Design and Analysis of Water Supply Distribution and Sanitary Sewer System

This paper examines the design and analysis of water supply distribution and sanitary sewer system. It includes the methodology, formulas used in calculations, and iterations for the Hardy Cross method. The first section investigates the supply of water distribution, while the second section demonstrates the implementation of the sanitary sewer. The subject is relevant to civil engineering and water resource management courses.

Abstract
The paper shows and examines the design and analyzes the water supply distribution and the
design of sanitary sewer system. The first section of this report investigates the supply of water
distribution, where the problem is to adjust water distribution network by application of water
distribution network adjusting technique. Therefore, the investigation is done on the flow of
water in each and every pipe, and the process of iterations is performed on the loops, in order to
ensure that the summation of the arithmetical head loss (hf ) for any closed loop to be zero, in the
event that, the pipe flow summation should be equal the summation of flow leaving or entering
the system through each nodes. At every iteration, sensible changes happened at channels flows
until the point that the head loss has turned out to be little or settled to zero as flow-line redress,
from the design of the water distribution network for this report was found to appropriate to use
all the flow rates that were determined on the second iteration in which the summation of the
head loss was both 0.05933292 for loop A and 0.04109131 for loop B, with the flow rate of of
23.19512 l/s, 9.221238 l/s and -46.80488 l.s for loop A and for loop B, the flow rate is -9.221233
l/s, 13.07389 l/s and -37.72611 l/s, the second section demonstrate the implementation of the
sanitary sewer. It should be noted that there is anticipation on the size of the particles, the
velocity and temperature and other critical properties that may influence the water and sewer
properties.

Introduction
The piping system for the friction intensity constraint for every pipe should always be known,
and it should be free of the flow situations for the scope of flow states of intrigue. In the event
that the distribution water condition is utilized to relate head loss hL to velocity V or flow rate Q
(Spiliotis and Tsakiris, 2010), the representation of friction intensity factor is denoted by f, this
has a steady value on a specific pipe for completely turbulent flow, however it does not imply on
the transitional or laminar flow. In the event that the Hazen Williams equation (Kumar,
Narasimhan and Bhallamudi, 2010) is utilized, the friction intensity factor is CHW, which is
thought to be identified for a specific pipe.
The Hardy cross method used in analyzing the pipe network system illuminate the nonlinear
conditions associated with network investigation by making certain assumptions. The higher
power rectification terms can be dismissed and the loop number is little for a solitary loop
despite the fact that the underlying guess is weak. However, dismissing contiguous loops and
considering just a single amendment condition at once can influence the arrangement and
furthermore number of iteration required for joining increments as the measure of the system
increments.
Altered Hardy Cross strategy can be connected to enhance merging and lessen the quantity of
loops. In any case, this number can be very substantial for genuine systems. Consequently, rather
than considering just a single amendment condition at once, all the adjustment conditions can be
illuminated by thinking about the impact of every single contiguous circle. So joining can be
accomplished in fewer loops. Additionally, a portion of the conditions engaged with pipe
network investigation is nonlinear.
Problem statement
Design and analysis of pipe systems are imperative to undeveloped town or cities, not just in
light of the fact that water is an essential monetary improvement parameter, yet in addition since
water is a central factor later on of peace.

Project objectives
1. To determine pipe discharges, Q
2. To determine nodal heads, H
3. To determine pipe resistance constants, R
4. To determine nodal inflows or outflows, q
Considering a network that has different loops, at normal circumstances there will be channels
regular to bordering loops with a clockwise stream in one loop showing up as unfriendly to
clockwise in the other. Each loop must be distinguished and the rectifications made efficiently to
each loop thus. The remedy to the streams must be made each time before proceeding onward to
the following loop. For in excess of two loop in a system, the procedure turns out to be extremely
intricate and computer strategies should be utilized.

PART A
Methodology
In consideration of analyzing pipe network system, the conventionally approach is known as the
Hardy Cross procedure (Huang, Vairavamoorthy and Tsegaye, 2010). This strategy is
appropriate if the entire pipe sizes (lengths and breadths) are settled, and either the head losses
between the outlets and inlets are known yet the flow are not, or the flow at each inflow and
overflowing point are known, yet the head losses are definitely not. This last case is investigated
straightaway.
The system incorporates making a guess with respect to the flow to rate in each pipe, taking
consideration of making a guess to such an extent that the total flow into any crossing point
approaches the total flow out of that convergence. By then the head loss in each pipe is found
out, in perspective of the normal flow and the picked flow versus head loss relationship. Next,
the system is checked whether the head loss around each loop is zero. Since the fundamental
flow were speculated, this will undoubtedly not be the circumstance. The flow rates are then
adjusted with the end goal that continuity will in any case be fulfilled at each crossing point,
aside from the head loss around each loop is more similar to be zero. This strategy is repeated
until the point that the progressions are attractively little. The definite procedure is according to
the following

