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HomeMy WebLinkAboutSW8040323_HISTORICAL FILE_20050401STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW8 nLAQ323 DOC TYPE ❑ CURRENT PERMIT ❑ APPROVED PLANS HISTORICAL FILE ❑ COMPLIANCE EVALUATION INSPECTION DOC DATE 2ooSC)L4 YYYYMMDD �QF WATF9O Michael F. Easley, Governor �O G William G. Ross, Jr., Secretary �? r- North Carolina Department of Environment and Natural Resources > =i O Alan W. Klimek, P.E. Director Division of Water Quality April 1, 2005 Mr. Jon Vincent, Member/Manager Tri-Coast Properties, LLC 1508 Military Cutoff Road, Suite 302 Wilmington, NC 28403 Subject: Approved Plan Revision Shallotte Shops Stormwater Project No. SW8 040323 Brunswick County Dear Mr. Vincent: On February 7, 2005, the Wilmington Regional Office received a plan revision for Stormwater Management Permit Number SW8 040323. The revisions include the deletion of a building unit and parking area, and the addition of a drive -through lane. The net change in total built - upon area is zero, however the amount of built -upon area available for future development is reduced to 7,499 square feet. 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 plans for your files. Please replace the old approved plan sheets C1 and C2 with the new ones, enclosed. This plan revision supercedes the one issued on October 14, 2004. Please be aware that all terms and conditions of the permit issued on April 12, 2004, 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 approved through this Office 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 concerning this matter, please do not hesitate to call me at (910) 395-3900. Sincerely, Linda Lewis Environmental Engineer ENB\arl: S:\WQS\STORMWAT\REVISION\040323.apr05 cc: Phil Tripp, P.E., Tripp Engineering Delaney Aycock, Brunswick County Building Inspections Linda Lewis Wilmington Regional Office Central Files North Carolina Division of Water Quality 127 Cardinal Drive Extension Phone (910) 395-3900 Customer Servicel-871{23-6748 Wilmington Regional Office Wilmington, NC 28405-3845 FAX (919)733-2496 Internet. h2o.ennstate.nc.us One NorthCarolina An Equal Opportunity/Affirmative Action Employer— 50%Recycledll0°/ Post Consumer Paper Naturally ItFEB 15,2005 02:25P February 15, 2005 9107635631 TRIPP EriliiGiNE*ERIN­6� P.C. 419 Chescmk!st�e6i;- wilrtlingron, North C4r:6Iin*! -28401 1111011c: (910) 763-5100 - liAX (910) 763-5631 NCDENR Division Water Quality 127 Cardinal Drive Wilmington, NC 28405-3845 Attn-. Ms.,Lizidal Lewis it Re: Shallotti!Shops Project No. SWS 040323 TIE 03128 Dear Linda; Per your'remarks via facsimile dated February. 11. 2005, we offer the following: We have added an asphalt access area for a drive-ilrru to accommodate a tenant for the proposeil ng. buildiThis accommodation resulted -in-a reduction to the building . ;. �ml t '11-i - A impervious area (eight 22' x 57,' units in lieu of�nifiu 22,,l.x 57' units) and future impervious area in order to maintain the'pfevi'c)usly+perhiitte',d'impervious area. Hence, the request for a plan revision. Sincerely, Tripp Engineering, P.C. 4k "U'r"t Monica V. Loughlin N4VL:dcb