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HomeMy WebLinkAboutSW6120704_HISTORICAL FILE_20120905STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW zzz� DOC TYPE ❑ CURRENT PERMIT ❑ APPROVED PLANS HISTORICAL FILE DOC DATE A6&� YYYYMMDD NC®ENR North Carolina Department of Environment and Beverly Eaves Perdue Governor Mr. Charles J. Harrell Harrell's Service Center 1122 Gillespie Street Fayetteville, NC 28306 Division of Water Quality Charles Wakild, P.E. Director August 9, 2012 Subject: Approved Plan Revision Stormwater Permit No. SW6120704 Harrell's Service Center Harnett County Dear Mr. Harrell: ®ENR—FRO; ") SEP o 5 2012 Natural ResourceowQ Dee Freeman Secretary The Stormwater Permitting Unit received a request for a plan revision for Stormwater Management Permit Number SW6120704 on August 3, 2012. The plan revision includes revisions to add a pretreatment collar to the swale receiving flow from the gravel area; and does not change the total allowable amount of BUA on the site. It has been determined that a formal permit modification is not required for the proposed changes. We are forwarding you an approved copy of the revised plan for your files. Please be aware that all terms and conditions of the permit issued on August 3, 2012 remain in full force and effect. Please also understand that the approval of this revision to the approved plans for the subject State Stormwater Permit is done on a case -by -case basis. Any other changes to this project must be submitted to and approved through the Division of Water Quality prior to construction. The issuance of this plan revision does not preclude the permittee from complying with all other applicable statutes, rules, regulations or ordinances which may have jurisdiction over the proposed activity, and obtaining a permit or approval prior to construction. If you have any questions, or need additional information concerning this matter, please contact Robert Patterson at (919) 807-6375; or robert.patterson@ncdenr.gov. Sincerely,�7vP,,,/,7k for Charles Wakild, P.E. enclosures - approved revised plan cc: SW6120704 File w/ enclosure ec: George M. Rose, PE John Lennon -- Lennon Family Limited Partnership Mike Lawyer - Fayetteville Regional Office Wetlands and Stormwater Branch 1617 Mail Service Center, Raleigh, North Carolina 27699.1617 Location: 512 N. Salisbury St. Raleigh, North Carolina 27604 Phone: 919-807-63001 FAX: 919-807-6494 Internet: www.ncwaterquality.org An Equal Opportunity 1 Affirmative Action Employer One NonhCarolina Aaturally GEORGE M. ROSE, P.E. KET7 Q Q)F VR° MMOTTId P.O. Box 53441 Fayetteville, NC 28305 (910) 485-5822 Fax (910) 485-5823 pa4�?-- TO Vla DATE LZ— .�+ JOB NO. ATTE,fnON RE WE ARE SENDING YOU W-'AiTACHED ❑ UNDER SEPARATE COVER COPIES DATE NO. DESCRIPTION THESE ARE TRANSMITTED as checked below: FOR APPROVAL ❑ APPROVED AS SUBMITTED ❑ FOR YOUR USE ❑ APPROVED AS NOTED ❑ AS REOUESTED ❑ RETURNED FOR CORRECTIONS ❑ FOR REVIEW AND COMMENT CI REMARKS COPY TO SIGNED:• e M• - ,.i . . 7 s GEORGE M. ROSE, P.E. P.O. Box 53441 Fayetteville, NC 28305 (910) 485-5822 Fax (910) 485-5823 oeltv— To W tVL 2-1404141- V64-1 WE ARE SENDING YOU ATTACHED LETTER OF TRANSMITTAL DATE 'I - 9j � , ( *2-- 1 JOB NO. ATTENTION fl ��rA ❑ UNDER SEPARATE COVER _-■ w r f THESE ARE TRANSMITTED as checked below: Ve'FOR APPROVAL ❑ APPROVED AS SUBMITTED ❑ FOR YOUR USE ❑ APPROVED AS NOTED ❑ AS REQUESTED ❑ RETURNED FOR CORRECTIONS ❑ FOR REVIEW AND COMMENT ID REMARKS COPY TO SIGNED: " � �• a AEW NCDENR North Carolina Department of Environment and Natural Resources Division of Water Quality Beverly Eaves Perdue. Charias