By Shereen Siewert | Wausau Pilot & Review

An updated risk assessment for a Wausau park shows toxic compounds at levels high enough to cause an “unacceptable cancer risk,” prompting recommendations to immediately limit exposure for the men, women and children who use the space to play and gather.

So far, city officials haven’t said whether they’ll comply.

The May 31, 2023 letter sent by the Wisconsin Department of Health Services outlines a new analysis performed for areas in Riverside Park that are slated for future cleanup. Most of the park, located on the city’s west side on the banks of the Wisconsin River, do not pose a concern at this time, nor do adjacent residential properties, the department’s memo states.

But for the areas that do have high levels of dioxin, state officials are recommending interim actions that include covering the contamination zone with landscaping fabric and clean material, such as wood chips, and using signage to notify people about the potential exposure there. The city has a remedial plan to clean up the contaminated soil, but the process has not yet begun – with no clear timetable in sight.

Learn more about dioxin and its impacts on human health here.

The most recent DHS report was summarized by Dr. Jeremiah Yee, a toxicologist with the Bureau of Environmental and Occupational Health, in response to a request from Dist. 3 Alder Tom Kilian. The analysis appears to back up claims made by environmental advocates who for years begged Wausau to test and clean up the park, a fight that met fierce resistance from city officials.

The controversy erupted in early 2018 when test results revealed high levels of dioxin in the soil beneath a culvert emptying into the park. The culvert neighbors an area that once housed a cold storage building at the former SNE plant. One area of the cold storage building was used as a “drum accumulation area” for hazardous waste, which was later moved to the main WAULECO facility.

Photo of culvert discharging into Riverside Park, taken March 17, 2018. Credit: Shereen Siewert/Wausau Pilot and Review

The land next to the park, a portion of which is now owned by the Sentry Insurance subsidiary, has been subject to decades of remediation efforts to remove toxic substances from the soil arising from the use of pentachlorophenol, or Penta, a potent pesticide used in wood manufacturing at SNE. A Phase I environmental study conducted by engineering firm REI in May 2019 showed several areas of concern, pointing to soil contamination from a 3M petroleum spill and dioxin “likely deposited on the property from surrounding historical industrial uses,” according to city documents.

“This site clearly has impacted groundwater which has migrated off the Wauleco site and onto adjacent properties including Riverside Park,” the assessment states.

3M’s Wausau plant is also adjacent to the park.

City resistance

Some city officials’ skepticism was rooted in a 2018 toxicologist’s report which concluded that there is “no apparent health hazard for people using the Riverside Park and residents living in the Thomas Street neighborhood” due to soil contamination. But that report failed to take into consideration potential cancer risks associated with dioxin, prompting a nationally-known Harvard-trained toxicologist who participated in the U.S. Environmental Protection Agency’s cleanup activities for more than 20 years to weigh in on the analysis, which he called “inadequate and incomplete.”

But many city officials were not swayed, and repeatedly discredited attorneys, scientists, engineers and residents who were demanding action to protect the community’s health. For example, in a May 2018 radio interview on WSAU radio, then-Mayor Rob Mielke, referring to the dioxin controversy, said “It gets frustrating when you have some of the rabble-rousers, and their innuendo, and out and out just dishonesty.”

Public Works Director Eric Lindman was equally vocal in his reaction to residents, suggesting that their stated concerns were merely a scare tactic to stall a planned Thomas Street project that also met resistance from people living in the neighborhood. A WSAW report published in May 2018 quotes Lindman as saying “I do feel that this is a way to try leverage to stop the project and you know unfortunately put a fear into the general public that I don’t think is warranted.”

It gets frustrating when you have some of the rabble-rousers, and their innuendo, and out and out just dishonesty.

Then-Mayor Robert Mielke, in a May 2018 radio interview

Months later city officials issued a news release declaring the park was safe for the public, a proclamation made before independent testing results funded by a citizen group were even released. The city based its public assurances on years-old data and a single test result in Riverside Park performed WAULECO earlier the same year. The WAULECO testing was requested by the state Department of Natural Resources following a Wausau Pilot and Review report that detailed decades of burning of wood waste at the former manufacturing site, which is adjacent to the park.

And Lindman, in 2019, directly advised city officials not to test at Riverside at all, despite recommendations from state officials and a strong public outcry.

After months of contentious debate, city officials did in 2020 approve testing in the park, at 100 Sherman St., Wausau, to define the extent of contamination in the area. Those results were telling: Tests in April 2020 showed multiple exceedances of state DNR soil standards. That effort was followed in September 2020 with additional soil borings showing that the extent of contamination in the soil was wider than previously recorded, according to city documents.

Testing was performed in September at the park, at 100 Sherman St., Wausau, to define the extent of contamination in the area after previous test results from April showed multiple exceedances of state Department of Natural Resources soil standards. In one sample, dioxin concentration was nearly four times the state standard for residential settings. That sample, taken at the base of the hill in Riverside Park, is not located in the woods or brush but instead is located in the open at the westernmost edge of the park’s grassy area where families and children play. Spots with several samples with higher levels of contamination are adjacent to nearby homes.

