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HomeMy WebLinkAboutSW8971225_HISTORICAL FILE_20000131STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW8 cV11125 DOC TYPE ❑ CURRENT PERMIT ❑ APPROVED PLANS ® HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE 2000 o131 YYYYMMDD State of North Carolina Department of Environment and Natural Resources Wilmington Regional Office James B. Hunt, Jr., Governor Bill Holman, Secretary Division of Water Quality Mr. Walter Pancoe, President The Caper Corporation 1901 Kent Street, Suite E Wilmington, NC 28403 Dear Mr. Pancoe: r� NCDENR NORTH rAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES January 31, 2000 Subject: Permit No. SW8 971225 Modification Wrightsville Office Park High Density Stormwater Project New Hanover County The Wilmington Regional Office received a complete modification to the Stormwater Management Permit Application for Wrightsville Office Park on January 31, 2000. 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 971225 Modification dated January 31, 2000, for the construction of Wrightsville Office Park. This permit shall be effective from the date of issuance until January 31, 2010, and shall be subject to the conditions and limitations as specified therein. Please pay special attention to the Operation and Maintenance requirements in this permit. Failure to establish an adequate system for operation and maintenance of the stormwater management system will result in future compliance problems. If any parts, requirements, or limitations contained in this permit are unacceptable, you have the right to request an adjudicatory hearing upon written request within thirty (30) days following receipt of this permit. This request must be in the form of a written petition, conforming to Chapter 150B of the North Carolina General Statutes, and filed with the Office of Administrative Hearings, P.O. Drawer 27447, Raleigh, NC 27611-7447. Unless such demands are made this permit shall be final and binding. If you have any questions, or need additional information concerning this matter, please contact Linda Lewis, or me at (910) 395-3900. Sincerely, Rick Shiver Water Quality Regional Supervisor RSS/arl: S:\WQS\STORMWAT\PERMIT\991225.JAN cc: John Tunstall, P.E. Tony Roberts, New Hanover County Inspections Dave Mayes, P.E., City of Wilmington Beth Easley, New Hanover County Engineering Linda Lewis Wilmington Regional Office Central Files 127 Cardinal Dr. Ext., Wilmington, North Carolina 28405 Telephone 910-395-3900 FAX 910-350-2004 An Equal Opportunity Affirmative Action Employer 50% recycled/10% post -consumer paper State Stormwater Management Systems Permit No. SW8 971225 Modification 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 The Caper Corporation Wrightsville Office Park New Hanover County FOR THE construction, operation and maintenance of a wet detention pond in compliance with the provisions of 15A NCAC 2H A000 (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 January 31, 2010 and shall be subject to the following specified conditions and limitations: I. DESIGN STANDARDS 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 3 of this permit, the Project Data Sheet. The stormwater control has been designed to handle the runoff from 73,636 square feet of impervious area. - 3. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. 4. The tract will be limited to the amount of built -upon area indicated on page 3 of this permit, and per approved plans. State Stormwater Management Systems Permit No. SW8 971225 Modification DIVISION OF WATER QUALITY PROJECT DESIGN DATA SHEET Project Name: Permit Number: Location: Applicant: Mailing Address: Application Date: Name of Receiving Stream/Index #: Classification of Water Body: If Class SA, chloride sampling results: Pond Depth, feet: Permanent Pool Elevation, FMSL: Drainage Area, acres: Total Impervious Surfaces, ft2: Offsite Area entering Pond, ft': Required Surface Area, ft': Provided Surface Area, ft2: Required Storage Volume, ft': Provided Storage Volume, ft': Temporary Storage Elevation, FMSL: Controlling Orifice: Wrightsville Office Park SW8 971225 Modification New Hanover County Mr. Walter Pancoe, President The Caper Corporation 1901 Kent Street, Suite E Wilmington, NC 28403 January 31, 2000 Mineral Springs Branch / (CFR 18-74-63-2-1) "C Sw" n/a 6 20 3.94 73,636 9,160 3,903 4,355 7,770 7,928 21.5 1 " � pipe 3 State Stormwater Management Systems Permit No. SW8 971225 Modification II. SCHEDULE OF COMPLIANCE The stormwater management system shall be constructed in it's entirety, vegetated and operational for its intended use prior to the construction of any built -upon surface except roads. 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 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. g. Access to the outlet 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. Decorative spray fountains will not be allowed in the stormwater treatment system. 