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HomeMy WebLinkAboutSW6071002_HISTORICAL FILE_20080109STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. DOC TYPE ❑ CURRENT PERMIT ❑ APPROVED PLANS C HISTORICAL FILE j COMPLIANCE EVALUATION INSPECTION DOC DATE oGlfD YYYYMMDD Jordan - Tew & Associate's, P.A. l� ENGINEERING, SURVEYING, MATERIALS TESTING & PLANNING lc-) F 102 WealBroad Sheet (Zip 28334) �Poet OSX Bax 249fin, North Carollaa 2833S Ronma & Jordan, P.L.S. Johnny 01cm Taw, P.B. �CvwrwaTev LETTI+,R OF TRANSMITTAL ne✓.Ni-ti-i vnif) To: Date; 1 06 N C. j7'yiSi��l lt/ r v Company. Q j Locationy : i�uvn� efawo / All Ma,-1 llrvitf Gevt*r Project Name; Ac,Ie� nl,c. �7699- 16/7 ��tristiQH G�W�Q� �on++w4'itP P✓u}.gj-#SWbor7/Qc We Transmit : Herewith Ella Accordance With Your Request The Following: 13 Drawings ❑ Preliminary ❑ Test Results . WOther For Your: t.:1 Approval ❑ Use ❑ Review & comment [rl Record Remarks: Transmitted By; j Copies To: \JZ -`�� -..; -q -+ _: ,� ; �W y.� N.�] ,y 1�,� �: .. ��•� Michael F. Easley, Governor William G. Ross Jr., Secretary North Carolina Department of Environment and Natural Resources Coleen H. Sullins, Director Division of Water Quality December 10, 2007 Glenn Tew Jordon—Tew & Associates, P.A. P.O. Box 249 Dunn, North Carolina 28335 Subject: Request for Additional Information Stormwater Project No. SW6071002 Pleasant Union Christian Church Harnett County, North Carolina Dear Mr. Tew: The Division of Water Quality received a Stormwater Management Permit Application for the Pleasant Union Christian Church Expansion onon October 31, 2007. A preliminary review of that information has determined that the application is not complete. The Season High Water Table (SHWT) was not provided. Please provide the SHWT. The permanent pool elevation must be above the SHWT. Also, provide information that demonstrates that the soils will support a Wet Detention Pond Design. 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 January 15, 2008, 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. Please reference the State assigned project number, SW6071002, on all correspondence. If you have any questions concerning this matter please feel free to call me at (919) 733-5083 x 545. Sincerely, Mike/Randall Engineer, Stormwater Permitting Unit cc: Stormwater Permitting Unit file 0. N����nnCaro ina dvatura) 'North Carolina Division of Water Quality 1617 Mail Service Center Raleigh, NC 27699-1617 Phone (919) 733-5083 Customer Service Internet: % w v ncw.1tem ally o e Location: 512 N. Salisbury St. Raleigh, NC 27604 Fax (919) 733-9612 1-877-623-6748 Jan. 9. 2008 12:39PM hA�WEV ASSOCIATEN & ASSOCIATES, INC. 3119 P. 2 SOIL & ENVIRONMENTAL SCIENTISTS P.O. Box 400, 266 Old Coats Road Lillington, NC 27546-0400 Phone (910) 893-8743 / Pax (910) 893-3594 E-mail: halowen@earthlink.net 9 January, 2008 Mr. Glenn Tew Jordan—Tew & Associates, P.A. P.O. Box 249 Duren NC 28335 Reference: Soil Investigation for Stormwater Retention Pond Pleasant Union Christian Church. Property — 6,04 Acres Dear Mr. Tew, A site investigation has been conducted for the above referenced property, located on the eastern side of Neill's Creek Road (S.R. 1513), Neill's Creek Township, Harnett County, North Carolina. The purpose of this investigation was to determine the depth to evidence of a seasonal high water table and to determine the soil's ability to support a stormwater retention pond. All soil determinations were made in accordance with the North Carolina Stormwater Best Management Practices Manual and Stormwater Management Regulations (15A NCAC 0214.1000). All borings were performed using hand powered soil augers. The soils in the eastern comer of the property are proposed to be utilized for construction of a stormwater retention pond and are the subject of this report and the limit of the site investigation (see attached map). The soil underlying this property is described in the Soil Survey of Barnett County, North Carolina, as the Norfolk soil series and taxonomically classified as fine -loamy, siliceous, thermic, Typic Paleudults. The soils at the proposed detention pond site appear to conform well to the range in characteristics for Norfolk soil. However, the solum depths to parent materials ranged from 42 to 55 inches below surface while Norfolk soils are typically more than 60 inches deep. These well -drained soils formed from Coastal Plain sediments with surface textures of•loamy sand and subsurface textures ranging from sandy clay loams to clay loams. The surface soils were loose and the subsoils were friable. Soil characteristics indicating a seasonal high water table were observed at 42 and 43 inches below surface in the two soil borings. Apparent water table depths in the bore holes after two hours were between 48 to 50 inches. The subsoils appear adequate to support the construction of the pond to a depth of 39 inches below natural ground surface. Below this depth, the soils become much more sandy and permeabilities will likely be too high for this purpose. It should be noted that field determinations of soil permeabilities were not determined in -situ and that subsoil permeability ranges from 0.6 to 2.0 inches/hour as cited by the Soil Survey Manual of Harnett County. The sandy clay loam ,subsoils above 39 inches should compact well and provide the retention characteristics that you desire. Soil Science Investigations • Wetland Delineations, Permitting, and Consulting Jan. 9. 