In August 2021, Wausau officials said they would move ahead with an environmental remediation plan that would be submitted to the DNR that year.

But the remediation plan for the park has dragged on, with the Department of Public Works citing a variety of reasons for the slow pace. In August last year, Lindaman wrote in an update to the committee that the bidding would occur by the end of the year. That deadline, along with a subsequent date, was missed. And in December, Lindman said his department was awaiting soil test results from samples taken November and that additional samples need to be collected.

“As long as the area is defined with the latest round of sampling then the project should be able to be bid in Jan/Feb 2023,” the Dec. 5 updated noted.

City documents show bids for the Riverside Rail Corridor Project were finally opened in April. But neither city nor DNR officials have responded to questions regarding the status of the plan and when work will begin.

Former Dist. 1 Alderman Pat Peckham, who at the time was chair of the parks and recreation committee, was a vocal skeptic of concerns raised by the citizens group and said during a January 2019 meeting he was not personally convinced that health risks in the park exist. He has since retired.

In a June 2 email to Wausau Pilot & Review, Peckham said the first assessment was based on a scenario where an adult and child would spend time playing in the dirt in the spot in the park believed to be most contaminated. The scenario had them going to the spot three times a week for 36 weeks (108 visits) over a theoretical summer. The conclusion was that, even with the assumption that the child would ingest some of the soil, there was “no unreasonable risk” to residents or park users. A question was raised about cancer risk not being included in the calculations, so the main toxicologist working on the assessment, Clara Jeong, factored in cancer risk and again found “no unreasonable risk.”‘

Peckham said it “has always been my position that the residents of the Thomas Street corridor and users of Riverside Park ought to be given accurate and reliable information on the safety of living and recreating in the area. It had been my impression when I was first elected to the city council in 2016 that previous city officials had not done enough to respond to the concerns of those citizens.”

“The new recommendation, based on multiple testing efforts that identified areas where contamination was most concentrated, is valuable information and is just the sort of thing I was hoping would come of a DHS assessment of the city’s newest soil analysis,” Peckham wrote.

Dist. 3’s Kilian, a founding member of the environmental group Citizens for a Clean Wausau, said he hopes the city will heed health officials’ advice to keep park-goers safe.

“I thank DHS and DNR for their work on this site, and I hope that the City of Wausau promptly heeds the recommendations from DHS that the department laid out in its letter,” Kilian said.

Wausau Pilot & Review reached out to Mayor Katie Rosenberg, Public Works Director Eric Lindman and Parks Director Jamie Polley early Thursday asking about next steps and inquiring on the status of the cleanup process. None have replied.

What is dioxin? The EPA explains

Dioxins refers to a group of toxic chemical compounds that share certain chemical structures and biological characteristics.

  • Dioxins are called persistent organic pollutants (POPs), meaning they take a long time to break down once they are in the environment.
  • Dioxins are highly toxic and can cause cancer, reproductive and developmental problems, damage to the immune system, and can interfere with hormones.
  • Dioxins are found throughout the world in the environment, and they accumulate in food chains, concentrating mainly in the fatty tissue of animals.
  • More than 90% of typical human exposure is estimated by EPA to be through the intake of animal fats, mainly meat, dairy products, fish, and shellfish.

What does dioxin look like?

Pure dioxin looks like white crystalline needles. In the environment, however, it generally is dispersed and attached to soil and dust particles and is invisible to the eye.

Where does dioxin come from?

Industrial activities: Dioxin is not produced or used commercially in the United States. It is a contaminant formed during the production of some chlorinated organic compounds, including a few herbicides such as Silvex. Over the past decade, EPA and industry have been working together to dramatically reduce the production of dioxin and its release to the environment.

Although environmental levels of dioxins have decreased in the last 30 years, dioxins are extremely persistent compounds and break down very slowly. In fact, a large part of current exposures to dioxins in the United States is due to releases that occurred decades ago (e.g., pollution, fires).

Even if all human-generated dioxins were eliminated, low levels of naturally produced dioxins would remain. EPA and its government partners are looking for ways to further reduce dioxins entering the environment and to reduce human exposure to them.

How can dioxin affect my health? The World Health Organization explains

Short-term exposure of humans to high levels of dioxins may result in skin lesions, such as chloracne and patchy darkening of the skin, and altered liver function. Long-term exposure is linked to impairment of the immune system, the developing nervous system, the endocrine system and reproductive functions.

The developing fetus is most sensitive to dioxin exposure. Newborns, with rapidly developing organ systems, may also be more vulnerable to certain effects. Some people or groups of people may be exposed to higher levels of dioxins because of their diet (such as high consumers of fish in certain parts of the world) or their occupation (such as workers in the pulp and paper industry, in incineration plants, and at hazardous waste sites).

Read the DHS assessment letter: