Loading...
HomeMy WebLinkAboutSW8960912_Historical File_20061114Michael F. Easley, Governor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources Alan W. Klimek, P.E. Director Division of Water Quality November 14, 2006 Ralph H. Griffin, Jr., President American Auto & Finance Company, Inc. Post Office Box 205 Wrightsville Beach, NC 28480 Subject: Stormwater Permit No. SW8 960912MOD American Auto & Finance High Density Project New Hanover County Dear Mr. Griffin: The Wilmington Regional Office received a complete, modified Stormwater Management Permit Application for American Auto & Finance on November 7, 2006. 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 960912MOD dated November 14, 2006, for the construction of the subject project. This permit shall be effective from the date of issuance until November 14, 2016, 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 sixty (60) 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 Chris Baker, or me at (910) 796-7215. Since I Edward Beck Regional Supervisor Surface Water Protection Section ENB/csb: S:IWQSISTORMWATERIPERMIT1960912MOD.nov06 cc: Mark Hargrove, P.E., Withers and Ravenel New Hanover County Building Inspections City of Wilmington Development Services Beth Wetherill, New Hanover County Engineering Chris Baker Wilmington Regional Office Central Files NowortCarolina tura!!r� North Carolina Division of Water Quality 127 Cardinal Drive Extension Wilmington, NC 28405 Phone (910) 796-7215 Customer Service Wilmington Regional Office Internet: www.ncwatemualitv.ore Fax (910) 350-2004 1-877-623-6748 An Equal Opportunity/Affirmative Action Employer— 50% Recycled/10% Post Consumer Paper State Stormwater Management Systems Permit No. SW8 960912MOD 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 Ralph H. Griffin, Jr., American Auto & Finance Company, Inc. American Auto & Finance 6401 Carolina Beach Road, Wilmington, New Hanover County FOR THE construction, operation and maintenance of a wet detention pond in compliance with the provisions of 15A NCAC 2H .1000 (hereafter referred to as the "stormwater rules'l 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 November 14, 2016, 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 32,915 square feet of impervious area. 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 960912MOD A The following design criteria have been provided in the wet detention pond and must be maintained at design condition: a. Drainage Area, 9cres: Onsite, ft : Offsite, ft2: Total Impervious Surfaces, ft2: Design Storm, inches: Pond Depth, feet: TSS removal efficiency: Permanent Pool Elevation, FMSI : Permanent Pool Surface Are ft Permitted Storage Volume, ft : Temporary Storage Elevation, FMSL: Controlling Orifice: Permitted Forebay Volume, ft3: Maximum Fountain Horsepower: Receiving Stream/River Basin: Stream Index Number: Classification of Water Body: II. SCHEDULE OF COMPLIANCE 1.21 52,653 N/A 32,915 1.5 4 90% 36 4,429 8,043 37.3 1"0 pipe 2,081 1/8 UT Intracoastal Waterway/ CPF 18-87-(25.5) SA OR (>1/2 mile from) 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. 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. Page 3 of 7 State Stormwater Management Systems Permit No. SW8 960912MOD 6. Decorative spray fountains will be allowed in the stormwater treatment system, subject to the following criteria: a. The fountain must draw its water from less than 2' below the permanent pool surface. b. Separated units, where the nozzle, pump and intake are connected by tubing, may be used only if they draw water from the surface in the deepest part of the pond. c. The falling water from the fountain must be centered in the pond, away from the shoreline. d. The maximum horsepower for a fountain in this pond is 1/8 horsepower. 7. Upon completion of construction, prior to issuance of a Certificate of Occupancy, and prior to operation of this permitted facility, a certification must be received from an appropriate designer for the system installed certifying that the permitted facility has been installed in accordance with this permit, the approved plans and specifications, and other supporting documentation. Any deviations from the approved plans and specifications must be noted on the Certification. A modification may be required for those deviations. 