2008 12:40PM HAL OWEN & ASSOCIATES HAL OWEN&ASSNNo 379'. P. 3 I appreciate the opportunity to provide this service and trust that you will feel free to call on me again in the future. If you have any questions or need additional information please contact me at your convenience. Since ly, �' ��✓ Elal Owen Licensed Soil Scientist DO d, Soil Science Investigations • Wetland Delineations, Permitting, and Consulting Jan. 9. 2008 12:40PM HAL OWEN & ASSOCIATES HAL OWEN & ASSNo3 9.ES P,av4y HAL OWEN & ASSOCIATES, INC. P.O. BOX 400, LILLINGTON, NC 27546 (910) 893-8743 FAX: (910) 893-3594 PARCEL ID #: 0661-74-2799 PROPERTY RECORDED: COUNTY: Barnett SOIL PROFILE DESCRIPTION APPLICANT: Glenn Tew OWNER:® AGENT:❑ PHONE: ADDRESS: Pleasant Union Christian Church DATE EVALUATED: 20 December 2007 2164 Neill's Creek Road PROPOSED FACILITY: Church Lillington NC 27546 PROPERTY SIZE: 6.04 acres LOCATION OF SITE: Neill's Creek Road and Mamie Upchurch Road, WATER SUPPLY: On -Site Well ❑ Comm. Well ❑ Public ® EVALUATION METHOD: Auger Boring E Pit ❑ PROFH ❑ r HORIZONV DEPIH MATRIX I MOTTLES EKrURE STRUCTURE CONSISTENCE BOUNDARY Ap 0.6 10YR 5/4 None VFr LS 2 M GR NS, NP AS E 6.16 1 None VFr LS 2 M OR NS, NP CS Btl 16-26 None Fr CL 2 M SBK SS, SP GW Bt2 26-39 rOYR IOYR6/6FIDFr IOYR6/6c2FBt3 CL 2 M SBK SS, SP GW 39-42 IOYR.5/6CIDFr IovR 7/3 czPC SCL 1 M SBK SS, SP CS 42-60 10YR 718 C2P Fr LS SG NS, NP AWT 50" SHWT 42" SLOPE 2-5% ELEVATION DRAIDAG Well Drained PERMEABILITY I Moderate VEGETATION Orals/ Old field COMMENTS: Subsoils appear adequate for a wet detention pond to a d th of 39". PunFTI'F, 2 HORIZON DEPTH (IN) MATRIX MOTTLES TEXTURE STRUCTURE CONSISTENCE BOUNDARY Ap O-6 10YR 6/4 None VFr LS 2 M GR NS, NP AS E 6-13 IOYR 6/6 None VFr LS 2 M GR NS, NP AS Btl 13-17 IOYR 6/6 Nona Fr SL 1 M SBK SS, SP CS M2 1736 10YR 6/8 None MCI, 2 M SBK SS, SP GW Bt3 36-43 IOYR 7/8 MR. C21) IOYR 7/6 C2D Fr SCL 2 M SBK SS, SP GW Bt4 43-48 10YR 7/6 "' 7/3 C2D 5YR 5/6 C2P Fr SCL 1 M SBK SS, SP GW Bt5 48-55 lOYR 7/6 5 YR.516 C2P lOYR 7/2 C2P Fr SCL 1 M SBK SS, SP CS C 55-60 IOYR 7/2 IOYR816FIP Fr SCL M NS, NP AWT 48" SHWT 43" SLOPE 2-5% ELEVATION 129.5 ft DRAINAG Well drained PERMEABILITY Moderate EGETATION Grass/old field OMMENTS: rc Subsoils appear adequate for a wet pond to a depth of 43". Rain 4 1/2 Days ago, but general drought conditions. Soil very moist below 39", but no redox before 43". Investigator: Hal Owe LSS — Soil Science Investigations 0 Wetland Delineations. Permitting, and Consulting t 932O X A - LANOSCAP - ERS ALONG EDP I. — JI h — 4 5 17� I uE ;EA.�i IME - '- -jP y 4 h —4 NEW C�1 —� TOP FL 91.00 � 86. 0 h 0.�8 AC.�- - --" GOD8 T. AC. i Ip' SEfBACry i8 RIP RAP SLOPES (SEE DETAIL) TEMPORARY SILT FENCE cm(mM - OFF nFiAII ------ ---co --- TEMP \-TEMPORARY SILT FENCE AS REQUIRED SURFACE AREA-0.01010 WHEWL QID=CIA=(0.4)(7.51H/NR)(2.8AC.)-7.8 CFS ' ��SHOWN`\`� -SEE DETAIL gb REQUIRED SURFACE AREA=6.01(73CFS}(43560}=3398 SF ,f• �. �� SURFACE AREA PROYIDED=4875 SF (SHADED AREA IN FORBAD REQUIRED STORAGE=3600FT3/AC(2.6AC.)-9380 FT3 Q` STORAGE PROVIDED-12,740 SF (SHADED AREA IN FORBAY) HM CLEAN SEDIMENT FROM STORAGE ZONE WHEN 56R FULL DURIN CONSTRUCTION. WHEN UPSTREAM AREAS ARE STABLE AGAINST EROSIO =� AND PERIAISSION HAS BEEN OERAAIm F1t0lA NCDENt, RENOYE IEAW. �' •\'� SEDIMENT PR, INSTALL PERT, ON PLANS, AIo CS. o . 861N, SEED ALL DISTURBED AREAS m \ ` ,�J �- T \ m \ 8 � z 13' LEVEL SPREADER o .. � a r RIP RAP APR017 m 3- .. ....- -_.. y I USE RIP RAP d5D=6", HI DEPTH =IS- Wl-Y, W2-12', L-10' - �; INSTANT FR.TER CLO DENE4TH RIP RAP r I ( L0& A8" DIP WAN PIPE A i TOP-85.50 ` = L 4 INV-84.50 .... ::::.:--,-.......... - Ba & NEW 8" DIP DRAIiI PIPE A 0.0% 88 ° PRINCIPAL SPILLWAY o m INSTALL 3 EACH RIP RAP STRUCTURE (SEE DETAIL) - - J _RARY PERMANENT RIP RAP APRON 3 IN SEDIMENTPO 6-0BAFFLES SRIRADE (SEE DEEfHSHNI) USE RIP RAP d50=6% MIN. DEPTH=18" GRADING, D RAI N AG.E, AND ZONE AS SHOWN_ - W1-45, W2-15, L=53' SEE SAIL INSTALL FILTER CLOTH BENEATH RIP RAP EROSION CONTROL PLAN PERMANENT RIP RAP APRON$4 USE RIP RAP , MIN. oLrTH=Ta' GRAPHIC SCALE WT=4.5', W2=10'10', L=T INSTALL FILTER CLOTH BENEATH RIP RAP so 120 30 o as m i @TCIF -1717- Jordan - Tew & Associates, P.A. OCT 3 1 %oo? ENGINEERING, SURVEYING, MATERMSTES77NG & P a - WATEH QUHLI 102 We# Bored Street (Zip 28334) Wetlarge & S<orlrMatsr Br Yost Won Box 249 Limn, Nordr CaroBna 28335 Rona I Jordan, P.L.S. Pb3W (910)M5159 Johnny Glew Taw, P.E FMC L910) 892-1893 LETTER OF TRANSMITfAJI To: SfoVW Wa-Ar Ae ✓✓W4+1-vl� Un i f Date: l U O % Company: va),I-j Location : %%rryv &t�Co,. -v j0a,` Il Se✓vi a- pCen j P//✓' r7'Project Na/me ; Pl eas'a ✓f/- / `Gt 12 f A Ll IV, G e �.%%�, / '�— �b / �_ %}� N 1 iflQul C.�7 C/✓C.� We Transmit : Herewith ❑ In Accordance With Your Request The Following : CdDrawingo UPreliminaryl ❑ Test Results . UOther For Your: afApproval ❑ Use ❑ Review dt Comment ❑ Record Remarks: Transmitted IV e� yeaV d-1UlJXz4y S+WlU e. _ Copies To: eyq �novl by 4Yla.il�ihe�/ b Ju!i�� / f��eaSAN 1_iJ%1.1 c"I �1_r_fS�/ a//N�� G`NI CIL /C Cr.v.L IS /o e—Jo yt_vry vVC-✓� ! Yc ' may y`fe1t- Wi.l--� 6P K2�Je-c e f��i_jt?_e— v.��-o—��.