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Congressional District # 08


EPA ID# MND057597940
Last Updated: March, 2015

Site Description

The St. Regis Paper Company (St. Regis) Superfund site occupies 125 acres within the exterior boundaries of the Leech Lake Band of Ojibwe Indian Reservation in the city of Cass Lake in Cass County, Minnesota. The site is located north of the Chippewa National Forest and west of Pike Bay and Cass Lake.

The St. Regis Paper Company began wood treatment activities at the site in the 1950s while leasing the land from the Great Northern Railroad (now the Burlington Northern Santa Fe Railway Company (BNSF)). The company pressure-treated lumber with creosote, pentachlorophenol (PCP), and copper chromium arsenate and discharged wastewater from these processes into a number of disposal ponds located at the site. Between 1957 and 1960, wastewater and sludges were hauled from the ponds to a pit within the former Cass Lake city dump and burned. The disposal from the ponds occurred almost daily at an estimated rate of 500 gallons per day for a total of 547,500 gallons over the three-year period. From 1960 to 1975, the company hauled unknown quantities of sludge to the city dump pit. The pit, containing ash and unburned residuals, was eventually covered.

EPA placed the St. Regis site on the Superfund National Priorities List in 1984. In 1985, Champion International Corporation (Champion) acquired the property through a merger with the St. Regis Paper Company and closed site operations. A large portion of the former operations area was then deeded to the city of Cass Lake. Other portions of the site are located on BNSF and Cass Forest Products properties. Champion was acquired by International Paper (IP) in 2000 and IP is the current owner of the former Champion portion of the St. Regis site.

Site Responsibility

The St. Regis site is being addressed through potentially responsible party (PRP) actions under state and federal oversight. EPA conducts oversight of PRP work at the site with assistance from its support agency partners, the Leech Lake Band of Ojibwe (LLBO) and the Minnesota Pollution Control Agency (MPCA).

Threats and Contaminants

Groundwater, soil, and sediment on and in the vicinity of the St. Regis site have been contaminated with polycyclic aromatic hydrocarbons (PAHs), heavy metals, and pentachlorophenol (PCP). Dioxins and furans, impurities in PCP, are also chemicals of concern (COCs). 

Human exposure to dioxins and the other COCs at the site could occur through ingestion of contaminated soil and dust or groundwater. Long term exposure could cause cancer or have other toxic effects.

Cleanup Progress

In 1986, the Minnesota Pollution Control Agency (MPCA) signed two Minnesota Enforcement Decision documents which outlined the response actions for each cleanup area at the site. These areas include the treatment facility, the Cass Lake City Dump Pit, a contaminated soil vault, and the extension of the Cass Lake municipal water system. In 1987, then owner Champion constructed groundwater extraction wells at both the treatment facility area and the city dump area. The contaminated groundwater is extracted, treated onsite, and then discharged into a channel between Pike Bay and Cass Lake. An onsite containment vault was constructed at the site which contains 37,500 cubic yards of contaminated soil and sludge from the wastewater lagoons and 4,500 cubic yards of contaminated soil and sludge from the city dump pit. Current owner International Paper (IP) has monitored and maintained the treatment system and soil vault since 2000.

As a result of Five-Year Reviews (FYRs) conducted in 1995 and 2000, EPA conducted fieldwork in October 2001 to collect data from the site to evaluate whether the response actions remained protective of human health and the environment. Dioxin, at levels above the Superfund Removal Action Levels, was encountered in shallow soils on the site property. In August 2003, EPA ordered IP to conduct additional confirmatory and delineation sampling. Removal actions for shallow soil above 1 ppb TEQ Dioxin were conducted during FY 2004, 2005, and 2006 by IP and BNSF under consent orders from EPA. EPA also ordered IP to conduct a Human Health and Ecological Risk Assessment. Sampling of soil, house dust, sediment, surface water, plants, invertebrates, and fish, in support of human health and ecological risk assessments was also conducted during FY 2004 by IP under an EPA order.

