Administrative Order (AO): A legal and enforceable agreement between EPA and the parties potentially responsible for site contamination. Under the terms of the Order, the potentially responsible parties agree to perform or pay for site studies or cleanups. It also describes the oversight rules, responsibilities and enforcement options that the government may exercise in the event of non-compliance by potentially responsible parties. This Order is signed by PRPs and the government; it does not require approval by a judge.
Air Stripping: A treatment system that removes, or "strips," volatile organic compounds from contaminated groundwater or surface water by forcing an airstream through the water and causing the compounds to evaporate.
Aquifer: An underground zone of water saturation within a formation composed of materials such as sand, soil, gravel, or bedrock that can store and supply groundwater to wells and springs. Most aquifers used in the United States are within a thousand feet of the earth’s surface.
CERCLIS: The abbreviation of the CERCLA Information System, EPA’s comprehensive data base and management system that inventories and tracks releases addressed or needing to be addressed by the Superfund program. CERCLIS contains the official inventory of CERCLA sites and supports EPA’s site planning and tracking functions. Inclusion of a specific site or area in the CERCLIS database does not represent a determination of any party’s liability.
Comment Period: A time period during which the public can review and comment on various documents and EPA actions. For example, a comment period is provided when EPA proposes to add sites to the National Priorities List. Also, a minimum three-week comment period is held to allow community members to review and comment on a draft feasibility study.
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA): A federal law passed in 1980 and modified in 1986 by the Superfund Amendments and Reauthorization Act. The acts created a special tax that goes into a Trust Fund, commonly known as Superfund, to investigate and clean up abandoned or uncontrolled hazardous waste sites. Under the program, EPA can either:
- Pay for site cleanup when parties responsible for the contamination cannot be located or are unwilling or unable to perform the work; or,
- Take legal action to force parties responsible for site contamination to clean up the site or pay back the federal government for the cost of the cleanup.
Consent Decree (CD): A legal document approved and issued by a judge, that formalizes and agreement reached between EPA and potentially responsible parties (PRPs) where PRPs will perform all or part of a Superfund site cleanup. The consent decree describes actions that PRPs are required to perform and is subject to a public comment period.
Cooperative Agreement: A contract between EPA and the state wherein a state agrees to manage or monitor certain site cleanup responsibilities and other activities on a cost-sharing basis.
Explanation of Significant Differences (ESD): A document issued by EPA after adoption of the ROD which explains differences in the remedial action that significantly change but do not fundamentally alter the remedy selected in the ROD with respect to scope, performance, or cost.
Feasibility Study (FS): A study undertaken by the lead agency to develop and evaluate options for remedial action. The FS emphasizes data analysis and is generally performed concurrently and in an interactive fashion with the remedial investigation (RI), using data gathered during the RI. The RI data are used to define the objectives of the response action, to develop remedial action alternatives, and to undertake an initial screening and detailed analysis of the alternatives. The term also refers to a report that describes the results of the study.
Federal Facility Agreement (FFA): A written agreement between EPA and a federal agency that has the lead for site cleanup activities (e.g. the Department of Defense), that sets forth the roles and responsibilities of the agencies for performing and overseeing the activities. States are often parties to these agreements.
Groundwater: Water found beneath the earth’s surface that fills pores and voids between materials such as sand, soil, gravel or bedrock. In aquifers, groundwater occurs in sufficient quantities that it can be used for drinking water, irrigation and other purposes.
Groundwater Management Zone (GMZ): Area where contaminated groundwater exists, which is monitored under a state groundwater management permit until the contamination is abated by natural attenuation.
Hazard Ranking System (HRS): A scoring system used to evaluate potential relative risks to public health and the environment form releases or threatened releases of hazardous substances. EPA and states use the HRS to calculate a site score, from) to 100, based on the actual or potential release of hazardous substances from a site through air, surface water, or groundwater to affect people. This score is the primary factor used to decide if a hazardous waste site should be placed on the National Priorities List.
Incineration: Burning of certain types of solid, liquid, or gaseous materials under controlled conditions to destroy hazardous wastes.
Installation Restoration Program (IRP): The specially funded program established in 1978 under which the Department of Defense has been identifying and evaluating its hazardous waste sites and controlling the migration of hazardous contaminants from those sites.
Management of Migration (MOM): Actions that are taken to minimize and mitigate the migration of hazardous substances or pollutants or contaminants and the effects of such migration. Measures may include, but are not limited to, management of a plume of contamination, restoration of a drinking water aquifer, or surface water restoration.
Maximum Contaminant Levels (MCLs): Drinking water standards that are enforceable under the federal Safe Drinking Water Act.
Monitoring Wells: Special wells drilled at specific locations on or off a hazardous waste site where groundwater can be sampled at selected depths and studied to determine such things as the direction in which groundwater flows and the types and amounts of contaminants present.
National Oil and Hazardous Substances Contingency Plan (NCP): The federal regulation that guides the Superfund program.
