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HomeMy WebLinkAbout00070389Design Report Proposed Sanitary Sewer Line Improvements for Castlegate Subdivision Section 2, Phase 1 College Station, Texas November 2000 Prepared By: TEXCON General Contractors 1707 Graham Road College Station, Texas 77845 (979) 690-7711 REVIEWED FOR DEC 0 r, 2000 ENGNEEf ING : IF- OF Td®'~ ~P ..........,Ft !0 ,t J JCSEPH-P. SCHULTZ o 65889 ;~r a~~ : ~STF E.. ti II -Z-1-00 1.0 INTRODUCTION & DESCRIPTION The purpose of this report is to provide a description of the proposed sanitary sewer to be constructed with the Castlegate Subdivision, Section 2, Phase 1, and to provide the criteria used in the design of this sanitary sewer system. The project will include the construction of approximately 2625 feet of sanitary sewer line. The line will service the proposed development of the Castlegate Subdivision, Section 2, Phase 1, as well as the future development of Section 2, Phase 2. 2.0 SANITARY SEWER - Design Flow and Pipe Size Calculations The proposed sewer line is to be constructed of 6" and 8" diameter SDR-26, PVC pipe which meets the requirements of ASTM-D3034. The proposed manholes are 4' diameter manholes, and vary from 9' to 12' in depth, with sewer line slopes ranging from 0.60% to 3.75%. The maximum distance between manholes is less than 500 feet, as required by the Texas Natural Conservation Commission (TNRCC). The minimum allowable slopes for 8" and 6" pipes per TNRCC requirements are 0.33% and 0.50% respectively. All construction shall meet the current City of College Station Standard Specifications for Sanitary Sewer Construction. The sewer line information is summarized in Table 1. 3.0 DETERMINATION OF PEAK FLOW VALUES The peak flows were based on using a daily use of 300 gallons per day for each dwelling unit. The design peak flow is determined by multiplying the average daily flow by 1.5, which results in the adjusted daily flow. This value is then multiplied by 3.0 to determine the peak hourly flow. The velocities for the lines were calculated using Manning's Equation. According to the TNRCC, the minimum velocity for sewer systems flowing full is 2.0 feet per second. As shown in Table 1, the minimum anticipated flow velocities for the proposed sewer lines at 50% full meet this requirement. The flow for 100% full will not be less than the flow for 50% full; therefore, the TNRCC requirement is met. The TNRCC requires that the maximum velocity for sewer systems flow full not exceed 10 feet per second. The values in Table 1 are well below this maximum velocity. TABLE I - SEWER LINE FLOW DATA 16 Manhole No. of Units From Cumulative Average Percent 50% Full Z m Number Size Length Dwelling Unit Merging Dwelling Daily Flow Peak Flow Full Flow Velocity c J From To (in) (ft) g services Lines Units (gpm) (Cfs) (Cfs) WS) (fps) 207 206 6 230.40 3.7 3 3 0.62 0.0003 0.0013 2.6 0.5433 5.5 206 205 6 313.60 1.30 5 8 1.67 0.0008 0.0035 5.3 0.3199 3.3 205 204 8 237.50 0.60 5 13 2.71 0.0013 0.0057 _ 5.6 0.4680 2.7 c~ 204 203 8 166.60 0.75 2 _ - 15 3.12 0.0014 0.0065 5.6 0.5233 3.0 Cn 203 202 8 268.00 0.75 8 23 4.79 0.0022 0.0100 6.9 0.5233 3.0 202 201 8 169.10 0.75 2 - 25 5.21 0.0024 0.0109 7.2 0.5233 3.0 201 S-109 8 161.70 1.00 4 29 6.04 0.0028 0.0126 7.2 0.6042 3.5 212 211 6 313.00 1.50 8 8 1.67 0.0008 0.0035 5.1 0.3436 