Wakild, P,E. Governor Director July 26, 2012 Mr. George M. Rose, PE P.O. Box 53441 Fayetteville, NC 28305 Subject: Request for Additional Information Stormwater Project No. SW61120704 Harrell's Service Center Harnett County Dear Mr. Rose: Dpe Frepman oecretaf y The Division of Water Quality Central Office received a Stormwater Management Permit Application for the subject project on July 20, 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: 1. Please delineate any wetlands in and around the project; or provide a note on the plans that none exist. 2. Please delineate the drainage area (DA) of the infiltration basin (including the basin itself) on the plans. 3. The DA must be based on the actual delineated DA of the infiltration basin, not the property area, as shown. This must include any offsite area not bypassed around the infiltration basin. Based on the grading, it appears there is some offsite area from the north draining to the infiltration basin. This total area must be accounted for in the sizing of the basin. Please revise all forms, calculations, and plans as needed. 4. The construction sequence needs to be revised to address cleanout of, and the conversion to the permanent infiltration basin. S. There is an error in the Simple Method calculation for the minimum required treatment volume. 38.4% BUA was used instead of 58.13%. That said, since the basin is being designed to infiltrate the 10-yr storm, it will not affect the basin size, only the value reported on the supplement form and calculations. _ -states-that sod mitt-be_used-around-the4nfiltration.basin,-but:that-is-not-reftected_on- --_ the plans. 7. The TC el. at the northern most corner of the parking lot appears to be incorrect; lower than intended. Wetlands and Stormwater Branch 1617 Mail Service Center, Raleigh, North Carolina 27699-1617 One Location: 512 N. Salisbury St. Raleigh, North Carolina 27604 NorthCaroilina Phone: 919-807-63001 FAX: 919M7-6494 atuf+a ly Internet: WW4v.n[.vva!Prg1l?litlr org l/ L An Equal Opportunily 1 Affirmative Action Employer Mr. George M. Rose, PP SW6120704 - Harrell's Service Center July'26, 2012 8. It is strongly recommended to not have gravel areas when using an infiltration basin. The fines in the gravel will most likely lead to clogging and potentially failure of the infiltration basin. If gravel must be used, we recommend using a washed stone free of fines and rigorous pretreatment of that area before draining into the infiltration basin. Please provide a detail for the gravel/stone section. Please note that this request for additional information is in response to a preliminary review. The requested information should be received by this Office prior to August 26, 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 or fax your request for a time extension to the Division at the address and fax number at the bottom of this letter. The request must indicate the date by which you expect to submit the required information. The Division is allowed 90 days from the receipt of a completed application to issue the permit. The construction of any impervious surfaces, other than a construction entrance under an approved Sedimentation Erosion Control Plan, is a violation of NCGS 143-215.1 and is subject to enforcement action pursuant to NCGS 143-215.6A. All revised original signed documents must be returned or new originals must be provided. Copies are not acceptable. Any revised calculations or plans must be sealed, signed, and dated. Please reference the State assigned project number SW6120704 on all correspondence. If you have any questions concerning this matter please