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HomeMy WebLinkAboutSW8050527_CURRENT PERMIT_20050615STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW QV�J �Sai DOC TYPE � CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE YYYYMMDD f �QF WArF9p Michael F. Easley, Governor �p G William G. Ross, Jr., Secretary Cl) r North Carolina Department of Environment and Natural Resources fl C Alan W. Klimek, P.E. Director Division of Water Quality June 15, 2005 Mr. Ken Chapman, Member/Manager Plaza East Associates, LLC 125 Scaleybark Road Charlotte, NC 28209 Subject: Stormwater Permit No. SW8 050527 Lumina Commons High Density Project New Hanover County Dear Mr. Chapman: The Wilmington Regional Office received a complete Stormwater Management Permit Application for Lumina Commons on June 10, 2005. Staff review of the plans and specifications has determined that the project, as proposed, will comply with the Stormwater Regulations set forth in Title 15A NCAC 2H.1000. We are forwarding Permit No. SW8 050527 dated June 15, 2005, for the construction of the subject project. This permit shall be effective from the date of issuance until June 15, 2015, and shall be subject to the conditions and limitations as specified therein. Please pay special attention to the Operation and Maintenance requirements in this permit. Failure to establish an adequate system for operation and maintenance of the stormwater management system will result in future compliance problems. If any parts, requirements, or limitations contained in this permit are unacceptable, you have the right to request an adjudicatory hearing upon written request within 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, INC 27611-7447. Unless such demands are made this permit shall be final and binding. If you have any questions, or need additional information concerning this matter, please contact Paul Bartlett, or me at (910) 796-7215, Sin.c rely, Edward Beck ; s Regional Supervisor Surface Water Protection Section ENB/ptb: S:1WQSISTORMWATERIPERMIT1050527 cc: Norris,.Kuske & Tunstall Consulting Engineers, Inc. Tony Roberts, New Hanover County Building Inspections City of Wilmington Stormwater Services Beth E. Wetherill, New Hanover County Engineering Division of Coastal Management Paul T: Bartlett, P.E. Wilmington Regional Office Central Files North Carolina Division of Water Ouality 127 Cardinal Dnve Extension Phone (910) 796-7215 Customer Service 1-877V3-6748 Wilmington Regional Office kNilrningzon, NC 28405-3845 FAX (910) 350-2004 Internet: h2o.enr.state.nc.us One NorthCaroll/ina An EpuaI OpportunitylAffirmative Action Employer— 50%e Recycted110%a Post Consumer Paper Ala turall j/ State Stormwater Management Systems Permit No. SW8 050527 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 Ken Chapman and Plaza East Associates, LLC Lumina Commons New Hanover County FOR THE construction, operation and maintenance of two underground infiltration trenches in compliance with the provisions of 15A NCAC 2H .1000 (hereafter referred to as the "stormwater rules' and the approved stormwater management plans and specifications and other supporting data as attached and on file with and approved by the Division of Water Quality and considered a part of this permit. This permit shall be effective from the date of issuance until June 15, 2015, and shall be subject to the following specified conditions and limitations: I. DESIGN STANDARDS 1. This permit is effective only with respect to the nature and volume of stormwater described`in the application and other supporting data. 2. This stormwater system has been approved for the management of stormwater runoff as described in Section 1.6 on page 3 of this permit. The stormwater control has been designed to handle the runoff from 145,500 square feet of impervious area. 3. The tract will be limited to the amount of built -upon area indicated on page 3 of this permit, and per approved plans. 4. All stormwater collection and treatment systems must be located in either dedicated common areas or recorded easements. The final plats for the project will be recorded showing all such required easements, in accordance with the approved plans. 