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HomeMy WebLinkAboutSW7060926_CURRENT PERMIT_20070212STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW��,Q DOC TYPE CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE P) YYYYMMDD 5 MS-1 Michael F. Easley, Governor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources DIVISION OF WATER QUALITY February 12, 2007 Mr. Bernice J. Ballance PO Box 69 Buxton, NC 27920 Subject Dear Mr. Balance: Alan W. Klimek, P.E. Director Division of Water Quality Stormwater Permit No. SW7060926 CAP'N B's Campgroung High Density Stormwater Project Dare County The Washington Regional Office received your completed Stormwater Application for the subject project on February 8, 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. SW7060926 dated February 12, 2007 to Mr. Bernice J. Ballance. This permit shall be effective from the date of issuance until February 12, 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. 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. North Carolina Division of Water Quality Internet h2o.enr.state.nc.us 943 Washington Square Mall Phone: 252-946-6481 Washington, NC 27889, FAX 252-946-9215 An Equal Opportunity/Affrmatve Acton Employer — 50% Recycled110% Post Consumer Paper Nne orthCarolina JVaturallry Mr. Bernice J. Ballance February 12, 2007 Page Two If you have any questions, or need additional information concerning this matter, please contact Mr. Bill Moore at (252)948- 3919. ,, ncerely, A Al Jd"geRegal.Su ervisor onP Surface Water Protection Section Washington Regional Office cc: Performance Engineering Dare County Planning/Inspections -,4ARO Stormwater Files Central Files State Stormwater Management Systems Permit No. SW7060926 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 Mr. Bernice J. Ballance Dare County FOR THE construction, operation and maintenance of stormwater management systems 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 for (2) infiltration basins to serve CAP'N B's Campground located off SR1232 (Buxton Back Road) at Buxton, NC. This permit shall be effective from the date of issuance until February 12, 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 on page 4 of this permit, the Project Data Sheet. 3. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. 3 DIVISION OF WATER QUALITY PROJECT DATA Project Name: Permit Number: Location: Applicant: Mailing Address: Application Date: Water Body Receiving Stormwater Runoff: Classification of Water Body: Total Site Area: Total Impervious Surfaces Allowed: Basin Depths: Required Storage Volume: Provided Storage Volume: Provided Surface Area: Storage Elevations: 0 CAP'N B's Campground SW7060926 Dare County Mr. Bernice J. Ballance PO Box 69 Buxton, NC 27920 09/27/2006; original 02/08/2007; complete UT -Pamlico Sound SA 6.29 acres 43,666 sf 1.50 - Basin A 1.50 - Basin B 5794 cf - Basin A 4699 cf - Basin B 12,460 cf - Basin A 10,102 cf - Basin B 7343 sf - Basin A 5527 sf - Basin B 4.0 ft for both Basins 4. No homeowner/lot owner/developer shall be allowed to fill in, alter, or pipe any vegetative practices (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. 5. The following items will require a modification to the permit: a. Any revision to the approved plans, regardless of size b. Project name change C. Transfer of ownership d. Redesign or addition to the approved amount of built - upon area e. Further subdivision of the project area. In addition, the Director may determine that other revisions to the project should require a modification to the permit. 6. 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. II. SCHEDULE OF COMPLIANCE 1. The permittee will comply with the following schedule for construction and maintenance of the stormwater management system. a. 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 surfaces except roads. b. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately. 2. The facilities must be properly maintained and operated at all times. The approved Operation and Maintenance Plan must be followed in its entirety and maintenance must occur at the scheduled intervals. 3. The permittee shall at all times provide the operation and maintenance necessary to assure the permitted stormwater system functions at optimum efficiency including, but not limited to: 5 a. Semi-annual scheduled inspections (every 6 months) b. Sediment removal C. Mowing and revegetation of side slopes d. Immediate repair of eroded areas e. Maintenance of side slopes in accordance with approved plans and specifications f. Debris removal and unclogging of outlet structure, orifice device and catch basins and piping. 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. 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 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. Mail the Certification to the Washington Regional Office, 943 Washington Square Mall, Washington, North Carolina, 27889, attention Division of Water Quality. 7. A copy of the approved plans and specifications shall be maintained on file by the Permittee for a minimum of five years from the date of the completion of construction. III. GENERAL CONDITIONS 1. This permit is not transferable. In the event there is a desire for the facilities to change ownership, or there is a name change of the Permittee, a formal permit request must be submitted to the Division of Water Quality accompanied by an application fee, 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. 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 143-215.6(a) to 143-215.6(c). 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) which have jurisdiction. 6 r 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 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. 