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Sanitary Sewer • Design Report Proposed Sanitary Sewer Line Improvements for South Hampton Subdivision — Phase 3 College Station, Texas May 2004 Prepared By: TEXCON General Contractors 1707 Graham Road College Station, Texas 77845 (979) 764 -7743 °,%P E O . ••F : t • * • ' . * JOSEPH P. SAUL �1 1.0 INTRODUCTION & DESCRIPTION The purpose of this report is to provide a description of the proposed sanitary sewer to be constructed with the South Hampton Subdivision Phase 3, and to provide the criteria used in the design of this sanitary sewer system. The location of the sewer lines are shown on Exhibit A. The project will include the construction of approximately 147 feet of sanitary sewer line. The line will service the proposed development of the South Hampton Subdivision, Phase 3. 2.0 SANITARY SEWER - Design Flow and Pipe Size Calculations The proposed sewer line is to be constructed of 6" diameter SDR -26, PVC pipe which meets the requirements of ASTM- D3034. The proposed manhole is a 4' diameter manhole, and is 7' in depth, with a sewer line slope of 1.34 %. The maximum distance between manholes is less than 500 feet, as required by the Texas Commission on Environmental Quality (TCEQ). The minimum slope per the Bryan/College Station Design Guidelines is 0.8 %. The minimum allowable slope for 6" pipes per TCEQ requirements is 0.50 %. All construction shall meet the current Bryan/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 4.0 to determine the peak hourly flow. The velocities for the lines were calculated using Manning's Equation. According to the TCEQ, 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 TCEQ requirement is met. The TCEQ requires that the maximum velocity for sewer systems flowing full not exceed 10 feet per second. The values in Table 1 are well below this maximum velocity. TABLE 1 - SEWER LINE FLOW DATA Manhole No. of Units From Cumulative Average Percent 50% Full Size Length Slope Peak Flow Number Line # Dwelling Unit Merging Dwelling Daily Flow Full Flow Velocity From To (in) (ft) ( %) Services Lines Units (gpm) (cfs) (cfs) ( %) (cfs) (fps) MH1 E8 S -1 6 147.0 1.95 7 - 7 1.46 0.0032 0.0130 9.3 0.3638 3.7 E8 E4 E -9 6 352.0 1.34 4 S -1 11 2.29 0.0051 0.0204 12.6 0.3016 3.1 I E10 I E6 I E -8 16 I 276.0 I 1.95 I 7 1 - 1 7 I 1.46 1 0.00321 0.0130 I 9.3 I 0.3638 I 3.7 E7 E6 E -7 6 435.0 0.80 0 - 42 8.75 0.0195 0.0780 27.7 0.2330 2.4 (future) E6 E5 E -6 6 208.0 0.80 2 E -8,E -7 51 10.62 0.0237 0.0947 30.6 0.2330 2.4 E5 E4 E -5 6 125.0 0.80 4 E -6 55 11.46 0.0255 0.1021 31.8 0.2330 2..4 E4 E3 E -4 6 185.0 0.80 4 E -5,E -9 70 14.58 0.0325 0.1299 36.1 0.2330 2.4 E3 E2 E -3 6 238.0 0.80 3 E-4 73 15.21 0.0339 0.1355 36.9 0.2330 2.4 El E2 E -2 6 87.0 0.60 0 - 38 7.92 0.0176 0.0705 28.3 0.2018 2.1 (future) I E2 I E9 I E -1 1 6 I 105.0 I 0.60 I 0 I E -2,E -3 I 111 1 23.121 0.05151 0.2060 I 50.6 I 0.2018 I 2.1 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. , Q 1, ate' / 4441""A " -j 3S Design Report Proposed Sanitary Sewer Line Improvements for South Hampton Subdivision — Phase 3 College Station, Texas May 2004 Prepared By: TEXCON General Contractors 1707 Graham Road College Station, Texas 77845 (979) 764 -7743 P * JOSEPH P. S UL � . ., 65:E \ : NAL 1.0 INTRODUCTION & DESCRIPTION The purpose of this report is to provide a description of the proposed sanitary sewer to be constructed with the South Hampton Subdivision Phase 3, and to provide the criteria used in the design of this sanitary sewer system. The location of the sewer lines are shown on Exhibit A. The project will include the construction of approximately 147 feet of sanitary sewer line. The line will service the proposed development of the South Hampton Subdivision, Phase 3. 2.0 SANITARY SEWER - Design Flow and Pipe Size Calculations The proposed sewer line is to be constructed of 6" diameter SDR -26, PVC pipe which meets the requirements of ASTM- D3034. The proposed manhole is a 4' diameter manhole, and is 7' in depth, with a sewer line slope of 1.34 %. The maximum distance between manholes is less than 500 feet, as required by the Texas Commission on Environmental Quality (TCEQ). The minimum slope per the Bryan/College Station Design Guidelines is 0.8 %. The minimum allowable slope for 6" pipes per TCEQ requirements is 0.50 %. All construction shall meet the current Bryan/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 4.0 to determine the peak hourly flow. The velocities for the lines were calculated using Manning's Equation. According to the TCEQ, 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 TCEQ requirement is met. The TCEQ requires that the maximum velocity for sewer systems flowing full not exceed 10 feet per second. The values in Table 1 are well below this maximum velocity. TABLE 1 - SEWER LINE FLOW DATA Manhole No. of Units From Cumulative Average Percent 50% Full Size Length Slope Peak Flow Number Line # Dwelling Unit Merging Dwelling Daily Flow .Full Flow Velocity From To (in) (ft) ( %) Services Lines Units (gpm) (cfs) (cfs) ( %) (cfs) (fps) MI-11 E8 S -1 6 147.0 1.95 7 - 7 1.46 0.0032 0.0130 9.3 0.3638 3.7 E8 E4 E -9 6 352.0 1.34 4 S -1 11 2.29 0.0051 0.0204 12.6 0.3016 3.1 I E10 I E6 I E -8I 6 I 276.0 I 1.95 I 7 1 - 1 7 I 1.46 1 0.00321 0.0130 9.3 I 0.3638 I 3.7 E7 E6 E -7 6 435.0 0.80 0 - 42 8.75 0.0195 0.0780 27.7 0.2330 2.4 (future) E6 E5 E -6 6 208.0 0.80 2 E -8,E -7 51 10.62 0.0237 0.0947 30.6 0.2330 2.4 E5 E4 E -5 6 125.0 0.80 4 E -6 55 11.46 0.0255 0.1021 31.8 0.2330 2..4 E4 E3 E -4 6 185.0 0.80 4 E -5,E -9 70 14.58 0.0325 0.1299 36.1 0.2330 2.4 E3 E2 E -3 6 238.0 0.80 3 E -4 73 15.21 0.0339 0.1355 36.9 0.2330 2.4 E 1 E2 E -2 6 87.0 0.60 0 - 38 7.92 0.0176 0.0705 28.3 0.2018 2.1 (future) E2 I E9 I E -1 16 I 105.0 0.60 I 0 I E -2,E -3 I 111 1 23.1210.05151 0.2060 I 50.6 1 0.2018 I 2.1 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. ,