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Home My WebLink AboutSW8880910_CURRENT PERMIT_20210913STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW8 $$00I l0 DOC TYPE] CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE 102\ 0�►3 YYYYMMDD ROY COOPER covemw ELIZABETH S BISER Secretary BRIAN WRENN olrector September 13, 2021 IKA Works, Inc Atm Rene Sttegelmann, President 2635 Northchase Pkwy SE Wilmington, NC 28405 NORTH CAROLINA Environmental Quality Subject Permit Renewal State Stormwater Management Permit No SW8 880910 H{A Works North America Expansion and Renovation New Hanover County Dear Ms Stiegelmann The Wilmington Regional Office received a complete 8 year Stormwater Management Permit Renewal Application for the subject project on August 23, 2021 The Division is hereby notifying you that permit SW8 880910 has been renewed on September 13, 2021, and shall be effective until January 25, 2028 For your records, please find enclosed a renewed updated, and re -issued permit and a copy of the renewal application As requested, a copy of the current operation and maintenance agreement is enclosed Please keep this permit on file at all times Please note that the renewed, updated, and re -issued perms does not impose new or different terms, it merely restates some of the previous terms to provide you with a better understanding of your obligations under the permit The renewal and reissuance of this stormwater permit does not imply that the site is currently in compliance with the terms and conditions of this state stormwater permit The plans originally approved on September 26, 1988 and most recently modified on January 15, 2016, will remain in full force and effect in accordance with the regulations set forth in Title 15A NCAC 2H 1000 This permit is subject to the conditions and limitations as specified therein Please pay special attention to the conditions listed in this permit regarding the Operation and Maintenance of the BMP(s), recordation of deed restrictions, procedures for changes of ownership, transferring the permit, and renewing the permit Failure to establish an adequate system for operation and maintenance of the stormwater management system, to record deed restrictions, to transfer the permit, or to renew the permit, 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 by filing a written petition with the Office of Administrative Hearings (OAH) The written petition must conform to Chapter 150B of the North Carolina General Statutes, and must be filed with the OAH within thirty (30) days of receipt of this permit You should contact the OAH with all questions regarding the filing fee (if a filing fee is required) and/or the details of the filing process at 6714 Mail Service Center, Raleigh, NC 27699-6714, or via telephone at 919-431-3000, or visit their website at www NCOAH com Unless such demands are made this permit shall be final and binding If you have any questions, need additional copies of the permit or approved plans, please contact Ashley Smith in the Wilmington Regional Office, at (910) 796-7215 or ashleym smith@ncdenr gov Sincerely, aLa' rw � Brian Wrenn, Director Division of Energy, Mineral and Land Resources Enclosures O & M Agreement Attachment C — Permitting History Renewal Application Documents DES/ams \\\Stormwater\Permits & Projects\l 988\8809 10 HDQ021 09 perms 8809I0 cc NCDEQ-DEMLR Wilmington Regional Office �R North Carolina Department of Environmental Quality I Division of Energy Mineral and Land Resources J/ 5I2 North Salisbury Street 11612 Mail Service Center I Raleigh North Carolina 27699-1612 ws,m v mr.,waiwu.so...w w.w� y 9197079200 State Stormwater Management Systems Permit No SW8 880910 STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENTAL QUALITY DIVISION OF ENERGY, MINERAL AND LAND RESOURCES 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 IKA Works, Inc IKA Works North American Expansion and Renovation 2635 Northchase Pkwy SE, Wilmington, New Hanover County FOR THE construction, operation and maintenance of one (1) wet detention pond in compliance with the provisions of 15A NCAC 2H 1000 and Session Law 2008-211, as applicable (hereafter collectively referred to as the "stormwater rules') the approved stormwater management plans and specifications and other supporting data as attached and on file with and approved by the Division of Energy, Mineral and Land Resources (the "Division" or "DEMLR") and considered an enforceable part of this permit This permit shall be effective from the date of issuance until January 25, 2028, 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 18 of this permit The runoff from all built -upon area within the permitted drainage area of this project must be directed into the permitted stormwater control system The stormwater control has been designed to handle the runoff from 344,541 square feet of impervious area 3 The maximum built -upon area allowed for the entire project is 344,541 square feet The drainage area will be limited to the amount of built -upon area indicated in Sections 12 and 1 8 of this permit, and per approved plans This permit does not provide any allocation of built - upon area for future development A 50' wide vegetative buffer must be provided and maintained adjacent surface waters, measured horizontally from and perpendicular to the normal pool of impounded structures, the top of bank of both sides of streams and rivers and the mean high water line of tidal waters A vegetated filter strip is not required for this pond as it has been designed for a 90% total suspended solids removal efficiency Page 1 of 5 State Stormwater Management Systems Permit No SW8 880910 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 Access to the stormwater facilities for inspection and maintenance shall be maintained via appropriate recorded easements at all times The following design criteria have been permitted for the wet detention pond and it must be provided and maintained at the design condition a Drainage Area, acres Onsite, subject to 15A NCAC 2H 1000, Onsite, subject to SL 2008-211, ft2 Offsite, subject to 15A NCAC 2H 1000, Offsite, subject to SL 2008-211, ft2 b Total Impervious Surfaces, ft2 Onsite, subject to 15A NCAC 2H 1000, Onsite, subject to SL 2008-211, ft2 Offsite, subject to 15A NCAC 2H 1000, Offsite, subject to SL 2008-211, ft2 c Design Storm 15A NCAC 2H 1000, inches SL 2008-211, inches d Pond Design Depth, feet e TSS removal efficiency f Permanent Pool Elevation, FMSL g Permanent Pool Surface Area, ft2 h Temporary Storage Volume, ft' i Temporary Storage Elevation, FMSL t Controlling Orifice k Orifice flowrate, cfs I Permanent Pool Volume, ft' m Permitted Forebay Volume, ft' n Fountain Horsepower o Receiving Stream/River Basin p Stream Index Number q Classification of Water Body II SCHEDULE OF COMPLIANCE 1608 ft2 186,214 178.605 ft2 235,834 99,906 344,541 ft2 99,207 116,436 ft2 78,945 49.953 10 15 30 90% 3000 40,537 35,637 3080 3 0" 0 pipe 11 86,863 17,252 1/3 Smith Creek / Cape Fear 18-74-63 " C, Sw" 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 During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately 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 The permittee shall at all times provide the operation and maintenance necessary to assure that all components of the permitted stormwater system function at design condition The approved Operation and Maintenance Agreement is incorporated by reference into this permit and must be followed in its entirety and maintenance must occur at the scheduled intervals