5. The runoff, from all built -upon area within the permitted drainage area of this project must be directed into the permitted stormwater control system. Page 2 of 7 State Stormwater Management Systems Permit No. SW8 050527 6. The following design criteria have been provided in the infiltration trenches and must be maintained at design conditions: Infiltration Trench System #1 System #2 a. Drainage Area, acres 1.89 1.45 Onsite, ft 82,500 63,000 Offsite, ft None None b. Total Impervious Surfaces, €t 82,500 63,000 c. Design Storm, inches 1.0 1.0 d. Trench Dimensions, L x W x H, ft 90 x 65 x 2 112 x 40 x 2 e. Perforated Pipe Diameter/Length 24"011170' L 24"01896' L f. Bottom Elevation, FMSL 11.0 13.6 Bypass Weir Elevation, FMSL 13.0 15.6 h. Permitted Storage Volume, ft 6,875 5,250 i. Type of Soil ...Silty Sand Silty Sand j. Expected Infiltration Rate, in/hr 0.6 12.8 k. Seasonal High Water Table, FMSL 7.5 11.6 I. Time to Draw Down, hours 23.5 1.1 m. Receiving Stream/River Basin UT to Wrightsville Recreation Area/Cape Fear n. Stream Index Number 18-87-24 o. Classification of Water Body SB# II. SCHEDULE OF COMPLIANCE l 1. The stormwater management system shall be constructed in its entirety, vegetated and operational for its intended use prior to the construction of any built -upon: surface. 2. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately. 3. The permittee shall at all times provide the operation and maintenance necessary to assure the permitted stormwater system functions at optimum efficiency. The approved Operation and Maintenance Plan must be followed in its entirety and maintenance must occur at the scheduled intervals including, but not limited to: a. Semiannual scheduled inspections (every 6 months). b. Sediment removal. C. Mowing and revegetation of slopes and the vegetated filter. d. Immediate repair of eroded areas. e. Maintenance of all slopes in accordance with approved plans and specifications. f. Debris removal and unclogging of bypass structure, filter media, flow spreader, catch basins, piping and vegetated filter. g. A clear access path to the bypass structure must be available at all times. 4. Records of maintenance activities must be kept and made available upon request to authorized personnel of DWQ. The records will indicate the date, activity, name of person performing the work and what actions were taken. 5. The facilities shall be constructed as shown on the approved plans. This permit shall become voidable unless the facilities are constructed in accordance with the conditions of this permit, the approved plans and specifications, and other supporting data. Page 3 of 7 State Stormwater Management Systems Permit No. SW8 050527 6. Upon completion of construction, prior to issuance of a Certificate of Occupancy, and prior to operation of this permitted facility, a certification must be received from an appropriate designer for the system installed certifying that the permitted facility has been installed in accordance with this permit, the approved plans and specifications, and other supporting documentation. Any deviations from the approved plans and specifications must be noted on the Certification. A modification may be required for those deviations. 7. If the stormwater system was used as an Erosion Control device, it must be restored to design condition prior to operation as a stormwater treatment device, and prior to occupancy of the facility. 8. Access to the stormwater facilities shall be maintained via appropriate easements at all times. 9. . The permittee shall submit to the'Director and shall have received approval for revised plans, specifications, and calculations prior to construction, for any modification to the approved plans, including, but not limited to, those listed below: a. Any revision to any item shown on the approved plans, including the stormwater management measures, built -upon area, details, etc. b. Project name change. C. Transfer of ownership. d. Redesign or addition to the approved amount of built -upon area or to the drainage area. e. Further subdivision, acquisition, lease or sale of all or part of the project area. The project area is defined as all property owned by the permittee, for :which Sedimentation and Erosion Control Plan approval or a CAMA Major permit was sought. f. Filling in, altering, or piping of any vegetative conveyance shown on the approved plan. 10. The permittee shall submit final site layout and grading plans for any permitted future areas shown on the approved plans, prior to construction. 11. A copy of the approved plans and specifications shall be maintained on file by the Permittee for a minimum of ten years from the date of the completion of construction. 