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HomeMy WebLinkAboutSW7030814_CURRENT PERMIT_20061102STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW DOC TYPE VV CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE DOC DATE YYYYMMDD I • wzx:R b W ArF9Q Michael F. Easley, Governor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources Q Alan W. Klimek, P.E. Director Division of Water Quality DIVISION OF WATER QUALITY November 2, 2006 Dare County Board of Education Attn: Mr. Jim Winebarger PO Box 1508 Nags Head, NC 27959 Subject. Dear Mr. Winebarger: MODIFICATION FOR Stormwater Permit No. SW7030814 Manteo Middle School High Density Stormwater Project Dare County The Washington Regional Office received your request for a permit modification for the subject project on October 3, 2006. Staff review of the plans and specifications has determined that the project, as proposed, will comply with the Stormwater Regulations set forth in Title 15A NCAC 2H.1000. We are forwarding Permit No. SW7030814 dated November 2, 2006 to Dare County Board of Education. This modification replaces the previous permit and shall be effective from the date of issuance. until November 2, 2016 and shall be subject to the conditions and limitations as specified therein. Please pay special attention to the Operation and Maintenance requirements in this permit. Failure to establish an adequate system for operation and maintenance of the stormwater management system will result in future compliance problems. If any parts, requirements, or limitations contained an 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.mus 943 Washington Square Mall Phone: 252-946-6481 Washington, NC 27889 FAX 252-946.9215 An Equal OpportunitylAffirmative Action Employer— 50% Recycled/1 0% Post Consumer Paper Nne orthCarolina Naturally 14 Dare County Board of Education November 2, 2006 Page Two If you have any questions, or need additional information concerning this matter, please contact Mr. Bill Moore at (252)948- 3919. Ancerely, Al Hodge, Regional Supervisor Surface Water Protection Section Washington Regional Office cc: Bissell Professional Group Dare County Planning/Inspections AARO Stormwater Files Central Files State Stormwater Management Systems Permit No. SW7030814 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 Dare County Board of Education 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 vegetated swales and buffers, (1) infiltration basin, and (3) bioretention basins to serve Manteo Middle School located off US64 at Manteo, NC. This modification replaces the previous permit, and shall be effective from the date of issuance until June 16,.2016, and shall be subject to the following specified conditions and limitations: I. DESIGN STANDARDS 1. This permit is effective only with respect to the nature and volume of stormwater described in the application and other supporting data. 2. 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: Manted Middle School sW7030814 Dare County Dare County Board of Education PO Box 640 Manteo, NC 27954 10/03/2006; original 11/01/2006; complete OJT -Roanoke Sound SA 34.06 acres 5.93 acres Basin Required Provided Provided Storage Number Storage Storage Area Elevations_____ Inf #1 3422 cf Bio-Ret ## 5961 cf 1 and IA Bio-Ret #2 4324 cf 33729 cf 11616 sf 12.0 ft 38846 cf 19659 sf 13.0 ft 23234 cf 12818 sf 12.0 ft Bio-Ret #3 2888 cf 23376 cf 6599 sf 12.5 ft 4 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. G. 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. GENERA. 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 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 must request that this permit be renewed. Permit issued this the 2 nd day of November, 2006. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION Alan W. Klimek, P: Director' Division of Water Quality By Authority of the Environmental Management Commission Permit Number SW7030814 7 MODIFICATION FOR Stormwater Permit SW703OB14 (1) Dry Infiltration Basin, (3) Bio-Retention Basins and Vegetated Swales Manteo Middle School Manteo, NC Designer's Certification I, Jr 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 9 I \ tm n I Y,y>1 , I I OFFICE USE ONLY >1`9t tCAr f '.ate ,Aceiye. ea al Permit NumberKim OCT ^ 3 2006 State of North Carolina 5K1ACSC !Q/1tla6 Department of Environment and Natural Resources Division of Water Quality DWQ-►nr , STO ATER MANAGEMENT PERMIT APPLICATION FORM Phis form may he photocopied for use as an original 1. GENERAL INFORMATION 1. Applicants name (specify the name of the corporation, individual; etc. who owns the project): Dare County Board of Education 2, Print Owner/Signing Official's name and tide (person legally responsible for facility and compliance): Jim Winebarger, Director of Maintenance & Construction 3. Mailing Address for person listed in item 2 above: P.O. Box 1508 City Nags Head State NC Zip: 27959 Telephone Number: 252 473-3635 4. Project Name (subdivision, facility, or establishment name -should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Manteo Middle School ' 5. Location of Project (street address): 34 ac. tract of land across from Mother Vineyard Rd. (S.R. 1120) on US Hwy. 64/264 City Manteo County: Dare 6. Directions to project (from nearest major intersection): Adjacent to the intersection of Mother Vineyard Rd. and U.S. Hwy. 64/264 7. Latil 350 54' 00" Longitude: 750 40' 00" of project 3. Contact person who can answer questions about the project: Name: Mr. David Ryan, P.E. Telephone Number: IL PERMIT INE'OWMATION: 1. Specify whether project is (check or New Renewal (252) 261-3266 X Modification Fonn SWU-101 Version 3.99 Page l of 2. If this application is being submitted as a 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 Information on required state permit can be obtained by contacting the Customer Service Center at 1-877-623-6748 III. PROJECT INFORMATION NPDES Stormwater I. 