NASA Insignia Santa Susana Field Laboratory
Environmental Cleanup and Closure
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Terms List

  1. A - D
  2. Area of Impacted Groundwater
  3. Agreement in Principle
  4. Administrative Order on Consent
  5. Area of Concern
  6. Benzo(a)pyrene
  7. Best Management Practice
  8. Bedrock Vapor Extraction
  9. California Environmental Quality Act
  10. Comprehensive Environmental Response Compensation and Liability Act
  11. Characterization
  12. Chemical Background Study
  13. Clean Closure
  14. Cleanup
  15. Corrective Measures Implementation
  16. Corrective Measures Study
  17. Containment of Concern
  18. Consent Order for Corrective Action
  19. Contaminant
  20. Corrective Action Process
  21. Consulting Parties
  22. Cultural Resources
  23. Dioxin
  24. California Department of Toxic Substances Control
  25. E - O
  26. Ecological Receptor
  27. Ecological Risk Assessment
  28. Environmental Impact Statement
  29. Elevated Concentration
  30. Environmental Cleanup
  31. Environmental Protection Agency
  32. Environmentally Sensitive Area
  33. Ethnographic Study
  34. Fault
  35. Groundwater Extraction Treatment System
  36. Groundwater
  37. Groundwater Plume
  38. Groundwater Source Area
  39. Hazardous Waste
  40. Historic Property
  41. Human Risk Assessment
  42. Information Repository
  43. Interim Source Removal Action
  44. Liquid Oxygen
  45. Look-up Table
  46. Monitored Natural Attenuation
  47. Monitoring Wells
  48. National Environmental Policy Act
  49. NPDES Permit
  50. Operable Unit
  51. P - R
  52. Programmatic Agreement
  53. Polycyclic Aromatic Hydrocarbons
  54. Polychlorinated Biphenyls
  55. Resource Conservation and Recovery Act
  56. RCRA Post Closure Permit
  57. Regulated Waste
  58. Remediation
  59. RCRA Facility Assessment
  60. RCRA Facility Investigation phase
  61. Regional Water Quality Control Board, Los Angeles District
  62. S - Z
  63. Sacred Site
  64. Seep
  65. Solvent
  66. Source Area
  67. Stakeholder(s)
  68. Solid Waste Management Unit
  69. Stormwater Pollution and Prevention Program
  70. Trichloroethylene, also known as trichloroethene, or trichloroethane
  71. Test Stand
  72. Total Petroleum Hydrocarbon
  73. Treatability Study
  74. Volatile Organic Compound


A - D

Area of Impacted Groundwater (AIG)
As part of the SSFL groundwater investigation, NASA is characterizing four plumes that are referred to as AIGs to fill in the data gaps identified in the overall site Groundwater Remedial Investigation report. The four AIGS include the Liquid Oxygen Plant, ELV/Building 204, Coca/Delta, and Alfa/Bravo.
Agreement in Principle (AIP)
The Department of Toxic Substances Control, the Department of Energy and NASA reached an Agreement in Principle in September 2010 agreeing to meet the strict environmental standards for SSFL set by state law (SB 990).
Administrative Order on Consent (AOC)
NASA signed the Administrative Order of Consent (AOC), an agreement with the California Department of Toxic Substances Control (DTSC) in 2010 that requires remediation by 2017 of the soils on the NASA-administered property at SSFL to local background values. When background values are not available, the soils will be remediated to laboratory reporting limits called Look up Table values.
Area of Concern (AOC)
An area where releases of hazardous substances may have occurred or a location where there has been a release or threat of a release of a hazardous substance, pollutant, or contaminant.
Benzo(a)pyrene (BaP)
One of a group of polycyclic aromatic compounds (PAHs). They are not produced or used commercially but are very commonly found, since they are formed as a result of incomplete combustion of organic materials. (See PAH below).
Best Management Practice (BMP)
BMP is a term that describes a set of techniques, measures or structural controls used to manage the quantity and improve the quality of stormwater runoff. A BMP can be installed at a work site such as runoff diversions, silt fences, stream buffers and groundcover vegetation. BMPs serve to decrease the volume and rate of runoff and the amount of pollutants in the runoff. NASA implemented a series of BMPs to improve stormwater quality in the Service Road and ELV hillside.
Bedrock Vapor Extraction (BVE)
Often referred to as BVE, this is a technology that uses vacuum blowers and extraction wells to collect contaminated soil vapor which then can be treated aboveground. NASA conducted a treatability study at SSFL using BVE to see whether or not this technology could be implemented in the bedrock that exists at SSFL and if so, to evaluate its effectiveness in removing volatile organic compounds (VOCs).
California Environmental Quality Act (CEQA)
Created in 1970, CEQA is a statute that applies to environmental activities undertaken by state and local public agencies and it requires them to identify the significant environmental impacts of their actions, and to avoid or mitigate those impacts if feasible.
Comprehensive Environmental Response Compensation and Liability Act (CERCLA)
Also known as Superfund, CERCLA funds and carries out EPA solid waste emergency and long-term removal and remedial activities. These activities include establishing the National Priorities List, investigating sites for inclusion on the list, determining their priority, and conducting and/or supervising cleanup and other remedial actions. CERCLA was passed by Congress in 1980 and amended in 1986.
The process to identify the nature and extent of contamination at a site. Site characterization activities document that sufficient data exist to describe site conditions and identify what else needs to be known about the site.
Chemical Background Study
The purpose of this Study was to establish a regulatory agency-approved, publicly-reviewed, and technically-defensible chemical soil background dataset for SSFL environmental programs. Based in part on community and stakeholder input, the chemical soil background samples were collected from the two selected chemical background reference areas (CBRAs) that included surface soil, subsurface soil, and ephemeral (seasonal; typically dry) drainage sediments. The objective was to collect background soil samples at locations that are representative of the physical and other natural conditions present at SSFL and to provide a basis for comparing analytical results from soil samples collected at SSFL with those derived from the Study. From this analysis, DTSC prepared look-up table values for over 130 chemicals. For more on DTSC look-up tables see DTSC Chemical Look-Up Table Technical Memorandum, Santa Susana Field Laboratory, Ventura County, California.
Clean Closure
RCRA regulations on clean closure (removal and decontamination) are found in 40 CFR §§264.111, §§264.228, and §§264.258. They require all waste residues and contaminated containment system components, contaminated subsoils, and structures and equipment contaminated with waste and leachate to be removed and managed as hazardous waste or decontaminated before the site management is completed.
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.
Corrective Measures Implementation (CMI)
The CMI is the last phase of the RCRA corrective action process. This phase follows the selection of remedy and approval of permit modification or order amendment. The modified permit or amended order should include conditions that specify how the corrective measures are to be implemented.
Corrective Measures Study (CMS)
The general objective of the CMS is to develop and evaluate corrective measure alternative(s) that may be utilized at the facility to address releases of hazardous wastes or constituents from Solid Waste Management Units, Areas of Concern, and other source areas at the facility. The CMS is analogous to the Feasibility Study conducted under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or State Superfund laws.
Containment of Concern (COC)
COCs are substances that are present in a setting at levels that the EPA has determined could cause harmful (adverse) effects to human health or the environment. These are the substances addressed by cleanup actions at a site.
Consent Order for Corrective Action
In August 2007, NASA, