In 1983, the State of Montana filed a lawsuit against the Atlantic Richfield Co. (ARCO) for injuries to the natural resources in the Upper Clark Fork River Basin. The lawsuit, brought under federal and state Superfund laws, sought damages from ARCO, contending that decades of mining and smelting in the Butte and Anaconda areas had greatly harmed natural resources in the basin and deprived Montanans of their use.

In 1989, the Environmental Protection Agency (EPA) filed another lawsuit to establish ARCO’s liability for remedial clean up of the basin. The state has settled its lawsuit through a series of settlement agreements completed in 1999, 2005 and 2008.

1999 Settlement – Montana v. ARCO

The first phase of the lawsuit went to trial in March 1997. The state and ARCO reached a settlement agreement on a large portion of the lawsuit in June 1998. In November 1998, the state, ARCO, federal government and Confederated Salish and Kootenai Tribes reached a second agreement that incorporated the NRD settlement and also a settlement of ARCO’s remedial liability to EPA and the state for cleanup of Silver Bow Creek. The Court approved both settlement agreements in April 1999.

The 1999 settlement called for ARCO to pay the state $230 million ($215 plus $15 million in interest). The payment included:

  • $129 million (including $9 million in interest) for the restoration of natural resources in the Clark Fork Basin. This money was deposited in a special revenue fund known as the Upper Clark Fork River Basin Restoration Fund.
  • $86 million (including $6 million in interest) for the state’s cleanup of the Silver Bow Creek area west and north of Butte in accordance with EPA’s Record of Decision.
  • $15 million to reimburse the state for all of its costs in bringing the lawsuit through December 31, 1997.

As of December 2010, the Governor has approved 121 grants totaling $112million of the 1999 settlement funds.   In May 2012, the Governor approved a Final UCFRB Process Plan , that describes the new process the State will use to develop restoration plans and fund restoration projects in the UCFRB with the estimated $110 million remaining from the 1999 settlement.

2005 Settlement – Milltown Dam

A consent decree involving the state, EPA, ARCO and NorthWestern Corporation was filed in August 2005. The decree addressed the terms and costs of cleaning up the Milltown Dam Reservoir area east of Missoula and restoring the Clark Fork and Blackfoot Rivers at the site.

Under this Consent Decree, the State received approximately $13 million in total value for its natural resource damage claims, including the following:

  • $3.9 million for natural resource restoration from NorthWestern Corporation.
  • NorthWestern’s land (415 acres) and water rights at the site (2,000 cfs), which have an estimated value of about $2.5 million
  • a covenant from the U.S. Department of Interior (DOI) that the State’s restoration of this site will meet Montana’s bull trout obligations to DOI under the Streamside Tailings Consent Decree (value about $1.4 million)
  • implementation by ARCO’s contractor, Envirocon, of the State restoration plan at the site in the remediation project area (value about $5 million)

In addition, under the provisions of this Consent Decree, Montana is adding $7.6 million from the 1999 ARCO settlement for restoration at the Milltown site. For further information on the progress of the cleanup, go to the Milltown Dam page.

2008 Settlement – Montana v. ARCO

In February 2008, the state, EPA and ARCO reached a final settlement totaling $169 million. Of that, $96.5 million goes to DEQ for remediation of the Upper Clark Fork River site and $72.5 million goes to the state to restore the three remaining sites:

  • Butte Area One – $28.1 million
  • Smelter Hill Uplands – $13.2 million
  • Upper Clark Fork River – $26.7 million