8. 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. 9. Access to the stormwater facilities shall be maintained via appropriate easements at all times. 10. 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 Mayor hermit was sought. f. Filling in, altering, or piping of any vegetative conveyance shown on the approved plan. 11. The permittee shall submit final site layout and grading plans for any permitted future areas shown on the approved plans, prior to construction. 12. 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. 13. 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. Page 4 of 7 State Stormwater Management Systems Permit No. SW8 960912MOD III. GENERAL CONDITIONS 1. 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 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 in writing of any name, ownership or mailing address changes within 30 days. Permit issued this the 14th day of November 2006. NORT ROLINA ENVIRONMENTAL MANAGEMENT COMMISSION 61 for Alan W. Klimbk, P.E., Director Division of Water Quality By Authority of the Environmental Management Commission Page 5 of 7 OFFICE USE ONLY Date Received Fee Paid Permit Number 2 S 1 State of North Carolina Department of Environmental and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM This form may be photocopied for use as an original L GENERAL INFORMATION 1. Applicants name (specify the name of the corporation, individual, etc. who owns the project): American Auto & Finance Company, Inc. 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Ralph H.Griffin, Jr., President 3. Mailing Address for person listed in Item 2 above: Post Office Box 205 City: Wrightsville Beach State: Telephone Number: (910) 392-4343 Zip: 28480 4. Project Name (subdivision, facility, or establishment name — should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): American Auto & Finance 5. Location of Project (street address): 6401 Carolina Beach Rd. City: Wilmington County: New Hanover 6. Directions to project (from nearest major intersection): On the southeast corner of the Carolina Beach and Golden Road intersection 7. Latitude: 34' 06' 54" N Longitude: 770 54' 00" W of project. 8. Contact person who can answer questions about the project:: Name: Mark Hargrove Telephone Number: ( 910) 256-9277 H. PERMIT INFORMATION: 1. Specify whether project is (check one): New Renewal X Modification 2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the existing permit number SW8 960912 and its issue date (if known) November 25,1996 Form SW-101 Version 3.99 Page 1 of 4 3. Specify the type of project (check one): Low Density X 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 1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative (one to two pages) describing stormwater management for the project. Stormwater will be treated by the use of a wet pond designed to remove 90% TSS. 2. Stormwater runoff from this project drains to the Cape Fear 3. Total Project Area: 1.43 acres. 4. Project Built Upon Area: 62.5 %. 5. How many drainage areas does the project have? 1 River Basin. 6. Complete the following information for each drainage area. If there are more than two drainage areas in the project, attach and additional sheet with the information for each area provided in the same format as below. Basin Information Drainage Area 1 Receiving Stream Name Unnamed Trib to Intracoastal Waterway Receiving Stream Class SA 01?W Drainage Area 52,653 SF — 1.21 AC Existing Im ervious*Area 26,426 SF — 0.61 AC Proposed Impervious* Area 6,489 SF — 0.15 AC % Impervious* Area (Total) 62.5% Impervious* Surface Area Drainage Area 1 On -Site Buildings 7,070 SF On -Site Streets - 0 - On -Site Parkin Pavement 25,845 SF On -Site Sidewalks (Concrete) - 0 - Other On -Site (future) - 0 - Off -Site - 0 - Total: 32,915 SF — 0.76 ac *Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas, sidewalks, gravel