one is provided. This system (check one) 0 does Xdoes not incorporate a vegetated filter at the outlet. This system (check one) 0 does R does not incorporate pretreatment other than a forebay. Form SWU-IO2 Rev 3.99 Page 2 of 4 0�-�4-os ll3�D SW 16,200611 (RKT) FINANCIAL RESPONSIBILITY/OWNERSHIP FORM ��--. OO SEDIMENTATION POLLUTION CONTROL ACT/(��a � tt�� No person may initiate any land -disturbing activity on one or more acres as covered ibyfthesActtbesfore�his form and an acceptable erosion and sedimentation control plan have been completed and approved by the Land Quality Section, N.C. Department of Environment and Natural Resources. (PleaseJfypE or2 int and, if the question is not applicable or the e-mail and/or fax infnrmnrh �,, -_ .,,. ._. _.... _.. _.. V,.,c rvin in�nI/ ii/hee biaapn//k.) Part A. ®tltl'V!'i ARU 1. Project Name Craven County Regional Airport, Parkin Lot Expansion 2. Location of land -disturbing activity: County Craven City or Township New Bern Highway/Street Terminal Road Latitude 350 04' 37.5" N Longitude 77' 01' 58.4" W 3. Approximate date land -disturbing activity will commence: November 2008 4. Purpose of development (residential, commercial, industrial, institutional, etc.): Airport / Commercial 5. Total acreage disturbed or uncovered (including off -site borrow and waste areas): 5 Acres 6. Amount of fee enclosed: $ 325.00 . The application fee of $65.00 per acre (rounded up to the next acre) is assessed without a ceiling amount (Example: a 9-acre application fee.is $585). 7. Has an erosion and sediment control plan been filed? Yes No X Enclosed X 8. Person to contact should erosion and sediment control issues arise during land -disturbing activity: Name Jason L. Elliott El E-mail Address Jlelliottglpaproup com Telephone _(919) 954=1244 Cell # Fax # _(919) 954-1345 9. Landowner(s) of Record (attach accompanied page to list additional owners): Craven County Regional Airport Authority 1252) 638-8591 (919) 638-5930 Name Telephone Fax Number Post Office Box 3258 200 Terminal Drive Current Mailing Address Current Street Address New Bern NC 28564 New Bern NC City State Zip City State Zip 26562 10. Deed Book No, 1129 Page No. 0006 Provide a copy of the most current deed. Part B. Person(s) or firm(s) who are financially responsible for the land -disturbing activity (Provide a comprehensive list of all responsible parties on an attached sheet): Craven County Regional Airport Authority Name Post Office Box 3258 Current Mailing Address New Bern NC 28564 City State Zlp Telephone (252) 638-8591 E I ^ddr25^ urrent Street Address City Fax Number (252) 638-5930 2. (a) If the Financially Responsible Party is not'a resident of North Carolina, give name and street address of the designated North Carolina Agent: Name E-mail Address Current M9ilinn Arlrlrpsc c'...,.r Aaa.,,.... City State Zip City State Zip Telephone Fax Number (b) If the Financially Responsible Party is a Partnership or other person engaging in business under an assumed name, attach a copy of the Certificate of Assumed Name. If the Financially Responsible Party is a Corporation, give name and street address of the Registered Agent: Name of Registered Agent Current Mailing Address City State E-mail Address Current Street Address City Telephone Fax Number State Zip The above information is true and correct to the best of my knowledge and belief and was provided by me under oath (This form must be signed by the Financially Responsible Person if an individual or his attorney -in -fact, or if not an individual, by an officer, director, partner, or registered agent with the authority to execute instruments for the Financially Responsible Person). I agree to provide corrected information should there be any change in the information provided herein. Tom Braaten Type or prin me Signature Airport Director Title or Authority Date 1, _ Kathl pan T Si m¢hi na , a Notary Public of the County of Cra,,Qn State of North Carolina, hereby certify that Tom Braaten appeared personally before me this day and being duly sworn acknowledged that the above form was executed by him. Witness my hand and nntarial ggal this 't, rl rinv of o 9n no itoAL Seal 7Notary My commission expires pecembpr 4, ?01n All components of the wet detention basin system shall be maintained in good working order I acknowledge and agree by my signature below that I am responsible for the performance of the seven 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. Print name: JOHti 4, P2/Cc, J2 Title: /? IAPO/CT p//Z6-G72b/2- Address: /501 412Po27— 2oR0, NEw B�2v, NG2S5�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. 1 Shirley F. Weigl , a Notary Public forthe State of North Carolina Countyof Craven , do hereby certify that J n h n H. P r i c a, jr personally appeared before me this 3 0 t h day of July , 1999 , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, My commission SEAL February 28, 2003 Form SWU-102 Rev 3.99 Page 4 of 4 Maintenance activities shall be performed as follows: After every significant runoff producing rainfall event and at least monthly: a. Inspect the wet detention basin system for sediment accumulation, erosion, trash accumulation, vegetated cover, and general condition. b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within 2 to 5 days as designed. 2. Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative cover to maintain a maximum height of six inches, and remove trash as needed. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to maintain proper functioning. 4. Remove accumulated sediment from the wet detention basin system semi-annually or when depth is reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality (i.e. stockpiling near a wet detention basin or stream, etc.). The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the permanent pool depth reads 7. 