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HomeMy WebLinkAboutSW7070138_CURRENT PERMIT_20070301STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. DOC TYPE rZV CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATEUjj7D?�/� l YYYYMMDD i r —I Y Mr. Robert C. Kemp, E & B Partnership PO Box 5154 ixo Michael F. Easley, Governor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources March 1, 2007 Managing Partner Henderson. NC 27537 Dear Mr. Kemp: Alan W. Klimek, P.E. Director Division of Water Quality Subject: Permit No. SW7070138 FMC-DS Windsor High Density Stormwater Project Bertie County The Washington Regional Office received a complete Stormwater Management Permit Application for FMC-DS Windsor on February 26, 2007. 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. SW7070138 dated March 1, 2007, for the construction of the subject project. This permit shall be effective from the date of, issuance until March 1, 2017, 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 and in the submitted application. Failure to establish an adequate system for operation and maintenance of the stormwater management system will result in future compliance problems. If any parts, requirements, or limitations contained in this permit are unacceptable, you have the right to request an adjudicatory hearing upon written request within thirty (30) days following receipt of this permit. This request must be in the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611- 7447. Unless such demands are made this permit shall be final and binding. If you have any questions, or need additional information concerning this matter, please contact either Scott Vinson, or me at (252) 946-6481. Sincere[ /,� , � AI Hod Regional Supervisor Surface Water Protection Section AH/sav: C:\STORMWATER\PERMIT\SW7070138 cc: Jon Meade — Bartlett Engineering & Surveying, PC �eertie County Building Inspections t/Washington Regional Office Central Files North Carolina Division of Water Quality Washington Regional Office Phone (252) 946-6481 FAX (252) 946-9215 Customer Service Internet: w%ew. ncwateraualitv.ora 943 Washington Square Mall, Washineon, NC 27889 1-877-623-6749 An Equal OpportunitylAf rmative Action Employer —50%Recycled/10% Post Consumer Paper N""oa��`hhCaro dvatural State Stormwater Management Systems Permit No. SV 7070138 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 E & B Partnership FMC-DS Windsor Bertie County FOR THE construction, operation and maintenance of a wet detention basin in compliance with the provisions of 15A NCAC 2H .1000 (hereafter referred to as the "stormwater rules') and the approved stormwater management plans and specifications and other supporting data as attached and on file with and approved by the Division of Water Quality and considered a part of this permit. This permit shall be effective from the date of issuance until March 1, 2017, 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 controls have been designed to handle the runoff from 1.97 acres of impervious area. 3. 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 and permit. 4. The tract will be limited to the amount of built -upon area indicated on page 3 of this permit, and per approved plans. Final plans, including drainage, for the built -upon area labeled as'Future' on the approved plans must be submitted and approved by the Division of Water Quality prior to the construction of the "Future" area. 5. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. The runoff from all built -upon area within the permitted drainage areas of this project must be directed into the permitted stormwater control system. Page 2 of 8 State Stormwater Management Systems Permit No. SV 7070138 The following design criteria have been provided in the wet detention pond and must be maintained at design condition: a. Drainage Area, acres: b. Total Impervious Surfaces, ft2: Future Lot Development, ft2: c. Design Storm, inches: d. Pond Depth, feet: e. TSS removal efficiency: f. Permanent Pool Elevation, FMSL: g. Permanent Pool Surface Area, ft2: h. Permanent Storage Volume, ft3: i. Permitted Forebay Volume, ft3: j. Temporary Storage Elevation, FMSL: k. Temporary Storage Volume, ft3: I. Controlling Orifice: M. Receiving Stream/River Basin: n. Stream Index Number: o. Classification of Water Body: II. SCHEDULE OF COMPLIANCE 2.36 85,808 33,850 1.0 3.00 90% 20.00 10,137 19,251 3,791 20.70 7,561 1.25" � pipe UT Cashie River / Roanoke 24-2-(1) "C; Sw" 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 Plans 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. Mowin.9 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 bypass structure, filter media, flow spreader, catch basins, piping and vegetated filter. g. A clear access path to the bypass structure must be available at all times. 