6. At least 6 months prior to the expiration date, the permittee shall request that this permit be renewed. Permit issued this the 12 th day of February, 2007. NORTH CAROLINA ENVIRONMENTAL Alan W. K imek, .E., Director Division of Water Quality By Authority of the Environmental Permit Number SW7060926 7 COMMISSION Management Commission Stormwater Permit SW7060926 (2) Infiltration Basins CAP'N B's Campground Buxton, NC Designer's Certification as a duly registered Professional Engineer in the State of North Carolina, having been authorized to observe (periodically/weekly/full time) the construction of the project, for (Project) (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. Signature Registration Number Date M ®WQ_WAI State of North Carolina epartment o dV �'aQ Df Environment and Natural Resources 2� Division of Water Quality q'y7�Ob 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): 8a_.rnlc:a T hall ��lr� 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): err f c a T 8 aJ1,3 iu 4_ 3. Mailing Address for person listed in item 2 abode: City: State: N Zip: 27920 Telephone Number: f Z 5 2 ) C% ZJ 3 4. Project Name (subdivision, facility, or establishment name -should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): 5. Location of Project (street address): l City: Uk_ f 0':1 County: /)ry f. p 6. Directions to project (from nearest major intersection): L Sk /232 /bp „?�dS Cjs7 of KOSSGJ"V � v 7. Latitude:/t( 3S� %.� 5 .�, r� Longitude: jj(, 7Sa 32 I /S-, r of project S. Contact person who can answer questions about the project: Name:9,6ead 1: .�i!, PC Telephone Number: (J,S 2, ) 4'0 193,5¢ II. PERMIT INFORMATION: 1. Specify whether project is (check one): ✓ 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 SW IN 012-6 and its issue date (if known) PV-Whi N 4 3. Specify the type of project check one): _Low Density High Density _Redevelop _General Permit _Other 4. Additional Project Requirements (check applicable blanks): _LAMA Major LSedimentation/Erosion Control _404/401 Permit _NPDES Stormwater Information on required state permits can be obtained by contacting the Customer Service Center at 1-577-623-6745. 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 pn,ject . 2. Stormwater runoff from this project drains to the p it ; r Utdz vs Y, River basin. ` /� 3. Total Project Area: 7. �3 acres 4. Project Built Upon Area: Z9� % 5. How many drainage areas does the project have? 2 6. Complete the following information for each drainage area. If there are more than two drainage areas in the project, attach an additional sheet with the information for each area provided in the same format as below. R/ICIAi R Basic Infoii iation ' bxx 77Dramage Aiea 1 S£ ",F e Dramage Area 2 Receiving Stream Name 0.<, w. E E cE Receiving Stream Class.S A Drainage Area Existing Impervious* Area Proposed Irn ervious Area et ? 6 1, 6 j %Impervious* Area (total) 30, ' `' z 7. 9 c Impervious` -Surface A ea Dra nage Aieala Drainage Area_ 2 On -site Buildings f� On -site Streets 27 656F 19, 136 On -site Parking On -site Sidewalks Other on -site Off -site rJj Total: F Total: 34 Impervious area is defined as the built upon area including, but not tinrited to, buildings, roads, parking areas, sidernalks, gravel areas, etc. Form S11'U-101 Version 3.99 Page 2 of 4 Ho,v wJ•as the off -site impervious area listed above derived? Z U i (LG d'y_8 r'a' / ct l 7 t z n Yr7,1T 111E C2hd( Ma7r, 0ti- <'17/ini1bd, Ln/ !'77hnd�< _l i.,,i na✓L,, n.. cnrr• . 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 follorving number_ covenants are intended to ensure ongoing compliance with state stormwater management pem,it 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 ,S SZ square feet of any ion s))wll be covered by stnnctures or impervious materials. Impervious materials include asphalt, gravel, concrete, brick, stone, slate or similar naterial but do not include wood decking or the water surface of swinaning 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 storrnwater management permit modification prior to construction. 5. All permitted runoff from outparcels or future development shall be directed into the permitted stor»uaater control system. These connections to the stormwater control system shall be performed in a manner flat maintains the integrity and performance of the system as pemnitted. 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 allparties 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 Stormw•ater 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 FormSWU-104 Low Density Supplement Form SWU-105 Curb Outlet System Supplement Form SWU-106 Off -Site System Supplement Fora. SWU-107 Underground Infiltration Trench Supplement Form SWU-108 Neuse River Basin Supplement Form SIVU-109 Innovative Best Management Practice Supplement Form SWU-101 Version 3.99 Pa.-e 3 of 4 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 submitt d to the appropriate DWQ Regional Office. 