National Priorities List (NPL): EPA’s list of the most serious uncontrolled or abandoned hazardous waste sites identified for possible long-term remedial response using money from the Trust Fund. The list is based primarily on the score that a site receives on the Hazardous Ranking System (HRS). EPA is required to update the NPL at least once a year.
Notice Letter: A general notice letter notifies the parties potentially responsible for site contamination of their possible liability. A special notice letter begins a 60-day formal period of negotiation during which EPA is not allowed to start work at a site or initiate enforcement actions against potentially responsible parties, although EPA may undertake certain investigatory and planning activities. The 60-day period may be extended if EPA receives a good faith offer within that period.
Polychlorinated biphenyls (PCBs): A group of toxic chemicals used for a variety of purposes including electrical applications, carbonless copy paper, adhesives, hydraulic fluids, microscope emersion oils, and caulking compounds. PCBs are also produced in certain combustion processes. PCBs are extremely persistent in the environment because they are very stable, non-reactive, and highly heat resistant. Burning them produces even more toxins. Chronic exposure to PCBs is believed to cause liver damage. It is also known to bioaccumulate in fatty tissues. PCB use and sale was banned in 1979 with the passage of the Toxic Substances Control Act.
Potentially Responsible Party (PRP): Parties, including owners, who may have contributed to the contamination at a Superfund site and may be liable for costs of response actions. Parties are considered PRPs until they admit liability or a court makes a determination of liability. This means that PRPs may sign a consent decree or administrative order on consent to participate in site cleanup activity without admitting liability.
Preliminary Assessment (PA): The review of existing information and an offsite reconnaissance, if appropriate, to determine if a release may require additional investigation or action. A PA may include an on-site reconnaissance, if appropriate.
Quality Assurance/Quality Control (QA/QC): A system of procedures, checks, audits, and corrective actions used to ensure that fieldwork and laboratory analysis during the investigation and cleanup of Superfund sites meet established standards.
Record of Decision (ROD): A public document that explains which cleanup alternative(s) will be used at National Priorities List sites where the Trust Fund pays for the cleanup. The Record of Decision is based on information and technical analysis generated during the remedial investigation/feasibility study and consideration of public comments and community concerns.
Remedial Action (RA): The actual construction or implementation phase that follows the remedial design of the selected cleanup alternative at a site on the National Priorities List.
Remedial Design (RD): An engineering phase that follows the Record of Decision when technical drawings and specifications are developed for the subsequent remedial action at a site on the National Priorities List.
Remedial Investigation (RI): The process undertaken by the lead agency to determine the nature and extent of the problem presented by the release. The RI emphasizes data collectionand site characterization, and is generally performed concurrently and in an interactive fashion with the feasibility study. The RI includes sampling and monitoring, as necessary, and includes the gathering of sufficient information to determine the necessity for remedial action and to support the evaluation of remedial alternatives.
Remediation: Cleanup method at a hazardous waste site.
Resource Conservation and Recovery Act (RCRA): RCRA means the federal Solid Waste Disposal Act as amended by the Resource Conservation and Recovery Act of 1976. Established as a regulatory system under which states track hazardous wastes from the time of generation to disposal.
Risk Assessment: An evaluation performed as part of the remedial investigation to assess conditions at a Superfund site and determine the risk posed to public health and/or the environment.
Site Inspection (SI): An on-site investigation to determine whether there is a release or potential release and the nature of the associated threats. The purpose is to augment the data collected in the preliminary assessment and to generate, if necessary, sampling and other field data to determine if further action or investigation is appropriate.
Source Control (SC): The construction or installation and start-up of those actions necessary to prevent the continued release of hazardous substances or pollutants or contaminants.
Superfund: The common name used for the Comprehensive Environmental Response, Compensation, and Liability Act, also referred to as the Trust Fund.
Superfund Amendments and Reauthorization Act (SARA): Modifications to CERCLA enacted on October 17, 1986.
Surface Waters: Bodies of water that are above ground, such as rivers, lakes, and streams.
Technical Assistance Grant (TAG): A grant (up to $50,000) available to community groups for the purpose of hiring technical advisors to help citizens understand and interpret site-related technical information.
Trust Fund: A fund set up under CERCLA to help pay for cleanup of hazardous waste sites and to take legal action to force those responsible for the sites to clean them up; also referred to as Superfund.
Volatile Organic Compound (VOC): VOCs are made as secondary petrochemicals. They include light alcohols, acetone, trichloroethylene, perchloroethylene, dichloroethylene, benzene, vinyl chloride, toluene, and methylene chloride. These potentially toxic chemicals are used a solvents, degreasers, paints, thinners, and fuels. Because of their volatile nature, they readily evaporate into the air, increasing the potential exposure to humans. Due to their low water solubility, environmental persistence, and widespread industrial use, they are commonly found in soil and groundwater at waste sites.