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 runoff from all impervious surfaces will flow overland into a combination of vegetative filters, vegetative buffers, and infiltration basins 2. Stormwater runoff from this project drains to the Pas uotank River Basin 3. Total Project Area: 34.08 acres 4. Project Built Upon Area: 17.40% 5. How many drainage areas does the project have? 8 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 Drainage Area 3 :. . Receiving Stream Name Roanoke Sound Roanoke Sound Roanoke Sound Receiving Stream Class SC SC Sc Drainage Area 3.3 0.48 3.37 ac. Existing Impervious* Area 0 ac. 0 ac. 0 ac. Proposed Impervious* Area 0 ac. 0 ac. 1.64 ac. Impervious* Area (total) 0.00% 0.00% 48.59% Impervious* Surface Area Drainage Area-1 Drainage Area 2 Drainage Area 3. On -Site Buildings 0 0 ac. 18,897 s.f. or 0.43 ac. On -Site Streets 0 0 ac. 2,960 s.f. or 0.07 ac. On -Site Parking 0 0 ac. 36,582 s.f. or 0.84 ac. Other On -Site 0 0 ac. 12,899 s.f. or 0.30 ac. Off -Site 0 0 0 % Impervious* Area (total) 0 • 0 ac. 71,328 sf or 1.64 ac. *Impervious area is defined as the built upon area including, but not limited to, buildings, roacls, parking areas, sidewalks, gravel areas, etc. Forrn SWU-101 Version 3.99 Page 2 of 4 3. Specify the type of project (check one): Low Density High Density Redevelop General Permit Other 4. Additional Project Requirements (check applicable blanks): CAMA Major Sedimentation/Erosion Control 404/401 Permit NPDE, Information on required state permit can be obtained by contacting the Customer Service Center at 1-877-623-6748 111. PROJECT INFORMATION l . 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 runoff from all impervious surfaces will flow overland into a combination of vegetative filters, ve�etative buffers, and infiltration basins 2. Stormwater runoff from this project drains to the Pasquotank River Basin 3. 'Total Project Area: 34.08 acres 4. Project Built Upon Area: 17.40% 5. Flow many drainage areas does the project have'? 8 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 4 .. Drainage:Area5 Drainage AreW , Receiving Strearn Name Roanoke Sound Roanoke Sound Roanoke Sound Receiving Stream Class SC SC SC Drainage Area 1.91 3.01 ac. 7.01 ac. Existing Impervious* Area 0 ac. 0 ac. 0 ac. Proposed Impervious* Area 0.78 ac. 1.09 ac. 0.23 ac. Impervious* Area (total) 40.67% 26.04% 3.28% Impervious* Surface Area Drainage Area 4 Drainage Area 5 .Drainage Area 6 On -Site Buildings 3,522 s.f. or 0.08 ac. 37,524 s.f. or 0.86 ac. 0 On -Site Streets 18,424 s.f. or 0.42 ac. 0 5,659 s.f. or 0.13 ac. On -Site Parking 0 0 0 Other On -Site 11,930 s.f. or 0.27 ac. 9,997 s.f: or 0.23 ac. 4,511 s.f. or 0.10 ac. Off -Site 0 0 0 % Impervious* Area (total) 33,876 s.f. or 0.78 ac. 47,521 s.f. or 1.09 ac. 10,170 s.f. or 0.23 ac. *Impervious area is defr77ed as the built upon area including, bul not limited to, buildings, roads, parking areas, sideivalks, gravel cn•eas, etc. 7. How was the off -site impervious area listed above derived'? N/A 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 Sedimentation/Erosion Control 404/401 Permit NPDE Information on required state permit can be obtained by contacting the Customer Service Center at 1-877-623-6748 III. PROJECT INFORMATION I . 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 runoff from all impervious surfaces will flow overland into a combination of vegetative filters, vegetative buffers, and infiltration basins 2. Stormwater runoff from this project drains to the _ Pasquotank River Basin 3. Total Project Area: 34.08 acres 4. Project Built Upon Area: 17,40% 5. How many drainage areas does the project have? 8 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 7 Drainage Area 8 Receiving Stream Name Roanoke Sound Roanoke Sound Receiving Stream Class SC SC Drainage Area 11.5 ac. 2.34 ac. Existing Impervious* Area 0 ac. 0 ac. Proposed Impervious* Area 1.27 ac. 0.92 ac. Impervious* Area (total) 11,04% 39,24% Impervious* Surface Area ` Drainage Area 4 '"° Drainage•Area 5 " "f On -Site Buildings 8,918 s.f. or 0.20 ac. 0 On -Site Streets 28,425 s.f. or 0.65 ac. 36,050 s.f. or 0.83 ac. On -Site Parking 0 0 Other On -Site 18,052 s.f. or 0.41 ac. 3,920 s.f. or 0.09 ac. Off -Site 0 0 % Impervious* Area (total) 55,395 s.f. or 1.27 ac. 39,970 s.f. or 0.92 ae. *Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas, sidewalks, gravel areas, etc. 7. How was the off -site impervious area listed above derived'? N/A 7. How was the off -site impervious area listed above derived? NIA IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS The following italicized deed restrictoins 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 delted without 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 necessray to provide driveway crossings. 