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HomeMy WebLinkAboutGeneral Permits (6195)CERTIFICATION OF EXEMPTION FROM REQUIRING A CAMA PERMIT as authorized by the State of North Carolina, Department of Environment, Health, and Natural Resources and the Coastal Resources C in an area of environmental concern pursuant to 15 NCAC Subchapter 7K .0203. Applicant Name kc. t.t 1 'A j �F16, Q Address , r 1 'A U ke City State Project Location (County, State Road, Water Body, etc.) Type and Dimensions of Project The proposed project to be located and constructed as described above is hereby certified as exempt from the CAMA permit re- quirement pursuant to 15 NCAC 7K .0203?This exemption to CAMA permit requirements does not alleviate the necessity of your obtaining any other State, Federal, or Local authorization. Phone Number Zip This certification of exemption from requiring a CAMA permit is valid for 90 days from the date of issuance. Following expiration, a re-examination of the project and project site may be necessary to continue this certification. SKETCH (SCALE: ) I&C c,tkv.'r RbO% v { t=, f C �VNCr.'L 1. W\i?e&SA B,Lt j Wil%-ViV6-f : "I—L-C-i fit ! L`l;N yj >`11r I-n EC'tN 11 r: L .t ;=1a�Ul '�tl'si? 1:WiA-f 4'%}sl t�}A5�11atik3 ta7 C kJ S A `N 5 -T c s ifk } � �'t ri"C t. Q£C1 v A > _ rV*% V _S7T, i,�Cs E 1 '' - c pqc fLI±v $tlp5n1F_;� f1I-L_ Nm $k 1 k,.y26N Any person who proceeds with a development without the con- sent of a CAMA official under the mistaken assumption that the development is exempted, will be in violation of the CAMA if there is a subsequent determination that a permit was required for the development. The applicant certifies by signing this exemption that (1) the ap- plicant has read and will abide by the conditions of this exemp- tion, and (2) a written statement has been obtained from adjacent landowners certifying that they have no objections to the proposed work. Y ter. , !IV I!-/z1. /a 5- f-G Applicant's signature CAMA Official's signature Issuing date Expiration date Attachment: 15 North Carolina Administrative Code 7K .0203 September 30, 2005 Mr. Tim Ward, Partner Charter Building Group 1512 Burnett Road Wilmington, NC 28409 Subject: Stormwater Permit No Carolina Marina High Density Project New Hanover County Dear Mr. Ward: Michael F. Easley, Governor William G. Ross, Jr., Secretary North Carolina Department of Environment and Natural Resources SW8 040103 Alan W. Klimek, P.E. Director Division of Water Quality o C T 0 6 Z005 Morehead City L)cm The Wilmington Regional Office received a complete Stormwater Management Permit Application for Carolina Marina on September 21, 2005. 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 040103 dated September 30, 2005, for the construction of the subject project. This permit shall be effective from the date of issuance until September 30, 2015, 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. Sincerely, ,6 Edward Beck Regional Supervisor Surface Water Protection Section ENB/arl: S:\WQS\STORMWAT\PERMIT\040103.sep05 cc: James Fentress, P.E., Stroud Engineering Tony Roberts„ New Hanover County Building Inspections City of Wilmington Development Services Beth E. Wetherill, New Hanover County Engineering Doug Huggett, DCM Linda Lewis Wilmington Regional Office Central Files North Carolina Division of Water Quality 127 Cardinal Drive Extension Phone (910) 796-7215 Customer Service 1 -877-623-6748 Wilmington Regional Office Wilmington, NC 28405-3845 FAX (910) 350-2004 Internet: h2o.enr.state.nc.us One NorthCarolina An Equal Opportunity/Affirmative Action Employer — 50% Recycled/10% Post Consumer Paper Aatumllry State Stormwater Management Systems Permit No. SW8 040103 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 Tim Ward & Charter Buiding Group Carolina Marina Burnett Road, Wilmington, New Hanover County FOR THE construction, operation and maintenance of an underground infiltration trench 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 September 30, 2015, and shall be subject to the following specified conditions and limitations: I. DESIGN STANDARDS 1. This permit is effective only with respect to the nature and volume of stormwater described in the application and other supporting data. 2. This stormwater system has been approved for the management of stormwater runoff as described in Section 1.6 on page 3 of this permit. The stormwater control consists of 617 linear feet of 48" 0 RCP for storage, and an infiltration trench system. Runoff from the project is stored in the 48" pipes and is then pumped to the trench system via a Myers 4VC, 5 HP, submersible, capable of pumping 700 gpm at 14' of TDH. The system has been designed to handle the runoff from 44,806 square feet of impervious area, and must be operated with a 50' vegetated filter. 