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HomeMy WebLinkAboutSW8970128_HISTORICAL FILE_20181019STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW8 011 G 12cd DOC TYPE ❑ CURRENT PERMIT APPROVED PLANS HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE IoWo l ct YYYYMMDD NORRIS & TUNSTALL CONSULTING ENGINEERS, P.C. J. Phillip Norris, P.E. John S. Tunstall, P.E. T. Jason Clark, P.E. 902 Market Street • Wilmington, NC 28401-4733 • Phone (910) 343-9653 • Fax (910) 343-9604 1429 Ash Little River Road NW • Ash, NC 28420-1715 • Phone (910) 287-5900 • Fax (910) 287-5902 LETTER OF TRANSMITTAL To: Christine Hall Date: October 10, 2018 11 Job No 16121 NC DEQ - Stormwater Subject: UNCW Allied Health & Human Services Building (Package C Update) State SW Permit #: SW8 970128 WE ARE SENDING YOU VIA HAND DELIVER ❑ ATTACHED ❑ UNDER SEPARATE COVER ❑ SHOP DRAWINGS ® PRINTS ❑ CERTIFICATION ❑ SPECIFICATIONS ❑ DISKS ❑ COPY OF LETTER ❑ FAX TRANSMITTAL: NUMBER OF PAGES INCLUDING THIS TRANSMITTAL Call 910-343-9653 If you have any difficulty receiving this message. COPIES DATE NO. DESCRIPTION 2 04-11-18 R1 L151 - Grading Plan by Surface �cE OCT 12 2018 r re��e h ® AS REQUESTED ❑ FOR YOUR USE ❑ FOR REVIEW AND COMMENT ❑ FOR BIDS DUE ❑ FOR APPROVAL ❑ YOUR PRINTS LOANED TO US REMARKS: Per your e-mail to Jason Clark, P.E. of today, for approval of State SW Permit #SW8 970128. Thank you — - CC: SIGNED John S. Tunstall, P.E. / asn CONFIDENTIAL AND PRIVILEGED Information contained in this document is privileged and confidential, intended for the sole use of the addressee. If you are not the addressee or the person responsible for delivering it to the addressee you are hereby notified that any dissemination, distribution or copying of this document is strictly prohibited If you have received this document in error please immediately notify the sender and return to the address above. Hall, Christine From: Jason Clark <jclark@ntengineers.com> Sent: Wednesday, October 10, 2018 10:40 AM To: Hall, Christine Cc: Amy Norris Subject: [External) Re: SW8 970128 Attachments: image003 prig o Extemal email oo not click links or open attachments unless verified` Send all suspicions emaitas an attachment Yo N Christine, Thank you. I will provide you two copies of that plan sheet. T. Jason Clark, PG NORMS & TUNSTALL CONSUCPING ENGINEERS P.C. 902 Market Street, Wilmington, NC 28401 910-343-9653 (Ext 202) 1 910-343-9604 (F) iclark(�ntenglneers.com It is the professional opinion of Norris & Tunstall Consulting Engineers, P.C. and Norris, Kuske & Tunstall Consulting Engineers, Inc that this electronic information provides design information current as of the date of its release. It shall be the responsibility of the party receiving the data to examine it to see that it contains the necessary files and information requested In transferring the files in electronic media format, Norris & Tunstall Consulting Engineers, P.C. and Norris, Kuske & Tunstall Consulting Engineers, Inc. makes no representations as to the usability or readability of documents resulting from the use of software application packages, operating systems, or computer hardware differing from those used by Norris & Tunstall Consulting Engineers, P.C. and Norris, Kuske & Tunstall Consulting Engineers, Inc. in the preparation of such data. From: Christine Hall <christine.haII ncdenr.eov> Date: Wednesday, October 10, 2018 at 10:32 AM To: Jason Clark <iclark@nteneineers.com> Subject: SW8 970128 Jason, I've finished looking over the minor mod to SW8 970128. The only thing I need is 2 copies of the grading plan (1-151) to support the new drainage areas. The storm drainage and the roof drainage plans provided for SW8 970128 don't quite give enough info on the pervious areas to support the change in the DA. Thank you! Christine Hall Environmental Engineer Division of Energy, Mineral and Land Resources — State Slormwater Program Department of Environmental Quality 910 796 7215 office 910 796 7335 direct christine.hall(a)ncdenr gov 127 Cardinal Drive Ed. Wilmington, NC 28405 �/ Nothing Compares-... Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties. Burd, Tina J From: Burd, Tina 1 Sent: Tuesday, July 31, 2018 11:46 AM To: 'mbrganm@uncw.edu'; 'jclark@ntengineers.com'; 'anorris@ntengineers.com Subject: SW8 970128 - Honors, International Privatized Housing The Wilmington Regional Office of the Division of Energy, Mineral and land Resources (Stormwater Section) accepted the Stormwater Permit Minor Modification application for the subject project on July 30, 2018. The project has been assigned to Christine Hall and you will be notified if additional information is needed. Please be advised that the construction of built -upon area may not commence until the Stormwater Permit is issued. Tina Burd Administrative Associate II Wilmington Regional Office Division of Environmental Assistance & Customer Service Phone 910-796-7388 NCDEQ Wilmington Regional Office 127 Cardinal Drive Ext. Wilmington, NC 28405 Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties. I :. STORMWATER CALCULATIONS UNC WILMINGTON - HONORS, INTERNATIONAL, AND PRIVATIZED ROUSING, AND ASSOCIATED PARKING LOT IMPROVEMENTS PHASE 1 (SW8 970128) Wilmington, North Carolina For UNC-Wilmington 601 South College Road Wilmington, NC 28403 (910)962-3719 �( SEAL 0 gSON June 2018 Prepared by: NORRIS & TUNSTALL CONSULTING ENGINEERS, P.C. 902 Market Street Wilmington, North Carolina 28401 (910)343-9653 (910) 343-9604 (Fax) License # C-3641 N&T Project No. 16121 5 Date Design% NORMS & TUNSTALL Wilmington, NC ENGINEERSP.C.� Brunswick County, NCOf :SheetCONSULTING Check Jodi rlNct,�r Algal Jl l! For Job No. 166z �ee_-_P_c��tl n O_CF_--- 14 _— _ _lye - .'—r _i� _� :. - _ C! (C_ — . (li'_4G ----I- ---- - _; I__—_ ---- IrTs -_ I �_—..-... -- — - -i I -- --- ----- ---- Ski--- =_ =ki _ �� I3�sF. - j- - -- -; - I - - I I --13 I --- _ I I _ i I i NCDEQ Stormwater Design Manual JU Table 1: Piedmont and Mountain SA/DA Table (Adapted rroln Driscoll, 1986) 10% 0.51 0.43 0.37 0.30 0.27 0.25 20% 0.84 0.69 0.61 0.51 0.44 0.40 30% 1.17 0.94 0.84 0.72 0.61 0.56 40% 1.51 1.24 1.09 0.91 0.78 0.71 50% 1.79 1.51 1.31 1.13 0.95 0.87' 60% 2.09 1.77 1.49 1.31 1.12 1.03 70% 2.51 2.09 1.80 1.56 1.34 1.17 80% 2.92 2.41 2.07 1.82 1.62 1.40 90% 3.25 '2.64 2.31 2.04 1.84 1.59 100% 3.55 2.79 2.52 2.34 2.04 1.75 Table 2: Coastal SA/DA Table (Adapted from Driscoll, 1986) 10% 0.78 0.61 0.44 0 0 0 20% 1.48 1.04 0.87 0.70 0.52 0.35 30% 2.18 1.65 1.39 1.13 0.87 0.70 40% 2.96 2.25 1.83 1.39 0.96 0.78 50% 3.65 2.87 2.33!5' 1.83 1.31 1.96 S2./0 60% 4.35 3.31 .26 1.74 1.13 70% 5.22 3.92 3.22 2.52 1.83 1.31 80% 5.92 4.52 3.65 2.78 1.91 1.57 90% 6.53 5.05 4.18 2.96 2.44 1.74 100% 7.13 5.92 4.87 3.83 2.78 1.83 2-9 JUL 3 0 2013 -- - BY:� C-3. Wet Pond 7 Revised: 4-18-2017 Drawdown Calculations Drainage Area = 33.46 AC Normal Pool = 24 ft Temporary Pool = 25.3 ft Volume to be drawn down = 76808 CF Drawdown Orifice: Avg. Head = 1/3 of Flood Pool Elev 0.43 ft Cp = Coefficient of Discharge "; i! � {"," N: �;,0;6.0 Drawdown Time = 2.00 days 172,800 s Internal Diameter = 0.42 ft 5.07 in Drawdown Time = 5.00 days 432,000 s Internal Diameter= 0.27 ft 3.21 in Avg Internal Diameter= 4.14 in Design Orifice Diameter = 5:O1) in OK! 0.14 ft Design Drawdown rate 0.43 cfs Design Drawdown time 2.06 days EGE1%W"E JUL 3 0 1113 By: Application Completeness Review Checklist Project Name: (2rjc (d (.�j. -S L �� �z��.,,/� Date Delivered to WIRO: Jc.5- ua 'a81MS Received/Accepted Date: ' J zr�J�j Project County;Location: /cc r kx< -c *BIMS Acknowledged Date: Rule(s): ®2017 Coastal 2008 Coastal ®1995 Coastal ®Phase 11 ®Universal 01988 Coastal Permit Action: New / Major Mo Minor Mod /Jenewal / Transfer **New Permit #: Type: HD / LD / LD Overall / Combo neral Permit / Offsite / Exempt / Rescission A Type(s): Type: / Residential / Other Permit #• ®PE Cert on File? to SWB: ❑Master PE Cert on File? For New or Transferred Permits Permittee is: Stream Class: Property Owner(s) ®Developer Lessee ®Purchaser [—]HOA ❑SA Map E]ORW Map Pape ork Emailed Engineer on: Sup ement(s) (1 original per BMP) O& with correct/original signatures (1 original per 8MP