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SW8091113_HISTORICAL FILE_20120615
STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW8 Q)c� �� \3 DOC TYPE ❑ CURRENT PERMIT ❑ APPROVED PLANS © HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE 2012 0l,o 15 YYYYMMDD North Carolina Beverly Eaves Perdue Governor June 15, 2012 'A NC®ENR Department of Environment and Division of Water Quality Charles Wakild, P. E. Director Commanding Officer, MCB Camp Lejeune c/o Carl Baker, P.E., Deputy Public Works Officer Building 1005 Michael Road Camp Lejeune, NC 28547 Natural Resources Dee Freeman Secretary Subject: State Stormwater Management Permit No. SW8 091113 Mod. P688 Apron Expansion Phase II, P683/P687 MV-22 Hangar Development and POV Parking Garage High Density Commercial infiltration Basin and Sand Filter Project Onslow County Dear Mr. Baker: The Wilmington Regional Office of the Division of Water Quality received a complete, modified State Stormwater Management Permit Application for P688, Apron Expansion Phase II, P683 / P687 MV-22 Hangar Development and POV Parking Garage on June 12, 2012. Staff review of the plans and specifications has determined that the project, as proposed, will comply with the Stormwater Regulations set forth in Session Law 2008-211 and Title 15A NCAC 2H.1000. We are forwarding modified Permit No. SW8 091113 dated June 15, 2012, for the construction, operation and maintenance of the built -upon areas and BMP's associated with the subject project. This following modifications are included in this permit: 1. Combines the two previously permitted separate hangar buildings P683 and P687 into one larger hangar, MV-22. An additional BMP (Rainwater Harvesting System) was added within the existing IB-1 drainage area to collect the runoff from 110,000 sf of the MV-22 roof area, reuse it as airplane washdown water and bypass any overflow to I13-1. Because the RHS tank only holds 80,000 gallons, the net roof impervious area gain for IB-1 is 34,960 square feet. 2. Adds a POV (privately owned vehicle) parking garage to accommodate 1254 vehicles, with runoff treated in 4 new sand filters. 3. The P688 Apron Expansion and existing Infiltration Basin #1 (IB-1) are unchanged from the April 2010 permit, although the allocated total BUA has been broken down into its component parts. The combined hangar has resulted in 228,260 square feet of BUA directed into the existing infiltration basin. The future allocation for IB-1 under the April 2010 permit was 268,050 square feet, thus leaving 39,790 square feet available for future development in IB-1. On August 5, 2009, the Governor signed Session Law 2009-406. This law impacts any development approval issued by the Division of Water Quality under Article 21 of Chapter 143 of the General Statutes, which is current and valid at any point between January 1, 2008, and December 31, 2010, The law extends the effective period of any stormwater permit that is set to expire during this time frame to three (3) years from its current expiration date. On August 2, 2010, the Governor signed Session Law 2010-177, which grants an extra year for a total potential of four (4) years extension. Please note that the expiration date of this permit, January 1, 2022, has been adjusted to reflect this extension. This permit shall be effective from the date of issuance until January 1, 2022, and shall be 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), certification of the BMP's, 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 certify the BMP's, to transfer the permit, or to renew the permit, will result in future compliance problems. Wilmington Regional Office 127 Cardinal Drive Extension, Wilmington, North Carolina 28405. One Phone: 910-796-72151 FAX: 910-350-20041 DENR Assistance: 1-877-623-6748 NOrthCarolina Internet: \ .ncwaterquality.org Najinna//ff An Eoual O000rlunity \ ARrmalive Action Emolover State Stormwater Management Systems Permit No. SW8 091113 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 150E 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, or need additional information concerning this matter, please contact Linda Lewis at (910) 796-7301. Since ly, k" Charles akiW Id, %PE.., Director Division of Water Quality GDS/arl: S:\WQS\Stormwater\Permits & Projects\2009\091113 HD\2012 06 permit 091113 cc: Travis Lumen, P.E., Haskell Architects & Engineers Wilmington Regional Office Stormwater File Page 2 of 9 State Stormwater Management Systems Permit No. SW8 091113 STATE OF NORTH CAROLINA DEPARTMENT OF ENVIRONMENT AND NATURAL RESOURCES DIVISION OF WATER QUALITY STATE STORMWATER MANAGEMENT PERMIT HIGH DENSITY COMMERCIAL 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 Commanding Officer US Marine Corps Base Camp Lejeune P688 Apron Expansion Phase 11, P683IP687 MV-22 Hangar and POV Parking Garage Curtis Road, Camp Lejeune, Jacksonville, Onslow County FOR THE construction, operation and maintenance of one (1) infiltration basin and four (4) sand filters in compliance with the provisions of Session Law 2008-211 and 15A NCAC 2H .1000 (hereafter collectively and separately referred to as the "stormwater rules') and the approved stormwater management plans and specifications and other supporting data as attached and on file with and approved by the Division of Water Quality and considered a part of this permit. This permit shall be effective from the date of issuance until January 1, 2022, 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 Sections 1.9, 1.10 and 1.11 of this permit. The stormwater controls labeled IB-1, SF-1, SF-2, SF-3, SF-4 and RHS have been designed to handle the runoff from 2,439,933 sf; 53,815 sf; 81,260 sf; 115,730 sf; 76,267 sf; and 71,290 sf of built -upon area, respectively. Infiltration Basin IB-1 has 39,790 square feet of future allocation available. 3. The infiltration basin IB-1 must be operated with a 50 foot vegetated filter, designed to pass the peak flow from the 10 year storm in a diffuse and non -erosive manner. The four sand filters are not required to be operated with a vegetated filter. 4. The RHS tank will collect the runoff from 110,000 sf of the MV-22 roof area, reuse it as airplane washdown water and bypass any overflows to I8-1. Because the RHS tank only holds 80,000 gallons, the net volume of the roof impervious area that can be stored in the RHS tank is 10,695 cubic feet which results in an impervious area of 71,290 square feet. 5. The drainage area of each BMP will be limited to the amount of built -upon area indicated in Sections 1.9, 1.10 and 1.11 of this permit, and as shown on the approved plans. 6. 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. 7. The runoff from all built -upon area within the permitted drainage areas of this project must be directed into the permitted stormwater control system. Page 3 of 9 State Stormwater Management Systems Permit No. SW8 091113 8. The project shall provide a 50 foot wide vegetated buffer adjacent all surface waters, measured horizontally from and perpendicular to the normal water line of impounded structures, the top of bank of both sides of streams and rivers, and the mean high water line of tidal waters. No built -upon area is allowed in the buffer. 9. The following design criteria have been permitted for the proposed sand filters and must be provided and maintained at design condition: Desi n Criteria Units SF-1 SF-2 SF-3 SF- 4 SF # 1. Drainage Area Onsite Offsite acres Ft Ft2 1.90 82.905 0 4.88 212,500 0 4.50 196,000 0 3.78 164,785 0 2. Total Impervious Surfaces (1) Buildings (2) Roads (3) Parking (4) Sidewalks (5) Other 6 Future Ft 53,815 0 31,516 22,299 0 0 0 81,260 0 75.907 648 4,440 265 1 0 115,730 105,460 10,270 0 0 0 0 76,267 0 70,142 0 5,860 265 0 3. 2008 Design Storm Inches 1.5 1.5 1.5 1.5 4. Sediment Chamber Depth Feet 4.5 3.0 3.0 3.0 5. Sand Chamber Depth Feet 4.5 7.0 5.5 4.5 6. Sed. Chamber Bottom Elev. fmsl 12.5 10.0 12.0 10.0 7. Sand Chamber Bottom Elev. fmsl 12.5 6.0 9.5 8.5 8. Sed. Chamber Surface Area Ft 850 750 1,350 1,250 9. Sand Chamber Surface Area Ft 800 700 1,350 1,250 10. Sed. Chamber Weir Elev. fmsl 14.0 13.0 15 13 11: Top of Sand Elevation fmsl 14.0 7.5 11.0 10.0 12. Maximum Head on Filter Feet 3 5.5 4 3 13. Offline Bypass Weir Elev. fmsl 17.07 14.08 15.1 13.17 14. Permitted Storage Volume Ft 4,950 14,384 16,459 10,765 15. Underdrain Diameter Inches 6 6 6 6 16. Number of underdrains ea 1 4 3 3 17. Time to Draw Down hours <40 <40 <40 <40 18. SHWT Elevation fmsl 10.0 5.0 1 8.0 7.0 19. Receiving Stream New River 20. Stream Index Number WOK02 19- 11 21. Stream Classification SC HQW NSW 10. The following design criteria have been permitted for the Rainwater Harvesting System, RHS, and must be provided and maintained at design condition: a. Captured Roof Area, ft2: 110,000 b. 2008 Design Storm, inches: 1.5 C. Permitted Storage Volume, ft3: 10,694 d. Net Effective captured roof area, ft2: 71,290 (Overflow is directed to IB-1) e. Dedicated Use: Washdown water for planes (An estimated 57,600 gallons (7,700 ft) per week is needed for this dedicated use.) Page 4 of 9 State Stormwater Management Systems Permit No. SW8 091113 11. The following design criteria have been permitted for the existing infiltration basin IB-1 and must be provided and maintained at design condition: a. Drainage Area, acres: Onsite, ft2: Offsite, ft2: b. Total Impervious Surfaces, ft2: Apron, ft2: Taxiway, ft2: MV-22 Hangar, ft2: Future, ft2: C. 2008 Design Storm, inches: d. Basin Depth, feet: e. Bottom Elevation, FMSL: f. Bottom Surface Area, ft2: g. Bypass Weir Elevation, FMSL: h. Permitted Storage Volume, ft3: i. Type of Soil: j. Expected Infiltration Rate, in/hr: k. Seasonal High Water Table, FMSL: I. Time to Draw Down, hours: M. Receiving Stream/River Basin: n. Stream Index Number: o. Classification of Water Body: II. SCHEDULE OF COMPLIANCE 59.41 2,587,759 0 2,439,933 2,082,465 172,718 144,960 (includes 34,960 from RHS overflow) 39,790 1.5 6.0 11.0 160,218 12.8 291,198 sand 5.0 9.0 5.0 New River / WOK02 19-(11) "SC:HQW:NSvv 1. The stormwater management system shall be constructed in its entirety, vegetated and operational for its intended use prior to the construction of any built -upon surface. 2. During construction, erosion shall be kept to a minimum and any eroded areas of the system will be repaired immediately. 3. The permittee shall at all times provide the operation and maintenance necessary to assure the permitted stormwater system functions at optimum efficiency. The approved Operation and Maintenance Plan must be followed in its entirety and maintenance must occur at the scheduled intervals including, but not limited to: a. Semiannual scheduled inspections (every 6 months). b. Sediment removal. C. Mowing and re -vegetation of slopes and the vegetated filter. d. Immediate repair of eroded areas. e. Maintenance of all slopes in accordance with approved plans and specifications. f. Debris removal and unclogging of bypass structure,.infiltration media, flow spreader, catch basins, piping and vegetated filter. g. A clear access path to the bypass structure must be available at all times. 4. The facilities shall be constructed as shown on the approved plans. This permit shall become void unless the facilities are constructed in accordance with the conditions of this permit, the approved plans and specifications, and other supporting data. 5. 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. 6. A copy of the approved plans and specifications shall be maintained on file by the Permittee for a minimum of ten years from the date of the completion of construction. 7. Records of maintenance activities must be kept for each permitted BMP. The reports will indicate the date, activity, name of person performing the work and what actions were taken. Page 5 of 9 State Stormwater Management Systems Permit No. SW8 091113 8. 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. 9. The permittee shall submit to the Director and shall have received approval for revised plans, specifications, and calculations prior to construction, for any modification to the approved plans, including, but not limited to, those listed below: a. Any revision to any item shown on the approved plans, including the stormwater management measures, built -upon area, details, etc. b. Redesign or addition to the approved amount of built -upon area or to the drainage area. C. Further development, subdivision, acquisition, lease or sale of any, all or part of the project area. d. Any alteration to any pipe or any vegetative conveyance shown on the approved plan. e. The construction of any allocated future built -upon area within the permitted drainage area. 10. The Director may notify the permittee when the permitted site does not meet one or more of the minimum requirements of the permit. Within the time frame specified in the notice, the permittee shall submit a written time schedule to the Director for modifying the site to meet minimum requirements. The permittee shall provide copies of revised plans and certification in writing to the Director that the changes have been made. III. GENERAL CONDITIONS 1. Approved plans and specifications for this project are incorporated by reference and are enforceable parts of the permit. 2. This permit is not transferable to any person or entity except after notice to and approval by the Director. At least 30 days prior to a change of ownership, or a name change of the owner or of the project, or a mailing address change, the permittee must submit a completed and signed Name/Ownership Change form to the Division of Water Quality, accompanied by the appropriate documentation as listed on the form. The approval of this request will be considered on its merits and may or may not be approved. 3. The permittee is responsible for compliance with all permit conditions until such time as the Division approves the transfer request. 4. Any individual or entity found to be in noncompliance with the provisions of this stormwater management permit or the stormwater rules, is subject to the enforcement procedures as set forth in Article 21, Chapter 143 of the North Carolina General Statutes. 5. The issuance of this permit does not preclude the Permittee from complying with any and all statutes, rules, regulations, or ordinances, which may be imposed by other government agencies (local, state, and federal) having jurisdiction. 6. In the event that the facilities fail to perform satisfactorily, including the creation of nuisance conditions, the Permittee shall take immediate corrective action, including those as may be required by this Division, such as the construction of additional or replacement stormwater management systems. 7. The permittee grants DENR Staff permission to enter the property during normal business hours for the purpose of inspecting all components of the permitted stormwater management facility. Page 6 of 9 State Stormwater Management Systems Permit No. SW8 091113 8. The permit issued shall continue in force and effect until revoked or terminated. The permit may be modified, revoked and reissued or terminated for cause. The filing of a request for a permit modification, revocation and re -issuance or termination does not stay any permit condition. 9. Unless specified elsewhere, permanent seeding requirements for the stormwater controls must follow the guidelines established in the North Carolina Erosion and Sediment Control Planning and Design Manual. 10. 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 as allowed by the laws, rules and regulations contained in Session Law 2008-211, Title 15A NCAC 2H.1000, and NCGS 143-215.1 et. al. 11. The permittee shall submit a permit renewal application at least 180 days prior to the expiration date of this permit. The renewal request must include the appropriate documentation and the processing fee. Permit modified and reissued this the 15th day of June 2012. NORTH CAROLINA ENVIRONMENTAL MANAGEMENT COMMISSION Q Charles kild, A�1—irector Division of Water Quality By Authority of the Environmental Management Commission Page 7 of 9 State Stormwater Management Systems Permit No. SW8 091113 P688 Apron Expansion„ P683/P687 MV-22 Hangar Development and POV Parking Garage Stormwater Permit No. SW8 0911.13 MCAS Camp Leieune Onslow County Page 1 of 2 Designer's Certification I, , as a duly registered in the State of North Carolina, having been authorized to observe (periodically/ weekly/ full time) the construction of the project, for (Project Owner) hereby state that, to the best of my abilities, due care and diligence was used in the observation of the project construction such that the construction was observed to be built within substantial compliance and intent of the approved plans and specifications. The checklist of items on page 2 of this form is included in the Certification. Noted deviations from approved plans and specification: Signature Registration Number Date SEAL Page 8 of 9 State Stormwater Management Systems. Permit No. SW8 091113 Certification Requirements: Page 2 of 2 1. The drainage area to the system contains approximately the permitted acreage. 2. The drainage area to the system contains no more than the permitted amount of built -upon area. 3. All the built -upon area associated with the project is graded such that the runoff drains to the system. 4. All roof drains are located such that the runoff is directed into the system. 5. The bypass structure weir elevation is per the approved plan. 6.• The bypass structure is located per the approved plans. 7. A Trash Rack is provided on the bypass structure. 8. All slopes are grassed with permanent vegetation. 9. Vegetated slopes are no steeper than 3:1. 10. The inlets are located per the approved plans and do not cause short-circuiting of the system. 11. The permitted amounts of surface area and/or volume have been provided. 12. All required design depths are provided. 13. All required parts of the system are provided. 14. The required system dimensions are provided per the approved plans. cc: NCDENR-DWQ Regional Office Page 9 of 9 - DWQ USE ONLY Date Received Fee Paid Permit Number 5- - oi� Applicable Rules: (select all that apply) ❑Coastal SW - 1995 ❑ Coastal SW - 2008 ❑ Ph II - Post onstruction ❑ Non -Coastal SW- FIQW/ORW Waters ❑ Universal Stormwater Management Plan ❑ Other WQ M mt Plan: State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM This form may be photocopied for use as an original I. GENERAL INFORMATION 1. Project Name (subdivision, facility, or establishment name - should be consistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): MCAS New River P-683 / P-687 MV-22 Hangar Development 2. Location of Project (street address): Longstaff Street between Curtis Road and Perimeter Street City:iacksonville County:Onslow Zip:28545 3. Directions to project (from nearest major intersection): From U.S. 17 and Curtis Road travel East on Curtis Road then South on Longstaff Street 4. Latitude:34° 42' 7" N Longitude:77° 25' 51" W of the main entrance to the project. II. PERMIT INFORMATION: 1. a. Specify whether project is (check one): [-]New ®Modification b.If this application is being submitted as the result of a modification to an existing permit, list the existing permit nomnberSW8 091113 , its issue date (if known)4/13/2010 , and the status of construction: ®Not Started ❑Partially Completed* ❑ Completed* *provide a designer's certification 2. Specify the type of project (check one): ❑Low Density ®High Density ❑Drains to an Offsite Stormwater System []Other 3. If this application is being submitted as the result of a previously returned application or a letter from DWQ requesting a state stormwater management permit application, list the stormwater project number, if assigned, N/A and the previous name of the project, if different than currently proposed, N/A 4. a. Additional Project Requirements (check applicable blanks; information on required state permits can be obtained by contacting the Customer Service Center at 1-877-623-6748): ❑LAMA Major ®Sedimentation/Erosion Control: 90.73 ac of Disturbed Area ❑NPDES Industrial Stormwater E404/401 Permit: Proposed Impacts b.If any of these permits have already been acquired please provide the Project Name, Project/Permit Number, issue date and the type of each permit: ESC and Wetland permits not yet acquired Federal Consistency for CAMA will also be applied for. :CIEI V Eb ' MAY 0 4 2012 z BY: FormSWU-101 Version07Jun2010 Page I of III. CONTACT INFORMATION 1. a. Print Applicant / Signing Official's name and title (specifically the developer, property owner, lessee, designated government official, individual, etc. who owns the project): Applicant/Organization: Commanding Officer, Marine Corps Base Camp Lejeune Signing Official & Title:Carl H. Baker, P.E., Deputy Public Works Officer b.Contact information for person listed in item la above: Street Address:13uilding 1005 Michael Road City:MCB Camp Lejeune State:NC Zip:28547 Mailing Address (if applicable): City: Phone: (910 ) 451-2213 Email:carl.h.baker@usmc.mil Fax: (910 ) 451-2927 c. Please check the appropriate box. The applicant listed above is: ® The property owner (Skip to Contact Information, item 3a) ❑ Lessee* (Attach a copy of the lease agreement and complete Contact Information, item 2a and 2b below) ❑ Purchaser* (Attach a copy of the pending sales agreement and complete Contact Information, item 2a and 2b below) ❑ Developer* (Complete Contact Information, item 2a and 2b below.) 2. a. Print Property Owner's name and title below, if you are the lessee, purchaser or developer. (This is the person who owns the property that the project is located on): Property Signing Official & b.Contact information for person listed in item 2a above: Street Address: Mailing Address (if City: Phone: ( ) State: Fax: U 3. a. (Optional) Print the name and title of another contact such as the projects construction supervisor or other person who can answer questions about the project: CEIVE Other Contact Person/Organization Signing Official & Title:Civil Design Branch by: b.Contact information for person listed in item 3a above: Mailing Address:Public Works Division, Bldg 1005 Michael Road City:Camp Lejeune State:NC Zip:28547 Form SWU-101 Version 07Jun2010 Page 2 of 7 Phase: (910 ) 451-3238, ext. 3284 Fax: Emaibdavid.towler©usns.mil 4. Local jurisdiction for building permits: Point of IV. PROJECT INFORMATION Phone #: 1. In the space provided below, briefly summarize how the stormwater runoff will be treated. The majority of the new Hangar will drain to and be treated by the facility permitted under No. SW8 091113. The remainder of the new Hangar will be collected and treated by a new Rainwater Harvesting System (RHS) for a dedicated vear-round use of washing the MV-22's 7'he surrounding developed area, including the entire parking garage, will be treated via closed sand filter BMP's Pre-treatment will occur through sedimentation chambers/basins. Flows in excess of the 10-vear/24-liour storm will bypass these systems via overflow weirs incorporated in the sand filter chamber/basin design. 2. a. ff claiming vested rights, identify the supporting documents provided and the date they were approved: ❑ Approval of a Site Specific Development Plan or PUD Approval Date: ❑ Valid Building Permit Issued Date: ❑ Other: Date: b. ff claiming vested rights, identify the regulation(s) the project has been designed in accordance with: ❑ Coastal SW -1995 ❑ Ph II - Post Construction 3. Stormwater runoff from this project drains to the White Oak River basin. 4. Total Property Area: 24.34 acres 5. Total Coastal Wetlands Area: 0.00 acres 6. Total Surface Water Area: 0.00 acres 7. Total Property Area (4) - Total Coastal Wetlands Area (5) -Total Surface Water Area (6) = Total Project Area+:24.34 acres Total project area shall be calculated to exclude the following the normal pool of impounded structures, the area between the banks of streams and rivers, the area below the Normal High Water (NHW) line or Mean High Water (MHW) line, and coastal wetlands landward from the NHW (or MHW) line. The resultant project area is used to calculate overall percent built upon area (BUA). Non -coastal wetlands larndward of the NHW (or MHW) line nay be included in the total project area. 8. Project percent of impervious area: (Total Impervious Area / Total Project Area) X 100=12.99/24.34 = 53.4 % 9. How many drainage areas does the project have? 7 (For high density, count 1 for each proposed engineered stornnoater BMP. For low densihj and other projects, use I for the whole property area) 10. Complete the following information for each drainage area identified in Project Information item 9. If there are more than four drainage areas in the project, attach an additional sheet with the information for each area provided in the same format as below. ECEIVE MAY 0 4 2012 Form SWU-101 Version 07Jun2010 Page 3 of Basin Information Drainage Area 1 Drainage Area 2 Drainage Area 3 Drainage Area 4 Receiving Stream Name New River New River New River New River Stream Class * SC; NSW SC; NSW SC; NSW SC; NSW Stream Index Number * 19-(H) 19-(11) 19-(11) 19-(11) Total Drainage Area (so 82,905 212,500 196,000 164,785 On -site Drainage Area (so 82,905 212,500 196,000 164,785 Off -site Drainage Area (sf) 0 0 0 0 Proposed Impervious Area** (so 53,815 81,260 115,730 76,267 Impervious Area** total 64.9 38.2 59.0 46.3 Impervious** Surface Area Drainage Area 1 Drainage Area 2 Drainage Area 3 Drainage Area 4 On -site Buildings/Lots (sf) 0 0 105,460 0 On -site Streets (so 31,516 75,907 10,270 70,142 On -site Parking (so 22,299 648 0 0 On -site Sidewalks (so 0 4,440 0 5,860 Other on -site (so 0 265 0 265 Future (so 0 0 0 0 Off -site (so 0 0 0 0 Existing BUA*** (sf) 0 0 0 0 Total (so: 53,815 81,260 115,730 76,267 Stream Class and Index Number call be determined at: 6ttp://portal.nedenr.org web/zoq[ps/esn/classifrrntions Impervious area is defined as the built upon area including, but not lirrdted to, buildings, roads, parking areas, sidewalks, gravel areas, etc. Report only that amount of existing BUA that will remain after development. Do not report ally existing BUA that is to be removed and which will be replaced by new BUA. 11. How was the off -site impervious area listed above determined? Provide documentation. N/A Protects in Union County: Contact DWQ Central Office slaj) to check if the project is located witllin a Threatened & Endangered Species watershed that may be subject to more stringent stormwaler requirements as per NCAC 02B .0600. V. SUPPLEMENT AND O&M FORMS The applicable state stormwater management permit supplement and operation and maintenance (O&M) forms must be submitted for each BMP specified for this project. The latest versions of the forms can be downloaded from http://portal.ticdenr.org/web/wq/ws/su/bop-manual. VI. SUBMITTAL REQUIREMENTS Only complete application packages will be accepted and reviewed by the Division of Water Quality (DWQ). A complete package includes all of the: items listed below. A detailed application instruction sheet and BMP checklists are available from htt : ortal.ncdenr.org/web/wq/ws/su/statesw/forms docs. Thecomplete application package should be submitted to the appropriate DWQ Office. (The appropriate office may be found by locating project on the interactive online map at http://portal.ncdenr.org/web/wq/ws/su/maps.) Please indicate that the following required information have been provided by initialing in the space provided for each item. All original documents MUST be signed and initialed in blue ink. Download the latest versions for each submitted application package fromhttp://portaimcdennorg/web/wg/ws/su/statesw/forms docs. Initials 1. Original and one copy of the Stormwater Management Permit Application Form. 2. Original and one copy of the signed and notarized Deed Restrictions & Protective Covenants /V<% Form. (if required as per Part VII below) 3. Original of the applicable Supplement Form(s) (sealed, signed and dated) and O&M agreement(s) for each BMP. I E 4. Permit application processing fee of $505 payable to NCDE (For an Express rev refer to http://www.envhelp.org/pages/onestopexpress.html for fort, Yoyyiw Ex s program OM and the associated fees. Contact the appropriate regional ficeExpreS's �'ed l5l{t C dinator for additional information and to schedule the required appfi lion meeting.) Form SWU-101 Version 07Jun2010 Page 4 of 7 4s n 1s+riaA_ ,� xyiFy 3x*'� i Basmal'ntoW ion$ ."y. .i ..Q b ,,Existing (I },��, by . . ....; .. RHOS ;Redevelopments r Receiving Stream Name New River New River New River Stream Class SC; NSW SC; NSW SC; NSW Stream Index Number 19-(11) 19-(11) 19-(11) Total Drainage Area (sf) 2,587,759 110,000 183,860 On -site Drainage Area (sf) 2,587,759 75,040 183,860 Off -site Drainage Area (sf) 0 34,960 0 Proposed Impervious Area (sf) 2,439,933 110,000 1 18,280 Impervious Area (total) 94.3% 100.0% 1 I"m,"'pervious' Surface -'A er a f ,r�' *�aE-zi`stin ,(IyB,)" _ f2HS t ; Redevelopment On -site Building / Lots (sf) 110,000 71,290 0 On -site Streets (sf) 172,718 0 18,280 On -site Parking (sf) 2,082,465 0 0 On -site Sidewalks (sf) 0 0 0 Other on -site (sf) (RHS 34,960 0 0 Future (sf) 39,790 0 0 Off -site (sf) 0 0 0 Existing BUA (sf) 0 0 0 Total (sf) 2'•,""439 933 • ° 741"290 8�280 To be noted for the "Existing Infiltration Basin (I-B):" A "Future" BUA amount of 268,050 ft2 was included for the Hangar and the 50' access apron, per Permit SW8 091113. The amount of that future allocation used in this project's developed conditions is 228,260 ft2. This amount includes 110.000 ft2 of Hangar roof drainage directly discharged to the apron trench drain system, an additional 34,960 ft2 of Hangar roof drainage bypassed through the Rainwater Harvesting System (RHS) overflow, and 83,300 ft2 of the 50' access apron. Being that the total is less than what the infiltration basin was designed to treat, there is 39,790 ft2 allocated for future BUA that may be routed to the infiltration basin. JUN l 2 ZU12 ,., M3 5wI�(i( ___ _- 3 Mi 5. A detailed narrative (one to two pages) describing the stormwater treatment/managementfor the project. This is required in addition to the brief summary provided in the Project Information, item 1. 