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. Page 2 of 7 State Stormwater Management Systems Permit No. SW8 040103 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. 6. The following design criteria have been provided in the infiltration trench and must be maintained at design condition: a. Drainage Area, acres: 2.87 Onsite, ft2: 125,017 Offsite, ft2: 0 b. Total Impervious Surfaces, ft2: 44,806 C. Design Storm, inches: 1.5 d. Trench Dimensions, L x W x H, ft: 95 x 35 x 2 e. Perforated Pipe Diameter/Length: 15" / 670 f. Bottom Elevation, FMSL: 6.5 g. Bypass Weir Elevation, FMSL: 5.5 (bypass from 48" 0 pipe) h. Permitted Storage Volume, ft3: 10,926 48" (D pipes, ft : 7,753 Infiltration trench, ft3: 3,173 i. Type of Soil: Newhan J. Expected Infiltration Rate, in/hr: 20 k. Seasonal High Water Table, FMSL: 4.11 I. Time to Draw Down, hours: 1 M. Receiving Stream/River Basin: ICWW / Cape Fear n. Stream Index Number: CPF24 18-87-(30.5) o. Classification of Water Body: "SA" 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. 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. Page 3 of 7 State Stormwater Management Systems Permit No. SW8 040103 4. 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. 5. 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 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. 6. 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 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. Page 4 of 7 State Stormwater Management Systems Permit No. SW8 040103 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. 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 30th day of September 2005. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION for Alan W'Klimek, P.E., Director Division of Water Quality By Authority of the Environmental Management Commission Page 5 of 7 State Stormwater Management Systems Permit No. SW8 040103 Carolina Marina Stormwater Permit No. SW8 040103 New Hanover 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 6 of 7 State Stormwater Management Systems Permit No. SW8 040103 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 Tony Roberts, New Hanover County Building Inspections Page 7 of 7 OFFICE USE ONLY Date Received Fee Paid Permit Number "- _ o 56, G`� C?i �? 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): Charter Building Group 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Tim Ward, Partner 3. Mailing Address for person listed in item 2 above: 1512 Burnett Rd. City: Wilmington State: NC Zip: 28409 Telephone Number: ( 910 ) 686-8100 4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Carolina Marina 5. Location of Project (street address): Burnett Road City: Wilmington County: New Hanover 6. Directions to project (from nearest major intersection): US 421 S from US421/NC132 to Burnett Rd., right on Burnett to Silver Ave., property on SE corner. 7. Latitude: N 3404' 29" Longitude: W 77 ° 53' 16" of project 8. Contact person who can answer questions about the project: Name: James H. Fentress, Jr., P.E. Telephone Number: L 910 815-0775 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 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. Stormwater will be collected in drop inlets and stored in undergroud pipes for treatment and release. 2. Stormwater runoff from this project drains to the Cape Fear River basin. 3. Total Project Area: 2.87 acres 4. Project Built Upon Area: 35 % 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. Basin Information Drainage Area 1 Drainage Area 2 Receiving Stream Name ICWW Receiving Stream Class SA Drainage Area 2.87 Existing Impervious* Area 5.366F (To be remove Proposed Impervious*Area % Impervious* Area (total) Impervious* Surface Area Drainage Area 1 Drainage Area 2 On -site Buildings On -site Streets On -site Parking 42,273 sf On -site Sidewalks 233 sf Other on -site 800 sf *Ramp Off -site Total: 4+, 806 sf Total: Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas, sidewalks, gravel areas, etc. Form SWU-101 Version 3.99 Page 2 of 4 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. 