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HomeMy WebLinkAboutSW8050807_CURRENT PERMIT_20060809STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW pS�g/&7 DOC TYPE � CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE �LY�or7F(Ilg YYYYMMDD o�w A r&9Qr, 0 Y August 9, 2006 Mr. W. Christopher Stephens, President Southwood Developers, Inc. 5022 Wrightsville Avenue Wilmington, NC 28403 Subject: Stormwater Permit No. SW8 050807 Bridgeport Townhomes High Density Project Brunswick County Dear Mr. Stephens: Michael F. Easley, Governor William G. Ras Jr., Secretary North Carolina Department of Environment and Natural Resources Alan W. Klimek, P.E. Director Division of Water Quality The Wilmington Regional Office received a complete Stormwater Management Permit Application for Bridgeport Townhomes on August 9, 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 050807 dated August 9, 2006, for the construction of the subject project. This permit shall be effective from the date of issuance until August 9, 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 Linda Lewis, or me at (910) 796-7215. Sincer 1 r', Edward Beck Regional Supervisor Surface Water Protection Section ENB/arl: S:1WQSISTORMWATIPERMIT1050807.aug06 cc: Comer Lyons, .P.E., Cape Fear Engineering Delaney Aycock, Brunswick County Building Inspections Linda Lewis Wilmington Regional Office Central Files Alotl � o Carolina Nahrra!!y North Carolina Division of Water Quality 127 Cardinal Drive Extension Wilmington, NC 28405 Phone (910) 796-7215 Customer Service Wilmington Regional Office Internet: www.ncwaterguality.ora Fax (910)350-2004 1-877-623-6748 An Equal Opportunity/Affirmative Action Employer -- 50% Recyded110% Post Consumer Paper State Stormwater Management Systems Permit No. SW8 050807 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 Christopher Stephens & Southwood Developers, Inc. Bridgeport Townhomes Trade Street & Amber Pines, Leland, Brunswick County FOR THE construction, operation and maintenance of a wet detention pond and for the treatment of a portion of the runoff in an offsite wet detention pond permitted under SW8 041041, 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 August 9, 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. The stormwater systems have been approved for the management of stormwater runoff as described in Sections 1.7 and 1.8 on page 3 of this permit. The stormwater controls labeled "Onsite Pond" anal "Offsite Pond" have been designed to handle the runoff from 104,446 ft and 152,333 ftz, respectively, of impervious area from this project. 3. The overall tract and each drainage area will be limited to the amount of built - upon area indicated on page 3 of this permit, and per the 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 areas of this project must be directed into the appropriate permitted stormwater control system. Page 2 of 8 State Stormwater Management Systems Permit No. SW8 050807 6. Pond No. 3 of Stormwater Permit Number SW8 041041 is designed to receive the runoff from 152,333 ft2 of impervious area generated by this project. As of the date of this permit, Pond #3 is permitted to and maintained by Southwood Developers, Inc. 7. The following design criteria have been provided in the °Onsite" wet detention pond and must be maintained at design condition: a. Drainage Area, acres: 4.5 Onsite, ft : 196,020 offsite, ft2: 0 b. Total Impervious Surfaces, ft2: 104,446 C. Design Storm, inches: 1 d. Pond Depth, feet: 1.0 e. TSS removal efficiency: 90% f. Permanent Pool Elevation, FMSI2: 68.0 9. Permanent Pool Surface Areq, ft : 11,840 h. Permitted Storage Volume, ft : 8,824 i. Temporary Storage Elevation, FMSL: 68.7 j. Controlling Orifice: 2 "0 pipe k. Permitted Forebay Volume, W: 2,416 I. Receiving Stream/River Basin: Banton Branch I Cape Fear M. Stream Index Number: 18-77-1-1-2 n. Classification of Water Body: "C Sw" 8. The following design criteria have been provided in the "Offsite" wet detention pond No. 3 permitted under SW8 041041 and must be maintained at design condition: a. Drainage Area, Acres: 17.71 Onsite, ft : 512,701 Offsite, ft2: 257,440 b. Total Impervious Surfaces, ft2: 332,671 Lot BUA, ft: 126,324 Roads/Parking, ft: 54,014 Offsite, ft (SW8 050807): 152,333 C. Design Storm, inches: 1 d. Pond Depth, feet: 7.0 e. TSS removal efficiency: 90% f. Permanent Pool Elevation, FMS�: 62.0 g. Permanent Pool Surface Ares, ft : 14,444 h. Permitted Storage Volume, ft : 28,906 i. Temporary Storage Elevation, FMSL: 63.8 j. Controlling Orifice: 2 "0 pipe k. Permitted Forebay Volume, ft3: 9,240 I. Receiving Stream/River Basin: Banton Branch 1 Cape Fear M. Stream Index Number: 18-77-1-1-2 n. Classification of Water Body: "C Sw" 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. Page 3of8 State Stormwater Management Systems Permit No. SW8 050807 3. 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. 4. 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. 5. 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. 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. The facilities shall be constructed as shown on the approved plans. This permit shall become void unless the facilities are constructed in accordance with the conditions of this permit, the approved plans and specifications, and other supporting data. 8. 