6. A USGS map identifying the site location. If the receiving stream is reported as class SA or the r� receiving stream drains to class SA waters within'h mile of the site boundary, include the 1/2 mile radius on the map. 7. Sealed, signed and dated calculations. 8. Two sets of plans folded to 8.5" x 14" (sealed, signed, & dated), including:_ a. Development/Project name. b. Engineer and firm. c. Location map with named streets and NCSR numbers. d. Legend. e. North arrow. I. Scale. g. Revision number and dates. h. Identify all surface waters on the plans by delineating the normal pool elevation of impounded structures, the banks of streams and rivers, the MHW or NHW line of tidal waters, and any coastal wetlands landward of the MHW or NHW lines. • Delineate the vegetated buffer landward from the normal pool elevation of impounded structures, the banks of streams or rivers, and the MHW (or NHW) of tidal waters. i. Dimensioned property/project boundary with bearings & distances. j. Site Layout with all BUA identified and dimensioned. k. Existing contours, proposed contours, spot elevations, finished floor elevations. 1. Details of roads, drainage features, collection systems, and stormwater control measures. m. Wetlands delineated, or a note on the plans that none exist. (Must be delineated by a qualified person. Provide documentation of qualifications and identify the person who made the determination on the plans. n. Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations. o. Drainage areas delineated (included in the main set of plans, not as a separate document). p. Vegetated buffers (where required). 9. Copy of any applicable soils report with the associated SFIWT elevations (Please identify elevations in addition to depths) as well as a map of the boring locations with the existing elevations and boring logs. Include an 8.5"Al" copy of the NRCS County Soils map with the project area clearly delineated. For projects with infiltration BMPs, the report should also include the soil type, expected infiltration rate, and the method of determining the infiltration rate. (Infiltration Devices submitted to WiRO: Schedule a site visit for DWQ to verify the SHWT prior to submittal, (910) 796-7378.) 10. A copy of the most current property deed. Deed book: N/A Page No: N/A AI� 11. For corporations and limited liability corporations (LLC): Provide documentation from the NC Secretary of State or other official documentation, which supports the titles and positions held by the persons listed in Contact Information, item 1a, 2a, and/or 3a per NCAC 21-1.1003(e). The corporation or LLC must be listed as an active corporation in good standing with the NC Secretary of State, otherwise the application will be returned. http:/ /www.secretary.state.nc.us/Corporations/CSearcli.aspxx VII. DEED RESTRICTIONS AND PROTECTIVE COVENANTS For all subdivisions, outparcels, and future development, the appropriate property restrictions and protective covenants are required to be recorded prior to the sale of any lot. If lot sizes vary significantly or the proposed BUA allocations vary, a table listing each lot number, lot size, and the allowable built -upon area must be provided as an attachment to the completed and notarized deed restriction form. The appropriate deed restrictions and protective covenants forms can be downloaded from http://portaimcdennorg/web/wg/ws/su/statesw/forms does. Download the latest versions for each submittal. In the instances where the applicant is different than the property owner, it is the responsibility of the property owner to sign the deed restrictions and protective covenants form while the applicant is responsible for ensuring that the deed restrictions are recorded. By the notarized signature(s) below, the permit holder(s) certify that the recorded property restrictions and protective covenants for this project, if required, shall include all the items required in the permit and listed on the forms available on the website, that the covenants will be binding on all parties and peerson Qkning under them, that they will run with the land, that the required covenants canno 1 I c j without concurrence from the NC DWQ and that they will be recorded prior to sale of any lot. MAY 0 4 2012 Form SWU-101 Version 07Jun2010 Page 5 of BY: VIII. CONSULTANT INFORMATION AND AUTHORIZATION Applicant: Complete this section if you wish to clesignate authority to another individual and/or firm (such as a consulting engineer and/or firm) so that they may provide information on your behalf for this project (such as addressing requests for additional information). Consulting Engineer:Myra W. Tones, P.E., LEED AP Consulting Firm: Haskell Architects and Engineers, Sr. Civil Engineer Mailing Address:111 City: Jacksonville Phone: (904 ) 791-4666 Email: myra jones@haskell.com State:FL Zip:32202 Fax: (904 ) 475-7887 IX PROPERTY OWNER AUTHORIZATION (if Contact Information, item 2 has been filled ollt, complete this section) 1, (print or type name of person lister! in Contact lrtfornation, item 2a) certify that I own the property identified in this permit application, and thus give permission to (print or hype none of person lister! inn Contact Information, itent 1o) with (print or type name of organization listed in Contact Information, item Ia) to develop the project as currently proposed. A copy of the lease agreement or pending property sales contract has been provided with the submittal, which indicates the party responsible for the operation and maintenance of the stormwater system. As the legal property owner I acknowledge, understand, and agree by my signature below, that if my designated agent (entity listed in Contact Information, item 1) dissolves their company and/or cancels or defaults on their lease agreement, or pending sale, responsibility for compliance with the DWQ Stormwater permit reverts back to me, the property owner. As the property owner, it is my responsibility to notify DWQ immediately and submit a completed Name/Ownership Change Form within 30 days; otherwise I will be operating a stormwater treatment facility without a valid permit. I understand that the operation of a stormwater treatment facility without a valid permit is a violation of NC General Statue 143-215.1 and may result in appropriate enforcement action including the assessment of civil penalties of up to $25,000 per day, pursuant to NCGS 143-215.6. Signature: a Notary Public for the State of do hereby certify that before the this — day of County of personally appeared and acknowledge the due execution of the application for a stormwater permit. Witness my hand and official seal, 4=11 My commission ECEIVE MAY 0 4 2012 BY:__ Form SWU-101 Version 07Jun2010 Page 6 of 7 X. APPLICANT'S CERTIFICATION I, (print or type name of person listed in Contact Information, item 1a) Carl H. Baker certify that the information included on this permit application form is, to the best of my knowledge, correct and that the project will be constructed in conformance with the approved plans, that the required deed restrictions and protective covenants will be recorded, and that the proposed project complies with the requirements of the applicable stor ater rules under A NCAC 2H .1000, SL 2006-246 (Ph. II - Post Construction) or SL 2008-211. Signature:[ Date: I, VIVIZ gO r Ir1 a Notary Public for the State of(Yd eL t om, County of Oh do hereby certify that (L6LLr J personally appeared before me this ay of 1 tI FI _ I % s�� �� and acl wledge the dueexecution e application for a stormwater permit. Witness my hand and official seal, SYLVIA NORRIS NOTARY FUE! IC ONSLOW COUNTY, NC MY COMMISSION EXPIRES SEAL My commission expires cln�t_ o2_01 S Form SWU-101 Version 07Jun2010 Page 7 of 7 Permit Number: (to be provided by DWQ) Op W ATEq •��� Q2 OG NCDENR STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM SAND FILTER SUPPLEMENT This form must be filled out on line, printed and submitted with all of the required information. Make sure to also fill out and submit the Required Items Checklist (Section 1/1) and the I&M Agreement (Section IV) I. PROJECT INFORMATION Project name MICAS New River P-683I P-687 MV-22 Hangar Development Contact name Myra W. Jones, P.E. Phone number Date Drainage area number II. DESIGN INFORMATION Site Characteristics (904)791-4666 May 21, 2012 SF-1 Drainage area (AD) 82,905.00 ftZ OK Impervious area 53,815.00 ft2 % Impervious OA) 64.9% % Design rainfall depth (Ro) 1.50 in Peak Flow Calculations 1-yr, 24-hr runoff depth 3.59 in 1-yr, 24-hr intensity 0.15 in/hr Pre -development 1-yr, 24-hr runoff 0.05 ft'/sec Post -development l-yr,24-hrrunoff 0.19 ft3/sec Pre/Post 1-yr, 24-hr peak control 0.14 ft'/Sec Storage Volume Design volume (WQV) 6,529.00 ft' Adjusted water quality volume (WQVAdi) 4,896.75 ft3 Volume contained in the sedimentation basin and on top of the sand filter OK 4,950.00 ft3 Top of sand filter/grate elevation 18.75 ft amsl Weir elevation (between chambers) 16 ft amsl Maximum head on the sedimentation basin and sand filter (IiM.Fev) 3.00 It OK Average head on the sedimentation basin and sand filter (hA) 1.50 It OK Runoff Coefficient (Rv) 0.63 (unitless) Type of Sand Filter Open sand filter? SHWT elevation Bottom of the sand filter elevation Clearance (ds,,r) Closed/pre-cast sand filter? SHWT elevation Bottom of the sand filter elevation Clearance (dsmw) If this is a closed, underground closed sand filter: The clearance between the surface of the sand filter and the bottom of the roof of the underground structure (dS,,,e) N YorN It amsl ft amsl Y YorN 10.00 It amsl 12.50 ft amsl 2.50 RECEIVE, N E, MAY 2 2 .2012 `' - Form SW401-Sand Filter -Revs 2009Septl7 Parts I and II. Project Design Summary, Page 1 of 2 Permit Number: (to be provided by DWQ) S6&mentation Basin Surface area of sedimentation basin (As) Sedimentation basin/chamber depth Sand Filter Surface area of sand filter (AF) Top of sand media filter bed elevation Bottom of sand media filter bed/drain elevation Depth of the sand media filter bed (dF) Coefficient of permeability for the sand filler (k) Outlet diameter Outlet discharge/flowrate Time to drain the sand filter (t) Time to drain the sand filter (t) Additional Information Does volume in excess of the design volume bypass the sand filter? Is an off-line flaw -splitting device used? If draining to SA waters: Does volume in excess of the design volume flow evenly distributed through a vegetated filter? What is the length of the vegetated filter? Does the design use a level spreader to evenly distribute flow? Is the BMP located at least 30ft from surface waters (50ft if SA waters)? If not a closed bottom, is BMP located at least 100ft from water supply wells? Are the vegetated side slopes equal to or less than 3:1 Is the BMP located in a recorded drainage easement with a recorded access easement to a public Right of Way (ROW)? What is the width of the sedimentation chamber/forebay (Wsey)? What is the depth of sand over the outlet pipe (dpipe)? 850.00 ft2 4.50 ft 800.00 ft2 14.00 ft amsl 12.50 ft amsl 1.50 ft 3.50 (fUday) 6.00 in 0.03 fe/sec 40.00 hours 1.67 days vn. Meew nunuum I1, uul IIIdy neeu w ue HIUVdJCU w .........:...A.........:...d ...J.......:l ....... ....A... C....--- Vn. IVICCW IIIIIIIIIIUIII, JUL nldy n UU W uC H1UUdbVU W OK. Submit drainage calculations. Y YorN OK Y YorN OK YorN ft YorN Y YorN OK YorN YorN YorN 10.00 ft OK 1.00 ft OK MAY 2 2.2012 Form SW401-Sand Filter-Rev.5 2009Sept17 Parts I and It. Project Design Summary, Page 2 of 2 �J Permit No. (to be provided by DWQ) IIL 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. Initials Pagel Plan Sheet No. '11�pe CG CG 1. Plans (1" - 50' or larger) of the entire site with labeled drainage area boundaries - System dimensions (length, width, and depth) for both the sedimentation chamber and the filter chamber, Maintenance access, - Flow splitting device, - Proposed drainage easement and public right of way (ROW), - Design at ultimate build -out, - Off -site drainage (if applicable), and - Boundaries of drainage easement. 2. Plan details (1" _= 30' or larger) for the sand filter showing: - System dimensions (length, width, and depth) for both the sedimentation chamber and the chamber, - Maintenance access, - Flow splitting device, - Vegetative filter strip dimensions and slope (if SA waters), - Proposed drainage easement and public right of way (ROW), - Design at ultimate build -out, - Off -site drainage (if applicable), and - Boundaries of drainage easement. CG 3. Section view of the sand filter (1" = 20' or larger) showing: - Depth(s) of the sedimentation chamber and sand filter chamber, - Depth of sand filter media, filter - Connection between the sedimentation chamber and the sand filter chamber and weir elevation, - SHWT elevation, - Outlet pipe, and - Clearance from the surface of the sand filter to the bottom of the roof of the underground structure (if applicable). Gls� 4. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. The results of the soils report must be verified in the field by DWQ, by completing & submitting the soils investigation request form. County soil maps are not an acceptable source of soils information. 5. Supporting calculations (including drainage calculations) �.� 6. Signed and notarized operation and maintenance (0&M) agreement .A14- 7. A copy of the deed restrictions (if required). ECEIV MAY 0 4 2012 Form SW401-Sand Filter-Rev.5 2009Sept17 Part III, Page 1 of 1 .►. Permit Number: (to be provided by DWG Drainage Area Number: Sand Filter Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in 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. Important maintenance procedures: — The drainage area will be carefully managed to reduce the sediment load to the sand filter. — The sedimentation chamber or forebay will be cleaned out whenever sediment depth exceeds six inches. — Once a year, sand media will be skimmed. — The sand filter media will be replaced whenever it fails to function properly after maintenance. The sand filter will be inspected quarterly and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance will be kept in a known set location and will be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. BMP element:_ Piblew—: Trash debris is present. , Ho-- I will iemediate'the emblem: • - Remove the trash/debris. Enh re BMP Adjacent pavement (if applicable) Sediment is present on the pavement surface. Sweep or vacuum the sediment as soon as possible. Perimeter of sand filter Areas of bare soil and/or erosive gullies have formed. Regrade the soil if necessary to remove the gully, and then plant a ground cover and water until it is established. Provide lime and a one -lime fertilizer application. Vegetation is too short or too long. Maintain vegetation at an appropriate height. Flow diversion structure The structure is clogged. Unclog the conveyance and dispose of any sediment offsite. The structure is damaged. Make any necessary repairs or replace if damage is too large for repair. Forebay or pretreatment area Sediment has accumulated to a Search for the source of the sediment and depth of greater than six inches. remedy the problem if possible. Remove the sediment and stabilize or 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 roblems. Weeds are present. Remove the weeds, preferably by hand. If a pesticide is used, wipe it on the plants rather than spraying. Form SW401•Sand Filter O&M-Rev.4 2009Septl7 ECEI tlf/ E MAY 0 4 2012 Page 1 of 3 BMB element: � -. ' - ' Pol ential blew. ..;: • .. • . , ." How 1 willremedlate the blew . Filter bed and underdrain collection system Water is ponding on the surface for more than 24 hours after a storm. Check to see if the collector system is clogged and flush if necessary. If water still ponds, remove the top few inches of filter bed media and replace. If water still ponds, then consult an expert. Outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment offsite. The outlet device is damaged Repair or replace the outlet device. Receiving water Erosion or other signs of damage Contact the NC Division of Water Quality have occurred at the outlet. 401 Oversi ht Unit at 919-733-1786. EVEIVE MAY 0 4 2012 BY:._ - Form SW401-Sand Filter O&M-Rev.4 2009Sept17 Page 2 of 3 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:MCAS New River P-683 / P-687 MV-22 Hangar Development BMP drainage area number: J F- 1 Print name: Carl H. Baker, P.E. Title:Denuty Public Works Officer Address:Buildine 1005 Michael Road, MCB Camp Leieune, NC 28547 Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. a Notary Public for the State of County of do hereby certify that personally appeared before me this/,' day of and acknowledge the due execution of the forgoing sand filter maintenance requirements. Witness my hand and official seal, =�A�.�B20pNTN�ET�T[-:'ETTE�licntam 1,s�j&/�, z SEAL My commission expires �/�� Form SW401-Sand Filter O&M-Rev.4 2o09Septl7 ECEUVE MAY 0 4 2012 BY:_ Page 3 of 3 Permit (to be provided by DWQ) j NCDENR STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM SAND FILTER SUPPLEMENT This form must be filled out on line, printed and submitted with all of the required information. Make sure to also fill out and submit the Required Items Checklist (Section III) and the I&M Agreement (Section IV) Project name Contact name Phone number Date Drainage area number II. DESIGN INFORMATION Site Characteristics MCAS New River P-683 / P-687 MV-22 Myra W. Jones, P.E. (904) 7914666 May 21, 2012 SF-2 Drainage area (AD) 212,500.00 ft2 OK Impervious area 81,260.00 W % Impervious (IA) 38.2% % Design rainfall depth (Ro) 1.50 in . Peak Flow Calculations 1-yr, 24-hr runoff depth 3.59 in 1 -yr, 24-hr intensity 0.15 in/hr Pre -development 1-yr, 24-hr runoff 0.27 ft3/sec Post -development 1-yr, 24-hr runoff 0.33 ft3/sec Pre/Post 1-yr, 24-hr peak control 0.06 ft3/sec Storage Volume Design volume (WQV) 10,360.00 ft' Adjusted water quality volume (WQVAd) 7,770.00 ft3 Volume contained in the sedimentation basin and on top of the sand filter OK 14,384.00 it Top of sand fltedgrate elevation 15 It amsl Weir elevation (between chambers) 13 It amsl Maximum head on the sedimentation basin and sand filter (hm.F;ner) 5.50 ft OK Average head on the sedimentation basin and sand filter (hA) 2.75 It OK Runoff Coefficient (Rv) 0.39 (unitless) Type of Sand Filter Open sand filter? SHWT elevation Bottom of the sand filter elevation Clearance (dsHwT) Closed/pre-cast sand filter? SHWT elevation Bottom of the sand filter elevation Clearance (dsHwr) If this is a closed, underground closed sand filter: The clearance between the surface of the sand filter and the bottom of the roof of the underground structure (ds,,,) YorN ft amsl ft amsl Y YorN 5.00 It amsl 6.00 ft amsl 1.00 a�F�yW,�A,�7\Fj�\OG O� C MAY 2 2 .ZU12 Form SW401-Sand Filter-Rev.5 2009Sep117 Parts I and II. Project Design Summary, Page 1 or 2 Permit Number: (to be provided by DWQ) Sedimentation Basin Surface area of sedimentation basin (As) Sedimentation basin/chamber depth Sand Filter Surface area of sand filter (Ar) Top of sand media filter bed elevation Bottom of sand media filter bed/drain elevation Depth of the sand media filter bed (d,) Coefficient of permeability for the sand filter (k) Outlet diameter Outlet discharge/flowrate Time to drain the sand filter (t) Time to drain the sand filter (t) Additional Information Does volume in excess of the design volume bypass the sand filter? Is an off-line flow -splitting device used? If draining to SA waters: Does volume in excess of the design volume Flow evenly distributed through a vegetated filter? What is the length of the vegetated filter? Does the design use a level spreader to evenly distribute flow? Is the BMP located at least 30ft from surface waters (50ft if SA waters)? If not a closed bottom, is BMP located at least 100ft from water supply wells? Are the vegetated side slopes equal to or less than 3:1 Is the BMP located in a recorded drainage easement with a recorded access easement to a public Right of Way (ROW)? What is the width of the sedimentation chamber/forebay (W J? What is the depth of sand over the outlet pipe (dpipe)? 750.00 ft' yr . V=U, uni imiwn, uuundy nccu iu uc nwrddacu ru 3.00 ft 700.00 ft' vn. IVI=U, 111111n l ul l 1, UUl IIldy Iicum ru uO mUcdbtu ru 7.50 ft amsl 6.00 ft amsl 1.50 It 3.50 (ft/day) 6.00 in 0.28 ft3lsec 40.00 hours OK. Submit drainage calculations. 1.67 days Y YorN OK Y YorN OK YorN ft YorN Y Y or N OK YorN Y YorN OK YorN ft 1.00 it OK i MAY 2 2.2012 Form SW401-Sand Filter-Rev.5 2009Sept17 Parts I and II. Project Design Summary, Page 2 of 2 Permit No. (to be provided by D WQ) 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. Initials Pagel Plan Sheet No. 1. Plans (1" - 50' or larger) of the entire site with labeled drainage area boundaries - System dimensions (length, width, and depth) for both the sedimentation chamber and the filter chamber, - Maintenance access, - Flow splitting device, - Proposed drainage easement and public right of way (ROW), - Design at ultimate build -out, - Off -site drainage (if applicable), and - Boundaries of drainage easement. 2. Plan details (1" = 30' or larger) for the sand filter showing: - System dimensions (length, width, and depth) for both the sedimentation chamber and the chamber, - Maintenance access, filter - Flow splitting device, - Vegetative filter strip dimensions and slope (if SA waters), - Proposed drainage easement and public right of way (ROW), - Design at ultimate build -out, - Off -site drainage (if applicable), and - Boundaries of drainage easement. 3. Section view of the sand filter (1" = 20' or larger) showing: - Depth(s) of the sedimentation chamber and sand filter chamber, - Depth of sand filter media, - Connection between the sedimentation chamber and the sand filter chamber and weir elevation, - SHWT elevation, - Outlet pipe, and - Clearance from the surface of the sand filter to the bottom of the roof of the underground structure (if applicable). 4. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. The results of the soils report must be verified in the field by DWQ, by completing & submitting the soils investigation request form. County soil maps are not an acceptable source of soils information. 5. Supporting calculations (including drainage calculations) 6. Signed and notarized operation and maintenance (0&M) agreement 7. A copy of the deed restrictions (if required). ECEIVE MAY 0 4 2012 BY: Form SW401-Sand Filter-Rev.5 2009Septl7 Part III, Page 3 of 3 Permit Number:��y0!//���� (to be provided by DWQf Drainage Area Number: Z Sand Filter Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in 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. Important maintenance procedures: — The drainage area will be carefully managed to reduce the sediment load to the sand filter. — The sedimentation chamber or forebay will be cleaned out whenever sediment depth exceeds six inches. — Once a year, sand media will be skimmed. — The sand filter media will be replaced whenever it fails to function properly after maintenance. The sand filter will be inspected quarterly and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance will be kept in a known set location and will be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. D111L elemenk •_...r. ;fla e., h Potentiel'pmblem,' -.�,T„ Howl will remedlate the problem Entire BUT Trash/debris is present. Remove the trash/debris. Adjacent pavement (if applicable) Sediment is present on the pavement surface. Sweep or vacuum the sediment as soon as 2ossible. Perimeter of sand filter Areas of bare soil and/or erosive gullies have formed. Regrade the soil if necessary to 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 long. Maintain vegetation at an appropriate hei t. Flow diversion structure The structure is clogged. Unclog the conveyance and dispose of any sediment offsite. The structure is damaged. Make any necessary repairs or replace if damage is too large for repair. Forebay or pretreatment area Sediment has accumulated to a Search for the source of the sediment and depth of greater than six inches. remedy the problem if possible. Remove the sediment and stabilize or 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. (Needs are present. Remove the weeds, preferably by hand. If a pesticide is used, wipe it on the plants rather than spraying. MAY 0 4 2012 Form SW401-Sand Filter O&M-Rev.4 2009Septl7 BY:_ Page 1 of 3 Bhe element Potential blew:.: How I will remediate the probljm Filter bed and underdrain collection system Water is ponding on the surface for more than 24 hours after a storm. Check to see if the collector system is clogged and flush if necessary. If water still ponds, remove the top few inches of filter bed media and replace. If water still ponds, then consult an expert. Outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment offsite. The outlet device is damaged Repair or replace the outlet device. Receiving water Erosion or other signs of damage Contact the NC Division of Water Quality have occurred at the outlet. 