except LS/VFS and swoles) Application with correct/original signatures ❑Corp or LLC: Sig. Auth. per SoS or Signature Authorization letter or report ®$505 (within 5mo) Check#(s): o Fee �C}Is Report: w/SHWT or General Report Calculations (signed/sealed) Deed Restrictions, if subdivided: *Signed & Notarized Template Recorded Covenants Recorded Plats MSO` o or more Lots Sold List Project Narrative "USGS Map Plans E31'*Sets Vicinity Map Legend MDA Maps Existing Conditions Grading REVIEWER NAME: ®Wetlands: Delineated or No Wetlands Boundaries yout (proposed BUA dimensions) Email Address: Design Engineer Email Address: Property Owner Deed Email Address: Lessee Lease Agreement Email Address: Purchaser Purchase Agreement Email Address: Developer Email Address: HOA Representative ils (roads, cul-de-sacs, curbs, sidewalks, BMPs, Buildings, etc) ndscape Plan NOTES TO REVIEWER: *Enter BIMS Acknowledged Date on this Sheet **FOR NEW Projects -Enter New Permit # on Supplements & Deed Restiction Templates. G WQ\\\Reference Library\Procedures\Checklists\Completeness Review Checklist 2018 03 13 STORMWATER SYSTEM & EROSION CONTROL NARRATIVE UNC WILMINGTON - HONORS, INTERNATIONAL, AND PRIVATIZED HOUSING, AND ASSOCIATED PARKING LOT IMPROVEMENTS PHASE 1 (SW8 970128) Wilmington, North Carolina For UNC-Wilmington 601 South College Road Wilmington, NC 28403 (910) 962-3719 July 2018 Prepared by: NORRIS & TUNSTALL CONSULTING ENGINEERS, P.C. 902 Market Street Wilmington, North Carolina 28401 (910) 343-9653 (910) 343-9604 (Fax) License # C-3641 N&T Project No. 16121 sa moA NARRATIVE UNC WILMINGTON - HONORS, INTERNATIONAL, AND PRIVATIZED HOUSING, AND ASSOCIATED PARKING LOT IMPROVEMENTS PHASE 1 (SW8 970128) Receiving Stream Name: Bradley Creek Stream Class: Sc; HQW Stream Index Number: 18-87-24-4-(1) DESCRIPTION: ";FIVE JUL 3 0 2018 BY: The UNCW Allied Health & Human Services Building is located on the Southwest side of the intersection of Walton Drive and Seahawk Village Loop on the campus of UNC- Wilmington in Wilmington, NC. The majority of the proposed building site is currently an existing parking lot. The site was originally developed as the S and T parking lots and the drainage area flows to the existing Price Road Stormwater Pond. The soils of the site consist of sand and silty sands with grades ranging from 1% to 3%. 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 development of the UNCW Allied Health & Human Services Building expands the drainage area to the Price Road Pond (SW8 980427) by 22,576 SF. This area is currently in the drainage area of the stormwater pond permitted under SW8 970128. Therefore, the total drainage area to the SW8 970128 stormwater pond is being reduced by 22,576 SF. To simplify the permitting the impervious surface to the pond remains unchanged from the previous approval. The attached calculations demonstrate that the pond, as built and previously permitted provides the required treatment volume. The required volume is reduced by the reduction of drainage area. Per email correspondence with DEMLR staff (Mrs. Christine Hall) we are submitting for a minor modification to the exiting permit. EROSION CONTROL MEASURES: The attached plans and specifications outline the requirements for erosion control measures. Silt fencing will be provided where stormwater would be expected to sheet flow from disturbed areas directly to adjacent property. Inlet protection will be installed on all inlets within land disturbance prior to construction. 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. Gravel construction entrances will be constructed at three (3) entrances. Maintenance of all erosion control measures will be provided by the grading contractor. E 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 existing detention pond / silt basin will provide erosion control sediment storage. Disturbed areas will be landscaped or seeded upon completion. L= IV E JUL 3 0 20!3 ar:� sl� EROSION CONTROL NOTES AND MAINTENANCE PLAN JUL 3 0 1. All erosion and sediment control measures will be checked for stability and operation following every runoff -producing rainfall, but in no case, less than once every week and within 24 hours of every half -inch rainfall. 