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HomeMy WebLinkAboutSW6071002_CURRENT PERMIT_20080114STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. DOC TYPE CURRENT PERMIT APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATEZ� YYYYM M D D W ATFR Q I v r Elliott Brown Chairman of Expansion Committee 2164 Neill's Creek Road Lillington, North Carolina 27546 Michael F. Easley, Governor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources Coleen H. Sullins, Director Division of Water Quality January 14, 2008 DENR-FRO MAR U i 2008 DWQ Subject: Stormwater Permit No. SW6071002 Pleasant Union Christian Church Harnett County, North Carolina Dear Mr. Brown: L � The received a complete Stormwater Management Permit Application for the Pleasant Union Christian Church on January 10, 2008. Staff review of the plans and specifications has determined that the project, as proposed, will comply with the Stormwater Regulations set forth in Session Law 2006-246. We are forwarding Permit No. SW6071002 dated January 14, 2008, for the construction of the subject project. This permit shall be effective from the date of issuance until January 15, 2018, 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. This project will be kept on file at the Fayetteville Regional Office. If you have any questions, or need additional information concerning this matter, please contact at the Fayetteville Regional Office at Systel Building, 225 Green St., Suite 714, Fayetteville, North Carolina, 28301- 5094, telephone no. 910-433-3300. Sincerely, ,>� ?x2w for Coleen H. Sullins cc: Glenn Tew, Jordon — Tew & Associates, P.A. (Fayetteville Regional Office Stormwater Permitting Unit Central Files e-I 4 1 ��VONV � ,!;, I j State Stormwater Management Systems Permit No. SW SW6071002 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 PLEASANT UNION CHRISTIAN CHURCH HARNETT COUNTY, NORTH CAROLINA FOR THE construction, operation and maintenance of a wet detention pond in compliance with the provisions of Session Law 2006-246 (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 January 14, 2018, and shall be subject to the following specified conditions and limitations: I. DESIGN STANDARDS 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 93,608 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 1 of 4 State Stormwater Management Systems Permit No. SW SW6071002 6. The following design criteria have been provided in the wet detention pond. and must be maintained at design condition: a. Drainage Area, acres: 3.26 b. Total Impervious Surfaces, ft2: 93,608 C. Design Storm, inches: One inch d. TSS removal efficiency: 85% e. Permanent Pool Elevation, FMSL: 85.50 f. Permanent Pool Surface Area, fe: 14,411 g. Permanent Pool Volume, ft3: 43,640.91 h. Temporary Pool Volume, ft3: 7,616.23 i. Temporary Pool Elevation, FMSL: 86.03 j. Controlling Orifice: 1.5" 0 pipe k. Permitted Forebay Volume, ft3: 8,703.73 I. Receiving Stream/River Basin: UT to West Buies Creek /Cape Fear M. Classification of Water Body: WS-IV II. SCHEDULE OF COMPLIANCE 1. The stormwater management system shall be constructed in its entirety, vegetated and operational for its intended use prior to the construction of any built -upon surface. 2. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately. 3. The permittee shall at all times provide the operation and maintenance necessary to assure the permitted stormwater system functions at optimum efficiency. The approved Operation and Maintenance Plan must be followed in its entirety and maintenance must occur at the scheduled intervals including, but not limited to: a. Semiannual scheduled inspections (every 6 months). b. Sediment removal. c. Mowing and revegetation of slopes and the vegetated filter. d. Immediate repair of eroded areas. e. Maintenance of all slopes in accordance with approved plans and specifications. f. Debris removal and unclogging of outlet structure, orifice device, flow spreader, catch basins and piping. g. Access to the outlet structure must be available at all times. 4. Records of maintenance activities must be kept and made available upon request to authorized personnel of DWQ. The records will indicate the date, activity, name of person performing the work and what actions were taken. 