Records of maintenance activities must be kept and made available upon request to authorized personnel of Division The records will indicate the date, activity, name of person performing the work and what actions were taken Page 2 of 5 State Stormwater Management Systems Permit No SW8 880910 5 Decorative spray fountains are allowed in the pond, subject to the following criteria a The minimum permanent pool volume is 30,000 cubic feet b The fountain must draw its water from less than 2' below the permanent pool surface c 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 d The fountain may not be placed into the forebay e The falling water from the fountain must be centered in the main pond, away from the shoreline f The maximum horsepower for a fountain in this pond is 1/3 horsepower 6 The facilities shall be constructed, operated and maintained in accordance with the provisions of this permit, the approved plans and specifications, and the supporting documents attached to this permit and on file with the Division 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 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 9 Prior to transfer of the permit, a file review and site inspection will be conducted by Division personnel to ensure the permit conditions have been met and that the protect and the on -site stormwater system complies with the permit conditions Any items not in compliance must be repaired, replaced restored, or resolved prior to the transfer Records of maintenance activities performed to date may be requested 10 No person or entity, including the permittee, shall alter any component shown in the approved plans and specifications Prior to the construction of any modification to the approved plans, the permittee shall submit to the Director, and shall have received approval for modified plans, specifications, and calculations including, but not limited to, those listed below For changes to the protect or SCM that impact the certifications, a new or updated certification(s), as applicable, will be required and a copy must be submitted to the appropriate DEQ regional office upon completion of the modification a Any modification to the approved plans and specifications, regardless of size including the SCM(s), BUA, details, etc b Redesign or addition to the approved amount of BUA or to the drainage area c Further development, subdivision, acquisition, lease or sale of any, all or part of the protect and/or property area as reported in the approved plans and specifications d Altering, modifying, removing, relocating, redirecting, regrading, or resizing of any component of the approved SCM(s), the stormwater collection system and/or vegetative conveyance shown on the approved plan e The construction of any allocated future BUA f The construction of any permeable pavement, #57 stone area, public trails, or landscaping material to be considered a permeable surface that were not included in the approved plans and specifications g Other modifications as determined by the Director III GENERAL CONDITIONS Any individual or entity found to be in noncompliance with the provisions of a stormwater management permit or the requirements of the stormwater rules is subject to enforcement procedures as set forth in NCGS 143 Article 21 Page 3 of 5 State Stormwater Management Systems Permit No SW8 880910 The issuance of this permit does not preclude the permittee from complying with and obtaining any other permits or approvals that are required for this development to take place, as required by any statutes, rules, regulations, or ordinances, which may be imposed by any other Local, State or Federal government agency having jurisdiction Any activities undertaken at this site that cause a water quality violation or undertaken prior to receipt of the necessary permits or approvals to do so are considered violations of NCGS 143-215 1, and subject to enforcement procedures pursuant to NCGS 143-215 6 3 If the facilities fail to perform satisfactorily, the permittee shall take immediate corrective actions This includes actions required by this Division and the stormwater rules such as the construction of additional or replacement on -site stormwater systems These additional or replacement measures shall receive a permit from the Division prior to construction 4 Permit Transfer This permit is not transferable to any person or entity except after notice to and approval by the Director The permittee shall submit a completed and signed "Permit Transfer Application Form" (available on the Division website) accompanied by the required fee and supporting documentation as listed on the form, to the Division at least 60 days prior to any one or more of the following events The sale or conveyance of the project area in whole or in part, except in the case of an individual lot sale that is made subject to the recorded deed restrictions and protective covenants, Dissolution of the partnership, corporate, or LLC entity, subject to NCGS 55-14-05 or NCGS 57D-6-07 and 08, Bankruptcy, Foreclosure, subject to the requirements of Session Law 2013-121, 5 Current Perm ittee Name or Address Changes The permittee shall submit a completed "Permit Information Update Application Form" (available on the Division website) to the Division within 30 days to making any one or more of the following changes a A name change of the current permittee, b A name change of the project, c A mailing address change of the permittee, 6 The permittee is responsible for compliance with all terms and conditions of this permit until the Division approves the transfer request Neither the sale of the project, in whole or in part, nor the conveyance of common area to a third party constitutes an approved transfer of the permit 7 The permittee grants Division Staff permission to enter the property during normal business hours to inspect all components of the permitted project 8 The permit issued shall continue in force and effect until the permittee files a request with the Division for a permit modification, transfer, renewal, or rescission, however, these actions do not stay any permit conditions 9 Approved plans, application documents, supplements, calculations, operation and maintenance agreement, and specifications for this project are incorporated by reference and are enforceable parts of the permit A copy of this permit, application, supplements, operation and maintenance agreement, and approved plans and specifications shall be maintained on file by the permittee 10 Unless specified elsewhere, permanent seeding requirements for the on -site stormwater system must follow the guidelines established in the North Carolina Erosion and Sediment Control Planning and Design Manual 11 The issuance of this permit does not prohibit the Director from reopening and modifying the permit, revoking and reissuing the permit, or terminating the permit for cause as allowed by the laws, rules, and regulations contained in Title 15A NCAC 2H 1000 and NCGS 143-215 1 et al 12 A permit renewal request must be submitted at least 180 days prior to the expiration date of this permit The renewal request must include the appropriate application, documentation and the processing fee as outlined in Title 15A NCAC 02H 1045(3) Page 4 of 5 State Stormwater Management Systems Permit No SW8 880910 Permit renewed, updated and reissued this the 13th day of September 2021 NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION , ,.Brian Wrenn, Uirector Division of Energy, Mineral and Land Resources By Authority of the Environmental Management