�✓a 1 �:�5 oT ct�J a ceH f YLt.Q.l.i1 bo`Y--.GGt.HNo f_Y �pvr�os� o �Na �� �-r ra fT c e- a Pleasant Union Christian Church °�.,yta.NN,0 Harnett County, N.C. Storm Water Control Narrative & Calculations The project is located on a 6.04 acre parcel in the south east quadrant of the intersection of NCSR 1513 and NSCR 1514 in Harnett County, NC. The portion of the project that drains to the proposed storm water pond is 3.26 acres. There are no areas of off site drainage that contribute to the watershed area for the proposed pond. The project will consist of an expansion to the existing Pleasant Union Church Worship Center and will also have associated drives and parking for the expansion. The total impervious area within the drainage area for the pond is 93,608.00 sf (2.15 acres). This will result in an impervious percentage of 2.15 acres - 3.26 acres = 65.95% for the pond design. Next we determine the "average depth" of the pond by dividing the total permanent pool volume by the surface area at the permanent pool elevation as follows: 43,640 ft3 - 14,411 ft2 = 3.03 > 3.0 therefore ok Next we determine the SA/DA factor as follows: Use 65.95% Impervious for entire drainage area. Use Table 10-1 (85% TSS — Piedmont Region). Use 3.03' as average pond depth (see impervious calculations). 2.40 + 5.95 (0.48) = 2.69 Factor at 65.95yImp. (3.0' deep) 10 2.03 + 5.95 (0.37) = 2.25 Factor at 65.959 impervious (4.0' deep) 10 2.69 — (.03) 0.44 = 2.68 Factor at 65.95XImp. (3.03' deep) Therefore Required Surface Area 3.26 acres (2.68-.100) (43560 sf/ac) = 3,805.75 sf Surface area provided at permanent pool elevation of 85.5 = 14,411 sf Since 14,411 sf > 3,805.75 sf therefore ok Next we determine the required volume needed in order to store 1" design depth over the entire watershed as follows: m Using simple method we determine runoff coefficient Rv = 0.05 + 0.9 (la) where Ia = 0.6595 Rv = 0.6436 Volume of runoff to be controlled V = 3630 (R.) (Rv) (A) where Rp = I" Rv = 0.6436 A=3.26 acres = 7,616.23 113 This volume can be stored above the permanent pool elevation within a depth of 7,616.23 113=14,411 ft2 = 0.53' (Elevation 85.50 + 0.53' = 86.03') Due to the fact that the emergency spillway elevation equals 87.03 this gives a freeboard depth of 1.00 within the pond above the temporary pool elevation. Since 1.00' = 1.00 therefore ok. We have set the invert of the principal spillway pipe at the outlet structure to be 85.50, which equals the permanent pool elevation. We have set the top of the outlet structure to be at elevation 86.03', which will allow for the storage of the 1" design volume as previously calculated. The elevation of the emergency bypass swale is at 87.03. We have designed the principal spillway to have a 1 ''/2" diameter orifice to allow the temporary storage volume to flow from the pond within the allowed time span of 2-5 days as follows: First we check outflow from 1 %2" diameter orifice by using he orifice equation: Q= 0.6 A J2gh where A (1 %2" diameter)=0.0123 ft2 h= (0.53 — 0.16)-2= 0.19' g-- 32.2 Q= 0.6 (0.0123) (3.50) Q= 0.0258 efs Drawdown time = 7,616.23 113 - 0.0258 cfs = 295,202.71 sec - 60 = 4,920.05 minutes 60 = 82.0 firs - 24 = 3.41 days Since 3.41 days is between 2-5 days therefore o.k. Next we check the ratio of the forebay volume to the total permanent pool volume as follows: 8,703.73 ft3 - 43,640.91 ft3 = 20% Since this equals 20% therefore o.k. The pond travel length verses the pond width ratio is calculated as follows: �a�,;,:++sn�.,,°•• r�SFi CAR / Pond travel length = 245' ''•�0 •°'°°°°°°.. Pond width (at permanent pool elevation) = 60' Pond length - width = 4.08 { 's Since 4.08 > 3.0 therefore o.k. 45Eo p' Next we check adequacy of level spreader as follows: �''•, y °'"° . .•� Q10 design flow for level spreader = /.05cfs Minimum required length per I cfs of flow for slopes 0 to 8% = 13' (We have specified a level spreader length of 2 13') 13' = 13' therefore o.k. We have specified the top elevation of the level spreader to be 85.00 verses the outlet pipe invert elevation of 84.50. Next we check the adequacy of the filter strip as follows: Design Q10 flow = 0.036 Typical Section bmlm yt"," Ir\ Longitudinal slope = 2.5% Note: Seed Filter strip with Centipede turf grass (V max = 5 ft/sec) Assume easily erodible soils (n=0.03) Assume established centipede grass Check adequacy of filter strip as follows: D A R R2/3 n Tryd=0.25 1.88 0.103 0.218 0.03 S1/2 V Q Comment 0.158 1.71 3.2 Q> Q10 V< V allow = 1.49 A R2/3 S1/2 Q = 1.49 (1.88) (0.218) (0.158) Q = 3.2 cfs n 0.03 V=Q=A=3.2=1.88=1.71 Therefore the filter strip swale will be stable when grass is established. Since V<2.0 ft/sec there is no need for a temporary Swale liner. Next we check the emergency by-pass swale as follows: MA 20 3Mi„ � 11 Typical Section 3 �, M 3 m; n Note: Seed swale with a centipede turf grass Design Q10 = 19.56 cfs Longitudinal slope = 5% V max = 5 ft/sec (Assume easily erodible soils) n = 0.03 (Assume established centipede grass) Check adequacy of Skkk/e as follows: D A R R2/3 n Tryd=0.25 5.19 0.24 0.384 0.03 S1/2 V Q Comment 0.2236 4.26 22.13 Q>Q10 V<V allow Q= 1.49 A R2/3 S 1/2 Q = 1.49 (5.19) (0.384) (0.224) Q = 22.13 cfs N 0.03 V=Q+A=22.13=5.19=4.26Mee t Therefore the swale will be stable when grass is established. No temporary swale liner is specified due to infrequency of use. We Aaae J,,o �o�fe� fAe �eqto (19.Sl cfS) 74ro��Ir -t-Ae aV% -0e e« Lc ov40&�o -f-rG.h -"4e print;po,spi//wav o5 cca Weer ele✓af'oh p . e6.9i3 f, T!, rs is less f/jG„ -f!e enrerJc Inc /y 6y�,Ss SWq(e eIe✓Gf*oil t Ati C-4 is 87.03 ere lore Ire c�� Will ✓ovle the /o Year aC:-hvaf� rSf�t^nt �1WitAo(a tl(e ent ei 0e„cy ty/ SS S/r.