0 feet in the main pond, the sediment shall be removed. When the permanent pool depth reads -7-0 feet in the forebay, the sediment shall be removed. BASIN DIAGRAM (fill in the blanks) Permanent Pool Elevation o. o Sediment Re L.ation � 75 ------- -- Sediment Removal Elevation 7 D 75% Bottom ElL- o %--------------------------------------------- 1-25% Bottom Elevation L. a FOREBAY MAIN POND 5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These plants shall be encouraged to grow along the vegetated shelf and forebay berm. 6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain shall be minimized to the maximum extent practical. Form SWU-102 Rev 3.99 Page 3 of 4 THE LPA GROUP of North Carolina, p.o. Transportation Consultants 4904 Professional Court, Suite 201 Post Office Box 17736 Raleigh, North Carolina 27619 (919) 954-1244 FAX (919) 954-1345 September 17, 1999 Mr.Bill Moore NCDENR Division of Water Quality 943 Washington Square Mall Washington, NC 27889 Re: Craven County Regional Airport Terminal Parking Expansion Dear Bill: SEP 2 0 1999 - WASHINGTON REGIONAL OFFICE Dyo Please find enclosed two sets of revised plans for the stormwater management area for the above referenced project. As requested, we have made the following changes to the plans: • Modified the side slopes to 6:1 • Realigned the outfall pipe to flow into the forebay Thank you for your cooperation and if you have any questions or need additional information please feel free to call. Sincerely, THE LPA GROUP of North Carolina, p.a. ,eJ M. Irby, P.E. ect Engineer Enclosures Member of THE LPA GROUP INCORPORATED ATLANTA, GA • CHARLESTON, SC • CHARLOTFE,NC • CHICAGO, IL • COLUMBIA, SC • GREENSBORO, NC • KNOXVILLE, TN • MOBILE, AL MYRTLE BEACH, 5C 0 PHILADELPHIA, PA 0 RALEIGH, NC 0 RICHMOND,VA 0 TALLAHAS5E, FL 0 TAMPA, FL State of North Carolina Department of Environment and Natural Resources Division of Water Quality o®®® James B. Hunt, Governor DENR Bill Holman, Secretary ary ®® �� Kerr T. Stevens, Director NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES �t DIVISION OF WATER QUALITY September 30, 1999 Craven Regional Airport Authority Attn: Mr. John H. Price, Jr. w, 1501 Airport Road SwT�B66 New Bern, NC 28560 �eP/moo Subject: Stormwater Permit No. SW7990825 Craven Airport Parking Expansion High Density Stormwater Project Craven County Dear Mr. Price: - The Washington Regional Office received the completed Stormwater Application for the subject project on September 20, 1999. 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. SW.7990825 dated September 30, 1999, to Craven County Regional Airport Authority. This permit shall be effective from the date of issuance until September 30, 2009 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. 943 Washington Square Melt. Washinipnn. Nosh Carolina 27989 Telephone 252.946-6451 FAX 252-946.9215 Craven Regional Airport Authority September 30, 1999 Page Two If you have any questions, or need additional information concerning this matter, please contact Bill Moore at (252) 946- 6981, extension 264. rs Sincerely, �� -Jim Mulligan Water Quality Regional Supervisor Washington Regional Office 0 c�': The LPA Group of North Carolina Craven County Inspections ywashington Regional Office Central Files State Stormwater Management Systems Permit No. SW7990825 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 Craven County Regional Airport Authority Craven County FOR THE construction, operation and maintenance of stormwater management systems 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 w, data as attached and on file with and approved by the Division of Water Quality and considered a part of this permit for a wet detention pond,to serve the new Terminal Parking Expansion located near New Bern, ,NC. This permit shall be effective from the date of issuance until September 30, 2009 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 stc'rmwater system has been approved for the management of d± stormwate�r runoff as described on page 4 of this permit, the Project Data Sheet. 3. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the r permit. 3 M I DIVISION OF WATER QUALITY PROJECT DATA Project Name: Craven Airport Parking Expansion Permit Number: SW7990825 Location: Craven County Applicant: Craven Regional Airport Mailing Address: 1501 Airport Road New Bern, NC 28560 Application Date: 8/2/99; original 9/20/99; complete Water Body Receiving Stormwater Runoff: Scotts Creek Classification of Water Body: SC Total Site Area: 10.1 acres Total Impervious 2.3 acres Surfaces Allowed: Pond/Basin Depth: 4.0 ft Required Surface Area 8359 sq ft (SA/DA): Provided Surface Area: 8405 sq ft Required Storage Volume: 36,663 cu ft Provided Storage Volume: 37,462 cu ft Controlling Orifice: 3.0-inch dia. 0 4. No homeowner/lot owner/developer shall be allowed to fill in, alter, or pipe any vegetative practices (such as swales) shown on the approved plans as part of the stormwater management system without submitting a revision to the permit and receiving approval from the Division. 5. 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. :4 In addition, the Director may determine that other revisions to the project should require a modification to the permit. 6. 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 permittee will comply with the following schedule for construction and maintenance of the stormwater management system. a. 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 surfaces except roads. b. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately. 2. The facilities must be properly maintained and operated at all times. The approved Operation and Maintenance Plan must be followed in its entirety and maintenance must occur at the scheduled intervals. 3. The permittee shall at all times provide the operation and maintenance necessary to assure the permitted stormwater system functions at optimum efficiency including, but not limited to: 5 s a. Semi-annual 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. 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. 5. 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 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. Mail the Certification to the Washington Regional Office, 943 Washington Square Mall, Washington, North Carolina, 27889, attention Division of Water Quality. 7. A copy_, of the approved plans and specifications shall be maintained on file by the Permittee for a minimum of five years from the date of the completion of construction. 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 143-215.6(a) to 143-215.6(c). 6 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. 9. 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. d? 5. 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. t_ Permit issued this the 30 th day of September,1999. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION tserr T. Stevens, Director Division of Water Quality By Authority of the Environmental Management Commission Permit Number SW7990825 . 7 Craven County Regional Airport Parking Expansion Wet Pond System New Bern, NC Stormwater Permit No. SW7990825 Designer's Certification `.9 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. Signature Registration Number y. Date M b