1 401 Oversight Unit at 919-733-1786. ECEUVE MAY 0 4 2012 Form SW401-Sand Filter O&M-Rev.4 2009Septl7 page 2 of 3 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:MCAS New River 11-683 / P-687 MV-22 Hangar Development BMP drainage area number: S F— Print name:Carl H. Baker, P.E. Title:Deputy Public Works Officer Address:Buildina 1005 Michael Road, MCB Camp Leieune, NC 28547 Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. a Notary Public for the State of County of do hereby certify that GEC r�O� r personally appeared before me thiS/� day of gXi.L , and acknowledge the due execution of the forgoing sand filter maintenance requirements. Witness my hand and official eal, 14" � �- =A.BONNENETTElicntyarolinae /f SEAL My commission expires IrMAY I 4 2012 Form SW401-Sand Filter O&M-Rev.4 2009Sept17 Page 3 of 3 Permit Number: (to be provided by DWQ) ///��� Op w A TFq ;A Q2 OG m � NCDENR STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM SAND FILTER SUPPLEMENT This form must be filled out on line, printed and submitted with all of the required information. Make sure to also fill out and submit the Required Items Checklist (Section 111) and the I&M Agreement (Section IV) I. PROJECT INFORMATION Project name MICAS New River P-6831 P-687 MV-22 Hangar Development Contact name Phone number Date Drainage area number II. DESIGN INFORMATION Site Characteristics (904)791-4666 May 21, 2012 SF-3 Drainage area (AD) 196,000.00 ft' OK Impervious area 115,730.00 ft2 % Impervious (IA) 59.0% % Design rainfall depth (Ro) 1.50 in Peak Flow Calculations 1-yr, 24-hr runoff depth 3.59 in 1-yr, 24-hr intensity 0.15 in/hr Pre -development 1-yr, 24-hr runoff 0.22 ft'/sec Post -development 1-yr, 24-hr runoff 0.42 ft3/sec Pre/Post 1-yr, 24-hr peak control 0.20 ft'/sec Storage Volume Design volume (WOV) 14,210.00 ft' Adjusted water quality volume (WQVAdi) 10,657.50 it' Volume contained in the sedimentation basin and on top of the sand filter OK 16,459.00 It' Top of sand filter/grate elevation 17 ft amsl Weir elevation (between chambers) 15 ft amsl Maximum head on the sedimentation basin and sand filter (hM.riner) 4.00 ft OK Average head on the sedimentation basin and sand filter (hA) 2.00 ft OK Runoff Coefficient (Rv) 0.58 (unitless) Type of Sand Filter Open sand filter? N Y or N SHWT elevation It amsl Bottom of the sand filter elevation It amsl Clearance (dsw) Closed/pre-cast sand filter? Y Y or N SHWT elevation 8.00 ft amsl Bottom of the sand filter elevation 9.50 ft amsl Clearance (dsFwT) 1.50 If this is a closed, underground closed sand filter: The clearance between the surface of the sand filter and the bottom of the roof of the underground ft structure (ds,.) .�11a:��Lru �`l ��-• MAY 2 2 2U12 Form SW401-Sand Filter-Rev.5 2009Sept17 Parts I and II. Project Design Summary, Page 1 of 2 Permit (to be provided by OWQ) SedinnWitation Basin Surface area of sedimentation basin (As) Sedimentation basin/chamber depth Sand Filter Surface area of sand filter (AF) Top of sand media filter bed elevation Bottom of sand media filter bed/drain elevation Depth of the sand media filter bed (dF) Coefficient of permeability for the sand filter (k) Outlet diameter Outlet discharge/flowrate Time to drain the sand filler (t) Time to drain the sand filter (t) Additional Information Does volume in excess of the design volume bypass the sand filler? Is an off-line flaw -splitting device used? If draining to SA waters: Does volume in excess of the design volume flow evenly distributed through a vegetated filter? What is the length of the vegetated filter? Does the design use a level spreader to evenly distribute flow? Is the BMP located at least 30ft from surface waters (50ft if SA waters)? If not a closed bottom, is BMP located at least 100ft from water supply wells? Are the vegetated side slopes equal to or less than 3:1 Is the BMP located in a recorded drainage easementwith a recorded access easement to a public Right of Way (ROW)? What is the width of the sedimentation chamberlforebay (Wsd)? What is the depth of sand over the outlet pipe (dpipe)? Form SW401-Sand Filter-Rev.5 2009Sept17 1,350.00 ft' vn. Meeu wnumm I1, JUL ulay I=u w ue Iwiedaeu w 3.00 ft 1,350.00 ftZ Jn. meeu nllnIIIIUIu, uur umy lieeu w ue muaaaeu ru 11.00 It amsl 9.50 ft amsl 1.50 ft 3.50 (ft/day) 6.00 in 0.05 ft3/sec 40.00 hours OK. Submit drainage calculations. 1.67 days Y YorN OK Y Y or N OK YorN n YorN Y YorN OK YorN Y Y or N OK YorN it 1.00 it OK MAY 2 2.2012 I Parts I and II. Project Design Summary, Page 2 of 2 Permit No. (to be provided by DWQ) III. REQUIRED ITEMS CHECKLIST 1' 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. Initials Pagel Plan Sheet No. CG 1. Plans (1" - 50' or larger) of the entire site with labeled drainage area boundaries - System dimensions (length, width, and depth) for both the sedimentation chamber and the filter chamber, - Maintenance access, - Flow splitting device, - Proposed drainage easement and public right of way (ROW), - Design at ultimate build -out, - Off -site drainage (if applicable), and / - Boundaries of drainage easement. CG 2. Plan details (1" = 30' or larger) for the sand filter showing: - System dimensions (length, width, and depth) for both the sedimentation chamber and the filter chamber, - Maintenance access, - Flow splitting device, - Vegetative filter strip dimensions and slope (if SA waters), - Proposed drainage easement and public right of way (ROW), - Design at ultimate build -out, Off -site drainage (if applicable), and - Boundaries of drainage easement. CG 3. Section view of the sand filter (1" = 20' or larger) showing: - Depth(s) of the sedimentation chamber and sand filter chamber, - Depth of sand filter media, - Connection between the sedimentation chamber and the sand filter chamber and weir elevation, - SHWT elevation, - Outlet pipe, and - Clearance from the surface of the sand filter to the bottom of the roof of the underground structure (if applicable). 4. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. The results of the soils report must be verified in the field by DWQ, by completing & submitting the soils investigation request form. County soil maps are not an acceptable source of soils information. 5. Supporting calculations (including drainage calculations) 6. Signed and notarized operation and maintenance (0&M) agreement 7. A copy of the deed restrictions (if required). ECEI 49 E MAY 0 4 2012 SY:.—_--- Form SW401-Sand Filter-Rev.5 2009Sept17 Part III, Page 3 of 3 Permit Number: (to be prMded by DWQJ Drainage Area Number:_ Sand Filter Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in 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. Important maintenance procedures: — The drainage area will be carefully managed to reduce the sediment load to the sand filter. — The sedimentation chamber or forebay will be cleaned out whenever sediment depth exceeds six inches. — Once a year, sand media will be skimmed. — The sand filter media will be replaced whenever it fails to function properly after maintenance. The sand filter will be inspected quarterly and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance will be kept in a known set location and will 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 ieaiediate the Problem: Entire BMP _ Trash debris is present Remove the trash/debris. Adjacent pavement (if applicable) Sediment is present on the pavement surface. Sweep or vacuum the sediment as soon as possible. Perimeter of sand filter Areas of bare soil and/or erosive gullies have formed. Regrade the soil if necessary to 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 long. Maintain vegetation at an appropriate height. Flow diversion structure The structure is clogged. Unclog the conveyance and dispose of any sediment offsite. The structure is damaged. Make any necessary repairs or replace if damage is too large for repair. Forebay or pretreatment area Sediment has accumulated to a Search for the source of the sediment and depth of greater than six inches. remedy the problem if possible. Remove the sediment and stabilize or 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 a pesticide is used, wipe it on the plants rather than spraying. ECEOVE� MAY 0 4 2012 Form SW401-Sand Filter O&M-Rev.4 2009Sept17 BY:_ Page e t of 3 BW element: • : .' .'Potential ` blemc 'Haw I will remediate'the problenu Filter bed and underdrain Water is ponding on the surface for Check to see if the collector system is collection system more than 24 hours after a storm. clogged and flush if necessary. If water still ponds, remove the top few inches of filter bed media and replace. If water still ponds, then consult an expert. Outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment offsite. The outlet device is damaged Repair or replace the outlet device. Receiving water Erosion or other signs of damage Contact the NC Division of Water Quality have occurred at the outlet. 401 Oversight Unit at 919-733-1786. Form SW401-Sand Filter O&M-Rev.4 2009Sept17 Page 2 of 3 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:MCAS New River P-683 / P-687 MV-22 Hangar Development BMP drainage area number:_�F Print name:Carl H. Baker, P.E. Title:Deputy Public Works Officer Address: Building 1005 Michael Road MCB Camp Le'eune NC 28547 Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. a Notary Public for the State of County of do hereby certify that s/ii personally appeared before me this//10 day of and acknowledge the due execution of the forgoing sand filter maintenance requirements. Witness my hand and official seal, M ETTEictyrolina e SEAL My commission expires E E IVE MAY 0 4 2012 Form SW401-Sand Filter O&M-Rev.4 2009Septl7 Page 3 of 3 Permit Number: j (to be provided by DWQ) QF WATFH NCDENR STORMINATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM SAND FILTER SUPPLEMENT This form must be filled out on line, printed and submitted with all of the required information. Make sure to also fill out and submit the Required Items Checklist (Section fill and the 1&M Agreement (Section IV) I. PROJECT INFORMATION Project name MCAS New River P-683 / P-687 MV-22 Hangar Development Contact name Myra W. Jones, P.E. Phone number (904) 791-4666 Date May 21, 2012 Drainage area number S174 II. DESIGN INFORMATION Site Characteristics Drainage area (Au) 164,785.00 ft' OK Impervious area 76,267.00 ft2 % Impervious (IA) 46.3% % Design rainfall depth (Ro) 1.50 in Peak Flow Calculations 1-yr, 24-hr runoff depth 3.59 in 1-yr, 24-hr intensity 0.15 in/hr Pre -development 1-yr, 24-hr runoff 0.19 ft'/sec Post -development 1 -yr, 24-hr runoff 0.30 ft3/sec Pre/Post 1-yr, 24-hr peak control 0.11 ft3/sec Storage Volume Design volume (WQV) 9,681.00 ft' Adjusted water quality volume (WQVAdi) 7,260.75 ft' Volume contained in the sedimentation basin and on top of the sand filter OK 10,765.00 ft' Top of sand filter/grate elevation 15 ft amsl Weir elevation (between chambers) 13 fit amsl Maximum head on the sedimentation basin and sand filter (hM.FJler) 3.00 It OK Average head on the sedimentation basin and sand filter (hA) 1.50 ft OK Runoff Coefficient (Rv) 0.47 (unitless) Type of Sand Filter Open sand filter? N Y or N SHWT elevation ft amsl Bottom of the sand filter elevation ft amsl Clearance (dsHWr) Closed/pre-cast sand filter? Y Y or N SHWT elevation 7.00 ft amsl Bottom of the sand filter elevation 8.50 It amsl Clearance (dSHWT) 1.50 If this is a closed, underground closed sand filter: The clearance between the surface of the sand filter and the bottom of the roof of the underground It structure (dspace) Form SW401-Sand Filter-Rev.5 2009Sept17 i MAY 2 2 .ZU12 Parts I and 11. Project Design Summary, -Page 1 of :: Sedimentation Basin Surface area of sedimentation basin (As) Sedimentation basin/chamber depth Sand Filter Surface area of sand filter (AF) Top of sand media filter bed elevation Bottom of sand media filter bed/drain elevation Depth of the sand media filter bed (dF) Coefficient of permeability for the sand filter (k) Outlet diameter Outlet discharge/flowrate Time to drain the sand filter (t) Time to drain the sand filter (t) Additional Information Does volume in excess of the design volume bypass the sand filter? Is an off-line flow -splitting device used? If draining to SA waters: Does volume in excess of the design volume flow evenly distributed through a vegetated filter? What is the length of the vegetated filter? Does the design use a level spreader to evenly distribute flow? Is the BMP located at least 30ft from surface waters (50ft if SA waters)? If not a closed bottom, is BMP located at least 100ft from water supply wells? Are the vegetated side slopes equal to or less than 3:1 Is the BMP located in a recorded drainage easement with a recorded access easement to a public Right of Way (ROW)? What is the width of the sedimentation chamber/forebay (Wsvy)? What is the depth of sand over the outlet pipe (dpipe)? Form SW401-Sand Filter-Rev.5 2009Sept17 Permit Number: (to be provided by DWQ) 1,250.00 ff2 V(\. lvl=LW 11111 III I I u I I I, uul IIldy Ilum w ue IIIbledbtu w 3.00 It 1,250.00 ft2 vry viccw unmiuum, uut may uccu ry uc niul edbeu w 10.00 it amsl 8.50 it amsl 1.50 It 3.50 (fVday) 6.00 in 0.05 ft3/sec 40.00hours OK. Submit drainage calculations. 1.67 days Y Y or N OK Y Y or N OK YorN it YorN Y YorN OK YorN Y YorN OK YorN It 1.00 It OK MAY 2 2.2012 Parts I and II. Project Design Summary, Page 2 of 2 Permit No. (to be provided by DWQ) r 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. Initials Pagel Plan SheetNo. t 6 1. Plans (V - 50' or larger) of the entire site with labeled drainage area boundaries - System dimensions (length, width, and depth) for both the sedimentation chamber and the filter chamber, - Maintenance access, - Flow splitting device, - Proposed drainage easement and public right of way (ROW), - Design at ultimate build -out, - Off -site drainage (if applicable), and - Boundaries of drainage easement. 2. Plan details (1" = 30' or larger) for the sand filter showing: - System dimensions (length, width, and depth) for both the sedimentation chamber and the filter chamber, - Maintenance access, - Flow splitting device, - Vegetative filter strip dimensions and slope (if SA waters), - Proposed drainage easement and public right of way (ROW), - Design at ultimate build -out, - Off -site drainage (if applicable), and - Boundaries of drainage easement. 3. Section view of the sand filter (1" = 20' or larger) showing: - Depth(s) of the sedimentation chamber and sand filter chamber, - Depth of sand filter media, - Connection between the sedimentation chamber and the sand filter chamber and weir elevation, - SHWT elevation, - Outlet pipe, and - Clearance from the surface of the sand filter to the bottom of the roof of the underground structure (if applicable). 4. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. The results of the soils report must be verified in the field by DWQ, by completing & submitting the soils investigation request form. County soil maps are not an acceptable source of soils information. _ 5. Supporting calculations (including drainage calculations) _fk,�d _ 6. Signed and notarized operation and maintenance (0&M) agreement 7. A copy of the deed restrictions (if required). ECEIVE MAY 0 4 2012 Form SW401-Sand Filter-Rev.5 2009Sept17 Part III, Page 3 of 3 Perini[ Number: '�5�y////� (to be provided by DWQ) Drainage Area Number: "( Sand Filter Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in 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. Important maintenance procedures: - The drainage area will be carefully managed to reduce the sediment load to the sand filter. - The sedimentation chamber or forebay will be cleaned out whenever sediment depth exceeds six inches. - Once a year, sand media will be skimmed. - The sand filter media will be replaced whenever it fails to function properly after maintenance. The sand filter will be inspected quarterly and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance will be kept in a known set location and will be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. rBMP element; _� G, Potential problem.. - How I will'rethediate the problem: Entire BMP Trash/debris is present.. Remove the trash/debris. Adjacent pavement (if Sediment is present on the Sweep or vacuum the sediment as soon as applicable) pavement surface. possible. Perimeter of sand filter Areas of bare soil and/or erosive Regrade the soil if necessary to remove the gullies have formed. 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 long. Maintain vegetation at an appropriate height. Flow diversion structure The structure is clogged. Unclog the conveyance and dispose of any sediment offsite. The structure is damaged. Make any necessary repairs or replace if damage is too large for repair. Forebay or pretreatment area Sediment has accumulated to a Search for the source of the sediment and depth of greater than six inches. remedy the problem if possible. Remove the sediment and stabilize or dispose of it in a location where it will not cause un acts 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 roblems. Weeds are present. Remove the weeds, preferably by hand. If a pesticide is used, wipe it on the plants rather than spraying. ECE VE Form S W40I-Sand Filter O&M-Rev.4 2009Sept 17 MAY 0 40 2012 Page 1 of 3 BhT element:. - Potential; blem: ' . . .How I will remedietc theproblem:. Filter bed and underdrain Water is ponding on the surface for Check to see if the collector system is collection system more than 24 hours after a storm, clogged and flush if necessary. If water still ponds, remove the top few inches of filter bed media and replace. If water still ponds, then consult an expert. Outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment offsite. The outlet device is damaged Repair or replace the outlet device. Receiving water Erosion or other signs of damage Contact the NC Division of Water Quality have occurred at the outlet. 401 Oversight Unit at 919-733-1786. Form SW401-Sand Filter O&M-Rev.4 2009Septl7 Page 2 of 3 Y 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:MCAS New River P-683 / P-687 MV-22 Hangar Development BMP drainage area number: SF— 4 Print name:Carl H. Baker, P.E. Title:Deputy Public Works Officer Address:Buildiniz 1005 Michael Road, MCB Camp Leieune, NC 28547 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 subdiNision has been named the president. I,41, is ,/,z�r , a Notary Public for the State of r/// County of do hereby certify that personally appeared before me this day of and acknowledge the due execution of the forgoing sand filter maintenance requirements. Witness my hand and official seal, EAU. SO:NETEary Pow CNortolin����on Exd.Z-2 SEAL My commission expires �� 4 f j `i ! c ±r't i,t'' MAY I 4 2012 Form SW401-Sand Filter O&M-Rev.4 2009Septl7 Page 3 of 3 Permit No. (to be provided by DWQ) OF W A TF9 ODGRMG PICDEIdR STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM RAINWATER HARVESTING SUPPLEMENT This form must be filled out, printed and submitted. The Required Items Checklist (Pert Ill) must be printed, filled out and submitted along with all of the required information. I. PROJECT INFORMATION Project name MCAS New River P-6831 P-687 MV-22 Hangar Development Contact person Myra W. Jones, P.E. Phone number (904) 791-4666 Date Drainage area number II. DESIGN INFORMATION Site Characteristics Captured Horizontal Surface Area of Roof 110,000 it, Are you in Coastal County SA waters or ORW Areas? No Storage Volume: Non -SA Waters I Other Design rainfall Qa`,r/jffol 1.5 in Rain Harvesting VolumePfevid_ed (Must include a factor of safety at 10693.757 ft3 least 1.2x design rainfall) Rain Harvesting Volume Provided 80000.00 gal Storage Volume: SA Waters & Saltwater ORW Areas Runoff Volume generated from 1.5' it, 1-yr, 24-hr rainfall depth at your site in Pre -Development 1-yr, 24-hr Runoff it, Post -Development 1-yr, 24-hr Runoff it, 1-yr, 24-hr Runoff Volume Post -Pre 0.00 ft3 Use 1.5" or Pre/Post? Volume of Rainwater Harvesting System Provided Rain Harvesting Volume Provided at Site ��%�� 10,693.76 ft3 Factor of Safely 1.20 Rain Harvesting Volume Provided 80000.00 gal Fill out Non -SA Watem/Other Section OK Chrism Volume Must be at least 1.2X Design Rainfall Runoff Do not fill out this section Do not fill out this section Do not fill out this section Do not fill out this section Do not fill out this section Minimum Rainwater Harvesting Volume must be at least 1.2 times the Runoff Volume Volume Must Have a Safety Factor of 1.2 ECEIVEJ`j. MAY 0 4 2012 Form SW401-Rainwater Harvesting-Rev.3 Pans I. & II. Design Summary, Page 1 of 3 ' Permit No. (to be provided by DWQ) % Runoff % Runoff Used On -Site 65 % Primary Method Used On -Site vehicle washing % Runoff Treated On -Site 35 % Primary Method of Treatment Infiltration Basin % Runoff Infiltrated On -Site 0 % Total Runoff Accounted For 100 % OK Water Balance Calculations Attached? Yes Cistern Overflow, Gutter, & Gutter Downspout Sizing) Closest City Wilmington Captured Roof Area 110000 ffz Overflow Pipe Diameter Needed (in Dec. Inches) 18 in Maximum Captured Area for above Overflow Pipe 110000 ffz OK Guttering Number of Gutters Total 24 gutters diameters, downspout sizing and areas going to each Do you have a plan details showing numbered gutters? Yes Please include plan details showing numbered gutters Do you have a detailed table showing slopes of all gutters? No gutters Do you have a detailed table showing diameters of all gutters? No gutters Do you have a detailed table showing downspout diameterof all No Please include a detailed table showing downspout guders? diameter of all gutters Do you have a detailed table showing maximum captured area for Please include a detailed table showing maximum all gutters? Yes captured area for all gutters Additional Design Elements Have you modeled this system using a water harvesting model? Yes OK Days to Draw Down Rainwater Harvester 5 days Overflow discharged to: Properly Designed BMP OK Does the overflow discharge directly to impervious surfaces? No OK What is the overflow velocity for the 10-year storm? 2.5 R/S Is the overflow velocity non -erosive Yes velocity Is a First Flush Diverler Used? Yes If First Flush Diverter used, where is bypassed water discharged to? Properly Designed BMP OK Actual City Jacksonville, NC Closest City Wilmington Average Annual Historic Rainfall at your Site in Percent of Rainfall that will Overflow Cistern % Additional Design Elements Which Model? Does this cistern have a dedicated year-round use? Yes OK Screen Sizing at Entrance to Rainwater Harvester mm Do you have a secondary water supply to the rainwater harvester? No Plans for the fooling included in submittal? No cistern at full capacity is greater than the soils will If cistern is buried, calculations must be provided to Is the cistern buried? Yes show cistern will not float when empty Pump provided? What is the pressure? psi What are the designated uses of the pump? Are Pump Sizing Calculations Attached? qq E G E p1g V E A Is Cistern Metal? If Metal Cistern - Is Waterproof Bladder Provided? MAY 0 4 2012 If the only use is irrigation - are plans provided? Labeled as non -potable water? Are Local & Stale pumbing codes followed? BY' -----'----- Farm SW401-Rainwater Harvesting-Rev.3 Parts I. & R. Design Summary, Page 2 of 3 Permit (to be provided by DWQ) Does this roof area deduct BUA from calculations of ano?her BMP? If so, what BMP? Yes SF-7 "�CEU VE Mar 0 4 2012 BY:_ Form SW401-Rainwater Harvesting-Rev.3 Parts I. & II. Design Summary, Page 3 of 3 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. Pagel Plan Initials Sheet No. 1 Plans (i" - 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), - Rain Haniester dimensions, - Pretreatment system, Any first flush bypass system, Maintenance access, Proposed drainage easement and public right of way (ROW), Overflow device, and Boundaries of drainage easement. 2. Partial plan (1" = 30' or larger) and details of rain harvester showing: - Maintenance access Volume Area overflow is directed to and appropriate details of overflow area including vegetation, seeding plan and side slopes - Screen sizing - Waterproof bladder if applicable - Footings - Pump design and sizing - Guttering with sizing and slopes, overflows, and - Filler strip. 3. Section view of the roof and rain harvester (1" = 20' or larger) showing: Pretreatment and treatment areas, and Inlet and outlet structures. 4. Rain harvesters shall not be used for sediment and erosion control during construction. 5 A table of elevations, areas, gutter slopes, gutter and overflow dimensions, incremental volumes & accumulated volumes for overall site to verify volume provided. A construction sequence that shows how the rain harvester will be implemented on site. 7' The supporting calculations. &' A copy of the signed and notarized operation and maintenance (O&M) agreement. g' A copy of the deed restrictions (if required). 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. p y 11 A copy of the printout from the water harvesting model used. E C E Q �y 12 A copy of average annual rainfall at your site. MAY U 4 2012 By: Form SW401-Rainwater Harvesting-Rev.3 Part III. Required Items Checklist, Page 1 of 1 PermitNumber:_5 � f///'5 (to be provided by DW2) Drainage Area Number: Rainwater Harvesting System Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in 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. Important maintenance procedures: — The roof area will be maintained to reduce the debris and sediment load to the system. Excess debris can clog the system and lead to bypass of the design storm, and reduced reuse volume. — To ensure proper operation as designed, a licensed Professional Engineer, Landscape Architect, or other qualified professional will inspect the system annually. — The system components will be repaired or replaced whenever they fail to function properly. — If the outlet is metered, use must be recorded at a minimum of monthly. These records shall be kept on site for inspection by DWQ. The system will be inspected by the owner/operator at least monthly and within 24 hours after each rain event. Records of operation and maintenance will be kept in a known set location and will be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. BMP element: Potentialproblems: How to remediate theproblem: The entire system A component of the system is damaged or leaking. Make any necessary repairs or replace if dama a is too large for re air. Water is flowing out of the overflow pipe during a design rainfall or smaller (usually a 1" or 1.5" rainfall). Check system for clogging and damage. Repair as needed so the design volume is stored properly without discharging during a design storm. Check that the pump is operating properly and that the water is actually being used at the volume designed. If it is still not operating properly, then consult an expert. The captured roof area Excess debris or sediment is Remove the debris or sediment as soon as resent on the rooftop. ossible. The gutter system Gutters are clogged, or water is backing up out of the Unclog and remove debris. May need to install gutter screens to prevent future clogging. gutter system. Rooftop runoff not making it into gutter system. Correct the positioning or installation of gutters. Replace if necessary to capture the roof runoff. Form SW401-Rainwater Harvesting O&M-Rev.l MAY 0 4 2012 Page 1 of 3 BY:.