By Shereen Siewert

WAUSAU — New information has surfaced about potential contamination in what is known as the River Street neighborhood, even as residents and other concerned citizens are preparing to demonstrate outside City Hall to protest a planned road construction project through the area.

The demonstration is set to begin at 5:30 p.m. Tuesday, in advance of the 7 p.m. City Council meeting.

Demonstration participants say independent soil testing, in which two of four soil samples collected showed dioxins and furans that exceed allowable hazard limits, is a red flag that city officials are appearing to ignore by moving forward with the project.

Today test results have surfaced that show soils beneath a culvert discharging into Riverside Park showed levels of hazardous substances in 2006 that were six times that of the most recent round of testing on nearby property. Those test results were sent to DNR officials in 2008, and DNR officials forwarded the information to the Marathon County Health Department, according to court documents and emails that are all public record.

Despite those test results, the culvert remains on the city’s map and has not been closed or re-tested. The outlet discharges into the western portion of Riverside Park, just below the train tracks.

In addition, residents are raising concerns that water from private wells contaminated with Penta was used to water lawns and gardens in the 1980s, potentially spreading the contamination further throughout the neighborhood. The wells were discovered at a time when a “pool” of contaminated Penta was found floating on the groundwater under the SNE plant. Penta is the chemical that was used widely in manufacturing activity at the plant,

Then, city officials and DNR representatives went door to door in a four-block radius, visiting 200 homes to determine if private wells had been contaminated and warn residents not to use or install them in the area, according to documents contained in the papers of former U.S. Congressman Dave Obey, who represented Wisconsin for decades. Initially, no contamination was found. But a month later, a city employee discovered a 20-year-old homemade well dug into a basement floor in the 100 block of Edwards Street with a pool of water with Penta floating on top, according to the Marathon County Health Department.

A second well was also found, this time in the 1400 block of Cleveland Avenue, according to city documents. Both wells showed significant contamination, according to DNR documents.

In June 1986, then-Utilities Director Joe Gehin, who is now a city council member, alerted the DNR and the Marathon County Health Department about the wells, which he stated were used for “watering gardens” and “other non-potable purposes.” But despite contaminated water being routinely used to water lawns for decades, there is no record of surface soils being performed on those properties to assess the danger to the public.

Attempts to reach the residents from 1986 at each of the properties listed failed; both renters listed in city documents died of cancer-related illnesses, according to their obituaries.

Residents say they want more testing before the project moves forward to ensure that digging up the soil won’t be a risk to public health. Dioxins and furans don’t easily break down, but can later be spread by mechanical processes such as digging. A small percentage will leach and enter the deeper soil horizons and can eventually reach the groundwater, according to the National Center for Biotechnology Information.

Photo: This culvert, photographed on Feb. 27, 2018, discharges into Riverside Park. Tests from 2006 showed high levels of toxic substances in the soil beneath the culvert, which remains open. (Shereen Siewert/Wausau Pilot and Review)