Water Treatment Technologies and Their Costs - Global Drinking Water Management and Conservation - page 31

Chapter 3
Water Treatment Technologies
and Their Costs

3.1 Introduction

According to the USEPA (1996), 94 percent of 156,000 public water systems in the
US are small water systems, serving a population of fewer than 3,300 people. In
Canada, the proportion of small systems in one survey was over 75 percent (Envi-
ronment Canada 2004). With a smaller tax base all small water systems face special
challenges, unless the government aggressively supports small water treatment
systems. In Canada, many continue to encounter boil water advisories and even
disease outbreaks. No doubt that with appropriate public funding, many of these
problems can be reduced or eliminated. However, typically in North America, each
small community or rural jurisdiction must cover its own capital and operating costs
of their drinking water supply, although some jurisdictions offer a subsidy for capital
costs. Often a rural community has a small population, lower average income, and
consequently a lower tax base. These financial constraints as well as other risk

factors were highlighted at a 2004 Montana conference on small water systems (Ford
et al. 2004 ). These constraints are even more severe in developing countries.
Threats to public health persist in rural and small water systems even in the most
advanced high-income countries like the USA, Canada, and Europe. The factors
accounting for some of these waterborne disease outbreaks were explored in
Chap. 2 . The objective of this chapter is to present statistical models of costs based
on new data obtained from manufacturers of a menu of treatment technologies
suitable for water systems, small and large; this information would be of use to local
government of

cials, water engineers, and planners. Most of these technologies are
concerned mainly with plants that rely on surface water as the source.
For the USA, the American Water and Wastewater Association (AWWA) has
published a number of reports that include recent water utility survey data on
current disinfection practices and operations compared with practices in the late
1970s (AWWA Water Quality Division Disinfection 1992 and 2008 ). According to
the AWWA 2008 report, chlorine gas remained the predominant disinfectant, used