The Wisconsin DNR's 2015 Water Utilities Report, In Context

On July 29, the Wisconsin Department of Natural Resources released its 2015 report on the state's public drinking water utilities detailing information about costs, contaminants and infrastructure status. Overall, the report offers a positive assessment of the drinking water sources that about three-quarters of Wisconsinites rely upon. 

Coliform bacteria, nitrates, and radium remain the most widespread contaminants, but 94.6 percent of municipal water samples tested in 2015 met the health standards the DNR enforces under the federal Safe Drinking Water Act. Other details in the report include statewide numbers on contaminant testing and compliance violations, a summary of enforcement actions the DNR took during 2015, and information about loans provided for water utility improvements.

Drinking water, its sourcing and threats to its quality is very complex and the issue is not getting simpler anytime soon. For Wisconsinites skimming or reading the state's 23-page report, additional background about drinking water will help put it in perspective and aid in better understanding about what comes out of the tap.

This report isn't a complete picture of Wisconsinites' drinking water.

The DNR report covers people get their water from a utility, but one-quarter of Wisconsin's population — nearly one million households — relies on private wells for drinking water. Utilities must comply with state and federal regulations, whereas there are very few rules for private wells following their construction. Private well owners bear the responsibility for making sure their water is safe, without the personnel and revenue a public utility may have for treatment and monitoring. 

In a given area, the quality of well and utility water might be very different. For instance, public water utilities in Kewaunee County reported no detections of coliform bacteria in 2015, even though this type of contamination is a widespread problem in its private wells. This is likely because the area has relatively few public utilities, and those utilities disinfect their water. The Wisconsin Well Water Quality Viewer, developed by researchers at the Center for Watershed Science and Eductaion, is a good place to learn more about well water contamination across the state.

Most Wisconsinites drink groundwater, not lake water.

Wisconsin may border two of the Great Lakes, but those are not the state’s primary source of water. Eastern Wisconsin's heavily populated areas draw surface water from Lake Michigan and a few thousand people in northern counties (though fewer than one might assume) drink Lake Superior water. But the majority of drinking water in Wisconsin is sourced from groundwater wells, mostly because the state is rich in that resource.  The DNR's report indicates public water utilities pumped 82,793,173,044 gallons from Lake Michigan and Lake Superior in 2015 versus 95,148,910,360 gallons of groundwater.

Drinking water problems vary greatly from one locality to another, and even one well to another. So do utilities' treatment practices.

As geology and human activities change from place to place, so do the contaminants that might be found in water supplies. Large areas of eastern and western Wisconsin have a karst geology in which groundwater can be particularly vulnerable to contaminants running off from farms and roads. Other parts of the state contend with natural deposits of dangerous chemicals like arsenic and radium — the latter being one reason that the city of Waukesha sought and successfully acquired access to Lake Michigan's water through the Great Lakes Compact.

Regulations also address surface water and groundwater in different ways. One very important difference is that utilities using surface water must disinfect their water — systems using groundwater don't have this requirement, unless bacteria have been detected in testing. The vast majority of Wisconsin utilities that source groundwater still choose to disinfect. However, because of inherent differences in drinking water sources, and because of the discretion regulations give local utilities, treatment practices are all over the map.

While the DNR's report covers contaminants on a statewide level, problems with drinking-water quality are often intensely local, from bacteria in northeastern Wisconsin to industrial chemicals in Sauk County. Drinking water in the U.S. has been made safer over the last century: Public-health professionals generally consider the rise of disinfection, corrosion control, and other treatment practices to be triumphs that have saved thousands of lives. But the report doesn't offer a geographic analysis of contamination, which makes it more difficult to understand what’s happening specific places with problems, despite broader improvements in water quality.

The amount of a contaminant acceptable to regulators isn't necessarily safe.

The DNR's report reflects water samples that have exceeded the Environmental Protection Agency's maximum contaminant levels, or MCLs, for different substances. An MCL is a level of contamination at which a utility might be required to add new treatments, conduct additional monitoring and testing, and/or notify the public about the issue. But an MCL is not a definitive benchmark of water’s safe or healthy.

When setting MCLs, the EPA considers what concentration of a contaminant might cause health problems, but can also weigh this against different factors, chiefly the costs of any additional water treatments. Moreover, an MCL applies to what is detected in a given sample of water at one point in time, not to cumulative effects of exposure to a contaminant over a longer period. It's also possible that a person could be exposed to an amount of a contaminant exceeding its MCL and not suffer health problems as a result.

The report emphasizes this latter point: "It is important to note that a violation of a health-based standard does not mean that people who drank the water experienced adverse health effects; it means users were exposed to a contaminant at a level deemed by U.S. EPA to pose an unreasonable risk to health, or that the system failed to treat its water to the extent necessary."

Lead contamination helps illuminate some of the tensions involved in setting pollution standards. The EPA's MCL for lead is 15 parts per billion. A Washington Post report published in January emphasized that this level is "a regulatory measure, not a public health one." Researchers studying the lead crisis in Flint, Michigan told the Post that levels as low as 5 ppb could be a cause for concern. The EPA regulations do kick in additional requirements when more than 10 samples in an area exceed the MCL, but it's important to understand that lead's health effects are cumulative — a little at a time can do serious damage over the long term, especially to children. State regulators have also admitted that there are shortcomings in how they monitor for lead in drinking water.

The EPA regulates dozens of water contaminants under the Safe Drinking Water Act. That law also charges the agency with researching and adding "emerging contaminants" to that list. Ongoing research about bacteria and viruses in groundwater right in Wisconsin highlights how much new knowledge about water officials at all levels have to follow and consider.

In this context, water standards represent a balancing act, rather than a direct indication as to how much of a given contaminant is safe. The DNR's press release about its report touts "96 percent of water systems with no samples exceeding health-based standards for regulated contaminants." That statement is a correct application of federal standards as they exist, but it doesn't acknowledge that other factors than health inform these standards, nor does it address potential problems that more incremental contamination could pose.

Wisconsinites can keep up with treatment and testing at their water utilities.

Wisconsin residents who want more detail about water quality in their area and what their utilities are doing can start by searching DNR's online databases. Users can search by utility or by contaminant to get details on sampling results, treatment practices, and the testing and public notifications utilities are required to carry out. The searching can be a bit cumbersome and the information may have gaps, but the data can still be quite helpful.

Without loans, water utilities would have a harder time updating their infrastructure.

The DNR report provides information about state and federal funding for local water utilities, including a list of low-interest loans provided to specific communities for drinking-water infrastructure improvements. These latter funds, totaling just over $35 million pay for projects like replacing old water mains, constructing new wells and adding new treatment processes.

Paying for these needs isn't easy. There are more than 600 water utilities in Wisconsin, and the majority have a clientele of only a few hundred or even a few dozen people. Many are too small to have a full-time engineer or manager on staff. Wisconsin's Public Service Commission limits how a utility can use ratepayer money, and customers may balk at rate hikes. Infrastructure of all kinds is aging, while funding is expensive and the issue could be considered politically unexciting. But as communities encounter new needs, state and federal programs represent an important lifeline for safer drinking water.