In 2005, after analysis of the data from the sampling, EPA decided on an interim cleanup approach for dioxin and arsenic contamination in residential settled dust that was above screening levels. Necessary interim cleanup actions included an initial comprehensive cleaning of all area residences with carpet replacement, HEPA vacuum cleaning, wet wiping, steam cleaning soft furniture, and cleaning of draperies and rugs. In addition, supplemental periodic cleaning of homes, clean soil yard cover, and dust suppression to the unpaved roads was required. In 2006, under an order from EPA, International Paper conducted all initial cleanings, the yard work, dust suppression, and continues the periodic house cleanings. Periodic cleanings are required until final cleanup actions are completed.

A 2005 FYR of the site also concluded that additional information was needed to determine whether the groundwater remedial actions were protective of human health and the environment. IP drilled new soil borings and monitoring wells in 2006, 2007-2008, and 2009 and defined the extent of a tarry liquid in the City Dump plume. IP also conducted a site-wide pumping test and an investigation near ground water wells owned and operated by the LLBO to determine the effectiveness of the till between the upper aquifer and the lower aquifer from which the Band takes drinking water.

In 2008, EPA approved the human health portion of the risk assessment and concluded that there are unacceptable risks to human health and the environment from contaminated soil at the Site. An Administrative Order on Consent for a Feasibility Study to develop remedial alternatives for soil clean up at the site was signed by EPA and the PRPs in September 2008. EPA approved the Feasibility Study Report in April 2011 and announced a preferred remedy for contaminated soil in a Proposed Plan in June 2011. EPA’s agency partners and many residents of the Cass Lake area opposed the preferred remedy and EPA did not select a soil remedy at that time. The agency partners also asked EPA to require additional soil sampling before selecting a remedy and EPA agreed.  EPA then formed a soil technical workgroup to plan the collection of additional soil data. IP took additional soil samples in 2012-2014 and will use the results to revise the FS.

EPA is currently working with its agency partners and the PRPs to revise the Feasibility Study by mid-2015 and then issue either a new proposed plan or a Record of Decision in summer 2015.

The 2010 FYR Report found that hydraulic capture was incomplete in the former operations area and possibly also in the City Dump burn pit area. IP collected groundwater and soil samples between 2012 and 2014 to evaluate contaminant plume capture in these areas, and will sample porewater in the channel connecting Pike Bay and Cass Lake in spring 2015. IP is also generating a new ground water model under the oversight of EPA and its agency partners to evaluate the overall effectiveness of the groundwater extraction and treatment system.

The 2012-2013 supplemental soil investigation found high levels of Site contaminants and visually contaminated soil to the water table in the southwestern area of OU2 where waste was historically dumped. The PRPs collected soil and groundwater samples in 2014 and 2015 to assess groundwater impacts in this area. Further samples will likely be collected in winter 2015/2016.

EPA plans to complete the fifth FYR of the St. Regis site by June 5, 2015.

Success Story

During the past 9 years, the level of effort on this site has been very high from EPA, state and Tribal regulators, the local community, and the potentially responsible parties.  Removal actions and interim remedial actions have been taken to reduce health risks to the local residents while EPA works to select a final cleanup remedy. 

Community Involvement

EPA held a public meeting in July 2012 regarding the additional sampling that will be done before a final soil cleanup action is selected. 

Congressional Interest

Congressman James Oberstar and Senator Klobuchar have maintained an interest in the St. Regis site. State Representative John Persell is the Superfund Coordinator for the Leech Lake Band of Ojibwe. Staff from Senator Al Franken’s office requested information on the Human Health and Ecological Risk Assessment in November 2012, and requested additional information from EPA in August 2013.

Property Reuse

The city of Cass Lake zoned the former operations area and much of the adjacent properties as commercial/industrial in January 2006. The surrounding residential properties are zoned residential. On October 8, 2014, the city of Cass Lake adopted a comprehensive plan establishing the city’s goals and priorities in redeveloping site properties.


Remedial Project Manager, U.S. EPA
leslie patterson (patterson.leslie@epa.gov)
(312) 886-4904

Community Involvement Coordinator, U.S. EPA
heriberto leon
(312) 886-6163




Site Profile Information

This profile provides you with information on EPA's cleanup progress at this Superfund site.


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