✓n�2 J SPC' CA ac / l \ C 0. c v 1 a+i opt s)// l%- Qloo +be- . ,91" CAq l ••,, �0 ,........% �� yr �l/e 4ave a �so rov 11 c� Pea a rt /� [/ d Tov l l me Pear � Pay A� � 1 5 p t 8 .0 0 (/I �lo(-�% '�V'ovi( _/I�G P✓�l'!'1 �-ll of spl /�Wa� !S y C ` .,a''{.jry%y�NE�.�k.,�+�.� '. cIENN - /,'t GfS of a LLhAfev' sir �ce ete✓a rolh o^ ,",,,,t, N, 110", /OI09 OT �6•�.Z See cS�aG�e� y�avl f�1� L-u�crJ�aIIOHSI Ell Storage Indication Method Pleasant Union Church 10 Year Storm Routing 10-15-2007 Given Input Data: File ........... G:\CAD\DWG\P\PUchurch\hd\10yr.sim Description .... 10 Year Storm Routing Time increment. 0.5000 min Input Files: Pre-Dev Hydrograph curve .. Post-Dev Hydrograph curve. G:\CAD\DWG\P\PUchurch\hd\10yr.hdc Stage -Storage curve ....... G:\CAD\DWG\P\PUchurch\hd\permpool.ssc Stage -Discharge curve ..... G:\CAD\DWG\P\PUchurch\hd\8inchoutlet.sdc Output Data: Routed Peak Flow ......... 1.0453 cfs Routed Peak Time ......... 0.2833 min+' °�F$$/Q ••,? 'e Post -Developed Peak Flow . 19.5600 cfs °o • Q� y Post -Developed Peak Time. 5.0000 min Support Calculations: O. 4580 •E -------------------------------------------------------------------------------- o,,'yy� .. ; .1• Time Inflow (I1+12)/2 min cfs ft3 ft --------------------------------------------------------------------------------- HI SI-(01/2)T S2+(O2/2)T H2 Outflow ft3 ft3 ft cfs , v iG( I JEW /D� 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 85.5000 0.0000 0.5000 0.4800 7.2000 85.5000 0.0000 7.2000 85.5004 0.0010 1.0000 1.8700 35,2500 85.5004 7.1690 42.4190 85.5026 0.0061 1.5000 4.0300 88.5000 85.5026 42.2364 130.7364 85.5079 0.0188 2.0000 6.7600 161.8500 85.5079 130.1735 292.0235 85.5176 0.0419 2.5000 9.7800 248.1000 85.5176 290.7663 538.8663 85.5325 0.0773 3.0000 12.8000 338.7000 85.5325 536.5463 875.2463 85.5528 0.1256 3.5000 15.5300 424.9500 85.5528 871.4781 1296.4281 85.5782 0.1861 4.0000 17.6900 498.3000 85.5782 1290.8465 1789.1465 85.6079 0.2568 4.5000 19.0800 551.5500 85.6079 1781.4437 2332.9937 85.6407 0.3348 5.0000 19.5600 579.6000 85.6407 2322.9494 2902.5494 85.6750 0.4165 5.5000 19.0800 579.6000 85.6750 2890.0530 3469.6530 85.7092 0.4979 6.0000 17.7000 551.7000 85.7092 3454.7150 4006.4150 85.7416 0.5750 6.5000 15.6600 500.4000 85.7416 3989.1661 4489.5661 85.7707 0.6443 7.0000 13.7500 441.1500 85.7707 4470.2371 4911.3871 85.7961 0.7048 7.5000 12.0800 387.4500 85.7961 4890.2420 5277.6920 85.8182 0.7574 8.0000 10.6100 340.3500 85.8182 5254.9699 5595.3199 85.8374 0.8030 8.5000 9.3100 298.8000 85.8374 5571.2302 5870.0302 85.8540 0.8424 9.0000 8.1800 262.3500 85.8540 5844.7579 6107.1079 85.8682 0.8764 9.5000 7.1800 230.4000 85.8682 6080.8148 6311.2148 85.8806 0.9057 10.0000 6.3100 202.3500 85.8806 6284.0430 6486.3930 85.8911 0.9309 10.5000 5.5400 177.7500 85.8911 6458.4670 6636.2170 85.9002 0.9524 11.0000 4.8600 156.0000 85.9002 6607.6460 6763.6460 85.9078 0.9707 11.5000 4.2700 136.9500 85.9078 6734.5264 6871.4764 85.9143 0.9861 12.0000 3.7500 120.3000 85.9143 6841.8925 6962.1925 85.9198 0.9991 12.5000 3.2900 105.6000 85.9198 6932.2180 7037.8180 85.9244 1.0100 13,0000 2.8900 92.7000 85.9244 7007.5179 7100.2179 85.9281 1.0190 13.5000 2.5400 81.4500 85.9281 7069.6492 7151.0992 85.9312 1.0263 14.0000 2.2300 71.5500 85.9312 7120.3115 7191.8615 85.9337 1.0321 14.5000 1.9600 62.8500 85.9337 7160.8982 7223.7482 85.9356 1.0367 15.0000 1.7200 55.2000 85.9356 7192.6477 7247.8477 85.9370 1.0401 15.5000 1.5100 48.4500 85.9370 7216.6434 7265.0934 85.9381 1.0426 16.0000 1.3200 42.4500 85.9381 7233.8148 7276.2648 85.9387 1.0442 16.5000 1.1600 37.2000 85.9387 7244.9382 7282.1382 85.9391 1.0451 17.0000 1.0200 32.7000 85.9391 7250.7862 7283.4862 85.9392 1.0453 17.5000 0.9000 28.8000 85.9392 7252.1285 7280.9285 85.9390 1.0449 18,0000 0.7900 25.3500 85.9390 7249.5818 7274.9318 85.9387 1.0440 18.5000 0.6900 22.2000 85.9387 7243.6109 7265.8109 85.9381 1.0427 19.0000 0.6100 19.5000 85.9381 7234.5293 7254.0293 85.9374 1.0410 19.5000 0.5300 17.1000 85.9374 7222.7983 7239.8983 85.9366 1.0390 20.0000 0.4700 15.0000 85.9366 7208.7283 7223.7283 85.9356 1.0367 20.5000 0.4100 13.2000 85.9356 7192.6278 7205.8278 85.9345 1.0341 21.0000 03600 11.5500 85.9345 7174.8044 7186.3544 85.9333 1.0313 21.5000 0.3200 10.2000 85.9333 7155.4149 7165.6149 85.9321 1.0283 22.0000 0.2800 9.0000 85.9321 7134.7646 7143.7646 85.9308 1.0252 22.5000 0.2400 7.8000 85.9308 7113.0084 7120.8084 85.9294 1.0219 23.0000 0.2100 6.7500 85.9294 7090,1511 7096.9011 85.9279 1.0185 23.5000 0.1900 6.0000 85.9279 7066.3466 7072.3466 85.9265 1.0150 24.0000 0.1700 5.4000 85.9265 7041.8979 7047.2979 85.9249 1.0114 24.5000 0.1500 4.8000 85.9249 7016.9571 7021.7571 85.9234 1.0077 25.0000 0.1300 4.2000 85.9234 6991.5262 6995.7262 85.9218 1.0040 25.5000 0.1100 3.6000 85.9218 6965.6073 6969,2073 85.9202 1.0002 26.0000 0.1000 3.1500 85.9202 6939.2027 6942.3527 85.9186 0.9963 26.5000 0.0900 2.8500 85.9186 6912.4636 6915.3136 85.9170 0.9924 27.0000 0.0800 2.5500 85.9170 6885.5410 6888.0910 85.9153 0.9885 27.5000 0.0700 2.2500 85.9153 6858.4356 6860.6856 85.9137 0.9846 28.0000 0.0600 1.9500 85.9137 6831.1481 6833.0981 85.9120 0.9806 28.5000 0.0500 1.6500 85.9120 6803.6794 6805.3294 85.9104 0.9766 29.0000 0.0500 1.5000 85.9104 6776.0303 6777.5303 85.9087 0.9726 29.5000 0.0400 1.3500 85.9087 6748.3509 6749.7009 85.9070 0.9687 30.0000 0.0300 1.0500 85.9070 6720.6413 6721.6913 85.9053 0.9646 30.5000 0.0300 0.9000 85.9053 6692.7523 6693.6523 85.9036 0.9606 31.0000 0.0300 0.9000 85.9036 6664.8339 6665.7339 85.9019 0.9566 31.5000 0.0200 0.7500 85.9019 6637.0358 6637.7858 85.9002 0.9526 32.0000 0.0200 0.6000 85.9002 6609.2080 6609.8080 85.8986 0.9486 32.5000 0.0200 0.6000 85.8986 6581.3507 6581.9507 85.8969 0.9446 33.0000 0.0200 0.6000 85.8969 6553.6133 6554.2133 85.8952 0.9406 33.5000 0.0100 0.4500 85.8952 6525.9953 6526.4453 85.8935 0.9366 34.0000 0.0100 0.3000 85.8935 6498.3469 6498.6469 85.8919 0.9326 34.5000 0.0000 0.1500.85.8919 6470.6681 6470.8181 85.8902 0.9286 Storage Indication Method Pleasant Union Church 100 Year Storm Routing 10-29-2007 Storage Indication Method Given Input Data: File ........... G:\CAD\DWG\P\PUchurch\hd\100yr.sim Description .... 