__ Permit Number: (to be provided by DWQ) Drainage Area Number: HMP element: Potentialproblems: How to remediate the problem - The pump Pump is not operating Properly. Check to see if the system is clogged and flush if necessary. If it is still not operating, then consult an expert. The overflow pipe Erosion is evident at the overflow discharge point. Stabilize immediately. The overflow i e is clogged. Unclog or replace if it cannot be unclogged. The outflow pipe is damaged. Re air or replace the i e. The secondary water supply Not operating properly. Consult an expert. The cistern Sediment accumulation of 5% Remove sediment. or more of the design volume. Algae growth is present inside the cistern. Do not allow sunlight to penetrate the cistern. Treat the water to removeprevent algae. Mosquitoes in the cistern. Check screens for damage and repair/replace. Treat with 'mosquito dunks' if necessary The screens and filters Debris and/or sediment has accumulated. Screens and filters are clogged. Search for the source of the debris/sediment and remedy the problem if possible. Clean/clear debris/sediment from screen or filter. Re lace if it cannot be cleaned. Form SW401-Rainwater Harvesting O&M-Rev.I 1 MAY I 4 2012 ;s^ Page 2 of 3 w Permit Number: (to be provided by DWQ) Drainage Area Number: 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:MCAS New River.tP7-683 / P-687 NW-22 Hangar Development BMP drainage area number: RAl/Ip 4,cr ArvessiM �rsiewt Print name:Carl H. Baker, P.E. Title:Deputy Public Works Officer Address:Building 1005 Michael Road, MCB Camp Leieune, NC 28547 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> �`' < ��/JPi// a Notary Public for the State of County of 64r16cl do hereby certify that personally appeared before me this day of �_2G,z . , and acknowledge the due execution of the forgoing rooftop management maintenance requirements. Witness my hand and offi seal, [A" A. BONNETTE Notary Public OnaIOW County State of North Carolina Commlaelon Ex ireacV:Z� SEAL My commission expires 7 Form SW401-Rainwater Harvesting O&M-Rev.I cial MAY 0 4 2012 Page 3 of 3 l' p Permit No. �w0'9zz&_5 (to be provided by DINO) WA)pgOG O=� C STORMWATER MANAGEMENT PERMIT APPLICATION FORM a� 7 NCDENR 401 CERTIFICATION APPLICATION FORM INFILTRATION BASIN SUPPLEMENT This form must be filled out, printed and submitted. The Required Items Checklist (Part )ll) must be printed, filled out and submitted along with all of the required information. I'=:PROJECT.INF.ORMATION Project Name P688 APRON EXPANSION PHASE II Contact Person DAVID TOWLER _ Phone Number 910; 451-3238 . Dale 3-Feb-10 -. ,• , .. ,,.:. _ „_ Drainage Area Number .1^(T - II`DESIGN'INFORMAT ION ' 5rh Site Characteristics Drainage area 2,587,759.00 ,ftz - Impervious area --.2,439,933.00 ' ftZ Percent impervious 0.94 % Design rainfall depth - " 1.50 ..'''in Peak Flow Calculations 1-yr, 24-hr rainfall depth -, . 3.51 ..'' in " 1-yr, 24-hr intensity _ - 0.15 inmr Pre -development 1-yr, 24-hrdischarge 40.81 ff'Isec Post -development 1-yr, 24-hr discharge ii '- 130.41 ff'/sec Pre/Post 1-yr, 24-hr peak flow control 89.60 ft'/sec Storage Volume: Non -SA Waters - Minimum design volume required _ 291,123.00 it' Design volume provided - 291,198.00 ft' OK for non -SA waters Storage Volume: SA Waters 1.5" runoff volume ft' Pre -development 1-yr, 24-hr runoff volume ` ft' Post -development 1-yr, 24-hr runoff volume : • it, Minimum required volume ft' Volume provided ,ff' Soils Report Summary Soil type 1_:"..,.SM Sand . Infiltration rate - 5.00 inmr SHWT elevation r 9.00 fmsl Basin Design Parameters _ Drawdown time - 0.18 -. days OK Basin side slopes -'3.33 :1 OK Basin bottom elevation 11.00fmsl OK Storage elevation 12.80 fmsl Storage Surface Area 165,415.00 : If Top elevation 47.00 '-"fmsl Basin Bottom Dimensions Basin length - • 414.06 . H Basin width %387.00 '- ft Bottom Surface Area - 160,218.00 ' it' r �c�crrr�n MAR 1 2 2010 IBY: I Form SW401-Infiltration Basin-Rev.4 Parts 1. & II. Design Summary, Page 1 of 2 Permit No. (ro bo provided by DWO) Additional Information Maximum runoff to each inlet to the basin? 2.00 ac-in OK Length of vegetative filler for overflow 450.00 ft OK Distance to structure 20.00 It OK Distance from surface waters >50 It OK Distance from water supply well(s) > 100 It OK Separation from impervious soil layer > 7 ft OK Naturally occuring soil above shwt Y tt OK Bottom covered with 4-In of clean sand? Y (Y or N) OK Proposed drainage easement provided? N/A (Y or N) OK Capures all runoff at ultimate build -out? Y (Y or N) OK Bypass provided for larger storms? Y (Y or N) OK Pretreatment device provided Y oiVwater separator Form SW401-Infiltration Basin-Rev.4 Parts I. & 11. Design Summary, Page 2 of 3 1 Permit (to be provided by DWD) n III'QREQUIRED ITEMS CHECKLISTk 1 4 "'' ;_ �• ir' 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. . Pagel Plan Initials Sheet No. SWO03 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. At,� SWO04 2. Partial plan (1" = 30' or larger) and details for the infiltration basin showing: - Bypass structure, - Maintenance access, - Basin bottom dimensions, - Basin crass -section with benchmark for sediment cleanout, Flow distribution detail for inflow, Vegetated filter, and Pretreatment device. Aug SWO06-SWOO, 3. Section view of the infiltration basin (1" = 20' or larger) showing: - Pretreatment and treatment areas, and - Inlet and outlet structures. AU6 Attached 4. A table of elevations, areas, incremental volumes & accumulated volumes to verify the volume provided. hug Attached 5. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. The results of the soils report must be verified in the field by DWO, by completing & submitting the soils investigation request form. County soil maps are not an acceptable source of soils information. SWO02 6. A construction sequence that shows how the infiltration basin will be protected from sediment until the entire drainage area is stabilized. Ail Attached 7. The supporting calculations. A i.((L Attached 8. A copy of the signed and notarized operation and maintenance (0&M) agreement. h NIA 9. A copy of'the deed restrictions (if required). MAR 1 2 2010 BY: Form SW401-Infiltration Basin-Rev.4 Page 1 of 1 Part III. Required Items Checklist, Page 1 of 1 „ Alp NCDENR 2�F W�ArFgO 11_JIIJIJI' Dlii�I STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM LEVEL SPREADER, FILTER STRIP AND RESTORED RIPARIAN BUFFER SUPPLEMENT This form must be completely filled out, printed and submitted. DO NOT FORGET TO ATTACH THE REQUIRED ITEMS CHECKLIST AND ALL REQUIRED ITEMS (NEXT WORKSHEET)I L PROJECT INFORMATION Project name P688 APRON EXPANSION PHASE II - Contact name DAVID TOWLER Phone number 910 - 451 - 3238 Dale 5-Mar-10 Drainage area number II DESIGN INFORMATION For Level Spreaders Receiving Flow From a BMP `` ►► �_ '7 �( • { Type of BMP Drawdown Flow from the BMP — cfs For Level Spreaders Receiving Flow from the Drainage Area Drainage area Impervious surface area Percent impervious Rational C coefficient. Peak flow from the 1 in/hr storm Time of concentration Rainfall intensity, 10-yr storm Peak flow from the 10-yr storm Where Does the Level Spreader Discharge? To a grassed biorelention cell? To a mulched biorelention cell? To a wetland? To a filter strip or riparian buffer? Other (specify) Filter Strip or Riparian Buffer Characterization (if applicable) Width of grass Width of dense ground cover Width of wooded vegetation Total width Elevation at downslope base of level lip Elevation at top of bank of the receiving water Slope (from level lip to to lop of bank) Are any draws present? Level Spreader Design Forebay surface area Feet of level lip needed per cfs Answer 'Y” to one of the following: Length based on the 1 in/hr storm? Length based on the 10-yr storm? Length based on the BMP discharge rate? Design flow Is a bypass device provided? 2,267,215.00 ftz Jdiee;—Joel Eve— o 2,267,215.00 ft2 100.00 % 0.95 49.45 cfs 23.00 min 3.5 in/hr 173.06 cfs (Y or N) (Y or N) (Y or N) Y (YorN) Please complete filter strip characterization below. 387.00 It 0.00 It 0.00 If 387.00 It 11.20 fmsl 8.00 fmsl 0.83 % OK N (Y or N) OK 4,308.00 sq it OK 13 ft/cfs N (YorN) Y (Y or N) 17t�k� N (Y or N) 20.65 cfs N (YorN) A bypass device is not neede . L AR M1 2 2010 Form SW401-Level Spreader, Filter Strip, Restored Ripanan Buffer-Rev.5 LPgrt6.1:.ond:li.Oeslgn:Summary,-pagall of 2. • 'Length of the level lip 114.00 ft Are level spreaders in series? N (Y or N) t Bypass Channel Design (if applicable) Does the bypass discharge through a wetland? (Y or N) Do not complete this section of the worksheet. Does the channel enter the stream at an angle? (Y or N) Do not complete this section of the worksheet. Dimensions of the channel (see diagram below): Do not complete this section of the worksheel. M ft Do not complete this section of the worksheet B ft Do not complete this section of the worksheet. W ft Do rot complete this section of the worksheet. . y ft Do not complete this section of the worksheeL Peak velocity in the channel during the 10-yr storm cfs Do not complete this section of the worksheet. Channel lining material __. Do not complete this section of worksheet. y I �_ ------- M _____� M i D i r`. ,—i'il v ' MAR 1 2 2010 Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Parts I. and If. Design Summary, page 2 of 2 III. REQUIRED ITEMS, CHECKLIST 5 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. Pagel Plan Initials Sheet No. _AL6_ SW003 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), - Forebay (if applicable), - High flow bypass system, - Maintenance access, - Proposed drainage easement and public right of way (ROW), and - Boundaries of drainage easement. A L(5 SWO04 2. Plan details (1" = 30' or larger) for the level spreader shoving: - Forebay (if applicable), - High flow bypass system, - One foot topo lines between the level lip and top of stream bank, - Proposed drainage easement, and - Design at ultimate build -out. a Li3 SWO08 3. Section view of the level spreader (1" = 20' or larger) showing: - Underdrain system (if applicable), - Level lip, - Upslope channel, and - Downslope filter fabric. A W N/A 4. A date -stamped photograph of the filter strip that clearly shows the type of vegetation that is present. ALB SWO02 5. A construction sequence that shows how the level spreader will be protected from sediment until the entire drainage area is stabilized. ALS Attached 6. The supporting calculations. Ali 8 Attached 7. A copy of the signed and notarized operation and maintenance (0&M) agreement. AFL N/A 8. A copy of the deed restrictions (if required). MAR 1 2 2010 Form SW401-Level Spreader, Filter Strip, Restored Riparian Buffer-Rev.5 Part III, page 1 of 1 Permit Number: 5�8 09 l3 (to be provided by DWQ) Drainage Area Number: 1 Filter Strip, Restored Riparian Buffer and Level Spreader Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in 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. Important maintenance procedures: — Immediately after the filter strip is established, any newly planted vegetation will.be.watered twice weekly if needed until the plants become established,., (commonly six weeks). — Once a year, the filter strip will be reseeded to maintain a dense growth of vegetation — Stable groundcover will be maintained in the drainage area to reduce the sediment load to the vegetation. — Two to three times a year, grass filter strips will be mowed and the clippings harvested to promote the growth of thick vegetation with optimum pollutant removal efficiency. Turf grass should not be cut shorter than 3 to 5 inches and may be allowed to grow as tall as 12 inches depending on aesthetic requirements (NIPC, 1993). Forested filter strips do not require this type of maintenance. — Once a year, the soil will be aerated if necessary. — Once a year, soil pfl will be tested and lime will be added if necessary. After the filter strip is established, it will be inspected quarterly and within 24 hours after every storm event greater than 1.0 inch (or 1.5 inches if in a Coastal County). Records of operation and maintenance will be kept in a known set location and will be available upon request. Inspection activities shall. be performed as follows. Any problems that are found shall be repaired immediately. BMP element: Potentialproblem: How I will remediate theproblem: The entire filter strip Trash/debris is present. Remove the trash/debris. system The flow splitter device The flow splitter device is Unclog the conveyance and dispose (if applicable) clogged. of any sediment off -site. The flow splitter device is Make any necessary repairs or damaged. replace if damage is too large for repair. APR 01 2010 Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page l of 3 BMP element: Potentialproblem: How I will remediate theproblem: The swale and the level The swale is clogged with Remove the sediment and dispose lip sediment. of it off -site. The level lip is cracked, Repair or replace lip. settled, undercut, eroded or otherwise damaged. There is erosion around the Regrade the soil to create a berm end of the level spreader that that is higher than the level lip, and shows stormwater has then plant a ground cover and bypassed it. water until it is established. Provide lime and a one-time fertilizer application. ' Tiees or shrubs have begun Remove them7 to grow on the swale or just downslo e of the level lip. The bypass channel Areas of bare soil and/or Regrade the soil if necessary to erosive gullies have formed. remove the gully, and then reestablish proper erosion control. Turf reinforcement is Study the site to see if a larger damaged or ripap is rolling bypass channel is needed (enlarge if downhill. necessary). After this, reestablish the erosion control material. The filter strip Grass is too short or too long Maintain grass at a height of (if applicable). approximately three to six inches. Areas of bare soil and/or Regrade the soil if necessary to 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. Sediment is building up on Remove the sediment and the filter strip. restabilize the soil with vegetation if necessary. Provide lime and a one- time fertilizer application. Plants are desiccated. Provide additional irrigation and fertilizer as needed. 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. Nuisance vegetation is Remove vegetation by hand if choking out desirable species. possible. If pesticide is used, do not allow it to get into the receiving water. The receiving water Erosion or other signs of Contact the NC Division of Water damage have occurred at the Quality local Regional Office, or the outlet. 401 Oversight Unit at 919-733-1786. APR 01 2010 Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 2 of 3 • Permit [Number: '5 . & D9 (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:P688 Apron Expansion Phase II BMP drainage area number: Print name:Carl H. Baker, P.E. Title:Deputy Public Works Officer Address:1005 Michael Rd., MCB Camp Lejeune, NC 28547 Date: J —10 —0 Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. a Notary Public for the State of County ofdo hereby certify that // personally appeared before me thisAe �/� ,and acknowledge the due execution of the day of , �ZG< forgoing filter strip, riparian buffer, and/or level spreader inrequirements. Witness my hand and official seal, ALICE A SONNETTblic E Notary Pu Onalow County State of North Carolina My Commission Expires Oct 23. 2010 SEAL My commission expires C-(�/l�c/d R CRE V E—D APR 01 2W Form SWU401-Level Spreader, Filter Strip, Restored Riparian Buffer O&M-Rev.3 Page 3 of 3 Permit Number. (to be provided by DWQ) Drainage Area Number: Infiltration Basin Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in 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. Important maintenance procedures: — The drainage area will be carefully managed to reduce the sediment load to the infiltration basin. — Immediately after the infiltration basin is established, the vegetation will be watered twice weakly if needed until the plants become established (commonly six weeks). — No portion of the infiltration basin will be fertilized after the initial fertilization that is required to establish the vegetation. — The vegetation in and around the basin will be maintained at a height of approximately six inches. After the infiltration basin is established, it will be inspected once a quarter and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance will be kept in a known set location and will be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. BMP element: Potentialproblem: How I will remediate theproblem: The entire BMP Trash/debris is present. Remove the trash/debris. The perimeter of the Areas of bare soil and/or Regrade the soil if necessary to infiltration 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. The inlet device: pipe or The pipe is clogged (if Unclog the pipe. Dispose of the swale applicable). sediment off -site. The pipe is cracked or Replace the pipe. otherwise damaged (if applicable). Erosion is occurring in the Regrade the swale if necessary to swale (if applicable). smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid future problems with erosion. MAR 1 2 2010 Form SW401-Infiltration Basin O&M-Rev.3 BMP element: Potentialproblem: How I will remediate theproblem: The forebay Sediment has accumulated Search for the source of the and reduced the depth to 75% sediment and remedy the problem if of the original design depth. possible. Remove the sediment and dispose of it in a location where it will not cause impacts to streams or the BMP. Erosion has occurred or Provide additional erosion riprap is displaced. 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 pesticides are used, wipe them on the plants rather than Brain. The main treatment area A visible layer of sediment Search for the source of the has accumulated. sediment and remedy the problem if possible. Remove the sediment and dispose of it in a location where it will not cause impacts to streams or the BMP. Replace any media that was removed in the process. Revegetate disturbed areas immediately. Water is standing more than Replace the top few inches of filter 5 days after a storm event. media and see if this corrects the standing water problem. If so, revegetate immediately. If not, consult an appropriate professional for a more extensive repair. Weeds and noxious plants are Remove the plants by hand or by growing in the main wiping them with pesticide (do not treatment area. spray). The embankment Shrubs or trees have started Remove shrubs or trees to grow on the embankment. immediately. An annual inspection by an Make all needed repairs. appropriate professional shows that the embankment needs repair. 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 NC Division of Water damage have occurred at the Quality 401 Oversight Unit at 919- outlet. 733-1756. MAR 1 2 2010 Form SW401-Infiltration Basin O&M-Rev.3 Permit Number: 41'O8 C I I I I �% (to be pro vicled by DWQ) I acknowledge and agree by my signature below that 1 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:P688APPRIDN EXPANSION PHASE II BMP drainage area number: I Print name:Carl H. Baker. P.E. Title:Dcputy Public Works Officer Address: Building 1005 Michael Road Date: 02 - q — /D Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. I, Azlu a Notary Public for the State of , County of do hereby certify that personally appeared before me this day of �.y Fria , and acknowledge the due execution of the forgoing infiltration basin maintenance requirements. Witness my hand and official seal, ALICE A BONNETTE Notary Public Onslow County State of North Carolina My Commiulon Expires Oct 231 2010 SEAL My commission cxpires_�� Form SW401-Infiltration Basin O&M-Rev.3 MAR 1 2 2010 Page 3 of 3 MEMORY TRANSMISSION REPORT TIME :06-18-'12 07:17 FAX NO.1 :910-350-2004 NAME :DENR Wilmington FILE NO. 457 DATE 06.18 07:15 TO : 8 919104512927 DOCUMENT PAGES LO START TIME 06 1 07:15 END TIME 06.18 r,( 7:17 PAGES SENT10 STATUS OR / *** SUCCESSFUL TX NOTICE ' 8[ate o(NotSh Carotiva Depertm�evt of Svvlrvemevt vvd ]VvmYa3 Aeeovrvee wummoten wdloe•3 ome. Div Q� 6vw Rn4r�� Governor FAX COVER SHEET paa R�sswvw� 9�vtetvry Co: C-d it Gib r� �.. c. /J�<_� Phove: (910) 796r'J336 00101350-2004 Re: �6�A ff'O/O /+ �,!'P�r is s i a �✓ �/f.r./S E7_G l2> CaNinW IMv� Lnenslon. Wll+nlnMury NC 2990! � (91O) 796-T235 � M E9nJ Oppnrt�nld AlIIrtne3lve Melon EmP3^Yar 'MEMORY TRANSMISSION REPORT TIME :06-18-'12 07:10 FAX NO.1 :910-350-2004 NAME :DENR Wilmington FILE N0, 455 DATE 06.18 07:07 TO 8 919104512927 DOCUMENT PAGES 9 START TIME 06.18 07:08 END TIME 06.18 07:10 O PAGES SENT S I o J STATUS : OK *** SUCCESSFUL TX NOTICE seaea arxw.-rr. c..vRwa Dapartmaut or HOHlmmazer awd Natural Rrourar Wltalvotou Aapboal Orha Ilrlvr(1• Ra1r6 Plfpaa. povuroor FwX COV812 9tlEHT Dw L}arwaw. 8aoratary Co: �d Grp Gam✓ c //��-"P Pz.: C9101796-7336 127 C.. .-. C 28: ., - (91.) >9b-'1211 • An P. . A-nnn ISmrloy.r� Beverly Eaves Perdue, Governor State of North Carolina Department of Environment and Natural Resources Wilmington Regional Office FAX COVER SHEET Date: _ 4g —/O —o O �- To: Co: �d mtea' Dee Freeman, Secretary No. Pages (excl. cover): From: Jo Casmer Phone: (910) 796-7336 Fax: py/D l ' � / - z Z - Fax: (910) 350-2004 Re: ! ��� //���0 // <�X�Q it 5 i o % 14/ ,9.5 E .741-1n1'Z /"pd,'�ic4 Aioi✓ is s dPc/— -a/ e, / ��S P�o�� /77 � S �O /1 ��//Y%a T, �'1 �. %L /��I C�i'eez ZP C✓ 127 Cardinal Drive Extension, Wilmington, NC 28405 • (910) 796-7215 • An Equal Opportunity Affirmative Action Employer MEMORY TRANSMISSION REPORT TIME :06-18-'12 07:12 FAX NO.1 :910-350-2004 NAME :DENR Wilmington FILE NO. 456 DATE 06.18 07:08 TO 8 919 0447 57 887 DOCUMENT PAGES 10 START TIME 06.18 07:10 END TIME 06.18 07:12 PAGES SENT 10 STATUS OR *** SUCCESSFUL TX NOTICE *** Staav of Not4h Cvroliuv D�pvrtmvet of 8evlrovmevt vvd Nvtutal Rrouraw W4mbptov Reybval OlOta ne..�r0•Evtm rwiW.�, Govarvor FAX COVHR 9HF.ET LaiP a�vvw, 9v�ratvry Dalc: G �/B_ Zo � s— No. vagea (9xcl. covor): 9 Toc _ ���r c_s F.e,m: JO Cnwmor '�/>✓/�i- Pft.: e9101796-7336 (91 Ol 350-2004 ]2, CardWalOel— IIannnglory Wllming[en. NC 28403 (910)>9b>213 MFiqunl OVVortvni[y AtHctun[!va Aetlnn 6mD]oYv State of North Carolina Department of Environment and Natural Resources Wilmington Regional Office Beverly Eaves Perdue, Governor FAX COVER SHFET Dee Freeman, Secretary Date: - � —/,?— ZO�i �;- To: // 1 Z-cZ J o h Co: Fax: ��� — �f �s — 78I? Re: No. Pages (excl. cover): / From: Jo Casmer Phone: (910) 796-7336 Fax: (910)350-2004 127 Cardinal Drive Extension, Wilmington, NC 28405 • (910) 796-7215 • An Equal Opportunity Affirmative Action Employer Levvis,Linda From: Luman, Travis M. [Travis.Luman@haskell.com] Sent: Friday, June 15. 2012 11:26 AM To: Lewis, Linda Subject: RE: SW8 091113 Linda, Yes, the original 2,587,759 sf drainage area for IB-1 already includes the area where the MV-22 Hangar is now located. It is part of the "future" allocation from the original permit. The highlighted note on my Drainage Table (from the Application) discusses the future allocation from the original permit and how it is now being used. The RHS overflow is, of course, Hangar rooftop drainage. I see that the Volume Calculation in your spreadsheet added the 34,960 sf to the 2,587,759 sf to obtain the amount of 2,622,719 sf, but the Drainage Area should still be the original 2,587,759 sf. I have stayed within the bounds of the original drainage area calculations and there is, in fact, still 39,790 sf BUA still available for future use. I hope this answers your question but if you need anything further, please don't hesitate to ask or even give me a call Thanks for your help and quick response! Travis M. Luman, P.E. (FL) I Haskell Architects and Engineers [ 904.357.4271 1 Travis. LumanCcDhaskell.com From: Lewis,Linda[mailto:Iinda.lewisCclncdenr.gov] Sent: Friday, June 15, 2012 9:36 AM To: Luman, Travis M. Subject: SW8 091113 Travis - I think the Infiltration Basin calculations need to be tweaked again to increase the drainage area by the amount of roof area that is not being collected and stored in the RHS tank. Did the original 2,587,759 sf drainage area for IB-1 already include the area where the MV-22 Hangar will now be located? If not, please increase the DA for I13-1 by 34,960 sf and revise those IB-1 calculations. That should take care of everything. The permit is drafted and can be issued upon receipt of the revised Basin Information sheet (DA columns — if necessary) and the revised calculations. You can scan and email all that to me. These changes do not result in any physical changes to the basin itself — it's just a numbers game at this point. Thanks. 