Skip to main content
Feb 26, 2016 / Haseeb Jamal -

5 Travel Myths You Need to Stop Believing Right Now

Feb 26, 2016 / Haseeb Jamal -

Canal Comes Alive with Lighted Boat Parade.

Sanitary Sewer Design Example # 1

By: Syed Ahmad Amin Shah / On: Feb 05, 2019 / Design of, Sewers

Problem Statement

Design a sanitary sewer to serve a population of 5,000 people, if the average consumption is 400 liters per capita per day (lpcd). How many extra persons can be served if the slope is doubled? Using "n" value of 0.013 in the Manning's formula & the return flow as 70%. Check the minimum self-cleaning velocity. Neglect infiltration & inflow?

Given Data:  

Population (P)

= 5000 Persons

Average water consumption (q)

= 400 lpcd

Manning Coefficient (n)

= 0.013

Return Flow

= 70 %

Assume Slop (s)

= 0.005

1. Find the Velocity (V) =? Also check minimum self cleaning velocity

2. When the slope is doubled find the extra population to be served =?



Average waste water flow (qw)

= P * Return flow (%) * q
  = 5000 * 0.7 * 400  
  = 1,400,000 lpcd  
  = 0.0162 m3/sec  

Let take peaking factor (P.F)

= 3  

Peak Hourly Waste Water Flow

= 3 * 0.0162  
  = 0.0486 m3/sec  

Now finding the diameter of sewer pipe line

Using discharge formula;


Q = AV


0.0162 = (\frac{\Pi }{4} D2) (\frac{1}{n} R2/3 S1/2)

D = 0.264 m (264mm or 10.40”)

Use 12” Dia pipe

Checking the minimum self cleaning velocity

V = ( \frac{1}{n}R2/3 S1/2) Where R = (D/4)2/3 -------- for circular pipe

V = 0.96 m/sec

Vmin = 0.6 m/sec < V = 0.96 m/sec < Vmax = 2.5 m/sec


Doubling the slope i.e. 2 S = 0.01

Q = (\frac{\Pi }{4} D2) ( \frac{1}{n} R2/3 S1/2)

Q = 0.0331 (m3/s)

Q = P * qw

P = Q/qw Where qw = Return flow (%) * q (= 280 lpcd )

P = \frac{2,860,429.78}{280} \frac{(Liters/Day)}{(Liters/Capita/Day)}

P = 10,216 Persons

So, if the slop is doubled then total of 10,216 extra persons can be served.


preyasi Jun 27, 2019

Nice blog, the article you have shared is good.This article is very useful. My friend suggest me to use this blog.
mba college in chandigarh
cgc placement

preyasi Jul 09, 2019

Our academic pursuits, along with a range of extracurricular activities, help in honing a child's skills and ensuring that he/she grows to be a mature and responsible citizen.
best school in greater noida

Merrie Jul 15, 2019
Merrie Jul 15, 2019

This example is better than all the other examples that you've shared with us on this website. I wish you can tell us about the reviews website now. I would appreciate that more than anything in the world.

ShirleyMann Jul 21, 2019

This sewer design is unique, and I like it a lot. Can you show us a design where you focus on the main aspects of real money pokies game in New Zealand? I have asked some friends here in New Zealand to do this, but they haven't replied to me yet.

preyasi Jul 24, 2019

We are known for our quality of support and customer service. This high quality support is delivered through our regional and branch offices across the country.
apple authorized service center in kolkata
macbook pro reseller in mumbai
apple reseller in Kolkata

fredluis21 Aug 23, 2019

I really like your article.  It’s evident that you have a lot knowledge on this topic.  Your points are well made and relatable.Thanks for writing engaging and interesting material. tree service

Subscribe to our Newsletter

Stay informed - subscribe to our newsletter.
The subscriber's email address.

Search AboutCivil

Related Civil-Engg. Content