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 complete package 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. 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): Stroud Engineering, P.A. Mailing Address: 102—D Cinema Drive City:__ Wilmington Phone: ( 910 ) 815-0775 VIII. APPLICANT'S CERTIFICATION State: NC Fax: ( 910 Zip: 28403 815-0593 1, (print or type name of person listed in General Information, item 2) Tim Ward 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 Dater l • 2,3 - O4 Form SWU-101 Version 3.99 Page 4 of 4 Permit No. av 04c) �03 (to be provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM UNDERGROUND INFILTRATION TRENCH SUPPLEMENT This form may be photocopied for use as an original DWO Stormwater Management Plan Review: A complete stormwater management plan submittal includes a stormwater management permit application, an underground infiltration trench supplement for each system, design calculations, and plans and specifications showing all stormwater conveyances and system details. I. PROJECT INFORMATION Project Name : Carolina Marina Contact Person: James H. Fentress, Jr. P.E. Phone Number: (910 ) 815-0775 For projects with multiple infiltration systems, a supplement form must be completed for each system. This worksheet applies to: Trench 1 in Drainage Area 1 (from plans) (from Form SWU-101) II. DESIGN INFORMATION (attach supporting calculations/documentation): Soils Report Summary (based upon an actual field investigation and soil borings) Soil Type Newhan Infiltration Rate 20 in/hr or cf/hr/sf (circle appropriate units) SHWT Elevation 4.11 fmsl (Seasonal High Water Table elevation) Trench Design Parameters Design Volume 5,829 c.f. Design Storm 1.5 inch event (1.5 inch event for SA waters, I inch event for others) Drawdown Time 0.04 days Perforated Pipe Size 15 inch diameter Perforated Pipe Length 670 ft. No. Observation Wells -0- (may be required on a case -by -case basis) Stone Type (if used) #57 Stone Void Ratio 40% 48" Detention Pipe Parameters Trench Elevations (in feet mean sea level) Pipe Volume: 7, 753 cf Bottom Elevation 6-5 fmsl G�;im P34) Bottom Elevation: 0.00 Storage/Overflow Elevation 5.5 fmsl Overflow Eluvation: 5.5 (ArT Lf f Z�f21j, Form SWU-107 Rev 3.99 Page 1 of 4 Trench Dimensions Height Width 2.0 ft. 5.0 ft. III. REQUIRED ITEMS CHECKLIST Length Volume Provided 670 ft. 10,926 cu.ft. Trench: 3,173 Cf 48" Det. Pipe; 7,753 cf Total: 10,926 cf The following checklist outlines design requirements per the Stormwater Best Management Practices manual (N.C. Department of Environment, Health and Natural Resources, November 1995) and Administrative Code Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate that 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. Attach justification if a requirement has not been met. Applicants Initials a. System is located 50 feet from class SA waters and 30 feet from other surface waters. b. System is located at least 100 feet from water supply wells. c. Bottom of system is at least 2 feet above the seasonal high water table. d. Bottom of the system is 3 feet above any bedrock or impervious soil horizon. e. Off-line system, runoff in excess of the design volume bypasses the system (bypass detail provided). f. System is designed to draw down the design storage volume to the proposed bottom elevation under seasonal high water conditions within five days based upon infiltration through the bottom only (a hydrogeologic evaluation may be required). g. Soils have a minimum hydraulic conductivity of 0.52 inches per hour. Ll h. System is not sited on or in fill material or DWQ approval has been obtained. i. Plans ensure that the installed system will meet design specifications (constructed or restored) upon initial operation once the project is complete and the entire drainage area is stabilized. j. System is sized to take into account the runoff at the ultimate built -out potential from all surfaces draining to the