12. The Director may notify the permittee when the permitted site does not meet one or more of the minimum requirements of the permit. Within the time frame specified in the notice, the permittee shall submit a written time schedule to the Director for modifying the site to meet minimum requirements. The permittee shall provide copies of revised plans and certification in writing to the Director that the changes have been made. III. GENERAL CONDITIONS 1. This permit is not transferable except after notice to and approval by the Director. In the event of a change of ownership, or a name change, the permittee must submit a formal permit transfer request to the Division of Water Quality, accompanied by a completed name/ownership change form, documentation from the parties involved, and other supporting materials as may be appropriate. The approval of this request will be considered on its merits and may or may not be approved. The permittee is responsible for compliance with all permit conditions until such time as the Division approves the transfer request. Page 4of7 State Stormwater Management Systems Permit No. SW8 050527 2. Failure to abide by the conditions and limitations contained in this permit may subject the Permittee to enforcement action by the Division of Water Quality, in accordance with North Carolina General Statute 143-215.6A to 143-215.6C. 3. The issuance of this permit does not preclude the Permittee from complying with any and all statutes, rules, regulations, or ordinances, which may be imposed by other government agencies (local, state, and federal) having jurisdiction. 4. In the event that the facilities fail to perform satisfactorily, including the creation of nuisance conditions, the Permittee shall take immediate corrective action, including those as may be required by this Division, such as the construction of additional or replacement stormwater management systems. 5. The permittee grants DENR Staff permission to enter the property during normal business hours for the purpose of inspecting all components of the permitted stormwater management facility. 6. The permit may be modified, revoked and reissued or terminated for cause. The filing of a request for a permit modification, revocation and reissuance or termination does not stay any permit condition. 7. Unless specified elsewhere, permanent seeding requirements for the stormwater control must follow the guidelines established in the North Carolina Erosion and Sediment Control Planning and Design Manual. 8. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. 9. The permittee shall notify the Division any name, ownership or mailing address changes within 30 days. Permit issued this the 15th day of June 2005. NORTH-CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION zAlan W. Klimek, .E., Director Division of Water Quality By Authority of the Environmental Management Commission Page 5 of 7 State Stormwater Management Systems Permit No. SW8 050527 Lumina Commons Stormwater Permit No. SW8 050527 New Hanover County Designer's Certification I, . , as a duly registered in the State of North Carolina, having been authorized to observe (periodically/ weekly/ full time) the construction of the project, (Project) for (Project Owner) hereby state that, to the best of my abilities, due care and diligence was used in the observation of the project construction such that the construction was observed to be built within substantial compliance and intent of the approved plans and specifications. The checklist of items on page 2 of this form is included in the Certification. Noted deviations from approved plans and specification: Signature Registration Number Date SEAL Page 6 of 7 State Stormwater Management Systems Permit No. SW8 050527 Certification Requirements- 1. The drainage area to the system contains approximately the permitted acreage. 2. The drainage area to the system contains no more than the permitted amount of built -upon area. 3. All the built -upon area associated with the project is graded such that the runoff drains to the system. 4. All roof drains are located such that the runoff is directed into the system. 5. The bypass structure elevations are per the approved plan. 6. The bypass structure is located per the approved plans. 7. A Trash Rack is provided on the outlet/bypass structure. 8. All slopes are grassed with permanent vegetation. 9. Vegetated slopes are no steeper than 3:1. 10. The inlets are located per the approved plans and do not cause short- circ,uiting of the system. 11. The permitted amounts of surface area and/or volume have been provided. 12. All required design depths are provided. 13. All required parts of the system are provided. 