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. 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. 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. 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, acquisition, or sale of the project area. The project area is defined as all property owned by the permittee, for which Sedimentation and Erosion Control Plan approval was sought. f. Filling in, altering, or piping of any vegetative conveyance shown on the approved plan. 10. The Director may determine that other revisions to the project should require a modification to the permit. n State Stormwater Management Systems Permit No. SW8 971225 Modification 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. Prior to the sale of any portion of the property, an access/maintenance easement to the stormwater facilities shall be granted in favor of the permittee if access to the stormwater facilities will be restricted by the sale of any portion of the property. 13. The permittee is responsible for verifying that the proposed built -upon area does not exceed the allowable built -upon area. 14. The runoff from all built -upon area on the project must be directed into the permitted stormwater control system. 15. 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. 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. 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) which have 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 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. Permit issued this the 31 st day of January, 2000. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION rl Kerr T. Stevens, Director Division of Water Quality By Authority of the Environmental Management Commission Permit Number SW8 971225 Modification M State Stormwater Management Systems Permit No. SW8 971225 Modification Wrightsville Office Park Stormwater Permit No. SW8 971225 Modification New Hanover County Designer's Certification 1, , as a duly registered in the State of North Carolina, having been authorized to observe (periodically/weekly/full time) the construction of the 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 0 State Stormwater Management Systems Permit No. SW8 971225 Modification 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. The outletibypass structure elevations are per the approved plan. 5. The outlet structure is located per the approved plans. 6. Trash rack is provided on the outlet/bypass structure. 7. All slopes are grassed with permanent vegetation. 8. Vegetated slopes are no steeper than 3:1. 9. The inlets are located per the approved plans and do not cause short-circuiting of the system. 10. The permitted amounts of surface area and/or volume have been provided. 11. Required drawdown devices are correctly sized per the approved plans. 12. All required design depths are provided. 13. All required parts of the system are provided, such as a vegetated shelf, and a forebay, etc 14. The overall dimensions of the system, as shown on the approved plans, are provided. cc: NCDENR-DWQ Regional Office Tony Roberts, New Hanover County Building Inspector A&K1199137 OFFICE USE ONLY Date Received Fee Paid Permit SGvB 9-7/ State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM This form nwy 6e photocopied for use as an original I. GENERAL INFORMATION 1. Applicants name (specify the name of the corporation, individual, etc. who owns the project) The Caper Corporation, General Partner 1900 Ltd. Partnership 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Walter Pancoe. President 3. Mailing Address for person listed in item 2 above: 1901 Kent Street, Suite E City: Wilmington State: NC zip: 28403 Telephone Number: ( 910 1 343-0029 4. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Wrightsvillp Office Park 5. Location of Project (street address): 1900 Dawson Street City: Wilmington County: New Hanover 6. Directions to project (from nearest major intersection): Corner of Wrightsville Avenue and Dawson Street 7. Latitude: 34 IV 30" Longitude: 77a 55' of project 8. Contact person who can answer questions about the project: - Name: Walter Pancoe Telephone Number: ( 910 l 343-0029 H. PERMIT INFORMATION: 1. Specify whether project is (check one): New Renewal % Modification Form SWU-101 Version 3.99 Page 1 of 4 2.4 If this application is being s*WtMnTe result of a renewal or modification to an existing ee?ptg�st the ~ existing permit number and its issue date (if known) 3. Specify the type of project (check one): _Low Density X High Density _Redevelop _General Permit _Other 4. Additional Project Requirements (check applicable blanks): _CAMA Major X Sedimentation/Erosion Control _404/401 Permit _NPDES Stormwater Information on required state permits can be obtained by contacting