areas, etc. 7. How was the off -site impervious area listed above derived? N/A Form SWU-101 Version 3.99 Page 2 of 4 IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS The following italicized deed restrictions and protective covenants are required to be recorded for all subdivisions, out parcels, 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 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 the 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 (919) 733-5083 for the status and availability of these forms. Form SW-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 SW-106 Off -Site System Supplement Form SWU-107 Underground Infiltration Trench Supplement Form SWU-108 Neuse River Basin Supplement Form SW-109 Innovative Best Management Practice Supplement Form SWU-101 Version 3.99 Page 3 of 4 r 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: Ralph H. Griffin, Jr. Title: President, American Auto & Finance Co., Inc. Address: Post Office Box 205, Wrightsville Beach, NC 28480 Phone: (910) 392-4343 Date: Signature Note: The legally responsible party should not be a homeowners association unless more than 50%'of the lots have been sold and a resident of the subdivision has been named the president. I, eoej a Notary Public for the State of K) D(J1 &-no <<r u2- , County of �P +t�el�oJe� do hereby certify that ph f •1-gri personally appeared before me this �24 day of 1A and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, REBECCA A. GREEN NOTARY PUBLIC NEW HANOVER COUNTY, N.C. '►...s My Commission Expires 3-3-2009 My commission expires N! arch 3� o Form SWU-102 Rev 3.99 Page 4 of 4 WITHERS & RAVENEL ENGINEERS I PLANNERS I SURVEYORS 7040 Wrightsville Avenue, Suite ioi WILMINGTON, NORTH CAROLINA, 28403 (910) 256-9277 FAX (910) 256-2584 To: Cameron Weaver NC Division of Water Quality 127 Cardinal Drive Ext. Wilmington, NC 284o5 WE ARE SENDING YOU ❑ Shop Drawings ❑ Copy of Letter LETON DATE 11/o6/06 JOB NO. o610 1.00 I ATTENTION Cameron Weaver PHONE# RE. American Auto & Finance w 2 0 ❑ Attached ❑ Under separate cover via ❑ Prints ® Plans ❑ Samples ❑ Change order ❑ Diskette ❑ the following items: ❑ Specifications COPIES DATE NO. DESCRIPTION 2 Sets of Plans for Review 2 Stormwater Calculations 1 Articles of Organization 1 Check for $ ,000 for Express Application Fee 2 Or final and copy of Permit Application 2 Wet Detention Basin Supplement Permit Application THESE ARE TRANSMITTED as checked below: Z For approval ❑ Approved as submitted ❑ For your use ❑ Approved as noted ❑ As requested ❑ Returned for corrections ❑ For review and comment ❑ ❑ FOR BIDS DUE 20 ❑ PRINTS RETURNED AFTER LOAN TO US ❑ Resubmit ❑ Submit ❑ Return _ copies for approval copies for distribution corrected prints REMARKS: This package is submitted for the NCDWQ Express Stormwater Permit ffenclosures are notes noted, kindfynotffy us atone AMERICAN AUTO• & FINANCE NCDWQ STORM WATER CALCULATIONS November 6, 2006 ' .CEIVED NOV 0 8 2006 SEAL 19742 �GINEEP O DER MIN 101. 14�° Withers & Ravenel, Inc. 7040 Wrightsville Avenue, Suite 101 Wilmington, North Carolina 28403 (910) 256-9277 STORMWATER NARRATIVE AMERICAN AUTO & FINANCE NEW RANOVER COUNTY, NC SITE DESCRIPTION This +/- 1.43 acre site is located on Carolina Beach Road (S.R. 421) in New Hanover County, North Carolina. The site has previously been developed by American Auto & Finance as a high density project in 1996 and permitted by NCDWQ (Permit No. SW8 960912). The project will consist of the construction of an additional commercial building and related site improvements. The previous permit allocated future impervious area and the previous pond was sized to accommodate future impervious area for the State's regulations. The initial pond was allowed to be constructed due the site being farther than '/z mile from SA waters. A chlorides test was performed back in 1996 that allowed the project to be permitted with a wet pond. However, New Hanover County has developed stormwater regulations and the pond must be made larger in order to meet the County's requirements. The proposed