4. Built -upon area in excess of the permitted amount requires a state stormtivater management permit modification prior to construction. S. .411 permitted runoff from outparcels or future development shall be directed into the permitted stormtivater 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 FOPUMS The applicable state stormwater management pennit supplement form(s) listed below must be submitted for each BMP specified for this project, Contact the Stonnwater 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 SVItU-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 Fonn SWU-I01 Version 3.99 Page 3 of Sep 28 06 10:24a Jan DeBlieu (252) 473-1202 W-z/-VH:1/:VO ;ts r L+ oe ... ,rOV f p. 9 VI. SUBMTTAL REQUnUMM Only complete appllcation packages will be accepted and reviewed by the Division of Water Quality (UWQ)L A complete psekage includes all of the items Usted below. The complete application package should be submitted to the appropriate DWQ Regional Office, F lease indicate that you have provided the following required information by initaling in the space provided next to each item. Initials • Original and one copy of the Stormwaur Management Permit Application Form DMR • One copy of the applicable Supplement Fonn(s) for each BMP DMR - Permit application processing fee of $420 (payable to NCDEM) DMR Detailed narrative description of stwmwater ireatmentlaimagement DMR Two copies of plans and specifications, including: NIA - DevelopmentlProject Name - Engineering and firm . legend North . arrow - Scale - Revision number tit date - Mean high Water line . Dimensioned property/project boundary - Location crap with tamed streets or NCSR numbers - Original contours, proposed contours, spot elevations, finished floor elevations - Details of roads, drainage features, collection systems, and stormwater coauol measures - Wetlands delineated, or a note on plans that none exist - Existing drainage (including off -site), drainage easements, pipe sizes, runoff calwlations - Drainage areas delineated - Vegetated buffers (whore reW=d) V11. AGENT ALMMORIZATION If you wish to desginate authority to another individual or firm so that they may provide information on your behalf, please complete this section. 3 Designated agent (individual orffir ): 155miL + eO Mailing Address; -'0, l:'r]ex Ky,t�4_> City M;l- State: NC, Zap Phone: 10 i - 2&1 .52(76 Fax: Vli1 APPLICANT'SCKRTWICATTON 1, (print or type nameofprrson listed in Genem!laformtrtion, item 1) Jim WinebarSer, Director of Maintenance & Constuctron certify that the information included on this permit application form is, to the beat of my knowledge, correct and that the project will be constructed in confottnanra with the approved plans, that the required dcod ruatric(ions and protective covenants will be recorded and that the proposed project complies with the requuirements of 15A NCAC 2H .100 Signature: rw Date: FormSWU-101 Vention3.99 Page4of4 Drainage Basin #4`>,S-M v wATr1L %z,Mi 2VPegzGACt l_. • 9/27/2006 Storinwater Management Calculations Design Storm Event 1.0 in. rainfall event Storm water Management 15A NCAC 211.1005 3(h) Total Drainage Area On -site Drainage Area 1.91 ac. Off -Site Drainage Area 0 ac. Total Drainage Area 1.91 ac. Soils Report Data Soil Type* Baymeade Fine Sand Infiltration Rate* (IR) 6.0 in/hr. Apparent Water Table Elev.** 48 in. *Taken from the Soil Survey Manual, U.S. Dept. of Agriculture **Data taken from On -Site Field Investigation Total # of Drainage Basins Drainage Basin Area #4 83,291 s.f. Drainsee Basin #4 OCT - 3 2006 DWQ-WARD Description Area (FT 2) Factor © Adj. Impervious Area (FT z ) Asphalt Bus Loop 18,424 1.00 18,424 Conc. Sidewalk 9,381 1.00 9,381 Landscaping Stone 2,549 1.00 2,549 Building 3,522 1.00 3,522 Impervious Coverage Total 33,876 Adjusted Impervious Coverage Total 33,876 Total Basin Area (ft 2 ) 83,291 Calculated Impervious Coverage 33,876 Percent Impervious(1) 41 Rv=.05+.009(1) 0.42 Required Pond Volume (ft3) _ (1712")xR „xDA Ix43,560 2,888 t Proposed Pond Storage Depth 2.0 Surface Area Provided @ Pond Bottom (SA bona,,,) 6,599 — Sw f ace Area Provided @ Storage Elevation (SA,,,,,,,,) 20,116 Existing Ground Elevation 12 Proposed Basin Bottom Elevation (TPet,,) 10.50 Proposed Storage Elevation (Se1e1,) 12,50 f Total Storage Volitme Provided (Sfl)Z 26,715 / .Storage Volume Provided Storage Volume Req'd O.K. Ratio of storage volume provided to storage volume required 9.25 Drawdown Calculations Qdrawdown — (SV/SAhol1om)/1R Total Storage Volume Provided Total Basin Bottom Sutface Area (SA In -.Sint Soil Basin Bottom Sun face Area (SA botto„ t ) Soil Infiltration Rate 6.00 in/hr Polling .Soil Basin Bottom .Stuface Area (SA bottom ) Factor of Safety Applied Calculated Potting Soil Basin Bottom Surface Area (SA bottom ) Estitnated Soillnfillration Rate 0.50 in/hr Anticipated Drawdown