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Glossary of Terms

These definitions are provided to assist public understanding of technical terms used on this NASA cleanup Website. They are not intended to serve as legal definitions for any words or phrases included here.

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Action Memorandum: The document that describes a selected removal action alternative (if needed) for an area of a CERCLA site—or as part of the CERCLA cleanup process and explains the rationale for the selection. The Action Memorandum includes responses to public and regulatory agencies’ comments and concerns raised during the public comment period. It becomes part of the Administrative Record for that project. See Removal Action 

Activated Carbon: Oxygen is used to open up millions of small pores on a granular charcoal (carbon) product, which increases its ability to adsorb other chemicals.

Adjudicated Water Basin: A water basin where a court-directed process has determined how much groundwater can rightfully be extracted by each municipal landowner or water purveyor. The court appoints so-called “watermasters” to oversee the court judgment. The Raymond Basin Management Board is the watermaster for the area in which the JPL is located, and a nine-member Board elected from area water purveyors and water districts is the appointed watermaster for the larger San Gabriel Basin.

Administrative Record: A file containing everything (reports, transcripts, etc.) the lead agency relied upon in reaching its decision to select a CERCLA remedial action or removal action for a site. The entire Administrative Record can be found on the water cleanup Website at and at the NASA information repositories located at the Pasadena, Altadena, and La Cañada Flintridge public libraries.

Air Stripping: A treatment system that removes or "strips" volatile organic compounds from contaminated groundwater or surface water by forcing an air stream through the water causing the compounds to evaporate.

Aquifer: A sand, gravel or rock formation capable of storing or conveying water below the surface of the land.

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Boletin Bilingüe: The Spanish phrase for a newsletter published by NASA in English and Spanish with the purpose of updating the public, including Spanish-speaking residents, on NASA’s groundwater cleanup project at JPL.

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California Department of Public Health (DPH): A newly named state agency that recently reorganized elements of the former California Department of Health Services. The DPH provides information about public health services, programs, health statistics, health licensure and more.

California Environmental Protection Agency (Cal/EPA): The State agency whose mission is to restore, protect and enhance the environment, to ensure public health, environmental quality and economic vitality. Under its umbrella are included agencies such as the Department of Toxic Substances Control (DTSC).

California Institute of Technology (Caltech): Located in Pasadena, California, Caltech is an academic and research institution focused on math, science and engineering. JPL is an operating division of Caltech, which manages JPL for NASA.

Carbon Filtration: A water treatment system that forces contaminated water through tanks where activated carbon (see above) is present. Unwanted chemicals bond to the porous carbon, leaving clean water to pass through the filter. The used carbon filter is then properly disposed.

Chemicals of Concern: Chemicals in soil and groundwater that are targeted for treatment and/or removal. At the NASA JPL CERCLA site, the primary chemicals of concern include volatile organic compounds (VOCs) and perchlorate. These compounds have been found in soil beneath JPL and in groundwater beneath JPL and beneath adjacent areas.

City of Pasadena: Pasadena is a community rich in diversity, historic architecture, arts, entertainment, dining, shopping and economic opportunities.

Cleanup: An informal term broadly used to describe various activities taken to deal with a release, threatened release, or presence of a hazardous substance or substances that could affect public health and/or the environment.

Code of Federal Regulations (CFR): A collection or systematic arrangement of regulations published in the Federal Register by the executive departments and agencies of the federal government and that implement statutes.

Community Interviews: One-on-one meetings or small group interviews conducted with area residents or various stakeholders to gather information (i.e., perceptions, concerns, questions, information needs and preferences for communication). NASA’s community interviews about the groundwater cleanup process at the JPL CERCLA site were used as a basis to update NASA’s Community Involvement Plan.

Community Information Session: An event (or meeting) where community members are invited to learn more about various aspects of NASA’s cleanup process and have the opportunity to meet one-on-one with NASA staff and experts to ask questions or voice concerns. Information is usually presented in a series of displays that community members may peruse, depending on their interests.

Community Involvement: An important part of the CERCLA program used to ensure that members of the public have ways to be meaningfully informed about investigation and cleanup activities and also have opportunities to have input into the decision-making process.

Community Involvement Plan (CIP – formerly Community Relations Plan): Based on community interviews and the cleanup program’s analysis, this document outlines community concerns and expectations for the remediation of a CERCLA site. This document describes how the lead agency will address public information needs and provide opportunities for community involvement in the decision-making process.