the Customer Service Center at 1-877-623-6748. III. PROJECT INFORMATION 1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative (one to two pages) describing stormwater management for the project. Wet Detention Pond 2. Stormwater runoff from this project drains to the 3. Total Project Area: 1 _4Q acres 5. How many drainage areas does the project have? Cape Fear River basin. - 4. Project Built Upon Area: 42% % 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. Basm Information ., 3 Drauage Area 1 ��f ' Drainage Area 23 rd EM J y Receiving Stream Name Mineral Springs Branch Receiving Stream Class C—SW Drainage Area Existing Impervious* Area 0.38 ac Proposed Im ervious Area 11,69 %Impervious* Area (total) 42:89% Im ervious" Suiface Area "3;'. d. s"­ - ; Drainage °Area ] wk t t z a ,Dramag6Area 2A=6 -, On -site Buildings 23 800 ft On -site Streets proposed & 35,404 ft On -site Parking exist. On -site Sidewalks 5,272 ft Other on -site Off -site asphalt & walks 19.160 ft2 Total: 73,636 ft =1 ac Total: Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas, sidewalks, gravel areas, etc. Form SWU-101 Version 3.99 Page 2 of 4 7.' How was the off -site impervious area listed above derived? Survey info. & computer IV. DEED RESTRICTIONS AND PROTECTIVE COVENANTS The following italicized deed restrictions and protective covenants are required to be recorded for all subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table listing each lot number, size and the allowable built -upon area for each lot must be provided as an attachment. 1. The following covenants are intended to ensure ongoing compliance with state stormwater management permit number as issued by the Division of Water Quality. These covenants may not be changed or deleted without the consent of the State. 2. No more than square feet of any lot shall be covered by structures or impervious materials. Impervious materials include asphalt, gravel, concrete, brick, stone, slate or similar material but do not include wood decking or the water surface of swimming pools. 3. Swales stall not be filled in, piped, or altered except as necessary to provide driveway crossings. 4. Built -upon area in excess of the permitted amount requires a state stormwater management permit modification prior to construction. 5. All permitted runoff from outparcels or future development shall be directed into the permitted stormwater control system. These connections to the stormwater control system shall be performed in a manner that maintains the integrity and performance of the system as permitted. By your signature below, you certify that the recorded deed restrictions and protective covenants for this project shall include all the applicable items required above, that the covenants will be binding on all parties and persons claiming under them, that they will run with the land, that the required covenants cannot be changed or deleted without concurrence from the State, and that they will be recorded prior to the sale of any lot. V. SUPPLEMENTFORMS The applicable state stormwater management permit supplement form(s) listed below must be submitted for each BMP specified for this project. Contact the Stormwater and General Permits Unit at (919) 733-5083 for the status and availability of these forms. Form SWU-102 Wet Detention Basin Supplement Form SWU-103 Infiltration Basin Supplement Form SWU-104 Low Density Supplement Form SWU-105 Curb Outlet System Supplement Form SWU-106 Off -Site System Supplement Form SWU-107 Underground Infiltration Trench Supplement Form SWU-108 Neuse River Basin Supplement Form SWU-109 Innovative Best Management Practice Supplement Form SWU-101 Version 3.99 Page 3 of 4 -. •.VL 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. I. 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 - Details of roads, drainage features, collection systems, and stormwater control measures - Wetlands delineated, or a note on plans that none exist - Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations - Drainage areas delineated - Vegetated buffers (where required) VII. AGENT AUTHORIZATION If you wish to designate authority to another individual or firm so that they may provide information on your behalf, please complete this section. John S. Tunstall, P. E. Designated agent (individual or firm): Andrew & Kuske Consulting Engineers nc Mailing Address: 902 Market Street City:_ Wilmington State: NC Zip: 28401 Phone:( 910 ) 343-9653 pax: ( 910 1 343-9604 VIII. APPLICANT'S CERTIFICATION I, (print or type name of person listed in General Information, item 2) Walter Pancoe 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. _ Date: �� I Forni SWU-101 Version 3.99 Page 4 of 4 A&Ki199137 Permit No. SCug R71 zZ5 HoO (to be provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form may be photocopied for use as an original DWQ 