The Environmental Protection Agency (EPA) announced it will do additional cleanup of residential yards in East Helena that have been contaminated by lead.
The EPA’s new decision lowers the amount of lead in soil required to trigger a cleanup.
In a statement, the agency said a “better understanding” of the health effects of lead exposure motivated the update.
The agency has already replaced soil in hundreds of yards contaminated by a lead smelting plant that operated in the town for over a century.
Officials at the East Helena and Butte superfund sites said they are assessing new national guidance that could further lower residential cleanup requirements in both communities.