Procedure approach to loop
Divided the network into loops
For each loops done the fallowing steps
1. Assumptions on the flow, , flow course in the pipes, direction of flow in the loop where
positive will be taken to be clockwise or negative will be taken to be counterclockwise,
with an application of equation of continuity condition at every node. Evaluated pipe
flows are associated with iteration until head loss in the clockwise direction is equivalent
to the counterclockwise bearing in each loop.
2. The equivalent resistance K for each pipe will be required to be calculated based on the
given parameters on the demand for each node, similarly pipe length and diameter,
together with temperature and finally pipe material are expected to be unique if not it is
assumed to be equal.
3. Calculation of hf = k*𝑄n for each pipe. The sign from procedure 1 is retained and
computation is done for the sum of the loops hf
4. Computation of hf ⁄Q for each and every pipe and the summation for each and every
loop that is∑ ¿hf ⁄𝑄|.
5. Calculation of the correction by the fallowing formula ∆𝑄 = −∑ h f/( 𝑛∑ |hf ⁄𝑄 |
6. Application of correction to Qnew = Q+ΔQ
7. Repeat procedure (3) to (6) until Δh become very small.
8. Finally solving of the total pressure at each and every node using energy method

Formulas used in calculations
1.0 Continuity Formula
The sum of pipe amount of flows into and out of the respective nods equals to the amount of
flow that is entering or leaving the system through each node (Cunha and Sousa, 2010).
Hence, from the statement it means that the following equation will be resulted: QTotal = Q1 + Q2
Where,
Q = Total inflow, Q1 + Q2= Total outflow
2.0 Energy conservation formula
The total algebraic Summation of head loss hf around any closed loop is zero (Giustolisi, 2010).
Therefore, ∑ hf(loop) = 0 →∑ k ( Q+∆ Q )n=0
Where,
Q= Actual inflow,
ΔQ= Correction
K= Head loss coefficient,
n= Flow exponent.
Always the following formula should be used for general relationship between discharges and
head-losses for each pipe in loops:
hf = k*Qn
3.0 Hazen-William equation
K = 10.67
C1.85 D4.87
n = 1.87

∆ Q= −∑ h
2∗∑( h
Q )
Assume the C for all pipes = 100
(1/K)1.85 = L
[ βC D2.63 ]1.85
Where, β=278 and flow rate is in l/s and diameter is in meters
Qiteration 2loop 1=
−∑ H
n∑ H
Q
Qiteration 2loop 2=
−∑ H
n∑ H
Q
The last condition gives a way to deal with determining an estimation of ∆Q which will influence
the estimation of the head loss wherever the loop to be zero. For the underlying couple of loops,
that iteration is likely not to be correct, so the registered estimation of ∆Q won't influence the
value of head loss around the loop to be definitely zero, anyway it will influence the head loss to
be closer to zero when contrasted with the past loop. The estimation of ∆Q would then have the
capacity to be added to the main estimations of Q for each one of the pipe distribution network of
loops, and iteration can be finished. This same strategy can be used for each one of the circles in
the system. In case a pipe is a bit of no less than two particular loops, the change factors for each
one of the loop that contain it are associated with it.
As represented already, the figure gauge of the flow rates is totally optional, as long as
movement is satisfied at each convergence. On the off chance that one makes great conjectures
for these flow rates, the issue will consolidate quickly, and in case one influences poor guess, it
will take more loops for the last course of action is found. Regardless, any assessments which
meet the mass change model will finally provoke the same, and amendment will be done on the
last result.