3.5 211 210 6 125.00 1.50 4 12 2.50 0.0012 0.0052 6.2 0.3436 3.5 210 209 6 174.60 2.00 4 16 3.33 0.0015 0.0070 6.7 0.3968 4.0- 04 N 209 208 8 194.00 1.50 2 18 3.75 0.0017 0.0078 5.2 0.7400 4.2 Future Development to Manhole 208 11 - 29 6.04 0.0028 0.0126 - - 208 S-111 8 270.10 1.30 5 22 (s-1t t ) 56 11.66 0.0054 0.0244 9.2 0.3199 3.3 Future Development to Manhole S-111 22 - 22 4.58 0.0021 0.0096 - - Sewer Line 53-3 has been addressed previously in the sewer report for Section 4 n = 0.013 Refer to construction drawings for manhole locations. 4.0 CONCLUSIONS It is our determination based on the criteria and data developed that the proposed sewer line will provide sufficient capacity for the anticipated wastewater flows generated by this development and the development of Section 2, Phase 2. Form Approved. OMl3 THIS FORM REPLACES PREVIOUS FORM 3510-6 (8-98) See Reverse for Instructions United Stales Envirorurwntal Protection Agency Washington, DC 20460 NPOES `L'wl EPA Notlce of tntent (NOI) for Storm Water Discharges Associated with FORM \ CONSTRUCTION ACTIVITY Under a NPOES General Permit Submission of this Notice of Intent constitutes notice that the party identified in Section I of this form intends to be authorized by a NPOES lot storm water discharges associated with construction activity in the StateAndian Country Land identified in Section it of this form. Submissio, of intent also constitutes notice that the party Identified in Section 1 of this form meets the eligibility requirements in Part I.B. of the general po those related to protection of endangered species determined through the procedures in Addendum A of the general permit). undorstands authorization to discharge Is contingent on maintaining permit eliigubifuty, and that implementation of the Storm Water Pollution Prevention Plan Part IV of the general permit Yip begin at the time the permittee commences work on the construction project idontifiod in Secan 11 below. i OBTAIN AUTHORIZATION. ALL INFORMATION REQUESTED MUST BE INCLUDED ON THIS FORM. SEE INSTRUCTIONS ON BAC OwnadOperator (Appllcant`~) Information pp p DD -7 q n Name: 1116&G101wm"I I~I~INI~11~1~1L1 1~)~It`'1T1~1~ILIT1~1~151 I 1 I Phone: L1LL11L61?L Q Status of Address- 111 0111 IN A[ p (trt 141 N6 910 1 A 1Q1 I I I I~ I I I I I I I I 1 -L -J OwnedOperat~ City IGoI~~-1 b 1V1~1 1 Sl~l~l~ld i91ro 1 1 1 1 1 1 1 1 State: Tip Code: 17171a14-I51- IL ProlectfSlte trdormatlon is the tacility local Country Lands? 1CJA5 1T, ~J f 16IAITIKI 1-51u,11,61 , of Zi S III DINT I I 1 1 1 1 -L J I Yes project Name: D & V lc c le- I ~1 y 14 1 k I It I' I I I P I r 10"1 i I I' I C I I RI 0 A t0 I I I I. 10 I ~-c . ( I ProjectAddress/Location: I(y I ' ( " , I y 7 7 S- ~ di 1 ( 1 1 1 1 i5iTAT11e), l Tpc Stale: 1 1 1 ode: cay: 2 ~ nr 3 fl I 161710) I IS o e t" 1^1`~fZt tSl 1 nt C 1 1 1 1 1 1 1 ICI l Latitude: (101 I I Longitude: ou y Has the Storm Water Pollution Prevention Plan (SWPPP) been prepared? Yes m No ❑ Optional: Address o (location of SWPPP for viewing ~ress in Section I above ❑ Address in Section 11 above ❑ Other address (if k WPPP Phone: S Address: 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1( 1 1 pp 1 1 I 1 I -J State: I zip Code: ( I I I 1 1- Name of Receiving Water: 1 S t PI RJ NI GI I C4 FdC-l EI KI 11 I 1 1 I 1 I 1 I I/f0101~IZ lolot0l Mont, ow ww Estimated Construction