Environmental Engineering Reference
In-Depth Information
limited. Surface water and groundwater supply systems may be comprised
of canals, pipes, and other conveyances; pumping plants; distribution reser-
voirs or tanks to assist in balancing supplies and demands for water and to
control pressures; other appurtenances; and treatment works.
Note:
To illustrate the process of drinking water supply conveyance and
distribution in its most basic form, we concentrate here on the major com-
ponents of a typical surface water supply and distribution system.
In a typical community water supply system, water is transported under
pressure through a distribution network of buried pipes. Smaller pipes
(house service lines) attached to the main water lines bring water from the
distribution network to households. In many community water supply sys-
tems, pumping water up into storage tanks that store water at higher ele-
vations than the households they serve provides water pressure. The force
of gravity then pushes the water into homes when household taps open.
Households on private supplies usually get their water from private wells.
A pump brings the water out of the ground and into a small tank within the
home, where the water is stored under pressure.
In cities, the distribution system generally follows street patterns, but it
is also affected by topography and by the types of residential, commercial,
and industrial development, as well as the location of treatment facilities and
storage works. A distribution system is often divided into zones that corre-
spond to different ground elevations and service pressures. The water pipes
(mains) are generally enclosed loops, so supply to any point can be provided
from at least two directions. Street mains usually have a minimum diameter
of 6 to 8 inches to provide adequate flows for buildings and for fighting fires.
The pipes connected to buildings may range down in size to as little as 1 inch
for small residences.
Community Users
Pump
WWTP
Outfall
Figure 5.4
Example of groundwater supply system.