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 Project Name: _ Wrightsville Office Park Contact Person: Waiter Pancoe Phone Number: ( 910 ) 343-0029 For projects with multiple basins, specify which basin this worksheet applies to: N/A elevations Basin Bottom Elevation Permanent Pool Elevation Temporary Pool Elevation 14 ft. 20 ft. 21.5 (floor of the basin) (elevation of the orifice) ft. (elevation of the discharge structure overflow) areas Permanent Pool Surface Area 4,355 sq. ft. (water surface area at the orifice elevation) Drainage Area 3.94 ac. (on -site and off -site drainage to the basin)' Impervious Area 1.69 ac. (on -site and off -site drainage to the basin) volumes Permanent Pool Volume Temporary Pool Volume Forebay Volume Other parameters SA/DA1 Diameter of Orifice Design Rainfall Design TSS Removal 2 13,095 cu. ft. (combined volume of main basin and forebay) 7,928 cu. ft. (volume detained above the permanent pool) 2,622 cu. ft. (approximately 20% of total volume) 2.4 (surface area to drainage area ratio from DWQ table) 1" in. (2 to 5 day temporary pool draw -down required) 1 in. 90 % (minimum 85% required) Form SWU-102 Rev 3.99 Page 1 of 4 Footnotes: 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. 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 BMP manual provides design tables for both 85% TSS removal and 90% TSS removal. II. 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 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. It . 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. m. A mechanism is specified which will drain the basin formaintenance or an emergency. -Fc p- > Iat.. '�V-1P III. 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 6 does not incorporate a vegetated filter at the outlet. This system (check one) 0 does & does not incorporate pretreatment other than a forebay. Farm SWU-102 Rev 3.99 Page 2 of 4 P'' 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. 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). Remove_ d 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' hgsin or stream, etc.). The measuring device dsed to determi& 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 4.5 feet in the. main pond, the sediment shall be removed. • ' . 0.. When the permanent pool depth reads 3 feet in the forebay, the sediment shall• be removed. BASIN DIAGRAM t (fill in the blanks) Permanent Pool Elevation 2_ Sediment Retkoval El. 17 -------------- \ Sediment Removal Elevation 19.5 75% BottomEle anon--------------------------------------------- ----- Bottom Elevation. 14 25% FOREBAY 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 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: Walter Pancoe •r:.t,,. President Address: 1901 Kent Street, Suite E, Wilmington, NC 28403 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. I, J2r i a CD �� Ma n a Notary Public far the State of '1 orl-lam CCt t-b li n County of J\GAAAan oV tr do hereby certify that WixI '-tr 1'a rt(: O +- personally appeared before me this X� day of I)eC.Zmb•er 1991 and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, fp� �U�dbBa, SEAL My commission expires 7 - ;Co -ADO a - Form S WU-102 Rev 3.99 Page 4 of 4 y W == Andrew & Kuske �pN 31 2000 CONSULTING ENGINEERS, INC. 902 Market St. • Wilmington, North Carolina 28401-4733 • Telephone 910 • ax 910/343- January 27, 2000 Ms. Linda Lewis NCDENR/Div. of Environmental Mgmt. 127 Cardinal Drive Extension Wilmington, NC 28405-3845 RE: Wrightsville Office Park Stormwater Project No. SW8 971225 Modification A & K Project No. 99137 Dear Ms. Lewis: John R. Andrew, P.E. J.A. Kuske, P.E. J. Phillip Norris, P.E. • okengnrs®wllmington.net In reference to your letter of January 25, 2000, we respond as follows: 1. Please find enclosed Sheet C1 with the entire 3.94 acre drainage area highlighted. 2-6. A revised page 2 of 4 of the application and page 1 of 4 of the supplement form is also enclosed. If you have any further questions or comments, please feel free to call. Sincerely, ANDREW & KUSKE CONSULTING ENGINEERS, INC. q4u � Jo n S. Tunstall, P. E. JST/tsm Attachments cc: Mr. Walter Pancoerfhe Caper Corporation (letter) 99137-26 State of North Carolina Department of Environment and Natural Resources Wilmington Regional Office James B. Hunt, Jr., Governor Bill Holman, Secretary Division of Water Quality January 25, 2000 Mr. Walter Pancoe, President The Caper Corporation 1901 Kent Street, Suite E Wilmington, NC 28403 1� NCDENR NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES Subject: ACKNOWLEDGMENT OF RECEIPT AND REQUEST FOR ADDITIONAL INFORMATION Stormwater Project No. SW8 971225 Modification Wrightsville Office Park New Hanover County Dear Mr. Pancoe: The Wilmington Regional Office received a Stormwater Management Permit Application for Wrightsville Office Park on December 15,1999. A preliminary review of that information has determined that the application is not complete. The following information is needed to continue the stormwater review: 1. Please delineate or highlight the entire 3.94 acre drainage area on the plans 2. The temporary pool volume reported on the application is not a cumulative total from the bottom to the storage elevation. It is supposed to be the storage in the pond between the permanent pool and the storage pool. 3. The Design Rainfall on the application is reported as 7". The calculations use 1". Please revise. The total project of 3.49 acres should be reported in Section III, Part 3. The drainage area of 3.94 acres is reported in Section 6. 