Period Drawdown Period Drawdown Period is < 5 clays O.K. 0.42 ac. 0.22 ac. 0.06 ac. 0.08 ac. 0.78 ac. 0.78 ac. 1.91 ac. 0.78 ac. ft3 ft. ft2 ft2 ft. rnsl ft. msl ft. msl 0 26,715 ft2 6,599 ft2 6,168 ft' 0.50 ft3/hr/ft' 43 I't2 10 431 ft2 0.0415 W/hr/ftl 105.68 hrs 4.40 days E3sfE��. � `,I a Permit No. to he provided y State of North Carolina Department of Environment and Natural Resources����� Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM OCT - 3 2006 INFILTRATION BASIN SUPPLEMENT DWQ-WARD This form may be photocopied for use as an original DWO Stormwater Manallement Plan Review: 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 : Manteo Middle School Contact Person: Mr, Mark Bissell, P.E. Phone Number: R (252) 261-3266 This worksheet applies to: Basin No. Bio-Ret # 1 A in Drainage Area (as identified on plans) N (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 (finsl). Soils Report Summary Soil Type Baymeade Fine Sand . Infiltration Rate 6.0-20.0 in/hr or cf/hr/sf (circle appropriate units) SHWT Elevation 8.0' frnsl (Seasonal Nigh Water Table elevation) Basin Design Parameters Design Storm 1.0 inch (1.5 inch event for SA waters, 1 inch event for others) Design Volume 5961 c.f. Drawdown Time 4.0 7Z hrs ArPrwvEb FOOfE59t Basin Dimensions Basin Size ft. x Basin Volume Provided 14145 c.f. Basin Elevations Bottom Elevation 11.0 fmsl Storage Elevation 13.0 fmsl Top Elevation 13.0 fmsl Page I of 3 (irregular geometry see attached plan) ft. = sq. ft. (hortom dimensions) Form 5 W U- 103 Rcv.3.99 III. REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements per the Stormwater Best Management Practices Manuz (N.C. Department of Environment, Health and Natural Resources, February 1999) and Administrative Coe Section: 15 A NCAC 2H .1008. Initial in. the space provided to indicate that -the. following design requirements have been met and supportinj documentation is attached. If the applicant has designated an agent in the Stormwater Management Perini Application Form, the agent may initial below. Attach justification if a.requirement has not been met. itials a. System is located 50 feet from class SA waters and 30 feet from other suiface 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. System is not�sited on or in fill material or DWQ approval has,been obtained. L 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. Drainage area for the device is less than 5 acres. Soils have a minimum hydraulic conductivity. of 0.52 inches per hour and soils report is attached. System captures and infiltrates -the runoff from the first 1 0-ffil ch. of}iaiiiifall (1:5 inch event for'areas-draining to SA'waters }. Design,voIii. i and infiltration cai6W$ ons attached. 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. ealcuhwons.atta cheA - All side slopes stabilized with vegetated cover am 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. in. Bottom of the device is covered with a layer of clean sand to an, average depth: of 4 inches go or dense vegetative cover is provided. w4 r*mdS O&L n- Vegetated filter is provided for overflow and detail is shown on plans (Required minimum hv t *-b Tor -LW length is 50 feet for SA waters, 30 feet for other waters). . f'4a41F Pr4U►4Eb .Wj' Flow. distribution mechanism within the basin. is provided. �fivctt ��K3 r aw T1 If. A benchmark is provided to determine the;sediment accumulation in the pretreatment device. (Awm� av�rll�coc✓ , • egy q. Runoff in'excess of the design volume bypasses off-line systems (bypass detail provided). 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. L411A,1,- 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 FJ. INFILTRATION BASIN OPERATION AND MAINTENANCE AGREEMENT l 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 11. S .'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 A 000 must be designed, approved and constructed. I acknowledge and agree by my signature below that I am responsible for the performa9ce 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:, S ? %.)W60 (a 2 /�, Alhw Address: P.O. .2104 (.11(0 ,,,(&)-taO 27� t-1' Phone: _.ZSZL.1j73- 3625 Signature: Date: Z- Z 3- o G Note: The legally responsible party s' ul of 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. l G 1, G jt d� 6t ��U� _ _ _, a Notary Public r the State of V��7� �' h�ounty of do hereby certify that Q fw) ) E-4), personally appeared before me this day of 10 P-U� . and acknowledge the due execution of the forgoing infiltration basin maintenance ` requirements. Witness my hand and official seal, o " OFF4CIAL SEAL" L. I SE �''', ;. Notary Public, North Carolina My commission expires r;ounty of Dare N3ncy W. Marren �• �' M Cor — -scion F-x Tres 4/10l2010 Form e- .9Page 3 of 3 Drainage Basin #3 -0 3T x,,UATM T'VMiT 1.Efi UACA!' Stormwater Management Calculations Design .Storm Event 1.0 in. rainfall event Stornmater Management 15A NCAC 21-L 1005 3(h) Total Drainage Area On -site Drainage Area 3.37 ac. Off -Site Drainage Area 0 ac. Total Drainage Area 3.37 ac. Solis Report Data Soil Type* Baymeade Fine sand Infiltration Rate* (IR) 6.0 in/hr. Apparent Water Table Elev.** 48 in. *Taken from the Soil Survey Manual, U.S. Dept. ofAgriculutre **Data taken from On -Silo Field Investigation Total # of Drainage Basins Drainage Basin Area #3 146,788 s.f. Drainage Basin #3 OCT - 3 2006 DWQ-WARD Description Area (FT ` ) Factor © Adj.linpervious Area (FT z ) Asphalt Parking & Drives 36,582 1.00 36,582 Conc. Sidewalk 10,034 1.00 10,034 10' Asphalt Emergency Access Drive 428 1.00 428 18' Gravel Access Road 2,532 1.00 2,532 Landscaping Stone 2,855 1.00 2,855 Building 18,897 1.00 18,897 impervious coverage totat ia,sets Adjusted Impervious Coverage Total 71,328 Total Basin Area (ft z) 146,788 Calculated Impervious Coverage 71,328 Percent Impervious(l) 49 Rv = .05+ .009(I) 0.49 Required Pond Volume (ft3) = (1"112")xR ,xDA 1x43,560 5,961 Surface Area Provided @ Pond 1 Bottom (SA bonon, ) 14,514 .Surface Area Provided rf Pond 1 Storage Elevation (SA ,, rRRe) 20,778 Proposed Basin I Bottom Elevation (TPe1 v) 11.5 Proposed Basin I Storage Elevation (S ete, )' 13.0 Storage Volume of Basin I Provided (.SV) 26,469 Surface Area Provided @ Pond 1A Bottom (SA 6 ) 5,145 Surface Area Provided @ Pond lA Storage Elevation (SA S,o age) 9,000 Proposed Basin IA Bottom Elevation (TP,,,,) 11.00 Proposed Basin IA Storage Elevation (S e1e) 13.00 Storage Voltune of Basin lA Provided (SV) 14,145 Total Storage Volume Provided (SV) 40,614 SlorageVolume Provided >Slorage Volume Req'd O.K. Ratio of storage volume provided to storage volume required 6.81 Alrrl���� U Ili . *" �V,\I PI:I r] 1 VW 0.84 ac. 0.23 ac. 0.01 ac. 0.06 ac. 0.07 ac. 0.43 ac. 1.64 ac. 1.64 ac. 3.37 ac. 1.64 ac. ft3 €t2 ft2 ft ft ft3 ft2 ft2 ft. ms] ft. mS1 Ft3 0 9/27/2006 Drainage Basin #3 Drawdown Calculations Basin #lA Qdwa d.,, = (SV/SAbortom)11R Total Storage Volume Provided ioral Basin Bottom SlafaceArea (SA bottom) In -Situ .Soil Basin Bottom Sur face Area (.SA battot,r ) Infiltration Rate 6.00 in/hr ,ng Soil Basin Bottom SwfaceArea (SA barro,r, ) actor of Safety Applied alculated Potting Soil Basin Bottom Surface Area (SA bottom) nimated Soil Infiltration Rate 0.50 in/hr ticipated Drawdown Period iwdown Period rwdown Period is < 5 days O.K. 14,145 ft' 5,145 ft' 4,895 I't' 0.50 ft3/hr/ft2 25 ft2 10 250 ft' 0.0415 ft3/hr/ft3 71.77 hrs 2.99 days 9/27/2006 Permit No. (to be provided by DIVO State of North Carolina Department of Environment and Natural Resources Division of Water Quality RECEIVED STORMWATER MANAGEMENT PERMIT APPLICATION FORM INFILTRATION BASIN SUPPLEMENT MAR 1 0 2006 This farm may be photocopied for use as an original DWQ-WARO DWO Stormwater-Manap-ement Plan Review: 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 : Manteo Middle School Contact Person: Mr. Mark Bissell. P.E. This worksheet applies to: Basin No. Inf-Basin#2 (as identified on plans) Phone Number: ((252) 261-3266 in Drainage Area $ (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 Baymeade Fine Sand Infiltration Rate 6.0-20.0 in/hr or cf/hr/sf (circle appropriate units) SHWT Elevation 7.0' fmsl (Seasonal High Water Table elevation) Basin Design Parameters Design Storm 1.0 Design Volutne 3422 inch (1.5 inch event for SA waters, I inch event for others) c. F. Drawdown Time 6.0 hrs. Basin Dimensions Basin Size Basin Volume Provided Basin Elevations Bottom Elevation Storage Elevation Top Elevation (irregular geometry see attached plan) ft. X ft. = sq. ft. (bottom dimensions) 33729 c.f. 9.5 fmsl 12.0 fmsl 12.0 fmsl Page I of 3 Form SWU-103 Rev.3.99 III. 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 109) and Administrative Coe 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 ifa:requirement has not been met. itials a. System is located 50 feet from class SA waters and 30 feet from other surface waters. b. C. d. e. f. System is located at least 100 feet from water supply wells. Bottom of system is at least 2 feet above the.seasonal high.water table: Bottom of the system -is 3 feet above any bedrock or impervious soil horizon. System is not'sited on or in All material or DWQ approval has,been obtained. 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. Drainage area -for the device is less than 5 acres. Soils have a minimum hydraulic conductivity. of 0.52 inches per hour and soils report is attached. System captures and infiltraites the runoff from the first 1.0-inch oi`iai ifall 0 -5 inch event for -areas -draining to SA waters ). -Design'voluirie and infiltrat�oa caIcuIuttions a taehed. 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. ealeulations-attached-. k. All side slopes stabilized with vegetated cover are no -steeper than 3:1 (H:V). 1. 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 awaverage -depth: of 4,inches or dense vegetative cover is provided. Vegetated filter is provided for overflow and detail .is shown on plans (Required minimum m&v t WD To rzrc- length is 50 feet for SA waters, 30 feet for other waters).. fc4024v- Pftu%DEb ,,w r Flow. distribution mechanism within the basin is provided. �fn•ctt KeiM�:3 4fs cw if. A benchmark is provided to determine the; sediment accumulation in the pretreatment device. N� a��rZFiot+✓ , L-g ­Al2C A*W q. Runoff in excess of the design volume bypasses off-line systems (bypass detail provided). 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. I 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 10.12 S . 