44/ HASKELIL ARCHITECTS AND ENGINEERS, P.A. Ms. Linda Lewis NC Division of Water Quality 127 Cardinal Drive Ext. Wilmington, North Carolina 28405 910-796-7215 Dear Ms. Lewis: HASKELL rel 904.791-4500 111 Riverside Avenue tax 904.791.4699 Jacksonville, Florida 32202-4950 web www.haskell.com June 11, 2012 Re: MV-22 Aviation Complex Jacksonville, North Carolina Please see Responses to your Comments as provided below: �w� OVII 3 Comment 1: The underdrain calculations need to be redone as well. I don't know exactly why, but I am coming up with much larger minimum underdrain diameters even though am using the same equation that you do. Fortunately, you have specified enough underdrains in each case to accommodate the expected flow through the sand filter media, but I think the calculation of the minimum underdrain diameter needs to be correct. I think the problem may be in the slope — I see that you use 0.5%, but the equation needs the slope to be in feet per foot, so it should be .005. Are you entering 0.5 in the equation or .005? Response 1: You are correct that I used 0.5 in the equation instead of 0.005. Section 5.7 is not specific on which unit to use, but in the step-by-step process it refers to % in Steps 2 and 3; however, I have revised the calculations and the plans are still adequate. Comment 2: The revised calculations must be signed, sealed and dated. Response 2: Noted. All new revisions as well as those previously sent will be re -sent under a new cover and signed and sealed. Comment 3: The Rainwater Harvesting System (RHS) calculations that you submitted are not what I am looking for. They appear to be based on a 1" design storm. Essentially, I need to see your calculations (via the Simple method) of the required minimum volume to capture based on a 1.5" design storm, and whatever the roof BUA is (DA at 100% impervious) that is being directed to that RHS. es onse 3: The treatment volume calculations via the Simple Method are now included in the revised Report. The Supplement Form already reflects these results based on the 1.5" design storm. LLP Comment 4: 1 am concerned that the up -front filtering will cause the incoming flow to slow down, resulting in much more bypassing to the infiltration basin. Did you tell me before that you weren't claiming any volume credit for the RHS and that all of the runoff volume had been accounted for in the infiltration basin? If that's true, then I don't r. 41 HASKELL HASKELL fa 904.791-4500 II I Riverside Avenue faz 904.791.4699 ARCHITECTS AND ENGINEERS, P.A. Jacksonville, Florida 32202-4950 web wv wvhaskell.com need anything else. But, if you are claiming any of the volume credit for the RHS, then I will need to see those calculations. Please include the location of the bypass line in the schematic details you provided. Response 4: The RHS is claiming volume credit for the constant year-round use of vehicle - washing. As shown in the Supplement (and now supported in the revised report) 65% of the roof drain collection is designed to be stored in the RHS while 35% is designed to go to the infiltration basin. The up -front filtering unit is designed to filter the stormwater below the influent and effluent pipe inverts, thus not reducing the effluent flow. See attached brochure of CDS unit. Also, see revised sheet P-701 showing the bypass line according to the civil layout. Comment 5: 1 am looking into an error in the BMP Manual for the volume provided in the sand filter (vertical box only). Essentially, the volume provided in a vertical box sand filter is only what is above the sand surface on the sand side up to the external overflow weir, and what is above the internal weir elevation on the sediment side up to the external overflow elevation. When runoff enters the sediment chamber, the volume below the weir into the sand chamber will never be able to drain into the sand chamber, so that volume cannot be included as part of the provided volume. The BMP Manual, however, just uses Hmax multiplied by the sum of the two chamber surface areas to determine the volume provided. When I get it resolved, I will be back in touch. Response 5: 1 have reviewed the BMP Manual across my calculations, plans and details and have come to the conclusion that my details for SF-1 on Sheet CG-513 are in error. As you can see from Sections A & B, I have shown the 2'x1' internal weirs set to the top of Hmax which does not allow all of the Hmax volume in the Sedimentation Chamber to make it to the Sand Chamber. I have revised the detail to show the bottoms of the internal weirs set at the top of the sand media, thereby being able to treat all 3' of Hmax. Thank you for your time and assistance on this project. Respectfully, Travis M. Luman, P.E. tml CC: Thomas Bradshaw, MCB Public Works File FIASKELL HASKELL tel 904.791-4500 ® ,Hl Riverside Avenue fax 904.791.4fi99 Transmittal acksonville, Florida 32202-4950 web www.haskell.com ARCHITECTS AND ENGINEERS, P.A. To: Ms. Linda Lewis DATE: June 11, 2012 NCDENR Wilmington Office 127 Cardinal Drive Extension Wilmington, North Carolina 28405 PROJECT: MV-22 Hangar Complex Development SUBJECT: NCDENR High Density RAI 2 MICAS New River Package 1 of 1 Jacksonville, North Carolina 6601220 We are sending you ® herewith the following documents on this project. ❑ under separate cover NUMBER COPIES DRAWING NUMBER DATED TITLE OR DESCRIPTION PREPARED BY 2 6/11/12 Revised Report including Underdrain Pipe Sizing & Haskell RHS calculations__ 2 P-701 6/11/12 Rainwater Harvesting Diagram Haskell 1 6/11/12 Responses to Comments (RAI 1) Haskell 1 Revised Drainage Table from Section IV of Haskell Application These documents are being submitted to you: ❑ For your use. ❑ Please sign and return both copies; one executed copy will be returned to you ❑ For estimating purposes. ® For your approval. Please return (1) copy "APPROVED" or, "APPROVED AS NOTED". ❑ Approved. ❑ Due to revisions. Please acknowledge receipt, advising if these revisions will affect the ❑ Approved as noted. contract price. ❑ For REMARKS: COPIES TO: Mr. Thomas Bradshaw — MCB Public Works Mr. Kenneth J. Boeser Ms. Myra W. Jones Mr. Michael R. McCarthy Mr. Larry W. Willis Very truly yours, HASKELL ARCHITECTS AND ENGINEERS, P.A. Trav4 M. Luman, 6P.E. Civil Engineer RECEIVED LJUN 12.zutz __ -___- U a High Density Stormwater Modification RAI P-683 / P-687 MV-22 (Hangar Development MCAS New River at Camp Lejeune Jacksonville, North Carolina Prepared for: North Carolina Department of Environmental and Natural Resources Wilmington Regional Office 127 Cardinal Drive Extension Wilmington, NC 28405 (910) 796-7215 Prepared by: Haskell Architects and Engineers 111 Riverside Ave Jacksonville, FL 32202 (904)791-4500 June 11, 2012 'CEIVED JUN 12 .2012 BY:SwBoglll 3 �'1 Erosion & Sedimentation Control and High Density Stormwater Modification Reports for P-683 / P-687 MV-22 Hangar Development MCAS New River at Camp Lejeune Jacksonville, North Carolina Prepared for: North Carolina Department of Environmental and Natural Resources Wilmington Regional Office 127 Cardinal Drive Extension Wilmington, NC 28405 (910) 796-7215 RECEIVED MAY 0 4 2012 BY:__ Prepared by: Haskell Architects and Engineers 111 Riverside Ave Jacksonville, FL 32202 (904) 791-4500 April 26, 2012 This submittal package addresses a request for additional information (RAI) received from NCDENR for the modification of High Density Permit SW8 091113. Table of Contents Basin SF-1: Sand Filter 1. Basin Summary 2. Sand Filter Treatment Volume 3. Sand Filter Box Geometry 4. Underdrain Pipe Sizing Basin SF-2: Sand Filter 1. Basin Summary 2. Normal Depth of Swale 3. Sand Filter Treatment Volume 4. Sand Filter Basin Geometry 5. Underdrain Pipe Sizing Basin SF-3: Sand Filter 1. Basin Summary 2. Sand Filter Treatment Volume 3. Sand Filter Basin Geometry 4. Underdrain Pipe Sizing Basin SF-4: Sand Filter (Basin) 1. Basin Summary 2. Normal Depth of Swale 3. Sand Filter Treatment Volume 4. Sand Filter Basin Geometry 5. Underdrain Pipe Sizing Basin RHS: Rainwater Harvesti 1. Basin Summary 2. Treatment Volume Required 3. Treatment Volume Provided Appendices Appendix A — Drainage Basin Characteristics RECEIVED JUN 12 ZG12 F_t Y Erosion & Sedimentation Control and High Density Stormwater Modification Reports for P-683 / P-687 MV-22 Hangar Development Project Location: Onslow County, Jacksonville, NC Marine Corps Air Station New River South of the intersection of Curtis and Longstaff Roads Project Areas: 24.34 acres total drainage area 90.73 acres total disturbed area 85.09 acres additional disturbed area to Permit ONSLO-2010-105 0.00 acres surface water area 0.62 acres wetland impacts River Basin: White Oak Stream Class: New River (SC; NSW) Stormwater Classification: High Density Development Overall Project Description: The overall MV-22 Hangar Development project combines both the P-683 and P-687 maintenance hangars into one combined hangar at MCAS New River (MCASNR) in Jacksonville, North Carolina. The hangar facility will provide maintenance and administration spaces in support of the MV-22 aircraft squadrons. This project also includes design and construction of a privately owned vehicle (POV) parking garage. The three-story parking garage is designed for 1254 vehicles to accommodate the hangar facility. These facilities will be located between Runway 01/19 to the west and the bank of New River to the east. Additionally, the hangar facility will be located adjacent to the east side of a new parking apron, as described in the companion projects below. An existing residential housing area and ball field complex are located within the proposed development's project limits. The housing has recently been vacated and demolished by others to prepare for construction of the hangar development complex. Further demolition of roadways, utilities and other existing improvements will occur per the design of this project as well. The existing ball fields will be closed and new ball fields will be constructed, also a companion project. Companion Projects: The construction phase of this new P-683/P-687 Hangar project is combined with the construction efforts of the P-311 Parallel Taxiway, P-688 Apron Expansion, P-688B Ball Fields projects and two re -aligned segments of Perimeter Road. A brief description of each project is included below: P-311 Parallel Taxiway and P-688 Parking Apron Expansion: These projects include construction of a new taxiway of bituminous pavement; a new apron of heat resistant concrete pavement; and a relocation of the Compass Rose. These projects also include pavement markings; taxiway lighting; necessary water, storm, electrical and telephone infrastructure to make a complete and usable airfield; along with incidental related work. P-688B Ball fields: This project includes construction of a soccer field, a T-Ball field, and baseball fields for Bronco League, Babe Ruth League, and Mustang League; as well as a concession stand with restrooms. The project shall include the necessary fencing, water, storm, electrical and telephone infrastructure to make a complete and usable support area; along with incidental related work. Perimeter Road: In preparation for the future extensions of Runway 01/19 and the P-311 Parallel Taxiway, Perimeter Road will be re -aligned in accordance with the imaginary surface criteria as established by the Department of Defense's Unified Facilities Codes. A second segment of Perimeter Road will be re -aligned parallel to Runway 05/23 where the roadway currently encroaches upon this surface. The P-688 Apron Expansion project was permitted through the North Carolina Department of Environment and Natural Resources (NCDENR) as High Density under Stormwater Permit SW8 091113. The P-311 Parallel Taxiway and Compass Rose projects were permitted as Low Density under Stormwater Permit SW8 100102. A stormwater infiltration basin with an oil/water separator and energy dissipater was designed for the High Density Apron Expansion project which is to be constructed adjacent to the southern end of the new apron. The P-311 and P-688 projects were permitted as one project for erosion and sedimentation control (ESC) under Permit ONSLO-2010-105. This submittal package seeks to modify the High Density Permit SW8 091113 and the ESC Permit ONSLO-2010-105. A modification to the Low Density Permit SW8 100102 for the Perimeter Road re -alignments will be submitted under separate cover. Stormwater Discussion: The aforementioned separator and basin will receive discharge via trench drains collecting the P-688 Apron runoff as well as the 50-foot hangar access apron adjacent to the east side of the apron. The basin is also designed to treat a portion of the new P-311 Taxiway (though most of which is permitted as low density.) Of particular note, this basin was designed to treat the hangar structure as well. At the time the basin was designed the hangar was planned to be two separate and smaller structures; however, the scope of the hangar design has since been modified. The hangar is now one combined structure and is a larger total area than the basin was originally designed to treat. As part of this project half of the new hangar's rooftop runoff will be routed to the infiltration basin, and the other half will be routed to a new Rainwater Harvesting System (RHS) which will have a dedicated year-round use for washing the MV-22's. Routing only half of the hangar to the infiltration basin will amount to less BUA than the basin originally accounted for, and in addition, one-third of the 50-foot access apron was able to be removed by combining the hangar into one facility further lessening BUA going to the basin. Due to geotechnical information reporting that percolation rates are insufficient for the design of new infiltration basins for this hangar project, the primary Best Management Practice (BMP) for stormwater treatment will be through the use of sand filters. Additional percolation tests were performed in the in -situ clays to verify that they are permissible for use as a bottom liner in the sand filters. There are four sand filters in total. One is of an underground concrete box design and three are of basin designs. All of these, by usage of the clay bottom liner, are considered closed sand filters. Low Impact Development (LID) practices have been considered throughout the stormwater design process. Overland runoff and grassed swales have been utilized to the maximum extent practicable in order to minimize the use of closed pipe culvert systems. This project is also scoped to achieve a LEED status of Silver, at a minimum. LEED credits have been sough wherever possible, including stormwater quality and quantit I MAY 0 < cult The majority of MCASNR was developed throughout the 1940's during Worla�War_ll and much of the housing was constructed in the 1960's and 1970's; thus pre -dating NCDENR permitting requirements. The pre -development drainage pattern is reflected on sheets CJ-001 through CJ- 009 and displays how most of the stormwater discharges through piped culvert and grassed swale systems to wooded riparian buffers and wetlands and then directly to New River with no upstream treatment measures. The post -development drainage pattern is reflected on sheets CK-001 through CK-009 and shows seven drainage divides: four sub -basins are directed to new Best Management Practices (BMP,) two sub -basins encompass each half of the hangar — one to the infiltration basin and the other to the RHS, and one sub -basin is a pocket of redevelopment which will continue to drain in the same manner as in existing conditions. Modification to High Density Permit SW8 091113: The Parking Apron was permitted for 2,439,933 ft2 of BUA. Of that total 1,999,165 ft2 is Apron BUA; 172,718 ft2 is Taxiway BUA; and 268,050 ft2 is "future" BUA reserved for the 50-foot wide hangar access apron as well as for the hangar itself. As summarized in Section IV of the permit application, the proposed hangar contributes 110,000 ft2 of BUA from rooftop runoff as well as an additional 38,710 ft2 from the Rainwater Harvesting System overflow. The proposed access apron contributes 83,300 ft2 of BUA; thus, the total BUA from this project going to the infiltration basin is 232,010 ft2 (36,040 ft2 less than the "future" allotment factored into the basin design.) This permit modification will not modify the infiltration basin design or functionality, but rather, this modification will expand the permitted area to include the hangar and garage along with new BMP designs. Modification to ESC Permit CINSLO-2010-105: A modification to Permit ONSLO-2010-105 was previously submitted for the surcharge and water main construction efforts which were considered Phase 1. The current permit, which applies to the Taxiway and Apron companion projects, is considered Phase 2. For the purposes of this modification the MV-22 Hangar Development, along with the Perimeter Road re- alignments, will be considered Phase 3. Land Disturbances: The existing ESC permit was approved for 107.00 acres of land disturbance. The Phase 1 ESC modification created an additional disturbance of 6.68 acres. This second modification for Phase 3 will create 90.73 acres of land disturbance of which 85.09 acres are additional. Of the 90.73 acres, 80,73 acres will be due to construction efforts (of which 19.08 acres will be new BUA,) and approx. 20.00 acres will be for construction staging, hauling and material lay -down areas. The material lay -down areas will not create disturbed land and thus will not require further erosion and sedimentation control measures. Three temporary skimmer sediment basins will be constructed in the locations of the permanent sand filter basin BMP's, SF-2, SF-3 and SF-4. The roadway re -alignments will consist of shoulders and grassed swales (no curb and gutter.) Discussion of Construction Sequences: Phase 1 deals with two segments of water main construction necessary to install and connect prior to excavation and surcharging efforts can take place. Phase 2 will continue clearing, demolition, and grading efforts for the Taxiway, Apron and Compass Rose. The excavated infiltration basin will act as a temporary sediment basin for Phase 2 work. Phase 3 construction efforts for the Hangar, POV Garage and Perimeter Road re -alignments cannot begin until all necessary stormwater, ESC and wetland permitting is complete. It is anticipated that Phase 1 will be complete and Phase 2 will be well into preliminary grading by the time Phase 3 can begin. Once ESC measures for Phase 3 have been installed, diversion swales and skimmer sediment basins can then be constructed. Clearing and grubbing, tree removal, utility removal and other related demolition will follow. Underground infrastructure, such as water/sewer/storm/gas piping and electrical/communications conduits, will be installed. Once the hangar and garage are staked, preliminary grading can begin and will coincide with grading efforts for the Apron. All the while appropriate stabilization timeframes for denuded areas and stockpiles will be followed, and the stormwater pollution prevention plan with its record of updates will be kept on -site. Riparian Buffers and Wetlands: This site is located in Onslow County which is a coastal county. Per the regulations set forth by the Coastal Area Management Act (CAMA,) a federal consistency determination must be obtained through NCDENR's Division of Coastal Management. No Phase 3 construction efforts are anticipated to occur within the 75-foot Area of Environmental Concern (AEC); thus remaining outside any 50-foot riparian buffers as well. This site is also not located near shellfish (SA) waters. A jurisdictional determination for the wetlands has been obtained for this project. There are 0.62 acres of known, unavoidable, permanent wetland impacts. There are also 0.18 acres of temporary wetland impacts which will be restored to original conditions. The site discharges to several "blueline streams" as indicated on the USGS Quad Map, Jacksonville South, all of which have been deemed ephemera'I. All runoff from within the high density boundary will be treated through sand filters and then discharge into nearby wetlands heading to New River. The wetland impacts are currently in the permitting review process by NCDENR and the U.S. Army Corps of Engineers. Basin Summaries Basin RHS The basin for the Rainwater Harvesting System (RHS) is comprised solely of rooftop runoff from the Hangar. The northern half of the Hangar will be routed through a piped roof drain system to the RHS where it will be pumped through a filter unit and then into the storage tank. Stored water from the RHS will have a dedicated year-round use of washing the MV-22's on the concrete wash rack located just north of the RHS. Stormwater runoff from the wash rack will enter into a catch basin and be treated in SF-1 as part of the SF-1 basin boundary; however, the discharge from vehicle -washing will enter into the sanitary sewer system to be treated in the wastewater treatment plant due to the anticipated high levels of soaps and chemicals that should not enter into a BMP. In order for this switch from storm sewer to sanitary sewer to happen, the sanitary pipe is set lower than the storm pipe and a gate valve is installed on the sanitary pipe to open it when washing and to keep it closed during normal, non -washing operations. A sign will be posted by the gate valve and yard bibs to offer sufficient instruction for opening and closing the valve. As detailed in the Rainwater Harvesting Supplement Form, the RHS tank is not sized large enough to hold the entire volume captured from the Hangar rooftop. An overflow pipe is installed in the system to not only allow stormwater from an excess storm event to leave the system but also to allow the excess rooftop runoff to leave the system. As noted earlier in this report there is treatment volume available in the infiltration basin for portions of this development that are no longer routed to it, and allowing the excess roof drainage to enter into the basin will not overcome the volume available. Existing Infiltration Basin (per Permit SW8 091113): The basin divide noted in the construction plans as Existing I-B is comprised solely of rooftop runoff from the Hangar. The southern half of the Hangar will be routed through a piped roof drainage system and connected to the parking apron's trench drain which leads to the infiltration basin. This is as anticipated by the design calculations of Permit SW8 091113. The usage of the impervious surface areas from SW8 091113 is detailed in Section IV of this high density application which also footnotes the amount of treatment volume still available in the infiltration basin. Redevelopment Area: There is a 4.22 acre area of residential housing and roads to the north of the Hangar and wash rack that will be completely demolished per this project's scope of design. In post -development this same area will only comprise a portion of the 24-foot wide roadway leading to and from the site. Since this area is 32.5% impervious in existing conditions and will be reduced to 9.9% impervious in proposed conditions, this area will be considered a pocket of Redevelopment; thus, a BMP is not proposed for this area; however, the swale on the westside of the road will discharge to a new catch basin fitted onto an existing pipe which discharges to an existing inlet. The roadway bank on the eastside of the road will tie -down to match existing grades. Project Information and Requirements Knowns: Project Site is not within Y mile of SR or SA waters. Special precautions for outflow regarding SR and SA waters do not need to be followed. Rainfall Depth for Treatment Volumes in Coastal Counties is 1.5 inches. See Vicinity Map for site location relative to state roads. Major Design Elements for BMP's, applicable for this project: Sand Filters: - Vegetated side slopes shall be no steeper than 3:1. - Volume in excess of the 1.5" treatment volume will bypass the filter. - Vegetated Filter Strip is not required for overflows, bypass flows, or discharges. - Sand Filters shall be located a minimum of 30' from surface waters. - SHWT must be at least 1 foot below the bottom of closed filter designs, unless mitigated for. - Maximum contributing drainage basin is 5 acres. One acre or less is preferred. - Minimum width of sedimentation chamber or Forebay shall be 1.5 feet. - Sand Filter must completely drain within 40 hours. - Sand media shall be a minimum of 18" deep (min. 12" over the drainage pipes.) - All sand filter designs must provide sufficient access to both chambers for maintenance. Grassed Swales Not Seeking Pollutant Removal Credits: - Must non-erosively pass the peak runoff rate for the 10-yr storm. - Where practicable, maximum longitudinal slope shall be 5%. - Swales shall convey the design discharge while maintaining a minimum of 0.5' of freeboard and without exceeding the maximum permissible velocity. - Maximum velocity shall be as specified in the NCDENR BMP Manual Table 14-2. - Side slopes shall be no steeper than 3:1. - The majority of the bottom of the swale shall be above the SHWT, but not necessarily 1-ft. of separation. .1 s'JI I EMI ICE i • � iilir�: ■ � of � I Aerial Map (N.T.S.) Marine Corps Air Station New River Jacksonville, North Carolina USGS Quadrangle Map (N.T.S.) Jacksonville South, North Carolina 1997 /ZONE AE R wRM (EL 3)/ZONE X y2 r J1[ '� , tyjE r 1 .NEWELL STT y o, > Gr?ER GRq DO,_11 a' Sr_�k¢(r b-N ZO E �� ��R715 RD ,v ♦ r FFFy� 'e + ZONE X ZONE AEA r I Olt(, _ 4 a (EL 3) i®s 71bx Ir I EA0320 Q621 ZONE X Marine Corps Base Camp Leieune 77. 26'00" Ya e ZONE X—T L ZONE X� yF9 � b� sr GOODEN ST ZONE 276 GRID NORTH P SCALE 1" - 1,0001 (1 : 12,000) Soo 0 1000 2000 FEET PANEL 43W FIRM FLOOD INSURANCE RATE MAP NORTH CAROLINA PANEL 4364 ML LOCATOR OW� OR ~ INM MR RAM FO L IA Fl cows. COMGNNIIY ® No. PANEL SUFFIX roapv.".tr.prvw . .ae Nfb m u,.rn. ay ++.. •+o.. rJo..b+e •....e .w., a�y .w aa..: �Ler aw•.. ,,,�.. air EFFECTIVE DATE MAP NUMBER NOVEMBER 3, 2005 3720436400) it Sure of North Carolina Federal Emergency Management Agency e tm tno jW F a a 0n n a Tti anme oes not r Rooa map. a tener en wlrq h me, m map does eR reflect cM1rte on Nock , For heicM1 nay M1a a tram made s ltout Nero to Fl I on Ina Nock For the Intent product IrRwmation aEou[ NYIonY Flood Insurarce nam Good map cM1•xk tM1e FEMA Flood Map Store Y wevi.mec lama-gov Marine Corps Base Camp Lejeune ../ ZONE %/ z R ZONE AE ONE AE f j 1 70NE x 20NE AE � II 1 y J„� kt •, 1 3ayT' �4 s 9, LCgLf M1NS- , ZONE %' I.. M1 �Y.CS, ZONE x City AOfl ks1n1 11I 370178 ZONE % aREo NonrN ' SCALE 1' - 1,000' (1 : 12.000) SW o Iwo p00 FIRM Cs FLOOD INSURANCE RATE MAP NORTH CAROLINA PANEL 4m www C� fGs'mM SCb1 %tll ,Si.� i �J EFFWW RATE w Now is NOYFYND 3,205 7RO17NOM SYe dNmG C,mlu. Pre -Development Areas Basin `° Total (SF) Impervious I Pervious- Total (ac.) I Impervious;. Pervious PRE 1 82,905 3,275 79,630 1.90 0.07 1.83 PRE 2 212,500 57,481 155,019 4.88 1.32 3.56 PRE 3 196,000 44,394 151,606 4.50 1.02 3.48 PRE 4 164,785 37,204 127,581 3.78 0.85 2.93 PRE RHS 110,000 27,830 82,170 2.53 0.64 1.89 PRE I-B 110,000 9,031 100,969 2.53 0.21 2.32 PRE Redev 1 183,8601 59,828 124,032 4.22 1.371 2.85 Total 1 1,060,050� 239,0431 821,007 24.341 5.48 18.86 Post -Development Areas Basin Total (SF) Impervious I Pervious Total (ac.) I Impervious _Pervious"" SF-1 82,905 53,815 29,090 1.90 1.231 0.67 SF-2 212,500 81,2601 131,240 4.88 1.87 3.01 SF-3 196,000 115,7301 80,270 4.50 2.66 1.84 SF4 164,785 76,267 88,518 3.78 1.75 2.03 RHS 110,000 110,000 0 2.53 2.53 0.00 -B 110,000 110,000 0 2.53 2.531 0.00 Redev 183,860 18,280 165,580 4.22 0.421 3.80 Post-Dev Totals" Basin '-r Total (SF) 11,mpervious 1, Pervious Total (ac.) I Impervious,,I, .Petvious- BMP 656,1901 327,0721 329,118 15.06I 7.511 7.55 Other 1 403,8601 238,2801 165,580 9.281 5.481 3.80 Total 1 1,060,0501 565,3521 494,698 24.341 12.991 11.35 Curve Numbers Impervious 98 Built Upon Area Pervious 39 Open Space - Good Condition Soil Type A Runoff Coefficient, Rv (as calculated by the Simple Method) Rv=0.05+0.9' IA where: IA (Impervious percentage) = Impervious area / Total Area Pre -Development CN and Rv Basin Total (ac.) Impervious Pervious Composite CN IA IRv PRE 1 1.90 0.07 1.83 41 3.95% 0.09 PRE 2 4.88 1.32 3.56 55 27.05% 0.29 PRE 3 4.50 1.02 3.48 52 22.65% 0.25 PRE 4 3.78 0.85 2.93 52 22.58% 0.25 PRE RHS 2.53 0.64 1.89 54 25.30% 0.28 PRE 1-113 2.53 0.21 2.32 44 8.21 % 0.12 PRE Redev 4.22 1.37 2.85 58 32.54% 0.34 RDSt-Development CN and Rv Basin ..- Total (ac.) FimperAousj Pervious Composite CN IA Rv SF-1 1.90 1.23 0.67 77 64.9% 0.63 SF-2 4.88 1.87 3.01 62 38.2% 0.39 SF-3 4.50 2.66 1.84 74 59.0% _ 0.58 SF-4 3.78 1.75 2.03 66 46.3% 0.47 RHS 2.53 2.53 0.00 98 100.0% 0.95 -113 2.53 2.53 0.00 98 100.0% 0.95 Redev 4.22 0.42 3.80 45 9.9% 0.14 Basin SF-1: Sand Filter Box JUN 12 2012 1. Basin Summary This proposed drainage divide is located at the northern end of the hangar and is the smallest of the seven drainage divides due to the many constrictions in locating SF-1. Per MCASNR criteria, the sand filter may not be located underneath pavement; however, the corridor through this area of the site has been narrowed as much as possible in order to reduce wetland impacts so much of this sub -basin consists of roadway pavement. In addition, the new perimeter security fence is aligned through this corridor as well as the many utilities servicing these new facilities. With the limited amount of space available, a concrete box sand filter was designed and located in a grassed area immediately adjacent to the east side of the vehicle wash rack. The treatment area does not include rooftop runoff as that is being routed to the rainwater harvesting tank which will have the sole purpose of washing the MV-22's on a regularly scheduled cycle. Though the discharge from the vehicle washing will be routed to the sanitary system, stormwater runoff will be routed directly to SF-1. The outfall pipe from SF-1 will stub out the bottom of the retaining wall and discharge into a 1- foot deep concrete sump structure to dissipate energy, and then into existing wetlands. There is a significant difference in elevation from the sand filter to the discharge point. In order to cross the many utilities plus be able to achieve a low flow velocity, this pipe will connect to a drop manhole outside the sand filter upstream of the discharge point. 