5. The proposed impervious area in the upper part of Section 6 must include the existing impervious area. The total from the lower part of Section 6 is transferred to the upper portion. 6. The project's BUA percentage is reported as 1.7 acres in Section III, Part 4. Please correct. This percentage is based on the onsite project's built -upon area and site area only and does not include the offsite built -upon or drainage area, ie., 1.48-3.49. 127 Cardinal Dr. Ext., Wilmington, North Carolina 28405 Telephone 910-395-3900 FAX 910-350-2004 An Equal Opportunity Affirmative Action Employer 50% recycled/10% post -consumer paper Mr. Pancoe January 25, 2000 Stormwater Project No. SW8 971225 Modification Please note that this request for additional information is in response to a preliminary review. The requested information should be received by this Office prior to February 25, 2000, or the application Will be returned as incomplete. The return of a project will necessitate resubmittal of all required items, including the application fee. If you need additional time to submit the information, please mail or fax your request for a time extension to the Division at the address and fax number at the bottom of this letter. The request must indicate the date by which you expect to submit the required information. The Division is allowed 90 days from the receipt of a completed application to issue the permit. The construction of any. impervious surfaces, other than a construction entrance under an approved Sedimentation Erosion Control Plan, is a violation ofNCGS 143-215.1 and is subject to enforcement action pursuant to NCGS 143-215.6A.- Please reference the State assigned project number on all correspondence. Any original documents that need to be revised have been sent to the engineer or agent. All original documents must be returned or new originals must be provided. Copies are not acceptable. If you have any questions concerning this matter please feel free to call me at (910) 395-3900. Sincerely`,' — T Linda Lewis Environmental Engineer RSS/arl: S:\WQS\STORMWAT\ADDINFO\971225.JAN cc: Linda Lewis John Tunstall, P.E. 127 Cardinal Dr. Ext., Wilmington, North Carolina 28405 Telephone 910-395-3900 FAX 910-350-2004 An Equal Opportunity Affirmative Action Employer 50% recycled/10% post -consumer paper Andrew & Kuske _ — CONSULTING ENGINEERS, INC. John R. Andrew, P.E. J.A. Kuske, P.E. J. Phillip Norris, P.E. 902 Market St. • Wilmington, North Carolina 28401-4733 • Telephone 910/343-9653 • Fax 910/343-9604 . okengnrs®wilmington.net December 3, 1999 Rr,C1,7,1 EIS NC DENR Division of Water Quality DEC 15 1999 127 Cardinal Drive Extension Wilmington, NC 28405-384 3 3Y: TT 12Z5 MCA Attn: Ms. Linda Lewis RE: Wrightsville Office Park New Hanover County A&K Project No. 99137 Dear Ms. Lewis: RECEIVED DEC 15 1999 ANDREW AND KUSKE Enclosed are two sets of plans for the subject project, two sets of calculations, the original Division of Water Quality stormwater management permit application, two copies of the SWU-102 supplement form, two copies of the stormwater narrative and a $420.00 check for the processing fee. This project was previously permitted under permit #SW8 971225, but due to slight design revisions, we are submitting it for a permit modification. Please review this information for approval and contact us with any questions or comments you may have. Thank you for your assistance on this project. Sincerely, ANDREW & KUSKE CONSULTING ENGINEERS, INC. John S. Tunstall, P. E. JST/tsm Enclosures cc: Mr. Walter Panoce/The Caper Corporation 991376VA STORMWATER MANAGEMENT AND EROSION & SEDIMENTATION CONTROL PLAN WRIGHTSVILLE OFFICE PARK NEW HANOVER COUNTY, NORTH CAROLINA FOR THE CAPER CORPORATION 1901 KENT STREET, SUITE E WILMINGTON, NC 28403 SEAL a I�GjCI 19851 I ' F l NEE ��..._ TUB III) I �" tll 0 R D E C E I V E DEC 151999 D DECEMBER 2, 1999 �7/ZZS 6V PROJ tt PREPARED BY: ANDREW & KUSKE CONSULTING ENGINEERS, INC. 902 MARKET STREET WILMINGTON, NORTH CAROLINA 28401 910/343-9653 910/343-9604 (FAX) A & K #99137 NARRATIVE DESCRIPTION The site is a 3.49 acre tract located on the comer of Wrightsville Avenue and Dawson Street in Wilmington, NC. The site is lightly vegetated