Applicable or Relevant and Appropriate Requirements (ARARs) - A CERCLA term for any additional cleanup standards (including State environmental requirements and other Federal standards or criteria) which the Environmental Protection Agency or State regulators may impose in selecting the ultimate remedy for a contaminated site.

Appropriated Funds - Funds made available, through Congressional appropriations acts or other laws, which permit the Government to incur obligations and make payments.

Assessment - See "Characterization."

Base Realignment and Closure (BRAC) Account - The account from which Congress requires the Department of Defense to fund environmental restoration efforts at military installations being closed or realigned. The BRAC environmental program, part of an overall BRAC account, funds more than environmental restoration efforts; it also includes environmental compliance and planning related to the closure of military installations.

Bioremediation - Techniques using biological processes to treat contaminated soil or groundwater. Bioremediation can occur either in situ (i.e., on site) or in bioreactors where contaminated media are placed in contact with organisms to degrade the contaminants in a controlled environment. Generally, the technique involves stimulating organisms by adding materials such as nutrients or oxygen to increase the rate of biodegradation.

Budget, Actual - The amount of funding Congress actually appropriates for spending in a given fiscal year.

Budget, Enacted - This is the same as the "actual budget" -- the amount of funding Congress actually enacts through appropriations laws for spending in a given fiscal year.

Budget Request - The amount of funding the President requests the Congress appropriate in a given fiscal year. In formulating the President's budget request, the Administration identifies its major funding themes and crosscutting issues and then makes decisions on agency budget requests, based on Presidential priorities, program performance, and budget constraints.

Budget Target - The amount of a given fiscal year's discretionary funding apportioned to each Federal agency, based on anticipated levels of appropriations. Agencies are expected to adhere to this target in their budget request to the Administration.

Cap - An impermeable earthen or concrete barrier used in environmental restoration. A cap is placed over a contaminated site to prevent further spread of contaminants through groundwater movement.

CERCLA - See "Comprehensive Environmental Response, Compensation, and Liability Act."

Characterization - Site sampling, monitoring, and analysis to determine the extent and nature of releases. Characterization provides the basis for acquiring the necessary technical information to develop, screen, analyze, and select appropriate cleanup techniques.

Civil Penalties - Financial or administrative penalties assessed on an entity for its failure to comply with legal requirements.

Community Environmental Response Facilitation Act (CERFA) - A Federal law which requires the Department of Defense to identify uncontaminated parcels of land or property that can be quickly turned over to communities for economic reuse. CERFA amends CERCLA, allowing 18 months to identify, document, and concur on all uncontaminated parcels of land or property at military installations undergoing closure.

Comprehensive Environmental Response, Compensation and Liability Act - A Federal law, enacted in 1980, that governs the cleanup of hazardous, toxic, and radioactive substances. The Act and its amendments created a trust fund, commonly known as Superfund, to finance the investigation and cleanup of abandoned and uncontrolled hazardous waste sites. Also commonly referred to by its acronym, CERCLA.

Constant Dollars - A budget term which indicates that outyear costs calculated from a set time baseline do not incorporate the time value of money, such as the effects of inflation. When using the current year as the time baseline, this is the same as "current dollars."

Contingency Costs - Costs added to the base cost of performing a specific work scope to cover potential deviations from that work scope.

Cooperative Research and Development Agreement (CRADA) - The mechanism through which the Federal government funds research and development of promising technologies.

Corrective Action - Actions under RCRA or comparable State hazardous waste laws that require a permitted or interim status, hazardous waste management facility to identity and remediate hazardous waste releases from both active and inactive historic activities. Corrective Action Orders can suspend or revoke the authority to operate a treatment, storage, or disposal facility.

Cost-Benefit Analysis - An analysis of the cost of an activity and the benefits (quantitative and/or qualitative) which would accrue from that activity. Used as a decision making tool to determine whether or not to pursue the activity.

Cost-Plus-Award-Fee Contract - A contract which compensates a contractor for costs incurred to perform the contract work scope and also pays both a fixed "base fee" and a fee based on the contractor's performance (an incentive to perform well). Department of Energy management and operating contracts have historically been cost-plus-award-fee contracts.

