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HomeMy WebLinkAboutSW8060704_CURRENT PERMIT_20060721STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW Sn�%1 DOC TYPE � CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE YYYYMMDD o�0 � wA r o -c July 21, 2006 Mr. John A. Psilos, Owner Mr. Perry Kratsa, Owner 106 Cojack Lane Wilmington, NC 28409 Subject: Stormwater Permit No. SW8 060704 Charleston Place High Density Project Onslow County Dear Psilos and Mr. Kratsa: Michael F. Easley, Governor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources Alan W. Klimek, P.E. Director Division of Water Quality The Wilmington Regional Office received a complete Stormwater Management Permit Application for Charleston Place on July 11, 2006 for review on July 18, 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. SW8 060704 dated July 21, 2006, for the construction of the subject project. This permit shall be effective from the date of issuance until July 21, 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 in this permit are unacceptable, you have the right to request an adjudicatory hearing upon written request within sixty (60) days following receipt of this permit. This request must be in the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-7447. Unless such demands are made this permit shall be final and binding. If you have any questions, or need additional information concerning this matter, please contact Paul Bartlett, or me at (910) 796-7215. Sinc Edward Beck Regional Supervisor Surface Water Protection Section ENB/ptb: S:IWQSISTORMWATERIPERMIT1060704 cc: David K. Newsom, P.E., Crystal Coast Engineering, P.A. Mike Morris, Onslow County Building Inspections Paul T. Bartlett, P.E. Wilmington Regional Office' Central Files N"o�` ,Carolina . l Vatrtra!!y North Carolina Division of Water Quality 127 Cardinal Drive Extension Wilmington, NC 28405 Phone (910) 796-7215 Customer Service Wilmington Regional Office Internet: www.ncwaterqualiV.ora Fax (910)350-2004 1-877-623-6748 An Equal Oppoitunity/Affirmative Action Employer — 50% Recycled110%Post Consumer Paper State Stormwater Management Systems Permit No, SW8 060704 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 John A. Psilos and PerryKratsa, Owners Charleston Place Onslow County FOR THE construction, operation and maintenance of two wet detention ponds 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 July 21, 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 in Section 1.6 on page 3 of this permit. The stormwater control has been designed to handle the runoff from 228,897 square feet of impervious area (Pond #1=107,679 sq ft; Pond #2=121,218 sq ft). 3. The tract will be limited to the amount of built -upon area indicated on page 3 of this permit, and per approved plans. The built -upon area for the future development is limited to 18,587 square feet (Drainage Area #1=8,757 sq ft; Drainage Area #2=9,830 sq ft) and is included in the built -upon area totals listed in Section 1.2 of this permit. 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 060704 6. The following design criteria have been provided in the wet detention pond and must be maintained at design conditions: Design Criteria Pond #1 Pond #2 a. Drainage Area, acres: Onsite, ft2 Offsite, ft2 3.33 145,040 None 3.77 164,431 Norte b. Total Impervious Surfaces, ft OS Bldgs, ft2 OS Streets/Prkg, ft2 OS Sidewalks, ft2 OS Other, ft2 OS Future, ft2 107,679 25,236 64,977 8,343 246 8,757 121,218 30,749 68,757 11,162 720 9,830 c. Design Storm, inches 1.0 1.0 d. Pond Depth, ft 7.0 7.0 e. TSS removal efficiency, % 90 90 f. Permanent Pool Elev., FMSI_ 44.5 44.0 g. Perm. Pool Surface Area, ft 4,819 5,275 h. Permitted Storage Volume, ft 8,716 9,924 i. Temporary Storage Elev., FMSL 46.06 45.62 '. Controlling Orifice, "0 pipe 1.25 1.25 k. Permitted Forebay Volume, ft 2,293 2,865 I. Receiving Stream/River Basin UT Northeast Creek! White Oak m.Stream Index Number 19-16-(0.5) n. Classification of Water Body SC; NSW o. Max. horsepower for a fountain 118 1 118 II. SCHEDULE OF COMPLIANCE. 1. The stormwater management system shall be constructed in its entirety, vegetated and operational for its intended use prior to the construction of any built -upon surface. 2. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately. 3. 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 outlet structure, orifice device, flow spreader, catch basins and piping. g. Access to the outlet structure must be available at all times. Page 3 of 7 State Stormwater Management Systems Permit No. SW8 060704 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. Decorative spray fountains will be allowed in the stormwater treatment system, subject to the following criteria: a. The fountain must draw its water from less than 2' below the permanent pool surface. b. Separated units, where the nozzle, pump and intake are connected by tubing, may be used only if they draw water from the surface in the deepest part of the pond. c. The falling water from the fountain must be centered in the pond, away from the shoreline. d. The maximum horsepower for a fountain in either pond is 1/8 horsepower. 6. 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. 7. 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. 8. 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. 9. Access to the stormwater facilities shall be maintained via appropriate easements at all times. 10. 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. 11. The permittee shall submit final site layout and grading plans for any permitted future areas shown on the approved plans, prior to construction. 12. A copy of the approved plans and specifications shall be maintained on file by the Permittee for a minimum of ten years from the date of the completion of construction. Page 4 of 7 State Stormwater Management Systems Permit No. SW8 060704 13. The Director may notify the permittee when the permitted site does not meet one or more of the minimum requirements of the permit. Within the time frame specified in the notice, the permittee shall submit a written time schedule to the Director for modifying the site to meet minimum requirements. The permittee shall provide copies of revised plans and certification in writing to the Director that the changes have been made. III. GENERAL CONDITIONS This permit is not transferable except after notice to and approval by the Director. In the event of a change of ownership, or a name change, the permittee -must submit a formal permit transfer request to the Division of Water Quality, accompanied by a completed name/ownership change form, documentation from the parties involved, and other supporting materials as may be appropriate. The approval of this request will be considered on its merits and may or may not be approved. The permittee is responsible for compliance with all permit conditions until such time as the Division approves the transfer request. 2. Failure to abide by the conditions and limitations contained in this permit may subject the Permittee to enforcement action by the Division of Water Quality, in accordance with North Carolina General Statute 143-215.6A to 143-215.6C. 3. The issuance of this permit does not preclude the Permittee from complying with any and all statutes, rules, regulations, or ordinances, which may be imposed by other government agencies (local, state, and federal) having jurisdiction. 4. In the event that the facilities fail to perform satisfactorily, including the creation of nuisance conditions, the Permittee shall take immediate corrective action, including those as may be required by this Division, such as the construction of additional or replacement stormwater management systems. 5. The permittee grants DENR Staff permission to enter the property during normal business hours for the purpose of inspecting all components of the permitted stormwater management facility. 6. The permit may be modified, revoked and reissued or terminated for cause. The filing of a request for a permit modification, revocation and reissuance or termination does not stay any permit condition. 7. Unless specified elsewhere, permanent seeding requirements for the stormwater control must follow the guidelines established in the North Carolina Erosion and Sediment Control Planning and Design Manual. 8. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. 9. The permittee shall notify the Division any name, ownership or mailing address changes within 30 days. Permit issued this the 21 st day of July 2006. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION _'_ 13 for Alan W. Klimek, P.E., Director Division of Water Quality By Authority of the Environmental Management Commission Page 5 of 7 State Stormwater Management Systems Permit No. SW8 060704 Page 1 of 2 Charleston Place Stormwater Permit No. SW8 060704 Onslow 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 060704 Page 2 of 2 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 outlet/bypass structure elevations are per the approved plan. f. The outlet structure is located per the approved plans. 7. Trash rack is provided on the outlet/bypass structure. 8. All slopes are grassed with permanent vegetation. 9. Vegetated slopes are no steeper than 3:1. 10. The inlets are located per the approved plans and do not cause short- circuiting of the system. 11. The permitted amounts of surface area and/or volume have been provided. 12. Required drawdown devices are correctly sized per the approved plans. .13. All required design depths are provided. 14. All required parts of the system are provided, such as a vegetated shelf, and a forebay. 