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. 9. Access to the stormwater facilities shall be maintained via appropriate easements at all times. 10. 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. Page 4 of 8 State Stormwater Management Systems Permit No. SW8 050807 11. 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. 12. 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. 13. The permittee shall submit final site layout and grading plans for any permitted future areas shown on the approved plans, prior to construction.. . 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 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. Page 5 of 8 State Stormwater Management Systems Permit No. SW8 050807 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 9th day of August 2006. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION for Alan vv. KnmeK, h'.t., ulrector Division of Water Quality By Authority of the Environmental Management Commission Page 6 of 8 State Stormwater Management Systems Permit No. SW8 050807 Bridgeport Townhomes Stormwater Permit No. SW8 050807 Brunswick 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 the construction was observed to be built within substantial compliance and intent of the approved plans and specifications. The checklist of items on page 2 of this form is included in the Certification. Noted deviations from approved plans and specification. Signature Registration Number Date SEAL Page 7 of 8 State Stormwater Management Systems Permit No. SW8 050807 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. Ail 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 Delaney Aycock, Brunswick County Building Inspections Page 8of8 OFFICE USE ONLY Daie Receiyqd Fee Paid Permit 05 0 State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM This form moY be photocopied for use as an original 1. GENERAL INFORMATION: 1. Applicant's name (specify the name of the corporation, individual, etc. who owns the project): Southwood Developers, Inc. 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): W. Christopher Stephens, President 3. Mailing Address for person listed in item 2 above: 5022 Wriahtsville Ave. City: Wilmington State: NC Zip: 28403 Telephone Number: 910.392.7201 4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Bridz;eport Townhomes 5. Location of Project (street address): North from intersection of Trade St. and Amber Pines Drive in Leland, NC, City: Town of Leland County. 6. Directions to project (from nearest major intersection): 284-feet north from intersection of Trade St. and Amber Pines Drive in Lei 7. Latitude: 34° 15.854' N Longitude: 78' 04.25' W 8. Contact person who can answer questions about the project: Name: Chris Stephens Telephone Number 11. PERMIT INFORMATION: Brunswick 1. Specify whether project is (check one): X New Renewal NC. of project 910.392.7201 Modification 2. If this application is beings submitted as the result of a renewal or modification to an existing permit, list the Form: SWU-101 Version 3.99 Page 1 of existing pennit number And its issue date (if known) 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. I11. PROJECT INFOR NATION 1. In the space provided below, summarize how stonmwater will be treated. Also attach a detailed narrative (one to two pages) describing stormwater management for the project. Curb and gutter collection/conveyance system with wet detention ponds for on -site treatment. ?. Stormwater runoff from this project drains to the Cape Fear River basin. 3. Total Project Area: 14.31 acres 4. Project Built Upon Area: 41.2 % 5. How many drainage basins does the project have? 2 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. Basin Information Draina e Area 1 Drainage Area 2 Receiving Stream Name BANTON BRANCH BANTON BRANCH Receiving Stream Class SC SC Draina Te Area I90OZO4+35-9-'� s . ft 33& acres 259283 s . ft. 595 acres Existing Impervious* Area 0 0 Proposed Impervious* Area 104446 s . ft. 2.40 acres 152333 s . ft. 3.49 acres % Impervious* Area total 72.7% 58.7% Impervious* Surface Area Drainage Area I Drainage Area 2 On -site Buildings 52698 s . ft. 1.21 acres 70107 s . ft. 1.61 acres On -site Streets 41802 s . ft. .96 acres 67281 s . ft. 1.54 acres On -site Parking 0 (included in street area) 0 (included in street area On -site Sidewalks 9946 s . ft. .23 acres 14945 s . ft. 34 acres Other on -site 0 0 Off site 0 0 Total: 104446 s . ft. 2.40 acres I Total: 152333 sq. ft. 3.49 acres * hnpervious area is defined cis the built upon area including, but not limited to, buildings, roads, parkin,= areas, sidewalks, gravel areas, etc. Form: SWU-101 Version 3.99 Page 2 of-4 7. How was the off -site impervious area listed above derived? N/A 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 u4th state stor•nmwter rnanagenrent permit number as issued by the Division of barter Quality. These covenants nrav not be changed or deleted n'ithout 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, gra+-el, concrete, brick, stone, slate or similar material but do not include hood decking or the li,ater• surface ofslvnrunrng pools. 