Abstract

Although a number of jurisdictions in Europe have abandoned chlorine as a disinfectant, most water utilities with conventional water treatment plants in North America seem to rely on chlorine for disinfection. However there are a number of newer treatment technologies that offer advantages and appear to be cost effective at a number of scales. It is the objective of this paper to consider 5 newer treatment technologies and work out the cost differentials as a function of scale. We use nonlinear least squares regression to estimate the average unit cost in US dollars as a function of scale and demonstrate the extent to which these technologies differ in cost. We show that at a certain scale the differentials narrow and project the switch point at which some of the technology costs cross over, indicating the flow rates at which some technologies become cost effective.

Key words: Drinking water treatment technologies, costs of treatment, small water systems, disinfection, economies of scale, ultra violet (UV), ozonation.