In June 2022, Wisconsin lawmakers approved a new drinking water standard for two of the most widely used per- and polyfluoroalkyl substances (PFAS). Prized for their water and stain-resistant properties, PFAS are found in an array of industry and consumer products, including firefighting foam, cosmetics, waterproof fabrics, nonstick cookware, and food containers. These human-made compounds are commonly referred to as “forever chemicals.” Resistant to chemical breakdown, they persist and accumulate in our bodies and environment. A growing body of scientific evidence links these chemicals to increased risk of certain cancers, high blood pressure, low birth rate, developmental delays, and harm to immune and reproductive systems.

Wisconsin’s latest regulatory action follows years of state and national debate about the risks of PFAS. The new drinking water standard sets the limit at 70 parts per trillion (ppt) for PFOA and PFOS, in line with a 2016 Health Advisory Level (HAL) issued by the US Environmental Protection Agency (EPA), but higher than the level recommended (20 ppt) by the state’s Department of Health Services and scientists working on the regulation.

There are currently no federal regulations for PFAS. However, just two days after the state legislature approved the standard, the EPA issued a new health advisory, reducing its previous recommended HALs to .004 ppt (PFOA) and .02 ppt (PFOS) in response to emerging evidence that even levels closer to zero are associated with adverse health effects. Because we currently don’t have the ability to detect PFAS at such low levels, any detectable amount would exceed those thresholds. The EPA is expected to issue a proposed National Primary Drinking Water Regulation for PFOA and PFOS later this year.

Wisconsin’s new drinking water standard requires that communities test public water systems for PFOA and PFOS. Those water systems that exceed the limit (for either of the chemicals or a combination of the two) will have to take corrective action. Public water utilities are also now required to issue a public notice for any amount over 20 ppt and disclose PFAS levels in their annual consumer confidence reports.

Voluntary tests of private wells conducted by the Department of Natural Resources (DNR) and others show that PFAS contamination is not just a concern for public water utilities. Wisconsin’s new standard, however, does not apply to groundwater. Nearly 30 percent of Wisconsin residents rely on private groundwater wells that are not connected to a public water system for their drinking water. Amidst growing concern about the risks of PFAS, the Natural Resources Board voted this past December to allow the DNR to move forward with developing separate standards for PFAS in groundwater.

Public understanding of PFAS risk and contamination will likely change as testing gets underway and more residents become aware of possible exposure. How concerned are Wisconsin residents about PFAS? Last June, we partnered with the Marquette Law School Poll (MLSP) to survey Wisconsin residents about their perceptions of PFAS risk and water quality in their communities. The survey was fielded just one week after the state legislature approved the drinking water standard and the EPA released its new health advisory. Wisconsin’s PFAS regulation took effect on August 1.

We found that many Wisconsin residents are worried about PFAS. Roughly 6 out of 10 respondents expressed some level of concern about PFAS contamination in their drinking water. Nearly twice as many said they were “very concerned” (31 percent) than said they were “not at all concerned” (18 percent). Five percent said they didn’t know.

We might expect some geographic variation in concern given differences in communities’ experiences. The city of Eau Claire, for example, shut down half of its wells because of PFAS contamination in 2021. There have been several other high-profile cases of PFAS contamination in the state, including in Madison and the Peshtigo and Marinette areas (Green Bay-Appleton media market). The Department of Natural Resources (DNR) lists over 120 sites with known PFAS contamination. Although there is some variation across Wisconsin’s media markets, none of the regional differences are statistically significant.

Several individual-level differences, however, are worth noting. Those getting their drinking water from public water systems expressed more concern about PFAS and the safety of their water supply than those on private wells. Consistent with previous research on gendered differences in risk perception, women expressed greater concern than men, all else equal. Wisconsin residents who reported paying attention to politics, whether there’s an election going on or not, were also more worried than those who reported paying little or no attention. And finally, we observe a partisan divide: Democrats and Independents expressed slightly more concern about PFAS than Republicans, all else equal. That said, we don’t want to overstate the difference: majorities of both Republicans (55%) and Democrats (72%) expressed concern.