2. All points of egress will have construction entrances that will be periodically top - dressed with an additional 2 inches of #4 stone to maintain proper depth. They will be maintained in a condition to prevent mud or sediment from leaving the site. Immediately remove objectionable material spilled washed or tracked onto the construction entrance or roadways. 3. Sediment will be removed from hardware cloth and gravel inlet protection, block and gravel inlet protection, rock doughnut inlet protection and rock pipe inlet protection when the designed storage capacity has been half filled with sediment. Rock will be cleaned or replaced when the sediment pool no longer drains as designed. Debris will be removed from the rock and hardware cloth to allow proper drainage. Silt sacks will be emptied once a week and after every rain event. Sediment will be removed from around beaver dams, dandy sacks and socks once a week and after every rain event. 4. Diversion ditches will be cleaned out immediately to remove sediment or obstructions from the flow area. The diversion ridges will also be repaired. Swales must be temporarily stabilized within 21 calendar days of cease of any phase of activity associated with a swale. 5. Sediment will be removed from behind the sediment fence when it becomes half filled. The sediment fence will be repaired as necessary to maintain a barrier. Stakes must be steel. Stake spacing will be 6 feet max. with the use of extra strength fabric, without wire backing. Stake spacing will be 8 feet max. when standard strength fabric and wire backing are used. If rock filters are designed at low points in the sediment fence, the rock will be repaired or replaced if it becomes half -full of sediment, no longer drains as designed or is damaged. 6. Sediment will be removed from sediment traps when the designed storage capacity has been half filled with sediment. The rock will be cleaned or replaced when the sediment pool no longer drains or when the rock is dislodged. Baffles will be repaired or replaced if they collapse, tear, decompose or become ineffective. They will be replaced promptly. Sediment will be removed when deposits reach half the height of the 1st baffle. Floating skimmers will be inspected and kept clean weekly. 7. Sediment will be removed from the sediment basin when the design storage capacity has been half filled with sediment. Rock will be cleaned or replaced when the sediment pool no longer drains or if the rock is dislodged. Baffles will be repaired or replaced if they collapse, tear, decompose or become ineffective. They will be replaced promptly. Sediment will be removed from baffles when deposits 12 reach half the height of the 1st baffle. Floating skimmers will be inspected weekly and will be kept clean. Land Quality Requires: 8. 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. All slopes will be stabilized within 21 calendar days. All other areas will be stabilized within 15 working days. Water Quality Requires: 9. 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. All perimeter dikes, swales, ditches, perimeter slopes, all slopes steeper than 3' horizontal to 1' vertical (3:1) and all high quality water (HQW) zones shall be provided temporary or permanent stabilization with ground cover as soon as practicable but in any event within seven (7) calendar days from the last land - disturbing activity. All other disturbed areas shall be provided temporary or permanent stabilization with ground cover as soon as practicable but in any event within fourteen (14) calendar days from the last land -disturbing activity. 10. Flocculants will be used to address turbidity issues. The pumps, tanks, hoses and inject systems will be checked for problems or turbid discharges daily. 11. Refer to new NPDES rules regarding basin outlet structures and skimmers shall withdraw water from the surface. ECEIVE JUL 3 0 2013 By:_---- 5 reach half the height of the 15t baffle. Floating skimmers will be inspected weekly and will be kept clean. Land Quality Requires: 8. 