5. Decorative spray fountains will be allowed in the stormwater treatment system, Page 2 of 4 State Stormwater Management Systems Permit No. SW SW6071002 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. 6. 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. 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 Major permit 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. Page 3 of 4 State Stormwater Management Systems Permit No. SW SW6071002 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. 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. 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 14th day of January, 2008. NORTH CAROLINA Q VIRONMENTAL MANAGEMENT COMMISSION for Division of Water Quality By Authority of the Environmental Management Commission Page 4 of 4 Stormwater Permit No. SW6071002 Pleasant Union Christian Church Harnett County, North Carolina 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 1 of 2 Stormwater Permit No. SW6071002 Pleasant Union Christian Church Harnett County, North Carolina Certification Requirements: 1. The drainage area to the system contains approximately the permitted acreage. 2. The drainage area to the system contains no more than the permitted amount of built -upon area. 3. All the built -upon area associated with the project is graded such that the runoff drains to the system. 4. All roof drains are located such that the runoff is directed into the system. 5. The outlet/bypass structure elevations are per the approved plan. 6. The outlet structure is located per the approved plans: 7. Trash rack is provided on the outlet/bypass structure. 8. All slopes are grassed with permanent vegetation. 9. Vegetated slopes are no steeper than 3:1. 10. The inlets are located per the approved plans and do not cause short- circuiting of the system. 11. The permitted amounts of surface area and/or volume have been provided. 12. Required drawdown devices are correctly sized per the approved plans. 13. All required design depths are provided. 14. All required parts of the system are provided, such as a vegetated shelf, and a forebay. 15. The required system dimensions are provided per the approved. plans. cc: NCDENR-DWQ Regional Office Page 2 of 2 to Jordan - Tew & Associates, p,t MI NEEM0 SVRIEYNC, MATERIALS PEsm(; & i0 MSIRued9hcat.(ZIP2a334) 4; " Pouf OQIc6 Box 249 Duna, North Carokm 2&333 Ronne & Jordan, P. L.S. Johnny0IMSTow, P.& OCT 2 3 2009 IM159 To: e wl`i` S K '1,11 _: Date: ��� n---�j Company: _�� G. Sian . diCr �fjLocation: �ir y���euNfi/ l%I % �iai� Service Gerrity Pf0*Name; Lr-(eaSa -•-_�-.—..-_-�_,�._S�.�i ,�. �c�i is c�%. �ecf __,(�✓1inN -L-N NiQ Yf'iaH G(tuyc�. 2'14677 — IN We Transmit: �Harewith In Accordance With your Request The Following: ❑ Drawings Praliminary ❑ Test Results Other For Your: ❑ Approval Use ❑ Review dr Comment rtly' ecord Number of Sets or Copies Date Description Remark9 `transmitted By: Copies To: E 2 6wy s Stormwater Permit No. SW6071002 Pleasant Union Christian Church Harnett County, North Carolina Designer's Certification I, u aN v rrk"ol Cw, as a duly registered tno i 4eer in the State of Nortfi Carolina, having been authorized to observe eriodicall / weekly/ full time) the construction of the project, TIe a5am+ 61VI ro VI (iN Nt ST Iaq GNVYL� (Project) for Iptee45il0f (/oioA arrsfigz.J 0roject 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 m e oiie alp Ved 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: SEAL Signature e,,..J Registration Number Z/4.5 E0 Date SEAL 14580 NIL rt*t r »• INt`0 r N 0�.•. �trnun,ua Page I of 2 Stormwater Permit No. SW6071002 Pleasant Union Christian Church Harnett County, North Carolina 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. 