1. Mel indicate that you have provided the following required information by initialing in the space provided next to each item. In tials • Original and one copy of the Stormwater Management Permit Application Form • One copy of the applicable Supplement Form(s) for each BMf • Permit application processing fee of S"-_20 (payable to NCDENR) ; • Detailed narrative description of stormwater treatment/management • Tt,vo copies of plans and specifications, including: - Development/Project name - Engineer and firm' - Legend - North arrow - Scale ✓ - Revision number k date " - Mean high water line rv/f - 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 001 - Drainage areas delineated r o A -, E NTi zE S t T -Vegetated buffers (whererequired) tilfA VII. AGENT AUTHORIZATION If you wish to designate authority to another individual or firm so that they may proN',ide information on your behalf, please complete this section. Designated agent (individual or Mailing Address:t?uW V City: State: W C zip: ��(o Phone: (IS Fax: VIII. APPLICANT'S CERTIFICATION I,(print ortype name ofper;onliaedinGeneral Informal ion, item.2) Rn�h\C� J • ����c�V\CO. certify, that the information included on this perm t application form is, to the best of my knowledge, correct and that the project will be constructed in conformance ;,. ith 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. Signatu Form SWU•101 Version 3.99 Page 4 of 4 Date: v LETTER OF TRANSMITTAL PERFORMANCE ENGINEERING 8604 CARATOKE HIGHWAY POWELLS POINT, NC 27966 PHONE 252-491-8354 FAX 252-491-5112 CERTIFIED — RETURN RECEIPT REQUESTED TO: Mr. Bill Moore DATE: 12/29/06 OF: NCDENR-DWQ-WaRO 943 WASHINGTON SQUARE MALL WASHINGTON, NC 27889 JAN 0 3 2007 DWQ-WAR® PROJECT NUMBER: 978, CAP'N B'S CAMPGROUND, BUXTON, DARE COUNTY, PERMIT NUMBER SW7060926 WE TRANSMIT THE FOLLOWING: -Original + I copy- STORMWA TER MANAGEMENT PERMIT APPLICATION FORM -Two copies, Plan Sheet 5 of 5 -One each, INFILTRATION BASIN SUPPLEMENT, for Basins "A" & `B" - Original, Project Narrative - Original, Soils Report -Original, STORMWA TER BMP DESIGN CALCULATIONS COMMENTS: Bill, I have only submitted thepla BMP. The change to high density will require that don't want to proceed wit that exercise ant e e) sure the stormwater plan will be approved with no which depicts the tem and I i until I am Nothing pertaining to the sewerage system changes will impact coverage or any other stormwater related issues. Please let me know as soon as possible if you have any questions or concerns regarding this revised plan. Thanks and best regards, Bob Stewart CC: Mr. Bernice J. Ballance Permit No. (to be provided by DIV& State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM 47 :"jj INFILTRATION BASIN SUPPLEMENT This form may be photocopied for use as an original JAN 0 3 2007 DWO Stormwater Management Plan Review: rt:'^_'� � A complete stormwater management plan submittal includes a stormwater management permityaplilA,-? n, an infiltration basin supplement for each system, design calculations, soils report and plans and specifications showing all stormwater conveyances and system details. I. PROJECT INFORMATION Project Name: CAP' W g` S C, A M P CjIjZ o 0 to 1�> Contact Person: Rc?6yt -S . S&a oa - tIf. QT, • Phone Number: (ZSZ Xs — This worksheet applies to: Basin No. A in Drainage Area _A (as identified on plant) (from Form SIVU-101) I1. DESIGN INFORMATION - Attach supporting calculations/documentation. The soils report must be based upon an actual field investigation and soil borings. County soil maps are not an acceptable source of soils information. All elevations shall be in feet mean sea level (fmsl). Soils Report Summary Soil Type Infiltration Rate SHWT Elevation Basin Design Parameters Design Storm Design Volume Drawdown Time Basin Dimensions Basin Size Basin Volume Provided Basin Elevations Bottom Elevation Storage Elevation Top Elevation Fetes 6 •D - Z 0. Q 1 r r cf/hr/sf (circle appropriate units) Q, 83 ' fmSI (Seasonal High Water Table elevation) it inch (1.5 inch event for SA waters, 1 inch event for others) c.f. days IRRE6ULAR y'eomt72y(^' ft. x 12.4� 6a c.I. Z.S t fmsl 4, o ` fmsl 4. Z ` fills] srk�34) sq. ft. (bottont dimensions) 2• S' G'aNrdvR Form SWU-103 Rev 3.99 Page I of 3 Ill. la QUIRED FULMS CHECKLIST l The following checklist outlines design requirements per the Stormcvater Best Management Practices Manual (N.C. Department of Environment, Health and Natural Resources, February 1999) and Administrative Code Section: 15 A NCAC 211 .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 Stomiwater Management Permit Application Form, the agent may initial below. Attach justification if a requirement has not been met. Applicants Initials d' `' a. System is located 50 feet from class SA waters and 30 feet from other surface waters. QQ� 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. System is not sited on or in fill material or DWQ approval has been obtained. tl f. System is located in a recorded drainage casement for the purposes of operation and maintenance and has recorded access easements to the nearest public right-of-way. IQ S g. Drainage area for the device is less than 5 acres. _ K4� It. Soils have a minimum hydraulic conductivity of 0.52 inches per hour and soils report is attached. i. System captures and infiltrates the runoff from the first 1.0 inch of rainfall (1.5 inch event for areas draining to SA waters ). Design volume and infiltration calculations attached. 24-- s 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. Calculations attached. k 1p - M. a All side slopes stabilized with vegetated cover are no steeper than 3:1 (H:V). A pretreatment device such as a catch basin, grease trap, filter strip, grassed Swale or sediment trap is provided. Bottom of the device is covered with a layer of clean sand to an average depth of 4 inches or dense vegetative cover is provided. Vegetated filter is provided for overflow and detail is shown on plans (Required minimum length is 50 feet for SA waters, 30 feet for other waters). Flow distribution mechanism within the basin is provided. p. A benchmark is provided to determine the sediment accumulation in the pretreatment device. K, S'' ."' E g4s - r Runoff in excess of the design volume bypasses off-line systems (bypass detail provided). Systern is designed to draw down the design storage volume to the proposed bottom elevation under seasonal high water conditions within five days. A soils report and all pertinent draw -down calculations are attached. s. Plans ensure that the installed systean will meet design specifications (constructed or restored) upon initial operation once the project is complete and the entire drainage area is stabilized. Form SWU-103 Rev 3.99 Page 2 of 3 IV. INFILTRATION BASIN OPERATION AND MAINTENANCE AGREEMENT I. After every runoff producing rainfall event and at least,monthly inspect the infiltration system for erosion, trash accumulation, vegetative cover, and general condition. 