3. Sw!ales shall not be filled in, piped, or altered except as necessary to provide clrivelvcry crossings. 4. Built -upon area in excess area of the permitted mnount requires a ,state stornniater management permil modifrc•alion prior to construction, 5. All permitted runoff front owparcels or f mire development shall be directed into the permitted stornll,ater control system. These connections to the stornnrater control system shall be performed in a manner that maintains the integrity and petformance of the system as per•nOted. 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 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 V1. 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. In' i • 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 S420 (payable to NCDENR) • Detailed narrative description of stormwater treatment /management • Two copies of plans and specifications, including: -Development/Project name -Engineer and firm -Legend -North Arrow -Scale -Revision number & 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) VI1. AGENT AUTHORIZATION If you wish to designate submittal authority to another individual or firm so that they may provide information on you behalf, please complete this section: Designated agent (individual or firm): Cape Fear Engineering Mailing Address: 151 Poole Road, Suite 100 City: Belville State: NC Phone: 910.383.1044 Fax. 910.383.1045 Vill. APPLICANT'S CERTIFICATION Zip: 28451 I, (print or type name of person listed in General Information,.item 2) W. Christopher Stephens certify that the information includ d on t is permit appli ation form is, to the best of my knowledge, correct and that the project will be construct in formance wit e approved plans, that the required deed restrictions and protective cov nts wil rec d, a a proposed project complies with the requireme s of 1 A NCAC 2H .1000. Signature: '� Date: � Form: SWU-101 Version 3.99 Page 4 ol'4 Permit No. �iN �Fa.i0�_ (to be provided big DWJ State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM VET DETENTION BASIN SUPPLEiMENT This form may be photocopied for use as an original DWQ 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. 1. PROJECT INFORMATION Project Name: Bridgeport Townhomes Contact Person: Chris 5tephen5 Phone Number: (9 10) 392-720 1 For project with multiple basins, specify which basin this worksheet applies to: On -bite Pond Elevations Basin Bottom Elevation G 1 ft. (floor of the basin) Permanent Pool Elevation G8 ft. (elevation of the orifice) Temporary Pool Elevation G8.7 ft. (elevation of the discharge structure overflow') areas Permanent Pool Surface Area 1 1 640 sq. ft. (water surface area at the orifice elevation) Drainage Area 4.5 ac. (on -site and off -site drainage to the basin) Impervious Area 2.40 ac. (on -site and off -site drainage to the basin) volumes Permanent Pool Volume 33 ! GG cu. ft. (combined volume of main basin and forebay) Temporary Pool Volume 8824 cu. ft. (volume detained above the permanent pool) Forebay Volume GG64 cu. ft. (approximately 20% of total volume) Other parameters SA/DA1 2.05% (surface area to drainage area ratio from DyVQ table) Diameter of Orifice 1 .5 in. (2 to 5 day temporary pool draw -down required) Design Rainfall I in. Design TSS Removal 2 90 % (minimum 85% required) rec . 5-1(0 2C0& Form: SWU-102 Rev 3.99 Page 1 of 4 Footnotes: ' When using the Division SA/DA tables, the correct SA/DA ratio for permanent pool sizing actual imperviousshould be computed based upon the % and permanent pool depth. Linear interpolation should be employed to determine the correct value !or non- standard table entries. 2 In the 20 coastal counties, 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 Eor both 85% TSS removal and 90% TSS removal. I1. 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 2Ft. 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: 0/0_� a. b. c. d. e. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet). The forebay volume is approximately equal to 20% of the basin volume. The temporary pool controls runoff from the design storm event. The temporary pool draws down in 2 to 5 days. 11'required, a 30-116ot vegetative filter is provided at the outlet ( include non -erosive flow calculations) The basin length to width ratio is greater than 3:1. g. The basin side slopes above the permanent pool are no steeper than 3:1. h. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail). E Vegetative cover above the permanent pool elevation is specified. A trash rack or similar device is provided for both the overflow and orifice. A recorded drainage easement is provided for each basin including access to nearest right - of —way. 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. m. A mechanism is specified which will drain the basin for maintenance or an emergency. .,k<, ?a WC A-:3LK G ENE.' —,A7 oV_ I11. 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 do3no incorporate a vegetated filter at the outlet. This system (check one) 0 does doincorporate pretreatment other than a forebay. Maintenance activities shall be performed as follows: Form: SNVU-102 Rev 3.99 Page 2 of 4 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. 3. 