1�L4. All roof drains are located such that the runoff is directed into the system. -1-J' —r"� -The.outlet/bypass structure elevations are per the a 6• The outlet structur�re s 1 c (�.; per the approved PProved plan. plans: U 7• Trash rack is provided on the outlet/bypass structure. T $• All. slopes are grassed with permanent vegetation. g• 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. Al- 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 Page 2 of 2 OFFICE USE ONLY , ,', Date Received Fee Paid Permit Number f7 31 bi S OS ` SLo60 f Dom State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM This form may be photocopied for use as an original I. GENERAL INFORMATION 1. Applicants name (specify the name of the corporation, individual, etc. who owns the project): Pleasant Union Christian Church 2. Pririt Owner/Signing Official's name and title (person legally responsible for facility and compliance): Elliott Brown (Chairman of Expansion Committee) 3. Mailing Address for person listed in item 2 above: 2164 Neill's Creek Road r,, „; Lillington �. NC 27546 Telephone Number: ( 910 ) 893-4490 4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Pleasant Union Christian Church 5. Location of Project (street address) 2164 Neill's Creek Road City: Lillington, NC 27546 County: Harnett 6. Directions to project (from nearest major intersection): Take Hwy 421 North from Dunn toward Lillington. Turn right on SR 1513 (Neill's Creek Road). Project is at intersection of NCSR 1513 an(h NCSR 1514 (Mamie pc urch Road). 7. Latitude: 35.4389 ' Longitude: 78.7743 of project 8. Contact person who can answer questions about the project: Name: Glenn Tew Telephone Number: ( 910 ) 892-5159 II. PERMIT INFORMATION: 1. Specify whether project is (check one): x New 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 permit number N/A 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. 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. Storm water will be collected on site from all imuercions areas by q qPries of drop - inlets -and swales and be transported by swalesspd gravity storm pipes to a permanent on -site wet detention pond. 2. Stormwater runoff from this project drains to the Cape Fear River basin. 3. Total Project Area: 3.26 acres 4. Project Built Upon Area: 5•Q 5 % 5. How many drainage areas does the project have? 1 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. BasinInformatioR(total)l .�',-Draina&A,e l;,Drainage Area 2 , : ':`' ReceivingStreamto West Buies CreekReceiving StreamDrainage Area26 ac (142,0065 sf)Existing ImperviProposed ImpervImpervious* A.95 919 SurfacOn-site. BuildingsOn-site *WTotaLn ge'Area 1,_Drainage Area 2Impervious. Streets,377 sf)On-site Parking 787 sf)On-site Sidewalks Other on -site, 582 sf )Off -site Total: Impervious area is defined as the built upon area me u m , , K ra. �..,s 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? /6( 06 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 (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 VI. SUBMITTAL REQUIREMENTS Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ). A completepackage includes all of the items listed below. The complete application package should be submitted to the appropriate DWQ Regional Office. 1. Please indicate that you have provided the following required information by initialing in the space provided next to each item. /O !� Initials • Original and one copy of the Stormwater anagement Permit Application Form 6 _r • One copy of the applicable Supplement orm(s) for each BMP • Permit application processing fee of $ (payable to NCDENR) A . i • Detailed narrative description of stormwater treatment/management A , T, • Two copies of plans and specifications, including: A 'T• - 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) VII. AGENT AUTHORIZATION If you wish to designate authority to another individual or firm so that they may provide information on your behalf, please complete this section. Designated agent (individual or firm) Mailing Address: PO Box 249 City: Dunn VIII. APPLICANT'S CERTIFICATION Jordan—Tew & Associates, PA NC Lbj_i� Zip: Fax: ( 910 ) 892-1893 I, (print or type name of person listed in General Information, item 2) Eliott Brown (Chairman of Expansion certify that the information included on this permit application form is, to the best of my now e ge, 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. Signature: &,0�- Date: Form SWU-101 Version 3.99 Page 4 of 4 Permit No. (to be provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form may be photocopied for use as an original 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. I. PROJECT INFORMATION Project Name: . Pleasant Union Christian Church Contact Person: Glenn Tew Phone Number: (910 892-5159 For projects with multiple basins, specify