Commission Page 5 of 5 Attachment C - Permitting History Ika Works North American expansion and Renovation Permit No SW8880910 Approval permit Action BIMS Description of the Changes Date Version 9/26/1988 Original 10 Approval The expansion of the existing facility and the demolition and re- design the existing parking lots resulting in the addition of 17,520 square feet of impervious area to the previously permitted drainage area The expansion of the existing wet detention pond to 1/25/2012 Modification I I incorporate a forebay also increases the permanent pool surface area and the provided storage volume Please note that the original design was based on the NGVD29 datum which is approximately 1 foot higher than NAVD88, which is why the elevations appear I foot lower than originally permitted The expansion of the project on to the adjoining property, which was previously permitted under SW8 130724, which has been rescinded effective January 15, 2016 The desire is to now more closely connect the development on these two parcels The expansion of the existing wet detention pond Please note that the original design was 1/15/2016 Modification 12 based on the NGVD29 datum which is approximately 1 foot higher than NAVD88, which is why the elevations appear 1 foot lower than initial permit The expansion of the drainage area for the wet detention pond to handle both the additional parcel as well as offsite runoff that cannot be routed around the stormwater collection system The offsite areas have been considered at the maximum build out potential 9/13/2021 Renewal 20 t% Permit Number (to be provided by DWQ) Drainage Area Number Wet Detention Basin Operation and Maintenance Agreement I will keep a maintenance record on this BMP Tlus maintenance record will be kept in a login a known set location Any deficient BMP elements noted in the inspection will be corrected, repaired or replaced immediately These deficiencies can affect the integrity of structures, safety of the public, and the removal efficiency of the BMP The wet detention basin system is defined as the wet detention basin, pretreatment mcludmg forebays and the vegetated filter if one is provided This system (check one) fE C E I VE ❑ does ® does not incorporate a vegetated filter at the et DEC 15 2015 This system (check one) ❑ does ® does not incorporate pretreatment other than afl8lu>•eba3c Important maintenance procedures — Immediately after the wet detention basm is established, the plants on the vegetated shelf and perimeter of the basin should be watered twice weekly if needed, until the plants become established (commonly six weeks) — No portion of the wet detention pond should be fertilized after the first initial fertilization that is required to establish the plants on the vegetated shelf — Stable groundcover should be maintained in the drainage area to reduce the sediment load to the wet detention basm — If the basin must be dramed for an emergency or to perform maintenance, the flushing of sediment through the emergency drain should be mmimized to the maximum extent practical — Once a year, a dam safety expert should inspect the embankment After the wet detention pond is established, it should be inspected once a month and within 24 hours after every storm event greater than 10 inches (or 15 inches if in a Coastal County) Records of operation and maintenance should be kept in a known set location and must be available upon request Inspection activities shall be performed as follows Any problems that are found shall be repaired immediately BMP element Potential problem How I will remediate the problem The entire BMP Trash/debris is present Remove the trash debris The perimeter of the wet Areas of bare soil and/or Regrade the soil if necessary to detention basin erosive gullies have formed remove the gully, and then plant a ground cover and water until it is established Provide lime and a one-time fertilizer application Vegetation is too short or too Maintain vegetation at a height of long approximately six inches Form SW401-Wet Detention Basin O&M -Rev 4 Page 1 of 4 Permit Number (to be provided by DWQ) Drainage Area Number BMP element Potential problem How I will remediate the problem The inlet device pipe or The pipe is clogged Unclog the pipe Dispose of the swale sediment off -site The pipe is cracked or Replace the pipe otherwise damaged Erosion is occurring in the Regrade the swale if necessary to swale smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid main treatment area Sediment has accumulated to source a depth greater than the sediment and remedy the problem if original design depth for possible Remove the sediment and sediment storage dispose of it in a location where it will not cause impacts to streams or Erosion has occurred Provide additional erosion protection such as reinforced turf matting or riprap if needed to prevent future erosion problems Weeds are present Remove the weeds, preferably by hand If pesticide is used, wipe it on the plants rather than spraying Best professional practices Prune according to best professional show that pruning is needed practices to maintain optimal plant health Plants are dead, diseased or Determine the source of the dying problem soils, hydrology, disease, etc Remedy the problem and replace plants Provide a one -tune fertilizer application to establish the ground cover if a soil test indicates it is necessary Weeds are present Remove the weeds, preferably by hand If pesticide is used, wipe it on the plants rather than spraying Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design sediment possible Remove the sediment and storage depth dispose of it in a location where it will not cause impacts to streams or the BMP Algal growth covers over Consult a professional to remove 50% of the area and control the algal growth Cattails, phragmites or other Remove the plants by wiping them invasive plants cover 50% of with pesticide (do not spray) the basin surface Form SW401-Wet Detention Basin O&M -Rev 4 ECEI V c DEC 15 2015 ge 2 of 4 BY Permit Number (to be provided by DWQ) Drainage Area Number BMP element Potential problem How I will remediate the problem The embankment Shrubs have started to grow Remove shrubs immediately on the embankment Evidence of muskrat or Use traps to remove muskrats and beaver activity is present consult a professional to remove beavers A tree has started to grow on Consult a dam safety specialist to the embankment remove the tree An annual inspection by an Make all needed repairs appropriate professional shows that the embankment needs repair if applicable) The outlet device Clogging has occurred Clean out the outlet device Dispose of the sediment off -site The outlet device is damaged Repair or replace the outlet device The receiving water Erosion or other signs of Contact the local NC Division of damage have occurred at the Water Quality Regional Office, or outlet the 401 Oversight Unit at 919-733- 1786 The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth readmg and not readily penetrate into accumulated sediments When the permanent pool depth reads 200 feet m the main pond, the sediment shall be removed When the permanent pool depth reads 2 00 feet in the forebay, the sediment shall be removed Sediment Removal Bottom 2828 00 ---------------- FOREBAY BASIN DIAGRAM (rill in the blanks) (ft Min Sediment Storage Form SW401-Wet Detention Basin O&M -Rev 4 Permanent Pool Elevation 30 00 Sediment Removal Elevation 28 00 Volum Bottom Elevation 27 00 J. 1-ft MAIN POND ECGI i0 E f DEC 15 2015 Page 3 of 4 BY Storage