with grades ranging from 0% to 5%. Approximately 3.4 acres will be graded to allow construction of an Office Park with paved parking and paved access. The runoff from the site is estimated using the rational method 10 year design storm and rainfall data for the area. Construction is scheduled to begin as soon as all permits and approvals are obtained. The project consists of four new buildings with new parking and access off Colwell Avenue. Approximately 3.4 acres will be disturbed and 1.69 acres (42%) will be covered by impervious surfaces. EROSION CONTROL MEASURES The attached plans and specifications give the requirements for erosion control measures. Silt fencing will be provided along each side of the entrance drive where stormwater would be expected to sheet flow from disturbed areas directly to adjacent property. Gravel check dams will not be provided unless the Contractor has to temporarily discharge into an open ditch instead of the proposed storm drain outfall. The detention pond will be used as a silt basin during construction and restored to its design contours prior to completion. A gravel construction entrance will be constructed at the Colwell Avenue entrance. Maintenance will be provided by the grading contractor and developer. STORMWATER MANAGEMENT MEASURES: The project site is located in New Hanover County. Land disturbing on the site will exceed on acre which requires the site to comply with the City and State Regulations. The stormwater runoff from the development will be directed to the on site stomiwater detention pond. The stormwater detention pond was designed to accommodate this site at 45% Impervious area lot coverage. CONSTRUCTION SEQUENCE The Contractor will install the gravel construction entrance and silt fence prior to beginning any clearing and grading operations. Additional silt fence will be installed when and if conditions warrant during construction. The detention pond/silt basin will be constructed immediately after that portion of the site is cleared, and outlet structure with protection will be installed. Disturbed areas will be landscaped or seeded upon completion. 2 MAINTENANCE PLAN 1. All erosion and sediment control practices will be checked for stability and operation following every runoff -producing rainfall but in no case less than once every week. Any needed repairs will be made immediately to maintain all practices as designed. 2. The sediment basin will be cleaned out when the level of sediment reaches 2.0 ft below the top of the riser. Gravel will be cleaned or replaced when the sediment pool no longer drains properly. 3. Sediment will be removed from the sediment trap and block and gravel inlet protection device when storage capacity has been approximately 50% filled. Gravel will be cleaned or replaced when the sediment pool no longer drains properly. 4. Sediment will be removed from behind the sediment fence when it becomes about 0.5 ft deep at the fence. The sediment fence will be repaired as necessary to maintain a barrier. 5. Check ditches, swales, pond banks, and other seeded areas for erosion and sedimentation after runoff -producing rains. All seeded areas will be fertilized, reseeded as necessary, and mulched according to specifications in the vegetative plan to maintain a vigorous, dense vegetative cover. Sediment producing areas should be treated immediately. 6. Inspect gravel construction roads, entrances, and parking areas periodically for sediment build-up on surface. Topdress with new gravel as needed. 3 SECTION 02920 SOIL EROSION AND SEDIMENTATION CONTROL 1. GENERAL 1.1 Contractor shall take every reasonable precaution throughout construction to prevent the erosion of soil and the sedimentation of streams, lakes, reservoirs, other water impoundments, ground surfaces, or other property as required by State and Local regulations. 1.2 The Contractor shall install all required silt fences, sediment basins, check dams, and construction entrances at the initiation of work, and have these measures reviewed and approved by the local permit authority prior to clearing and grading operations. 1.3 The Contractor shall, within 15 working days or 30 calendar days of suspension or completion of land disturbing activities, provide permanent protective covering for disturbed areas. Temporary and permanent erosion control measures shall be coordinated to assure economical, effective, and continuous erosion and siltation control throughout the construction and post -construction period. Use the specified seed for both temporary and permanent seeding. 2. PRODUCTS 2.1 Asphalt for anchoring mulch shall be Type SS-1 Emulsion. 2.2 Fertilizer shall be 10-10-10 grade or equivalent. 2.3 Lime shall be dolomitic agricultural ground limestone containing not less than 10 percent magnesium oxide. 