TO TREAT OR NOT TO TREAT: COMMUNICATING THE HEALTH RISK POSED BY DRINKING UNTREATED GROUNDWATER

Recent research on the fate and transport of human enteric viruses in groundwater indicates that disinfection of municipal groundwater supplies has a public health benefit. The U.S. EPA established a risk-based approach to pathogen safety at systems supplied with groundwater; federal regulations mandate continuous disinfection at public water systems that rely on surface water but not at groundwater-sourced systems. Following the release of reports documenting pathogen contamination in water-supply wells, Wisconsin regulators established a requirement for continuous disinfection at groundwater-sourced systems, but the state legislature subsequently rescinded this rule.

Why did many legislators and their constituents oppose what seemed to be a requirement intended to improve public health? This question motivated a study to investigate apparent differences in stakeholder perceptions of water quality. Interviews conducted with 33 water system managers, state and federal regulators, public health officials, and water supply engineers revealed several impediments to improving the pathogen safety of groundwater supplies. Stakeholders varied widely in their knowledge and acceptance of relevant, recent research, as well as their understanding of the total coliform bacteria test, which is currently required by the Groundwater Rule. Some stakeholders expressed concern about the capacity of small water systems to address water quality changes associated with chlorination of groundwater, such as changes in odor, taste, and iron precipitation.

The groundwater disinfection controversy in Wisconsin illustrates challenges associated with implementing policies based on highly specific and technical research findings. This study revealed institutional arrangements that limited communication of research to those tasked with governing and operating groundwater systems in small towns and villages. The Wisconsin experience with groundwater disinfection illustrates how advances in characterizing water quality can outpace society’s ability to act on these findings. Communicating research results is one of several elements necessary to implement science-based changes in the regulation of public water supplies.