2. Repair eroded areas immediately, re -seed as necessary to maintain adequate vegetative cover, mow vegetated cover to maintain a maximum height of six inches, and remove trash as needed. 3. After every runoff producing rainfall event and at least monthly inspect the bypass, inflow and overflow structures for blockage and deterioration. Remove any blockage and repair the structure to approved design specifications. Remove accumulated sediment from the pretreatment system and infiltration basin annually or when depth in the pretreatment 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 pretreatment unit. 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 design depth reads . r� feet in the pretreatment unit, the sediment shall be removed from both the pretreatment unit and the infiltration basin. If the Division determines that the system is failing, the system will immediately be repaired to original design specifications. If the system cannot be repaired to perform its design function, other stormwater control devices as allowed by NCAC 2FI .1000 must be designed, approved and constructed. I acknowledge and agree by my signature below that 1 am responsible for the performance of the five 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: 31z ic. ;cc Beg dance Owylrt jr Address: D"Itp Signature:! Note: The legally responsible party sbou d not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. t, ee_T l V—k t Q&e I a Notary Public for the State of N C County of tA2r , do hereby certify that _T;EVZN 10E T- _P5 A 1-LAYICC personally appeared before me this J�"74� day of and acknow edge t e due execution of the forgoing infiltration basin maintenance requirements. Witness my hand and official sea47 , SEAS M commission expires -C' a06 Form SWU-I03 Rev'3.99 Page 3 of 3 Permit No. (to be provided by DW& State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM j NE INFILTRATION BASIN SUPPLEMENT This forni nmy be photocopied for use as an original JAN 0 3 2007 DWO Stormwater Management Plan Review:N r��f y Qn�A�� A complete stormwater management plan submittal includes a stormwater management permit application, an infiltration basin supplement for each system, design calculations, soils report and plans and specifications showing all stormwater conveyances and system details. I. PROJECT INFORMATION Project Name : CAP' f`I R' S CAMPG i) ) MD Contact Person: Qob f -T. t-St,,U. Phone Number: (7--52 14ht fs35� This worksheet applies to: Basin No. _P�l in Drainage Area _�__ (as identified on plans) (from Form SIVU-101) II. DESIGN INFORMATION -Attach supporting calculations/documentation. The soils report must be based upon an actual field investigation and soil borings. County soil maps are not an acceptable source of soils information. All elevations shall be in feet mean sea level (fmsl). Soils Report Summary Soil Type 'FYi bo Infiltration Rate 4.0 -, Z.O. O in/hr r cf/hr/sf (circle appropriate units) SHWT Elevation I.13 fmsl_.(SeasonalHig?JaterTable elevation) Basin Design Parameters Design Storm Design Volume Drawdown Time Basin Dimensions Basin Size Basin Volume Provided Basin Elevations Bottom Elevation Storage Elevation Top Elevation Form SWU-103 Rev 3.99 inch(1.5 inch eventfor SA waters, I inch eventfor others) �-r c.f. A . 1 days iRRE4Ul.AR GEoM'`?Ri ft. x /O 02 c.f. 2 . s , fmsl 4. 0 - fmsl 9 flnSl Page I of 3 ft. = 5 � 5 21 sq. ft. (bottom dimensions) 2-6t cog-TaUP, 111. REQUIRED I'ITNIS CIILCKLIS"1' F. The following checklist outlines design requirements per the Slorntvvafer Best Management Practices Manual (N.C. Department of Environment, Health and Natural 'Resources, February 1999) and Administrative Code Section: 15 A NCAC 21-1 .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 Stonnwater Management Permit Application Form, the agent may initial below. Attach justification if a requirement has not been met. Applicants Initials' a" Qa6 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. o C. Bottom of system is at least 2 feet above the seasonal high water table. d. Bottom of the system is 3 feel above any bedrock or impervious soil horizon. e. System is not sited on or in fill material or DWQ approval has been obtained. f. System is located in a recorded drainage casement for the purposes of operation and maintenance and has recorded access easements to the nearest public right-of-way. R%S _ g. Drainage area for the device is less than 5 acres. It. Soils have a minimum hydraulic conductivity of 0.52 inches per hour and soils report is attached. i. System captures and infiltrates the runoff from the first 1.0 inch of rainfall (1.5 inch event for areas draining to SA waters ). Design volume and infiltration calculations attached. QO� 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. Calculations attached. RDc� k. All side slopes stabilized with vegetated cover are no steeper than 3:1 (H:V). A pretreatment device such as a catch basin, grease trap, filter strip, grassed swale or sediment trap is provided. skojQ. - SL..'F ff�J NS - m. Bottom of the device is covered with a layer of clean sand to an average depth of 4 inches or dense vegetative cover is provided. n. Vegetated filter is provided for overflow and detail is shown on plans (Required minimum length is 50 feet for SA waters, 30 feet for other waters). OFlow distribution mechanism within the basin is provided. QO p. A benchmark is provided to determine the sediment accumulation in the pretreatment D device. q. Runoff in excess of the design volume bypasses off-line systems (bypass detail provided). Q6 r. System is designed to draw down the design storage volutiie to the proposed bottom elevation under seasonal high water conditions within five days. A soils report and all pertinent draw -down calculations are attached. s. 