Enc. page State of North Carolina Department of Environment and Natural Resources r Wilmington Regional Office Michael F. Easley, Governor William G. Ross Jr., Secretary FAX COVER SHEET Sh2(tofIe SiV195 SW 504-0323 Date: 2 -11-05 No. Of Pages: 2 To: Hvnl'c2 LcughUn From: Und2 LeyjlS CO: CO: OW!Q FAX #: '703-5Co31 FAX#: 910-350-2004 REMARKS: Re25e P)-0�(I-Je 2rq eX(A 2n 2 h-CY) of wh2i- fhe; (art-oosPd revisicr)s en e 127 Cardinal Drive Extension, Wilmington, N.C. 28405-3845 Telephone (910) 395-3900 Fax (910) 350-2004 An Equal Opportunity Affirmative Action Employer FILE MODE 926 MEMORY TX P. 1 * * COMMUNICATION RESULT REPORT`(:FEB.'11.2005 12:OSPM ) TTI NCDENR WIRO OPTION ADDRESS (GP.OUP,lr6:: RESULT PAGE -------------------------------------- 97635631 f ' OK P. 2/2 C � i�Jy 1, u.l• 4 , a r I♦ � a '- 1�^i IinJ'i �rlL 4xj i vJ � ',i•' * gib.. � . I REASON FOR ERROR E-1) HANG UP OR LINE FAIL E-3) NO ANSWER State o Department of Envir( Wilmingti Michael F. Easley, Governor I F FAX C( I Date: 2- II_OS N To: �ianlca �vahlir3 F CO: C F. REMARKS: f�IQ2se rr��'de c.0 2+- -Fh e p�0os 127 Cardinal Drive Extension, Wilmington, N.C.: An Equal Opportunity E-2) BUSY E-4) NO FACSIMILE CONNECTION Resources William G. Ross Jr., Secretary SHEET SwJ8G4v323 2 of ne (910) 395,3900 Fox (910) 350.2001 Employer TRIPP ENGINEERING, P.C. 419 Chestnut Street Wilmington, North Carolina 28401 Phone: (910) 763-5100 • FAX: (910) 763-5631 February 4, 2005 NCDENR Division Water Quality 127 Cardinal Drive Wilmington, NC 28405-3845 Attn: Ms. Linda Lewis Re: Shallotte Shops Project No. SW8 040323 TE 03128 Dear Linda: Thank you for clarifying the difference between a permit modification and a plan revision. With that, I am requesting a plan revision for the above referenced project. Enclosed please find two (2) sets of revised plans and calculations for your approval. Please contact us with any questions, comments or if you need additional assistance. Thank you. Sincerely, Tripp Engineering, P.C. Ak, /V- ' /J' Monica V. Loughlin MVL:dcb Enc. FES 0 7 2005 2/4/2005 Shallotte Shops 03128 MVL Stormwater Calculations Total Draina a Area s . ft. acres 88,652 2.04 Impervious Area Land Use s .ft, acres buildin s 10,032 0.23 as halt 43,480 1.00 concrete 3,016 0.07 future 7,499 0.17 Tota I 64,027 1.47 Stormwater Calculations: Time of Concentration Hydraulic Length (L) = 630 ft. hange in Height (H) = 4 ft. Tc = (La /H).Joo / 128 = 7.84 min. Flow for 10 year, 6 hour Storm (Q10) QPRE _ (CPRE) x (hc) x (Area) 3.21 cfs QPosT = (CPosT) x (I,c) x (Area) = 9.74 cfs Detention Pond Design: D-a Q;- Surface Area (sq. ft.) 4,668 jNormal g531.00 5,725 8,837 320 Total Provided Storage Volume: Vol. _ [(Normal pool SA + Flood Pool SA) / 2] x (F.P. elev. - N.P. elev.) = 5,716 cu.ft. % impervious = 0.722 = 72.2% say 73.0% CPRE - 025 CPosT = (% imp.)