As the state Department of Environmental Quality (DEQ) gets closer to finishing the clean-up of dioxin-contaminated soil at Butte’s smallest Superfund site, the Montana Pole Plant, some members of the community are still concerned about the human health risk.
In response, a risk assessment expert visited Butte to break down options for protecting human health with a contaminant that just won’t break down.
“This is one of the most toxic compounds, if not the most toxic compound we ever deal with," said Aimee Reynolds with Montana’s DEQ.
Reynolds emphasized to the crowd of 20 gathered at Quarry Brewing on Tuesday just how serious the health threats from dioxins are.
“They have reproductive and developmental effects, they can damage your immune system, they interfere with your hormones and they do cause cancer,” said Reynolds.
Worse, they’re everywhere. Some naturally occur in the environment. The more toxic ones tend to be byproducts of industry - like the wood preservatives used at the Montana Pole Plant. But since dioxins don’t degrade, evaporate, or break down, they’re extremely hard to get rid of.
"We have to somehow decide what's an OK level to leave behind. So we use risk assessment to do that," Reynolds said.
Reynolds parsed out the agency's updated criteria for calculating the levels of exposure they consider to be protective of human health, based on whether the land is under industrial or recreational use.
She said that because dioxins are so persistent, remedial options are limited. And some don’t work on the huge quantities of contaminated soil and groundwater found at Superfund sites.
"So the good news is, once the liquid carrier is removed, the dioxin sticks to the soil. It doesn’t keep moving on its own," said Reynolds.
Which is why, after trying other methods to deal with dioxins at Montana Pole, DEQ has decided to treat, cap, and store the approximately 200,000 cubic yards of dirty soil there.
Dave Hutchins, a scientist and board member of the Citizens Technical Environmental Committee, said he still has questions about the safety of the neighborhood bordering the site, but that the presentation, "Confirmed the levels that they’re going to clean up to are in fact protective. I just hope we actually get the cleanup they’re talking about."
DEQ has been in charge of the Montana Pole site for the last 21 years. The agency is currently adjusting the cleanup standards for dioxins to be more protective and working with the county on the final treatment and land use plan.