An environmental watchdog group is warning that drinking water in La Crosse and other Coulee Region communities is contaminated with potentially dangerous levels of an industrial solvent linked to cancer and other diseases.
Trichlorethylene was found in the La Crosse water system between 2010 and 2015, the last year for which data are available. Although average levels were well below federal limits, it could still be cause for concern, especially for infants and fetuses, according to a national nonprofit organization.
The Environmental Working Group is drawing attention to the presence of TCE in 315 public drinking water systems that serve 14 million Americans.
A chemical found in industrial solvents as well as household products such as spot remover and correction fluid, TCE is one of the most commonly found groundwater contaminants, particularly at former commercial and industrial sites, according to the Minnesota Pollution Control Agency. Trichlorethylene contamination of an aquifer in Massachusetts was featured in the book and film “A Civil Action.”
TCE-contaminated water has been linked to birth defects, compromised immune systems and an elevated risk of cancer in cases of long-term exposure. Exposure to high levels can result in damage to the brain, nervous system and organs.
It can be ingested by drinking contaminated water and by inhaling fumes given off while bathing, washing dishes or doing laundry.
The EPA legal limit for TCE is 5 parts per billion (ppb) in drinking water, but EWG argues it could be harmful at much lower levels. Based on newer research, the Minnesota Department of Health in 2013 recommended 0.4 ppb — less than a tenth the federal limit — as a safety guideline, although there are no penalties for water utilities that exceed that lower threshold.
La Crosse is one of 18 Wisconsin utilities where contamination was detected, according to EWG. Individual samples have been as high as 1.65 ppb, although the system-wide average exceeded the MPCA recommended level only in 2013 and has never been above the federal legal limit.
At least one site was above the recommended safe level in 2016 and 2017, according to the city’s annual water reports.
Prairie du Chien’s water supply has been above 0.4 ppb each year and was at 0.69 in 2015. The highest levels reported in Wisconsin were in West Bend, Cedarburg and Grafton. Public water in Spring Grove, Minn., exceeded the state health guidelines each year and in 2015 was measured at 4 ppb.
Olga Naidenko, senior science advisor for EWG, said locally elevated readings could still be cause for concern even if the overall system average is below the threshold.
“It is a good reason to take a look,” she said. “There may be an underlying problem that needs to be investigated.”
The more than 43 million Americans who get water from private wells could also be at risk: TCE was found in about 3.5 percent of wells sampled by U.S. Geological Survey scientists in 2006.
Naidenko said wells near public utilities with elevated levels are more likely to have contamination.
“It’s really important for private homeowners to test,” Naidenko said.
The La Crosse municipal water supply last year complied with federal standards for more than two dozen regulated contaminants, although there were six reported violations of the EPA’s lead and copper rule. Water superintendent Lee Anderson said the problem resulted when samples were not taken in the month outlined in new rules.
EWG previously highlighted what the group considers potentially dangerous levels of chromium-6, an unregulated contaminant that has been linked to cancer.
The EPA in 2016 proposed banning TCE for certain uses under the Toxic Substances Control Act. But the agency twice extended the comment period and this spring moved the proposed rule to its long-term list, meaning no action is expected in the next 12 months.
EWG notes this action followed repeated requests from the chemical industry to delay the decision and suggests it could be years before any new regulations are implemented, if at all.
The agency says it is evaluating TCE under "conditions of use" guidelines, which are the administrator's determination of how the chemical is used.
"EPA has concluded that the risk evaluations for TCE will be more robust if the conditions of use are evaluated by applying the guidance and approaches required by the amended TSCA statute," an agency spokesman said Thursday. "If through its evaluation EPA determines that any of these conditions of use present unreasonable risks, EPA will take prompt action under the statute to address those risks."
Naidenko said under the Trump administration the agency has moved toward deregulation.
“We don’t find those trends encouraging,” she said.
Removing TCE from public water supplies can cost millions of dollars, but in-home water filters can also be effective.
The MPCA recommends activated carbon filters, which can be installed at a sink or appliance or on the entire home water supply. The agency says using a fan or ventilation system when boiling water or bathing can reduce airborne exposure.