Permit Number (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the 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 Project name IKA Works North American Expansion and Renovation BMP drainage area number I Print name Reftka Bilaic Title Manaeme Director Address 2635 Northchase Parkway SE, Wilmington, NC 28405 Phony Signa 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 I, / v a Notary Public for the State of 1 I County of , do hereby certify that �} personally appeared before me this day of (�, and acknowledge the due execution of the forgoing weyiNention basin maintenance requirements Witness my hand and official seal, SEAL My commission expires P-1 ECEIVE DEC 15 2015 BY- 9 Form SW401-Wet Detention Basin O&M -Rev 4 Page 4 of 4 PermitNumber -, 1-a l f /O — (to be provided by DWQ)— Drainage Area Number Wet Detention Basin Operation and Maintenance Agreement I will keep a mamtenance record on this BMP This mamtenance record will be kept in a log in a known set location Any deficient BMP elements noted m the mspection will be corrected, repaired or replaced immediately These deficiencies can affect the integrity of structures, safety of the public, and the removal efficiency of the BMP 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) ❑ does ® does not incorporate a vegetated filter at the outlet This system (check one): ❑ does ® does not incorporate pretreatment other than a forebay. Important maintenance procedures — Immediately after the wet detention basin is established, the plants on the vegetated shelf and perimeter of the basin should be watered twice weekly if needed, until the plants become established (commonly six weeks) — No portion of the wet detention pond should be fertilized after the first initial fertilization that is required to establish the plants on the vegetated shelf — Stable groundcover should be maintained in the drainage area to reduce the sediment load to the wet detention basin — If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency dram should be mmunized to the maximum extent practical — Once a year, a dam safety expert should inspect the embankment After the wet detention pond is established, it should be inspected once a month and within 24 hours after every storm event greater than 10 inches (or 15 inches if in a Coastal County) Records of operation and maintenance should be kept in a known set location and must be available upon request Inspection activities shall be performed as follows Any problems that are found shall be repaired immediately BMP element Potential problem How I will remediate the problem The entire BMP Trash debris is present Remove the trash debris The perimeter of the wet Areas of bare soil and/or Regrade the soil if necessary to detention basin erosive gullies have formed remove the gully, and then plant a ground cover and water until it is established Provide lime and a one-time fertilizer application Vegetahon is too short or too Maintain vegetation at a height of long approximately six inches Form SW401-Wet Detention Basin O&M -Rev 4 RECEIVED JAN 1 ? Z01Z Page 1 of BY Permit Number (to be promded by DWQ) Drainage Area Number BMP element Potential problem How I will remediate the problem The inlet device pipe or The pipe is clogged Unclog the pipe Dispose of the swale sediment off -site The pipe is cracked or Replace the pipe otherwise damaged Erosion is occurring in the Regrade the swale if necessary to swale smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid future problems with erosion The forebay Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design depth for possible Remove the sediment and sediment storage dispose of it in a location where it will not cause impacts to streams or the BMP Erosion has occurred Provide additional erosion protection such as reinforced turf matting or riprap if needed to prevent future erosion problems Weeds are present Remove the weeds, preferably by hand If pesticide is used, wipe it on the plants rather than spraying The vegetated shelf Best professional practices Prune according to best professional show that pruning is needed practices to maintain optimal plant health Plants are dead, diseased or Determine the source of the dying problem soils, hydrology, disease, etc Remedy the problem and replace plants Provide a one-time fertilizer application to establish the ground cover if a soil test indicates it is necessary Weeds are present Remove the weeds, preferably by hand If pesticide is used, wipe it on the plants rather than spraying The main treatment area Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design sediment possible Remove the sediment and storage depth dispose of it in a location where it will not cause impacts to streams or the BMP Algal growth covers over Consult a professional to remove 50% of the area and control the algal growth Cattails, phragmites or other Remove the plants by wiping them mvasive plants cover 50% of with pesticide (do not spray) the basin surface FC,FC1' jvBD Form SW401-Wet Detention Basin O&M -Rev 4 JAN 1 7 2012 Page 2 of 4 BY Permit Number (to be provided by DWQ) Drainage Area Number BMP element Potential problem How I will remediate the problem The embankment Shrubs have started to grow Remove shrubs immediately on the embankment Evidence of muskrat or Use traps to remove muskrats and beaver activity is present consult a professional to remove beavers A tree has started to grow on Consult a dam safety specialist to the embankment remove the tree An annual inspection by an Make all needed repairs appropriate professional shows that the embankment needs repair if applicable) The outlet device Clogging has occurred Clean out the outlet device Dispose of the sediment off -site The outlet device is damaged Repair or replace the outlet device The receiving water Erosion or other signs of Contact the local NC Division of damage have occurred at the Water Quality Regional Office, or outlet the 401 Oversight Unit at 919-733- 1786 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 2 0 feet in the main pond, the sediment shall be removed When the permanent pool depth reads 2 0 feet in the forebay, the sediment shall be removed Sediment Removal Bottom 2800 1 ----------------- FOREBAY BASIN DIAGRAM 66I1 in the blanks) Lit Min Sediment Storage Permanent Pool Elevation 30 0 Sediment Removal Elevation 28 00 Volum, ---------------------------- ------ Bottom Elevation MAIN POND �I. �C�ME1�[T �ji>f14GE A2,r I�iCaw.ta�'� Tia a'ZL(stn)n� l4*0 R.ECEIVED 1-ft Storage Form SW401-Wet Detention Basin O&M -Rev 4 JAN 1 7 2012 Page 3 of 4 BY Permit Number (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the 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 Project name IKA Works North America Expansion and Renovation BMP drainage area number Print name Title Address 2E Phon Signa 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 N cic-F h Cq (off �) `(n , County of N� I Q(A t\ 6f lC, �do hereby certify that k� I�� \� q I C. personally appeared before me this 7 day of Q Lko p p_l= , 'k � l—, and acknowledge the due execution of the forgoing detention b sinsm ma a requirements Witness my hand and official seal, 11 JOLENE ROUTIER Notary Public, North Carolina New Hanover County My commission Expires October 09, 2012 SEAL My commission expires 16 /d� I I RECEIVED JAN 1 7 2012 BY Form SW401-Wet Detention Basin O&M -Rev 4 Page 4 of 4 FUUMST PLAZA I� lG lei o V E D operation and Maintenance Manual 11� SEP 1 3 1986 for M Storm Water Facility -�stoj A g !A General: The storm grater management system for this site is designed as a wet detention facility. The system consists of the wet detention pond located to the side and the rear of the building, a drawdown tube with a control orifice, a 24" RCP principal spillway culvert and a grassed emergency spillway. Operation: 'Lhe wet detention pond is designed to maintain a percent water pool with an average depth of 3 feet. The pond is designed to temporarily store an amount of water equivalent to 1 inch of storm water run-off from the inpervicus surfaces. In the event of a 1 inch rainfall, the wet detention pond is designed such that the water surface will rise approximately .62 feet above the normal pool level. This increase in water depth will slowly recede to the normal pool level in a 2 to 3 day time period. 