Understanding the Superfund Process

Congress established the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) in 1980. CERCLA is informally called Superfund. It allows the EPA to clean up contaminated sites. It also forces the parties responsible for the contamination to either perform cleanups or reimburse the government for EPA-led cleanup work with hefty fines.

When there is no viable responsible party, Superfund gives EPA the funds and authority to clean up contaminated sites.

Superfund’s goals are to:

  • Protect human health and the environment by cleaning up contaminated sites to federal and/or state standards;
  • Require responsible parties pay for cleanup work;
  • Involve citizens of affected communities in the Superfund process; and
  • Return Superfund sites to productive use.

For more information about Superfund see:

This is Superfund: A Community Guide to EPA’s Superfund Program 

EPA’s details about the Superfund cleanup process

EPA’s information on Butte Superfund

Superfund Terms & The Berkeley Pit


The word root of remediation is remedy, implying the same meaning as ‘cold and flu remedy’ when applied to medicine. In this example, the remedy is given to the injured or sick person to help lessen symptoms, but the remedy does not ‘cure’ the disease. In the case of environmental actions, the remedy is often to remove or contain the contamination. Remedial actions are designed to be protective of human health and the environment first; however, the remedy does not guarantee a return to a natural or ‘before injury’ condition. 

Remedy does not require an area to be returned to a natural condition that is self-sustaining. Rather, remedial actions can prescribe monitoring and maintenance forever. This monitoring is designed as a check-up to ensure that the measures taken to protect human health and the environment are maintained. Examples of remedies in Superfund sites can vary between capping and covering, as in our Butte Hill, to fencing out hazards and requiring that land areas not be utilized, as in nuclear waste sites.

The treatment for the Berkeley Pit is remediation. The Berkeley Pit is federally mandated to be managed to protect human health and the environment forever.


The ultimate goal of restoration is to return something to its original or natural condition. Often that lofty restoration goal is difficult to achieve, therefore, the Superfund statute allows states to replace the injured resource, acquire the equivalent of the injured resource, or to replace the services that the injured resource provided.  One of the intentions of restoration is to create a self-sustaining system that does not require long-term monitoring, maintenance, and management. 

In the case of Silver Bow Creek and the Clark Fork River, restoration includes removal of most of the wastes that were deposited along the riparian areas; floodplain connectivity; and utilization of native plants for revegetation efforts. These efforts allow normal ecological processes to unfold in each area.

Potentially Responsible Party (PRP)

This term is defined in CERCLA or Superfund Law as the company and/or individual owners who are potentially responsible for contamination at a Superfund site. 

The potentially responsible parties for the Berkeley Pit are the Atlantic Richfield Company (AR) and Montana Resources (MR).

Remedial Investigation/Feasibility Study (RI/FS)

These investigations are intended to determine the nature and extent of contamination (i.e., what is the problem?). The RI includes sampling soils, groundwater and streams. Often, both the responsible party and the EPA will conduct remedial investigations.

Once the remedial investigation is complete, and the nature and extent of contamination are understood, the process moves into the feasibility study (i.e., what can be done to fix the problem?). The feasibility study is used to evaluate  various remedy options against nine required criteria:

  1. Overall protection of human health and the environment
  2. Compliance with ARARs (applicable and/or relevant and appropriate requirements). In other words, compliance with laws and regulations.
  3. Long-term effectiveness and permanence
  4. Reduction of toxicity, mobility, and volume
  5. Implementability
  6. Short-term effectiveness
  7. Cost
  8. State Acceptance
  9. Community Acceptance

Typically, both the EPA and the responsible party will conduct feasibility studies. 

In some literature and discussions, the remedial investigation and feasibility studies are lumped together and referred to as one study. Often, the remedial investigation and feasibility studies are conducted concurrently. The RI/FS is completed prior to the Record of Decision. 

Record of Decision (ROD)

This is the legal term for the document created by the involved agencies that explains the clean-up plan and outlines the remedies to be utilized. The ROD summarizes the problem, how the site will be cleaned up, and what remedial action objectives and goals are to be met for the cleanup to be successful.  Prior to the ROD being finalized, the agencies will release a Proposed Plan, which is the opportunity for public comment. The ROD can be changed based on public feedback on the Proposed Plan.

The ROD for sites listed on the NPL is created from information generated during the Remedial Investigation/Feasibility Study (RI/FS). The ROD for the Butte Mine Flooding Operable Unit, which includes the Berkeley Pit, was published in 1994. Download the 1994 Record of Decision

Records of Decision for other Butte/Silver Bow Creek area Superfund Operable Units are available from the EPA Superfund Information Systems.

Consent Decree (CD)

Consent Decree is the legal term for a settlement agreed to by court order. In Superfund, the Consent Decree negotiations between the PRPs and agencies are the final step for settlement. The CD defines the legally-binding cleanup methods, the extent of cleanup, and required  monitoring and reporting. The CD is informed by the remedial investigation, feasibility studies, the Record of Decision, and any ROD modifications completed prior to the CD negotiations.

On August 14, 2002, U.S. District Judge Sam E. Haddon signed the Mine Flooding Consent Decree between the Atlantic Richfield Company (AR), the Montana Resources Group (MR), the U.S. EPA, the State of Montana (DEQ) and the U.S. Department of Justice.

The Consent Decree was released for public review on March 26, 2002, with a May 4 deadline to submit public comments to the federal court. EPA and DEQ reviewed the comments submitted and in late July 2002, the Agencies submitted a report to the federal court recommending that none of the public comments warranted any changes in the Consent Decree. Subsequently, Judge Haddon approved and signed the Consent Decree as originally drafted.

With the Consent Decree lodged in federal court as a legally binding agreement, AR and MR proceeded with plans to build the Horseshoe Bend Water Treatment Plant. The companies are also obligated to provide annual financial statements to document their capability to pay all costs to operate and maintain the facility in perpetuity.

The Consent Decree also requires AR and MR to reimburse EPA and DEQ for past costs and pay for future oversight costs. Other obligations are to enhance the waterfowl protection program at the Berkeley Pit, to establish a groundwater control area surrounding the Berkeley Pit, to fund the Montana Bureau of Mines and Geology to continue the mine flooding monitoring program, and to fund public education (e.g., PITWATCH).

Operable Unit (OU)

Large acreage superfund sites, such as our site, are often broken into smaller management sections, or operable units. The operable units typically are divided by geographic constraints and/or nature of the remedial action needed. In the Butte area, there are several operable units, including the Butte Mine Flooding Operable Unit, Rocker Timber Framing and Treating Plant Operable Unit,  Butte Priority Soils Operable Unit, Streamside Tailings Operable Unit, and West Side Soils Operable Unit. 

The Berkeley Pit is part of the Butte Mine Flooding Operable Unit (BMFOU).

See Butte’s Operable Units on