100 Year Storm Routing Time increment. 0.5000 min Input Files: Pre-Dev Hydrograph curve .. Post-Dev Hydrograph curve. G:\CAD\DWG\P\PUchurch\hd\100yr.hdc Stage -Storage curve ....... G:\CAD\DWG\P\PUchurch\hd\permpool.ssc Stage -Discharge curve ..... G:\CAD\DWG\P\PUchurch\hd\8inchoutlet.sdc Output Data Routed Peak Flow ......... 1.2130 cfs Routed Peak Time ......... 0.2833 min Post -Developed Peak Flow. 23.4700 cfs Post -Developed Peak Time. 5.0000 min Support Calculations: Time Inflow (I1+I2)/2 H1 Sl-(0I/2)T S2+(O2/2)T H2 Outflow min cfs ft3 It ft3 ft3 ft cfs 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 85.5000 0.0000 0.5000 0.5700 8.5500 85.5000 0.0000 8.5500 85.5005 0.0012 1.0000 2.2400 42.1500 85.5005 8.5132 50.6632 85.5031 0.0073 1.5000 4.8400 106.2000 85.5031 50.4451 156.6451 85.5094 0.0225 2.0000 8.1100 194.2500 85.5094 155.9707 350.2207 85.5211 0.0503 2.5000 11.7400 297.7500 85.5211 348.7128 646.4628 85.5390 0.0928 3.0000 15.3600 406.5000 85.5390 643.6796 1050.1796 85.5633 0.1507 3.5000 18.6300 509.8500 85.5633 1045.6583 1555.5083 85.5938 0.2232 4.0000 21.2300 597.9000 85.5938 1548.8113 2146.7113 85.6294 0.3081 4.5000 22.9000 661.9500 85.6294 2137.4690 2799.4190 85.6688 0.4017 5.0000 23.4700 695.5500 85.6688 2787.3666 3482.9166 85.7100 0.4998 5.5000 22.9000 695.5500 85.7100 3467.9216 4163.4716 85.7511 0.5975 6.0000 21.2400 662.1000 85.7511 4145.5465 4807.6465 85.7899 0.6899 6.5000 18.8000 600.6000 85.7899 4786.9480 5387.5480 85.8249 0.7732 7.0000 16.5000 529.5000 85.8249 5364.3529 5893.8529 85.8554 0.8458 7.5000 14.4900 464.8500 85.8554 5868.4780 6333.3280 85.8819 0.9089 8.0000 12.7300 408.3000 85.8819 6306.0610 6714.3610 85.9049 0.9636 8.5000 11.1700 358.5000 85.9049 6685.4535 7043.9535 85.9247 1.0109 9.0000 9.8100 314.7000 85.9247 7013.6271 7328.3271 85.9419 1.0517 9.5000 8.6200 276.4500 85.9419 7296.7763 7573.2263 85.9567 1.0868 10.0000 7.5700 242.8500 85.9567 7540.6211 7783.4711 85.9693 1.1170 10.5000 6.6400 213.1500 85.9693 7749.9608 7963.1108 85.9802 1.1428 11.0000 5.8300 187.0500 85.9802 7928.8271 8115.8771 85.9894 1.1647 11.5000 5.1200 164.2500 85.9894 8080.9356 8245.1856 85.9972 1.1833 12.0000 4.5000 144.3000 85.9972 8209.6875 8353.9875 86.0032 1.1931 ,�rzq�o7 12.5000 3.9500 126.7500 86.0032 8318.2048 8444.9548 86.0078 1.1977 13.0000 3.4700 111.3000 86.0078 8409.0507 8520.3507 86.0117 1.2015 13.5000 3.0500 97.8000 86.0117 8484.3459 8582.1459 86.0149 1.2046 14.0000 2.6700 85.8000 86,0149 8546.0586 8631.8586 86.0174 1.2071 14.5000 2.3500 75.3000 86.0174 8595.7050 8671.0050 86.0194 1.2091 15.0000 2.0600 66.1500 86.0194 8634.7991 8700.9491 86.0210 1.2106 15.5000 1.8100 58.0500 86.0210 8664.7032 8722.7532 86.0221 1.2117 16.0000 1.5900 51.0000 86.0221 8686.4782 8737.4782 86.0229 1.2124 16.5000 1.4000 44.8500 86.0229 8701.1836 8746.0336 86.0233 1.2128 17.0000 1.2300 39.4500 86.0233 8709.7275 8749.1775 86.0235 1.2130 17.5000 1.0800 34.6500 86.0235 8712.8672 8747.5172 86.0234 1.2129 .18.0000 0.9500 30.4500 86.0234 8711.2092 8741.6592 86.0231 1.2126 18.5000 0.8300 26.7000 86.0231 8705.3590 8732.0590 86.0226 1.2121 19.0000 0.7300 23.4000 86.0226 8695.7716 8719.1716 86.0219 1.2115 19.5000 0.6400 20.5500 86.0219 8682.9013 8703.4513 86.0211 1.2107 20.0000 0.5600 18.0000 86.0211 8667.2021 8685.2021 86.0202 1.2098 20.5000 0.4900 15.7500 86.0202 8648.9773 8664.7273 86.0191 1.2087 21.0000 0.4300 13.8000 86.0191 8628.5297 8642.3297 86.0180 1.2076 21.5000 0.3800 12.1500 86.0180 8606.1621 8618.3121 86.0167 1.2064 22.0000 0.3300 10.6500 86.0167 8582.1766 8592.8266 86.0154 1.2051 22,5000 0.2900 9.3000 86.0154 8556.7250 8566.0250 86.0141 1.2038 23.0000 0.2600 8.2500 86.0141 8529.9593 8538.2093 86.0126 1.2024 23.5000 0.2300 7.3500 86,0126 8502.1807 8509.5307 86.0112 1.2009 24.0000 0.2000 6.4500 86.0112 8473.5404 8479.9904 86.0096 1.1994 24.5000 0.1700 5.5500 86.0096 8444.0395 8449.5895 86.0081 1.1979 25.0000 0.1500 4.8000 86.0081 8413.6792 8418.4792 86.0065 1.1964 25.5000 0.1300 4.2000 86.0065 8382.6104 8386.8104 86.0049 1.1948 26.0000 0.1200 3.7500 86.0049 8350.9839 8354.7339 86.0032 1.1932 26.5000 0.1000 3.3000 86.0032 8318.9503 8322.2503 86.0015 1.1915 27.0000 0.0900 2.8500 86.0015 8286.5100 8289,3600 85.9998 1.1896 27.5000 0.0800 2.5500 85.9998 8253.6716 8256.2216 85.9978 1.1849 28.0000 0.0700 2.2500 85.9978 8220.6759 8222.9259 85.9958 1.1801 28.5000 0.0600 1.9500 85.9958 8187.5236 8189.4736 85.9938 1.1753 29.0000 0.0500 1.6500 85.9938 8154,2153 8155.8653 85.9918 1.1705 29.5000 0.0500 1.5000 85.9918 8120.7517 8122.2517 85.9898 1.1656 30.0000 0.0400 1.3500 85.9898 8087,2828 8088.6328 85.9877 1.1608 30.5000 0.0400 1.2000 85.9877 8053.8087 8055.0087 85.9857 1.1560 31.0000 0.0300 1.0500 85.9857 8020.3293 8021.3793 85.9837 1.1512 31.5000 0.0300 0.9000 85.9837 7986.8447 7987.7447 85.9816 1.1463 32.0000 0.0200 0.7500 85.9816 7953.3549 7954.1049 85.9796 1.1415 32.5000 0.0200 0.6000 85.9796 7919,8600 7920.4600 85.9776 1.1367 33.0000 0.0200 0.6000 85.9776 7886.3598 7886.9598 85.9756 1.1319 33.5000 0.0200 0.6000 85.9756 7853.0040 7853.6040 85.9736 1.1271 34.0000 0.0100 0.4500 85.9736 7819.7917 7820.2417 85.9715 1.1223 34.5000 0.0000 0.1500 85.9715 7786.5731 7786.7231 85,9695 1.1175 GLENN "•mllits I ` I I ` I ` 1 � I � I j 1 I I I I I I I I I I i #Units=OevaUon,ft,Volume,ft3 #Stage —Storage Curve Data #Stage — ft Volume — ft3 # 85.50000000, 8703.72947537 85.00000000, 7060.77443935 84.00000000, 4660.85397001 83.00000000. 