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. All slopes will be stabilized within 21 calendar days. All other areas will be stabilized within 15 working days. Water Quality Requires: 9. 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. All perimeter dikes, swales, ditches, perimeter slopes, all slopes steeper than 3' horizontal to 1' vertical (3:1) and all high quality water (HQW) zones shall be provided temporary or permanent stabilization with ground cover as soon as practicable but in any event within seven (7) calendar days from the last land - disturbing activity. All other disturbed areas shall be provided temporary or permanent stabilization with ground cover as soon as practicable but in any event within fourteen (14) calendar days from the last land -disturbing activity. 10. Flocculants will be used to address turbidity issues. The pumps, tanks, hoses and inject systems will be checked for problems or turbid discharges daily. 11. Refer to new NPDES rules regarding basin outlet structures and skimmers shall withdraw water from the surface. ECEQVE JUL 3 0 2013 8y: 5 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, 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 21 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 shall be 20% carpet grass, 24% Bermuda, 20% turf Fescue, 10% Creeping Red Fescue, and 24% Annual Rye grain. 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. 2.7 Silt fence shall consist of NCDOT Class A fabric supported by 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. 0 2019 $V Eh 2.9 Aggregate for construction entrance shall be #4 washed stone. JUL 3 ay - 6 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 offsite 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 seedbeds after planting where required. 1. Apply grain straw and hay at a rate of 75 to 100 pounds per 1,000 square feet and wood chips at a rate of 500 pounds per 1,000 square feet. Jute and mesh should be installed as per manufacturer's instructions. 2. Asphalt emulsion for slope stabilization should be applied at a rate of 1,000 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. Clean silt fence of accumulated sediment after each rainfall event or when it exceeds a depth of 0.5 feet above natural grade. 3.3.3 Stone Check Dams, placed at the discharges of creeks, ditches, and swales, shall consist of Class A or Class B erosion control stone at minimum two feet high and three feet thick across the watercourse, with a one foot thick layer of gravel on upstream side. Remove sediment if accumulated to a depth of 1.0 feet at upstream face. ECEIVE 7 JUL 3 0 2013 BY: 14 Vegetative Cover: Establish and maintain 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 firm, 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 1,000 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. Regrade and seed eroded areas immediately 3.4.3 Mulch all areas immediately after seeding. Mulch shall be applied and anchored as specified hereinbefore. Reapply as necessary to retain cover until grass is established. 3.5 Construction Entrance: Provide an aggregate drive, 20 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. Remove soil if accumulated to a depth greater than 0.5 inches. 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 ECEIVE JUL 3 0 209 BY: r^�--- L-1 902 Market Street Wilmington, NC 28401 (910) 343-9653 (910) 343-9604 Fax John S. Tunstall, P.E. T.Jason Clark, P.E. Joseph S. Hill, Jr., P.E. July 5, 2018 NORMS & TUNSTALL CONSULTING ENGINEERS P.C. I JUL 0 5 2u1 BY: 1429 Ash -Little River Road Ash, NC 28420 (910)287-5900 (910) 287-5902 Fax J. Phillip Norris, P.E. Thomas J. Scheetz, E.I. Ms. Christine Hall, Environmental Engineer NC DEQ Division of Energy, Mineral and Land Resources — State Stormwater Program 127 Cardinal Drive Extension Wilmington, NC 28405-3845 Re: State SW Project No. SW8 980427 (UNCW Price Road Pond) State SW Project No. SW8 970128 (UNC Wilmington — Honors, International, and Privatized Housing, and Associated Parking Lot Improvements Phase 1) UNCW Allied Health & Human Services Building (Package C Update) Wilmington, NC N&T Project No. 16121 Dear Ms. Hall: Pursuant to your comment letter of June 7, 2018, we offer the following responses. 