4. Records of maintenance activities must be kept and made available upon request to authorized personnel of DWQ. The records will indicate the date, activity, name of person performing the work and what actions were taken. Page 3 of 8 State Stormwater Management Systems Permit No. SW7070138 5. The facilities. shall be constructed as shown on the approved plans. This permit shall become voidable unless the facilities are constructed in accordance with the conditions of this permit, the approved plans and specifications, and other supporting data. 6. Upon completion of construction, prior to issuance of a Certificate of Occupancy, and prior to operation of this permitted facility, a certification must be received from an appropriate designer for the system installed certifying that the permitted facility has been installed in accordance with this permit, the approved plans and specifications, and other supporting documentation. Any deviations from the approved plans and specifications must be noted on the Certification. A modification may be required for those deviations. 7. If the stormwater system was used as an Erosion Control device, it must be restored to design condition prior to operation as a stormwater treatment device, and prior to occupancy of the facility. 8. Access to the stormwater facilities shall be maintained via appropriate easements at all times. 9. The permittee shall submit to the Director and shall have received approval for revised plans, specifications, and calculations prior to construction, for any modification to the approved plans, including, but not limited to, those listed below: a. Any revision to any item shown on the approved plans, including the stormwater management measures, built -upon area, details, etc. b. Project name change. C. Transfer of ownership. d. Redesign or addition to the approved amount of built -upon area or to the drainage area. e. Further subdivision, acquisition, lease or sale of all or part of the project area. The project area is defined as all property owned by the permittee, for which Sedimentation and Erosion Control Plan approval or a CAMA Major permit was sought. f. Filling in, altering, or piping of any vegetative conveyance shown on the approved plan. 10. The permittee shall submit final site layout and grading plans for any permitted future areas shown on the approved plans, prior to construction. 11. A copy of the approved plans and specifications shall be maintained on file by the Permittee for a minimum of ten years from the date of the completion of construction. 12. The Director may notify the permittee when the permitted site does not meet one or more of the minimum requirements of the permit. Within the time frame specified in the notice, the permittee shall submit a written time schedule to the Director for modifying the site to meet minimum requirements. The permittee shall provide copies of revised plans and certification in writing to the Director that the changes have been made. 13. This permit shall be effective from the date of issuance until March 1, 2017. Application for permit renewal shall be submitted 180 days prior to the expiration date of this permit and must be accompanied by the processing fee. 14. No homeowner/lot owner/developer shall fill in, alter, or pipe any drainage feature (such as swales) shown on the approved plans as part of the stormwater management system without submitting a revision to the permit and receiving approval from the Division. 15. Prior to transfer of the permit, the stormwater facilities will be inspected by DWQ personnel. The facility must be in compliance with all permit conditions. Any items not in compliance must be repaired or replaced to design condition prior to the transfer. Records of maintenance activities performed to date will be required. Page 4 of 8 State Stormwater Management Systems Permit No. SW7070138 16. Prior to the sale of any lot, the following deed restrictions must be recorded: a. The following covenants are intended to ensure ongoing compliance with State Stormwater Management Permit Number SW7070138, as issued by the Division of Water Quality under NCAC 2H.1000. b. The State of North Carolina is made a beneficiary of these covenants to the extent necessary to maintain compliance with the Stormwater Management Permit. C. These covenants are to run with the land and be binding on all persons and parties claiming under them. d. The covenants pertaining to stormwater may not be altered or rescinded without the express written consent of the State of North Carolina, Division of Water Quality. e. Alteration of the drainage as shown on the approved plans may not take place without the concurrence of the Division of Water Quality. f. Construction of additional built -upon area in excess of 33,850 square feet, as noted in the permit and on the approved plans, will require a permit modification. g. All runoff on the lot must drain into the permitted system. h. Filling in or piping of any vegetative conveyances (ditches, swales, etc.) associated with this development, except for average driveway crossings, is strictly prohibited by any persons. 17. A copy of the recorded deed restrictions must be submitted to the Division within 30'days of the date of recording the plat, and prior to selling lots. The recorded copy must contain all of the statements above, the signature of the Permittee, the deed book number and page, and the stamp/signature of the Register of Deeds. 