The EPA finalized stricter lead cleanup levels and more soil testing for thousands of residential properties in Butte on Monday.
The decision cut the threshold that triggers cleanup of lead in soils within priority residential areas by nearly a third, from 1,200 parts per million (ppm) to 456 ppm.
Now, if soil samples show lead levels of more than 456 ppm, the soil will be removed and replaced with clean fill.
The EPA is also expanding the program that tests residential soil. More than 7,000 additional properties will now be sampled for lead and, if needed, cleaned up.
The EPA proposed the changes in June. The plan received pushback from some residents who wanted the cleanup levels to be even stricter, as the EPA once proposed several years ago.
The residential work is part of a larger cleanup under the EPA’s Superfund program. Butte’s mine waste is among the largest and most complex hazardous waste cleanups in the country.
