HomeMy WebLinkAboutSanitary Sewero (4 -- t 43
Sanitary Sewer Master Plan
for
Williams Creek Subdivision
College Station, Texas
July 2004
Prepared By:
TEXCON General Contractors
1707 Graham Road
College Station, Texas 77845
(979) 764 -7743
7 -2 -0l'
1.0
2.0
INTRODUCTION & DESCRIPTION
The Williams Creek Subdivision is a proposed rural residential subdivision located east of
Rock Prairie Road and south of Greens Prairie Road in College Station, Texas. Sanitary
sewer service is not available to serve this subdivision, so each of the lots will be 1.0 acre or
greater in size and have On -Site Sewage Facilities (OSSF). These OSSF's will be designed
and constructed in accordance with all TCEQ and Brazos County Health Department
requirements.
SANITARY SEWER DESIGN CRITERIA
The sanitary sewer system plan was designed in accordance with the requirements of the
Bryan/College Station Design Guidelines and the TCEQ. All lines will meet all applicable
city, state, and federal regulations. The minimum finish floor elevations shown on the plan
are 4 feet greater than the flow line elevation of the sanitary sewer main which serves the
residential lot. Due to the steep topography found in portions of the subdivision, the
sanitary sewer lines must be located in the rear portion of lots in order for gravity sewer
service. This plan also assumes that an 8" diameter sewer line would be constructed by the
City of College Station along Greens Prairie Road from Lick Creek to Rock Prairie Road as
shown on the 2002 Area 5 Annexation Plan.
3.0 SANITARY SEWER MASTER PLAN
The sanitary sewer system presented in this master plan is shown on Exhibit A. The
location of all manholes, gravity flow lines, lift stations and force mains are shown on this
Exhibit. Also, it was assumed that the existing streams crossed by the sewer lines would be
bored and cased due to COE permitting requirements. The location of these casing pipes is
also shown on Exhibit A.
The proposed Williams Creek Subdivision has 111 residential lots. All of these lots would
have gravity sanitary sewer service if the structures are constructed with the minimum finish
floor elevations shown on Exhibit A and if the sanitary sewer facilities shown on this plan
were constructed. All of the sewer lines within the subdivision are gravity flow. These
lines discharge into Lift Station No. 2, which would lift the flow approximately 15 feet in
elevation and discharge it into gravity lines that drain to Lift Station No. 1 located adjacent
to Greens Prairie Road. Lift Station No. 1 lifts the flow and discharges into a 4 -inch
diameter force main, which conveys the flow to Manhole No. 60. Lift Station No. 1 and the
force main lift the flow approximately 55 feet in elevation. The flow would then gravity
flow to the existing sanitary sewer line near Lick Creek.
Table 1 is a summary of the design characteristics for each of the sanitary sewer manholes
and lines. Table 2 shows the capacity of sanitary sewer line segment 560, which is an 8-
inch diameter line at 0.4% slope. At its capacity, this line could serve 450 residential
dwelling emits, so this line can serve not only the proposed 111 lots in the Williams Creek
Subdivision, but also some of the surrounding area.
The sanitary sewer system consists of the following
Lift Stations
2 each
Manholes
61 each
6" Pipe
5,638 linear feet
8" Pipe
13,612 linear fect
4" Force Main
1,659 linear feel
4.0 CONCLUSIONS
This Sanitary Sewer Master Plan complies with Section 12 -R.2 of the Rural Residential
Subdivision Regulations, except that plan and profile layouts of the sewer system are not
provided. A variance was approved by the Planning and Zoning Commission on June 17,
2004, that eliminated the requirement that plan and profile layouts be provided with this
Master Plan.
TABLE 1
Sanitary Sewer Summary
SANITARY SEWER
SEGMENT
PIPE
PIPE
LIFT STATION/
MH
MH
MANHOLE RIM
SEGMENT No.
LENGTH
DIAMETER
SLOPE
MH No.
FLOUT
FL IN
ELEVATION
(ft)
(in)
M
(ft)
(ft)
(ft)
S -1
428
8
0.40
1
-
203.65
218.3
S -2
358
8
0.40
3
205.36
205.46
218.3
S -3
255
8
0.40
4
206.87
206.97
214.4
S -4
353
8
0.94
5
207.98
208.08
212.3
2
211.38
196.00
215.7
S -5
453
8
0.40
2
211.38
196.00
215.6
S -6
383
8
0.40
6
197.80
197.90
218.7
S -7
235
8
0.40
7
199.42
199.52
214.8
S -8
499
8
0.40
8
200.50
200.55
216.3
S -9
450
8
0.40
9
202.53
202.63
213.3
S -10
450
8
0.40
10
204.41
204.51
210.8
S -11
387
8
0.40
11
206.29
206.39
210.3
S -12
452
8
0.40
12
207.92
208.02
212.5
S -13
453
8
0.40
13
209.81
209.91
216.7
S -14
378
8
2.73
14
211.71
213.71
225.5
S -15
323
8
3.20
15
223.91
224.01
231.3
S -16
173
8
0.40
16
234.22
234.32
243.7
S -17
270
8
3.34
17
235.00
235.10
244.0
S -18
248
8
2.19
18
244.00
247.42
254.7
S -19
276
8
2.20
19
252.77
252.87
263.5
S -20
268
8
0.40
20
258.85
258.95
267.9
S -21
250
8
0.40
21
260.00
260.10
268.6
S -22
500
8
0.89
22
261.08
261.18
268.4
S -23
497
8
0.40
23
265.59
265.69
274.0
S -24
498
8
0.40
24
267.66
267.76
281.2
S -25
371
8
0.40
25
269.74
269.84
282.0
S -26
251
8
0.40
26
271.31
271.41
280.8
27
272.40
279.2
S -27
223
8
3.14
6
197.80
211.44
218.8
S -28
416
8
0.40
28
218.31
218.41
234.6
S -29
364
8
0.40
29
220.06
220.16
230.9
S -30
215
8
3.06
30
221.60
226.44
234.2
S -31
291
8
1.55
31
232.89
232.99
240.3
S -32
330
6
4.95
32
237.45
247.21
254.6
S -33
176
6
4.52
33
263.32
263.42
270.7
S -34
309
6
0.80
34
271.21
271.31
278.6
35
273.76
280.9
S -35
152
8
0.40
30
221.60
221.70
233.2
S -36
294
8
0.40
36
224.79
228.49
236.5
S -37
303
8
0.40
37
229.69
229.79
244.6
S -38
165
8
0.40
38
230.95
231.92
242.9
S -39
166
6
0.80
39
232.56
232.66
243.5
40
233.95
233.95
243.2
TABLE 1, continued
Sanitary Sewer Summary
SANITARY SEWER
SEGMENT
PIPE
PIPE
LIFT STATION/
MH
MH
MANHOLE RIM
SEGMENT No.
LENGTH
DIAMETER
SLOPE
MH No.
FLOUT
FL IN
ELEVATION
(ft)
(in)
M
(ft)
(ft)
(ft)
S -40
384
8
0.40
32
237.45
237.55
254.4
S -41
338
8
0.40
41
239.07
239.17
249.6
42
240.51
240.51
247.3
S -42
410
6
1.65
7
199.42
207.53
214.8
S -43
344
6
1.89
43
214.25
216.05
222.7
44
222.46
222.46
230.3
S -44
369
6
2.91
8
200.50
209.62
216.5
S -45
450
6
0.80
45
220.24
220.34
235.4
S -46
282
6
0.80
46
223.90
224.00
236.9
S -47
375
6
0.80
47
226.23
226.33
235.0
S -48
278
6
0.80
48
229.30
231.20
237.6
S -49
270
6
0.80
49
233.39
233.49
250.5
S -50
310
6
5.32
50
235.62
235.72
242.4
51
252.00
252.00
263.2
S -51
223
6
5.52
16
234.22
235.11
243.8
S -52
238
6
5.67
52
247.20
247.30
254.7
S -53
112
6
2.15
53
260.58
260.68
268.1
54
263.00
263.00
270.3
S -54
233
6
1.07
20
258.85
260.44
267.9
55
262.90
262.90
270.2
S -55
142
6
0.80
36
224.79
224.89
236.4
56
226.00
226.00
230.3
S -56
125
6
0.80
37
229.69
231.03
244.6
57
232.00
232.00
236.4
S -57
123
6
0.80
38
230.95
231.05
242.8
58
232.00
232.00
236.3
S -58
373
6
6.32
39
232.56
236.21
243.5
59
259.51
259.51
264.0
S -59
376
8
0.91
63
251.00
251.10
260.8
S -60
435
8
0.40
62
251.87
251.97
259.5
S -61
196
8
0.40
61
253.70
255.60
263.0
60
259.00
259.10
266.3
S -62
1659
4`
FORCE MAIN
TABLE 2
Peak Flow Determination
Land -Use Method — Residential — 2.67 persons per unit
Average Flow = 100 gpd /cap
Peak Flow = (Average Flow) * 4
Peak Flow per unit =
2.67 cap /D.U. * 100 gpd = 267 gpd * 4 = 1,068 gpd
= 0.74 gpm = 0.0017 cfs per unit
8" diameter pipe, slope = 0.4 %, n = 0.013
Full Flow Rate = 0.7643 cfs
(0.7643 cfs / 0.0017 cfs /unit) = 450 units