2.4 Mulch shall be small grain straw, hay, wood chips, asphalt emulsion, jute or other suitable material free of undesirable weed seed. 2.5 Phosphate shall be 20 percent superphosphate or equivalent. 2.6 Seed for temporary and permanent applications shall be 20% carpet grass, 24% Bermuda, 20% turf Fescue, 10% Creeping Red Fescue, and 24% Annual Rye grass. Bermuda seed shall be hulled for warm weather planting and unhulled for cool weather planting. Purity of seed shall be a minimum of 98 percent and germination shall be a minimum of 85 percent n 2.7 Silt fence shall consist of NCDOT Class A fabric supported by wood or metal posts spaced not more than 6 feet on center. The bottom of the fabric shall be buried a minimum of 6 inches. 2.8 Gravel for check dams shall be #57 washed stone. 2.9 Aggregate for construction entrance shall be #4 washed stone. 2.10 Stone rip rap for check dams and erosion control shall be NCDOT Class A or B as shown. 3. EXECUTION 3.1 General: Take every practicable measure during construction or suspension to work to minimize erosion and siltation. Measures should include good construction practices, temporary physical barriers to sediment travel, settling basins for new ditches, and establishment of vegetative cover. 3.2 Construction Practices 3.2.1 Avoid dumping soil or sediment into any wetland or watercourse. 3.2.2 Maintain an undisturbed vegetative buffer where possible between a natural watercourse and trenching and grading operations. 3.2.3 Avoid equipment crossings of streams, creeks, and ditches where practicable. 3.2.4 Grade all cut, fill and ditch slopes to minimum slope of 3:1, unless otherwise shown or directed. 3.3 Temporary Physical Barriers are required where sedimentation on off site property or excessive erosion is a problem. 3.3.1 Mulch shall be used for temporary stabilization of areas subject to excessive erosion and for protection of seed beds after planting where required. 1. Apply grain straw and hay at a rate of 75 to 100 pounds per 1000 square feet and wood chips at a rate of 500 pounds per 1000 square feet. Jute and mesh should be installed as per manufacturer's instructions. 5 2. Asphalt emulsion for slope stabilization should be applied at a rate of 1000 gallons per acre. Asphalt emulsion used for anchoring straw should be applied at a rate of 150 gallons per ton of straw. 3.3.2 Silt Fences shall be used at the base of slopes to restrict movement of sediment from the site. 3.3.3 Stone Check Dams, placed at the discharges of creeks, ditches, and swales, shall consist of Class A rip rap at minimum two feet high and three feet thick across the watercourse, with a one foot thick layer of gravel on upstream side. 3.4 Vegetative Cover: Establish permanent vegetative cover on all unpaved areas disturbed by the work. 3.4.1 Preparation of Seedbed: Areas to be seeded shall be scarified to a depth of 4 inches and until a fine, well pulverized, uniform seedbed is prepared. Lime, phosphorous and fertilizer shall be applied during the scarification process in accordance with the following rates: Lime: 45 pounds per 1000 square feet Phosphorous: 20 pounds per 1000 square feet Fertilizer: 17 pounds per 1000 square feet 3.4.2 Seeding: Disturbed areas shall be seeded with 2 to 3 pounds per 1000 square feet of the specified seed mixture. Seed shall be worked into the bed to a depth of 1/4 inch. 3.4.3 Mulch all areas immediately after seeding. Mulch shall be applied and anchored as specified hereinbefore. 3.5 Construction Entrance: Provide an aggregate drive, 25 feet wide by 50 feet long by 6 inches thick at each entrance to the site used by construction vehicles, until such time as the permanent roadway is constructed. 3.6 Maintenance: The Owner and Contractor shall be responsible for maintaining all temporary and permanent erosion control measures. Temporary structures shall be maintained until such time as vegetation is firmly established in the area protected by the structure. Permanent streambank protection and grassed areas shall be maintained until completion of the project. Areas that fail to show a suitable stand of grass or which are damaged by erosion shall be immediately repaired. END OF SECTION I Date I Design I Andrew and Kuske t�c 902 Market St. CONSULTING ENGINEERS, INC. Wilmington, N.C. 28401t Check Job For Job No. 46/j mvrQ-, � F eiC�no Pre- �, A16 qql,5 I 61��� Cffv D E C E I V E DEC 151999 D I.Date I Design I Andrew and Kuske L�c 902 Market St. CONSULTING ENGINEERS, INC. Wilmington, N.C. 28401 Check Job For Job No. �Tb�7� STIR/2,r�'I�cs�OT��2 C�GC'�(L�✓770N5 GF�,��cy /9� •D�wso n� �r D�XiC� Cc�.���� /ram / - To Tsr Z- /=- 19IZ= 3/74 . TOTAL S/nP��r/OG1S i%�� > /.69A� �`Z,7S!fa,2J>4�� - '7760 %%%l/y7- BAF AaL, y0 S?O.65 %7'70Fi-3 GVD/Z/7+�9L �G � l�God� �6L . �/�i✓/.�i, = 7r1Z��l � �c✓%>. �GI.�i-row_ s�67E!%=i �.