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 A 000 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: j AlG 5 ifr ,,? Address: l; qC' A!�'d-o Phone: 75 Z; Y"7 3 363 5 Date: Z- 7 3 -O G Signature: Note: The legally responsible parry should.notiie a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. t , a Notary Pub is for the State of ll �� UU1 �.gECounty of 1 , do hereby certify that Q-�- C,)6u U personally appeared before me this day of �5�O�M, and acknowledge the due execution of the forgoing infiltration basin maintenance requirements. Witness my hand and official seal, SE OFFICIALSFft.l_ " ?' ''•b= Notary Public, igOrth Carolina County of f1�Fts t' Na r.y VV Ndwren Fo it3--Rw3°99 My commission expireslLf c� v Page 3 of 3 _.. t� �;� _ _� .:�,.� 1 � S � i Permit No. (to be provided y J State of North Carolina Department of Environment and Natural Resources Division of Water Quality RFmCFmIVE1) STORMWATER MANAGEMENT PERMIT APPLICATION FORM INFILTRATION BASIN SUPPLEMENT MAR 10 2006 This form may be photocopied for use as an original D iyy Q- �YY ARO DWO Stormwater Management Plan Review: A complete stonnwater management plan submittal includes a stonnwater 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. 1. PROJECT INFORMATION Project Name : Manteo Middle School Contact Person: Mr. Mark Bissell. P.E. This worksheet applies to: Basin No, Inf-Basin#1 (as identified on plans) Phone Number: t (252) 261-3266 in Drainage Area 4 (from Form SWU-101) 11. 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 Baymeade Fine Sand Infiltration Rate 6.0-20.0 in/hr or cflhrlsf (circle appropriate units) SI-IWT Elevation 8.0' fmsl (Seasonal High Water Tahle elevation) Basin Design Parameters Design Storm 1.0 Design Volume 2888 Drawdown Time 8.0 Basin Dimensions Basin Size Basin Volume Provided Basin Elevations Bottom Elevation Storage Elevation Top Elevation inch (1.5 inch event far SA waters, 1 inch event for others) c.f. hrs (irregular geometry see attached plan) ft. x ft. = sq. ft. (bottom dimensions) 26715 c.f. 10.5 fmsl 12.5 fmsl 12.5 fmsl Page 1 of 3 Form SWU-103 Rev.3.99 III. 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 Coc, 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. ltials 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. d. e. f. Bottom of system is at least 2 feet above the. seasonal high, water table: Bottom of the system is 3 feet above any bedrock or impervious soil horizon. System is not sited on or in fill material or DWQ approval hasbeen obtained. 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. Drainage area -for the device is less than 5 acres. Soils have a minimum hydraulic conductivity.of 0.52 inches per hour and soils report is attached. System captures and infiltrates the runoff from the first 1.0'inch.ofiaiii fall (1.5..inch event forareas draining to SA�waters ). Design volume and infiltration calculations attached. 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. Calculationsattached. k_ All side slopes stabilized with vegetated cover am no -steeper than 3:1 (H:V). 1. A pretreatment device such as a catch basin, grease trap, filter strip, grassed Swale or sediment trap is provided. 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. &-9 rtiKdS j?,W a n. Vegetated filter is provided for overflow and detail .is shown on plans (Required minimum �ruv t4tk� ra r� length is 50 feet for SA waters, 30 feet for other waters).. tr+�� wrwv�Ofb . Flow. distribution mechanism within the basin.is provided. �3� rtlf A benchmark is provided to determine the sediment accumulation in the pretreatment device. AN w►e?�Z�cvr✓ , e6u q. Runoff in excess of the design volume bypasses off-line systems (bypass detail provided). T. 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. 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. INFII.TRATION BASIN OPERATION AND MAINTENANCE AGREEMENT P 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 11.Sj* - 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: A!&C %> f7 . 01A)E g1`KZj�C V1 Z A- 2 -�r X10 Address: ?.U. qyaX Gqo :!!Itt-A1AID _r_. ZZ yS-'r Phone: Z! Z- u 7 3' 3 (, 3 5 Date: Z- Z!2 -G jr, _ Signature: 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. 1 a Not Public for the State of C"'��Coun of aryry do hereby certify that ?.A79-1)QXG �A— personally appeared before me this�_� day of, and acknowledge the due execution of the forgoing infiltration basin maintenance requirements. Witness my hand and official seal, S ,r... • OFFICIAL - SEAL " My commission expires l L7 >-6 f Notary R;bHC, Norlh Carolina f con;. ty of Dare F Nar,(�v W. Warren F -t corReKa99xpires411012010 Page 3 of 3 - 4f - I Pennit No. (to be provided by DI VQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality RECEIVE STORMWATER MANAGEMENT PERMIT APPLICATION FORM ��ss INFILTRATION BASIN SUPPLEMENT MAR 1 0 2006 This form may be photocopied for use as an original DWQ_WARO DWQ Stormwater Management Plan Review: II 9 �/ 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 : Manteo Middle School Contact Person: Mr. Mark Bissell, P.E. Phone Number: 1(252) 261-3266 This worksheet applies to: Basin No. Bio-Ret # 1 A in Drainage Area 3 (as identified on plans) (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 Baymeade Fine Sand Infiltration Rate 6.0-20.0 in/hr or cf/hr/sf (circle appropriate units) SHWT Elevation $,0' fmSl (Seasonal Nigh Water Table elevation) Basin Design Parameters Design Storm 1.0 Design Volume 5961 Drawdown Time 4.0 Basin Dimensions Basin Size ft. x Basin Volume Provided 14145 Basin Elevations Bottom Elevation 11.0 Storage Elevation 13.0 Top Elevation 13.0 inch (1.5 inch event for SA raters, I inch evens for others) c. f. hrs c. f. fmsl fmsl frost Page I of 3 Form S W U- i 03 Rev3.99 (irregular geometry see attached plan) ft. = sq. ft. (bottont dimensions) III. 