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. Form SWU-103 Rev 3.99 Page 2 of 3 IV. INFILTRATION BASIN OPERATION AND MAINTENANCE AGREEMENT 1. After every runoff producing rainfall event and at least monthly inspect the infiltration system for erosion, trash accumulation, vegetative cover, and general condition. 2. Repair eroded areas immediately, re -seed as necessary to maintain adequate vegetative cover, mow vegetated cover to maintain a maximum height of six inches, and remove trash as needed. 3. After every runoff producing rainfall event and at least monthly inspect the bypass, inflow and overflow structures for blockage and deterioration. Remove any blockage and repair the structure to approved design specifications. 4. Remove accumulated sediment from the pretreatment system and infiltration basin annually or when depth in the pretreatment 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 pretreatment unit. 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 design depth reads feet in the pretreatment unit, the sediment shall be removed from both the pretreatment unit and the infiltration basin. 5. If the Division determines that the system is failing, the system will immediately be repaired 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. I acknowledge and agree by my signature below that I am responsible for the performance of the five 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: 9 ✓n ice 3 7 It 2 nCy� 01Jp � ' • A '��VA t._ _0 1 e1—, Si —nature:/ O Note: The legally responsible party shou d 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. p3E M F-i • 0 t DCTEt I a Notary Public for the State of W C— —County of 1 C)A o_15 —,do hereby certify that � P i61 Ce �• �t4LL_A nel✓ personally appeared before me this Q 7 day of � ei1em )xY' , 2tdd2, and acknow diet e due execution of the forgoing infiltration basin maintenance requirements. Wimess my hand and official seal, / A 'cI/LC .o SEAL. -' My commission expires Form SWU-103 Rev 3.99 Page 3 of 3 I'aVt- L U JAN 0 3 2007 CAP'N. B's CAMPGROUND ��JITAAR0 VILLAGE OF BUXTON — HATTERAS ISLAND — DARE COUNTY — NC ENGINEER'S PROJECT NUMBER 978 December 27, 2006 HIGH DENSITY STORMWATER BMP — PROJECT NARRATIVE Cap'n. B's Campground is a 56 site facility proposed for construction on a 6.293 acre tract (404 wetlands excluded) located in the Village of Buxton, on Hatteras Island, Dare County. The tract is essentially clear with widely scattered trees and bushes. The prevailing soil types are fine sands in the Corolla and Fripp series. Pursuant to the requirements of the NCDENR Division of Environmental Health a licensed Soil Scientist was retained by the owner to conduct a site soils evaluation and groundwater mounding analysis. A copy of the report prepared by Mr. E. Scott Stone, LSS of Environmental and Soil Service, Inc. was previously submitted with the STORMWA TER MANAGEMENT PERMIT APPLICATION FORM to fulfill the requirements for soils investigation. The original application was based on low density development as the BMP. The Div. of Water Quality ruling regarding the classification of the adjacent ditches and ponds necessitated the implementation of infiltration basins as the BMP. Supplemental soils investigation was conducted on December 20, 2006 in the specific areas proposed for infiltration basins. A report summarizing this investigation is included in the high density BMP application package. The site is essentially flat towards the rear (south) of the property while sloping at approximately 2% from north to south in the first approximately 160 feet. There are three existing ponds located along the south property line. These ponds separate the campground property from the tract owned and resided on by the project owner Mr. Bernice Ballance. To the east there is a broad expanse of 404 wetlands which has historically received runoff from the site. To the west, along the west property line is a drainage swale which drains to the previously mentioned ponds. An outfall ditch extends westerly from the string of ponds to an expansive swampy area known as Jeanette's Sedge.. The proposed BMP will consist of two shallow infiltration basins, one on the east side and one on the west side. The attached calculation sheet provides a breakdown of the size of each drainage area, the percentage of impervious coverage and the volumetric capacity of each basin. The basins are designed with a bottom elevation of 2.5'. This results in a separation from the seasonal high water table of 1.67' for Basin A and 1.37' for Basin B. To mitigate the reduced vertical separation distance, the basins have been designed for a three inch rainfall event, twice the volume required by the prevailing regulations. Both basins have capacity to store in excess of 100% of the design run-off volume. The site grading is designed to provide gentle sloping to convey stormwater run-off to the basins via sheet flow across the primarily vegetated site. All of the roadways are to be gravel which, although considered impervious, are significantly more conducive to infiltration than are hard surface