2hi.s drawdown time is controlled by a 1-3/4 inch diameter orifice and 8" PVC drawdown pipe discharging to the downstream channel. In larger rain events, excess runoff is carried by the 24" reinforced concrete culvert. Rhis system is designed for the 10 year storm. A grassed emergency spillway is provided for storm events in excess of the 10 year storm. Maintenance: Several areas will need attention by maintenance personnel for the continued performance of this system as designed and as required by the Division of Environmental Management. 'these items are detailed as follows: 1. Grassing around the wet detention pond shall be maintained to prevent the erosion of these areas. Specific attention should be given to the emergency spillway following large rain events to repair any areas that have been eroded. The areas shall be periodically mowed to maintain the aesthetic quality of the site and to prevent a reduction in capacity of the storm water system. 2. The drawdown tube and trash screen shall be checked following meal cable rain events for accumulation of debris and cleared of any blockage that is present. If the water level following a rain event fails to recede to the normal pool elevation within the 2 to 3 day time period, the engineer must be notified as soon as possible. If the water level fails to recede within a period of 5 days following a rain event the owner must notify the Division of Environmental Management, 7225 Wrightsville Avenue, Wilmington, N.C., (919) 256- 4161. AI � 3. Storm drainage pipes and culverts shall be inspected periodically for debris and said build-up. These shall be cleaned as necessary to provide for the conveyance of storm water as designed. 4. The wet detention pond depth shall be maintained at the design depth. Mus is particularly important during the construction period since this basin will serves as part of the erosion control plan. Once ground cover is established on the site, the pond shall be inspected a minimum of every 6 months and cleaned as necessary. 5. No modifications shall be made to the system without notification of the engineer or without approval from the Division of Envircrmental Management. L)EMLK UbE UNLY _ — _ ___ _ _ __ _ _ _ — __ _ __ __ II a� �- NC DEQ Division of Energy, Mineral and Land Resources STATE STORMWATER: PERMIT RENEWAL APPLICATION FORM In accordance with 15A NCAC 2H 1045(3), the current permit holder shall renew their high density permit 180 days pnor to its expiration Renewed permits are valid for a period of 8 years per Session Law 2011-398 (SB 781) Section 60 (c) This application form is for permit renewals only A PROJECT INFORMATION 1 State Stormwater Permit Number SW8 880910 2 Project name 1KA Works Inc 3- Project street address 2635 Northcase pkwy SE City wilmington County New Hanover ZIP 28405 4 What, if any, changes have been made to the project as permitted? If the project has changed from the original approved plans, please complete SWU-101 for a Ma/or Modification or Minor Modification Application form available at https //deg nc gov/about/dwisions/energv- mineral-land-resources/energy-mineral-land-rules/stormwater-grog ram/post-construction B PERMITTEE INFORMATION If changes to the permittee orpro/ect name have been made, please complete either the Permit Update form or the Permit Transfer form available at https //deo nc gov/about/divisions/energy-mineral-land- resources/energy-mineral-land-rules/stormwater-program/post-construction State Stormwater Permits do not automatically transfer with the sale of the property 1 Current Permit Holder's Company Name/Organization IKA Works Inc 2 Signing Official's Name Jason Niloff 3 Signing Official's Title Chief Executive Officer 4 Mailing Address 2635 Northchase pkwv SE City wilmington 28405 5 Street Address same as above City State 6 Phone (910-) 452-7059 Email Jason mloff(g)ika net NC ZIP ZIP AUG 2 3 2021 BY Stormwater Permit Renewal Form Page 1 of 3 May 11, 2018 C SUBMITTAL REQUIREMENTS Submit the application package to the appropriate DEMLR Regional Office (Coastal, SA Waters) or DEMLR Central Office (Urbanizing Areas Ph 2, USMP, Non -Coastal HQW/ORW) Only applications packages that include all required items listed below will be accepted and reviewed Initial each item below to indicate that the required information is provided in the application package JN 1 A permit application processing fee of $505 00 payable to NCDEQ JN 2 One original signed hard copy and one electronic copy of this completed form The signing official named on this application to represent the current permittee must meet one of the following a Corporation — a principle executive officer of at least the level of vice-president, b Limited Liability Company (LLC) — a manager or company official as those terms are defined in G S 57D "North Carolina Limited Liability Company Act," c Public Entity — a principal executive officer, ranking official, or other duly authorized employee, d Partnership or limited partnership — the general partner, e Sole proprietor, or f Letter of authorization signed by one of the signatories noted in a — e above authorizing the signature of another entity JN 3 One hard copy and one electronic copy of recorded documents required by the original permit that have not yet been received by DEMLR, including deed restrictions, protective covenants, condominium/planned community declaration and easements If the project has been built, include documentation that the maximum BUA per lot or maximum total BUA has not been exceeded If the project has not been built, Include a signed agreement that the final recorded deed restrictions and protective covenants will be submitted at a later date JN 4 O&M Agreements, Please select one ❑ I have a copy of the current recorded O&M Agreement for all SCMs, and I will continue to keep this on file with the permit, or ® I do not have a copy of the current recorded O&M Agreement for all SCMs and am requesting a copy be sent tome I agree to keep this on file with the permit JN 5 Designer Certifications, Please select one ❑ A copy of the certlflcatlon(s) confirming that the project was built In accordance with the approved plans have been previously provided to the Division, or ❑ A copy of the certification(s) confirming that the project was built In accordance with the approved plans are enclosed, or ® The project has not yet been built 6 [IF APPLICABLE] If the project has been built, one original hard copy and one electronic copy of a signed, sealed, and dated letter from a licensed professional stating that the SCMs have been inspected, and that they have been built and maintained In accordance with the permit 7 [IF APPLICABLE] When the permlttee Is a corporation or a limited liability corporation (LLC) Provide one hard copy and one electronic copy of