14. The required system dimensions are provided per the approved plans. CC' NCDENR-DWQ Regional Office Tony Roberts, New Hanover County Building Inspections Page 7of7 NKT #03113 State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM This form may be photocopied for use as an original I. GENERAL INFORMATION i. Applicants name (specify the name of the corporation, individual, etc. who owns the project): Plaza East Associates, LLC 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Ken Chapman, ( ent I�IiP.. ,W/Nct4Aa^- r 3. Mailing Address for person listed in item 2 above: 125 Scale bark Road City: Charlotte State: NC Zip: 28209 Telephone Number: (704) 561-5238 4. Project Name (subdivision, facility, or establishment name — should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Lumina Commons 5. Location of Project (street address): 1994 Eastwood Road City: Wilmington County: New Hanover 6. Directions to project (from nearest major intersection): Project is located proximately 1/2 mile west of the inters_ ection of US 74 and US 76 bounded by US 74. US 76 and Southerland Avenue 7. Latitude: 340 13' 18" Longitude: 770 49' 18" of project 8. Contact person who can answer questions about the project: Name: J. Phillip Norris, P.E. Telephone Number: 910 343-9653 ll. PERMIT INFORMATION I . Specify whether project is (check one): X New Form SWU-101 Version 3.99 Page 1 of 4 Renewal Modification , • �. '! E ' is . ,E, 2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the Existing permit number NIA And its issue date (if known) NIA 3. Specify the type of project (check one): Low Density High Density X Redevelop General Permit Other 4. Additional Project Requirements (check applicable blanks): CAMA Major X Sedimentation/Erosion Control 404/401 Permit NPDES Stormwater Information on required state permits can be obtained by contacting the Customer Service Center at 1-877-623-6748. III. PROJECT INFORMATION 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. Infiltration Basins 2. Stormwater runoff from this project drains to the Cape Fear River Basin. 3. Total Project Area: 3.34 AC 4. Project Built Upon Area: 100 % 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. i?Basfn Information _,L� ... �. _. Drama eArea;,l d . -. . Drama erArea.,2 _..wi Receiving Stream Name Wrightsville Recreation Area Wrightsville Recreation Area Receiving Stream Class SB SB Drains a Area 82,500 SF 1 1.89 AC 63,000 SF 11.45 AC Existing Impervious * Area To Be Removed To Be Removed Proposed Impervious* Area 82,500 SF / 1.89 AC 63,000 SF 11.45 AC % Impervious* Area total 100% 100% �Im erviousR SurfaceAre""a'�_ _ :. Drama e_Area-1'`: hDraina r — e=Areal �, = .-.. - �: On -site Buildings 15,000 SF 10.34 AC 41,620 SF 10.955 AC On -site Streets 0 0 On -site Parking 63,620 SF 1 1.46 AC 14,949 SF / 0.343 AC On -site Sidewalks 3,880 SF / 0.089 AC 6,431 SF 10.148 AC Other on -site 0 0 Off -site 0 0 Total: 82,500 SF 1 1.89 AC Total: 63,000 SF 11.45 AC " Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas sidewalks, gravel areas, etc. Form SWU-101 Version 3.99 Page 2 of 4 How was the off -site impervious area listed above derived? N/A IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS The following italicized deed restrictions and protective covenants are required to be recorded for all subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table listing each lot number, size and the allowable built -upon area for each lot must be provided as an attachment. The following covenants are intended to ensure ongoing compliance with state stormwater management permit number as issued by the Division of Water Quality. These covenants may not be changed or deleted without the consent of the State. 2. No more than 145,500 squarefeet ofany 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. Swales shall not be filled in, piped, or altered except as necessary to provide driveway crossings. 4. Built -upon area in excess of the permitted amount requires a state stormwater management permit modification prior to construction. A11 permitted runofffrom outparcels or future development shall be directed into the permitted stormwater control system. These connections to the stormwater control system shall be performed in a manner that maintains the integrity and performance of the system as permitted. By your signature below, you certify that the recorded deed restrictions and protective covenants for this project shall include all the applicable items required above, that the covenants will be binding on all parties and persons claiming under them, that they will run with the land, that the required covenants cannot be changed or deleted without concurrence from the State, and that they will be recorded prior to the sale of any