pavements. One road side swale is provided to collect and convey run-off generated within the most southerly lots, adjacent to the existing ponds. The volume of storage available Narrative, 12/27/06, Cap'n. B's Campground, p.n.978, page 2 of 2 within this roadside swale is not included in the basin volume calculations. The swale and connecting culverts will provide an additional 2,198 cubic feet of storage volume. Each campsite will be limited to one 10' x 20' gravel parking space and one 7' x 14' pervious, wood framed, open deck. These limitations are imposed by the Dare County Zoning Ordinance. The impervious coverage calculations are also based on each site including an 8' x 44' camper, the maximum size for a "street legal" camper. bI- ✓• STE`NP%%k I1,/Z-7 PERFORMANCE ENGINEERING 8604 CARATOKE HIGHWAY POWELLS POINT, NC 27966 PH. 252-491-8354 FAX 252-491-5112 CAP'N. B'S CAMPGROUND STORMWATER BMP DESIGN CALCULATIONS DECEMBER 27, 2006 ENGINEER'S PROJECT NUMBER 978 JAN 0 3 2007 IA R0 INFILTRATION BASIN "A" Total drainage area = 144,849 s.f. (see basin boundary delineation, plan sheet 5 of 5) Impervious coverage: gravel roadway- 27,658 s.f. parking spaces- 10' x 20' x 29 sites = 5,800 s.f. campers- 8' x 44' x 29 sites = 10,208 s.f. TOTAL IMPERVIOUS COVERAGE = 43,666 S.F. (30.1%) Design for 3" rainfall event, calculate unit volume, using Schuler equation- Rv = 0.05 + 0.009(30.1) = 0.32 inches per inch I „- s 7q9' ! 6X 170 Design volume = 144,849 s.f. x 3"/12 x 0.32 = 11,588 c.f. basin capacity: 4' contour area = 9,270 s.f.; 2.5' contour area = 7,343 s.f. basin capacity = 7,343 s.f(1.5') + (9,270 s.f. -7,343 s.f)(0.75') = 2,460 c.f. (108%) f/Co Drawdown time- using permeability rates published in the U.S.D. SURVEYFOR DARE COUNTY, NORTH CAROLINA, for Fripp Fine Sands permeability ranges from 6-20 inches per hour. Use low end number for conservative design: 9,270 s.f. basin area x 0.5 ft./hr = 4,635 c.f per hour drawdown time = 11,588 c.f. / 4,635 c.f/hr = 2.5 hours INFILTRATION BASIN "B" Total drainage area = 125,309 s.f. (see basin boundary delineation, plan sheet 5 of 5) Impervious coverage: gravel roadway- 19,136 s.f. parking spaces- 10' x 20' x 27 sites = 5,400 s.f. campers- 8' x 44' x 27 sites = 9,504 s.f. bath house = 864 s.f. TOTAL IMPERVIOUS COVERAGE = 34,904 S.F. (27.9%) Design for 3" rainfall event, calculate unit volume, using Schuler equation- EQ Rv = 0.05 + 0.009(27.9) = 0.30 inches per inch Design volume = 125,309 s.f. x 3"/12 x 0.30 = 9,398 c.f basin capacity: 4' contour area = 7,942 s.f.; 2.5' contour area = 5,5 basin capacity = 5,527 s.f.f.)( (1.5') + (7,942 s.f. - 5,527 s0.75') =j4 0,102 c.f. (108% Drawdown time- using permeability rates published in the U.S.D. ., S. .S., SOIL SURVEY FOR DARE COUNTY, NORTH CAROLINA, for Fripp Fine Sands permeability ranges from 6-20 inches per hour. Use low end number for conservative design: 7,942 s.f. basin area x 0.5 ft./hr = 3,971 c.f. per hour drawdown time = 9,398 c.f. / 3,971 c.f/hr = 2.4 hours PERFORMANCE ENGINEERING 8604 CARATOKE HIGHWAY POWELLS POINT, NC 27966 PHONE 252-491-8354 FAX 252-491-5112 `t0111u1tot" OFE ...... �y 3; 100 i71J1-7l0.6 �.,, ra it W, F IM CAP'N. B's CAMPGROUND — SOILS REPORT ENGINEER'S PROJECT NO.978 JAN 0 3 2007 December 27, 2006 (VA Preface- On site soils investigation and analysis was conducted by the Engineer on December 20, 2006. Borings were augured to a depth of approximately four feet in two locations. The boring locations coincide with the locations of the proposed infiltration basins; Boring A was taken in the location of Basin A and Boring B was taken in the location of Basin B. A review of the U.S.D.A., S.C.S. Soil Survey of Dare County, North Carolina, Sheet number 20 of 22, indicates that the prevailing soil types in the project vicinity are Fripp Fine Sands and Currituck Mucky Peat. The Currituck series soils are located in the adjacent marshy areas lying predominantly to the east and south of the project site. RTi771WR7:Qf1-1101 ►0Ioj"aw.I116W[cIM1 0-6"- light gray sand with thin turf 6"-32"- chocolate brown loamy sand with trace of organics 32"-38"- darker brown loamy sand with slightly more organics FREE WATER IN BORING 36" BELOW SURFACE AFTER TWENTY MINUTES, ELEVATION 0.83' BORING B- GROUND ELEVATION 3.63' 0-6"- light gray sand 6"-18"- medium brown sand with trace organics 18"-36"- dark brown sand with some peat nodules FREE WATER IN BORING 30" BELOW SURFACE AFTER TWENTY MINUTES, ELEVATION 1.13' CAR p 'gyp :oFEssio,�29. SEAL N STP%%lz/zVo --- PERFORMANCE ENGINEERING 8604 CARATOKE HIGHWAY POWELLS POINT, NORTH CAROLINA PHONE 252-491-8354 FAX 252-491-5112 I Permit No. (to provided by DR'Q) State of Nortli Carolina Department, of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM RECER ED1 INFILTRATION BASIN SUPPLEMENT ;if 'i This form may be photocopied for use as an original FEB B 2007 DWO Stormwater Management Plan Review: DWQ-WARO A complete stormwater management plan submittal includes a stormwater management permit application, an infiltration basin supplement for each system, design calculations, soils report and plans and specifications showing all stormwater conveyances and system details. I. PROJECT INFORMATION Project Name: CAr'' W \3` :� C.AN f> QL)\)1AIN> Contact Person: IZnba.