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 Coe 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. tials 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. System is not sited on or in fill material or DWQ approval has been obtained. 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. Drainage area for the device is less than 5 acres. Soils have a minimum by �nlic conductivity. of 0.52 inches per hour and soils report is attached. System captures and infiltrates the runoff from the first Iftinch.orai dfall (1,S inch event for -areas draining to.SA waters ). Design, Vblume and infiltration calculations attached. 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. All side slopes stabilized with vegetated cover. are no -steeper than 3:1 (H:V). 1. 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 -depthof 4,inches or dense vegetative cover is provided. &-q omaS ON n. Vegetated filter is provided for overflow and detail .is shown on plans (Required minimum mav ► oez ra rttg- length is 50 feet for SA waters, 30 feet for other waters). . Flow. distribution mechanism within the basin.is provided. �fNcc{- .k�Mics nar L 4n ew s1*. A benchmark is provided to determine the%sediment accumulation in the pretreatment device. Aw ov�it�iov-�, (.-q , Zcw o a. Runoff in excess of the design volume bypasses off-line systems (bypass detail provided). 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. 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 I %, 'T . 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. 1 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: 5 _ 2 �,.)I--J4r /64A.) l 6 crr 7"F, Address: Plc?• _? X BYO A;.)-1L 0 AAC 2 7� Z -7 " 3G 7 r Date: Z- Z3 -oG Signature: Note: The legally responsible party shoul"ot be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. I, (A-) a Notary Public f r the State of /�o��GC `-�t_-,!�County of do hereby certify that , ��f'tQ/J Lo personally appeared before me this day of .IO and acknowledge the due execution of the forgoing infiltration basin maintenance requirements. Witness my hand and official seal, OrFICIAL SEAL" L r jQ 1 7� 5E Notary Pt,b,fc, North Caroiina My commission expires [ U �f,; County of Dare t{ Nan ,y W Warren •• M Comm ;;ion Ex Tres 4/10/2010 Fo v`3.� Page 3 of 3 t• Permit No. to he provided y State of North Carolina Department of Environment and Natural Resources RECEIVED Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM MAR 1 0 2006 INFILTRATION BASIN SUPPLEMENT This form may be photocopied for use as an original D v Q"WARO DWQ Stormwater Management Plan Review: 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 : Manteo Middle School Contact Person: Mr. Mark Bissell, P.E. This worksheet applies to: Basin No. Bio-Ret 4 1 (as identified on plans) Phone Number: I (252) 261-3266 in Drainage Area 3 (from Fowl 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 Baymeade Fine Sand Infiltration Rate 6.0-20.0 in/hr or cf/hr/sf (circle appropriate units) SL-LWT Elevation 8.0' fmSl (Seasonal High Water Table elevation) Basin Design Parameters Design Storm 1.0 Design Volume 5961 Drawdown Time 4.0 Basin Dimensions Basin Size Basin Volume Provided Basin Elevations Bottom Elevation Storage Elevation Top Elevation inch (1.5 inch event for SA waters, 1 inch event for others) c. f. hrs (irregular geometry sec attached plan) ft. x ft. = sq. ft. (bottom eliniensions) 26469 c.f. 11.5 fmsl 13.0 fmsl 13.0 fmsl Page 1 of 3 Form S W U-103 Rev.3.99 III. 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 Coe 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. tials 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. System is not sited on or in fill material or DWQ approval has been obtained. 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. Drainage area for the device is less than 5 acres. 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. ofrairifall (I..5 inch event for areas draining to.SA waters ). Design volume and inftltion 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. C.alculations-attached. k. All side slopes stabilized with vegetated cover. are no steeper than 3:1 (H: V). 1. A pretreatment device such as a catch basin, grease trap, filter strip, grassed swale or sediment trap is provided. m. Bottom of the device is covered with a layer of clean sand to an average j depth, of 4 inches or dense vegetative cover is provided. 