18. Built upon area includes, but is not limited to, structures, asphalt, concrete, gravel, brick, stone, slate, coquina and parking areas, but does not include raised, open wood decking, or the water surface of swimming pools. 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. Page 5of8 State Stormwater Management Systems Permit No. SW7070138 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. 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. 9. The permittee shall notify the Division any name, ownership or mailing address changes within 30 days. Permit issued this the 15` day of March, 2007. NORTH Awr=-� CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION f�— for 111p11 YY. 1\Illlllil\, 1 .L., VIIVV4V1 Division of Water Quality By Authority of the Environmental Management Commission Permit Number SW7070138 Page 6 of 8 i State Stormwater Management Systems Permit No. SW7070138 FMC-DS Windsor Stormwater Permit No. SW7070138 Bete 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. SW7070138 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 bypass structure elevations are per the approved plan. 6. The bypass structure is located per the approved plans. 7. A 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. All required design depths are provided. 13. All required parts of the system are provided. 14. The required system dimensions are provided per the approved plans. cc: NCDENR-DWQ Regional Office Bertie County Building Inspections State of North Carolina SVVAci� (/3 I /O RECEIVED Department of Environment and Natural Resources Division of Water Quality 9,r, "AN 3 1 2giORMWATER MANAGEMENT PERMIT APPLICATION FORM ®WQ-WAR® This form may he photocopied for use as an original I. GENERAL INFORMATION 1. Applicants name (specify the name of the corporation, individual, etc. who owns the project): E&B Partnership 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Bob KemD 0_1.. 1 r V __ M 1 A_ 1 3. Mailing Address for person listed in item 2 above: P.O. Box 5154 City: Henderson State: NC Zip: 27537 Telephone Number: ( 252 )- 492-0028 4. Project Name (subdivision, facility, or establishment name -should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): FMC-DS Windsor 5. Location of Project (street address): 1415 S. King St. (U.S Hwy 17) City: Windsor Bettie 6. Directions to project (from nearest major intersection): Approximately 800 feet west of the intersection of US Hwy 17 (King St) and NC Hwy 308 7. Latitude: 35.9876 N Longitude: 76.9258 W (NAD831WGS84) of project 8. Contact person who can answer questions about the project: Name: Jon Meade Telephone Number: ( 252 )-399-0704 II. PERMIT INFORMATION: 1. Specify whether project is (check one): X New Renewal Modification Form SWU-101 Version 3.99 Page 1 of 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 X 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 captured for all built upon area is directed to a wet detention basin. 2. Stormwater runoff from this project drains to the Roanoke River basin. 3. Total Project Area: 2.67 acres , 4. Project Built Upon Area: 73.8 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. To Pond Area Not to Pond Basin Information Drainage Areal Drainage Area 2 Receiving Stream Name UT to Cashie River UT to Cashie River Receiving Stream Class C;Sw C;Sw Drainage Area 2.358 Acres 0.312 Existing Impervious` Area 0.0 Acres 0.0 Acres Proposed Impervious*Area 1.97 Acres 0.0 Acres % Impervious* Area (total) 83.54 0.0 Acres Impervious* Surface Area Drainage Area 1 Drainage Area 2 On -site Buildings 8906 sq ft On -site Streets / Parking 38,212 sq ft On -site Future 1925 sq It On -site Sidewalks 2915 sq ft Other on -site Future Reserve 33,850 sq ft Off -site N/A Total: 85,808 sq ft/ 1.97 Acres Total: Impervious area is defined as the built upon area including, but not limited to, buildings, rack. narkina arras _ sidewalks, gravel areas, etc. Form SWU-101 Version 3.99 Page 2 of m 51 7. How was the off -site impervious area listed above derived? NIA IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS The following italicized deed restrictions and protective covenants are required to be recorded for all subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table listing each lot number, size and the allowable built -upon area for each lot must be provided as an attachment. 1. The following covenants are intended to ensure ongoing compliance with state stormwater management permit number !!�:fy 170? DI 3T 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 VI. SUBMITTAL REQUIREMENTS Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ). A complete package includes all of the items listed below. The complete application package should be submitted to the appropriate DWQ Regional Office. Please indicate that you have provided the following required information by initialing in the space provided next to each item. Initials Original and one copy of the Stormwater Management Permit Application Form One copy of the applicable Supplement Form(s) for each BMP Permit application processing fee of $420 (payable to NCDENR) Detailed narrative description of stormwater treatment/management Two copies of plans and specifications, including: - 