which basin this worksheet applies to: elevations Basin Bottom Elevation Permanent Pool Elevation Temporary Pool Elevation 78.00 ft. 1 areas Permanent Pool. Surface Area 14 411 sq. ft. Drainage Area 3 - 26 ac. Impervious Area 2.15 ac. volumes Permanent Pool Volume Temporary Pool Volume Forebay Volume'. Other parameters SA/DA1 Diameter of Orifice Design Rainfall' Design TSS Removal 2 (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) 43,640.91 cu. ft. (combined volume of main basin and forebay) 7,616.23 cu. ft. (volume detained above the permanent pool) 8,703.73 cu. ft. (approximately 20% of total volume) 2.68 (surface area to drainage area ratio from DWQ table) 1.5 in. (2 to 5 clay temporary pool draw -down required) 1 in. 85 % (minimum 85% required) Form SWU-102 Rev 3.99 Page I of 4 t 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. 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 for both 85% TSS removal and 90% TSS removal. II. REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements per the Stormwater Best Management Practices Manual (N.C. Department of Environment, Health and Natural Resources, 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 a. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet). b. The forebay volume is approximately equal to 20% of the basin volume. I� .7 c. The temporary pool controls runoff from the design storm event. d. The temporary pool draws down in 2 to 5 days. !� .T e. If required, a 30-foot vegetative, filter is provided at the outlet (include non -erosive flow calculations) f. 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. A.-r It. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail). /4 :T, i. Vegetative cover above the permanent pool elevation is specified. /S ;T j. A trash rack or similar device is provided for both the overflow and orifice. �tSee ri�� k. A recorded drainage easement is provided for each basin including access to nearest right- J. ✓.) S'f' i c st of -way. A' : 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. d Scc afi� m. A mechanism is specified which will drain the basin for maintenance or an emergency. sG� 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 0 does not incorporate a vegetated filter at the outlet. This system (check one) 0 does ® does not incorporate pretreatment other than a forebay. Form S WU-102 Rev 3.99 Page 2 of 4 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. 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 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 79,88 feet in the main pond, the sediment shall be removed. 81.38 When the permanent pool depth reads feet in the forebay, the sediment shall be removed. BASIN DIAGRAM v Sediment Re oval EI. 81.38 Bottom Ele ation 80.00 FOREBAY ill in the blanks) Permanent Pool Elevation 85.50 Sediment Removal Elevation 79.88 -------------------------------------- Bottom Elevation 78.00 MAIN POND 75% 25 % 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 flashing of sediment through the emergency drain shall be minimized to the maximum extent practical. Form SWU-102 Rev 3.99 Page 3 of 4 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: Eliott Brown r�,-,.,a„ of Rxnansion Committee Address: 2164 Neill's Creek Road Lillington NC 27546 910-893-4490 'Date: 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, 1 �Chn 9 CScJ�iUrr� a Notary Public for the State of ilvr}hC�rv) �✓ County of Sqarm do hereby certify that hhez C M vfk 8rou— personally appeared before me this a5 day of Qch)btr , 2oa7 , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, *0 uw� o f• , t �aor�y. A "OU130G Ap, SEAL My commission expires n10W Z. QCVO Form SWU-102 Rev 3.99 Page 4 of 4 STORMWATER SUBMITTAL REQUIREMENTS . DETENTION POND Objective A. Collect all runoff from all BUA (proposed and/or existing and/oroffsite) as the case maybe, by any means including piping or swales, and direct it to the pond. B. Check the proposed pond design to make sure it meets or exceeds the minimum design criteria for surface area, volume and drawdown. If. What makes up a complete wet detention pond application package? LA/ Two sets of sealed, signed & dated layout & grading,4tans with ppropriate details. t. � Completed application with supplement(s), SWU-101, SWU-10 , SWU-104. Deed restriction document, if applicable (for subdivisions & projects with outparcels) r_D— Sealed, signed & dated calculations. III. Review Procedure A. APPLICATION An original signature is required. Photocopied signatures cannot be accepted.