2. Sand Filter Treatment Volume The treatment volume in this Coastal County will be calculated using a rainfall depth of 1.5 inches by the Simple Method as presented in the NCDENR BMP Manual. The runoff coefficient must first be calculated as such: Rv = 0.05 + 0.9 * IA where: Rv = runoff coefficient, unitless IA = impervious fraction, unitless thus: Rv = 0.05 + 0.9 * (53,815 ftz / 82,905 ft2) = 0.63 The volume is now calculated using the following formula: WQV =Rv*A*RD where: WQV = Water Quality Volume (ft) A = watershed area (ft) RD = design storm rainfall depth (ft) therefore: WQV = 0.63 * 82,905 * 1.5 / 12 (ft) WQV = 6,529 ft3 to be treated WQV,dj = 75%(WQV) = 4,897 ft3 (adjusted water quality volume) 3. Sand Filter Box Geometry The sand filter box geometry is calculated using the method in the BMP Manual while also considering the various site and soil conditions and constraints. First, the minimum bottom area for the sedimentation chamber is calculated using the following formula: 7BY: IVED 2 .2012 As = [(240)(Rv)(A)] * RD where: A is in acres, RD is in inches, and 240 is a conversion factor thus: A, = [(240)�0.63)(1.90)] * 1.5 As = 431 f1: The next point to consider before moving forward is the constraint that the seasonal high water table (SHWT) has on the allowable depth of the sand filter. In the vicinity of SF-1, it is estimated that the SHWT is two feet above an existing ground elevation of 8.00 feet. With the proposed top elevation of SF-1 set at 18.50 feet, the sand filter box can be designed up to a 7.5-foot maximum depth. After an iterative process it is therefore concluded that hma, can be no greater than 3.0 feet, A, will equal 850 ft2 and Af will equal 800 ft2. The supporting calculations are below, beginning with hma, and have hmax = WQVadj / (As + Af) thus: hmax = 4,897 / (850+800) = 2.97 ft Use 3.00 ft hava=3.00/2=1.50ft Next, the minimum bottom area for the sand filter chamber must be checked using the following formula: Af = (WQV * 1.5 ft) / 13.5 fpd * 1.136 days * (have + 1.5 ft)] thus: Af = (6,529 * 1.5) / [3.5 * 1.66 * (1.5 + 1.5)] Af = 562 ft2 The minimum areas calculated above are less than the areas stated for design; thus, they are sufficient sizes for each chamber. Now the chambers' areas must be double-checked with hma, to ensure that WQVadj is met by using the following formula: Volume = (A, + Af) * hma, thus: Volume = (1,650) * 3.00 = 4,950 ft3 > 4,897 ft3 4 Adequate See the construction plans and details for sand filter box layout, dimensions and sections. 4. Underdrain Pipe Sizing Per Section 5.7 of the NCDENR Division of Water Quality BMP Manual, the sizing of the underdrain is calculated as such below: D = 16 * [(Q)(n) / �S] (aia) where: Q (cfs) of the sand media = 3.5 ft/day * Area (sand filter bed) = 800 ft2 and calculated with a Factor of Safety = 10 thus: D = 16 * [(0.032*10) cfs * (0.011) / (�0.005)] (38) D = 5.2 inches 4 USE: One 6" PVC pipe down the centirGFhkVE+ D sand filter chamber JUN 1 2 .zu1t 13Y: -_- Basin SF-2: Sand Filter Basin =RFCEI�V�ED 1. Basin Summary This proposed drainage divide is. located to the northeast of the hangar and wraps around the north side of the garage where the sand filter, SF-2, is located. Since SF-2 is located in an area of sufficient open space, it is of a basin design. Due to the many other site constrictions and limited locations for BMP's, however, the grading and drainage of this sub -basin is designed to be close to the maximum allowable drainage area of 5 acres. Grading for overland flow and the use of grassed swales was designed to the maximum extent practicable in an effort to reduce the need for closed pipe systems.. The treatment area does not include rooftop runoff from either the hangar or the garage. The outfall pipe from SF-2 will discharge through a mitered end section, with a concrete sump for energy dissipation, and from there the discharge will flow into existing wetlands. 2. Normal Depth of Swale The majority of the flow into SF-2 will be collected through Swales SF-2A and SF-2B that run alongside the new Curtis Road and into a catch basin which is then piped into the forebay of SF-2. Other runoff from the north side of the garage will be collected into a catch basin and similarly piped into the forebay. The normal depth calculations for these swales are included in the Appendices. Freeboard, SHWT, clearance from the roadway base structure and pipe sizing were considered in the design depth and geometry of this swale as well. 3. Sand Filter Treatment Volume The treatment volume in this Coastal County will be calculated using a rainfall depth of 1.5 inches by the Simple Method as presented in the NCDENR BMP Manual. The runoff coefficient must first be calculated as such: Rv = 0.05 + 0.9 * IA where: Rv = runoff coefficient, unitless IA = impervious fraction, unitless thus: Rv = 0.05 + 0.9 * (81,260 ft2 / 212,500 ft2) = 0.39 The volume is now calculated using the following formula: WQV =Rv*A*RD where: WQV = Water Quality Volume (ft3) A = watershed area (ft) RD = design storm rainfall depth (ft) therefore: WQV = 0.39 * 212,500 * 1.5 / 12 ft WQV = 10,360 ft3 to be treated WQVadl = 75%(WQV) = 7,770 ft3 (adjusted water quality volume) 4. Sand Filter Basin Geometry The sand filter basin geometry is calculated using the methoc considering the various site and soil conditions and constraints. for the forebay is calculated using the following formula: in the BMP Manual while also First, the minimum bottom area RECEIVED JUN 1 2 .ZU1Z BY:_____ As = [(240)(Rv)(A)] * RD where: A is in acres, RD is in inches, and 240 is a conversion factor thus: AS = [(240)�0.39)(4.88)1' 1.5 As = 685 ft The next point to consider before moving forward is the constraint that the SHWT has on the allowable depth of the sand filter. At the location of SF-2 with the groundwater table (GWT) at 16 feet below an existing ground elevation of 16.00 feet, the SHWT being estimated at five feet above the GWT, and the proposed berm elevation of SF-2 set at 15.00 feet; the sand filter basin can be designed up to a 9-foot maximum depth. After an iterative process, hmax will be rounded up to 5.50 ft, AS will equal 750 ft2 and At will equal 700 ft2. The supporting calculations are below, beginning with hmax and have. hmax = WQVadi / (As + Af) thus: hmax = 7,770 / (1,450) = 5.36 ft Use 5.50 ft have = 5.50 / 2 = 2.75 ft Next, the minimum bottom area for the filter must be checked using the following formula: At = (WQV * 1.5 ft) / [3.5 fpd * 1.66 days * (have + 1.5 ft)] thus: At = (10,360 * 1.5) / [3.5 * 1.66 * (2.75 + 1.5)] At = 630 f1:2 The minimum areas calculated above are less than the areas stated for design; thus, they are sufficient sizes for the Forebay and the filter. Now the WQVad; required for the forebay and filter areas is compared to the volume calculated in the stage -storage relationship: Volume provided = 14,384 ft' > WQVad; = 7,770 ft3 4 Adequate See the construction plans and details for basin layout, dimensions and sections. See the stage - storage relationship in the Appendices for verification of the above calculations. 5. Underdrain Pipe Sizing Per Section 5.7 of the NCDENR Division of Water Quality BMP Manual, the sizing of the underdrain is calculated as such below: D = 16 * [(Q)(n) / JS] 13/8) where: Q (cfs) of the sand media = 3.5 ft/day * Area (sand filter bed) = 700 ft2 and calculated with a Factor of Safety = 10 thus: D = 16 * [(0.028*10) cfs * (0.011) / (�0.005)1 (3/8) D = 4.9 inches -* USE: Four 6" PVC pipes for adequate spacing F'CF.I�V�ED JUN 1 2 Basin SF-2 Stage - Area Storage: V = h/3 ' [ Al + A2 + Sgrt(A1 ' A2) ] �p StageSurfaceAreas (ft a.�(sf) vForebay x >Inc>Vcila" �if(ac)Y' (��tl ;'Sand Filter Su face Areas `,._(s � . (ac) lnc'.Vol '(c� Surface!`Areas 4-Volume - (s� (ac) it :(b� �(a4ftia 7.5 0.00_ 700 0.02 - 700 0.02 0.00 8.0 0.00 866 0.02 391 866 0.02 391 0.01 9.0 0.00 _ _ 1,245 0.03 1,050 1,245 0.03 1,441 0.03 10.0 770 0.02 1,680 0.04 1,457 2,450 0.06 2,898 0.07 11.0 1,140 0.03 _ 9.19 2,172 0.05 1,421 3,312 0.08 5,767 0.13 12.0 1,567 0.04 1,348 2,721 0.06 2,441 4,288 0.10 9,557 0.22 12.25 1,688 0.04 407 2,872 0.07 699 4,560 0.10 10,662 0.24 13.0 2,050 0.05 1,399 3,326 0.08 2,322 5,376 0.12 14,384 0.33 14.0 0.00 6,652 0.15 4,894 6,652 0.15 19,278 0.44 15.0 0.00 7,651 0.18 7,146 7,651 0.18 26,424 0.61 Treatment Volume Calculation: Total Contributing Drainage Area = 4.88 ac. R = 0.39 V = 10,630 ft3 1.5" TV Elevation = 12.25 ft Forebay Berm Elevation = 13.00 ft RECEIVED JUN 1 2 .ZU]Z BY: Basin SF-3: . Sand Filter Basin Jul 1 2 .ZU12 1'j �i 1. Basin Summary This proposed drainage divide is located to the east of the garage and treats the entire garage parking structure as well as some sheet flow from the surrounding area. Since SF-3 is located in an area of sufficient open space, it is of a basin design. Grading for overland flow and the use of a grassed swale was designed to the maximum extent practicable in an effort to reduce the need for closed pipe systems. This treatment area does include, however, rooftop runoff from the garage conveyed via PVC roof drain piping. The outfall pipe from SF-3 will discharge through a mitered end section onto'a rip rap pad designed by others. From there the discharge will flow into existing wetlands. 2. Sand Filter Treatment Volume The treatment volume in this Coastal County will be calculated using a rainfall depth of 1.5 inches by the Simple Method as presented in the NCDENR BMP Manual. The runoff coefficient must first be calculated as such: Rv=0.05+0.9*IA where: Rv = runoff coefficient, unitless IA = impervious fraction, unitless thus: Rv = 0.05 + 0.9 * (115,730 ft2 / 196,000 ft2) = 0.58 The volume is now calculated using the following formula: WQV =Rv*A*RD where: WQV = Water Quality Volume (ft) A = watershed area (ft) RD = design storm rainfall depth (ft) therefore: WQV = 0.58 * 196,000 * 1.5 / 12 ft WQV = 14,210 ft3 to be treated WQVadj = 75%(WQV) = 10,658 ft3 (adjusted water quality volume) 3. Sand Filter Basin Geometry The sand filter basin geometry is calculated using the method in the BMP Manual while also considering the various site and soil conditions and constraints. First, the minimum bottom area for the forebay is calculated using the following formula: As = [(240)(Rv)(A)1 * RD where: A is in acres, RD is in inches, and 240 is a conversion factor thus: As = [(240)(0.58)(4.50)) * 1.5 As = 940 ft2 The next point to consider before moving forward is the constraint that the SHWT has on the allowable depth of the sand filter. At the location of SF-3 with the GWT at 16 feet below an existing ground elevation of 19.00 feet, the SHWT being estimated at five feet ab ve the GWT, RECEIVED JUN 1 2 .2012 RY• and the proposed berm elevation of SF-3 set at 17.00 feet; the sand filter basin can be designed up to an 8-foot maximum depth. After an iterative process, hmax will be equal to 4.00 ft and AS and Af will each equal 1,350 ft2. The supporting calculations are below, beginning with hmax and have hmax = WQVadj / (As + Af) thus: hmax = 10,658 / (2,700) = 3.95 ft Use 4.00 ft have=4.00/2=2.00ft Next, the minimum bottom area for the filter must be checked using the following formula: Af = (WQV * 1.5 ft) / [3.5 fpd * 1.66 days * (have + 1.5 ft)] thus: Af = (14,210 * 1.5) / [3.5 * 1.66 * (2.00 + 1.5)] Af = 1,048 ft' The minimum areas calculated above are less than the areas stated for design; thus, they are sufficient sizes for the Forebay and the filter. Now the WQVadj required for the forebay and filter areas is compared to the volume calculated in the stage -storage relationship: Volume provided = 15,728 ft' > WQVadj = 10,658 ft3 4 Adequate See the construction plans and details for basin layout, dimensions and sections. See the stage - storage relationship in the Appendices for verification of the above calculations. 5. Underdrain Pipe Sizing Per Section 5.7 of the NCDENR Division of Water Quality BMP Manual, the sizing of the underdrain is calculated as such below: D = 16 * [(Q)(n) / JS] (3') where: Q (cfs) of the sand media = 3.5 ft/day * Area (sand filter bed) = 1,350 ft2 and calculated with a Factor of Safety = 10 thus: D = 16 * [(0.055*10) cfs * (0.011) / (J0.005)] (3fe) D = 6.4 inches -* USE: Three 6" PVC pipes for adequate spacing RECEIVED JUN 12 2012 BY: Basin SF-3 Stage - Area Storage: V = h/3 * [ Al + A2 + Sgrt(i41 * A2) ] ForebaySanii Filter, ,T,otalsy�� g Stage (ft) Surface (s� Areas �� r(ac)`;� I c, Vdl 3 � (cf) ;l Surface (sf)' .. t� Areas (ac) Inc.'Vol �'(cf) Surface Areas (a�). I111Volume (fit). (agmft) ; 11.0 _ 1,576 0.04 - 1,576 0.04 - 0.00 12.0 338 - 2,075 0.05 1,820 2,413 0.06 1,820 0.04 13.0 1,125 rO=.O3 _ 693 2,630 0.06 2,347 3,755 0.09 4,860 0.11 14.0 2,363 1,706 3,242 0.07 2,931 5,605 0.13 9,497 0.22 14.67 2,759 1 0.06 1,714 3,690 0.08 2,321 6,449 0.15 13,532 0.31 15.0 2,954 0.07 942 3,911 0.09 1,254 6,865 0.16 15,728 0.36 16.0 0.00 8,387 0.19 6,008 8,387 0.19 21,737 0.50 17.0 0.00 _ 9,508 0.22 8,942 9,508 0.22 30,678 0.70 Treatment Volume Calculation: Total Contributing Drainage Area = 4.50 ac. R = 0.58 V = 14,210 ft3 1.5" TV Elevation = t4.67 ft Forebay Berm Elevation =1 15.00 ft JUN 12 .ZOIZ Basin SF-4: Sand Filter Basin (_;C,ty C. JUN 12 .ZbIz 1. Basin Summary This proposed drainage divide encompasses the southern areas of the hangar and garage, and the sand filter, SF-4, is located south of the garage beyond Longstaff Street. Since SF-4 is located in an area of sufficient open space, it is of a basin design. Overland flow and the use of a grassed swale, Swale SF-4, were designed to the maximum extent practicable in an effort to reduce the need for closed pipe systems. The treatment area does not include rooftop runoff from either the hangar or the garage. The outfall pipe from SF-4 will discharge into an outfall pipe system that also captures SF-3 discharge and will outfall through the same mitered end section and rip rap pad (designed by others.) From there the discharge will flow into existing wetlands. 2. Normal Depth of Swale The majority of the flow into SF-4 will be collected through Swale SF-4 that runs alongside the new Curtis Road and into a catch basin which is then piped into the forebay of SF-4. Other runoff from the south side of the: garage will sheet flow directly into the sand filter. The normal depth calculation for this swale is included in the Appendices. Freeboard, SHWT, clearance from the roadway base structure and pipe sizing were considered in the design depth and geometry of this swale as well. 3. Sand Filter Treatment Volume The treatment volume in this Coastal County will be calculated using a rainfall depth of 1.5 inches by the Simple Method as presented in the NCDENR BMP Manual. The runoff coefficient must first be calculated as such: Rv=0.05+0.9*IA where: Rv = runoff coefficient, unitless IA = impervious fraction, unitless thus: Rv = 0.05 + 0.9 * (76,267 ft2 / 164,785 ft2) = 0.47 The volume is now calculated using the following formula: WQV =Rv*A*RD where: WQV = Water Quality Volume (ft) A = watershed area (ft) RD = design storm rainfall depth (ft) therefore: WQV = 0.47 * 164,785 * 1.5 / 12 ft WQV = 9,681 ft3 to be treated WQV,dj = 75%(WQV) = 7,261 ft3 (adjusted water quality volume) 4. Sand Filter Basin Geometry The sand filter basin geometry is calculated using the method in the BMP Manual while also considering the various site and soil conditions and constraints. First, the minimum bottom area for the forebay is calculated using the following formula: (V�, D JUN 12 .zutz i i�zv. As = [(240)(Rv)(A)] * RD where: A is in acres, RD is in inches, and 240 is a conversion factor thus: As = [(240)�0.47)(3.78)1* 1.5 As = 640 f1: The next point to consider before moving forward is the constraint that the SHWT has on the allowable depth of the sand filter. At the location of SF-4 with the GWT at 16 feet below an existing ground elevation of 18.00 feet, the SHWT being estimated at five feet above the GWT, and the proposed berm elevation of SF-4 set at 15.00 feet; the sand filter basin can be designed up to an 7-foot maximum depth. After an iterative process, hmax will be equal to 3.00 ft and As and Af will each equal 1,250 ft2. The supporting calculations are below, beginning with hmax and have hmax = WQVadj / (As + Af) thus: hmax = 7,261 / (2,500) = 2.90 ft Use 3.00 ft have = 3.00 / 2 = 1.50 ft Next, the minimum bottom area for the filter must be checked using the following formula: Af = (WQV * 1.5 ft) / [3.5 fpd * 1.66 days * (have + 1.5 ft)] thus: Af = (9,681 * 1.5) / [3.5 * 1.66 * (1.50 + 1.5)] Af = 833 f1:2 The minimum areas calculated above are less than the areas stated for design; thus, they are sufficient sizes for the Forebay and the filter. Now the WQVadj required for the forebay and filter areas is compared to the volume calculated in the stage -storage relationship: Volume provided = 10,765 ft3 > WQVadj = 7,261 ft3 _* Adequate See the construction plans and details for basin layout, dimensions and sections. See the stage - storage relationship in the Appendices for verification of the above calculations. 5. Underdrain Pipe Sizing Per Section 5.7 of the NCDENR Division of Water Quality BMP Manual, the sizing of the underdrain is calculated as such below: D = 16 * [(Q)(n) / JS] (3fa) where: Q (cfs) of the sand media = 3.5 ft/day * Area (sand filter bed) = 1,250 ft2 and calculated with a Factor of Safety = 10 thus: D = 16 * [(0.051 *10) cfs * (0.011) / (40.005)] 1318) D = 6.2 inches 4 USE: Three 6" PVC pipes for adequate spacing RECEIVED JUN 1 2 ZU1'L L Y:_----- -- Basin SF-4 Stage - Area Storage: V = h/3 ' [ Al + A2 + Sgrt(A1 ` A2) ] <i Yi Stage i yFore,bay c. �Surf6diaikeas i' ,, Inc. Vol. "(S� (ac);;;. (c� SandiFilter_-�-' Surface AreasF (sf)' „(ac)' Inc. Vol (c) a��ySotals..,::",;;y Surfac Areas ', ;Volume ? y (SflCt) (ac-ft).' (f1): 10.0 313 0.01 1 - 1,250 0.03 - 1,563 0.04 - 0.00 11.0 969 0.02 611 1,728 0.04 1,483 2,697 0.06 2,093 0.05 12.0 2,263 0.05 1,571 2,263 0.05 1,989 4,526 0.10 5,654 0.13 12.81 2,742 0.06 2,024 2,742 0.06 2,024 5,483 0.13 9,702 0.22 13.0 2,854 0.07 532 2,854 0.07 532 5,708 0.13 10,765 0.25 14.0 0.00 _ 6,906 0.16 4,733 6,906 0.16 15,498 0.36 15.0 0.00 7,887 0.18 7,391 7,887 0.18 22,889 0.53 Treatment Volume Calculation: Total Contributing Drainage Area = 3.78 ac. R = 0.47 V = 9,681 ft3 1.5" TV Elevation = 12.81 ft Forebay Berim Elevation = 1 3--001 ft k.F.CF1VED JUN 12 .ZU1Z Basin. RHS: Rainwater Harvesting System I�CEIVED JUN 12 .ZOV BY: 1. Basin Summary The basin for the Rainwater Harvesting System (RHS) is comprised solely of rooftop runoff from the Hangar. The northern half of the Hangar will be routed through a piped roof drain system to the RHS where it will be pumped through a filter unit and then into the storage tank. Stored water from the RHS will have a dedicated year-round use of washing the MV-22's on the concrete wash rack located just north of the RHS. Stormwater runoff from the wash rack will enter into a catch basin and be treated in SF-1 as part of the SF-1 basin boundary; however, the discharge from vehicle -washing will enter into the sanitary sewer system to be treated in the wastewater treatment plant due to the anticipated high levels of soaps and chemicals that should not enter into a BMP. In order for this switch from storm sewer to sanitary sewer to happen, the sanitary pipe is set lower than the storm pipe and a gate valve is installed on the sanitary pipe to open it when washing and to keep it closed during normal, non -washing operations. A sign will be posted by the gate valve and yard bibs to offer sufficient instruction for opening and closing the valve. As calculated below and reported in the Rainwater Harvesting Supplement Form, the RHS tank is not sized large enough to hold the entire volume captured from the Hangar rooftop. An overflow pipe is installed in the system to not only allow stormwater from an excess storm event to leave the system but also to allow the excess rooftop runoff to leave the system. As detailed in the Drainage Basin Table in the Application, there is treatment volume available in the infiltration basin for portions of this development that are no longer routed to it, and allowing the excess roof drainage to enter into the basin will not overcome the volume available. 2. Treatment Volume Required The treatment volume in this Coastal County will be calculated using a rainfall depth of 1.5 inches by the Simple Method as presented in the NCDENR BMP Manual. The runoff coefficient must first be calculated as such: Rv=0.05+0.9'IA where: Rv = runoff coefficient, unitless IA = impervious fraction, unitless thus: Rv = 0.05 + 0.9 ' (110,000 ft2 / 110,000 ft2) = 0.95 The volume is now calculated using the following formula: WQV =Rv.A*RD where: WQV = Water Quality Volume (ft) A = watershed area (ft2) RD = design storm rainfall depth (ft) therefore: WQV = 0.95 ' 110,000 . 1.5 / 12 ft WQV = 13,063 ft3 to be treated JUN 12 ZOIZ 3. Treatment Volume Provided After a factor of safety of 1.2 is applied, the total treatment required to size the rainwater harvesting tank is 15,674 ft3 or 117,260 gallons. An 80,000 gallon tank has been selected to be used for this project due to mechanical efficiency of the overall system. As discussed the excess volume collected will drain through the overflow pipe, into the apron trench drain, and ultimately discharge into the existing infiltration basin. The square footage of rooftop runoff that is actually being stored and used in the RHS is verified by the following calculations: 80,000 gallons (tank size) / 1.2 (factor of safety) = 66,667 gal 0005) 66,667 gal / 7.481 gal/ft3 8,911 ft3 (treatment volume provided) Applying the water quality volume: equation, WQV = Rv ` A' RD, where WQV = 8,911 ft3, provides the correlating square footage of rooftop runoff being stored in the RHS: therefore: 8,911 ft3 = 0.95 " A " (1.5/12) ft thus: A = 75,040 ftZ Treatment volume has been provided for 75,040 ft2 of rooftop runoff from the hangar to be stored and used in the RHS. The rooftop area captured by the roof drainage system is 110,000 ftZ leaving 34,960 ftZ designed to bypass the RHS and be accounted for in the existing infiltration basin. JUN 1 2 .Z012 ,s Custom Cistern Optimization Modeling from Wahaso Project: Camp LeJeune VM-22 Hangar Location: Jacksonville, NC e� Water Sources: Rainwater Water Uses: Airplane Washing (57,600 gallons per week) Wc1llc1SO Analysis Date: 3/22/2012 Wahaso's proprietary cistern size optimization model evaluates a range of potential cistern size options to help customers understand the trade-off between storage capacity and the annual savings of municipal water replaced by non -potable sources on -site. Wahaso's model uses six years of actual daily precipitation history for the project location to determine how each cistern option would have performed under actual local conditions day by day. As cistern size increases, a larger percentage of demand can be met from the non -potable source, but there are diminishing returns as the cistern grows. Wahaso's model accurately predicts the average annual water savings at each cistern size so that clients can understand the cost/savings trade off. We then recommend a cistern configuration to optimize the efficiency of the proposed system. Cistern Size % of Total Demand Met Projected Annual Savings of Munic al Water Gallons Change from Previous Increment Rain Event Size Capable of Being Handled (inches): 40,000 57.65% 1,731,674 - 3/4 50,000 61.39% 1,843,977 112,303 1 60,000 64.03% 1,923,168 79,190 1 1/8 70,000 66.04% 1,983,496 60,328 11/3 80,000 67.68% 2,032,773 49,278 11/2 _ 90,000 ..... _. 68.93% 2,070,451 37,678 12/3 _. 100,000 _ _69.98% _ 2,101,894 _ _ 31,443_ _ _ _ _ _ 1 8(9 110,000 70.97% 2,131,785 - 29,891 2 120,000 71.90% 2,159,428 27,643 2 1/4 130,000__ _ 72.73% 2,184,524 25,096 2_4/9 140,000_ _ 73.50% _ _ 2,207,657 _ _. _23,133. _ - _ _ _ _ .. .22/3 _ 150,000 74.11% 2,225,990 18,333 2 5/6 160,000 74.60% 2,240,740 14,749 3 170,000 75.04% 2,253,793 13,053 3 1/5 180,000 75.43% 2,265,459 11,667 3 2/5 190,000 75.81 % 2,277,126 11,667 3 3 5 fable - % of Total Demand Met 100.00% — 90,00 % 58.0% 80.00% _.._...-...... 6).)% 68.9°b )O.O% )1.086 71.9% )l.)% 73.5•/ )4:SWe""")06°/°"'-)5:0%--"')SCOW°-JS.B°b 61.4% 60.00% 57.7% . 50.00% ----- ___-- 40.00% 30.00% 20.00% __.. ......... ......... 10.00% 0,00% 0 0 0 0 0 0 00 0 0 0to 0 --,--, 0 0 0 0 to 0 - 0 0 0 0 , o o a o 0 0 0 0 00 0 0 0 0 0 0 a 0 0 0 Co 0 0 0 m 0 0 0 0 0 0 0 0 ce 0 0 0 0 co 0 0 00 Table - 2 The tables above illustrate the effect of cistern size on the total demand met with the non -potable water supply. In Table- t, Column 4 shows the diminishing return in savings as the cistern size increases. The last column of Table-1 shows the maximum rain event size in inches that the empty cistern could handle. This number is important because we will lose all rain amounts greater than this once this event size occurs. The red marker on Table-2 indicates the % of total demand met by a cistern of an infinite size. This is the maximum possible "% of total demand met" and allows for useful comparisons to be made to the range of cistern sizes. Copyright 2012 - Water Harvesting Solutions, Inc. Fade l of MAY 2 2 .201Z Wahaso c°m 1800590.535013R2/1012 1 T. System Effectiveness; Based on Recommended 100K Gallon Cistern Projected Annual Averages Based On Past Six Years of Actual Daily Rainfall Total Supply Total Demand Harvested Gallons Used Municipal Gallons Used Total Days Requiring Munici al Make -Up 2,682,703 3,003,585 2,101,894 901,691 1 140 Projected Monthly Supply & Demand Rased on Historical 6-Year Daily Rainfall Amounts "/o of Total Demand Met Each Year 6 Year Average Year 1: 66.8% Year 2: 56.6% Year 3: 84.1% 70 0% Year 4: 76.0% Year 5: 69.2% Year 6: 67.3% Supply refers to all of the potential non -potable water that can be harvested. Table-3 breaks down the total municipal gallons into monthly segments. This is helpful in discovering seasonal shortfalls in the system. C suyr r2UII Wafer Rarwssing Solutions,Ire, page 2 of J MAY 2 2.1012 Wanaso.com I800'58055501 5/22/2032 Precipitation Profile for Jacksonville, NC Size of Rain Event: Percent of Rain Events: Annual Averages Past Six Years: .02"-.25" 54% 51 events �' Y4 $ 7 t 21% 20 events .50�1 0 15% 14 events t a 90/0 8 events t 2%a 2 events Average Annual Distribution of Rain Event Sizes ❑ .02"-.25" ❑.25"-.50" 0.50"-1.0" 0 1.0"-2.0" u > 2.0" Note the rain event distribution is unique to each location and is important when considering the storage capacity necessary to ovoid losing rainwater during an event. MAY 2 2 .Z012 Copyright 2012- water Harvesting solutions, Im. Page 3 of waNsoxem I eoa58a535a1 3/22/2012 Wahaso Cistern Optimization Model - Key Input Assumptions Wahaso's Cistern Optimization Model depends on a series of assumptions about a building's water sources and uses to calculate total water savings and model the value of different cistern capacities. Since the analysis is often for buildings that don't yet exist, these assumptions for supply demand are educated guesses. We encourage you to review our assumptions and we are happy to modify these assumptions if you have better numbers or would simply like to see the impact of different variables on the model output. Supply Side Variables Rainwater SupplAssum tions ii Historical rainfall data from: Jacksonville NC Roo fto and or other collection area insquare feet): 1100,000 Discount for loss through evaporation and first flush: 15% Amount of rain from rooftop during 1" rain event (gallons): 62,338 for other supplies if applicable (daily gallons): Demand Side Variables Vehicle WasF in Demand Assum lions Daily Vehicle Washing (Gallons): 8 229 J MAY 2 2.2012 cowrighr 2012 water Harvesting Solutions, inc. 