First iteration
Lo
op
Pi
pe
Diame
ter
Leng
th
(1/
K)^1.8
5
Assu
med Q
Q^1.85 H H/Q Correcti
on
New
Q
(m) (m) (L/s) (m) (m/L/s) L/s
A ab 0.2 300 0.0045
3
30 540.35 2.44994
69
0.081664
897
-
0.53623
5
29.46
38
bc 0.2 300 0.0045
3
13.5 123.34 0.55922
356
0.041423
967
-
0.27507
998
13.22
49
cd
a
0.25 600 0.0030
6
-40 -920.05 -
2.81719
31
0.070429
828
-0.24 -
40.24
Tot
al
0.19197
736
0.193518
692
B bc 0.2 300 0.0045
3
-13.5 -123.34 -
0.55873
02
0.041387
422
0.27507
998
-
13.22
5
bef 0.2 500 0.0075
6
15.6 161.17 1.21796
169
0.078074
467
-
0.26115
502
15.33
88
cf 0.25 160 0.0008
2
-35.2 -726.28 -
0.59337
076
0.016857
124
-
0.26115
502
-
35.46
1
Tot
al
0.06586
073
0.136319
013

Second iteration
Lo
op
Pi
pe
Diame
ter
Leng
th
(1/
K)^1.85
Q Q^1.
85
H H/Q Correct
ion
New
Q
(m) (m) (L/s) (m) (m/L/s) L/s
A ab 0.2 300 0.00453 29.463
765
522.
62
2.36955
908
0.080422
821
-
3.1343
2
26.329
44
bc 0.2 300 0.00453 13.224
92
118.
73
0.53832
182
0.040705
11
-
2.0018
41
11.223
08
cd
a
0.25 600 0.00306 -
40.536
24
-
930.
29
-
2.84854
798
0.070271
646
-
3.1343
2
-
43.670
56
Tot
al
0.05933
292
0.191399
577
B bc 0.2 300 0.00453 -
13.224
92
-
118.
73
-
0.53784
69
0.040669
214
2.0018
41
-
11.223
07
bef 0.2 500 0.00756 15.338
845
156.
21
1.18047
897
0.076960
095
-
1.1324
79
14.206
37
cf 0.25 160 0.00082 -
35.461
16
-
736.
28
-
0.60154
076
0.016963
372
-
1.1324
79
-
36.593
63
Tot
al
0.04109
131
0.134592
681

Third iteration
Lo
op
Pi
pe
Diame
ter
Leng
th
(1/
K)^1.8
5
Q Q^1.85 H H/Q Correct
ion
New
Q
(m) (m) (L/s) (m) (m/L/s) L/s
A ab 0.2 300 0.0045
3
26.329
445
424.44 1.92441
096
0.073089
69
-
3.1343
2
23.19
512
bc 0.2 300 0.0045
3
11.223
079
87.64 0.39735
976
0.035405
592
-
2.0018
41
9.221
238
cd
a
0.25 600 0.0030
6
-
43.670
56
-
1068.7
6
-
3.27254
312
0.074937
062
-
3.1343
2
-
46.80
488
Tot
al
-
0.95077
24
0.183432
345
B bc 0.2 300 0.0045
3
-
11.223
07
-87.64 -
0.39700
92
0.035374
372
2.0018
41
-
9.221
233
bef 0.2 500 0.0075
6
14.206
366
135.55 1.02435
135
0.072105
094
-
1.1324
79
13.07
389
cf 0.25 160 0.0008
2
-
36.593
63
-780.37 -
0.63756
229
0.017422
765
-
1.1324
79
-
37.72
611
Tot
al
-
0.01022
014
0.124902
231

PART B
DESIGN OF SEWER LINE
Sewerage systems are designed and built to give the services of collection, diverting, treatment
and transfer of sewage and reuse of treated waste water. The design of sewerage includes design
of sewer lines that limit blockage and negligible disintegration of sewer channels sub-current of
gravity. Pumped sewerage is debilitated as the cost of pumping sewer is high. The sewer ought to
be outlined in such a way they can accomplish self-purging speed once a day with a most
extreme of 3.0m/s to maintain a strategic distance from the disintegration of sewer dividers and
channel.it ought to likewise approach openings (sewer vents) at the particular separations for
adjusting of the sewer lines on the off chance that there are blockages
A sewer system is a system of pipes used to pass on storm spillover and additionally sanitary
sewer in a city.
The design of sewer framework includes the determination of, diameter, incline slope, and invert
rises for each pipe in the framework.
Free surface flow exits for the design discharge; o that is, where the flow is by the gravitational
force; pumping stations and pressurized sewers ought not to be considered.
The sewers are of commercially accessible sizes. The design distance across should be less
economically accessible pipe having flow limit equivalent to or more noteworthy than the plan
release and fulfilling all the suitable limitations.
Sewers must be set at a profundity with the end goal that they o won't be vulnerable to ice, o will
have the capacity to deplete storm cellars, and o will have adequate padding to forestall breakage
because of ground surface stacking. o To these closures, least cover profundities must be
determined.
The sewers are joined at intersections with the end goal that the crown rise of the upstream sewer
is no lower that of the downstream sewer.
To avoid or lessen exorbitant affidavit of strong material in the sewers, a base passable stream
speed at configuration release or at scarcely full-pipe gravity stream is determined.
To anticipate scour and other unwanted impacts of high-speed stream, a greatest passable stream
speed is additionally indicated.

