Superfund Site Profile

Investigation of the Smurfit-Stone Mill site is ongoing to determine the nature and extent of contamination. Several documents related to the remedial investigation of the site are available:


The 3,200-acre Smurfit-Stone Mill site is located 11 miles northwest of Missoula, Montana. A pulp mill operated on site from 1957 to 2010. The core industrial footprint of the mill site covers about 100 acres. Over 900 acres of the site consist of a series of unlined ponds used to store treated and untreated wastewater effluent from the mill, as well as primary sludge recovered from untreated wastewater. Some ponds initially used to store wastewater were subsequently drained and used for the landfilling of solid wastes from the mill.

Various hazardous substances were used or produced on site, including bleaching chemicals. The use of chlorine for the bleaching of pulp produces chlorinated organic compounds, including dioxins and furans, through the reaction of chlorine with residual lignin. The site includes landfills used to dispose of solid wastes including general mill refuse, boiler fly ash, lime kiln grits, ragger wire and asbestos.

Site activities and waste disposal practices on site may have caused a release of hazardous substances into the environment. A screening investigation by EPA determined that the site’s primary contamination sources include four sludge ponds, an emergency spill pond, an exposed soil pile adjacent to a landfill, a wastewater storage pond and a soil land farming area.