15. The required system dimensions are provided per the approved plans. M. NCDENR-DWQ Regional Office Mike Morris, Onslow County Building Inspections Page 7 of 7 OFFICE USE ONLY Date Received Feu Paid Permit Number C)7 D(,Zaa& o.00 12 7 1 Sw E P&OZOLf State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERIMIT APPLICATION FORM This form may he phorocopied,/i)r use as an original 1. GENERAL INFOMNIATION 1. Applicants namel(s ecify the name of the corporation, individual, etc. who owns the project): j$perri4 John A. Psilos & gh-my Kratsa 2. Print Owner/Sinning Official's name and title (person legally responsible for facility and compliance): John A. Psilos 3. 1`4aiing Address for person listed in item 2 above: 106 Cojack Lane City: Wilmington State: NC zip:28409 Telephone Number: ( 910 ) 262-8558 4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans, specifications, letters. operation and maintenance agreements, etc.): Charleston Place 5. Location of Project (street address): McDaniel Drive Extension City: Jacksonville County: Onslow 6. Directions to project (froth nearest major intersection): From intersection of US 17 & NC 24 in lacksenville, ourth an US l7 approx. 3.9 miles to Western Blvd. Turn left on Western Blvd & go approx. 0.9 miles & turn right on Gateway South. Go approx 0.3 mi & rum right on Commons Dr. Go approx. 0.3 mi to McDaniel Drive at & turn right. Site approx. 200 ft. on left 7. Latitude: 34 47' 16" N Longitude: 77 23' 39" W 8. Contact person who can answer questions about the project: Name: David K.Newsom Telephone Number: II. PERMIT INFORMATION: 1. Specify whether project is (check one): X New Renewal Forth SWU-101 Version 3,99 Page 1 of i of project 910 1 325-0006 Modification 2'. If this application is being submitted as the result of a renewal or modification to an existing permit, list the existing permit number and its issue date (if known) 3. Specify the type of project (check one): Low Density X High Density Redevelop ... _..... _,__General Permit Other 4. Additional Project Requirements (check applicable blanks): _CAMA Major XSedimentation /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. Ill, PROJECT INFORMATION 1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative (one to two pages) describing stormwater management for the project. Stormwater will be collected and treated in two Wet Detention Basins on site. 2. Stormwater runoff from this project drains to the White Oak 3. Total Project Area: 7.2 acres 5. How many drainage areas does the project have? 2 River basin. 4. Project Built Upon Area: 72.8 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. kBasihslnformattoni1;Drttnage;Aica, Receiving, Stream Name UT of Northeast Creek UT of Northeast Creek Receiving Stream Class SC;NSW SC;NSW Drainage Area 145,040 sf 164,431 sf Existing Impervious* Area 11,357 sf 13,089 sf Proposed lanpervious*Area 96,322 sf 108,129 sf % Impervious* Area (total) 74.2% 73.7% ¢Impervious* S ReArea^ ..� ...>� x 1 i �y airia`ge Are lr : r _ .g r ..: z= . .. » } "; fi� h� Drainage Area 2 ` 3" zM, x• - , :„++a. _ <a,• :tea On -site Buildings (exist/proposed) -0- / 25,356 sf -0-130,749 sf On -site Streets (exist/proposed) 9,624 sf / -0- 10,861 sf / -0- On-site Parking (exist/proposed) -0-155,353 sf -0- / 57,896 sf On -site Sidewalks (exist/proposed) I,733 sf16,610 sf 2,228 sf/ 8,934 sf Other on -site (exist/proposed) -0-1246 sf -0- / 720 sf (Onsite reserve for future) 8,757 sf 9,830 sf 0 W 5ire; = D 8 Total: 107,679 sf (2.47 ac) Total: t21,218 sf (2.78 ac) * fmpervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas, sidewalks, gravel areas, etc. Form S%VU-101 Version 3.99 Page 2 of 4 n�o 7. 1-low was the off -site impervious area listed above derived? 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 Jollowing covenants are intended to ensure ongoing compliance with state stormwater management permit number NIA us issued by the Division of II%ater Quality. These covenants may not be changed or deleted without the consent of the State. 2. ,Vo more than NIA square feet of am 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 ~rood decking or the water surface of,swimming pools. 3..Swales• shall not be filled in, piped, or altered except as necessary to provide driveivay crossings. 4. Built -upon area in excess of the permitted amount requires a state stormwater management permit modification prior to construction. 