(.95)+(1% imp-)(.25) 0.76 Ito = 6,30 in/hr 150 = 7.79 in/hr Flow for 50 year, 6 hour Storm (Cleo) QPRE _ (CPRE) x (I10) x (Area) 3.96 cfs QPosT = (CPosT) x (ho) x (Area) = 12.05 cfs State Surface Area Requirement at normal pool Pond side slopes = 3 :1 Depth below N.P. = 5 ft. SA/DA = 0.0521 (Chart for 90% TSS Removal for Wet Detention Pond without Vegetative Filter) Required SA = (SA/DA) x (Total Drainage Area) = 4,619sq. ft, State Volume Requirement for Store e of first 1" runoff: Rv = .05+.009(Percent Impervious) 0,7000056 in/in Vol. = (Design Rainfall)(Rv)(Drainage Area) 71 cu. ft. =O QOFESSIpy��.l, y 9r9, SEAL S -0 17374 �y �OREGOR;,�t 03128-Pond 1 of 2 �Y �' r i. w.f<.:_ .t" v� 6�� �C.�,. `\ S'F `y' .Nf 2/4/2005 MVL Pond Volume: Shallotte Shops Stormwater Calculations Bottom SA = 320 sq. tt. Normal Pool SA = 4,668 sq. ft. Vol. _ [(N.P. SA + Bottom SA) / 21 x (N.P. el. - Bottom el.) 12,470 cu.ft. ForebaV: Required Volume Vol. = 20% of storage volume 2,494 cu.ft. Provided Volume Bottom SA = 356 sq. ft. Normal Pool SA = 1,395 sq. ft. Vol. _ [(N.P. SA + Bottom SA) / 21 x (N.P. el. - Bottom el.) = 9 R97 ... ft 3 ft. Outlet Structure Design: Flow for 2-day drawdown. for 1st 1" of stormwater, Q = Required Vol. / 172,800 sec. (2-days) = 0.030 cfs r Area or ripe for t-uay oidwuuwn. = Q/ [Cd x SQRT(2 x g x h)] Cd = 0.6 g = 32.2 ft./sz h = (F P, elev.-N.P elev.)/2 0.55 ft. A = 0.0084 sq. ft. Diameter of Pipe for 2-daV drawdown DIA. = SQRT[(A x 4) / pi] = 0.1033 1 = 1.24 Use 1.0" orifice Outlet Structure Check: Using a 4' x 4' Basin, Perimeter (L) = 16 ft. Q = CIA C = (% imp.)(.95) + (1-% imp.)(.25) = 0.76 1 = 6.30 in. for a 10 yr. Storm A = 2.04 Acres = 9.74 cfs Flow for 5-day drawdown: for 1st 1" of stormwater, Q = Required Vol. /432,000 sec.(5-days) 0.012 cfs Nequirea Area or ripe Tor z)-oay ❑rawoown. A= Q/ (Cd x SQRT(2 x g x h)] Cd = 0.6 g = 32.2 ft./s2 h= IF.P. elev.-N.P. elev.)/2 = 0.55 ft. A= 0.0034 sq. ft. Diameter of Pipe for 5-day drawdown: DIA. = SQRT[(A x 4) / pi] 0.0653 ft. 0.78 in. Q= CwxLxH" H = [Q / (Cw x L)]v' Cw = 3 0.35 ft. Peak elevation = flood pool elevation + H 32,45 ft. 03128 03128-Pond 2 of 2 Shallotte Shops Revision Subject: Shallotte Shops Revision From: Linda Lewis <Linda.Lewis@ncmail.net> Date: Wed, 26 Jan 2005 12:27:13 -0500 To: Monica Loughlin <trippeng@ecJT.com> Monica: First, you need to understand the difference between a permit modification and plan revision. The permit modification involves the rewriting of the permit to charfge something and requires a $420.00 fee. A plan revision involves the rearrangement of the same amount of built -upon area, and requires no fee. You appear to be proposing both, but you have not submitted the required fee. Second, I see from the revised supplement that the permanent pool and storage elevations have changed from what was permitted. If this is the case, then the permit will have to be rewritten to reflect these changes, meaning a $420.00 fee is required. The revised plans we approved on October 14, 2004, and the permit issued on April 12, 2004, indicate a permanent pool (normal pool) elevation of 31.0 and a temporary pool (flood pool) elevation of 32.1, while the plans submitted on January 21 indicate 30.8 and 31.9, respectively. While the difference remains the same, the elevations on the plans are different than what is shown in the permit. If you change your pond details and go back to the permitted elevations, then I can treat this as a plan revision, with