We also asked respondents about their perceptions of safety of the drinking water supply in their community, a question that the MLSP has asked several times over the last few years. Because question wording was unchanged, we can compare responses over time. Concern in the state, on average, remains relatively flat, with roughly 4 out of 10 respondents saying they are “concerned” or “very concerned” about the safety of their water supply. There is a notable uptick in 2018, which is explained by increased concern in the WOW counties and Milwaukee County. There were several water-related issues in the news in this part of the state at the time, including the city of Waukesha’s approved plan to divert Lake Michigan water for public water supply (under an amended court order to comply with radium standards) and debates about how the city of Milwaukee was handling lead in drinking water. It’s possible that the rise in concern in 2018 reflected this high-profile news about water quality.

In our June 2022 poll, we found that Democrats were more concerned about PFAS than Republicans. Looking back at previous polls, however, we find that the partisan divide on water is recent and remains modest. In 2016 and 2018, the average opinions of Democrats and Republicans were statistically indistinguishable from one another. The partisan gap widens a bit in 2019, but the difference is not statistically significant. The figure below shows the unadjusted differences in opinion between Democrats and Republicans. Although the partisan gap is statistically significant in the June 2022 poll, it is substantively small, just four percentage points once we account for other factors, including socioeconomic status and whether the respondent lives in an urban, suburban, or rural community.      

Previous research finds that framing—how an issue or problem is presented—can affect risk perceptions. We included a survey experiment to test whether geographic frames of reference affect Wisconsin residents’ opinions about water. We asked respondents whether water quality issues are mainly a problem in isolated parts of the state or affect residents statewide. We randomly assigned respondents to receive a slightly modified version of the question in which we varied the frame of reference. One third of respondents were assigned to a control group that received the question without any geographic referent. The other two-thirds of respondents received a version of the question that either referenced “Milwaukee” or “Eau Claire.”

A substantial majority of respondents said “statewide concern” across treatment conditions. However, there was a statistically significant increase in the percentage saying “statewide concern” among those who received the Eau Claire reference compared to those who either received the Milwaukee reference or the version of the question that did not name a place. Indeed, there was no difference in opinion between the Milwaukee and control conditions, suggesting that respondents think about water quality as an urban issue absent any additional information. As one resident told a reporter after learning his small rural community had tested for high levels of PFAS, “We didn’t have a whole lot of big city issues until now.” We find suggestive evidence that rural residents were the most sensitive to these geographic framing effects.

Governments around the world are working to increase community resiliency to natural and human-made disasters. Strategies include reducing vulnerabilities to environmental hazards, identifying effective mitigation technologies, educating the public about environmental risks, and crisis planning to reduce response times and economic losses. Community engagement is critical to these efforts. However, communicating PFAS risk is challenging. Wisconsin’s drinking water standard is new and does not yet apply to groundwater. A federal regulation, expected later this year, may set a lower PFAS limit. Testing will likely raise concerns about liability and cost. Who will pay for remediation remains uncertain. The Wisconsin Court of Appeals will soon hear a case on whether the state has the legal authority to enforce PFAS cleanups pursuant to its authority under the Wisconsin Spills Law. Scientific understanding of the adverse health impacts of PFAS is also evolving.

This research is part of a larger, two-year study of public understanding of PFAS in Wisconsin. New regulatory standards and testing requirements mean residents will hear about more instances of elevated levels and the need to mitigate and manage PFAS risks. In our first survey, conducted last June, we found that a large majority of Wisconsin residents are worried about PFAS contamination. In contrast to the deep partisan divides that typically define Wisconsin politics, water quality remains a bipartisan issue. Differences in concern, however, may inform communication strategies going forward. For example, concern is higher among those who pay close attention to politics, suggesting that more concerted efforts may be needed to engage less politically engaged residents. We will continue to survey Wisconsin residents about water quality issues in the coming year. One thing we will be looking at is whether the difference we observe between those on public water systems and those on private wells changes as testing in the state gets underway. We will also begin conducting focus groups to better understand local conditions and how risk information is framed and shared in communities across Wisconsin. With our colleagues in Biological Sciences, Economics, Education, Engineering, Law, and Political Science, our goal is to strengthen state and local resilience to possible PFAS contamination and other water-related hazards.

Dr. Jill McNew-Birren and Prof. David Strifling also contributed to this post.