6.9rn,K91.Qwo n. Vegetated filter is provided for overflow and detail is shown on plans (Required minimum rrav t tab To r%W length is 50 feet for SA waters, 30 feet for other waters). Flow_ distribution mechanism within the basin is provided_ Rf-&C MtKS oav ► twz o,4 vi if. A benchmark is provided to deter -nine the,sediment accumulation in the pretreatment device. I�w o,��rlPio�✓ . - egy >q. Runoff in excess of the design volume bypasses off-line systems (bypass detail provided). 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 s. pertinent draw -down calculations are attached. 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. Form SWU-103 Rev 3.99 Page 2 of 3 i .. � � �� �• ' ' i 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 11.87 I . 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: Address: _� 4 >30 �cy ?'yl Lc) Al C _ L 2 Phone: ; `� 3 — 3 t" 3� Date: Z - z 1�7- Gv Signature: Note: The legally responsible party ihould'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. 1, , a Notary Public r the State of ounry of do hereby certify that naLz) personally appeared before me this day of , adb and acknowledge the due execution of the forgoing infiltration basin maintenance requirements. Witness my hand and official seal, "OFFICIAL SEAL' Notary Public. North Carolina Na- -'y' kN. WEIF�-er, M•�`. AA CofT1n!;��pnkxri�t3547?Ol2a10 My commission expires_ L 1 b 1 Page 3 of 3 Permit No. to he provide y State of North Carolina Department of Environment and Natural Resources Division of Water Quality RECED STORMWATER MANAGEMENT PERMIT APPLICATION FORM INFILTRATION BASIN SUPPLEMENT MAR 10 2006 This form may be photocopied for rise rrs an original `n� ry DWO Stormwater Manap-ement Plan Review: ��ArYY ~o _Yy~�� 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. PR03ECT INFORMATION Project Name : Manteo Middle School Contact Person: Mr. Mark Bissell, P.E. This worksheet applies to: Basin No. Bio-Ret # 2 (as identified on plans) Phone Number: ((252) 261-3266 in Drainage Area 5 (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 learia loamy fine sand Infiltration Rate 0.6-2.0 in/hr or cf/lir/sf (circle appropriate units) SN WT Elevation 8.0' fmsl (Seasonal High Water Table elevation) Basin Design Parameters Design Storm 1.0 Design Volume 4324 Drawdown Time 11.0 Basin Dimensions Basin Size ft. x Basin Volume Provided 23234 Basin Elevations Bottom Elevation 10.5 Storage Elevation 12.0 Top Elevation 12.0 inch (1.5 inch event for SA waters, I inch event for others) c. f. hrs c.f. fmsl fmsl fmsl Page I of 3 Fonn SWU-103 Rev.3.99 (irregular geometry sce attached plan) ft. = Sq. ft. (bottom dimensions) i III. 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 Coe 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. itials a. System is located 50 feet from class SA waters and 30 feet from other surface waters. b. C. d. e. f. System is located at -least 100 feet from water supply wells. Bottom of system is at least 2 feet above the. se, high• water table: Bottom of the system is 3 feet above any bedrock or impervious soil horizon. System is not'sited on or in fill material or DWQ approval has been obtained. 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. Drainage area -for the device is less than 5 acres. Soils have a minimum hydraulic conductivity. of 0.52 inches per hour and soils report is attached. System captures and infiltrates the runoff from the first 1.0"iach o irai`rifall (1.S inch event for -areas -draining to SA'waters ). Design volume wind infiltration calculations attached. 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. All side slopes stabilized with vegetated cover. are no steeper than 3:1 (H:V). 1. A pretreatment device such as a catch basin, grease trap, filter strip, grassed swale or sediment trap is provided. 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. r.-`!rr'yXS RkUb n. Vegetated filter is provided for overflow and detail.is shown on plans (Required minimum �r"v, t-b To 'r %W length is 50 feet for SA waters, 30 feet for other waters).. f4+tflor pmv t� :r Flow distribution mechanism within the basin.is provided. Rf.-C* #k-Ntrs onw►wb a,4 if. A benchmark is provided to determine the -sediment accumulation in the pretreatment device. Ah� ov�rjPtaa✓ . - , - ;ft q. Runoff in excess of the design volume bypasses off-line systems (bypass detail provided). 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. 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%v 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. If When the design depth reads 1 ,b7S_ . 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: _,� h .L 5 ?Z . Ld),&k Address:v 4:2 . GOIZ (.-'4 ,vl,� �'IG-_U •✓G _ _L 74 i Phone: 2 • `'f 7 3- 3 3 5 Date: _-2 - Z,5 — UCH Signature: Note: The legally responsible party not 6e 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- � 4, County of do hereby certify that a rlcu L personally appeared before me this Pl day of and acknowledge the due execution of the forgoing infiltration basin maintenance requirements. Witness my hand and official seal, SE "rl �� "OFFICIAL SEAS • My commission expires t a 5 Notary Public. North Carolina � %€f ' el''!I'y of Dare W, Warren -•�' M-Cornri�:s,oEx ires411o12010 Form - nPage 3 of 3