At any intersection or sewer vent, the downstream sewer can't be littler than any of the upstream
sewers at that intersection.
The sewer framework is a dendritic, or spreading, network converging the downstream way
without shut loop
Criteria of design of sewer line
Average sewer flow is calculated based on consumption and population
Average sewage flow Q = 0.8 * consumption
Qdesign = 2*peak factor * Q + infiltration (10%) + storm water (100% of peak flow)
Design equation using Manning`s formula (Vongvisessomjai, Tingsanchali and Babel, 2010) for
sewage flowing under gravity
V = 1
n∗¿ R2/3 * S1/2
Where,
V = velocity of flow in m/sec
R = hydraulic mean depth
S = slope of the sewer
n = coefficient of roughness for pipes (n = 0.013 for RCC pipes)
Cleansing velocity => for partially combined sewer = 0.7 m/sec
Maximum velocity used should not be greater than 2.4 m/sec, to avoid abrasion
Minimum sewer size to be used 225 mm to avoid chocking of sewer with bigger size objects
through the man hole
Minimum cover to be used = 1 m to avoid damage by live loads on sewer

Design procedure
1. Determination of present population of projected area
2. Drawing of the system layout while considering the streets and road layout.
3. Identification of the sewer line and numbering of the manhole.
4. Allocate plots to each sewer line
5. Measurement of the sewer line length as per scale of the map provided
6. Adopt the per capita sewage flow as 70% of water consumption and calculate the average
sewage flow and infiltration for all the sewer line., at this point take infiltration as 10% of
the average sewage flow
7. Calculation of peak sewage flow and design flow for the sewer lines (Hvitved-Jacobsen,
Vollertsen, and Nielsen, 2010)
8. By the usage of back calculation determine the appropriate diagram and sewer in
assumption that the sewer is fully flowing
9. In the end find the invert levels for all the sewer
10. Draw the profile for all sewer line

Data for design
Present year 2018 Design period 2038
Plots 7 10
Apartments 400 600
Flats 200 400
Assume the number of plots in the area = 280
Assume the number of apartment in the area = 3
Number of flats in the area = 3
Take the design period to be = 20 years
Present population (Pd) = 7 * 280 + 400 * 3 + 200 *3 = 3767
Annual population growth rate for Australia = 2.1%
Population density in 2038 Pd = 3767(1 + 2.1%)20 = 5709
Pd = 10*281 + 600 * 3 + 400 * 3 = 5810
Per capita water consumption = 300 lpc + 103 plc = 403 plc
Average sewer flow = pd * pcwc * 0.8/1000
= 5810 * 403 * 0.8/1000 = 1873 m3/day
= 0.0217 m3/s
Peak factor = 4

A = π∗¿(D/4)2
V = 1/N * R2/3 * S1/2
R = A/P = D/4
Q = A*V
Q=
π D2
4 ∗1
n ( D
4 )2
3∗S
1
2
Q = 0.0217 M3/S
S =0.001
N = 0.015
0.0217=
π D2
4 ∗1
0.015 ( D
4 ) 2
3∗0.001
1
2
D8/5 = 0.033022
D = 0.004267 M
D = 0.4 (TAKE)
V = Q/A
V = 0.0217/A
V = 1517 M/S which is greater than 0.6 m/s
Determination of manhole distance and pipe slope
Procedure