✓ �2! If an agent signs the application, a signed letter of authorization from the applicant must be provided which includes the name, title, mailing address and phone number of the person signing the letter. t.3--� A completed signed, dated and notarized wet detention pond supplement (SWU-102) with an original signature. t-4-- The numbers on the supplement match up to the numbers used in the calculations and shown on the plan details. jS Built -upon areas are reported in square feet in Section 111.6. 1eceiving stream name and classification. This is important because a wet pond cannot be used on a project that is within'/2 mile of and draining to SA waters. L-7� Section 111.6 is filled in -cannot be left blank. One column must be filled in for each proposed wet pond. —8�-- If the applicant is a corporation or LLC, look it up on the Secretary of State Corporations Database. Make sure corporation name is spelled correctly (capitalization and punctuation matter) and that the person signing the application is a member if the LLC if member -managed, or the manager if the LLC is manager -managed. Need documentation to support if the Articles of Incorporation do not list the members or managers of the LLC. 9:--�For subdivided projects, a signed and notarized deed restriction statement must be provided (Document "B") or a copy of the proposed deed restrictions in legal format from the attorney must be submitted containing the necessary statements (Document "A") B. CAJ.CULATIONS ,/ Excelspreadsheetats:\wqststormwater\excelspreadsheetslpondlsinglepondforthose projects that propose a single pond, and pond\multipleponds for those projects with 2-6 ponds. 2� The orifice is sized based on drawing down the 1" minimum volume in 2-5 days under V average head conditions. The average head is approximately one-half of the distance between the permanent pool elevation (PPE) and the elevation of the next available outlet. If an outlet is not provided at the calculated 1" storage elevation, then the average head is based on the elevation of the next available outlet above the PPE. The temporary pool elevation (TPE) to be reported on the supplement is also the elevation of the next available outlet above the permanent pool. The temporary pool volume (TPV) to report on the supplement is the volume between the PPE and the TPE. va� The average pond depth is between 3' and 6'. Parts of the pond can be deeper than 6', but in no case can the pond be less than 3' deep. The TSS chart being used, 85% (requires a vegetated filter) or 90% (no filter). ,45!' SA/DA ratio calculation. +6- Required surface area at permanent pool. rY Provided surface area at permanent pool (Based on pond dimensions) 4.8+ Required volume calculation. LY' Table of elevations, areas, incremental volumes and accumulated volumes for overall pond and for forebay, to verify volumes provided. 1 Calculations must be signed, sealed & dated. �`I 1. Drainage area and Built -upon area to each pond. t-' Forebay designed to hold 20% of the permanent pool volume. (Range of 18%-22% OK.) Non -erosive flow for 10 yr. storm in the vegetated filter, if using 85% TSS. NCDENR Stormwater BMP Manual Revised 07-02-07 Table 10-1 Surface Area to Drainage Area Ratio for Permanent Sizi Achieve 85 Percent TSS Pollutant Removal Efficiency in the Mountain an iedmont Re io , Adapted from Driscoll, 19Rf, Percent Impervious Cover 3.0 4.0 Permanent Pool Average Depth (ft) 5.0 6.0 7.0 8.0 9.0 10% 0.59 0.49 0.43 0.35 0.31 0.29 0.26 20% 0.97 0.79 0.70 0.59 0.51 0.46 0.44 30% 1.34 1.08 0.97 0.83 0.70 0.64 0.62 40% 1.73 1.43 1.25 1.05 0.90 0.82 0.77 50% 2.06 1.73 1.50 1.30 1.09 1.00 0.92 60% 2.40 2.03 1.71 1.51 1.29 1.18 1.10 70% 2.88 2.40 2.07 1.79 1.54 1.35 1.26 80% 3.36 2.78 2.38 2.10 1.86 1.60 1.42 90% 1 3.74 3.10 2.66 2.34 2.11 1.83 1.67 ) Table 10-2 Surface Area to Drainage Area Ratio for Permanent Pool Sizing to Achieve 85 Percent TSS Pollutant Removal Efficiency in the Coastal Region, Adapted from Driscoll, 1986 Percent Permanent Pool Average