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.
,
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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.
,