lot. V. SUPPLEMENT FORMS The applicable state stormwater management permit supplement form(s) listed below must be submitted for each BMP specified for this project. Contact the Stormwater and General Permits Unit at (919) 733-5083 for the status and availability of these forms. Form SWU-102 Wet Detention Basin Supplement Form SWU-103 Infiltration Basin Supplement Form SWU-104 Low Density Supplement Form SWU-105 Curb Outlet System Supplement Norm SWU-106 Off -Site System Supplement Form SWU-107 Underground Infiltration Trench Supplement Form SWU-108 Neuse River Basin Supplement Form SWU-109 Innovative Best Management Practice Supplement Form SWU-101 Version 3.99 Page 3 of 4 VI. SUBMITTAL REQUIREMENTS Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ). A complete package includes all of the items listed below. The complete application package should be submitted to the appropriate DWQ Regional Office. 1. Please indicate that you have provided the following required information by initialing in the space provided next to each item. • Original and one copy of the Stormwater Management Permit Application Form • One copy of the applicable supplement form(s) for each BMP • Permit application processing fee of $420 (payable to NCDENR) • Detailed narrative description of stormwater treatment / management • Two copies of plans and specifications, including: - Development / Project name -- Engineer and firm - Legend - North arrow - Scale - Revision number & date - Mean high water line - Dimensioned property / project boundary - Location map with named streets or NCSR numbers - Original contours, proposed contours, spot elevations, finished floor elevations - Wetlands delineated, or a note on plans that none exist - Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations - Drainage areas delineated - Vegetated buffers (where required) VII. AGENT AUTHORIZATION If you wish to designate authority to another individual or firm so that they may provide information on your behalf, please complete this section. J. Phillip Norris, P.E. Designated agent (individual or firm): Norris Kuske & Tunsta11 Consulting Engineers, Inc. Mailing Address: City: Wilmin 902 Market Street Phone: (910) 343-9653 State: NC Zip Fax: (910) 343-9604 28401 VII1. APPLICANT'S CERTIFICATION U&,K "Aw &44 1�� 1, (print or type name ofperson listed in General Information, item 2) Ken Chapman, sident , Certify that the information included on this permit application form is, to the best of my knowledge, correct and that the project will be constructed in conformance with the approved plans, that the required deed restrictions and protective covenants will be recorded, and that the proposed project complies with the requirements of 15A NCAC 2H.1000. AFF Signature: Form SWU-101 Version 3.99 Page 4 of 4 Date: 41, 13, fie/ NKT #03113 Permit No.� �j State of North Carolina (to be provided by DWQ) Department of Environment and Natural Resources SGi Fr OSD Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM UNDERGROUND INFILTRATION TRENCH SUPPLEMENT This form may be photocopied for use as an original DWO Stormwater Management Plan Review: A complete stormwater management plan submittal includes a stormwater management permit application, an underground trench supplement for each system, design calculations, and plans and specifications showing all stormwater conveyances and system details. I. PROJECT INFORMATION Project Name: Lumina Commons Contact Person: J. Phillip Norris, P.E. Phone Number: (910) 343-9653 For projects with multiple infiltration systems, a supplement form must be completed for each system. This worksheet applies to: Trench #1 in Drainage Area #1 (from plans) (from Form SWU-101) II. DESIGN INFORMATION (attach supporting calculations/documentation): Soils Report Summary (based upon an actual field investigation and soil borings) Soil Type Silty Sand Infiltration Rate 0.6 Nin/hr or ❑cf/hr/sf (check appropriate units) SHWT Elevation 7.5 fmsl (Seasonal High Water Table elevation) Trench Design Parameters Design Volume 6,875 c.f. Design Storm 1.0 inch event (1.5 inch event far SA waters, 1 inch event for others) Drawdown Time 0.98 days Perforated Pipe Size 24 inch diameter Perforated Pipe Length 1,170 ft. No. Observation Wells 0 (may be required on a case —by-case basis) Stone Type (if used) #57 Stone Void Ratio 0.40 Trench Elevations (in feet mean seal level) Bottom Elevation 11.00 fmsl Storage/Overflow Elevation 13.00 fmsl Form SWU-107 Version 3.99 Pagel of4 .. ,, . �. . E t^ .. `� � F a . � � � r G . �1 � � _ _' � r '� �r c f' :. �. 