2832.50999244 82.00000D00, 1498.57013307 81.00000000, 580.46850259 80.00000000, 0.00D00000 forboy %=20 s.a. 0 85,514411 sf pens pool vol=43Wcf average depth=3.0 I /Units=ElevaGon,ft,Volume,ft3 #Stage —Storage Curve Data #Stage — ft Volume — ft3 #------------ ---------- 85.50000000, 34937.17636654 85.00000000, 30237.83428596 84.00000000, 22619.68052763 83.00000000, 16232.26399788 82.00000000, 10996.97102381 81.00000000, 6834.83602349 80.00000000, 3666.87495948 79.00000000. 1414.6391 ""' 78.00000000. 0.0001 4' 1 580 <il.BNN Sr`•P /orzq�o7 _i; � r �, �� �: .%�y 1. 0✓ ," i^L c G' i j - 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. Applicants name (specify the name of the corporation, individual, etc. who owns the project): Pleasant Union Christian Church 2. Print Owner/Signing Official's name and title (person legally responsible for facility and compliance): Elliott Brown (Chairman of Expansion Committee) 3. Mailing Address for person listed in item 2 above: 2164 Neill's Crppk Rnad State: rvU Telephone Number: ( 910 ) 893-4490 4. Project Name (subdivision, facility, or establishment name - should be co6sistent with project name on plans, specifications, letters, operation and maintenance agreements, etc.): Pleasant Union Christian Church 5. Location of Project (street address) 2164 Neill's Creek Road City: Lillington, NC 27546 County: Harnett 6. Directions to project (from nearest major intersection): Take Hwy 421 North from Dunn toward Lillington. Turn right on SR 1513 (Neill's Creek Road). Project is at intersection of NCSR 1513 8nkh NCSR 1514 (Mamie pe urc oa 7. Latitude: 35.4389 ' Longitude: 78.77430 of project 8. Contact person who can answer questions about the project: Name: Glenn Tew Telephone Number: L 910 ) 892-5159 II. PERMIT INFORMATION: 1. Specify whether project is (check one): x New Renewal Modification Form SWU-101 Version 3.99 Page I of 2. If this application is being submitted as the result of a renewal or modification to an existing permit, list the existing permit number N/A and its issue date (if known) 3. Specify the type of project (check one): _Low Density X High Density _Redevelop _General Permit _Other 4. Additional Project Requirements (check applicable blanks): _CAMA Major X Sedimentation/Erosion Control _404/401 Permit _NPDES Stormwater Information on required state permits can be obtained by contacting the Customer Service Center at 1-877-623-6749. III. PROJECT INFORMATION 1. In the space provided below, summarize how stormwater will be treated. Also attach a detailed narrative (one to two pages) describing stormwater management for the project. Storm water will be collected on site from all imoervinus areas by a Series of drop inlets and swales and be transported by swalesetpd gravity storm pipes to a permanent on -site wet detention pond. 2. Stormwater runoff from this project drains to the 3. Total Project Area: 3.26 acres Cape Fear 5. How many drainage areas does the project have? 1 River basin. 4. Project Built Upon Area: % 5.9 s % 6. Complete the following information for each drainage area. If there are more than two drainage areas in the project, attach an additional sheet with the information for each area provided in the same format as below. Basin Information, . Drainage Area 1 ',Drainage Area 2 .; Receiving Stream Name UT to West Buies Creek Receiving Stream Class Drainage Area 3.26 ac (142,0065 sf) Existing Impervious" Area Proposed Impervious*Area Impervious" Area (total) 65.95 Impervious" Surface Area Drainage Area I Drainage Area 2 On -site Buildings On -site Streets 0.835 ac) (36,377 sf) On -site Parking 0.569 ac) (24,787 sf) On -site Sidewalks Other on -site 0.128 ac) (5,582 sf ) Off -site Total: Total: Impervious area is defined as the built upon area including, but not limited to, buildings, roads, parking areas, sidewalks, gravel areas, etc. Form SWU-101 Version 3.99 Page 2 of 4 7. % IV How was the off -site impervious area listed above derived? DEED RESTRICTIONS AND PROTECTIVE COVENANTS The following italicized deed restrictions and protective covenants are required to be recorded for all subdivisions, outparcels and future development prior to the sale of any lot. If lot sizes vary significantly, a table listing each lot number, size and the allowable built -upon area for each lot must be provided as an attachment. 1. The following covenants are intended to ensure ongoing compliance with state stormwater management permit number as issued by the Division of Water Quality. These covenants may not be changed or deleted without the consent of the State. 2. No more than square feet of any lot shall be covered by structures or impervious materials. Impervious materials include asphalt, gravel, concrete, brick, stone, slate or similar material but do not include wood decking or the water surface of swimming pools. 