disturbed area for this project is 0.70 acres and the total amount of impervious area draining to the stormwater management pond is 62.5%. The erosion control plan identifies the appropriate measures to be implemented for erosion control purposes during construction of the infrastructure associated with this development. SOILS The soils for the American Auto & Finance project consist of Leon (Hydrologic Soil Group B/D) and Kureb (Hydrologic Soil Group A). STORM DRAINAGE DESIGN The primary stormwater measure for this project is an expansion of an existing pond located in the northeast corner of the site. The stormwater will be conveyed via a piped system to the proposed pond by a drop inlet within the parking area and by sheet flow off the parking to a grassed swale that conveys the runoff to the forebay. The proposed wet detention pond is designed to control the post development peak discharge of the 2-yr, 10-yr, and 25-yr storm events so as not to exceed the pre -development peak runoff discharge rate for the same storms to meet New Hanover County's Stormwater Regulations. WITHERS & RAVENEL ENGINEERS I PLANNERS I SURVEYORS American Auto and Finance — Pond No. Ti Total Area Draining to Pond= 52,653 SF = 1.21 AC Total Proposed Impervious Surface Area Draining to Pond: Buildings Parking Lot = 7,070 sf = 25,845 sf 32,915 sf % Impervious draining to pond = 32,915 /52,653 = 62.5% Required Storage for 1.5-Inch of Runoff For Pond: (use Schueler Method) = 0.05 + 0.009 (1) = 0.05 + 0.009(62.5) = 0.613 = (1.5")(0.613)(1/12)(521653) = 4,032 cf (6,472 cf provided) POND DEPTH SA/DA % (FT) 4.0 5.32 If Pond Depth = 4.0 ft, minimum surface area = 2,927 sf Used 90% TSS chart to size pond Area @ elevation 36.0 = 4,429 SF > 2,927 sf POND SURFACE AREA (MIN.) (SF) 2,927 Required storage for forebay: 20% of total permanent pool volume = (0.2)(8,043 cf) = 1,609 cf (2,081 CF PROVIDED --- 25.9%) 1040 Wrightville Ave. Wilmington, North Carolina 28403 tel: 910-256-9277 fax:910-256-2584 www.withersravenel.com W1`I"HIIIRS `' RA►'VEMEL ENGINEERS I PLANNERS 1 SURVEYORS Pond Volume Contour Incremental Cumulative Elevation Area Volume Volume (ft) (s (cf) (cf) Bottom Elevation 32.00 604 0 0 33.00 940 772 772 34.00 1,349 1,145 1,917 35.00 1,912 1,631 3,547 Permanent Pool 36.00 2,919 2,416 5,963 Forebay Volume Contour Incremental Cumulative Elevation Area Volume Volume (ft) (� sq (2D (cf) Bottom Elevation 33.00 183 0 0 34.00 443 313 313 35.00 791 617 930 Permanent Pool 36.00 1,510 1,151 2,081 Combined Pond and Forebay Volume = 8,043 Forebay Volume is 253°/0. of Pond Volume 1040 Wrightville Ave. Wilmington, North Carolina 28403 tel: 910-256-9277 fax:910-256-2584 www.withersravenel.com WITHERS ENGINEERS I PLANNERS 1 SURVEYORS 1.5" STORAGE VOLUME Contour Incremental Cumulative Elevation Area Volume Volume (ft) (sf) (cf) (cf) Normal Pool 36.00 4,429 0 0 37.00 5,272 4,851 4,851 1" Storage Level 37.30 5,535 1,621 6,472 POND RELEASE TIME FOR CONTROL PIPE: POND ELEV. EFF. STORAGE VOL. RELEASED OUTFLOW RATE RELEASE TIME F CF CF CFS (HOURS) 37.30 6,472 1,621 0.030 15.0 37.00 4,851 4,851 0.026 51.3 36.00 0 TOTAL HOURS 66.3 DAYS 2.8 CONTROL PIPE: 1 INCH ORIFICE HOLE USED ORIFICE EQUATION TO DETERMINE OUTFLOW RATE Q = Cd*A* 2 h "1/2 IOyo Wrightville Ave. Wilmington, North Carolina 28403 tel: 910-256-9277 fax:910-256-2584 www.withersravenet.com WK DICKSON February 19, 1998 Ms. Linda Lewis Engineers N.C. Department of Environment, Planners Health, and Natural Resources Surveyors Water Quality Section 127 Cardinal Drive Extension Wilmington, NC 28405 Re: Stormwater Certifications for SW8 960912 American Auto and Finance Project New Hanover County Project No. 9622 Dear Ms. Lewis: MAR ®2 M8 Enclosed please find one (1) copy of the Engineer's Certification for the referenced project. Very truly yours, WK DICKSON Mark N. Hargrove, P.E. Encl.: As noted above. cc: Ralph H. Griffin, Jr. 3177 Wrightsville Avenue Other Offices: Atlanta, GA Hickory, NC Wilmington, North Carolina 28403 Asheville, NC Raleigh, NC 910 762-4200 Charlotte, NC Columbia, SC Fax 910 762-4201 www.wkdickson.com