Water Treatment Technologies and Their Costs - Global Drinking Water Management and Conservation - page 32

by 63 percent of respondents, whereas those who used chloramine accounted for
30 percent; chlorine dioxide for 8 percent; ozone for 9 percent; and ultraviolet light
(UV) for 2 percent. The comparable

figures for Canada are also available: according
to the Environment Canada survey of Municipal Water and Wastewater Plants
(2004), in Canada there were 2,402 drinking water systems in that survey, of which
1,513 reported a population of fewer than 3,000. Of these 1,513 drinking water
plants, 136 gave information on the type of disinfection technology they use. Some
93 per cent (127 out of 136) used chlorine as the only disinfectant. Those using UV
or ozonation accounted for only 6 percent of the total. There is a potential for
improving water quality by adopting newer technologies such as UV or ozonation
and reducing the probability of waterborne disease outbreaks. At the same time,
there is an enormous market potential for corporations that can sell a competitive
technology that is also cost-effective. The rest of the chapter presents average “ rst

approximation cost per cubic meter based on statistical modeling on recently

collected data on costs for different

”

flow rates from equipment manufacturers in
North America. We show that there exists a menu of cost-effective technologies that
might be considered for possible modernization of water treatment plants, including
small water treatment plants.
We classify these technologies into six classes, depending on the contaminants
removed. Our statistical results show that average costs (including capital, oper-
ating, and maintenance) of production of these technologies depend on the flow rate
as well as the number of contaminants removed. The larger the

flow rate is, the
lower the cost will be per unit of volume treated, and the more the contaminants
removed are, the higher will be the cost, for any given flow rate. One of our major

findings is that for surface waters except those with high color and turbidity, UV-
based treatment technologies are cost-effective. However, for any particular system,
water engineers would take site-speci

c features into account to determine what

technology is most appropriate.
This chapter is organized as follows. Section 3.2 of this chapter presents a
scheme, which classi es water treatment technologies based on the contaminants

they remove; Sect. 3.3 shows projected costs of four technologies, which are Ultra
Violet disinfection (UV), Micro

ltration — ultra filtration (MF-UF), High rate

Clari cation & Filtration (HRC), and Ozonation; Sect. 3.4 is an analysis of the costs

of Advanced Oxidation Processes; Sect. 3.5 makes brief reference to Reverse-
Osmosis (RO) and Nano-Filtration (NF), but there is a whole chapter devoted to RO
and other more advanced treatment technologies (Chap. 4 ) . In Sect. 3.6 , we present
examples of costs of actual existing small water treatment systems in Canada.
Finally, Sect. 3.7 is a general summary with concluding remarks. Our major con-
clusion is that for surface water sources except those sources with high color and/or
high turbidity, UV is a competitive and viable treatment technology that should be
considered in a menu of suitable technologies. However, as stated before, the actual
adoption of a treatment technology depends on many site-speci

c features (such as
location, distance from major cities, and topography) that are best determined by
the consulting engineers.