no fee. Please advise as to what course of action you wish to take. Linda 1 of 1 1/26/2005 12:27 PM North Carolina James D. Simons, PG, PE Director and State Geologist r NC®ENR Department of Environment and Division of Land Resources Land Quality Section January 25, 2005 RECEIVE4 D IAN 66 2005 BY:__ Natural Resources Michael F. Easley, Governor William G. Ross Jr., Secretary LETTER OF RECEIPT OF REVISED EROSION CONTROL PLAN Tri Coast Properties Mr. Jon T. Vincent, Mbr/Mgr. 1508 Military Cutoff Road Wilmington, NC 28403 RE: Project Name: Shallotte Shops Project ID: Bruns-2004-269 County: Brunswick River Basin: Cape Fear Submitted By: Tripp Engineering Date Received by LQS: January 21, 2005 Plan Type: REVISED Dear Mr. Vincent: This office has received the revised soil erosion and sediment control plan submitted for the project listed above. G.S. 113A-54.1(a) requires that this office approve or disapprove a submitted revised plan within 15 days of receipt of such plan. Failure to act by this office within this time period shall be deemed approval of the revised plan. Commencement or continuation of a land -disturbing activity under the jurisdiction of this Act prior to the approval of an erosion and sediment control plan is a violation of the Act. The approval of an erosion and sediment control plan is conditioned on the applicant's compliance with Federal and State water quality laws, regulations and rules. If you have questions please do not hesitate to contact this office. Your cooperation in this matter is appreciated and we look forward to working with you on this project. Sincerely, Todd C. Walton Land Quality Section cc: Monica V. Loughlin, Tripp Engineering, PC LQS—WiRO; SWS-WiRO W ilntington Regional Office 127 Cardinal Drive Extension, Wilmington, NC 28450 Phone: 910-395-3900 Fax: 910-350-2004 TRIPP ENGINEERING, P.C. 419 Chestnut Street Wilmington, North Carolina 28401 Phone: (910) 763-5100 • FAX: (910) 763-5631 January 14, 2005 NCDENR Division Water Quality 127 Cardinal Drive Wilmington, NC 28405-3845 Attn: Ms. Linda Lewis Re: Shallotte Shops Project No. SW8 040323 TE 03128 Dear Linda: I'm writing to request a modification to existing permit No. SW8 04023. Due to a contract tenant that requires a drive-thru, the building, parking and access areas have been reconfigured accordingly. Please note that the drainage area and impervious surfaces have not changed. Revised drawings, calculations, narrative, page 2 of the stormwater permit application, and page 1 of the wet detention basin supplement are attached. Please review for approval and contact us with any questions, comments or if you need additional assistance. Thank you. Sincerely, Tripp Engineering, P . AAM-(, v ° t, V� Monica V. Loughlin MVL:dcb JAN 2 1 '1005 Enc. 1/10/2005 MVL Shallotte Shops Stormwater Calculations 03128 Total Drainage Area s . ft. acres 88,652 2.04 Impervious Area Land Use sq. ft. acres buildings 10,032 0.23 asphalt 43,480 1.00 1 concrete 3,016 0.07 future 7,499 0.17 Total 64,027 1.47 Stormwater Calculations: Time of Concentration Hydraulic Length (L) = 630 ft. hange in Height (H) = 4 ft. Tc = (L' /H).'6° / 128 = 