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Model # Surface Area NSBB-2.5-4-60 1 NSBB-3-6-72 1 NSBB-6.5-72 NSBB-4-8-94 N588-5-10.5-84 5: NS1111-6-12-84 1 N58B-8-12-84 S NSBB-8-14-96 1 NSBB-10-14-96 1 www.BioCle'anEnvironmelhtal.com DUAL STAGE Separator �NsaaI Access Hatches Outflow pipe 1 Oil Skimmer • Sediment Chambers— Maximizes TSS removal and eliminates scouring during extreme flow rates. • Skimmer & Boom- Collects hydrocarbons & controls flow velocity which improves removal efficiency. etween Storm Events Trash, debris & organics are stored in a suspended I. •• screen system allowing pollutants to dry out between .. 0 0 storm events. This eliminates septic conditions and ... prevents leaching of plant based organics into water. t ti Built -In Diversion Eliminates the Need for Diversion Structures Installation Low Flow (Fir Flush) Diversion Lake Tahoe, CA ...................... . ......... I..................... 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I ................. • No confined space entry is required for servicing • Cleaning can be accessed through manhole or hatch above ground with vac truck • Separating pollutants minimizes costs - screen system allows gross solids to be removed without vacuuming out water or sediment chambers • Screen systems are hinged for easy access to sediments collected in lower chambers DESIGNED FOR USE WITH STANDARD VACUUM TRUCKS ........................................ Ap p ro yals....................................... S.W FRA XNO O A� NJ! ESTUARY PARTNERSHIP USING NJ CAT RECOMMENDED PSD (67 MICRONS V) C Sit CLEAN Hydrodynamic Separator (NSBB) ......................................................................................................................... Stores trash, debris & organics in screen- ing system separated from water below. Separation Prevents: • Odor • Bacteria Growth • Nutrient Leaching • Septic Conditions Shallow Profile Minimizes Maintenance Cost • Less Shoring • Perfect for Areas with High Ground Water n Results ..................................... Other Separators Trash, debris & organics are captured and stored in standing water. This promotes nutrient leaching, bad odors, bacteria growth and compli- cates maintenance. • High Excavation Cost • Extra Shoring • Challenge with Shallow Ground Water B1 CLEAN cea San Luis Rey Rd Oceanside, CA 92058 p 760.433.7640 f 760.433.3176 www.BioCleanEnvironmental.com Appendix B: Normal Depth Calculations for Swales Precipitation Frequency Data Server Page I of 4 NOAA Atlas 14, Volume 2, Version 3 e.=t' Location name: Jacksonville, North Carolina, US* /4 • Coordinates: 34.7019,-77., i Elevation: 19ft• j source: Google Maps t•\,,,_ POINT PRECIPITATION FREQUENCY ESTIMATES GAL Bou, in, D. Manin, B. Lin, T. Parzybok, M.yekta, and D. Riley NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation, frequency estimates with 90% confidence intervals (in inches)' Average recurrence Interval(years) Duration 1 2 5 �j-����� 10 25 50 100 200 500 1000 0.490 0.578 0.669 0.751 0.848 0.924 1.00 1.08 1.17 1.26 5-min (0.454-0.532) (0.535-0.626) (0,618-0.724) (0.692-0.812) (0.777-0.915) (0.844-0.998) (0.909-1.08) (0.971-1.16) (1.05-1.27) (1.11-1.37) 0.783 0.924 1.07 1.20 1.35 1.47 1.59 1.71 1.85 1.98 10-min (0.725-0.849) (0.856-1.00) (0.989-1.16) 1 (1.11-1.30) 1 (1.24-1.46) 1 (1.34-1.59) (1.44-1.72) (1.54-1.85) (1.66-2.01) (1.75-2.15) 0.979 1.16 1.36 1.52 1.71 1.86 2.01 2.15 2.33 2.48 15-min (0.906-1.06) 1 (1.08-1.26) 1 (1.25-1.47) (1.40-1.64) 1 (1.57-1.85) 1 (1.70-2.01) (1.83-2.17) (1.94-2.33) 12.09-L53) (L20-2.70) 1.34 1.60 1. 33 F 2.20 2.54 2.81 3.08 3.35 3.71 4.02 30-min (1.24-1.46) (1.49-1.74) 1 (1.78-2. 1 (2,03-2,38) 1 (2.32-2.74) 1 (2.56-3.03) (2.80-3.33) (3.02-3.63) (3.32-4.03) (3.56-4.37) 1.67 2.01 2.47 2.87 3.38 3.80 4.24 4.70 5.33 5.87 60-min (1.55-lA2) (1.86-2.18) 1 (2.28-2.67) 1 (2.64-3.10) 1 (3,10-3.65) 1 (3.47-4.11) (3.85-4.58) (4.24-5.08) (4.76-5.78) (5.20-6.38) 2.03 2.46 3.10 3.67 4.45 5.12 5.84 6.61 7.72 8.68 2-hr (1.87-2.21) (2,27-2.68) 1 (2.85-3.17) (3.37-3.99) (4.06-4.83) 1 (4.65-5.56) (5.26-634) (5.92-7.18) (6.84-8.39) (7.63-9.47) 2.19 2.65 3.35 4.00 4.91 5.73 6.60 7.56 8.97 10.2 3-It (2.02-2.40) (2.45-2.91) 1 (3.08-3.67) 1 (3.66-4.38) (4.47-5.36) (5.17-6.24) (5.91-7.19) (6.71-8.24) (7.87-9.79) (8.88-11.2) 6-hr 2.67 (2.44-2.94) 3.23 (2.96-3.57) 4.09 1 (3.73-4.',i1) 4.89 (4.45-5.39) 6.02 1 (5.44-6.62) 7.03 (6.30-7.73) 8.13 (723-8.92) 9.35 (8.23-10.3) 11.2 (9.68-12.2) 12.8 (11.0-14.1) 3.14 3.81 4.84 5.83 7.22 8.49 9.88 11.4 13.8 15.9 12-hr (2 ,85-3.50) (3.45-4.24) (4.38-5.39) (5.25-6.48) (6.45-8.0) (753-9.39) (8.68-10.9) (9.94-12.6 ) ( 11.8-15.2) ( 13.4-176) 24-It 3.59 (3.29-3.96) 4.36 (4.00-4.82) 5.64 (5.17-6.22) 6.75 (6.15-742) 8.40 (7.59-9.23) 9.85 (8.81-10.8) 11.5 (10.1-12.6) 13.3 (11.6-14.6) 16.0 (13.7-17.7) F18.4 (15.5-20.4) 3 2 2-tlay (3.81-4.62) 4.6105.59 5: 0-7.17 7.0�8.53 8.63610.E 10.0'12.4 115-14.5 132516s 15B 0.4 1761.0.E 4.43 5.35 6.83 8.09 9.97 11.6 13.4 15.4 18.4 21.1 3-day (4.05-4.87) (4.89-5.90) (6.23-752) (7.35-8.90) 1 (8.99-11.0) 1 (10.4-12.7) (11.9-14.7) (13.5-17.0) (15.8-20.5) (17.8-23.6) 4.67 5.65 7.17� 8.45 10.3 11.9 13.7 15.E 18.6 21.2 4-day (4.28-5.13) (5.17-6.21) (6.55-7.38) (7.70-9.27) 1 (9.34-11.3) 1 (10.7-13.1) (12.2-15.0) (13.7-17.2) (16.1-20.6) (18.0-23.6) 5.43 6.54 8.22� 9.62 11.E 13.3 15.2 17.1 20.0 22.4 7-day (5.00-5.93) (6,02-7.14) (7.55-8.97) (8.80-10.5) 1 (10.6-12.7) 1 (12.1-14.5) (13.6-16.6) (15.2-18.8) (17.5-22.1) (19.3-24.8) 6.08 7.29 9.04� 10.5 12.6 14.3 16.2 18.2 21.1 23.4 10-day (5.62-6.64) (6.73-7.95) (8.32-9.85) (9.62-11.4) (1L5-13.7) (13.0-15.6) (14.6-17.6) (16.2-19.9) 1 (20.3-26.0) 20-day 8.13 (7.56-8.77) 9.68 1 (9.00-10.4) 11.8 1 (10.9-12.7) 13.5 1 (12.5-14.6) 16.0 1 (14.7-17.2) 18.0 1 (16.5-19.4) 20.1 (18.3-21.7) 22.4 (20.1-24.3) 25.5 (22.7-27.9) 88.1 (24.7-30.9) 9.97 F11.8 14.2� 62 18.8 21.0 23.1 25.4 28.5 30.9 30-d7y (9.33-10.7) (11.1-12.7) (13.3-1;i.3 (15.1-17.3) 1 (175-20.2) 1 1 (21.3-24.9) (23.2-27.4) (25.7-30.9) (27.6-33.7) 12.5 14.8 17.6 19.9 33.1 25.7 28.4 31.2 35.0 38.0 45-dey (11.7-134) 1 (13.8-15.9) 1 (16.4-18.9) 1 (18.6-21.4) 1 (21.5-24.9) 1 (23.8-27.7) (26.1-30.6) (28.4-33.7) (31.5-38.0) (33.9-41.5) 15.1 17.8 21.0� 23.5 26.9 29.E 32.3 35.0 38.E 41.4 60-day Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90%confidence interval. The probability that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates al upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more informalion. Back to Too http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=34.7019&Ion=-77.4309&dot... 12/14/201 1 Precipitation Frequency Data Server Page I of 4 NOAA Atlas 14, Volume 2, Version 3 �...,� Location name: Jacksonville, North Carolina, US" h Coordinates 19,-77.4309 i t Elevation: ion: 19ft' ' source: Google Maps !„ ,,.� POINT PRECIPITATION FREQUENCY ESTIMATES G.M. gastrin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. li NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF oraohical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90%confidence intervals (in inches/hour)' Average recurrence interval(years) Duration ���� 10 25 50 100 200 500 1000 5.88 6.94 8.03 9.01 10.2 11.1 12.0 12.9 14.1 15.1 5-min (545-6.38) (6.42-7.51 ( 7.42-8691 8.30-974) 9.32-11.0 ( 10.1-12.0 ( 10.9-13.0) (11.7-140) 12.6-15,3) 133-16.4 4.70 5.54 6.43 7.21 8.11 8.83 9.53 10.2 11.1 11.9 10-min 4.35-5.09 (5.14-6.01) 1 (5.93-6.95) 1 t6.64-7.79) 7.43-8.75) 1 (8.06-9.53) 1 (8.66-/03) 1 (923-11.1) 9.94-12.1) 10.5-12.9 3.92 4.65 5.42 6.08 6.85 7.46 8.04 8.61 9.34 9.93 15-min (3.62-4.25) (4.30-5.03) 1 (5.00-5.86) (5,60-6.57) 1 (6.28-7.39) 1 (6.81-8.05) (7.30-8.68) (7.77-9.31) 1 (8.34-10.1) (8.79-10.8) 2.68 3.21 3.85 4.40 5.07 5.61 6.15 6.70 7.43 8.04 30-min (2.48-2.91) (2.97-3.47) (3.56-4.17) 4.06-4.76) 4.65-547) 513-6.06) (559-6.65) (6.05-7.25) 1 (6,64-806) 7,12-874 1.67 2.01 2.47 2.87 3.38 3.80 4.24 4.70 5.33 5.87 60-min (1.55-182) (186-2.18) (228-2.67) (264-3.10) (310-3.65) (347-4.11) (385-4.58) (4.24-5.08) 1 (4.76-5.78) (5.20-638) 1.02 1.23 1.55 1.84 2.22 2.56 2.92 3.31 3.86 4.34 2-hr (0.936-1.11) (1.14-1.34 (lA2-1.68) (1.68-2.00) (2.03-2.41) (2.32-2.78) (2.63-3.17) (2.96-3.59) (3.42-420) ( 3.82-4.74 0.729 0.884 1.12 1.33 1.64 1.91 2.20 2.52 2.99 3.41 3-hr (0.671-0.800) (0.814-0.969) (1.03-1.22) 1 (1.22-1.46) 1 (1A9-1.79) 1 (1.72-2.08) 1 (1.97-2.39) 1 (2.24-2.74) 1 (262-3.26) 1 (2.96-3.73) 0.445 0.539 0.682 0.817 1.01 1.17 1.36 1.56 1.86 2.13 6-hr 0.408-0.491) (0.494-0.596)1(0.622-07E6)1(0.743-0.900 (0908-1.11) (1.05-129) 1(1.21-1.49 (1.38-1.71) 1.62-2.05) 1.83-2.35 12-hr (0.2372Q290) (0.28630352) (0.364 OA47) (0.435--0538) (0.535-0664) (0.625--0779) (0.72180906) (0.82541105) (0.978-1.26) (1.1113246) 235 768 24-hr 0.137-0.1165 (0.167-0201 (0.2105-02!i� 0.256-0.309) 0.310630384) (036 -0.450 (0.423-0524 OA84-O608) 0.5702-0737) 0s47-0652) 0.087 0.105 0.135 0.161 0.200 0.234 0.273 0.316 0.381 0.438 2-day (0.079-0.096) (0.096-0.116)1(0.123-0.1 J9 0.146-0.178) 0.180-0.221) (0.209-0.259) (0.240-0.301) (0.274-0.350) 0.325-0A24) 0.367-0.491) 0.061 0.074 0.095 0.112 0.138 0.161 0.186 0.214 0.256 0.293 3-day (0.056-0.068) (0.068-0.082) (0.086-0.105) (0.102-0.124) (0.125-0.152) (0.144-0.177) (0.165-0205) (0.187-0.236) (0.220-0.285) (0.247-0.328) 0.049 0.059 0.075 0.088 0.108 0.124 0./43 0.163 0.194 0.221 4-day 0.045-0.053) (0.054-0.065 (0.068-0.092 0.080-0.097) 0.097-0.118) (0.112-0.136)1(0.127-0.157)1(0.143-0.179) 0.167-0.215) 0.188-0246) 0.032 0.039 0.049 0.057 0.069 0.079 0.090 0.102 0.119 0.133 7-day (0.030 0.035) (0.036-0.042) (0.045-0.053) (0052-0.062) (0.063-0075) (0,072-0.086) (0.081-0.099) (0.090-0.112) (0.104-0.131) (0.115-0.148) Y(0.023 0.030 0.044 0.052 0.060 0.067 0.076 0.088 0.098 1F00.025 Od 0.028) (0.028-0.033) .038 (0.035-0.041) (0.040-0.048) (0.048-0.057) (0054-0.08) (0.061-0.074) (0.067-0.083) (0.077-0.097) (0.085-0.108) 0.017 0.020 0.025 0.028 0.033 0.037 0.042 0.047 0.053 0.059 20-day (0.016 0.018) (0.019-0.022) (0.023-0026) (0.026-0.030) (0.031-0.036) (0.034-0.040) (0038-0045) (0.042-0.051) (0.047-0.058) (0.051-0064) 0.014 0.016 0.020 0.022 F 0.026 F 0.029 0.032 0.035 F 0.040 0.043 30-day (0.013-0.015) (0015-0018) (0018-0021)1(0.021-0.024) 0.024-0.028) (0.027-0031) (0030-0035) (0032-0.038) (0.036-0.043) (C.038-0.047) 0.012 0.014 0.016 0.018 0.021 0.024 0.026 0.029 0.032 0.035 45-day (0.011-0.012) (0.013-0015) (0.015-0.018) (0.017-0.020) (0.020-0.023) (0.022-0.026) (0.024-0028) (0.026-0.031) (0.029-0.035) (0.031-0.038) 0.011 0.012 0.015� 0.016 0.019 0.021 0.022 0.024 0.027 0.029 60-day (13.010-0.011) (0.012-0.013 (0.014-0.(116 (0.015-0.017) (0.017-0.020) (0.019-0.022) (0.021 -0.024 (0.022-0.026 0.024-0.029) 0.026-0.031) Precipitation frequency rl') estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probadliry that precipitation frequency estimates (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid Phil values. Please refer to NOAA Atlas 14 document for more in`ormation. Back to Top hitp://hdsc.nws.noaa.gov/hdsc/p1'ds/pfds_printpage.html?lat=34.7019&Ion=-77.4309&dat... 12/ 14/201 1 I Rational Method for Swale SF-2A + SF-2B I Use Rational Method to calculate peak discharge: Q = c * i * A Composite "c" factors: +Area` ac ` "c" Description 1A2 0.95 Impervious 1.40 0.15 Lawns, heavy soil, flat <2% 0.00 1 0.30 ILawns, heavy soil, steep >7% 0.55 - runoff coefficient 7.210 in./hr. - rainfall intensity for 10-yr peak runoff (10 min Tc) 2.83 acres - Northside Perimeter Road parallel of R/W 05/23 peak discharge, Qpeak = 11.26 cfs Rational Method for Swale SF-4 I Use Rational Method to calculate peak discharge: Composite "c" factors: Q= c*i*A Area; ac - ','c" IDescription 1.52 1 0.95 jImpervious 0.98 1 0.15 1 Lawns, heavy soil, flat <2% 0.00 1 0.30 Lawns, heavy soil, steep >7% c = 0.64 - runoff coefficient i = 7.210 in./hr. - rainfall intensity for 10-yr peak runoff (10 min Tc) A = 2.49 acres - Southside Perimeter Road parallel of R/W 05/23 peak discharge, Qpeak = 11.43 cfs Rational Method for Swale Redev Use Rational Method to calculate peak discharge: Q = c * i * A Composite "c" factors: .Area: ac V'. ; IDescription 0.42 0.95 jImpervious 3.80 0.15 Lawns, heavy soil, flat <2% 0.00 1 0.30 Lawns, heavy soil, steep >7% 0.23 - runoff coefficient 7.210 in./hr. - rainfall intensity for 10-yr peak runoff (10 min Tc) 4.22 acres - Eastside Perimeter Road parallel of West R/W 01/19 peak discharge, Qpeak = 699 cfs Hi(]h Density`,: Swale SF=2A +`Swale`SF-2B Peak discharge using Rational Method for 10-yr / 10-min storm event Qpeak = 11.26 cfs The use of this Grassed Swale does NOT seek treatment credit. 0.035 0.50 � IRWS(ft) 3.0 tr f FTSNft) 3.0 Q;'.cfs" 11.26 Calculate'df SWALE CHARACTERISTICS r Tw Q F.s Ia� B s I a.w -{ Tw = (F.S. x df)+ B.W . + (B.S. x df COMPARISON BETWEEN R"'xA's 2/3 R (J 2/3 x A4f — R x A o.001 OKAY shall be less than or equal to 0.001 Flow depth at swale ;1.02. ; ft VELOCITY 2 V_1.49x�vvp aw�'x(S f2 1 /00 wp = Wetted perimeter, ft aw = Cross sectional area based on depth of flow, ft2 bw = bottom width of swale, ft S = Constructed slope,`% n = Manning's formula V = Velocity at swale, fps 2t7§ tt : fps High Density Swale SF-4 Peak discharge using Rational Method for 10-yr / 10-min storm event Qpeak = 11:43 ; cfs The use of this Grassed Swale does NOT seek treatment credit. .n 0.035 0.50 2.0 3.0 3.0 11.43 Calc'ulate;df, SWALE CHARACTERISTICS �- �T w -� F.S. Ian B.S. t L B.W. Tw = (F.S. x df )+ B.W . + (B.S. x df COMPARISON BETWEEN R2/3XA's 2/3 �/3 Rdf x Adf — R X A 0.001 OKAY shall be less than or equal to 0.001 Flow depth at Swale: .T:1:A3�ft VELOCITY V 1.49 x �vvp aw )i3 z 1 100J wp = Wetted perimeter, ft aw = Cross sectional area based on depth of flow, ftz bw = bottom width of swale, ft S = Constructed slope,% n = Manning's formula V = Velocity at swale, fps 2 18, , fps Peak discharge using Rational Method for 10-yr / 10-min storm event Qpeak = 6.99 cfs The use of this Grassed Swale does NOT seek treatment credit. x Brix` 0.0" 1.00 B*W (ft•) 2.0 B S(ff) 3.0 3.0 Q 6f§491 6.99 SWALE CHARACTERISTICS Tw F,S. �di"� B.S. i— B.w, -{ Tw = F.S. x df )+ B.W . + B.S. x df COMPARISON BETWEEN Rz13xA's 2/3 2�/3 Rdf x Adf — R x A o.001 OKAY shall be less than or equal to 0.001 Flow depth at swale: ft VELOCITY V _ 1.n9 (wp awl 'v2 J �100 wp = Wetted perimeter, ft aw = Cross sectional area based on depth of flow, ft2 bw = bottom width of swale, ft S = Constructed slope,"/o n = Manning's formula V = Velocity at swale, fps 2r:47 fps STORM SEWER TABULATION .• ;PROJECT.60 0510112012 r PROJECT:Development 1 Des • Storm •• p - - Avenue - r 904.357.4271 c o w u a m a E s a c Drainage Area (ac) Time of Tc Flow in Section m TOTAL = (C-A) (ph) O o ELEV.of H.G. A Crown EL. m Flow Line EL. y Upper Lower FALL r 2; E o n o N ,u'11 o j n tj Notes C- 0.95 SUB Total (CA) _ m r C= 0.15 BASIN SF4 C= 0.30 UP Incre- ment SUB Total DOWN (feet) (min.) (min.) (cfs) (feet) (feet) (feel) (feet) (in.) N (fps) (cfs) Remarks Bypass WS ST-3 67 0.23 1.24 1,18 15.58 0.17 6.02 1.28 7.69 18.25 77.00 0.07 24 RCP 0.10 2.45 7.69 Minor Loss= 0,00 0.22 0.66 0.10 16.00 15.50 0.50 Loss Coef. = 0.00 BMP SF-1 0.00 0.00 0.00 14.00 13.50 0.50 0.75 6.74 21.17 Clearance = 11.13 Inlet ST-4 90 0.23 0,76 0.74 15.32 0.26 6,04 0,77 4.68 18.40 1722 17.07 0.15 18 RCP 0,17 2.65 4.68Minor Loss= 0.00 0.22 0.22 0.03 1625 15.50 0.75 Loss Coef. = 0.00 Inlet ST-3 0.00 0.00 0.00 14.75 14,00 0,75 0.83 5.88 1039Clearance= 1118 Inlet ST-5 97 0.55 0.551 O.521 15.00 0.32 6,08 0.52 3.18 18.76 17,42 17.221 0.201 15 RCP 0.21 2.59 3.18 Minor Loss = 0.00 0.00 0.00 0.00 1675 i6.00 0.75 Loss Coef. = 0,00 Inlet ST-4 0.0o 000 0.00 15,50 14,75 0.75 0.77 5.01 6.15 Clearance = 7.34 Inlet ST-6 143 0.23 0.23 0.22 15.00 0.50 6.08 0.25 1.53 19.00 17.49 17.42 0.07 15 RCP 0.05 7.25 1.53 Minor Loss = 0.00 0.22 0.22 0.03 17.25 16.25 1.00 Loss Coef. = 0.00 Inlet ST-3 0.00 0.00 0.00 16.00 15.00 1 00 0.70 4.77 5 85 Clearance = 1.51 �ST-3 (BYPASS STRUCTURE) WEIR ELEVATION MH ST-2 53 0.00 0.00 0,00 15,76 0.23 5.99 0,00 8.69 18,75 6.57 5.75 0.82 15 RCP 1.54 7.08 6.69 Minor Loss = 0,00 0.00 0.00 0.00 6,00 5.75 0,25 Loss Coef. = 0.00 outfall OUT 0.00 0.00 0.00 4.75 4.50 0,25 0.47 3.92 4.81 Clearance = 12.18 Bypass D/S ST-3 10 0.00 0.00 0.00 15.74 0 02 6.00 0.00 8.69 18.25 17.22 17.07 0.15 15 RCP 1.54 7.08 8.69 Minor Loss = 0.00 0.00 0.00 0.00 12.75 12.50 0.25 Loss Coef. = 0.00 MH ST-2 0.00 0.00 0.00 11.50 t1.25 0.25 2.50 9.02 11.06 Clearance AS zlm P 1) AVVJ /"A"` STORM SEWER TABULATION .• -. r r 6 f r (feet) r Drainage Area (ac) C= 0.95 0.15 SUB 0.30 Total SUB (CA)DOWN ment Total -. Tc (min.) Time of Flow In Section (min.) Z' iTOTAL (iph) (D•A) Design O a o r (cfs) Deife Storm. oELEV. n m n (feet) lopment CrowC= Flow L Upper LoUPIncre- (feet) (fs) =(in.)(%) 111 Riverside Avenue - r 'r• m a m 3 a NC= eL Notes BASIN SF-2 (cfs) IRemarks Bypass UIS ST-10 34 0.06 1.79 1.70 15.60 0.12 6.01 2.07 1246 16.00 13.00 1.08 15 RCP 3.17 10.16 12.46 Minor Loss = 0.00 0.52 2.48 0.37 11.50 11.25 0.25 Loss Coef. = 0.00 BMP ST-8 0.00 0.00 0.00 10.25 10.00 0.25 0.74 4.89 6.00 Clearance Inlet ST-17 180 1.42 1.42 1.35 15.00 0.60 6.08 1.56 9.48 /4.25 1 14.35 14.08 0.27 24 RCP 0.15 3.02 9.48 Minor Loss = 0.00 1.40 140 0.21 13.00 12.25 0.75 Loss Coef. = 0.00 ._.Inlet. _ ST-10 0.00 0.00 0.00 11.00 00.25 0.75 0.42 5.06 15.82 Clearance = -0.10 Inlet ST-14 114 0.31 0.31 0.29 15.00 0.41 6.08 0.38 2.30 i600 14.20 14.08 0.12 15 RCP 0.11 1.88 2.30 Minor Loss = 0.00 0.56 0.56 0.08 12.25 7L50 0.75 Lass Coef. = 0.00 Inlet ST-10 0.00 0.00 0.00 11.00 70.25 0.75 0.66 4.63 5.68 Clearance = 1.80 �ST-10 (BYPASS STRUCTURE) WEIR ELEVATION Bypass DIS ST-10 55 0.00 0.00 0.00 0.00 0.24 I 7.76 0.00 12.46 1 16 00 12.99 11.25 1,74 15 RCP 3.17 10A6 12.46 Minor Loss = 0.00 0.00 0.00 0.00 11.50 11.25 0.25 Loss Coef. = 0.00 outfall I ST-9 1 0.001 0.00 0.00 1 10251 10.001 0.25 1 0.451 3.841 4.72 Clearance = 3.01 77t.n7 P n JVVJ STORM SEWER TABULATION BY'TML DATE: 05/012012 PROJECT: MCAS New River MV-22 Hangar Development Has. Architects 111 Riverside Avenue and Engineers PROJECT No.: 6601220 10-yr 115-min Storm Tabulations (Equivalent Design Storm for 1.5" Runoff Depth) Jacksonville Florida 32202 PH: 904.357.4271 c 3 m r m ° mI 3 n ` rn urainage wrea C= 0.95 rn C= 0.15 1 C= 0.30 Incre- SUB lacl Time oL Tc Flow iTOTALg o Sectio(C`A) r KnnwN '- Crown EL. Flow Line EL.5! a Upper Lower FALL 'o >N SUB Total (CA) UP Ifoml --f Total 1min.I Imin.l Icfsl Ifeetl ffeetl Ifeell (feet) IinJ 1%1 Ifpsl Ich UIS ST-20 24 0.00 0.00 0.05 15.13 0.04 6.07 0,28 /6A6 19.00 14.35 14.00 0.35 24 RCP Loss Coef. = 0.00 BMP ST-19 0.00 0.00 0.00 12.35 12.00 0.35 1 46 9,42 29.60 Clearance Inlet 0.24 ST-21 63 0.35 0.24 0.23 15,00 0.13 6.08 0,28 14A6 17.35 15.32 15.10 0.22 24 RCP 0.35 4.fi0 14.46 Minor Loss = 0.00 0.35 0.05 15.00 14.35 0.65 ILoss Cost. = 0.00 0.00 0.00 13,00 12.35 0.65 1.03 7.92 24.89 Clearance 12.03 �ST-20 (BYPASS STRUCTURE) WEIR ELEVATION MH ST-16 89 0.00 0.00 0.00 16.48 0.30 5.91 0.00 18.16 15.50 10.99 10.50 0.49 24 RCP 0.55 5.78 18,16 Minor Loss= 0.00 0.00 0.00 0.00 9.85 9.50 0.35 Loss Coal. = 0.00 outfa11 ST-15 0.00 0,00 0.00 7.85 7.50 0.35 0,39 4,89 15.37 Clearance = 0.51 MH ST-17 153 0.00 0.00 0.00 15.85 0,63 5.98 0.00 17.16 15.50 14,47 10.99 3.48 18 RCP 2,27 9.71 17,16 Minor Loss= 0.00 0.00 0.00 0.00 9.95 9,35 0.60 Loss Cast. = 0,00 MH ST-16 0.00 0.00 0,00 8.45 7,85 0.60 0,39 4,03 7.13 Clearance 11.03 MH ST-18 132 0.00 0.00 0,00 15.32 0.53 6.04 0.00 17.16 19.00 1747 14.47 3.00 18 RCP 2.27 9.71 17.16 Minor Loss = 0.00 0.00 0.00 0,00 10.50 9.95 0.55 Loss Coat. = 0.00 MH ST-17 0.00 0.00 0.00 9.00 8.45 0.55 0.42 4.16 7.35 Clearance = 1.53 Bypass D/S ST-20 142 0.00 0.00 0.00 15.00 0.32 6.08 0.00 16.16 19.00 17.97 15.10 2.86 18 RCP 2,02 9.15 16.16 Minor Loss= 0.00 0.00 0.00 0.00 13.85 12.00 1.85 Lass 0.00 MH ST-18 0.00 0.00 0.00 12.35 10.50 1.85 1.30 7.35 12.99 Clearance = 1.03 =�j STORM SEWER TABULATION BY: TML Architects and Engineers DATE: PROJECT 05/01/2012 No.: 6601220 10-yr / 15-min PROJECT: MCAS New River MV-22 Hangar Storm Tabulations (Equivalent Design Development Storm for 1.5' _Haskell - Runoff Depth) 111 Riverside Jacksonville Florida Avenue 32202 PH: - 904.357.4271 y a D rainage Area (ac) V o i 3 a C= 0.95 Time of m c o m ° E m c C= 0.15 SUB Tc Flow in m TOTAL m m i0 y z C= 0.30 Total Section (C-A) f n w UP Incre- SUB (CA) 0 h DOWN (feet) ment Total (min.) (min.) (ph) (cfs) (feet) Bypass 1.52 1.52 1.44 U/S ST-25 112 0.98 0.98 0.15 15.00 0 33T 6.08 1.69 967 14A Crown EL. i` 6' Flaw Line EL. E o o n r Lower FALL O h j 12..60 1200.0.60 P0610.000RC 0.54 5.7t 17 ®ST-25 (BYPASS STRUCTURE) WEIR ELEVATION Bypass D/S ST-25 160 0.00 0.00 0.00 0.00 0.31 7.76 0.00 1 9.67 14A0 12.16 11.00 1.16 18 RCP 0.72 5.47 9.67 Minor Loss = 0.00 0.00 0.00 0.00 12.10 9.25 2.85 Loss Coef. = 0.00 outfall ST-231 0.001 0001 0.00 1 10.601 7.751 2,851 1 1.781 8.591 15.19 Clearance = 11.94 7Vq STORM SEWER TABULATION .• -. r f r 66012261Design - Storm. . - - r 90 2 h r .�, a s c Drainage Area (ac) Time of Tc Flow in Section O uTOTAL �ca = (C'A� r oELEV. of H.G. m o Coj lRemarks Notes C= 0.95 SUB Total (CA) A Crown EL. C= 0.15 Flow Line EL. E BASIN EAST OF SF3C= 0.30 n Upper �°DOWN Lower FALL o UP Incre- ment SUB Total (feet) (min.) (min.) (iph) (cfs) (feet) (feet) (feet) (feet) (in.) (%) (fps) Ex. C.I. south 150 0.16 0.32 0.30 15.36 0.34 6.04 0.68 4A 1 14.54 17.67 14.80 12.80 14.50 0.04 24 RCP 0.03 1.31 4.11 Minor Loss = 0.00 O.fiO 2.51 0.38 1347 1.33 Loss Coef. = 0.00 EW OUT 0.00 0.00 0.00 it47 1.33 0.89 7.35 23.08 Clearance = 3.13 " - -- Ex. C.I. north =C.I.nonhEx. 30 0.09 0.16 0.15 15.2 00.10 6.05 0.44 2.65 14.56 1T66 14.61 13.11 14.54 0.02 18 RCP 0.05 1.50 2.65 Minor Loss = 0.00 0.07 1.91 0.29 14.42 0.19 Loss Coef. = 0.00 Ex, C'.i.. South 0.00 0.00 0.00 12.92 0.19 0.63 5.12 9.06 Clearance = 3.10 Ex. C.I. east 86 0.07 0.07 0.07 15,00 0.26 6.08 0.10 0.61 14.57 17.64 15.16 13.91 14.56 0.01 15 RCP 0.01 0.50 O.fit Minor Loss = 0.00 0.23 0.23 0.03 14.36 0.80 Loss Coef. = 0.00 Ex. C.I. north 0.00 0.00 0.00 13.11 0.80 0.93 5.50 6.75 Clearance = 3.07 M.E.S. ST-22 26 0.00 0.00 0.00 15.00 0.04 6.08 0.24 1.47 1457 14.50 15.75 14.50 14.56 0.01 15 RCP 0.04 1.20 1 47 Minor Loss = 0.00 1.61 1.61 0.24 1500 0.75 Loss Coef. = 0.00 Ex. C.I. I north 0.00 0.00 0.00 13.75 0.75 2.88 9.69 11.89 Clearance ZLn7 e XV:" �' .Z l 2012 06 addinfo 091113 From: Lewis,Linda Sent: Wednesday, June 06, 2012 9:05 AM To: 'Luman, Travis M.' Cc: Russell, Janet subject: FW: sw8 091113 Mod. (MV-22 Hangar & Pov Parking Garage) - Followup Travis - The underdrain calculations need to be redone as well. I don't know exactly why, but I am coming up with much larger minimum underdrain diameters even though I am using the same equation that you do. Fortunately, you have specified enough underdrains in each case to accommodate the expected flow through the sand filter media, but I think the calculation of the minimum underdrain diameter needs to be correct. I think the problem may be in the slope - I see that you use 0.5%, but the equation needs the slope to be in feet per foot, so it should be .005. Are you entering 0.5 in the equation or .005? I still haven't heard back from my advisory group on the sand filter volume error yet, but as soon as I do, you'll be first in line. Linda Lewis NC Division of water Quality 127 Cardinal Drive Ext. Wilmington, NC 28405 910-796-7215 E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third parties. From: Lewis,Linda Sent: Tuesday, June 05, 2012 12:58 PM To: 'Luman, Travis M.' Cc: Russell, Janet subject: Sw8 091113 Mod. (Mv-22 Hangar & Pov Parking Garage) Travis: The revised calculations must be signed, sealed and dated. The Rainwater Harvesting system (RHS) calculations that you submitted are not what I am looking for. They appear to be based on a 1" design storm. Essentially, I need to see your calculations (via the simple method) of the required minimum volume to capture based on a 1.5" design storm, and whatever the roof BUA is (DA at 100% impervious) that is being directed to that RHS. I am concerned that the up -front filtering will cause the incoming flow to slow down, resulting in much more bypassing to the infiltration basin. Did you tell me before that you weren't claiming any volume credit for the RHS and that all of the runoff volume had been accounted for in the infiltration basin? If that's true, then I don't need anything else. But, if you are Page 1 2012 06 addinfo 091113 claiming any of the volume credit for the RHS, then i will need to see those calculations. Please include the location of the bypass line in the schematic details you provided. I am looking into an error in the BMP Manual for the volume provided in the sand filter (vertical box only). Essentially, the volume provided in a vertical box sand filter is only what is above the sand surface on the sand side up to the external overflow weir, and what is above the internal weir elevation on the sediment side up to the external overflow elevation. when runoff enters the sediment chamber, the volume below the weir into the sand chamber will never be able to drain into the sand chamber, so that volume cannot be included as part of the.provided volume. The BMP Manual, however, just uses Fimax multiplied by the sum of the two chamber surface areas to determine the volume provided. when I get it resolved, I will be back in touch. Linda Lewis NC Division of Water Quality 127 Cardinal Drive Ext. Wilmington, NC 28405 910-796-7215 E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be disclosed to third parties. Page 2 -NASKEL® HASKELL tel 904.791-4500 �� I I I Riverside Avenue fax 904.791.4699 ARCHITECTS AND ENGINEERS, P.A. Jacksonville, Florida 32202-4950 web www.haskell.com TO: Ms. Linda Lewis NCDENR Wilmington Office 127 Cardinal Drive Extension Wilmington, North Carolina 28405 PROJECT: MV-22 Hangar Complex Development MCAS New River Jacksonville, North Carolina 6601220 We are sending you ® herewith ❑ under separate cover DATE: May 21, 2012 Transmittal SUBJECT: NCDENR High Density RAI 1 Package f of 1 S60Y0g1/ 13 the following documents on this project. NUMBER COPIES I DRAWING NUMBER DATED TITLE OR DESCRIPTION PREPARED BY 2 multiple 5/21/12 I CJ-002, 003, & 005-009 — Haskell CK-002, 003, & 005-009 CS-002, 004, 006-011, & 021 a CG-002, 004, 006-011, 021, 513 & 514 _ 1 --_-__,____. 