Depth (ft) Impervious Cover 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5' 10% 0.9 0.8 0.7 0.6 0.5 0 0 0 0 0 20% 1.7 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 30% 2.5 2.2 1.9 1.8 1.6 1.5 1.3 1.2 1.0 0.9 40% 3.4 3.0 2.6 2A 2.1 1.9 1.6 1.4 1.1 1.0 50% 4.2 3.7 3.3 3.0 2.7 2.4 2.1 1.8 1.5 1.3 60% 5.0 4.5 3.8 3.5 3.2 2.9 2.6 2.3 2.0 1.6 70% 6.0 5.2 4.5 4.1 3.7 3.3a 2.9 2.5 2.1 1.8 80% 6.8 6.0 5.2 4.7 4.2 3.7 3.2 2.7 2.2 2.0 90% 7.5 6.5 5.8 5.3 4.8 4.3, 3.8 3.3 2.8 1.3 100% 8.2 7.4 6.8 6.2 5.6 5.0 4.4 3.8 3.2 2.6 Wet Detention Basin 10-7 July 2007 C. PLANS �I" Development/Project Name Engineer name and firm. 3. Legend North Arrow Location Map with nearest intersection of two major roads shown. Major road is any 1, 2, • or 3 digit NC, US or interstate highway. Scale- standard engineering scale, no off-the-wall stuff. Date Revision number and date, if applicable. 1.9�- Original contours, proposed contours, spot elevations, finished floor elevations, pipe /inverts, swale inverts, etc. ✓f0 Existing drainage (piping, swales, ditches, ponds, etc.), including off -site. Include a map delineating the offsite drainage areas. 1 roperty/Project boundary lines, bearing & distances. i Mann Hinh Wntar I inn nr Alnrmnl Hinh %A/ntnr 1 inn-:F-�onlin�4.le ar d IV. of adjacent wetlands. Evaluate the need for a liner and/or berm/slurry wall to prevent dewaterino the wetland. ✓f3- Dranage e , pipe sizes and swale inverts are provided. rj14: Wetlands delineated, or a note on the plans that none exist. Get a copy of the wetlands delineation map signed by the Corps of Engineers, or have the applicant include a copy of the unsigned delineation map submitted to the Corps. Wet ponds may not be located in wetlands unless a permit to fill those wetlands has been obtained. GIs- Details for the roads, parking, cul-de-sacs, including sidewalk width, radii, dimensions & slopes. L%�Apartment / Condo development- Provide a typical building footprint with dimensions wand note all concrete and wood deck areas. "1T The drainage area for each wet pond is clearly delineated and numbered to match up to the calculations and supplement. Drainage area delineation is best done as a separate plan sheet. 18. A pond section detail to include the forebay, a 10' wide 6:1 or flatter vegetated shelf, pertinent elevations for the bottom, permanent pool�and temporary pool, 3:1 slopes above the permanent pool, and the weir elevation between the main pond and the forebay. —19. An outlet structure detail showing a trash rack with :54" square openings, the necessary orifice invert elevation (i.e., the permanent pool), orifice size and temporary pool elevation. Dimensions for each line and arc formed by the permanent pool contour. If the pond surface area is based on the 85% TSS chart, a 30' vegetated filter is required to be shown on the plans & detailed (elevations, inverts, slopes, and flow spreader mechanism). �. A forebay must be provided for each inlet. —z3: The pond must have a 3:1 length to width ratio. Extremely long, skinny ponds and square ponds are not acceptable because the SA/DA ratios used in the charts are based on Driscoll's model which assumed a 3:1 L:W ratio. Artificial "baffles" of timber, vinyl, or earth can be used to create a longer flow path. The top elevation of the baffle should be set at the temporary pool elevation o higher. L24' Vegetation is specified for the pond slopes and wetlands species are listed for planting on the 6:1 shelf. Weeping Love Grass is not suitable as a permanent vegetated cover for pond slopes. ,25 All roof drainage must be directed to the pond. Show the roof drain collection lines on the plan. This is especially necessary for projects where the buildings back up the property lines where roof drainage may leave the site prior to going through the pond. BIMS entry (for DWQ personnel only) Enter & track application acknowledged date, review date, addinfo requested/received dates, permit issue dates, and drainage area info. Best done after the addinfo letter is written and before sending permit up for signature. V. Shell documents (for DWQ personnel only) A. Requesting additional information: s:\wgs\stormwater\shells\addinfo B. Permit shells: s:\wqs\stormwater\highcompond s:\wgs\stormwater\highsubpond