Contents

Introduction

- Sewers will be designed to discharge the wastewater

flows as required. Generally, it is not desirable to design sewers for full flow, even at peak rates .

- There is some information we need to know about the location before we start designing the pipe network :

- Maps .- Contour maps ( elevations ) .- Road network .- Area population .- Coordinates .- The purpose of building .

-Objective:

The aim of this project is to design a sewer network for a nearly 2500 m squared area , and transfer wastewater to an area 5 km away from the

first area.

- Programs Used :1- AutoCad 2- Excel

Project description :

Area Classification :

Location : Al salam at Al Madena Al-Monawara , Suidia Arabia .Purpose : ResidentialDimensions : 680 m X 600 m .Number of buildings : 78 buildings .

Top view :

The 5 km away location:

Flow Estimation :

- Each person generates 75 L/d of wastewater .- Peak flow is between 7:00 to 7:30 o’clock .- Assume at that time each person generates 30 L ( for shower ,

bathroom , .. etc ) .- Each building have nearly 10 floors ( high buildings ) and each floor

contains about 15 persons .- So Q = 0.03 * 10 *15/1800 = 0.003 .

Procedure & Work

After Choosing a location 1- Choose a suitable place for manholes :- each building have it’s own manhole . - spacing between manholes should not exceed the maximum spacing which found based on diameter .

2-Find Surface Elevations :

- In this project elevations have been founded using www.freeaptools.com/elevation-finder.htm

- Surface elevations of buildings is estimated that it’s the road elevation plus sidewalk height ( 20 cm ) .

3- Choose A suitable pipe diameters :In this project , pipe diameter choosen as the following :Home Connections = 200 mm ( H to S or H to M)Main = 300 – 400 mm ( S to S or S to M )Trunks = 500 mm ( M to M )15 km pipes = 800 mm ( MH to MH )

4- Find pipe lengths : The is two way to find the pipe lengths first one using the following website :http://veloroutes.org/bikemaps/ second way : by drawing A-Cad scale Layout Note : Layout for this project At page

5- Compute Grade of Surface & Choose a suitable Grade for sewer .- Grade of sewer must be large than minimum slope which based on

pipe diameter .

6- Compute Vfull , Qfull , Q/Qfull

Vfull = (1/n)*R^(2/3)*S^0.5

Qfull = Vfull*Area

7- Find V/Vfull .

To find V/ Vull , find the regression between Q/Qfull & V/Vfull as the following :

8- Find Velocity & Check velocity.- V= (v/Vfull) * Vfull - Velocity Must be larger than 0.6 and smaller than 3.0 .

9- Fing fall of sewer Fall = slope of sewer * length

10-Estimate the first upper manhole invert level .

- In this project is equal to surface elevation – 1.2 m because of home connections .

11-Find the lower mahole invert level .

- Lower invert = upper – fall

12 Find Depth of lower .

- Depth should be less than 7 m ( for economical reasons ) .

Notes : - Start your design with main street manholes , then trunk manholes ,

then 5 km length , finishing with home connections .- All previous calculations are in the results using excel sheet .

Layout :

Area layout :

- 5 km Layout :

Home Connections Layout :

Results :

Calculations

- Profiles : Trunk Profiles

Main profiles :

5 km Profile :

Home Connections :

References :

- Waste & Wastewater Engineering , Mackenize L.Davis .- Google Maps - http://veloroutes.org/bikemaps/ - Elevation Finder