5/21/12 --- -- — --- --t ---- Revised Sand Filter Supplements with requested - ell Haskell corrections � 1 5/21/12 Revised pages from ReportIncluding Underdraln I Haskell _ _Pipe Sizing calculations 1 5/21/12 _ i A,erial Map with High Density Project Area Haskell I delineated__ 1 P-701_ 5/8/12 _ Rainwater Harvesting Diagram Haskell 1 3/22/12 Rainwater. Harvesting Modeling Calculations ' Wahaso 1 — - -� 5/21/12 J Ftesponses to Comments (RAI 1) — _ —Haskell These documents are being submitted to you: ❑ For your use. ❑ Please sign and return both copies; one executed copy will be returned to you ❑ For estimating purposes. For your approval. Please return (1) copy "APPROVED" or, "APPROVED AS NOTED". ❑ Approved. [] Dueto revisions. Please acknowledge receipt, advising if these revisions will affect the ❑ Approved as noted. contract price. ❑ For REMARKS: COPIESTO: Mr. Thomas Bradshaw- MCB Public Works Mr. Kenneth J. Boeser Ms. Myra W. Jones Mr. Michael R. McCarthy Mr. Larry W. Willis Very truly yours, HASKELL ARCHITECTS AND ENGINEERS, P.A. Travi M. Luman, P.E. Civil Engineer +HASKELL ARCHITECTS AND ENGINEERS, P.A. Ms. Linda Lewis NC Division of Water Quality 127 Cardinal Drive Ext. Wilmington, North Carolina 28405 910-796-7215 Dear Ms. Lewis: HASKELL ref 904791-4500 111 Riverside Avenue fax 904:791.4699 Jacksonville. Florida 32202-4950 web www.haskell.com May 21, 2012 Re: MV-22 Aviation Complex Jacksonville, North Carolina Please see Responses to your Comments as provided below: Comment 1: Please check and add elevations and dimensions to the sand filter detail SF-1. There is very limited elevation information and using the dimensions provided to figure out the elevations does not result in the same elevations as are reported on the supplement form. The elevations listed in the "Detail' column below were obtained from the dimensions and elevations provided in Sections A and B: Detail Supplement Weir elevation between the chambers 13.5 16.0 Top of Sand Elevation 11.5 14.0 Bottom Elevation 10.0 11.0 Internal Bypass Elevation 18.0 n/a External Bypass Elevation 17.07 n/a Response 1: Dimensions and elevations have been added to the details as requested. The Supplement has been revised to include the correct information as well. The correct numbers from the column above are: 16.0, 14.0, 12.5, 17.0 and 17.07, respectively. Comment 2: From the data above:, if the external bypass elevation is 17.07 as indicated for ST- 3 on sheet CG-514, then the internal bypass elevation cannot be higher. The internal bypass elevation needs to be equal to or less than the external bypass elevation. Response 2: Internal bypass elevation corrected to be 17.0. External bypass elevation remains at 17.07 due to hydraulic head calculations. Comment 3: The top elevations listed on the supplements for SF-2, SF-3 and SF-4, are each one foot lower than the top elevation shown on the details on sheet CG-513. Please correct to be consistent. _ r2r�C�IVE,:: Response 3: Corrected on each Supplement. L01Z MAY 2 2 i3 4/ HASKELL ARCHITECTS AND ENGINEERS, P.A. HASKELL tel 904.791-4500 111 Riverside Avenue fax 904.791.4699 Jacksonville, Florida 32202-4950 web www.haskell.com Comment 4: Please report the actual volume provided at the internal weir elevation on the supplement forms for SF-2, SF-3 and SF-4. The provided volume calculation in the BMP manual of [(Af + As) x hma„] assumes a vertical sided chamber. You have open basins with a 3:1 side slope, so there will be more volume provided than you have reported on the supplement. Response 4: Corrected on each Supplement and revised in the discussion portions of the Report as well. Comment 5: Please provide underdrain sizing calculations per the requirements and design procedures listed in section 5.7 of Chapter 5 of the BMP Manual, Common BMP Design Elements. Response 5: Provided in the discussion portions of the Report. Flow rate as shown on each Supplement remains as reported. Comment 6: Please provide Rainwater Harvesting System calculations, plans and details. Response 6: Plumbing Sheet P-701 is provided to show the Rainwater Harvesting Diagram. Modeling calculations provided by Wahaso are included as well. Thank you for your time and assistance on this project. Respectfully, Travis M. Luman, P.E. tml CC: Thomas Bradshaw, MCB Public Works File :MAY 2 2 .Z01Z Lewis,Linda From: Lewis, Linda Sent: Tuesday, May 15, 2012 12:28 PM To: 'Luman, Travis M.' Cc: Russell, Janet; Bradshaw CIV Thomas C Subject: 2012 05 addinfo 091113 Attachments: 2012 05 addinfo 091113.pdf Attached are my Express review comments for SW8 091113. Linda - NC®ENR North Carolina Department of Environment and Natural Resources Beverly Eaves Perdue Governor May 15, 2012 Commanding Officer MCB Camp Lejeune c/o Carl Baker, P.E., Deputy PWO Building 1005 Michael Road Camp Lejeune, NC 28547 Division of Water Quality Charles Wakild, P. E. Director Dee Freeman Secretary Subject: Request for Additional Information — Express Review Stormwater Project No. SW8 091103 Mod. P688 Apron Expansion) Ph. 11, P683/P687 MV-22 Hangar Development Onslow County Dear Mr. Baker: The Wilmington Regional Office received an Express State Stormwater Management Permit Application for P688 Apron Expansion Ph. II, P683/P687 MV-22 Hangar Development on May 4, 2012. A preliminary review of that information has determined that the application is not complete. The following information is needed to continue the stormwater review: Please check and acid elevations and dimensions to the sand filter detail SF-1. There is very limited elevation information and using the dimensions provided to figure out the elevations does not result in the same elevations as are reported on the supplement form. The elevations listed in the "Detail' column below were obtained from the dimensions and elevations provided in Sections A and B: Detail Supplement Weir elevation between the chambers 13.5 16.0 Top of Sand Elevation 11.5 14.0 Bottom Elevation 10 11.0 Internal Bypass Elevation 18.0 n/a External Bypass Elevation 17.07 n/a 2. From the data above, if the external bypass elevation is 17.07 as indicated for ST-3 on sheet CG-514, then the internal bypass elevation cannot be higher. The internal bypass elevation needs to be equal to or less than the external bypass elevation. 3. The top elevations listed on the supplements for SF-2, SF-3 and SF-4, are each one foot lower than the top elevation shown on the details on sheet CG-513. Please correct to be consistent. 4. Please report the actual volume provided at the internal weir elevation on the supplement forms for SF-2, SF-3 and SF-4. The provided volume calculation in the BMP manual of [(At + As) x Hmax] assumes a vertical sided chamber. You have open basins with a 3:1 side slope, so there will be more volume provided than you have reported on the supplement. Wilmington Regional Office 127 Cardinal Drive Extension, Wilmington, North Carolina 28405 DENR 1-877-623-6748 One NorthCaroljna Phone: 910-796-72151 FAX: 910-350.20041 Assistance: Internet: vwvv.ncvvaterquahty.org An Equal Opportunity l Affirmative Action Employer Carl Baker May 15, 2012 Stormwater Application No. SW8 091113 Mod. 5. Please provide underdrain sizing calculations per the requirements and design procedures listed in section 5.7 of Chapter 5 of the BMP Manual, Common BMP Design Elements. 6. Please provide Rainwater Harvesting System calculations, plans and details. Please note that a revision to one number may have a domino effect on other numbers, which may require other revisions to the application, supplements, calculations, plans, details, and associated documentation. Please verify that all numbers are correct to ensure consistency in the application documents. Please note that this request for additional information is in response to a preliminary review. The requested information should be received in this Office prior to May 22, 2012, or the application will be returned as incomplete. The return of a project will necessitate resubmittal of all required items, including the application fee. If you need additional time to submit the information, please mail, email or fax your request for a time extension to the Division at the address and fax number at the bottom of this letter. The request must indicate the date by which you expect to submit the required information. In the Express program, no more than 2 time extensions may be granted, for a total of 10 days. If this is a new project, the construction of any impervious surfaces, other than a construction entrance under an approved Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject to enforcement action pursuant to NCGS 143-215.6A. The proposed modification may not be constructed until the permit modification is approved and the modified permit is issued. Please reference the State assigned project number on all correspondence. Any original documents that need to be revised have been sent to the engineer or agent. All original documents must be returned or new originals must be provided. Copies are not acceptable. If you have any questions concerning this matter please feel free to call me at (910) 796-7301 or email me at linda.lewis(a)ncdenr.gov Sincerely, Linda Lewis Environmental Engineer III GDS/arl: S:\WQS\Stormwater\\Permits & Projects\2009\091113 HD\2012 05 addinfo 091113 CC: Travis Luman, Haskell Architects and Engineers, via email Thomas Bradshaw, MCB via email Wilmington Regional Office Stormwater File Page 2 of 2 4 ASKELL ARCHITECTS AND ENGINEERS, P.A. HASKELL ce1 904.791-4500 111 Riverside Avenue fax 904.791.4699 Jacksonville, Florida 32202-4950 web www.haskell.com To: Ms. Linda Lewis NCDENR Wilmington Office 127 Cardinal Drive Extension Wilmington, North Carolina 28405 DATE: May 3, 2012 Transmittal YR E' CT--TVF' D MAY 0 4 2012 BY: - PROJECT: MV-22 Hangar Complex Development SUBJECT: NCDENR High Density & Low Density MCAS New River Revised sheets Jacksonville, North Carolina Package 2 of 2 6601220 We are sending you ® herewith the following documents on this project. ❑ under separate cover NUMBER COPIES DRAWING NUMBER DATED TITLE OR DESCRIPTION PREPARED BY 2 CK-008 5/3/12 Revised sheets for High Density plan set Haskell CG-008 I CG-009 CG-010 CG-512 CG-513 CG-514 1 5/3112 ; Revised Sand Filter Supplements Haskell 1 j Revised Section IV Drainage Basin Table from High Haskell Density Application Haskell 1 [Revised sheets from Report and Calculations 1 4/16/12 [Review Fee Check 1054220 IMO $4,000 00 I Haskell These documents are being submitted to you: ❑ For your use. ❑ Please sign and return both copies; one executed copy will be returned to you ❑ For estimating purposes. ® For your approval. Please return (1) copy "APPROVED" or, "APPROVED AS NOTED". ❑ Approved. ❑ Due to revisions. Please acknowledge receipt, advising if these revisions will affect the ❑ Approved as noted. contract price. ❑ For REMARKS: The original signed High Density was submitted in person by Thomas Bradshaw from MCB Camp Lejeune on May 1, 2012. COPIES TO: Mr. Kenneth J. Boeser Ms. Myra W. Jones Mr. Michael R. McCarthy Mr. Larry W. Willis =Z-9 cEIVE MAY 0 4 2012 Very truly yours, HASKELL ARCHITECTS AND ENGINEERS, P.A. Travis . Luman, PtEV Civil Engineer E�.#3 CAROLINAf%, "Setting the Standard for Service" . Geotechnical • Construction Materials • Environmental • Facilities NC Re iM..d Enpi .ft Fi,m F-1078 April 12, 2012 Mr. Matthew Gilstrap The Haskell Company 111 Riverside Avenue Jacksonville, Florida 32202 Re: Report of Subsurface Exploration and Geotechnical Engineering Evaluation Addendum P683 MV22 Maintenance Hangar MCAS New River, North Carolina ECS Project No.: 22.17368 Dear Mr. Gilstrap: As requested, ECS Carolinas, LLP (ECS) has completed additional subsurface exploration and laboratory testing for the subject project. This report presents the results of the field exploration and engineering analysis, along with our recommendations for design of geotechnical related items. Subsurface Exploration On February 15, 2012, ECS explored the site by advancing three direct push borings to depths of approximately 12 feet below the existing subgrade at the site. The purpose of this exploration was to obtain subsurface information of the suitability of the in -place soils for the proposed stormwater best management practice (BMP) area. The borings were field located by ECS and observed by representatives of ECS, The Haskell Company, and NCDENR. ECS and NCDENR visually classified the subsurface soils. On March 21, 2012, ECS explored the site pushing three shelby tubes in general accordance with ASTM D 1587 to sample the cohesive soil layers. The tubes were returned to the laboratory for permeability testing. Subsurface Conditions In the upper 5 to 7 feet, the direct push borings encountered grayish brown to tan silty sands, clayey sands and sandy clays. These soils contained redoxamorphic features associated with seasonal high ground water indications. Below 7 feet, the borings encountered tan sand. 7211 Ogden Business Park. Suite 201, Wilmington, NC 28411 • T 910-686-9114 - F: 910-686-9666 - www.eeslimited.com ECS Capitol Services. PLLC - ECS Carolinas, LLP • ECS Florida, LLC - ECS Midwest. LLC • ECS Mid-Allantic, LLC • ECS Southeast. LLC • ECS Texas, LLP Report of Subsurface Exploration and Geotechnical Report —Addendum P683 MV22 Maintenance Hangar MCAS New River, North Carolina ECS Project 22.17368 Groundwater was not encountered at the depths explored. Based on the previously performed subsurface exploration, groundwater in the areas of the direct push borings ranged from 15 to 17 feet below current grades. Due to the clay layer in the upper 7 feet, a perched groundwater conditions exists that create an artificial seasonal high ground water level in the upper 3 feet of the soil profile. If removed, the seasonal high groundwater level is estimated to be 5 feet above the existing groundwater level due to the potential influence of tidal and storm tide influence from the adjacent New River. Laboratory Testing Program A bulk sample obtained during our field exploration was tested in our laboratory to check field classifications and to determine pertinent engineering properties. The laboratory testing program included: • Falling Head Permeability Test (ASTM D5084) All data obtained from the laboratory tests are included in Appendix of this report. Evaluations and Recommendations At the time of the direct push borings, NCDENR determined that an infiltration system would not function properly. NCDENR recommended a sand filter system that could be constructed in the clay without structural concretes provided the clay had an infiltration rate of less than 0.01 inch per hour. Based on the results of the laboratory testing and previous explorations, the existing clays meet the required specifications for sand filter construction. If clay is not encountered in the areas of the sand filter, clay excavated from other areas of the site or imported to the site can be used to line the sand fitter. The fill soils should be compacted to 95% of the modified Proctor maximum dry density (ASTM D•1557). The fill soils should be compacted at a moisture content of -1 to 3 percent of the optimum moisture content. The fill soils should be compacted with a sheepsfoot type compactor in loose lifts not exceeding 8 inches. Grade controls should also be! maintained throughout the filling operations. All filling operations should be observed on a full-time basis by a qualified personnel to determine that the required degrees of compaction are being achieved. We recommend that a minimum of one compaction test per 2,000-square-foot area be performed for each lift of controlled fill. The elevation and location of the: tests should be clearly identified at the time of fill placement. Areas which fail to achieve the required degree of compaction should be re -worked until the specified degree of compaction Is achieved. Failing test areas may require moisture adjustments or other suitable remedial activities in order to achieve the required compaction. Report of Subsurface Exploration and Geotechnical Report — Addendum P683 MV22 Maintenance Hangar MCAS New River, North Carolina ECS Project 22.17368 We appreciate the opportunity to be of service to you during the design phase of this project and look forward to our continued involvement during the construction phase. If you have any questions concerning the information and recommendations presented in this report, please contact us at (910) 686-9114 for further assistance. Respectfully submitted, ECS CAROLINAS, LLP�CA!a,l��� Winslow E. Goins, P.E.: Project Engineer %�i.' North Carolina License ff,6." APPENDIX A -FIGURES '�E II II011— \` ;Ste�phenL. Neas, P.E �. . Principal Engineer North Carolina License No. 016085 APPENDIX B-DIRECT PUSH BORINGS APPENDIX C-LABORATORY TEST RESULTS APPENDIX D-PERMEABILITY ESTIMATIONS FROM CPT SOUNDINGS P-1, P-4, P-6, R-7 AND R-22 APPENDIX E-GENERAL CONDITIONS APPENDIX F-PROCEDURES REGARDING FIELD LOGS, LABORATORY DATA SHEETS, AND SAMPLES 0 iii AT �nM 11, All t J S61 P 4 Zr in E:PLORATIO-1. 2683 "VT2 LOCATIO." DIAGRAmin -,k:63^ I MCAS New River, NC Direct Push Borings P683 MV22 Maintenance Hangar MCAS New River, Onslow, County, North Carolina ECS Project No. 22.17368 2-15-2012 Location Depth Soil Descriotion B-1 0-12" Dark Brown silty SAND (fill) 12" 24" Tan fine SAND w silt 24"-60" Tan/orange/gray CLAY w sand 60-1-44" Tan Fine SAND Seasonal High Water Table was estimated to be at 18 inches below the existing grade elevation. Groundwater was not encountered up to 144 inches below the existing grade elevation. Location DeOh B-2 0-6" 6"-36" 36"-84" 84-144" Soil Description Dark Brown silty SAND (fill) Tan fine SAND w silt Tan/orange/gray CLAY w sand Tan fine SAND Seasonal High Water Table was estimated to be at 36 inches below the existing grade elevation. Groundwater was not encountered up to 144 inches below the existing grade elevation. Location Depth B-3 0-14" 14"-32" 32"-70" 70-144" Soil Description Dark Brown silty SAND (fill) Tan fine SAND w silt Tan/orange/gray CLAY w sand Tan fine SAND Seasonal High Water Table was estimated to be at 36 inches below the existing grade elevation. Groundwater was not: encountered up to 144 inches below the existing grade elevation. PER6IEABIL.ITY TEST REPORT TEST DATA: SAMPLE DATA: Specimen Height (cm): 15.37 Sample Identification: 3-21-12 ST-1 Specimen Diameter (am): 7.28 Dry Unit Weight (pcf): 94.9 Moisture Before Test (%): 26.7 Moisture After Test (R): 31.7 Run Number: 1 e Cell Pressure (psi): 83.0 Sat. Pressure (psi): 80.0 Diff. Head (psi): 5.2 Perin` (cm/sec): 1.24>: 10--7 u u U v 'a W M D J i O J LL 0 2 4 6 8 10 1 x 10^-9 H x 10^-7 B x 10--7 4 x 10^-7 2 x 10^-7 I x 10^-7 20 Visual Description: Orangish Brown and Gray, Clay Remarks: Sampled in situ via ' 2 • shelby tube Maximum Dry Density (pef): Optimum Moisture Content (2): Percent Compaction: Permeameter type: Flexible Wall Sample type: Shelby Tube TIME - t (sec) O 5000 10000 15000 20000 25 30 35 40 AVERAGE HYDRAULIC GRADIENT - dH/L (cm/cm) Project: P683 MV22 Maintenance Hanger Project No.: 17368 Location: Jacksonville, NC File No.: Date: 3/30/12 Lab No.: S-1a Tested by: KEL PERMEABILITY TEST REPORT Checked by: WEG — ECS Coro I i nos, LLP Test: FH - Fo I I i ng head C PERMEABILITY TEST REPORT TEST DATA: SAMPLE DATA: Specimen Height (cm): 15.23 Sample Identification: 3-21-12 ST-2 Specimen Diameter (cm): 7.29 Dry Unit Weight (pcf): 106.4 Moisture Before Test (%): 15.8 Moisture After Test (%): 17.7 Run Number: . 1 • Cell Pressure (psi): 86.0 Sat. Pressure (psi): 83.0 Diff. Head (psi): --S.1 Perm. (cm/sec): 1.87 x 11--4 Sol Visual Description: Light Brown, Orange, Silty Sand Remarks: Sompled.in-situ via 2 • Shelby Tube Maximum Dry Density (pcf): Optimum Moisture Content (%): Percent Compaction: Permeameter type: Flexible Wall Sample type: Shelby Tube TIME - t (sec) 0 50 100 150 200 3 6 9 12 15 1 x 10--3 8 x 10--4 B x 10-4 4 x 10^-4 2 x 10--4 1 x 10--4 10 15 20 25 30 AVERAGE HYDRAULIC GRADIENT - dH/L (cm/cm) Project: P683 My-22 Maintenance Hanger Project No.: 17368 Location: Jacksonville, NC File No.: Date: 4/4/12 Lab No.: ST-2 Tested by: KEL PERMEABILITY TEST REPORT Checked by: WEG ECS Carolinas, LLP Test: FH - Fal I ing head C PERMEABILITY TEST REPORT TEST DATA: SAMPLE DATA: Specimen Height (cm): 15.23 Specimen Diameter (cm): 7.29 Dry Unit Weight (pcf): 107.4 Moisture Before Test (%): 10.3 Moisture After Test (%): 0.0 Run Number: 1 • Cell Pressure (psi): 81.0 Sample Identification: 3-21-12 ST-3 Visual Description: Yellowish Brown, Gray, Silty Sand Remarks: Sampled in -situ via 2 • Shelby Tube 81.0 Maximum Dry Density (pcf): Optimum Moisture Content (%): Sat. Pressure (psi): 78.0 78.0 Diff. Head (psi): 3.2 3.1 Percent Compaction: Permeameter type: Flexible Wall Perm. (cm/sec): 1.62x10--4 1.05x10^-4 Sample type: Shelby Tube 0 0 a W D 7 J > 3 0 J lL n u N N E U Y I F H J H m W W W W a TIME - t (sec) 0 25 50 75 100 0 2 4 6 B 10 i x 10^-3 8 x 10^-4 8 x 10--4 4 x 10^-4 2 x 10--4 1 x 10--4 10 15 20 25 30 AVERAGE HYDRAULIC GRADIENT - dH/L (cm/cm) Project: P683 MV-22 Maintenance Hanger Project No.: 17368 Location: Jacksonville, NC: File No.: Date: 4/6/12 Lab No.: ST-3 PERMEABILITY TEST REPORT Tested Checked by: KEL by: WEG ECS Caro 1nos, LLP Test: FH - FalIing head C p6 Mnp P-1 B.Mtlp PJ N Y61NL fYlmYlo� gtlddm bmatl-�� ary6!(N Ye (1Y3 41ha STn 56t(NI) G9N (N p[(1tlf h(W( Sm ea%(N61 O] IlI MMS 5 =m 03 9.7 a0365 6 .mM a56 all a0o 5 ZMM am 114 O00 5 %Um a55 21A aM 6 •Nm am I10i a019S 5 IMM an 006 0=1 5 1bFO5 an M4 am 0 O.n M =7 alE] 6 ].ftm am 1561 Aa 3 amm LI6 Mm QV0 6 Inm M 151) a10 5 Mm U3 HIS 64♦ 6 _YtM LM an a1101 5 1aem LM 6a3S aYA 6 L22M LM a" am 5 1. 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This report does, not reflect specific variations that may occur between test locations. The borings were located where site conditions permitted and where it is believed representative conditions occur, but the full nature and extent of variations between borings and of subsurface conditions not encountered by any boring may not become evident until the course of construction. If variations become evident at any time before or during the course of construction, it will be necessary to make a re-evaluation of the conclusions and recommendations of this report and further exploration, observation, and/or testing .may be required. This report has been prepared in accordance with generally accepted soil and foundation engineering practices and makes no other warranties, either expressed or implied, as to the professional advice under the terms of our agreement and included in this report. The recommendations contained herein are made with the understanding that the contract documents between the owner and foundation or earthwork contractor or between the owner and the general contractor and the foundation, excavating and earthwork subcontractors, if any, shall require that the contractor certify that all work in connection with foundations, piles, caissons, compacted fills and other elements of the foundation or other support components are in place at the locations, with proper dimensions and plumb, as shown on the plans and specifications for the project. Further, it is understood the contract documents will specify that the contractor will, upon becoming aware of apparent or latent subsurface conditions differing from those disclosed by the original soil exploration work, promptly notify the owner, both verbally to permit immediate verification of the change, and in writing, as to the nature and extent of the differing conditions and that no claim by the contractor for any conditions differing from those anticipated In the plans and specifications and disclosed by the soil studies will be allowed under the contract unless the contractor has so noted the owner both verbally and in writing, as required above, of such changed conditions. The owner will, in turn, promptly notify this firm of the existence of such unanticipated conditions and will authorize such further exploration as may be required to properly evaluate these conditions. Further, it is understood that any specific recommendations made in this report as to on -site construction review by this firm will be authorized and funds and facilities for such review will be provided at the times recommended if we are to be held responsible for the design recommendations. APPENDIX F PROCEDURES REGARDING FIELD LOGS, LABORATORY DATA SHEETS AND SAMPLES Procedures Renardintt Field Loas, Laboratory Data Sheets and Samples In the process of obtaining and testing samples and preparing this report, procedures are followed that represent reasonable and accepted practice in the field of soil and foundation engineering. Specifically, field logs are prepared during performance of the drilling and sampling operations which are intended to portray essentially field occurrences, sampling locations, and other information. Samples obtained in the field are frequently subjected to additional testing and reclassification in the laboratory by more experienced soil engineers, and differences between the field logs and the final logs exist. The engineer preparing the report reviews the field and laboratory logs, classifications and test data, and his judgment in interpreting this data, may make further changes. Samples are taken in the field, some of which are later subjected to laboratory tests, are retained in our laboratory for sixty (60) days and are then discarded unless special disposition is requested by our client. Samples retained over a long period of time, even if sealed in jars, are subject to moisture loss which changes the apparent strength of cohesive soil generally increasing the strength from what was originally encountered in the field. Since they are then no longer representative of the moisture conditions initially encountered, an inspection of these samples should recognize this factor. It is common practice in the soil and foundation engineering profession that field logs and laboratory data sheets not be included in engineering reports because they do not represent the engineer's final opinions as to appropriate descriptions for conditions encountered in the exploration and testing work. On the other hand, we are aware that perhaps certain contractors submitting bids or proposals on work may have an interest in studying these documents before submitting a bid or proposal. For this reason, the field logs will be retained in our office for inspection by all contractors submitting a bid or proposal. We would welcome the opportunity to explain any changes that have been and typically are made in the preparation of our final reports, to the contractor or subcontractors, before the firm submits the bid or proposal, and to describe how the information was obtained to the extent the contractor or subcontractor wishes. Results of the laboratory tests are generally shown on the boring logs or described in the extent of the report, as appropriate. The descriptive terms and symbols used on the logs are described on the attached sheet, entitled General Notes. Lewis,Linda From: Lewis, Li nda Sent: Thursday, March 15, 2012 11:04 AM To: 'Luman, Travis M.' Subject: SW8 091113 P688 Apron Expansion Travis - I've gone through the application, calculations, narrative and plans for this project and am unable to find anything related to an allocation of BUA for future development of the Hangar. The plans only indicate the space where future construction will occur, but the application does not specifically allocate any BUA amount for that future construction. I can only surmise that no allocation has been made. You would have to recalculate the apron BUA and show that between the apron and the half of the hangar building that will drain to the infiltration basin, the total BUA already in the permit has not been exceeded. Then, you would break it down into its components, i.e., what's allocate for building and what's allocated for parking. Linda Lewis NC Division of Water Quality 127 Cardinal Drive Ext. Wilmington, NC 28405 910-796-7215 E-mail correspondence to and from this address may be subject to the North Carolina Public Records Low and may be disclosed to third parties. fti1tM If R.D. 10M ODAC11 Mob. To fir( SW8 o91113 C> , . �.D. PERINi7 -- bouNDA IfM %% 61 13 1 440 i 1 � I 9W mill -I T.7-+Z1 ---- - i� 1 i n! ---- - _-- -- _ -- MVI Li 11-- Poi GAAA� o � �.��YI •` 4 t1 D. 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EXISTING I-B HIGH DENSITY DRAINAGE BASIN, SF-4 • NEW RIVER INFILTRATION BASIN WETUNDS (TYP.) FOR OFFICIAL USE ONLY