Cost-Reimbursement Contract - Also known as a cost-plus-no-fee contract, this contract reimburses a contractor for incurred costs; there is no additional fee offered to the contractor.

Crib - A buried structure, often of wood or concrete, filled with aggregate. Its function is to hold or disperse low-level liquids and of solutions for percolation into the ground.

Criminal Liability - The risk of being prosecuted, fined, and jailed for an act which violates a legal requirement.

Current Dollars - A budget term which indicates that outyear costs calculated from the current year do not incorporate the time value of money, such as the effects of inflation.

Deactivation - The removal of hazards from a facility in order to bring it to a safe shutdown, with a focus on minimizing surveillance and maintenance until it can be decontaminated and decommissioned.

Decay (Radioactive) - The spontaneous disintegration of the nucleus of an unstable atom, resulting in the emission of particles and energy.

Decommissioning - The process of removing a facility from operation. This retirement of a facility includes decontamination and/or dismantlement.

Decontamination - The removal of unwanted radioactive material from plants, soil, or equipment by chemical or mechanical processes or other techniques.

Defense Authorization Act - The act through which Congress authorizes appropriations for the Department of Defense and Department of Energy.

Direct Costs - Those costs directly attributable to performing core program objectives, as opposed to indirect costs such as for administrative support and infrastructure maintenance.

Discretionary Funds - The category of U.S. government budget authority from which all Federal facility environmental programs are funded. The President and Congress must decide how to spend this money; and Congress allocates these funds through appropriations acts. All other U.S. government funding is mandatory and includes entitlements (such as Social Security, Medicare, and Food Stamps) and interest on the national debt.

Disposal - Waste emplacement designed to ensure isolation of the waste from the biosphere, with no intention of retrieval for the foreseeable future, and requiring deliberate action to regain access to the waste.

Economic Redevelopment - The economically sustainable reuse/redevelopment of a formerly contaminated Federal facility for other than Federal missions.

Environmental Impact Statements - A study prepared in accordance with National Environmental Policy Act guidelines. These studies evaluate and compare the environmental consequences of a proposed major action, such as the construction of a new facility or other alternatives to that action. The conclusion of an environmental impact statement is usually a record of decision to select the preferred alternative.

Environmental Justice - The principle, as stated in Executive Order 12898, that Federal programs, policies, and activities should not pose disproportionately high and adverse human health or environmental effects on minority and low-income populations.

Environmental Restoration - The cleanup, to accepted levels, of sites contaminated with hazardous substances.

Executive Order - A rule or order having the force of law, issued by the President.

Federal Facilities Compliance Act (FFCA) - A 1992 Federal law which requires the Federal government to develop plans to dispose of Federal facilities' mixed wastes and which waives sovereign immunity from civil penalties for violations of Federal, State, and local hazardous waste laws, and allows the use of administrative enforcement authorities under those laws.

Fissile Material - Material capable of being split by a low-energy neutron. The most common fissile materials are uranium 235 and plutonium 239.

Fixed-Price Contract - A contract for goods or services in which a contractor receives a firm, fixed price to perform the contracted work scope. Because any additions to the work scope result in additional payments to the contractor, these contracts are most suitable for routine or well defined scopes of work.

Force Majeure - Those events which, by their uncontrollable nature, legally nullify and void commitments made. In environmental cleanup, failure of Congress to appropriate sufficient funds to allow the Federal government to meet its legal cleanup commitments is often termed a "force majeure," which would require renegotiation of commitments.

Formerly Used Defense Sites (FUDS) - FUDS are properties formerly owned by, leased to, used by, or otherwise under the operational control of the Department of Defense.

FTE (Full-Time Equivalent) Employment - The basic measure of the levels of U.S. government employment. It is the number of hours worked (or to be worked) divided by the total number of compensable hours in a fiscal year.

Future Land Use - The present day determination of how currently contaminated lands will be used in the future (e.g., residential, recreational, industrial uses). Used to assist in setting in order to decide appropriate cleanup levels.