�q//v�SE A/G.Cfr = 3• i�dG 2 1�i% f5 = /7ZSCY��ec. I•Date I Design I Andrew and Kuske sheet 902 Market St. CONSULTING ENGINEERS, INC. Wilmington. N.C. 28401 c Check 1,101b For Job No. Del Z,2-4cl,2s) Data for 1900 DAWSON Page 1 TYPE III 24-HOUR RAINFALL= 7.00 IN Prepared by ANDREW & KUSKE CONSULTING ENGINEERS 2 Dec 99 HvdroCAD 5.01 000479 (c) 1986-1998_Aoolied F�icrocomouter Systems_ WATERSHED ROUTING 0 0 a OSUBCATCHMENT REACH Q POND ---�� 1 I LINK SUBCATCHMENT 1 = ENTIRE SITE INCLUDING COLWELL ENTRANCE -> POND 1 REACH 1 = OUTLET PIPE > POND 1 = POND > REACH 1 Data for 1900 DAMSON Page 2 TYPE III 24-HOUR RAINFALL= 7.00 IN Prepared by ANDREW & KUSKE CONSULTING ENGINEERS 2 Dec 99 WvdrnrAn F nl nnna7Q !rl 1QAA-1QQA Annlicd Mirrnrmmmntnr Cvctnmc SUBCATCHMENT 1 ENTIRE SITE INCLUDING COLWELL ENTRANCE PEAK= 16.50 CFS @ 12.10 HRS, VOLUME= 1.06 AF ACRES CN SCS TR-20 METHOD 1.69 98 IMPERVIOUS AREA TYPE III 24-HOUR 2,25 60 LANDSCAPE AREAS/GRASS RAINFALL= 7.00 IN 3.94 76 SPAN= 10-15 HRS, dt=.1 HRS Method Comment Tc (min) DIRECT ENTRY ENTIRE SITE 10.0 Data for 1900 DAWSON TYPE III 24-HOUR RAINFALL= 7.00 IN Preoared by ANDREW & KUSKE CONSULTING ENGINEERS Page 4 2 Dec 99 POND 1 POND Qin = 16.50 CFS @ 12.10 HRS, VOLUME= 1.06 AF Qout= 7.20 CFS @ 12.39 HRS, VOLUME= .85 AF, ATTEN= 56%, LAG= 17.0 MIN ELEVATION AREA INC.STOR CUM.STOR STOR-IND METHOD (FT) (SF) (CF) (CF) PEAK STORAGE = 33125 CF 14.0 10 0 0 PEAK ELEVATION= 23.2 FT 20.0 4355 13095 13095 FLOOD ELEVATION= 24.0 FT 21.0 5600 4978 18073 START ELEVATION= 20.0 FT 21.5 6200 2950 21023 SPAN= 10-15 HRS, dt=.1 HRS 22.0 6890 3273 24295 Tdet= 91.1 MIN (.53 AF) 22.5 7415 3576 27871 23.0 8025 3860 31731 23.5 8685 4178 35909 24.0 9160 4461 40370 # ROUTE INVERT OUTLET DEVICES 1 P 20.0' 1" ORIFICE/GRATE Q=.6 PI r-2 SQR(2g) SQR(H-r) 2 P 21.5' 2.5' x .5' ORIFICE/GRATE Q=.6 Width 2/3 SQR(2g) (H"1.5 [H-Height]"1.5) 3 P 23.2' 16' SHARP -CRESTED RECTANGULAR WEIR Q=C L H"1.5 C=3.27+.4 H/1 L=Length-2(.1 H) Data for 1900 DAMSON Page 3 TYPE III 24-HOUR RAINFALL= 7.00 IN Prepared by ANDREW & KUSKE CONSULTING ENGINEERS 2 Dec 99 HydroCAD 5.01 000479 (cc) 1986-1998 Applied Microcomputer Systems REACH 1 OUTLET PIPE Qin = 7.20 CFS @ 12.39 HRS, VOLUME= .85 AF Qout= 7.19 CFS @ 12.39 HRS, VOLUME= .85 AF, (FT) (SO -FT) (CFS) 0.0 0.0 0.00 .2 .2 .66 .4 .4 2.77 .6 .8 6.20 1.4 2.3 26.52 1.6 2.7 30.96 1.8 3.0 33.75 1.9 3.1 34.07 1.9 3.1 33.75 2.0 3.1 31.67 24" PIPE n= .012 LENGTH= 60 FT SLOPE= .0167 FT/FT ATTEN= 0%, LAG= .1 MIN STOR-IND+TRANS METHOD PEAK DEPTH= .64 FT PEAK VELOCITY= 8.3 FPS TRAVEL TIME _ .1 MIN SPAN= 10-15 HRS, dt=.1 HRS Data for 1900 DAWSON Page 5 TYPE III 24-HOUR RAINFALL= 9.00 IN Prepared by ANDREW & KUSKE CONSULTING ENGINEERS 2 Dec 99 HydroCAD 5.01 000479 (c) 1986-1998 Applied Microcomputer Systems WATERSHED ROUTING 0 J OSUBCATCHMENT REACH Q POND SUBCATCHMENT 1 = ENTIRE SITE INCLUDING COLWELL ENTRANCE REACH I = OUTLET PIPE POND I = POND I I LINK POND 1 > REACH 1 Data for 1900 DAWSON Page 6 TYPE III 24-HOUR RAINFALL= 9.00 IN Prepared by ANDREW & KUSKE CONSULTING ENGINEERS 2 Dec 99 HydroCAD 5.01 000479 (c) 1986-1998 Applied Microcomputer Systems SUBCATCHMENT 1 ENTIRE SITE INCLUDING COLWELL ENTRANCE PEAK= 23.33 CFS @ 12.10 HRS, VOLUME= 1.52 AF ACRES CN SCS TR-20 METHOD 1.69 98 IMPERVIOUS AREA TYPE III 24-HOUR 2.25 60 LANDSCAPE AREAS/GRASS RAINFALL= 9.00 IN 3.94 76 SPAN= 10-15 HRS, dt=.1 HRS Method Comment Tc (min) DIRECT ENTRY ENTIRE SITE 10.0 Data for 1900 DAWSON TYPE III 24-HOUR RAINFALL= 9.00 IN Prepared by ANDREW & KUSKE CONSULTING ENGINEERS Il0IaINI POND Page 8 2 Dec 99 Qin = 23.33 CFS @ 12.10 HRS, VOLUME= 1.52 AF Qout= 19.20 CFS @ 12.22 HRS, VOLUME= 1.29 AF, ATTEN= 18%, LAG= 7.4 MIN ELEVATION AREA INC.STOR CUM.STOR (FT) (SF) (CF) (CF) 14.0 10 0 0 20.0 4355 13095 13095 21.0 5600 4978 18073 21.5 6200 2950 21023 22.0 6890 3273 24295 22.5 7415 3576 27871 23.0 8025 3860 31731 23.5 8685 4178 35909 24.0 9160 4461 40370 # ROUTE INVERT OUTLET DEVICES STOR-IND METHOD PEAK STORAGE = 36243 CF PEAK ELEVATION= 23.5 FT FLOOD ELEVATION= 24.0 FT START ELEVATION= 20.0 FT SPAN= 10-15 HRS, dt=.1 HRS Tdet= 70.8 MIN (.97 AF) 1 P 20.0' 1" ORIFICE/GRATE Q=.6 PI r'2 SQR(2g) SQR(H-r) 2 P 21.5' 2.5' x .5' ORIFICE/GRATE Q=.6 Width 2/3 SQR(2g) (H-1.5 - (H-Height]'1.5) 3 P 23.2' 16' SHARP -CRESTED RECTANGULAR WEIR Q=C L H-1.5 C=3.27+.4 H/1 L=Length-2(.1 H) Data for 1900 DAMSON Page 7 TYPE III 24-HOUR RAINFALL= 9.00 IN Prepared by ANDREW & KUSKE CONSULTING ENGINEERS 2 Dec 99 HYdroCAD 5.01 000479 (c) 1986-1998 Applied Microcomputer Systems REACH 1 OUTLET PIPE Qin = 19.20 CFS @ 12.22 HRS, VOLUME= 1.29 AF Qout= 18.90 CFS @ 12.23 HRS, VOLUME= 1.29 AF, ATTEN= 2%, LAG= .2 MIN DEPTH END AREA DISCH (FT) (SO -FT) (CFS) 0.0 0.0 0.00 .2 .2 .66 .4 .4 2.77 .6 .8 6.20 1.4 2.3 26.52 1.6 2.7 30.96 1.8 3.0 33.75 1.9 3.1 34.07 1.9 3.1 33.75 2.0 3.1 31.67 24" PIPE n= .012 LENGTH= 60 FT SLOPE= .0167 FT/FT STOR-IND+TRANS METHOD PEAK DEPTH= 1.09 FT PEAK VELOCITY= 10.7 FPS TRAVEL TIME _ .1 MIN SPAN= 10-15 HRS, dt=.1 HRS