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 detennine the sediment elevation shall be as such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the permanent pool depth reads 5.25 feet in the main pond, the sediment shall be removed. When the permanent pool depth reads 3.00 feet in the forebay, the sediment shall be removed. BASIN DIAGRAM (frll in the blanks) NZ7 Permanent Poo! Elevation = 68.0 Sediment Removal Ele tion-_ 65.0 7.5%n{ / \ Sediment Removal Elevation = 62.75--- 7.5% Bottom Elevation — 64.0 \ 25%♦ / ` 5ottom Elevation = 61 .O 25% 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. 7. All components of the wet detention basin system shall be maintained in good working order. Form: SWU-102 Rev 3.99 Page 3 of 4 I'acknowl edge 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: W. Christopher 5tephe-r5 Title: President Address: 5022 Wnc3ht5vlle Avenu Phone: (9 10) 392-7201 Signature: Date: A rS 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, /-/5(-o-7-/,,f ,a Notary Pubic for the State of. p,L arohno' County of ,do hereby certify that . CAOS-1-C personally appeared before me this Znd day of &VemkeX- ,and a nowledge the due execution of the foregoing wet detention basin maintenance requirements. Witness my hand and official seal, PIP Z' N0 rq A` p A USL1G V . d�•• SO 12/*�inrftl � SEAL My commission expires Marnt O�7 'g'w J Form: SNVU-102 Rev 3.99 Page 4 of 4 r. NN � • 1j+�•rss�►+r+wy P� s� jr�� ' , � t Permit No. (Io be provided by DPVC)) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM OFF -SITE SYSTEM SUPPLEMENT FOR DEVELOPMEN'r DRAINING TO PERM1771:1) OFF -SITE TREATMENT SYSTEMS This form may be photocopied for use as an original DWQ Stormwater Management flan Review: A complete stormwater management plan submittal includes a stormwater management permit application, an off -site system supplement for each off -site stormwater treatment system, appropriate supplement forms for any on -site stormwater treatment systems, and plans and specifications showing all stormwater conveyances and drainage details for the project. I. PROJECT INFORMATION Prolect Bridgeport Townhomcs Contact Chris Stephens Phone Number: (910) 3392-7201 Is all drainage from the project directed to the off -site system? (circle Yes No one): 11. OFF -SITE SYSTEM INFORMATION (please complete the following information for the off -site system that will treat runoff from your project): Permit No. SW8 041041 Project Name: Bridgeport Townhomes Type of System (wet pond, infiltration basin, etc.): Wet Pond, Pond III -- SWS O41041MOD Lot No. (if part of a subdivision): UI How much built upon area draining to the permitted treatment system has been allocated to this project? III. REQUIRED ITEMS CHECKLIST Prior to issuing an off -site permit, verification of the following information must be provided. Initial in the space provided to indicate that the following requirements have been met and supporting documentation is attached. If the applicant has designated an agent in the Stormwater Management Permit Application Form, the agent may initial below. If a requirement has not been met, attach justification. Form SWIJ-106 Ver 3.99 Palle I of 2 Applica s Initials MAKI a. Deed restrictions limiting the built -upon area on the site have been recorded. VLW I). Engineers certification for the existing off -site system has been submitted to DWQ. c. There are no outstanding Notices of Violation for the off -site system. d. Off -site system is in compliance with the issued permit. 1V. STORMWATER COLLECTION SYSTEM MAINTENANCE REQUIREMENTS Mowing will be accomplished as needed according to the season. Grass height will not exceed six inches at any time. 2. Accumulated sediment and trash will be removed from the collection as necessary. Swales and ditches will be reseeded or sodded following sediment removal. Eroded areas of swales and ditches will be repaired and reseeded. Swales and ditches will be revegetated as needed based on the monthly inspections. 4. The collection system, including catch basins, curbs cuts, velocity reduction devices, and piping, will be inspected monthly or after every significant runoff producing rainfall event. Trash and debris will be cleared away from grates, curb cuts, velocity reduction devices, and piping. 5. The collection system may not be altered in any way without prior approval from NCDENR Division of Water Quality. I acknowledge and agree by my signature below that I am responsible for maintaining the stormwater collection system in accordance with the above 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 and Title: W. Christopher Stephens President Address: 5022 Wrightsville Ave. Phone: Signature: (/U, (/ ' Note: The legally responsible p rty shoo 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. t, a Notary Public for the State of ar ,County of lyedo ereby certif thatW. /,� personally appeared before me this Z^� day of and acknowled e the due e, cation of the foregoing infiltration basin maintenance requirements. Witness my hand and official seal, OFFICIAL SEAL ¢ Notary Public . North Carolina 1 NEW HANOVER COUNTY a 's H. SCOTT KENNEDY, JR, My commision expires Q�IG,G a� 1aa t'orrn SWU-106 Ver 3.99 Pmze 2 of 2