DNR adds 51 sites to Wisconsin list of impaired waters

The Wisconsin Department of Natural Resources’ biennial survey of surface water pollution across the state added 51 bodies of water to the state’s impaired waters list, which tracks which bodies fail to meet the state’s surface water standards. 

The survey found that 80% of assessed waters meet the state’s standards, but the remaining one out of every five of the state’s water bodies is polluted with contaminants such as phosphorus, algal blooms, e. Coli or PFAS. 

The survey resulted in good news and bad news for water quality across the state. Along with the 51 bodies added to the list, 20 bodies are now considered to be “in restoration” and another 22 are slated to be removed from the list because they now meet state standards. 

The newly polluted waters are mostly affected by phosphorus, degradation of aquatic plants and PFAS. One-third of the state’s impaired waters are polluted by phosphorus. 

The addition of PFAS-affected waters was expected because surface water standards for the harmful “forever chemicals” were instituted last year. The continued prevalence of phosphorus pollution highlights the difficulty the state faces when reining in contamination largely caused by agricultural runoff. 

Kristi Minahan, the DNR’s water quality standards specialist, says water pollution trends in the state have remained consistent over recent surveys, but the list reiterates the agency’s focus on reducing phosphorus pollution. 

“It’s always a mixed bag in terms of having some water bodies added, some delisted every cycle,” she says. “We know we’re going to have some of each.”

The DNR visits new bodies of water each year that haven’t been assessed before. There are always new things to be found,” Minihan says. “The main takeaways for this year are overall the trends have remained pretty much the same in the last few listing cycles. Phosphorus continues to be a widespread issue … that is a real focus for the department right now.”

Phosphorus is an essential nutrient for plant growth. Too much of it in a body of water, however, can cause harmful algal blooms. The chemical gets into the water through two methods: point source and nonpoint source pollution. 

Point source pollution comes from one defined location. Human waste, for example, contains a lot of phosphorus, so the treated water released by a sewage treatment plant typically contains some phosphorus. Point source polluters are required to obtain permits from the DNR that require them to limit the phosphorus in the water they return. 

Nonpoint source pollution doesn’t come from a single discrete source. Agricultural runoff is an example of nonpoint source pollution because manure used to fertilize fields contains phosphorus. 

Nonpoint polluters aren’t required to obtain the same type of permits from the DNR as point source polluters. They can take steps to reduce how much they’re polluting, however, such as installing a buffer zone between a farm field and a body of water to prevent manure from running off into the water. 

Bodies of water “in restoration” are under DNR plans to limit how much phosphorus enters that body. The total maximum daily load (TMDL) plans set a ceiling for the amount of phosphorus entering the water.  These TMDLs allow several producers of phosphorus pollution to coordinate their efforts to reduce the emissions across a watershed. A sewage plant can only do so much to reduce the phosphorus it emits, for example, yet under a TMDL, the plant can work with farms that share its watershed to install buffer zones or restore streambanks. 

Minahan says that even though phosphorus remains a concern around the state, there is evidence that TMDLs can be effective once they’re in place. 

“If you look at the long-term trend data we have around the state, phosphorus is really a success story with that,” she says. “We have seen across the board declines in phosphorus over time. It’s very promising. [There’s] certainly a lot of work to be done still.”

However, clean water advocates warn that stronger steps should be taken to prevent phosphorus pollution in the first place. Sara Walling, the water and agriculture program director with Clean Wisconsin, says there are limited enforcement options in dealing with nonpoint phosphorus pollution, makes it necessary to get agricultural producers across the state on board with reducing their phosphorus output. 

“There’s still a lot of need in tightening up our nonpoint pollution efforts and doubling down on the programs that support nonpoint pollution controls,” Walling says. “A number [of waters] have been moved into the restoration planning phase, while that’s great, they really still do not include any enforcement provisions on the nonpoint source side. Those TMDLs don’t do anything to require nonpoint reductions to get us closer.”

“The needle hasn’t really moved a lot when it comes to the issues that are creating these impairments with phosphorus as the main pollutant,” she continues. “It really means we need to keep our eye on the ball with helping agriculture reduce its phosphorus pollution to surface waters.”

Walling adds that the list of impaired waters only includes waters contaminated with pollutants that the state has set standards for. Other known pollutants, such as nitrogen, continue to harm bodies of water, but they aren’t tracked and the locations they pollute aren’t counted. Because much of Wisconsin’s water winds up flowing down the Mississippi River and into the Gulf of Mexico, better controlling nitrates here could help solve problems downstream, she adds.

The state has a number of programs aimed at enlisting agriculture to join clean water efforts. Producer-led watershed grants have been regularly cited as a conservation success in the state. Yet Walling says that more needs to be done to make sure everyone in a given watershed is pushing in the same direction. 

“What we need is the buy-in from the players to want to do more to resolve this issue,” Walling says. “I think we’re seeing a lot of great progress in that, the producer-led watershed districts are a great example of that. There needs to be a willingness on everybody’s part on the role we all have to play in our water quality picture in the state and a willingness to take on the work.”