7.84 min. Flow for 10 year, 6 hour Storm (Q,o) OPRE _ (CPRE) x (hc) x (Area) = 3.21 cfs o PosT = (CPosT) x (ho) x (Area) 9.74 cfs Detention Pond Design: Pond Size: Elevation ft. Surface Area (sq. ft.) Normal Pool - 30.80 4,668 Flood Pool 31.90 5,725 Top of Bank 34.80 8,837 Bottom of Pool 25.80 320 Total Provided Storage Volume: Vol. _ [(Normal pool SA + Flood Pool SA) / 2] x (F.P. elev. - N.P. elev.) = 5,716 cu.ft. % impervious = 0.722 0 say 73.0% CPRE = 0.25 CPosT= (%imp.)(.95)+(1%imp.)(.25) = 0,76 Ito = 6.30 in/hr Iao = 7.79 in/hr Flow for 50 year, 6 hour Storm (Qso) QPRE _ (CPRE) x (110) x (Area) = 3.96 cfs QPosT = (CPcsT) x (1io) x (Area) = 12.05 cfs State Surface Area Reauirement at normal cool Pond side slopes = 3 :1 Depth below N.P. = 5 ft. SA/DA = 0.0521 (Chart for 90% TSS Removal for Wet Detention Pond without Vegetative Filter) Required SA = (SA/DA) x (Total Drainage Area) 4,619sq. ft. State Volume ��jj CARP RECEIVED \\�°pFFsS%pyL9 �ZFa SEAL 4; 17374 FEB 0 7 2005 ti`•.F Q: `Q DweGciNEy�Q/ SNBU40323 �� REGG PROJ # /��7�//llfllltltttl" irement for Storaqe of first 1" 03128-Pond 1 of 2 •1 /10/2005 MVL Shallotte Shops Stormwater Calculations 03128 Pond Volume: Bottom SA = 320 sq. ft. Normal Pool SA = 4,668 sq. ft. Vol. _ [(N.P. SA + Bottom SA) / 21 x (N.P. el. - Bottom el.) = 12,470 cu. ft. I Forebay: Required Volume Vol. = 20% of storage volume = 2,494 cu. ft. Bottom SA = 356 sq. ft. Normal Pool SA = 1,395 sq, ft. Vol. _ [(N.P. SA + Bottom SA) / 21 x (N.P. el. 2,627 cu,ft. depth = 3 ft. Outlet Structure Design: Flow for 2-day drawdown: for 1st 1" of stormwater, Q = Required Vol. / 172,800 sec. (2-days) = 0.030 cfs rea Area or ripe for o-aay arawaown: A= Q/ [Cd x SQRT(2 x g x h)] Cd = 0.6 9 = 32.2 ft./s2 In = (F.P. elev.-N.P elev.) /2 = 0.55 ft. Diameter of Pioe for 2-dav drawdown DIA. = SQRT[(A x 4) / pi] 0.1033 ft. 1.24 Use 1.0" orifice Outlet Structure Check: Using a 4' x 4' Basin, Perimeter (L) = 16 ft. Q = CIA C = (% imp.)(.95) + (1% imp.)(.25) = 0.76 1 = 6.30 in. for a 10 yr. Storm A = 2.04 Acres = 9.74 cfs Bottom el.) Flow for 5-day drawdown: for 1st 1" of stormwater, Q = Required Vol. /432,000 sec.(5-days) 0.012 cfs Kea Wrea Area or F me Tor o-oav arawaown LA = Q/ [Cd x SQRT(2 x g x h)] Cd = 0.6 9 = 32.2 ft./sz h = (F.P. elev. - N.P. elev.) / 2 = 0.55 ft. =_ 0.0034 sq. ft. Diameter of Pipe for 5-day drawdown: DIA. = SQRT[(A x 4) / pi] = 0.0653 ft. 0.78 in. Q= CwxLxH H = [Q / (Cw x L)IM Cw = 3 0.35 ft. Peak elevation = flood pool elevation + H 32.25 ft. 03128-Pond 2of2 O1/14/05 Stormwater Narrative Shallotte Shops Brunswick County, NC TE03128 Shallotte Shops is a 2.04-acre existing vacant tract proposed for a commercial shopping center. Impervious areas include 10,032 sf of building, 3,016 sf of sidewalk and 43,480 sf of asphalt. 7,499 sf is allocated for future impervious area, creating a total lot impervious area of 64,027 sf. The total percent impervious is 72.2%. The project will be treated by wet detention. The detention pond will be designed to meet the State's V and the County's 10-year pre -post requirement. Outflow from the pond drains to the Shallotte River, classification SC HQW.