1. All permitted runoff F•oni outparcels or figure 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 pet formance oj'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. SUPPLUVIENT FORIMS 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 (9I9) 733-5083 for the status and availability of these fonus. Form SWU-102 Wet Detention Basin Supplement Forth SWU-103 Infiltration Basin Supplement Form SWU-104 Low Density Supplement Farm SWU-105 Curb Outlet System Supplement Form SWU-106 Off -Site System Supplement Form SWU-107 Underground Infiltration Trench Supplement Form SWU-108 Meuse River Basin Supplement Form SWU-109 Innovative Best lVlanagement Practice Supplement Form SWU-101 Version 3.99 Page 3 of 4 Vt. SUBNNIITTAL REQUIREMENTS Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ). A complete package includes all of the items listed below. The complete application package should be submitted to the appropriate DWQ Regional Office. Please indicate that you have provided the following required information by initialing in the space provided next to each item. _-4ni tials • Original and one copy of the Stormwater Management Permit Application Form • One copy of the applicable Supplement Form(s) for each BMP a' • Permit application processing fee of $420 (payable to NCDENR) • Detailed narrative description of stormwater treatment/management • Two copies of plans and specifications, including: - Development/Project name - Engineer and firm -Legend - North arrow Scale Revision number & date - Mean high water line - Dimensioned property/project boundary - Location map with named streets or NCSR numbers - Original contours, proposed contours, spot elevations, finished floor elevations - Details of roads, drainage features; collection systems, and stormwater control measures Wetlands delineated; or a note on plans that none exist - Existing drainage (including off -site). drainage easements, pipe sizes, runoff calculations - Drainage areas delineated - Vegetated buffers (where required) VI]. AGENT AUTHORIZATION if you wish to designate authority to another individual or firm so that they may provide information on your behalf, please complete this section. Designated agent (individual or firm): Crystal Coast Engineering, PA ivlailing Address: 3917-3 Freedom Way Citv' Hubert State: NC Zip: 28539 Phone: 1 910 325-0006 Fax: 910 } 325-0060 Vlll. APPLICANT'S CERTIFICATION 1, {print or type name of person fisted in General Information, item ?} VV _ [ ! 1(/� A"r 9 5 certify that the information included on this permit application forth is; to the best of my Icnowledge, correct and that the project will be con acted in conformance with the approved plans, that the required deed restrictions and protective c Ven�,iY be recorf ed, and that the proposed project complies with the requirements of 15A NCAC 21-1.10II Date: c/o -7-aol Form SVU-101 Version 3.99 Page 4 of 4 Permit No. -5w 0&0704 (to be provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORIM VET DETENTION BASIN SUPPLEMENT This form may be photocopied for- use as an original DWO Stormwater Management Plan Review: A complete stormwater management plan submittal includes an application form, a wet detention basin supplement for each basin, design calculations, and plans and specifications showing all basin and outlet structure details. I. PROJECT INFORMATION Proiect Name: Charleston Place Contact Person: David K. Newsom, PE, Crystal Coast Engineering, PA Phone N umber: For projects with multiple basins, specify which basin this worksheet applies to: - elevations Basin Bottom Elevation Permanent Pool Elevation Temporary Pool Elevation areas Permanent Pool Surface Area Drainage Area Impervious Area volumes Permanent Pool Volume Temporary Pool Volume Forebay Volume Other parameters SAIDA i Diameter of Orifice Design Rainfall Design TSS Removal 2 325-0006 1 37.50 ft. (floor of the basin) 44.50 ft. (elevation of the orifice) 46.06 ft. (elevation of the discharge structure overflolti) 4,819 sq. ft. (~eater surface area at the orifice elevation) 3.33 ac, (on -site and oJf-site drainage to the basin) 2.47 ac. (on -site and off=site drainage to the basin) l 1,109 cu. ft. (combined volume of main basin andforebay) 8,716 cu. ft. (volume detained above the permanent pool) 2,293 Cu. ft. (approximately 20% of total volume) 3.112 (surface area to drainage area ratio from DP Q table) 1.23 in. (? to 5 day temporary pool drain -down required) 1" i n. 90 % (minimum 85% required) Fonn SWU-102 Rev 3.99 Page t of 4 Footnotes: I When using the Division SAIDA tables, the con-ect SAIDA ratio for penuanent Pool sizing should be computed based upon the actual impervious % and permanent pool depth. Linear interpolation should be employed to determine the correct value for non- standard table entries. 2 In the 20 coastal counties, the requirement for a vegetative filter may be waived if the wet detention basin is designed to provide 90% TSS removal. The NCDENR 13NIP manual provides design tables for both 851/1, TSS removal and 90% TSS removal. 11. 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 desire requirements have been met and supporting documentation is attached. If the applicant has designated an agent in the Stonnwater Management Permit Application Form, the agent may initial below. If a requirement has not been met, attach justification. Applicants Initials a. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet). b. The forebay volume is approximately equal to 20% of the basin volume. c. The temporary pool controls runoff from the design storm event. d. The temporary pool draws down in 2 to 5 days. e. If required, a 30-foot vegetative filter is provided at the outlet (include non -erosive flow calculations) f. The basin length to width ratio is greater than 3.1. g. The basin side slopes above the permanent pool are no steeper than 3:1. ll. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail). i. Vegetative cover above the permanent pool elevation is specified. j. A trash rack or similar device is provided for both the overflow and orifice. k. A recorded drainage easement is provided for each basin including access to nearest right- of-way. 1. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified prior to use as a wet detention basin. in. A mechanism is specified which will drain the basin for maintenance or an emergency. ,?C,,M1_2 IIl. WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if one is provided. This system (check one) 0 doesoes not incorporate a vegetated filter at the outlet. This system (check one) 0 does Noes not incorporate pretreatment other than a forebay. Form S W U-102 Rev 3.99 Page 2 of 4 Maintenance activities shall be performed as follows: After every significant runoff producing rainfall event and at least monthly: a. Inspect the wet detention basin system for sediment accumulation, erosion, trash accumulation, vegetated cover, and general condition. b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within 2 to 5 days as designed. 2. Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative cover to maintain a maximum height of six inches, and remove trash as needed. 3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to maintain proper functioning. 4. Remove accumulated sediment from the wet detention basin system semi-annually or when depth is reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality (i.e. stockpiling near a wet detention basin or stream, etc.). The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the permanent pool depth reads When the permanent pool depth reads Sediment Removal El, 40.75 Bottom Elevation 39.50 - FOREBAY 75 5.25 feet in the main pond, the sediment shall be removed. 3.75 feet in the forebay, the sediment shall be removed. BASIN DIAGRAM ill in the blanks) Permanent Pool Elevation 44.50 Sediment Removal Elevation 39.25 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Bottom Elevation 37.50 2 5 % MAIN POND 5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These plants shall be encouraged to grow along the vegetated shelf and forebay berm. b. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain shall be minimized to the maximum extent practical. Form SWU-102 Rev 3.99 Page 3 of 4 7. All components of the wet detention basin system shall be maintained in good working order. I acknowledge and agree by my signature below that I am responsible for the performance of the seven maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Print name: John A. Psilos + Py- rry xrQS+AG Title:tl I S Address: 106 Cojack Lane Wilmington, NC 28409 Phon+ Sigm Date: 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 County of New H"ovr-r , do hereby certify that RK!24 Kra so' personally appeared before me this � `" day of , kmt l , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, tAoTARYO ,. UWC; . SEAL My commission expires 3' L - tD Form SWU-102 Rev 3.99 Page 4 of 4 Permit No. 5w S 0;o070q (to be provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORNIWATER MANAGEMENT PERMIT APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form may be photocopied jor use as an original DWQTStormwater Management Plan Review: A complete stormwater management plan submittal includes an application form, a wet detention basin supplement for each basin, design calculations, and plans and specifications showing all basin and outlet structure details. 