documentation from the NC Secretary of State, or other official documentation, which supports the titles and positions held by the persons listed In Section C 2 per 15A NCAC 2H 1043(3)(b) AUG 13 2021 ' BY Stormwater Permit Renewal Application Form Page 2 of 3 May 11, 2018 D PERMITTEE'S CERTIFICATION I, J4SON N11/0Fr- , the person legally responsible for the permit, certify that I have a copy of the Permit and O&M Agreement on site (or I will obtain a copy and it will be kept on site), that I am responsible for the performance of the maintenance procedures, and the site has been and will be maintained according to the O&M Agreement and approved plans I agree to notify DEMLR of any problems with the SCMs or built -upon area to su it the proper modify or transfer the permit prior to any changes to the protect, SCM r ownershi All a ded on this permit renewal application is, to the best of my knowledg ,correct and m Signal that this the day of County of execution of the forgoing instrument Witness my hand and official seal, (Notary Seal) Notary Signat a My commission expires a Notary Public for the State of do hereby certify personally appeared before me , and acknowledge the due LUZ VELEZ Notary Public - North Carolina Brunswick County My Commission Expires Apr 30 7024 AVG 2 3 2021 BY_ Stormwater Permit Renewal Application Form Page 3 of 3 May 11 2018 IV SUJ r vl -D rl ,M - 11Y69 VIL f,.d, �f Y;rerl ��n.•wi5 e "Cl N IqA I-"Q,3 ,A,1 m1 �a � ►� I�Ih�,1, � I � I f I�� February 15, 1993 Ms Linda Lewis Division of Environmental Management ENGINEERS 127 Cardinal Drive Extension Wilmington, NC 28405-3845 SURVEYORS RE Forrest Plaza Phases I & II ARCHITECTS Stormwater Project No 880910 PLANNERS Stormwater Project No 920411 Dear Linda M&C450-0022 RECEIVED FEB 18 1993 Wdmmeton Regional Offic8 DEM This letter is to complete the Stormwater permit requirements for Phases I and II of Forrest Plaza project in New Hanover County I, A Street Lee, as a duly registered Professional Engineer in the State of North Carolina hereby state that, based on site observation at the completion of this project, that construction of the stormwater facilities appears to be in substantial compliance and intent of the approved plans and specifications Signature '2 Registration No 14921 Date Z�4g�t) Ijk cc Bill Owen Chuck Agnoff 243 NORTH FRONT STREET WILMINGTON NC 28401 9191343 1048 FAX 919/251 8282 �.•`'��N CAR01/' •o ,•'`ti'�.�FESSf0y9ti ma's c� SEAL i 14921 r s �'FN61 NEFae'' • q • �F, r ��''•.,sTREET ��.•. NORMWAYR I��un(UUU FEB 1 9 1993 U DENT •Zo1 # Gk204.1 i-goi D Permit No ( 1 l 1 do be Pmvded by DWDI k . A NC ENR STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form must be filled out printed and submitted The Required Items Checklist (Part III) must be printed filled out and submitted along with all of the required information Patted name Contact person Plane number Date Drainage area number 1I6R076 1 II .DESIGN INFORMATION,,- -+ .. a T, Site Characteristics Drainage area 700559 fl2 — U��,n4b Sh� h I a7$1511:E� CrJ I,S Impervious rImpervious post development 344,541 h - 171 ,1$'a �}l Design rainfall depth 10 and 15 in Storage Volume Non SA Waters Minimum volume required 35579 ft' Volume provided 35,637 ft" OK volume provided is equal to or in excess of volume required Storage Volume SA Waters 15 runoff volume N/Aft° Pre -development 1 yr 24-hr mm0 to Post development i yr 24-hr mno8 ft' Minimum volume required It, Volume provded fto Peak Flow Calculations Is the prelpost control of the lyr 24hr stone peak flow regmredo N (Y or N) 1 yr 24-hr rainfall depth in Rational C pre-developmera (undless) Rational C post -development (umtless) Rainfall intenvty 1-yr, 24 hr stone Mhr Pre -development 1 yr 24 hr peak flow 4 22 ftafsec Past -development 1-yr 24-hr peak flow ft'/sec Pre/Post 1 yr 24-hr peak flow conlml ft"/sec Elevations Temporary pool elevation 3080 mist Permanent pool elevation 3000 final SHWT elevation(appmz at the pen pool elevation) N/A best Top of 1 Oft vegetated shelf elevation 3050 hest Bottom of 10ft vegetated shell elevation 2950 frost Sediment deanout top elevation (bottom of pond) 2800 final Sediment deanout bottom elevation 2700 first Sediment storage provided 100 ft Is (here additional volume stored above the state required temp pool? Y (Y or N) Elevation of the top of the additional volume 308 feel OK Form SW401 Wet Detention gasio-Rev 94118112 EC�� JAN 11 2016 BY Pans 1 611 Desgi Summery Page i of 2 Permit No (to De provWed by OWQ) 11, DESIGN INFORMATION Surface Areas Area lemporary pod Area REQUIRED, permanent pool SAW ratio Area PROVIDED permanent pool Ar„,,,, Area bottom of IOft vegetated shelf Ati a,er Area, sediment deanout top elevation (bottom of pond) Aso, Volumes Volume, temporary pod Volume permanent pod Vim,,,, Volume forebay (sum of forebays it more than one tomboy) Forebay %of permanent pool volume SAIDA Table Data Design TSS removal Coastal SAIDA Table Used? MountainlPiedmonl SAIDA Table Used? SAIDA rako Average depth (used in SAIDA table) Calculation opbon 1 used? (See Figure 10-2b) Volume permanent pool V._p Area provided, permanent pool A en,,_pp Average depth calculated Average depth used in SAfDA it. (Round to nearest 0 5ft) Calculation option 2 used? (See Figure W-21b) Area provided permanent pool A..,, Area bottom of 10ft vegetated shelf Awl ,, 47 498 fly 38 601 ft 551 (uncles) 40537 fit' OK 34,171 fte 25871 ft 35637 rye OK 86,863 fte 17 252 rye 19 9% % OK 90 % Y (Y or N) N (Y or N) 551 funNm N (Y or N) 86 663 ft' 40 537 ft' It Need 3ft min ft N (Y or N) 40 537 ft" 34171 IF Area sediment deanout top elevation (bottom of pond) Am. _ 25871 fte 'Depth' (distance bhv bottom of 1Tft shelf and top of sediment) 150 ft Average depth calculated 300 ft OK Average depth used in SAIDA J. (Round to down to nearest 0 5ft) 3011 OK Drawdown Calculations Drawdown through onfice7 Diameter of onfice (d circular) Area of onfice (if -non -circular) Coefficient of discharge (Cn) Driving head (Ho) Drawdown through weir? Wentype Coefficient of discharge (Q Length of weir (L) Driving head(H) Pre -development 1 yr 24 hr peak flow Post -development 1 yr, 24 hr peak flow Storage volume discharge rate (through discharge orifice a weir) Storage volume drawdown time Additional Information Vegetated side slopes Vegetated shelf slope Vegetated shelf width Lengtn of Towpath to width mtw Length to width ratio Trash rack for overflow 8 onficev Freeboard provided Vegetated filter provided? Recorded drainage easement providedo Capures all runoff at ultimate build -cut? Dram mechanism for maintenance or emergencies is Y (Y or N) 300 in m' 0 60 (umdess) 021 It N (Y or N) (umtless) (unifless) It It 4 22 ftelsec ft'Isec 011 ftelsec 352 days 31 10 1 100 It 16 1 160 1 Y (Y or N) 13ft NIA._ (Y or N) I'0 / FAS—Lo oN OK draws down in 2 5 days OK OK OK OK OK OK OK OK OK OK FN=CFIVE RR � I P JAN 1 1 2016 BY Forn S W401 Wet Detention Basin Rev 9 4118112 Parts I a 11 Design Summary Page 2 of 2 Permit No (to be provided by DWQ) III REQUIRED ITEMS CHECKLIST Please Indicate the page or plan sheet numbers where the supporting documentation can be found An incomplete submittal package will result in a request for additional information This will delay final review and approval of the project Initial in the space provided to Indicate the following design requirements have been met If the applicant has designated an agent, the agent may Initial below If a requirement has not been met, attach justification Page/ Plan e-tVials Sheet No l3_ (0 -11 Plans (1"- 50' or larger) of the entire site showing - Design at ultimate build -out, - Off -site drainage (if applicable), - Delineated drainage basins (include Rabonal C coefficient per basin), - Basin dimensions, - Pretreatment system, - High flow bypass system, - Maintenance access, - Proposed drainage easement and public right of way (ROW), - Overflow device, and - Boundaries of drainage easement .Q2 Partial plan (1" = 30' or larger) and details for the wet detention basin showing - Outlet structure with trash rack or similar, - Maintenance access, Permanent pool dimensions, Forebay and main pond with hardened emergency spillway, - Basin cross-section, - Vegetation specification for planting shelf, and - Filter strip to -(�fa , W 3 Section view of the wet detention basin (1"= 20' or larger) showing - Side slopes, 3 1 or lower, - Pretreatment and treatment areas, and -Inlet and outlet structures f,0 • (C,G•��4 If the basin Is used for sediment and erosion control during construction, clean out of the basin Is specified on the plans prior to use as a wet detention basin +C I 5 A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for forebay, 4i verify volume prowled • C�•N l A 6 A construction sequence that shows how the wet detention basin will be protected from sediment until the entire drainage area is stabilized ILA-Lsi 7 The supporting calculations i 0 *'An 8 A copy of the signed and notarized operation and maintenance (0&M) agreement - AL/A-- 9 A copy of the deed restrictions (if required) t } G�kLt t 10 A soils report that is based upon an actual field investigation, soil borings, and infiltration tests County soil maps are not an acceptable source of soils information Form SW401-Wet Detention Bas n-Rev 9-4/18/12 ECEIVE DEC 15 2015 BY. Part III Required ItemsZFe_cRRT Page 1 of 1 Permit No �,1al U 1/O (to be Orovrled by DWO) MA&- NCDENR STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form must be filled out printed and submitted The Required Items Checklist (Part III) must be printed, filled out and submitted along with all of the required information Project name Contact person Phone number Dale Drainage area number Site Characteristics Drainage area Impervious area post -development % Impervious Design rainfall depth Storage Volume Non SA Waters Minimum volume required Volume provided Storage Volume SA Waters 1 5' runoff volume Pre -development 1 yr, 24-hr runoff Post -development I yr 24 hr runoff Minimum volume required Volume provided Peak Flow Calculations Is the prelpost control of the tyr 24hr storm peak flow required? 1 yr 24-hr rainfall depth Rational C pre -development Rational C post development Rainfall Intensity 1-yr 24 hr storm Pre -development 1-yr 24 hr peak flow Post -development i yr 24 hr peak flow Pre/Post 1-yr 24 hr peak flow control Elevations Temporary pool elevation Pemwnenl Pool elevation SHWT elevation (approx at the perm pool elevation) Top of 1 Oft vegetated shelf elevation Bottom of 1Oft vegetated shelf elevation Sediment cleanout, top elevation (bottom of pond) Sediment cleanout bottom elevation Sediment storage provided Is there additional volume stored above the state -required temp pooln Elevation of the top of the additional volume Form SW401 Wet Detention Basin Rev 8-9117109 IKA Works. Inc under Forest Plaza I ATOP WA7fgq A s 1112/2012 Proposed Improvements to Extshng On Site Drainage Area (Combined Calculations) 19730 ft2 ISM,}79 (9 1 o" a- 44y.<78 O ! s" : I "I l Ta4-S�F 116727 ftz(`If, 1-0—� 3F 0D 1. 04 t 1:1, SU SF O 1. 5"= flee, -72'1 So 5915 % COMPOS(TC 1# 10and 15m 10573 ft' ( 641-L 0F ® le -0 21-`#�ALUEIe ( Sir= fob Sl3 CF� 10.576 0 OK volume provided is equal to or In excess of volume required NA ft' ft' ft' n' n' N (Y or N) in (umdess) (unitless) in/hr NA ft'/sec NA ft'Isec #VALUEI III/sec 3069 fmsl 3000 fmsl N/A fmsl W R6Ro Its oP61Nh1— 1188 P6Ifr411' NIA fmsl (h ) N/A fmsl ( u 2800 fmsl 2700 fmslrORl[rtPA-L. 607'I' M gam• W-11raP E9 100 ft l N&M DkNn tN I4S.8 WAK tjAvp29 Fly p.E OMP se 2 B •O Y (Y or N) '�FII�� IJA'VO�tj� 307 fmsl Insufficient Must equal the temp pool elev previously entered RECEIVED Pans I a tl Design Summary Page 1 of 2 JAN 1 7 Z011 BY Permit No (m ffe pmvded by DWp) l � II DESIGN INFORMATION Surface Areas Area, temporary pool Area REQUIRED permanent pool SAIDA ratio Area PROVIDED permanent pool A._pw Area, bottom of 10ft vegetated shelf Ayrt s,df, Area, sediment deanoul top elevation (bottom of pond) Awy, Volumes Volume temporary pool Volume, permanent pool Vp -PW 20 1" Volume, forebay (sum of forebays if more than one forebay) Forebay %of permanent pool volume SAIDA Table Data Design TSS removal Coastal SAIDA Table Used? Mountain/Piedmont SAIDA Table Used? SAIDA ratio Average depth (used in SAIDA table) Calculation option 1 used? (See Figure 10 2b) Volume permanent pool Vp„ _Pot Area provided permanent pool A._. Average depth calculated Average depth used in SAIDA d.. (Round to nearest 0 511) Calculation option 2 used? (See Figure 10 2b) Area provided permanent pool A._p, Area bottom of 10ft vegetated shelf Av„ ,, 16 557 ft' 13 596 ft' 6 89 (umlless) CiA/64 agw9 op 59 Z0/o lw 3 0 Avf,- be") 14 098 ft` OK N/A ft, 2 579 ft` /'Wgl(rkr-BA6lVD V6�� °F PtP6D-o�4+Pj46 ?o#a 16,251 ft'al KA=-�k(141kG) (�% 0,571OF �'r7 �a lk VA 2923 ft' 3l4'0 ,c Z.pl IG6 cr- = Gt251 468% % Insufficient forebay, volume fumep Fotgrb" uD 90 % �/iTlvrGMr10A1 p►-oviOSD flit Nq kT1vE Y (Y or N) N (Y or N) 689 (umlless) N (Y or N) 6 251 ft' 143 00 ft` 3ooPERAA�D �. YT%�) It ol�b��+NAt (4� 30 ft OK N (Y or N) 14 098 fte NA ft Area sediment deanout, top elevation (bottom of pond) A,. 2,579 fte 'Depth' (distance Not bottom of 1011 shelf and lop of sediment) #VALUE' It Average depth calculated NA It OK Average depth used in SAIDA d„ (Round to nearest 0 511) 30 It #VALUE' Drawdown Calculations Drawdown through onfice? Diameter of onfice (if circular) Area of onfice (if non -circular) Coefficient of discharge (Co) Driving head (He) Drawdown through weir/ Weir type Coefficient of discharge(C,.) Length of weir (L) Driving head (H) Pre -development 1 yr 24-hr peak flow Post development 1 yr 24-hr peak flow Storage volume discharge rate (through discharge onfice or weir) (RSa Y (Y or N) pW&Yr4A'LA Pe-Ka1(YTep "-IFIe) 175 in Enter ether diameter of onfice or area of non -circular onfice Do not enter NIA m2 both diameter and area for a circular onfice 0 60 (unites$) 021ft N (Y or N) NA (umlless) NA (umtless) NA It NA It NA ft'/sec NA ft'/sec 001 fi'/sec Storage volume drawdown bme 3 36 days OK, draws down in 2 5 days Additional Information Vegetated side slopes 3 1 OK Vegetated shelf slope NA 1 OK Vegetated shelf width NA ft OK Length of towpath to width ratio 12 1 OK Length to width ratio 120 1 OK Trash rack for overflow 8 onfice? Y (Y or N) OK Freeboard provided 4 3 ft OK vq OF PoNG - 315 D Vegetated filter provided? N (Y or N) OK 14.T JUQXACQ1! SiO Recorded drainage easement provided? Y (Y or N) OK Capures all runoff at ultimate build-outy Y (Y or N) OK Drain mechanism for maintenance or emergencies is PORTABLE SUMP PUMP Form SW401 Wet Detention Basin Rev a 9I17/09 RECEIVED Ports I a II Design Summary Page 2 of 2 JAN 1 7 2012 BY Permit No (to be provided by DWq) Ill REQUIRED ITEMS CHECKLIST Please Indicate the page or plan sheet numbers where the supporting documentation can be found An incomplete submittal package will result in a request for additional information This will delay final review and approval of the protect Initial in the space provided to indicate the following design requirements have been met If the applicant has designated an agent, the agent