(t -S ` A-a,,�al I i W • P ti. Phone Number: (LSZ This worksheet applies to: Basin No. % in Drainage Area _A (as identified on plait) (from Form SWU-101) II. DESIGN INFORMATION - Attach supporting calculations/documentation. The soils report must be based upon an actual field investigation and soil borings. County soil maps are not an acceptable source of soils information. All elevations shall be in feet mean sea level (fmsl). Soils Report Summary Soil Type f Yf op Infiltration -- Infiltration Rate 6 o - 20 d in/hr r cf/hr/sf (circle appropriate units) SHWT Elevation D RJ ' fmsl (Seasonal High Water Table elevation) Basin Design Parameters Design Storm .S inch (1.5 inch event for SA waters, 1 inch event for others) Design Volume i( �7 c.f. Drawdown Time 0. L 1 days Basin Dimensions IRRE(ii,'!)R C£ornEtP Y Basin Size ft. x ft. _ � 34 3 Sq. ft. (bottom dimensions) Basin Volume Provided 1Z�4(nn c.f. Z, J ' (e"J d-'R Basin Elevations Bottom Elevation 7.J ` fmsl Storage Elevation 4, o l fmsl Top Elevation Z finsl Form SWU-103 Rev 3.99 Page I of 3 r, 111. REQUIRED T E-NIS CHECKLIST The following checklist outlines design requirements per the Stornnvater Best Management Practices Manual > - (MC. Department of Environment, Health and Natural Resources, -February 1999) and Administrative Code Section: 15 A NCAC 211 .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 Stornwater 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. r b. System is located at least 100 feet from water supply wells. SFyE 1 i.ARQli71UEc. Bottom of system is at least 2 feel above the seasonal high water table. Al d. Bottom of the system is 3 feet above any bedrock or impervious soil horizon. S e. System is not sited on or in fill material or DWQ approval has been obtained. SEE fJIfekArlU6 f. 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. g. Drainage area for the device is less than 5 acres. h. Soils have a minimum hydraulic conductivity of 0.52 inches per hour and soils report is attached. 'Y i. System captures and infiltrates the runoff from the first 1.0 inch of rainfall (1.5 inch event for areas draining to SA waters ). Design volume and infiltration calculations attached. .f4— s 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. Calculations attached. k� k. All side slopes stabilized with vegetated cover are no steeper than 3:1 (FIN). /JARQIi71U81. A pretreatment device such as a catch basin, grease trap, filter strip, grassed Swale or sediment trap is provided. in. Bottom of the device is covered with a layer of clean sand to an average depth of 4 inches or dense vegetative cover is provided. eF r_ n. Vegetated filter is provided for overflow and detail is shown on plans (Required minimum length is 50 feet for SA waters, 30 feet for other waters). SEr DARPA -ME o. Flow distribution mechanism within the basin is provided. p. A benchmark is provided to determine the sediment accumulation in the pretreatment device. ',EC W-Urluff q. Runoff in excess of the design volume bypasses off-line systems (bypass detail provided). 5 r. System is designed to draw down the design storage volume to the proposed bottom elevation under seasonal high water conditions within five days. A soils report and all pertinent draw -down calculations are attached. U s. Plans ensure that the installed system will meet design specifications (constructed or U restored) upon initial operation once the project is complete and the entire drainage area is stabilized. Form SwU-103 Rev 3.99 Page 2 of 3 IV. INPILTR.ATION I3ASIN OPERATION AND NIAINTENAN'CE AGREEMENT '1.- After every runoff producing rainfall event and at least monthly inspect the infiltration system for erosion, trash -accumulation, vegetative cover, and general condition._- 2. Repair eroded areas immediately, re -seed as necessary to maintain adequate vegetative cover, mow vegetated cover to maintain a maximum height of six inches, and remove trash as needed. After every runoff producing rainfall event and at least monthly inspect the bypass, inflow and overflow structures for blockage and deterioration. Remove any blockage and repair the structure to approved design specifications. Remove accumulated sediment from the pretreatment system and infiltration basin annually or when depth in the pretreatment unit is reduced to 751/o 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 pretreatment unit. The benchmark will document the original design depth so'that accurate sediment accumulation readings can be taken. The measuring device used o 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 design depth reads feet in the pretreatment unit, the sediment shall be removed from both the pretreatment unit and the infiltration basin. If the Division determines that the system is failing, the system will immediately be repaired 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. I acknowledge and agree by my signature below that I am responsible for the performance of the five 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: n I Bcglbn(e 01,046, Address�?��1 Pho C Signature: Note: The legal1), responsible party shou d not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been maned the president. I, Cl2TK1 h ( l� t DG�t l as Notary Public for the State of (J C County of n A 2F , do hereby certify that t`)E1QN ICE - �.1� LLAt2CE personally appeared before me this ,,9Nrj - day of �DPp )if , 006 acknSNIC0111nissionexpires ue execution of the forgoing infiltration basin maintenance requirements. Witness my hand and official sea �t,h? `ii2�c,C �.