Newsletter and Technical Publications
Freshwater Management Series No. 10
Managing Urban Sewage
An Introductory Guide for Decision-makers
Sewage infrastructure construction work includes the installation of the sewage collection
system, engineering and construction of pumping stations and wastewater treatment plants,
and the installation of a wide range of machinery and electrical equipment for pumping
stations and wastewater treatment plants. Sewage infrastructure construction in urban areas
involves a number of considerations as discussed below.
A. Underground Obstacles
In most cities, underground space is highly utilized, and it is necessary to take into account
proximity to other underground facilities as subways, waterworks, electric power cables,
gas pipes and telephone lines. Special construction methods to move, reroute or undertake
work in close proximity to water and gas mains is sometimes required. Making adjustments
in consultation with those who manage underground facilities is time consuming and as a
result an extended construction period or additional costs can arise.
B. Space for Facilities and Construction Work
The construction of facilities such as treatment plants and pumping stations requires a large
amount of space. Driving shafts for base construction and for burying large sewer pipes also
requires space. Most cities use public land such as parks, or purchase or lease private land to
secure sufficient space. It is often difficult to obtain consent from land owners, and
negotiations can require a significant amount of time. Securing land can interfere with other
public works projects such as the construction or expansion of roads and the improvements
of rivers and waterways.
C. Disposal of Soil from Construction Projects
Soil generated from construction projects can be a problem and planning is necessary to
identify ways of reusing this soil or reducing the amount of soil generated.
D. Obtaining the Understanding and Cooperation of Stakeholders
Experience has shown that sewage construction projects should incorporate an ISO 14001
environmental management system. Equipment and processes should be selected to minimize
noise and vibration which can be irritants to local residents. It is also important to hold
information meetings to obtain the support of residents. This is necessary for both sewage
construction projects and the refurbishment of older sewers.