1. Demonstrate the inverted height on profile for each pipe entering and leaving the sewer manhole at
within sewer manhole wall.
2. Since the design sewer pipe has a diameter of 0.004m and is less than 1.2 m then the following will be
considered, the distance between center to center is 100 m
a) The pipe distance will be determined by subtracting one half inside the dimension of on which the
sewer manhole, for both manhole from the total distance between the centerline of both manholes.
In the event that we take the two sewer manhole are having a most extreme of 2.0 m measurement, at
that point the aggregate separation distance between the two sewer manhole with respect to centerline
to centerline is 100m, and the separation distance between the centerline of the sewer manhole to the
inside wall of the sewer manhole is 1.0 m.
Since the two sewer manhole are a similar width, subtract 2.0 m from the aggregate separation distance
100 – 2= 98 m, the pipe remove between sewer manhole will be 98 m however a separation distance of
100 m ought to be appeared on the profile.
b) To decide the pipe slope, subtract the two sewer manhole inverts and divide the difference by the
pipe distance and multiply by one hundred (100) to acquire the percent review of the pipe.
If the manhole invert elevations are 52.5 m as per the contours for one manhole and 50 for the other,
then the difference between the two manhole inverts will be 2.5.00 m
Take the invert difference 5 .00 m and divide it by the pipe distance (98 m). The pipe slope will be 0.025
m per hundred meters or 2.5%. Show the pipe slope on the profile.
Table having assumption of values
Fro
m
man
hole
To
man
hole
Le
ngt
h
Area
incre
ment
Coeff
icient
C
Red
uctio
n in
Area
Cum
ulativ
e
reduc
tion
in
area
Rai
nfal
l
inte
nsit
y
Q Gro
und
surf
ace
upp
er
end
Lo
wer
end
inv
ert
upp
er
end
low
er
end
slo
pe
of
se
wer
(%)
1 2 100 1.5 0.7 1.05 1.05 <10 227
5.5
10 9.8 8.6 8.3 2.5
2 3 100 1 0.7 0.7 1.75 <10 151 9.8 9 8.4 7.5 8.5

7
3 4 100 0.9 0.7 0.63 2.38 10 136
5.3
9 9 7.4 7.2 1.7
Tot
al
300
4 5 100 0.6 0.9 0.54 0.54 12 910
.2
9 9.2 7 6.9 2.5
5 6 100 0.8 0.9 0.72 1.26 12 121
3.6
9.2 9 6.8 6.7 3.2
6 13 50 0.4 0.4 0.16 1.42 13 606
.8
9 9 6.2 6.1 1.3
Tot
al
250
7 8 100 1.5 0.4 0.6 0.6 <10 227
5.5
9.3 9.1 7.9 7.7 3.3
8 4 100 0.8 0.7 0.56 1.16 <10 121
3.6
9.1 9 7.7 7.3 2
9 10 100 1.5 0.4 0.6 1.76 <10 227
5.5
9.2 8.8 7.9 7.6 1.1
Tot
al
300
10 5 100 0.9 0.9 0.81 0.81 <10 136
5.3
8.8 9.2 7.4 7.2 4
11 12 100 1.5 0.1 0.15 0.96 <10 227
5.5
9.8 8.7 7.6 7.2 3.3
12 6 100 0.8 0.4 0.32 1.28 <10 121
3.6
8.7 9 7.1 6.8 1.4
Tot
al
300
SKETCH OF A PORTION OF SANITARY SEWER LINE PROFILE
1ST MANHOLE 2ND MANHOLE
PIPE SIZE = 0.004 M
2.5 SLOPE = 2.5% SIZE OF THE MAN HOLE EXTREEMS = 2.0

98 M
100 M
ELEVATION DIFFERENCE = 60 = 55 = 5

Conclusion
The pipe discharges, Q was determined from the use of Hardy cross method when the value of
head loss tend to be zero, as 23.19512 l/s, 9.221238 l/s and -46.80488 l.s for loop A and for loop
B, the flow rate is -9.221233 l/s, 13.07389 l/s and -37.72611 l/s.
The head loss at every nodal was determine from the first iteration and second iteration and the
summation of head loss was both 0.05933292 for loop A and 0.04109131 for loop B.

References
Cunha, M.D.C. and Sousa, J.J.D.O., 2010. Robust design of water distribution networks for a
proactive risk management. Journal of Water Resources Planning and Management, 136(2),
pp.227-236.
Giustolisi, O., 2010. Considering actual pipe connections in water distribution network
analysis. Journal of Hydraulic Engineering, 136(11), pp.889-900.
Huang, D., Vairavamoorthy, K. and Tsegaye, S., 2010. Flexible design of urban water
distribution networks. In World Environmental and Water Resources Congress 2010: Challenges
of Change (pp. 4225-4236).
Hvitved-Jacobsen, T., Vollertsen, J. and Nielsen, A.H., 2010. Urban and highway stormwater
pollution: Concepts and engineering. CRC press..
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distribution networks. Water resources management, 24(6), pp.1251-1272.
Spiliotis, M. and Tsakiris, G., 2010. Water distribution system analysis: Newton-Raphson
method revisited. Journal of Hydraulic Engineering, 137(8), pp.852-855.
Vongvisessomjai, N., Tingsanchali, T. and Babel, M.S., 2010. Non-deposition design criteria for
sewers with part-full flow. Urban Water Journal, 7(1), pp.61-77.