The U.S. Environmental Protection Agency (EPA) has proposed adding the site of Smurfit-Stone’s paperboard mill near Missoula, Mont., to its Superfund National Priorities List (NPL). If the site receives NPL classification it would become eligible for additional study and cleanup resources under EPA's Superfund program. A 60-day public comment period about the proposed listing began May 23, 2013.
In proposing that the closed paper mill be added to the list, the EPA says the site is contaminated with dioxins, furans, arsenic and manganese associated with the site’s wastewater and sludge ponds.
The paper mill opened in 1957 and closed in 2010. Prior to 1969, untreated wastewater was directed to storage ponds, according to EPA. After a primary sedimentation treatment process was implemented in 1969, the produced sludge was disposed of in on-site ponds. These ponds, among others, were found to have dioxin, furan, arsenic, and manganese contamination present.
Although shallow groundwater at the site appears to be contaminated, private residential and municipal drinking water wells are not believed to be affected at this time.