Geologic Repository - A mined facility for disposal of radioactive waste that uses natural geologic barriers to provide waste containment for geologic time periods (millions of years).

Government Performance and Results Act (GPRA) - A 1993 Federal law which requires government-wide performance measurement, budgeting and results monitoring.

Groundwater - Water occurring beneath the earth's surface that supplies wells and springs.

Half-Life - The time it takes for one-half of any given number of unstable atoms to decay. Each isotope has its own characteristic half-life. They range from small fractions of a second to billions of years (the half-life for plutonium is 24,000 years).

Hazardous Waste - As defined in RCRA, a solid waste, or combination of solid wastes, that because of its quantity, concentration, or physical, chemical, or infectious characteristics, may cause or significantly contribute to an increase in mortalit y or an increase in serious, irreversible, or incapacitating reversible illness or pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, or disposed of, or otherwise managed.

Health Physics - The science of radiation protection.

Highly Enriched Uranium (HEU) - Uranium with more than 20 percent of the uranium 235 isotope, used for making nuclear weapons and also as fuel for some isotope-production, research, and power reactors. Weapons-grade uranium is a subset of this gr oup.

High-Level Waste - Material generated by chemical reprocessing of spent fuel and irradiated targets. High-level waste contains highly radioactive, short-lived fission products, hazardous chemicals, and toxic heavy metals. High-level waste is usual ly found in the form of a liquid, a solid saltcake, a sludge, or a dry powdery calcine.

Impermeable Barrier - A durable material (usually clay or a geotextile) which serves as a barrier to contaminant and water movement.

Indirect Costs - Costs not related to achieving core program objectives; it includes such sitewide costs as administrative support, utilities, infrastructure maintenance, and security.

Injunctive Relief - The ability to order an entity to refrain from doing a specified act. In Federal cleanup, State and local regulators have the ability to seek injunctive relief against a Federal agency, ordering the agency to stop activities which violate environmental laws.

Innovative Technology - A technology considered promising but not yet demonstrated sufficiently to be considered proven and thus widely used for cleanups.

In Situ Remediation - Any environmental remediation technique which is applied at the site of the contamination, rather than moving the contaminants to a separate treatment facility.

Interagency Agreements (IAGs) - Legally binding agreements between regulatory agencies and regulated parties setting standards and schedules (marked by milestone activities) for compliance with environmental laws. CERCLA requires IAGs for all sites on the National Priorities List.

Interim Action - Removal actions and interim remedial actions that accelerate the reduction of risk to human health and the environment. Interim actions remove or stabilize contaminant sources and thereby reduce or eliminate immediate risks until final remediation.

Ionizing Radiation - Radiation that is capable of breaking apart molecules or atoms. The splitting or decay of unstable atoms typically emits ionizing radiation.

Isotopes - Different forms of the same chemical element that differ only by the number of neutrons in their nucleus. Most elements have more than one naturally occurring isotope. Many more isotopes have been produced in reactors and scientific l aboratories.

Leaching - The passing of a soluble constituent or contaminant through a permeable substance, such as soil.

Legacy Waste - Waste products generated during the Department of Energy's production of nuclear weapons from 1943 until 1989. The Department's Environmental Management Program is responsible for cleaning up, treating and disposing of this legacy w aste, much of which has simply been stored for the past 50 years.

Low-Enriched Uranium - Uranium that has been enriched until it consists of about 3 percent uranium 235 and 97 percent uranium 238. Used as nuclear reactor fuel.

Low-Level Waste - A catchall term for any radioactive waste that is not spent fuel, high-level, or transuranic waste.

"Make or Buy" - A decision as to whether to produce (make) or to purchase (buy) goods or services, based on an analysis of costs and long-term strategic objectives.

Management and Operating (M&O) Contractor - Contractors hired by the Department of Energy to manage and operate its sites, including research and development laboratories and nuclear weapons production facilities.

Milestones - See "Interagency Agreements."

Mine Tailings - The materials left over from separating a recoverable resource from its ore.

