BUTTE, Mont. - Montana Department of Environmental Quality and Environmental Protection Agency officials say that a potentially harmful groundwater chemical plume could be lying beneath the Butte school district high school on Main Street.
The EPA released its preliminary assessment on the plume to Butte officials last week, but there are still a lot of things we won't know until the EPA finishes its investigation.
We do know that the plume was discovered back in 2009 when Naranche Stadium was being built and was initially considered a low risk factor by the DEQ, before new EPA standards passed in 2017, allowing for a re-investigation to open in 2019.
Now, the EPA says that chemicals found in the plume, such as PCE, a chemical often found in dry cleaning solvents, could present severe health risks (such as neurological disease and even cancer) to those exposed to it, if found to be in high enough concentration.
But that's a big 'if.' The data hasn't been updated in full since 2009, hence why the EPA is now investigating. But recent modeling from the DEQ suggests that the plume is still low risk.
"When we look at it, the risks that we're seeing aren't unacceptable risks if we calculate it out using a model," said Terri Mavencamp, the contaminated site cleanup bureau chief for DEQ. "So, we don't want people to jump to immediate concern."
As for when we'll have more answers? It should be in the upcoming months; the EPA will begin its on-site inspection for contaminants in the winter, which is the best season for lowing the possibility of transmitting contaminants.
"Under the site inspection, EPA will go out and collect some additional data to help them answer any questions that remain in terms of confirming that the risk is indeed low," said Dan Norris of DEQ.
In the meantime, the EPA will continue to collect data through short sampling in the coming weeks. This won't give all the answers that the winter's full-on inspection will, but it will paint a clearer picture of what we might dealing with.
ABC FOX Montana also contacted the Butte School District to learn if there are any contingency plans in place should officials deem the plume dangerous enough to require action, but they were not available for comment.