system, including any off -site drainage. k. System is located in a recorded drainage easement for the purposes of operation and maintenance and has recorded access easements to the nearest public right-of-way. 1. System captures and infiltrates the runoff from the first 1.0 inch of rainfall (1.5 inch event for areas draining to SA waters ). in. Drainage area for the device is less than 5 acres. n. A pretreatment device ( filter strip, grassed swale, sediment trap, etc.) is provided. �-, - o. Trench bottom is covered with a layer of clean sand to an average depth of 4 inches. p. Sides of the infiltration trench are lined with geotextile fabric. q. Rock used is free of fines (washed stone) and has a large void ratio. :7u� r. Side to bottom area ratio is less than 4:1. z Form SWU-107 Rev 3.99 Page 2 of 4 s. Observation well(s) are provided (case -by -case basis). ?� t. Vegetated filter is provided for overflow (50 feet for SA waters, 30 feet for other waters) and detail is shown on plans. i u. A benchmark for checking sediment accumulation is provided. IV. UNDERGROUND INFILTRATION TRENCH OPERATION AND MAINTENANCE AGREEMENT 1. After every runoff producing rainfall event and at least monthly inspect the bypass/overflow structure for blockage and deterioration and the infiltration system for erosion, trash accumulation, grass cover, and general condition. 2. Repair eroded areas immediately, re -seed as necessary to maintain adequate vegetative cover, mow vegetative cover to maintain a maximum height of six inches, and remove trash and blockages as needed to maintain system perfonnance. Remove accumulated sediment annually or when depth is reduced to 75% of the original design depth. Restore depth to original design depth without over -excavating. Over -excavating may cause the required water table separation to be reduced and may compromise the ability of the system to perform as designed. 4. The water level in any monitoring wells will be recorded after a 1 inch rainfall event and at least once a month. Chronic high water table elevations (within 1 foot of the bottom of the system for a period of three months) shall be reported to DWQ immediately. If DWQ determines that the system is failing, the system will immediately be repaired or replaced to original design specifications. If the system cannot be repaired to perform its design function, other stormwater control devices as allowed by NCAC 2H .1000 must be designed, approved and constructed. Remove accumulated sediment from the infiltration system annually or when depth in the unit is reduced to 75% of the original design depth. The system shall be restored to the original design depth without over - excavating. Over -excavating may cause the required water table separation to be reduced and may compromise the ability of the system to perform as designed. Removed sediment shall be disposed of in an appropriate manner and shall not be handled in a manner that will adversely impact water quality (i.e. stockpiling near a stormwater treatment device or stream, etc.). A benchmark shall be established in the infiltration system. The benchmark will document the original design depth so that accurate sediment accumulation readings can be taken. The measuring device used to determine the depth at the benchmark shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the depth at the benchmark reads &,,38 , the accumulated sediment shall be removed from the system. Form SWU-107 Rev 3.99 Page 3 of 4 I acknowledge and agree by my signature below that I am responsible for maintaining the stormwater collection system in accordance with the six 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: Tim Ward, Partner Address: 1512 Burnett Road, Wilmington, NC 28405 Phone: 910— 68 6—RO0 Date: 4-11-05 Sianature.�� 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. a Notary Public for the State of NmzU -� 6g261Lv- ,, ounty of Jaw fL4tVs-VZ -, do hereby certify that I b,,+k v-,14 -w personally appeared before me this [04 day of 2�"t'`` , and acknowledge the due execution of the forgoing infiltration basin maintenance requirements. Witness my hand and official seal, I,pt, 1 , 1p>- y"L` `ems XU s My commission expires t CO ray'$..rY/aVVVIDDvA,�'��sy�•Joa��� �,��ld�'`1 Form SWU-107 Rev 3.99 Page 4 of 4