Mixed Waste - Waste that contains both chemically hazardous and radioactive materials.

Municipal Waste - Waste generated from typical residential and light industrial operations.

Munitions - Any type of explosive military ammunition (as in grenades or bombs).

National Environmental Policy Act (NEPA) - A Federal law, enacted in 1970, that requires the Federal government to consider the environmental impacts of, and alternatives to, major proposed actions in its decision-making processes. Commonly referred to by its acronym, NEPA.

National Performance Review - A March 1993 Clinton Administration initiative to review and recommend changes to the Federal government, to create a more effective, efficient and responsive government that works better and costs less.

National Priorities List (NPL) - A listing of the nation's worst hazardous waste sites requiring cleanup, as established by CERCLA.

Natural Resource Damage - Damage to ecological resources from environmental contamination. The Federal government has not completed many assessments to quantify the impacts on and risks to these ecological resources, since Federal funding to date has been primarily focused on human health and safety rather than ecological risks.

Natural Uranium - Uranium that has not been through the enrichment process. It is made of 99.3 percent uranium 238 and 0.7 percent uranium 235.

Non-Legacy Waste - As distinguished from legacy waste, those waste products generated from the Department of Energy's operations after nuclear weapons production stopped in 1989.

Nonproliferation - Efforts to prevent or slow the spread of nuclear weapons and the materials and technologies used to produce them.

Nuclear Weapons Complex - The chain of foundries, uranium enrichment plants, reactors, chemical separation plants, factories, laboratories, assembly plants, and test sites that produced nuclear weapons. There are 16 major facilities in the U.S. nuclear weapons complex that are located in 12 states.

Obligation (Funding) - A binding agreement that will result in Government spending either immediately or in the future. Budgetary resources must be available before obligations can be legally incurred.

Omnibus Budget Reconciliation Act (OBRA) - A Federal law, passed in 1993, which caps Federal discretionary spending through 1998.

Operable Unit - A discrete area consisting of a single to many potential release sites, grouped together for purposes of assessment and cleanup. The primary criteria for placement of release sites into an operable unit include geographic proximity, similarity of waste characteristics and site type, and the possibility for economies of scale.

Ordnance - Military weapons of all kinds, including associated equipment and ammunition.

Overhead Costs - Those costs, such as administrative support and infrastructure maintenance, not directly chargeable to a particular work element.

Phytoremediation - The emerging science of planting specific crops which draw into their root systems comparatively large quantities of contaminants from soils or water and, over time and successive plantings, can remediate the environmental impact of contaminants.

Polychlorinated Biphenyls (PCBs) - A group of commercially produced organic chemicals used extensively since the 1940s in industrial applications at Federal facilities. Most notably, PCBs are found in gaskets, large electrical transformers, and capacitors. PCBs have been proven to be toxic to both humans and laboratory animals.

Plutonium - A manmade fissile element. Pure plutonium is a silvery metal that is heavier than lead. Material rich in the Plutonium 239 isotope is preferred for manufacturing nuclear weapons, although any plutonium can be used. Plutonium 239 has a half-life of 24,000 years.

Potential Release Site - A site from which there is a potential for release of contaminants to the environment -- for example, a hazardous waste storage tank.

Preliminary Assessments - A phase of the CERCLA remediation process used to determine whether a site has contaminated, or has the potential to contaminate, the environment.

Presumptive Remedy - A remedial action alternative selected based on the remedy's successful use on similar past cleanups, in order to expedite the CERCLA remedial investigation process.

Privatization - The conversion of a government-performed activity to private nongovernment performance, either to eliminate an activity which is not a valid government function or to cut the cost or improve the efficiency of performing the activity by introducing competition.

Procurement - The process through which the Federal government contracts for goods or services from outside sources.

Pump and Treat - Groundwater remediation technique involving the extraction of contaminated groundwater from the subsurface to remove contaminants and subsequent return of the treated water to its source.

Radioactive Waste - Solid, liquid, or gaseous material resulting from weapons production that contains radionuclides in excess of threshold quantities. This may include high level, low level, or transuranic wastes, spent fuels, or highly enriched uranium.

