Risk, Drinking Water and Harmful Algal Blooms: A Contingent Valuation of Water Bans

Facilities using surface water to provide drinking water to communities must contend with the risk of cyanobacteria and cyanotoxin infiltration. Although risk management protocols can be put in place to anticipate the presence of cyanotoxins in concentrations exceeding guidelines, based on cyanobacterial cell count for example, this indicator is not infallible. The Canadian province of Quebec, among other jurisdictions, issues water bans when high concentrations of cyanotoxins are detected. While necessary, these bans are costly to communities. We perform a contingent valuation survey in areas at risk of being impacted by a water ban in the future to assess the preferences of residents and the economic value of detection and treatment tools that could eliminate cyanotoxins. The survey was completed by 240 people. Each respondent was asked a double-bounded dichotomous choice question. The scenario implied changes to the current situation regarding the possibility of predicting the presence of cyanotoxins in the facility, the average duration of water bans, the possibility of providing advance notice, all relative to the cost of these measures. The analysis of the survey responses allowed us to determine the willingness to pay (WTP) of households for diagnostic and treatment tools in drinking water facilities. Our analysis indicates that the mean WTP was $135 per household per year. Given that the experts developing the tools estimate the cost of implementation at $110 per household per year, our results suggest that implementation is economically viable.