feel free to call me at (919) 807-6375, or at robert.patterson@ncdenr.gov. cc: SW6120704 File ec: Charles J. Harrell - Owner Mike Lawyer -- Fayetteville Regional Office Sincerely, Robert D. Patterson, PE Environmental Engineer Stormwater Permitting Unit Page 2 of 2 Application' Completeness Review i2l" First Submittal ❑ Re -submittal Date Received: Reviewed: L 8y Development/Project Name: _]44te + 44t s_ S/-y'1yicri- Ce/V74,f_ Receiving stream name t D 6-+e 3t4,e,,C_e classification: C� For post -construction requirements, a program will be deemed compliant for the areas where it is implementing any of the following programs: WS-I, WS-ii, WS-m, WS-IV, HQW, ORW, Neuse River Basin NSW, Tar -Pamlico River Basin NSW, and the Randleman Lake Water Supply Watershed Nutrient Management Strategy. High Density Projects that require a 401/404 within an NSW require 85% TSS, 30% TN and 30% TP removal. T&E Species (Goose Creek, Waxhaw Creek or Six Mil Creek Water Sheds) Latitude and Longitude: 3 i " 6 `I� °_Oy�_b�" Project Address: J 1jE.FA4o t_ -Xvz t2 **b , C ^1 4C�e� Engineer name and firm: _� Iu to (Las -e- a M Jurisdiction 5"" q-r vA ❑ Low Density (no curb and gutter) ❑ Low Density.with curb and gutter outlets b'H gh Density ❑ Other ❑ 401/404 impacts to surface waters, wetlands, and buffers (add language to cover letter and/or addinfo letter) Lr- Bt1A -5V o d Check for $505.00 included 9' Original signature (not photocopy) on application' 2f/' Legal signature (Corporation-VP/higher, Partnership -General Partner/higher, LLC-member/manager, Agent). Check spelling, capitalization, punctuation: htip:,/www.secretary.state.nc.us/corporations/thepage.aspx If an agent signs the application, a signed letter of authorization from the applicant must be provided which includes the name, title, mailing address and phone number of the person signing the letter. ❑ For subdivided projects, a signed and notarized deed restriction statement er"' Sealed, signed & dated calculations 2,'� Correct supplement and O&M provided for each BMP on site (check all that were provided & number of each) ❑ Bioretention Li Dry Detention Basin ❑ Filter Strip ❑ Grass Swale U' Infiltration Basin ❑ Infiltration Trench ❑ Level Spreader ❑ Permeable Pavement ❑ Restored Riparian Buffer ❑ Rooftop Runoff Management ❑ Sand Filter ❑ Stormwater Wetland ❑ Wet Detention Basin ❑ Low Density ❑ Curb Outlet ❑ Off -Site ❑ NCDOT Linear Road Two sets of sealed, signed & dated layout & finish grading plans with appropriate details e' Narrative Description of stormwater management provided m— Soils report provided r ❑ Wetlands delineated or a note on the plans that none exist on site and/or adjacent property Details for the roads, parking area, cul-de-sac radii, sidewalk widths, curb and gutter; r� Dimensions & slopes provided Drainage areas delineated ❑ Pervious and impervious reported for each ❑ Areas of high density Inspection and maintenance agreements provided o Application complete I9"Application Incomplete Returned: (Date) Comments t✓d--r1- qA/P S ,a/t7-Tr, -C> 9 February 9, 2009 Revision 4 4'J4' r n Jir �• s t.'.