Start Date 1011111014010111 Alonm oar Year Estimated Completion Date 1 Estimated area to be disturbed (to nearest ac(e): L 1 1 1 1215 Estimate of LikeHmood o(Discharge (choose only one): t. ❑ Unlikely 2. ❑ Once per month 3. ROnce per week 4. ❑ Once poi day S. ❑ Continual Based on kistnxtion provided in Addendum A of IN there any fisted endangered or threatened species. critical habitat in the project area? Yes E] No~ 1 have satisfied permit e69bi6ly with regard to prote• endangered spades through the indicated section of I of the petmit (che& one or more boxes): (a) &K1*'-(b) ❑ (c) ❑ (d) ❑ 111. Certification I cattily under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance Y designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or manage this system. or those persons directly responsible lot gathering the information. the information submitted is. to the best of my kr belief, true. aoarate. and complete. 1 am aware that there are significant penalties for submitting false information. including the possibil' imodsormeM for knowino violations. Print Name: Signature: T Date: TAL -t-41 EPA Form 3510-9 replaced 35io6 (8-98) fffkCO~N General Contractors Div. gt'CDS Enterprises, Inc. 1707 Graham Rd. • College Station, TX 77845 • 409-690-7711 • Fax: 409-690-9797 December 20, 2000 Bridgette George Asst. Development Coordinator City of College Station 1101 Texas Avenue South College Station, TX 77842 RE: Castlegate Subdivision, Section 2, Phase 1 - College Station, Texas Dear Ms. George: Attached are 10 copies of the revised Final Plat, the revised mylar original, 5 revised copies of the construction documents, 2 revised drainage reports, and the "redlined" copy of the construction documents. Also attached is a summary of our response to the Staff Review Comments. If you have any questions or need additional information, please do not hesitate to give me a call at (979) 690-7711. Sincerely Yours, Joe Schultz, P.E. Civil Engineer Attachments FTCEP~STION DEVELOPMENT SERVICES TRANSMITTAL LETTER Name/Firm: -T-e C n y-t - o Date: 1 ~ - 22 - Zso O Address: \-I()- l [-~~a~a>nn Phone: (AID - I] I I r11\k.0A0 CIVA~111 n "fX Fax: [ago - 9791 We are transmitting the following for Development Services to review and comment: (Check all that apply.): ❑ Master Development Plan ❑ Preliminary Plat El Final Plat ❑ FEMA CLOMA/CLOMR/LOMA/LOMR ❑ Site Plan ❑ Grading Plan ❑ Landscape Plan ❑ Irrigation Plan ❑ Building Construction Documents w/ ❑ Redlines Development Permit App. w/ ❑ Redlines ❑ Conditional Use Permit w/ ❑ Redlines ❑ Rezoning Application w/ ❑ Redlines ❑ Variance Request w/ ❑ Redlines ❑ Other - Please specify w/ ❑ Redlines w/ ❑ Redlines w/ ❑ Redlines w/ ❑ Redlines YRASTRUCTURE AND ENGINEERING DOCUMENTS All infrastructure documents must be submitted as a complete set. The following are included in the complete set: Waterline Construction Documents w/ ❑ Redlines UrSewerline Construction Documents w/❑ Redlines @' Drainage Construction Documents w/ ❑ Redlines Street Construction Documents w/ ❑ Redlines ❑ Easement application with metes & bounds decsription U Drainage Letter or Report w/ ❑ Redlines ff-Fire Flow Analysis See -§eC on Ij Ph a- w/ ❑ Redlines 1.~ Se~1er ~.~~~Tn Special Instructions: ❑ TxDOT Driveway Permit ❑ TxDOT Utility Permit ❑ Other - Please specify TRANSMrrrAL LETTER 1 of I TRANSMrr.DOC 03/23/99