1. Permit Condition 11.11 of both SW8 980427 and SW8 970128: a. The submitted plans show changes from the current grading such that the previously delineated and approved drainage areas are being impacted. Please either: i. Reconsider the proposed grading to preserve the previously approved drainage area; or Response: Due to existing grades and underground utilities, we cannot revise the Grading Plan at this time. ii. If the proposed grading is changing such that the previously approved drainage area / project boundary is being impacted, please submit a major modification for both SW8 980427 and SW8 970128 to document the changes. Response: E�E'IVE JUL 3 0 20113 BY: Per our email communication (June 27, 2018), we are submitting Minor Modifications for both the SW8 980427 and SW8 970128 Permits. The modification is an additional (22,576 SF) to the drainage area for the Price Road Pond in SW8 980427 and a reduction (22,576 SF) from the Ms. Christine Hall / NC DEQ Stormwater f JuLy 5, 2018 Page 2 stormwater pond in SW8 970128. We have provided revised overall Drainage Area Maps for each permit. Also, we are providing revised calculations demonstrating that the ponds, as they were previously permitted, meet the State requirements after this minor modification. The total impervious to each permitted pond remains unchanged from previous permit. Since the proposed total impervious to the SW8 980427 Price Road Pond is being reduced with this development, the reduced amount is now in the Future column. b. The submitted plans show improvements outside of the drainage area / project area approved under SW8 980427. The grassed area along Cahill Drive, between the parking lot entrance and Walton Drive is permitted under SW8 970128. Please submit a modification to SW8 970128 to address the changes within that project area. Response: Please see responses above. 2. 15A NCAC 02H.1042(2)(g)(ii): Please delineate the drainage area / project boundary on the plans. Response: We have provided revised overall Drainage Area Maps for each permit. Enclosed for each of the impacted permits (SW8 980427 and SW8 970128) are two (2) sets (if plans, one (1) set of calculations, one (1) copy of the Stormwater Narrative, two (2) original Stormwater Minor Modification Permit applications, the original revised Supplement EZ form, the original Operation & Maintenance Agreement EZ form, and one (1) CD (plans and application). 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, NORRIS & TUNSTALL CONSU TING ENGINE�E�RS�,�P.C. , T. Jason lark, PE TJC/asn 16121 07-05-18-s-sw-response-Itr (Pkg C Update-SW8 970128) FEC E I V 9 Enclosures t JUL 3 0 209 .y NCBELS License C-3641 Hall, Christine From: Hall, Christine Sent: Wednesday, June 27, 2018 2:18 PM To: 'Jason Clark'; John Tunstall; Amy Norris Subject: RE. [External] Re. request for additional info - SW8 980427 Allied Health Building / Veterans Hall Jason, Thanks for the email. If the pond design themselves are not changing but the only thing changing is the drainage area with its cascading effect on the SA/DA using the criteria in place under the currently approved design, I am willing to handle this as minor mods for both SW8 980427 and 970128. For instance, I know that SW8 970128 was recently expanded and redesigned under 2017 however, SW8 980427 still remains under the previous design criteria. The submittals will still need to provide updated supplements and calculations showing the change, but the rest of the information should remain the same. However, if other changes are needed, it will likely have to be a major modification. Let me know if you have any more questions! Christine Hall Environmental Engineer Division of Energy, Mineral and Land Resources — Stale Stormwaler Program Department of Environmental Quality 910 796 7215 office 910 796 7335 direct