Comprehensive Environmental Response, Compensation and Liability Act (CERCLA): The 1980 law commonly known as Superfund, which authorizes the US EPA to respond to releases, or threatened releases, of hazardous substances that may endanger public health, welfare, or the environment. CERCLA also enables EPA to force parties responsible for environmental contamination to clean it up or to reimburse the Superfund for response or remediation costs incurred by EPA. The Superfund Amendments and Reauthorization Act (SARA) of 1986 revised various sections of CERCLA, extended the taxing authority for the Superfund, and created a free-standing law, SARA Title III, also known as the Emergency Planning and Community Right-to-Know Act (EPCRA).

Contaminant: According to the federal Agency for Toxic Substances and Disease Registry (ATSDR), a contaminant is a substance that is either present in an environment where it does not belong or is present at levels that might cause harmful (adverse) health effects.

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Department of Toxic Substances Control (DTSC): Part of the California Environmental Protection Agency (Cal/EPA), the Department of Toxic Substances Control (DTSC) regulates hazardous waste and cleanup of existing contamination, and looks for ways to reduce the hazardous waste produced in California. Approximately 1,000 scientists, engineers, and specialized support staff make sure that companies and individuals handle, transport, store, treat, dispose of, and clean up hazardous wastes appropriately.

Delisting: When all appropriate response actions are completed and no further activity is required to protect human health or the environment at a CERCLA site, the site, or a portion of the site (e.g., an Operable Unit), may be removed (de-listed) from the National Priorities List.

Discretionary Activities: Additional methods for CERCLA sites – beyond what is required by U.S. EPA guidance – that NASA uses to inform the public and involve the community in the JPL cleanup process.

Drinking Water Standards: A set of legally enforceable regulations that apply to public water systems to protect public health by limiting the levels of contaminants in drinking water.

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Engineering Evaluation/Cost Assessment (EE/CA): If a lead agency determines that a removal activity is appropriate at a CERCLA site and a planning period of at least six months is available for planning the activity, an EE/CA is conducted to identify the objectives of the removal and evaluate various alternatives based on cost, effectiveness, and the ability to implement the EE/CA.

Environment: As used in CERCLA, the environment includes any surface water, drinking water supply, groundwater, land, surface or air within the U.S. or under U.S. jurisdiction.

Expanded Site Inspection (ESI): A step in the CERCLA process following the Preliminary Site Investigation – sometimes necessary to provide more detailed information to use in the Hazard Ranking System (HRS).

Expanded Treatability Study: Larger in scope than a pilot test, this field study further demonstrates the effectiveness of the specific technology selected. An Expanded Treatability Study was conducted for the cleanup of on-facility groundwater at JPL.

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Feasibility Study (FS): A step that follows the Remedial Investigation in the CERCLA process. The FS develops alternatives for remediating a site, evaluates them and selects a preferred alternative.

Five Year Review – In 2012, NASA, in conjunction with the U.S. EPA, conducted its first “Five-Year Review” of the groundwater cleanup project. The EPA concurred with NASA that the interim remedies in place – the three NASA-funded treatment systems and NASA’s extensive groundwater monitoring program – “are protective of human health and the environment in the short term.” The EPA added in its concurrence letter that, “Long term protection of human health and the environment at this site will be achieved when the final Record of Decision(s) for groundwater are issued and implemented.”

Fluidized Bed Reactor: A treatment system that uses naturally occurring microorganisms to break down groundwater contaminants. A biological fluidized bed reactor is being used by NASA at JPL to remove perchlorate from groundwater beneath the Laboratory as part of the OU-1 Source Area Treatment System. The system uses vertical tanks containing a bed of granular activated carbon upon which naturally occurring bacteria can grow. Added nutrients make naturally occurring bacteria multiply. As groundwater flows upward and through the bed, the bacteria destroy the perchlorate.

Frequently Asked Questions (FAQ): NASA has compiled a list of questions and answers that may be asked by the public about the JPL CERCLA process. The FAQs can be found on the website and in the information repository.

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GPM: Gallons per minute is one of the units commonly used to measure water flow. (Cubic feet per second [CFS] is another.)

Groundwater: Water found beneath the earth's surface in pores in sand, soil, or gravel

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Hazard Ranking System (HRS): A scoring system that EPA uses to decide if a site poses potential risks to public health and the environment from releases or threatened releases of hazardous substances. The HRS is the key determinant as to whether a site should be placed on the National Priorities List and be regulated by CERCLA.

Hazardous Substance: Specifically defined by statue (in CERLCA) – material that poses a threat to public health and/or the environment. Typical hazardous substances are materials that are toxic, corrosive, ignitable, explosive, or chemically reactive.

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Information Repository: A file available to the public that contains current information, technical reports, and reference documents regarding a CERCLA site. The information repository is usually located in a public building that is convenient for local residents - such as a public school, city hall, or library.

Institutional Controls: Legal, non-engineering methods such as zoning, deed restrictions or other barriers to prevent use or access to a site or part of a site after the remedy has been implemented.