�5. y 5�•1r. .5 HARRELL'S SERVICE CENTER BUFFALO LAKE ROAD, HARNETT COUNTY STORMWATER CALCULATIONS Revised 7-30- l 2 Total area in tract = 74,235 sf = 1.70 acres Offsite area draining to this site = 0 acres Total drainage area = 1.70 acres Proposed impervious area = 43,155 sf= 0.99 acres Remaining impervious (grassed) area = 0.71 acres From Harnett County Soil Survey, entire site is Wtb sandy soils or Group A soils per Table 3-3 of the DENR BMP Manual. On -site soil tests show the infiltration rate of the soil in the area of the proposed basin is 16.05 inches per hour, allowing for the design of an infiltration basin to accommodate post -development flows. PART A — STORMWATER CALCULATIONS FOR SIZING THE BASIN Use SCS method to determine pre -development flows from 1.70 acres of grassed and weeded areas (current conditions). Pre -development curve number for Group A soils for open space, fair condition is 49 per Table 3-5. Determine runoff depth for 1-year and 10-year and 100-year storms (24-hour duration) using precipitation frequency data server at htt :Hlidsc.iiws.noaa. ,,ovlhdsc/ tds/orbhlc ptds.litml. -year (5 minute time of concentration) = 3.07 inches 10-year (5 min) — 5.44 inches 100-year (5 min) = 8.20 inches Determine post -development curve number. Impervious area consists of the footprint of the proposed building the proposed sidewalk and asphalt and gravel parking areas = 43,155 sf (58.1 % of the site). The remaining 31,080 sf (41.9%) of the site will remain fair condition open space. Post -development CN = (0.581)(98) + (0.419)(49) = 77.5 See routing report for results of routing the design storms. Check to see if the pond will hold 2 times the water quality volume in order to eliminate the need for treatment of flows bypassing the pond. Determine the volume required to capture the first I -inch of rainfall from the l0-year storm to be drawn down over 5 days (then double that). Using the Simple Method , Rv = 0.05 + 09 In 1n = 0.581 Rv = 0.05 + 0.9(.581) 0.57 4 Volume of runoff that must be controlled is: V = 3630(RD)(Rv)A where Ri)= l inch = 3630(l)(0.57)(1.70) = 3,517 cubic feet (3517)(2) = 7,034 cubic feet Storage available in the pond is 10,625 cubic feet or 3.0 times the water quality component — therefore no treatment required for any flows bypassing the pond. PART B — STORMWATER CALCULATIONS FOR SIZING PIPES Determine I for I -year, 10-year and 100-year storms using precipitation frequency data server at http://lidsc.nws.noaa. rov/hLisc/pfds/orb/nc pfds.html. 1-year (5 minute time of concentration) intensity = 3.07 inches per hour 10-year (5 min) = 5.44 inches per hour 100-year (5 min) = 8.20 inches per hour Size the pipe leaving CI-1 Q i o = CIA where C = 0.95 for paved areas and rooftops with area of 14,732 square feet = 0.95(5.44)(0.34) = 1.8 cfs Check capacity of 15" RCP at 0.75% slope using Manning's Equation. Q=1.49/nARz/3Suzwhere R = 1.23/3.92 = 0.31 = 1.49/0.013(1.23)(.31)2/3(0.075)1/2 = 17.6 cfs therefore 15" pipe is adequate Size the pipe leaving Cl-2 Qio= CIA where C = 0.95 for paved areas and rooftops with area of 13,032 square feet = 1.8 (from CI-1) + 0.95(5.44)(0.30) = 3.4 cfs Therefore 15" pipe at 1.00% is adequate Determine velocity at 15" F'ES outlet V = Q/A = 3.4/ 1.23 = 2.76 ft/sec Check rip rap energy dissapator size using Figure 8.06a of the North Carolina Erosion and Sediment Control Planning and Design Manual. By judgment use 6' x 6' rip rap, maximum stone diameter 6", apron thickness 12". PART C — EROSION CONTROL CALCULATIONS SEDIMENT TRAP SIZING CALCULATIONS Infiltration Basin (to be used as temporary sediment trap during construction) Disturbed area = 1.70 acres Storage required = 1.7(3600 cf/ac) = 6,120 cubic feet Infiltration basin is adequate since it's capacity is 10,625 cubic feet. Check surface area required = 435 sf X Qio where Qio= CIA Weighted C = 43155/74052(0.95) + 30897/74052(0.15) = 0.62 Qio= 0.62(5.44)(1.7) = 5.7 efs Surface area = 435(Qto) = 435(5.7) = 2,480 sf Surface area of infiltration area at elevation 346 is 4,877 sf -- therefore basin can adequately serve as temporary sediment trap. .•••���c�•CARO O• . GINE� OE M