chnshne hall@ncdenr gov 127 Cardinal Drive Ext Wilmington, NC 28405 5>- Nothing Compares n Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties. From: Jason Clark [mailto:jclark@ntengineers.com] Sent: Wednesday, June 27, 2018 8:18 AM To: Hall, Christine <Christine,HaII@ncdenr.gov>; John Tunstall <junstall@ntengineers.com>; Amy Norris <a norris@ ntengineers.com> Subject: [External] Re: request for additional info - SW8 980427 Allied Health Building / Veterans Hall Christine, I'm working on these issues. Can I ask a few questions on how I should handle this? The plans are to the point where we can't change the grading at this time. I see that two drainage areas are impacted, SW8 980427 and SW8 970128. The Allied Health Permit, to Price Road Pond SW8 980427, expands the drainage are of the pond by 22,576 sf. This same amount is being removed from the pond DA of SW8 970128. Our Plan reduces the amount of impervious proposed, SW8 980427. The amount reduced will be placed in Future column. The pond as sized can easily treat, the additional 22,576 sf of new DA. Since there is no increase in impervious the additional volume is only 142 cf. Is there any way this minor revision can be handled as a minor modification? If not I will demonstrate that the pond as is provides more than enough storage volume, meets 2017 SA/DA and the orifice as is still works. As noted above, the DA to the SW8 970128 is being reduced by 22, 576 sf. For simplicity the BUA to this permitted pond will remain the same. There are many iterations of calculations for this pond due to dates of development, many at 1" and many at 1.5 inches. The reduction in required volume is calculated to be 142 cf, 22,576 sf at 1.5 inch of runoff The required volume goes down and the remaining aspects of the pond remain unchanged. Is there any way to treat this revision as a minor modification? If not I will show the reduction of DA and the reduction of required volume and show that the remaining parts of the application and supplement will remain unchanged. Please advise on the above. Thanks for your help, T. Jason Clark. PE NORMS &TVNSTALL CONSUC]"IrNG ENGINEERS P.C. 902 Market Street, Wilmington, NC 28401 910-343-9653 (Ext 202) 1 910-343-9604 (F) iclark(a)ntengineers.com It is the professional opinion of Norris & Tunstall Consulting Engineers, P C. and Norris, Kuske & Tunstall Consulting Engineers, Inc. that this electronic information provides design information current as of the date of its release It shall be the responsibility of the party receiving the data to examine it to see that it contains the necessary files and information requested. In transferring the files in electronic media format, Norris & Tunstall Consulting Engineers, P.C. and Norris, Kuske & Tunstall Consulting Engineers, Inc. makes no representations as to the usability or readability of documents resulting from the use of software application packages, operating systems, or computer hardware differing from those used by Norris & Tunstall Consulting Engineers, P C. and Norris, Kuske & Tunstall Consulting Engineers, Inc. in the preparation of such data. From: Christine Hall <christine.hall@ncdenr.gov> Date: Thursday, June 7, 2018 at 11:37 AM To: Jason Clark <iclark@ntengineers.com>, John Tunstall <jtunstall@ntengineers.com>, Amy Norris <anorris@ntengineers.com>, Mark Morgan <morganm@uncw.edu> Subject: request for additional info - SW8 980427 Allied Health Building / Veterans Hall Gentlemen, Attached is a pdf of the request for additional information for the subject protect. This will be the only copy that you will receive. Please let me know if you have any questions or concerns. Thanks. Christine Hall Environmental Engineer Division of Energy. Mineral and Land Resources — State Stormwater Program Department of Environmental Quality 910 796 7215 office 910 796 7335 direct christine hall(a),ncdenr.00v 127 Cardinal Drive Ext Wilmington, NC 28405 a: !—'Nothing Compares,.. Email correspondence to and from this address is subject to the North Carolina Public Records Law and may be disclosed to third parties.