Radionuclide - A radioactive species of an atom. For example, tritium, strontium 90, and uranium 235 are all radionuclides.

RCRA - See "Resource Conservation and Recovery Act."

Record of Decision (ROD) - The CERCLA document which selects the remedial action to be implemented at a site after the Remedial Investigation and Feasibility Study is completed.

Reinventing Government (REGO) - A continuation of Federal agency initiatives begun under the National Performance Review.

Remedial Investigation and Feasibility Study (RI/FS) - A phase of the CERCLA remediation process to identify the nature and extent of contamination at a site, and to evaluate remedial action alternatives to correct or prevent the migration of those contaminants from that site.

Remediation - The process of applying a chosen technique or process to correct an environmental problem. This process may either stabilize, contain, entomb, neutralize, or destroy the hazardous contaminant.

Resource Conservation and Recovery Act - A Federal law enacted in 1976 to address the treatment, storage, and disposal of hazardous waste.

Restoration - See "Environmental Restoration"

Restoration Advisory Board (RAB) - The mechanism through which the Department of Defense involves its local stakeholders in Federal cleanup decisions.

Risk Assessment - A methodology to evaluate the extent of human exposure to environmental contaminants with potential health effects. Risk assessments may be quantitative (calculated from exposure to a contaminant and its known chemical characteristics) or qualitative (taking into account cultural, social, and economic factors, including environmental justice considerations).

Rule Making - The process through which a Federal agency promulgates rules or regulations to implement laws passed by Congress. The Code of Federal Regulations publishes all such rules.

Sequestration of Funds - The cancellation of discretionary funds which could be appropriated. This occurs to keep spending within preauthorized limits.

Site Characterization - The technical process used to evaluate the nature and extent of environmental contamination. This process is necessary for designing remediation measures and monitoring their effectiveness.

Sovereign Immunity - The Constitutional principle that the Federal government is not required to comply with any laws unless Congress specifically waives immunity to that law. The Federal Facilities Compliance Act amended RCRA's waiver of sovereign immunity, to hold Federal agencies liable for civil penalties and Federal officials liable for criminal sanctions.

Spent Nuclear Fuel - Fuel elements and other materials (such as uranium 238 "targets" used to produce plutonium) that have been irradiated in a nuclear reactor.

Stakeholders - Individuals, or groups of individuals, interested in or affected by agency operations or cleanup activities.

Superfund - See "Comprehensive Environmental Response, Compensation and Liability Act."

Support Services - Those discrete services, ranging from routine tasks (such as clerical support and moving services) to highly specialized technical tasks, which the Department of Energy contracts for, rather than hiring permanent Federal employees.

Toxicity - The ability of a substance to cause damage to living tissue; impairment of the central nervous system; severe illness; or (in extreme cases) death when ingested, inhaled, or absorbed by the skin. Amounts required to produce these results vary widely with the nature of the substances and the time of exposure.

Transport Mechanisms - The various ways contaminants can spread, e.g., through air, groundwater, etc.

Transuranic Waste - Radioactive waste contaminated with uranium 233 or elements beyond uranium on the periodic table and existing in concentrations of more than 1 ten-millionth of a curie per gram of waste. These isotopes have half-lives of over 20 years and are all manmade.

Treatment Facility - A facility in which activities are performed that alter the chemical or physical nature of a hazardous waste to reduce its toxicity, volume, mobility, or render it amenable for transport, storage, or disposal.

Uranium - The basic material for nuclear technology, it is a slightly radioactive, naturally occurring heavy metal that is more dense than lead.

Vitrification - A process that stabilizes nuclear waste by mixing it with molten glass. The glass is poured into metal canisters, where it hardens into logs. The Department of Energy has built plants for vitrifying high-level-waste at West Valley, New York, and the Savannah River Site.

Waste Isolation Pilot Plant (WIPP) - A geologic repository intended to provide permanent disposal for transuranic wastes, deep underground (2,150 feet) in a salt bed near Carlsbad, New Mexico.

Watershed - The land mass over which all surface water runs into a particular body of water.