Editor’s note: This story has been updated to clarify the chief concern expressed by critics of the project and the level of risk to the city’s water supply.               

By Shereen Siewert

WAUSAU — Crews replacing utilities as part of the Thomas Street project hit groundwater on May 16, fueling concerns from local advocates and neighborhood residents that soil contaminated by decades of manufacturing practices could threaten the city’s water supply.

While the risk to the city’s water supply may be low, the main concern is that groundwater was encountered in surrounding soils that may be contaminated. Groundwater gets polluted when contaminants—from pesticides and fertilizers to waste leached from landfills and septic systems—make their way into an aquifer, rendering it unsafe for human use. Ridding groundwater of contaminants can be difficult to impossible, as well as costly. Once polluted, an aquifer may be unusable for decades, or even thousands of years, according to the Natural Resources Defense Council. Groundwater can also spread contamination far from the original polluting source as it seeps into waterways, such as the nearby Wisconsin River.

City leaders have repeatedly dismissed the concern over potential groundwater contamination, sometimes calling it “baseless misinformation.” In 2014, DNR and AECOM representatives told city council members that groundwater was too deep to be encountered during the planned project, a claim echoed by City Council President Lisa Rasmussen during a contentious July 2017 meeting.

“We know for a fact about the existence of Penta, the groundwater is over 20 feet below the surface in that area,” Rasmussen said. “In a construction project you dig down 8 to 10 feet.”

Rasmussen made similar statements during the 2014 meeting, as highlighted in the video below.

But on Thursday, May 16, those claims were demonstrated to be inaccurate when groundwater was identified at the height of a planned utility placement.

Residents and environmental advocates have spent years trying to convince city leaders that the project could pose a danger to the community. Some evidence presented to the council included a 1998 environmental site assessment that showed the groundwater level just south of Thomas Street at about 10 feet below land surface — not 20 feet, as former DNR Hydrogeologist Lisa Gutknecht claimed.

In addition, a map of properties near the east end of the project area completed by Keystone Environmental Resources a former consultant for Wauleco, showed properties prone to groundwater basement flooding. Critics of the project are continuing to urge caution in this area given that river water levels are unusually high and these properties are prone to flooding in even normal circumstances.

A map of properties near the east end of the Thomas Street project, from WAULECO’s former consultant — Keystone Environmental Resources — shows properties that are prone to groundwater basement flooding. Source: Citizens for a Clean Wausau

The last round of testing at monitoring well W29, which is east of Emter Street on Thomas Street, directly in the project zone, had levels of pentachlorophenol at 1,100 parts per billion and that the prior round showed levels of 5,100 parts per billion. This monitoring well has shown depths to groundwater of 10 or 11 feet in the past, at times when the groundwater was not unusually elevated.

The grassroots environmental group Citizens for a Clean Wausau, which in April won a statewide Opee award from the Freedom of Information Council, posted this video Friday that shows previous statements made about the issue along with images captured this week:

Public Works Director Eric Lindman, in an email to Wausau Pilot and Review, said crews may need pump water while setting the manhole and first 200 feet of pipe, as groundwater has risen about two feet. Lindman said the rise is largely due to an upstream river drawdown.

“[The] contractor is going to wait a week or so to see once the river drawdown is complete if the groundwater will lower,” Lindman wrote. “If we do pump groundwater we will discharge to the sanitary sewer,” Lindman said. “We did not anticipate having to dewater so if this would be required it would be an additional cost to the project.”

The contractor will finish setting up temporary water to properties and then start digging and laying pipe next week, Lindman said.

DNR officials say they will connect with the city to ensure any plan to pump contaminated water complies with state statutes and codes.

Groundwater levels fluctuate seasonally and from year to year in response to changes in recharge from precipitation and surface-water bodies, according to the U.S. Geological Survey. (See: General Facts and Concepts About Groundwater)

The proposed reconstruction is the second phase of the project and involves a stretch of Thomas Street from Fourth Avenue to the Wisconsin River. Much of that area, known as the River Street neighborhood, has had a history of environmental contamination traced back to the widespread use of a chemical called Penta. Now classified by the World Health Organization as a known carcinogen, Penta was used in manufacturing at the former Crestline site. The current owner, Wauleco, was sued in 2008 by 144 people who claimed toxicity in the soil and groundwater caused cancer and other health problems.

The lawsuit alleged that Penta was routinely spilled and discharged into the environment over a 40-year-period. The Penta allegedly migrated into the River Street neighborhood, spreading dangerous levels of hazardous chemicals throughout the area.

The plaintiffs in the lawsuit in 2006 arranged for collection and analysis of surface soil and indoor dust samples throughout the River street neighborhood, which revealed the continued presence of dioxins more than 25 times the EPA recommended level, according to court documents.

Top photo: A test pit shows groundwater along Thomas Street in Wausau on May 16, 2019. Photo courtesy of Citizens for a Clean Wausau