1 �` ti e � ,.. ' I T � � l .l'. •' 1.' i• .l . i � r . � C... ., o 4 •� � I ,� .' 1 r � i Trench Dimensions Height Width 2.0 ft. Length 90 ft. 65 ft. Volume Provided 6,883 cu.ft. M. REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements per the Stormwater Best Management Practices Manual (N.C. Department of Environment, Health and Natural Resources, February 1999) and Administrative Code Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If the applicant has designated an agent in the Stormwater Management Permit Application form, the agent may initial below. If a requirement has not been met, attach justification. Applicants Initials System is located 50 feet from class SA waters and 30 feet from other surface waters. 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. Off-line system, runoff in excess of the design volume bypasses the system (bypass detail provided). f. System is designed to draw down the design storage volume to the proposed bottom elevation under seasonal high water conditions within five days based upon infiltration through the bottom only (a hydrogeologic evaluation may be required). g. Soils have a minimum hydraulic conductivity of 0.52 inches per hour. h. System is not sited on or in fill material or DWQ approval has been obtained. Plans ensure that the installed system will meet design specifications (constructed or restored) upon initial operation once the project is complete and the entire drainage area is stabilized. J. System is sized to take into account the runoff at the ultimate built -out potential from all surfaces draining to the system, including any off -site drainage. 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. System capture and infiltrates the runoff from the first 1.0 inch of rainfall (1.5 inch event for areas draining to SA waters). Drainage area for the device is less than 5 acres. n. A pretreatment device (filter strip, grassed swale, sediment trap, etc.) is provided. . rench bottom is covered with a layer of clean sand to an average depth of 4 inches. Sides of the infiltration trench are lined with geotextile fabric. q. Rock used is free of fines (washed stone) and has a large void ratio. ode to bottom area ratio is less than 4:1. Form S WU-107 Version 3.99 Page 2 of 4 s. Observation well(s) are provided (case -by -case basis). t. Vegetated filter is provided for overflow (50 feet for SA waters, 30 feet for other waters) and detail is shown on plans. u. A benchmark for checking sediment accumulation is provided. IV. INFILTRATION BASIN OPERATION AND MAINTENANCE AGREEMENT 1. After every runoff producing rainfall event and at least monthly inspect the bypass/overflow structure for blockage and deterioration and the infiltration system for erosion, trash accumulation, grass cover, and general condition. 2. Repair eroded areas immediately, re -seed as necessary to maintain adequate vegetative cover, mow vegetated cover to maintain a maximum height of six -inches, and remove trash as needed. 3. Remove accumulated sediment annually or when depth is reduced to 75% of the original design depth. Restore depth to original design depth without over -excavating. Over -excavating may cause the required water table separation to be reduced and may compromise the ability of the system to perform as designed. 4. The water level in any monitoring wells will be recorded after a I inch rainfall event and at least once a month. Chronic high water table elevations (within 1 foot of the bottom of the system for a period of three months) shall be reported to DWQ immediately. 5. If DWQ determines that the system is failing, the system will immediately be repaired or replaced to original design specifications. If the system cannot be repaired to perform its design function, other stormwater control devices as allowed by NCAC 2H .1000 must be designed, approved and constructed. 6. Remove accumulated sediment from the infiltration system annually or when depth in the unit is reduced to 75% of the original design depth. The system shall be restored to the original design depth without over - excavating. Over excavating may cause the required water table separation to be reduced and may compromise the ability of the system to perform as designed. Removed sediment shall be disposed of in an appropriate manner and shall not be handled in a manner that will adversely impact water quality (i.e. stockpiling near a stormwater treatment device or stream, etc.). A benchmark shall be established in the infiltration system. The benchmark will document the original design depth so that accurate sediment accumulation readings can be taken. The measuring device used to determine the depth at the benchmark shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the depth at the benchmark reads 1.5' , the accumulated sediment shall be removed from the system. Form SWU-107 Version 3.99 Page 3 of .- F:e�vaC �- it -.. .r ��i �� _ _. . 1 ` .�' ' ' 1 � .�]- � r - I acknowledge and agree by my signature below that I am responsible for maintaining the stormwater collection system in accordance with the six maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Print Name and Title: Ken Chapman, Vice-Pr5Sident Address: 125 Scaleybark Road Charlotte, NC 28209 Phone: 704-561-5238 Date: t Signature: J 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, N a No Public for the State of N 6 I1 �kro�'j1� RCounty of Q (- , do hereby certify that taW MCI personally appeared before me this Zday of and acknowledge the due execution of the foregoing infiltration basin maintenance requirements. Witness my hand and official seal. SEAL Signature ion expires L Form S W U-107 Version 3.99 Page 4 of 4 .�� ... ,� ,� • ads e f .- t =� . . M1.ly # • 3 r � � 1 �_ I .d �' � I +..� �ti� 'ti.: � ~ _ ..� ..` ;. • H '} i� l� I . !' N KT #03113 Permit No. _ 03 State of North Carolina (to be provided by DWQ) Department of Environment and Natural Resources S(li 9 0 <b 'L4_ Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM UNDERGROUND INFILTRATION TRENCH SUPPLEMENT This form may be photocopied for use as an original DWQ Stormwater_Managgement Plan Review: A complete stormwater management plan submittal includes a stormwater management permit application, an underground trench supplement for each system, design calculations, and plans and specifications showing all stormwater conveyances and system details. I. PROJECT INFORMATION Project Name Lumina Commons Contact Person: J. Phillip Norris, P.E. Phone Number: (910) 343-9653 For projects with multiple infiltration systems, a supplement form must be completed for each system. This worksheet applies to: Trench #2 in Drainage Area #2 (from plans) (from Form SWU-101) II. DESIGN INFORMATION (attach supporting calculations/documentation): Soils Report Summary (based upon an actual field investigation and soil borings) Soil Type Sand Infiltration Rate 12.8 ®in/hr or [:Icflhr/sf (check appropriate units) SHWT Elevation 11.60 fmsl (Seasonal High Water Table elevation) Trench Design Parameters Design Volume Design Storm Drawdown Time Perforated Pipe Size Perforated Pipe Length No. Observation Wells Stone Type (if used) Stone Void Ratio 5,250 c.f. 1.0 inch event (1.5 inch event for SA waters, 1 inch event for others) 0.046 days 24 inch diameter 896 ft. 0 (may be required on a case —by-case basis) #57 w not Trench Elevations (in feel mean seal level) Bottom Elevation 13.60 fmsl Storage/Overflow Elevation 15.60 fmsl Form SWU-107 Version 3.99 Page 1 of .' � ,• r� � � - - f . , • •� t . � } 7 � 3 r � � � � .. ' ' � � i � .. i ?; � _ Trench Dimensions Height Width 2.0 ft. Length 112 ft. 40 ft. Volume Provided 5,271 cu.ft. M. REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements per the Stormwater Best Management Practices Manual (N.C. Department of Environment, Health and Natural Resources, February 1999) and Administrative Code Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If the applicant has designated an agent in the Stormwater Management Permit Application Form, the agent may initial below. If a requirement has not been met, attach justification. Applicants Initials System is located 50 feet from class SA waters and 30 feet from other surface waters. 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. Off-line system, runoff in excess of the design volume bypasses the system (bypass detail provided). System is designed to draw down the design storage volume to the proposed bottom elevation under seasonal high water conditions within five days based upon infiltration through the bottom only (a hydrogeologic evaluation may be required). g. Soils have a minimum hydraulic conductivity of 0.52 inches per hour. h. System is not sited on or in fill material or DWQ approval has been obtained. i. Plans ensure that the installed system will meet design specifications (constructed or restored) upon initial operation once the project is complete and the entire drainage area is stabilized. j. System is sized to take into account the runoff at the ultimate built -out potential from all surfaces draining to the system, including any off -site drainage. k. System is located in a recorded drainage easement for the purposes of operation and maintenance and has recorded access easements to the nearest public right-of-way. 1. System capture and infiltrates the runoff from the first 1.0 inch of rainfall (1.5 inch event for areas draining to SA waters). M. Drainage area for the device is less than 5 acres. A pretreatment device (filter strip, grassed swale, sediment trap, etc.) is provided. o. Trench bottom is covered with a layer of clean sand to an average depth of 4 inches. Sides of the infiltration trench are lined with geotextile fabric. q. Rock used is free of fines (washed stone) and has a large void ratio. r. de to bottom area ratio is less than 4:1. Form SWU-107 Version 3.99 Page 2 of -S•r � �: � a.. i r f i • _ y _� � _ / ' . 1 •�, .. l � � _ � '� ..i �' 1 + .r� a �{ �r �. i ,.1 ... � - , .� ' .�i. . � e is 'J'_ � .., 1 � f. ''J �-'r L' - _ , .. ._ r+. .. � SS. s. � .* . 'I _ �� �1.4 .. _ � ,. it . r • , ' lit" St 1� r i 'lfl� � _ .. ._ .. .._ .r ., � t� � _.�1' I • !Z�, +.. ,r,. ., .� .. ., t., 1. •'. , .... �;; • 1 .+ �. . 'l, 1. ,. _ ... �. r t , .I .!• .1 � ,i. 'S,� .. � g .1 ' it r J� • ... ' ri i. 1 1 1 r, ' i, I ' �� . . .•t• s. r f' � r. 1 � �! J.r . �Ji �. .. � Y. 1• r + ' s. Observation well(s) are provided (case -by -case basis). t. Vegetated filter is provided for overflow (50 feet for SA waters, 30 feet for other waters) and detail is shown on plans. u. A benchmark for checking sediment accumulation is provided. IV. INFLLTRATION BASIN OPERATION AND MAINTENANCE AGREEMENT i . After every runoff producing rainfall event and at least monthly inspect the bypass/overflow structure for blockage and deterioration and the infiltration system for erosion, trash accumulation, grass cover, and general condition. 2. Repair eroded areas immediately, re -seed as necessary to maintain adequate vegetative cover, mow vegetated cover to maintain a maximum height of six -inches, and remove trash as needed. 3. Remove accumulated sediment annually or when depth is reduced to 75% of the original design depth. Restore depth to original design depth without over -excavating. Over -excavating may cause the required water table separation to be reduced and may compromise the ability of the system to perform as designed. 4. The water level in any monitoring wells will be recorded after a 1 inch rainfall event and at least once a month. Chronic high water table elevations (within 1 foot of the bottom of the system for a period of three months) shall be reported to DWQ immediately. 5. if DWQ determines that the system is failing, the system will immediately be repaired or replaced to original design specifications. If the system cannot be repaired to perform its design function, other stormwater control devices as allowed by NCAC 2H .1000 must be designed, approved and constructed. 6. Remove accumulated sediment from the infiltration system annually or when depth in the unit is reduced to 75% of the original design depth. The system shall be restored to the original design depth without over - excavating. Over excavating may cause the required water table separation to be reduced and may compromise the ability of the system to perform as designed. Removed sediment shall be disposed of in an appropriate manner and shall not be handled in a manner that will adversely impact water quality (i.e. stockpiling near a stormwater treatment device or stream, etc.). A benchmark shall be established in the infiltration system. The benchmark will document the original design depth so that accurate sediment accumulation readings can be taken. The measuring device used to determine the depth at the benchmark shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the depth at the benchmark reads 9 ,50' , the accumulated sediment shall be removed from the system. Form SWU-107 Version 3.99 Page 3 of 4 ��'�"r.' •, r ,.mil; '�-, f � .. .. :� . .. � ,� . ..r r • .. , .._ .., CIS. J� . c. I acknowledge and agree by my signature below that I am responsible for maintaining the stormwater collection system in accordance with the six maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. M'o-, 4111-lY I�a� Print Name and Title: Ken Chapman, V. si ent Address: 125 Soaleybai Phone: 704-561-5238 Signature: Road Charlotte, NC 28209 Date: ell / ZI o / D Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. a Notary Public for the State of a County of do hereby certify that personally appeared before me this Sb '' ^ day of and acknowledge the due execution of the foregoing infiltration basin maintenance requirements. Witness my hand and official seal. My14mmission expires ` O Lbq Form SWU-147 Version 3.99 Page 4 of