�pSEAL o0 Form SWU-103 Rev 3.99 Page 3 of 3 Permit No. (to be provided bY DII'p) State of North Carolina Department ofEnvironnient and Natural Resources -- Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM F"ECEIVE® INFILTRATION BASIN SUPPLEMENT FEB 8 2001 This form may be photocopied for use as an original DWQ.WARO DCVO Stormwater Management Plan Review A complete storntwater management plan submittal includes a stormwatcr management permit application, an infiltration basin supplement for each system, design calculations, soils report and plans and specifications showing all stonnwater conveyances and systern details. L PROJECT INFORMATION Project Name: C_AP'N R'S �eMPL��t�t)isD Contact Person: ()b j tar 'S• �� L v> �r t Si Phone Number: (ZS'L. 1 4�1 £i 1 4 This work -sheet applies to: Basin No. (as Uenr;fied on plans) in Drainage Area,_ (from Farm SWU-101) II. DESIGN INFORMATION - Attach supporting calculations/documentation. The soils report must be based upon an actual field investigation and soil borings. County soil maps are not an acceptable source of soils information. All elevations shall be in feet mean sea level (fmsl). Soils Report Summary Soil Type r Y i pp Infiltration Rate (,•o-20,o m/hr ref/hr/sf (circle appropriate an its) SH`rVT Elevation 1 J -�' fmSl 'Seasonal High Water Table elevation) Basin Design Parameters Design Storm Design Volume Drawdown Time Basin Dimensions Basin Size Basin Volume Provided Basin Elevations Bottom Elevation Storage Elevation Top Elevation inch(1.5itneheventforSAwaters, Iincheventforothers) C) c.f. o l days tRREC,v'�.Ak c;Eot.rstTR'( ft. x /o t7L c.f. 2 .S r fmsl 4- fmsl 4.21 fmsl ft. _ _5r��—sq. ft. (bottom dimensions) 2.V Cot1Tc�:2 Form SWU-103 Rev 3.99 Page t of 3 111. lU QUIMA) ITEMS CIlLCKLISI' The follo«ing checklist outlines design requirements per the Stornnvater Best Management Practices Manual (N.C. Department of Environment, Health and Natural Resources, February4-999)-and-Administrative Code Section: 15 A NCAC 211 .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 Storrnwater Management Permit Application Form,- the agent may initial below. Attach justification if a requirement has not been met. Applicants Initials Ns 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. $cC u A kizAh r c. Bottom of system is at least 2 feet above the seasonal high water table. S d. Bottom of the system is 3 feel above any bedrock or impervious soil horizon. e. System is not sited on or in fill material or D%VQ approval has been obtained. 5rELjayaRrruC f. System is located in a recorded drainage casement fertile purposes of opemlion and maintenance and has recorded access easements to the nearest public right-of-way. Q y g. Drainage area for the device is less than 5 acres. f�6c h. Soils have a minimum hydraulic conductivity of 0.52 inches per hour and soils report is attached. i. System captures and infiltrates the runoff from the first 1.0 inch of rainfall (1.5 inch event U for areas draining to SA waters ). Design volume and infiltration calculations attached. 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. Calculations attached. Rcxt _ k. All side slopes stabilized with vegetated cover are no steeper than 3:1 (H:V). ,>C AIaL'f'YFTI& I. A pretreatment device such as a catch basin, grease trap, filter strip, grassed swale or sediment trap is provided. Rt� m. Bottom of the device is covered with a layer of clean sand to an average depth of 4 inches or dense vegetative cover is provided. n. Vegetated filter is provided for overflow and detail is shown on plans (Required minimum U length is 50 feet for SA waters, 30 feet for other waters). ;ir r lihRIZIM J{ o. Flow distribution mechanism within the basin is provided. A benchmark is provided to determine the sediment accumulation in the pretreatment device. q. Runoff in excess of the design volume bypasses off-line systems (bypass detail provided). r. System is designecl to draw down the design storage volume to the proposed bottom elevation under seasonal high water conditions v%ithin five days. A soils report and all pertinent draw-do.vn calculations are attached. s. 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. Form SWU-103 Rev 3.99 Page 2 of 3 IfWIV. IWILTRATION BASIN OPERATION AND MAINTENANCE AGREEMENT 1. After every runoff producing rainfall event and at least monthly inspect the infiltration system for erosion, trash accumulation, vegetative cover, and general condition. -----.--__-_._ 2. Repair eroded areas immediately, re -seed as necessary to maintain adequate vegetative cover, mow vegetated cover to maintain a maximurn height of six inches, and remove trash as needed. 3. After every runoff producing rainfall event and at least monthly inspect the bypass, inflow and overflow structures for blockage and deterioration. Remove any blockage and repair the structure to approved design specifications. 4. Remove accumulated sediment from the pretreatment system and infiltration basin annually or when depth in the pretreatment 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 pretreatment unit. 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 design depth reads feet in the pretreatment unit, the sediment shall be removed from both the pretreatment unit and the infiltration basin. If the Division determines that the system is failing, the system will immediately be repaired to original design specifications. If the system cannot be repaired to perform its design function, other stormwater control devices as allowed by NCAC 21-1 .1000 must be designed, approved and constructed. I acknowledge and agree by my signature below that I am responsible for the performance of the five 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 Nan Address: c Phone: Signature Note Title: RG�_1—qdanev. The legally, responsible parrm shard not be a honteox hers association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. I, R03CRrra �1 �t n �JEt l , a Notary Public for the State of tIN L ' County of I�AfZE ,do hereby certify that 1�)FRiJiOE personally pp rl{t` —,� 1 � �,,,/ Ji . ��4LI—a� Ylei� ersonall appeared before me this a day of I Ih(�QI'1'1 FAQ \' , �4d._l2, and acknow die t e due execution of the forgoin- infiltration basin maintenance requirements. witness my hand and official seal, SEAL MY commission expires C D Form SwU-103 Rev 3.99 Page 3 of 3