3. Swales shall not be Filled in, piped, or altered except as necessary to provide driveway crossings. 4. Built -upon area in excess of the permitted amount requires a state stormwater management permit modification prior to construction. 5. All permitted runoff from outparcels or future development shall be directed into the permitted stormwater control system. These connections to the stormwater control system shall be performed in a manner that maintains the integrity and performance of the system as permitted. By your signature below, you certify that the recorded deed restrictions and protective covenants for this project shall include all the applicable items required above, that the covenants will be binding on all parties and persons claiming under them, that they will run with the land, that the required covenants cannot be changed or deleted without concurrence from the State, and that they will be recorded prior to the sale of any lot. V. SUPPLEMENT FORMS The applicable state stormwater management permit supplement form(s) listed below must be submitted for each BMP specified for this project. Contact the Stormwater and General Permits Unit at (919) 733-5083 for the status and availability of these forms. Form SWU-102 Wet Detention Basin Supplement Form SWU-103 Infiltration Basin Supplement Form SWU-104 Low Density Supplement Form SWU-105 Curb Outlet System Supplement Form SWU-106 Off -Site System Supplement Form SWU-107 Underground Infiltration Trench Supplement Form SWU-108 Neuse River Basin Supplement Form SWU-109 Innovative Best Management Practice Supplement Form SWU-101 Version 3.99 Page 3 of 4 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. The complete application package should be submitted to the appropriate DWQ Regional Office. f 1. Please indicate that you have provided the following required information by initialing in the space provided next to each item. k 0 G� Initials • Original and one copy of the Stormwater anagement Permit Application Form • One copy of the applicable Supplement orm(s) for each BMP • Permit application processing fee of $ (payable to NCDENR) A . T • Detailed narrative description of Stormwater treatment/management /a , T. • Two copies of plans and specifications, including: /j . T, - Development/Project name - Engineer and firm -Legend - North arrow - Scale - Revision number & date - Mean high water line - Dimensioned property/project boundary - Location map with named streets or NCSR numbers - Original contours, proposed contours, spot elevations, finished Floor elevations - Details of roads, drainage features, collection systems, and stormwater control measures - Wetlands delineated, or a note on plans that none exist - Existing drainage (including off -site), drainage easements, pipe sizes, runoff calculations - Drainage areas delineated - Vegetated buffers (where required) VII. AGENT AUTHORIZATION If you wish to designate authority to another individual or firm so that they may provide information on your behalf, please complete this section. Designated agent (individual or firm) Mailing Address: PO Box 249 City:_ Dunn VIII. APPLICANT'S CERTIFICATION Jordan-Tew & Associates, PA State: NC Zip: Fax: ( 910 ) 892-1893 I, (print or type name of person listed in General Information, item 2) Eliott Brown (Chairman of Expansion certify that the information included on this permit application form is, to the best of myVnoMv e ge. 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 15A nvrAr' 9u innn Date:. d0 -%-7 � ! . V / Form SWU-101 Version 3.99 Page 4 of 4 Permit No. (to be provided by DWQ) State of North Carolina Department of Environment and Natural Resources Division of Water Quality STORMWATER MANAGEMENT PERMIT APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form may be photocopied for use as an original DWO Stormwater Management Plan Review: A complete stormwater management plan submittal includes an application form, a wet detention basin supplement for each basin, design calculations, and plans and specifications showing all basin and outlet structure details. I. PROJECT INFORMATION Project Name: Pleasant Union Christian Church Contact Person: Glenn Tew Phone Number: ( 910 ) 892-5159 For projects with multiple basins, specify which basin this worksheet applies to: elevations Basin Bottom Elevation 78.00 ft. Permanent Pool Elevation 85 50 ft. Temporary Pool Elevation 86.03 ft areas Permanent Pool Surface Area 14,411_ sq. ft. Drainage Area Impervious Area volumes Permanent Pool Volume Temporary Pool Volume Forebay Volume Other parameters SA/DAI Diameter of Orifice Design Rainfall Design TSS Removal 2 3.26 ac. 2.1 5 ac. (floor of the basin) (elevation of the orifice) (elevation of the discharge structure overflow) (water surface area at the orifice elevation) (on -site and off -site drainage to the basin) (on -site and off -site drainage to the basin) 43,640.91 cu. ft. (combined volume of main basin and forebay) 7,616.23 cu. ft. (volume detained above the permanent pool) 8,703.73 cu. ft. (approximately 20% of total volume) 2.68 (surface area to drainage area ratio from DWQ table) 1.5 in. (2 to 5 day temporary pool draw -down required) 1 in. 85 % (minimum 85% required) Form SWU-102 Rev 3.99 Page I of 4 7 When using the Division SA/DA tables, the correct SA/DA ratio for permanent pool sizing should be computed based upon the actual impervious % and permanent pool depth. Linear interpolation should be employed to determine the correct value for non- standard table entries. 