may Initial below If a requirement has not been met, attach justification Pagel Plan Initials Sheet No RAM CG101ICN501 1 Plans (1" - 50' or larger) of the entire site showing - Design at ultimate build -out, - Off -site drainage (if applicable), - Delineated drainage basins (include Rational C coefficient per basin), - Basin dimensions, - Pretreatment system, - High flow bypass system, - Maintenance access, - Proposed drainage easement and public right of way (ROW), - Overflow device, and - Boundaries of drainage easement RAM CN502 2 Partial plan (1" = 30' or larger) and details for the wet detention basin showing - Outlet structure with trash rack or similar, - Maintenance access, - Permanent pool dimensions, - Forebay and main pond with hardened emergency spillway, - Basin cross-section, - Vegetation specification for planting shelf, and - Filter strip RAM CN503 3 Section view of the wet detention basin (1" = 20' or larger) showing - Side slopes, 3 1 or lower, - Pretreatment and treatment areas, and - Inlet and outlet structures NA NA 4 If the basin is used for sediment and erosion control during construction, clean out of the basin is specified on the plans prior to use as a wet detention basin RAM Narrative 5 A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for Forebay, to verify volume provided NA NA 6 A construction sequence that shows how the wet detention basin will be protected from sediment until the entire drainage area is stabilized RAM Narrative 7 The supporting calculations RAM Included 8 A copy of the signed and notarized operation and maintenance (0&M) agreement RAM Included 9 A copy of the deed restnctions (if required) RAM Included 10 A soils report that is based upon an actual field investigation, soil borings, and infiltration tests County soil maps are not an acceptable source of soils information RECEIVED JAN 1 7 2012 Form SW401 Wet Detention Basin -Rev 8-9/17/09 Part III Required Items Checklist Page 1 of 1 BY Permit No SGUE (to be prat-ded by DiPQ State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT 4PPLICATION 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 Contact Person Phone Number 6100-SZ —1059 For projects with multiple basins, specify which basin this worksheet applies to elevations Basin Bottom Elevation ft (floor of the basin) Permanent Pool Elevation 3 1 a ft (elevation of the orifice) Temporary Pool Elevation J 1 &9 ft (elevation of the discharge structure overflow) areas Permanent Pool Surface Area (t t 0'5 sq ft (water surface area at the orifice elevation) Drainage Area 453 ac (on -site and off -site drainage to the basin) Impervious Area 91 ZO ae Z (on -site and off -site drainage to the basin) volumes Permanent Pool Volume h-i A cu ft (combined volume of main basin and forebay) Temporary Pool Volume 649 2- cu ft (volume detained above the permanent pool) Forebay Volume t-JI A cu ft (approximately 20% of total volume) Other parameters SA/DAi 5 ('�c10 (surface area to drainage area ratiofrom DWQ table) Diameter of Orifice 7 5 in (2 to 5 day temporary pool draw -down required) Design Rainfall in Design TSS Removal 2 90 % (minimum 85%required) Fonn SWU-102 Rev 3 99 Page I of 4 Footnotes When using the Dtvtsion SA/DA tables the correct SA,DA rno for permarent pool sizing bhould be computed based uoon the actual impervious % and permanert pool depth Linear interpola,ion should oe emploved to determine the correct salue 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 pro% ide 90% TSS removal The NCDENR 81,1P manual provides debt tables for both 35% TSS removal and 90% TSS renim al II REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements pet 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 requi*ements 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) 01 / 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 _ 1 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 3 014 It A submerged and vegetated perimeter shelf with a slope of 6 l or less (show detail) i Vegetative cover above the permanent pool elevation is specified I A trash rack or similar device is provided for both the overflow and orifice NI,A k A recorded drainage easement is provided for each basin including access to nearest right- of-way 0A. l 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 LX in A mechanism is specified which will dram the basin for maintenance or an emergency 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 O'{loes not This system (check one) 0 does oes not incorporate a vegetated filter at the outlet incorporate pretreatment other than a forebay Form SWU-102 Rev 399 Page 2of4 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 Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative cover to maintain a maximum height of sir 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) 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 measunng 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 :7.0 ' feet in the main pond, the sediment shall be removed When the permanent pool depth reads J�A feet in the forebay, the sediment shall be removed BASIN DIAGRAM (fill in the blanks) - - Permanent Pool Elevation 31 �! Sediment Ret oval El -- 75 ° Sediment Removal Elevanon 2b.0 75% Bottom Etc anon % -' - Bottom Elevation Z& 0 2 5 %. FOREBAY - NIA MAIN POND 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 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 FomSWU-102 Rev 399 Page 3of4 All component of the wet detention basin system shall be maintained in good work'ng order I acknowledge and agree by my signature belo,,� that I am responsible for the performance of the se�cn maintenance proi.edures listed above I agree to notify DW Q of any problems with the system or prior to any changes to the system or responsible party Print / Title /Addr /Phone rf-(a, q_-S1L '/Signe `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 / I ?-� E-� 11� �sey a Notary Public for the State of ,V � , County of�� do by certify that Y1P_ personally appeared before me this �_ dayof , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements Witness my hand and official seal, ,CCCA A 0):, ,xo-VAR), U z ze y PUB0 r . 't, 41, OVER CCJ SEAL My commission expires Form SWU-102 Rev 3 99 Page 4 of 4 IKA Works Stormwater Permit No SW8 880910 New Hanover County Designer's Certification State Stormwater Management Systems /^ J Permit No SW8 880910 �I I, �C ' 2O'-&x? x, as a duly registered 'r ltra.�/ co;Jt i%m the State of North Carolina, having been authorized to observe euedtea{Ip/-weekly/ full time) the construction of the protect, (Project) for , k4 W b( k y C�- (Protect Owner) hereby state that, to the best of my abilities, due care and diligence was used in the observation of the protect 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 specifications QLSignature _ Registration Number Date 91,:9c4%o?o/ 7 ECEIVE SEP 2 5 2013 BY--------_ SEAL Page 7 of 8 State Stormwater Management Systems Permit No SW8 880910 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 protect 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 structure elevations are per the approved plan 6 The outlet structure is located per the approved plans 7 Trash rack is provided on the outlet 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 _4,,/ 12 Required drawdown devices are correctly sized and located 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 16 All components of the stormwater BMP are located in either recorded common areas, or recorded easements cc NCDENR-DWQ Regional Office New Hanover County Building Inspections