1. PROJECT INFORMATION Project Name: Charleston Place Contact Person: David K. Newsom PE, Crystal Coast Engineering, PA Phone Number: ( 910 ) 325-0006 For projects with multiple basins, specify which basin this worksheet applies to: 2 elevations Basin Bottom Elevation 37.00 ft. Permanent Pool Elevation 44.00 ft. Temporary Pool Elevation 45.62 fit. areas Permanent Pool Surface Area 5,275 sq. ft, Drainage Area 3.77 ac. Impervious Area volumes 2.78 ac moor of the basin) (elevation of the orifice) (elevation of the discharge structure overf loiv) (water surface area at the orifice elevation) (on -site and off -site drainage to the basin) (on -site and off -site drainage to the basin) Permanent Pool Volume 13,351 cu. ft. (combined volume of main basin andforebay) Temporary Pool Volume 9,924 cu. ft. (volume detained above the permanent pool) Forebay Volume 2,865 cu. ft. (approximately 20% of total volume) Other parameters SAIDA f 3.086 (surface area to drainage area ratio ft•om DTVQ table) Diameter of Orifice 1.25 in. (2 to 5 day temporary pool draw -down required) Design Rainfall 1" Design TSS Removal 2 90 in. % (minimum 85% required) Fonn SWU-102 Rev 3.99 Page I of Footnotes: I when using the Division SA/DA tables, the correct SA/DA ratio for permanent pool sizing should be computed based upon the actual impervious % and permanent pool depth. Linear interpolation should be employed to determine the correct value for non- standard table entries. 2 In the 20 coastal counties, the requirement for a vegetative filter may be waived if the wet detention basin is designed to provide 90% TSS removal. The NCDENR B,MP manual provides design tables for both 85% rsS removal and 90% TSS removal. 11. 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 A 008. 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 M11 a. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet). / b. The forebay volume is approximately equal to 20% of the basin volume. c. The temporary pool controls runoff from the design storm event. Dl Zl d. The temporary pool draws down in 2 to 5 days. e. If required, a 30-foot vegetative filter is provided at the outlet (include non -erosive flow ` calculations) �C/ f. The basin length to width ratio is greater than 3:1. 16g. The basin side slopes above the permanent pool are no steeper than 3:1. ID/6 h. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail). M i. Vegetative cover above the permanent pool elevation is specified. dZ J. A trash rack or similar device is provided for both the overflow and orifice. C'V k. A recorded drainage easement is provided for each basin including access to nearest right- of-way. 1. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified prior to use as a wet detention basin. in. A mechanism is specified which will drain the basin for maintenance or an emergency. ?"ll 111. WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if one is provided. This system (check one) 0 does'�Q es not incorporate a vegetated filter at the outlet. This system (check one) 0 does does not incorporate pretreatment other than a forebay. Form SWU-102 Rev 3.99 Page 2 of Maintenance activities shall be performed as follows: After every significant runoff producing rainfall event and at least monthly: a. Inspect the wet detention basin system for sediment accumulation, erosion, trash accumulation, vegetated cover, and general condition. b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within 2 to 5 days as designed. 2. Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative cover to maintain a maximum height of six inches, and remove trash as needed. 3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to maintain proper functioning. 4. Remove accumulated sediment from the wet detention basin system semi-annually or when depth is reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality (i.e. stockpiling near a wet detention basin or stream; etc.). The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the permanent pool depth reads When the permanent pool depth reads Sediment Removal El. 39.50 5.25 feet in the main pond, the sediment shall be removed. 4.50 feet in the forebay, the sediment shall be removed. BASIN DIAGRAM ill in the hlenkv) Permanent Pool Elevation 44.00 — — — — — -- Sediment Removat Elevation 38 75 73% Bottom Elevation 38.00 % ------------------- — --. Bottum Elevation 37.00 2� FORESAY MAIN POND 5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These plants shall be encouraged to grow along the vegetated shelf and forebay berm. 6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain shall be minimized to the maximum extent practical. Form SWU-102 Rev 3.99 Page 3 of 1. All components of the wet detention basin system shall be maintained in good working order. I acknowledge and agree by my signature below that I am responsible for the performance of the seven maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Print name: John A. Psilos '+— porry Ua- rjg Title: 4 )hq VS Addri Phon, Sign Date: Note: The legally responsible party should riot he 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 -Ayv�kD!N t,-- , a Notary Public for the State of "" 44 G4,04- , County of Pau kxwyee , do hereby certify that ptrrq Kz & personally appeared before me this TL day of joitc Zop(o , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, ,t'r •R`' t4o Y� - rZG'/"z='# SEAL My commission expires 3-2q A Form SWU-102 Rev 3.99 page 4 of 4