2 In the 20 coastal counties, the requirement for a vegetative filter may be waived if the wet detention basin is designed to provide 90% TSS removal. The NCDENR BMP manual provides design tables for both 85% TSS removal and 90% TSS removal. II. REQUIRED ITEMS CHECKLIST The following checklist outlines design requirements per the Stormwater Best Management Practices Manual (N.C. Department of Environment, Health and Natural Resources, February 1999) and Administrative Code Section: 15 A NCAC 2H .1008. Initial in the space provided to indicate the following design requirements have been met and supporting documentation is attached. If the applicant has designated an agent in the Stormwater Management Permit Application Form, the agent may initial below. If a requirement has not been met, attach justification. Applicants Initials Q : % . a. The permanent pool depth is between 3 and 6 feet (required minimum of 3 feet). .7� b. The forebay volume is approximately equal to 20% of the basin volume. 11:7 c. The temporary pool controls runoff from the design storm event. .T. d. The temporary pool draws down in 2 to 5 days. e. If required, a 30-foot vegetative, filter is provided at the outlet (include non -erosive flow calculations) A,T. f. The basin length to width ratio is greater than 3:1. 4 :T g. The basin side slopes above the permanent pool are no steeper than 3:1. A .1 h. A submerged and vegetated perimeter shelf with a slope of 6:1 or less (show detail). /l :T, i. Vegetative cover above the permanent pool elevation is specified. A ;T j. A trash rack or similar device is provided for both the overflow and orifice. �t Seer/i��P� k. A recorded drainage easement is provided for each basin including access to nearest right- ] ✓.�l1 I f 16,1 s of -way. A, 1. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified prior to use as a wet detention basin. d See afi-r dP,-,9 m. A mechanism is specified which will drain the basin for maintenance or an emergency. J vYfi' III. WET DETENTION BASIN OPERATION AND MAINTENANCE AGREEMENT The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if one is provided. This system (check one) 0 does 0 does not incorporate a vegetated filter at the outlet. This system (check one) 0 does ® does not incorporate pretreatment other than a forebay. Form SWU-102 Rev 3.99 Page 2 of 4 activities shall be performed as follows: After every significant runoff producing rainfall event and at least monthly: a. Inspect the wet detention basin system for sediment accumulation, erosion, trash accumulation, vegetated cover, and general condition. b. Check and clear the orifice of any obstructions such that drawdown of the temporary pool occurs within 2 to 5 days as designed. 2. Repair eroded areas immediately, re -seed as necessary to maintain good vegetative cover, mow vegetative cover to maintain a maximum height of six inches, and remove trash as needed. 3. Inspect and repair the collection system (i.e. catch basins, piping, swales, riprap, etc.) quarterly to maintain proper functioning. 4. Remove accumulated sediment from the wet detention basin system semi-annually or when depth is reduced to 75% of the original design depth (see diagram below). Removed sediment shall be disposed of in an appropriate manner and shall be handled in a manner that will not adversely impact water quality (i.e. stockpiling near a wet detention basin or stream, etc.). The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the permanent pool depth reads 79.88 feet in the main pond, the sediment shall be removed. When the permanent pool depth reads 81.38feet in the forebay, the sediment shall be removed. BASIN DIAGRAM (fill in the blanks) Permanent Pool Elevation 85.50 / Sediment Re oval El. 81.38 75 0 79 . S8 - - -Sediment Removal Elevation 75% -tio---------- -- ___ ----------- ---- Bottom Ele anon 80.00 % 78.00 25% Bottom Elevation FOREBAY MAIN POND 5. Remove cattails and other indigenous wetland plants when they cover 50% of the basin surface. These plants shall be encouraged to grow along the vegetated shelf and forebay berm. 6. If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain shall be minimized to the maximum extent practical. Form SWU-102 Rev 3.99 Page 3 of 4 All components of the wet detention basin system shall be maintained in good working order. I acknowledge and agree by my signature below that I am responsible for the performance of the seven 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. Print name: Eliott Brown Chairman of Expansion Committee Address: 2164 Neill's Creek Road Lillington, NC 27546 ­ - - ,. I � 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. 1, �"Cnn 9 �rcJyU�� , a Notary Public for the State of 11ur{h�ra1 �, County of 59MQri do hereby certify that G&^4 W,OW dry''"'" personally appeared before me this -�25 day of Oc'�)ber , .2ov7 , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, SEAL My commission expires rh pW a040 Form S WU-102 Rev 3.99 Page 4 of 4 kil-C- f G� +_-._ _._.._.I.1r.� eel �•�...��:�1 C c,✓_;_l� �2�.vYl_R,.iD.�c,�.np� b�/ - C_r.1v-L1.� IlS I o Ga'T�Pc� O t1—� WGI�I -l�Y- ra.i.vt a � e ���±f�r_-� _w d.t:a-i_✓.1 ��1 r_____l."_ !e _�LI./4.i.✓.1 �PY Ganno% b.�.—.%i1,S_"id.��Gd_> ._.�N.avl�—�— - ra k C e - - fI i