Ion Exchange Treatment System: A treatment system – used by NASA as part of the groundwater cleanup effort at and near JPL – that is designed to remove perchlorate from groundwater. The system runs groundwater through tanks filled with resin beads. When perchlorate touches the beads, perchlorate is exchanged with chloride and is extracted from water.

Interim Record of Decision: A legal, public document that explains a proposed action to implement a remedy at a CERCLA site that also allows additional studies to be performed prior to selection of the final remedy for the entire site.

In-situ Bioremediation: Any process performed that uses microorganisms (bacteria) to remove unwanted chemicals from their original or natural location in the environment.

Isotopic Analysis: As applied to the cleanup at JPL, the use of recently developed technologies to examine and differentiate the isotopic composition of perchlorate in groundwater. There can be measurable differences in the isotopic signatures of different perchlorate sources based on their origin. Isotopic analysis has been used to distinguish between natural and man-made perchlorate and may help distinguish among different man-made perchlorate sources and may enhance the understanding of perchlorate transport and fate.

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Lead Agency: The government agency designated in a Federal Facilities Agreement under the CERCLA and SARA laws that is responsible for the preparation and implementation of a remedial action plan. Also: the agency that has the lead to prepare an environmental analysis of a proposed project.

Lincoln Avenue Water Company (LAWC): Located at 564 West Harriet, Altadena, California 91001, the Lincoln Avenue Water Company is the oldest local water company in the Pasadena area and serves west Altadena. The LAWC operates a NASA-funded groundwater treatment plant that removes volatile organic compounds and perchlorate from drinking water at two of its operational wells.

Liquid-phase Granular Activated Carbon: A treatment system – used by NASA as part of the groundwater cleanup effort at and near JPL – in which particles of volatile organic compounds are attracted to the surface of activated carbon and removed from water.

Los Angeles Regional Water Quality Control Board (LARWQCB): The LARWQCB protects ground and surface water quality in the Los Angeles region, including the coastal watersheds of Los Angeles and Ventura counties, along with very small portions of Kern and Santa Barbara counties. The Los Angeles Regional Board is one of nine regional boards statewide. These boards are part of the California Environmental Protection Agency (CAL/EPA).

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Monitoring Wells: Wells drilled at specific locations where groundwater can be routinely sampled at selected depths to determine groundwater flow patterns, and types and extent of contamination present.

Multicultural Stakeholders: The term multicultural recognizes the broad scope of dimensions of race, ethnicity, language, sexual orientation, gender, age, disability, class status, education, religious/spiritual orientation, and other cultural dimensions. In these pages it means a recognition that a multiplicity of these dimensions exists and are valued.

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National Oil and Hazardous Substances Pollution Contingency Plan (National Contingency Plan, NCP): The Federal regulation that guides the CERCLA program.

National Priorities List (NPL): EPA's list of highest priority sites for investigation and cleanup that become regulated by CERCLA. The List is based primarily on the score it receives on the Hazard Ranking System (HRS). EPA is required to update the NPL at least once a year.

Notice of Intent: The published notice of a lead agency’s intent to de-list a site from the NPL. Usually announced in a local newspaper.

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Operable Unit (OU): A site listed on the NPL may be divided into separate areas for purposes of site investigation and cleanup. OUs help facilitate addressing specific issues at the site such as geographic areas within the site, contaminants, or environmental conditions. NASA has divided the JPL CERCLA site into three Operable Units: OU-1 is groundwater on-site beneath the JPL facility; OU-2 is soil on-site at JPL; and OU-3 refers to groundwater beneath lands adjacent to JPL, that is, groundwater off-site.

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Packed Bed Reactor: A water treatment system for removing perchlorate from groundwater.

Pasadena Water & Power: Pasadena Water and Power (PWP), originally called the Pasadena Municipal Light and Power Department, was initiated by City Ordinance in 1906. Today, PWP provides electricity to some 57,000 customers within Pasadena. It also delivers water to 37,000 households and businesses in Pasadena and adjacent communities in the San Gabriel Valley.

Perchlorate: Perchlorate is both a naturally occurring and manmade chemical. Naturally occurring perchlorate, for example, is found in nitrate fertilizer deposits from Chile. Perchlorate, ClO4-, is used in flares, fertilizers and fireworks in addition to its use as an oxidizer in rocket propellant.

Public Comment Period: A time period during which the public can review CERCLA-related documents and proposed activities and submit written and/or verbal comments that become part of the official transcript.

Preliminary Assessment: An initial step in the CERCLA process to collect and review available information about a site. EPA uses this information to determine whether the site requires further study and, if needed, a Site Inspection is undertaken.

Proposed Plan: An outline of the remedial alternatives evaluated for a site (or Operable Unit), including reasons for selecting the preferred alternative. When a Proposed Plan is issued, a 30-day public comment period follows, during which time the public may submit comments in writing or may voice concerns at a public meeting.

Public Meeting: A forum where the public hears information on specific proposed actions or related activities and has an opportunity to ask questions and provide formal comments and testimony on proposed actions.

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The Raymond Basin Management Board (RBMB): The RBMB is responsible for managing
the current and future quality and quantity of water resources for the benefit of its members and the communities they serve. The Raymond Basin covers approximately 40 square miles. It is bounded on the north by the San Gabriel Mountains, on the south and east by the San Gabriel Valley and on the west by the San Rafael Hills. Because of its natural formations and barriers, the Raymond Basin is replenished by surface water flows from the San Gabriel Mountains, including the Arroyo Seco, Eaton Wash and Santa Anita Wash.

Record of Decision (ROD): A legal, public document that explains the final cleanup alternative to be used for a particular Operable Unit or the overall site. The ROD includes a responsiveness summary, in which the lead agency (NASA) responds to public comments received during the public comment period on a Proposed Plan. The public is informed of the availability of the final Record of Decision through publication of a notice in the local newspaper.

Regional Water Quality Control Board – Los Angeles Region (RWQCB):

One of nine Regional Boards statewide belonging to the California Environmental Protection Agency (CAL/EPA) protecting ground and surface water quality in the Los Angeles Region, including the coastal watersheds of Los Angeles and Ventura Counties, along with very small portions of Kern and Santa Barbara Counties. See Los Angeles Regional Water Quality Control Board, above.

Remedial Action (RA): A step in the CERCLA process following the Remedial Design, in which the remedy is implemented.

Remedial Design: An engineering phase in the CERCLA process that follows the Record of Decision when technical drawings and specifications for the site remedy are developed. Necessary permitting activities may also occur during this time period.

Remedial Investigation (RI): A step in the CERCLA process to gather data necessary to fully determine the nature and extent of contamination at a CERCLA site.

Remedial Project Manager: The lead agency official responsible for overseeing remedial response activities.

Remedial Response: A long-term action that stops or substantially reduces a release or threatened release of one or more hazardous substances.

Remediation: Actions taken to deal with a release or threatened release of hazardous substances that could affect public health, welfare or the environment. The term "remediation" is often used broadly as “cleanup” to describe various CERCLA response actions, such as a Removal Action or a Remedial Action.

Removal Action: An immediate action taken to address a release or threatened release of hazardous substances.

Response Action: A short-term Removal Action (see above) or a long-term remedial response.

Responsiveness Summary: The collection of oral and/or written public comments received by the lead agency (NASA) during a public comment period on key documents, and NASA's responses to those comments.

Reverse Osmosis: A water treatment process where unwanted chemicals may be extracted by forcing the water through a semi-permeable membrane under high pressure.

Risk Assessment: A study conducted as part of the remedial investigation that assesses conditions at a CERCLA site and determines the risk posed to public health and/or the environment.

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Satellite Meetings: Small group meetings to permit more informal yet in-depth discussion of issues pertinent to the composition of the group. The group may be representative of a particular neighborhood, such as a neighborhood association, or be of like cultural or language background.

Site Discovery: A step in the CERCLA process to review records and historical practices at the site to learn of conditions that could present risk to human health and/or the environment.

Site Investigation: A step in the CERCLA process following a preliminary assessment, to collect sufficient information to score the site, using the Hazard Ranking System, and to determine if the site presents an immediate threat that requires prompt response action.

Soil Vapor Extraction: A treatment technology – used by NASA as part of the cleanup effort on-site at JPL – that removes vapors from air spaces in contaminated soil by setting up a pressure gradient or vacuum.

Source Area: The location where hazardous substances were originally released and normally where the highest concentrations of chemicals of concern can be found. In the case of the environmental cleanup effort at and near JPL, the source area is located on JPL property.

Stakeholder(s): Any individual or party that has an interest in the outcome of a remedial decision.

Superfund Amendments and Reauthorization Act of 1986 (SARA): The federal law reauthorizing and expanding CERCLA; it included a provision to extend CERCLA requirements to federal facilities.

Surface water: Water that flows over or is stored on the ground surface.

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U.S. Environmental Protection Agency (EPA): A federal agency responsible for protecting the human health and the environment.

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Vadose Zone: The region between the water table deep underground and the land surface where the moisture content of the soil is less than saturation.

Volatile Organic Compound (VOC): An organic (carbon-containing) compound that evaporates (volatilizes) readily at room temperature.

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Water Purveyor: A public utility, mutual water company, county water district, or municipality that delivers drinking water to customers.

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Last Modified: Aug 27 2016 12:06PM
Version 3.0_2013.10.01