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): Bartlett Engineering and Surveying, PC Mailing Address: 1906 Nash Street North Citv: Wilson State: NC Zio: 27893 Phone: ( 252 ) -399-0704 Fax: ( 252 ) -399-0804 VIII. APPLICANT'S CERTIFICATION I, (print or type name of person listed in General Information, item 2) certify that the information included on this permit application form is, to the best of my knowledge, correct and that the project will be constructed in conformance with the approved plans, that the required deed restrictions and protective covenants will be recorded, and that the proposed project complies with the requirements of 15A NCAC 2H .1000. P Forth SWU-101 Version 3.99 Page 4 of 4 Date: 1 . Xl. o7 Permit No. (to be provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality E CEIVED STORMWATER MANAGEMENT PERMIT APPLICATION F WET DETENTION BASIN SUPPLEMENT FEB 2 6 2007 This form may he photocopied for use as an original DWQ PROJ # 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: FMC-DS Windsor Contact Person: Jon Meade Phone Number: ( 252)-399-0704 For projects with multiple basins, specify which basin this worksheet applies to: N/A elevations Basin Bottom Elevation 17.0 ft. (floor of the basin) Permanent Pool Elevation 20.0 ft. (elevation of the orifice) Temporary Pool Elevation 20.7 ft. (elevation of the discharge structure overflow) areas Permanent Pool Surface Area 10137 I sq. ft. (water surface area at the orifice elevation) Drainage Area 2.358 ac. (on -site and off -site drainage to the basin) Impervious Area 1.97 ac. (on -site and off -site drainage to the basin) volumes Permanent Pool Volume 19251.1 cu. ft. (combined volume of main basin and forebay) Temporary Pool Volume 7560.5 cu. ft. (volume detained above the permanent pool) Forebay Volume 3790.9 cu. ft. (approximately 20% of total volume) Other parameters SA/DAI 9.86required/9.87 provided (surface area to drainage area ratio from DWQ table) Diameter of Orifice 1.25 in. (2 to 5 day temporary pool draw -down required Design Rainfall 1.0 in. Design TSS Removal 2 90 % (minimum 85% required) 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 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. c. The temporary pool controls runoff from the design storm event. d. The temporary pool draws down in 2 to 5 days. 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. h. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail). i. Vegetative cover above the permanent pool elevation is specified. j. A trash rack or similar device is provided for both the overflow and orifice. k. A recorded drainage casement is provided for each basin including access to nearest right- of-way. 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. In. A mechanism is specified which will drain the basin for maintenance or an emergency. III. WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if one is provided. This system (check one) 0 does of corporate a vegetated filter at the outlet. This system (check one) 0 does does n t incorporate pretreatment other than a forebay. Form SWU-102 Rev 3.99 Page 2 of 4 Maintenance activities shall be performed as follows: After every significant runoff producing rainfall event and at least monthly: a. Inspect the wet detention basin system for sediment accumulation, erosion, trash accumulation, vegetated cover, and general condition. b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within 2 to 5 days as designed. Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative cover to maintain a maximum height of six inches, and remove trash as needed. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to maintain proper functioning. 4. Remove accumulated sediment from the wet detention basin system semi-annually or when depth is reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality (i.e. stockpiling near a wet detention basin or stream, etc.). The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the permanent pool depth reads 2.25 When the permanent pool depth reads 3.0 feet in the main pond, the sediment shall be removed. feet in the forebay, the sediment shall be removed. BASIN DIAGRAM (fill in the blanks) 0 Permanent Pool Elevation 20.0 Sediment Re:ovalI. 17.0 75 0l. -------- - Sediment Removal Elevation17.75T2�5 Bottomn 16.0 % -----------------------------------------Bonom Elevation 17.0 FOREBAV MAIN POND 5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These plants shall be encouraged to grow along the vegetated shelf and forebay berm. 6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain shall be minimized to the maximum extent practical. Form SWU-102 Rev 3.99 Page 3 of 4 7. 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: J:�-'O(t. ke�t,'p Address: P.C. box 5is,4 } tit - ow mL .1-7sato Date: I 2 to c),7 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. /\ - � D/t e a Notary Public for the State of /1/t�'%/i ����[i/✓i1, County of V"—rK , do hereby certify that /SST (4, /cay personally appeared before me this ;�6— day of AV , and acknowledge the due maintenance requirements. Witness my hand and official seal, SEAL My commission expires 0 %"0 '-.-?0%U Form SWU-102 Rev 3.99 Page 4 of 4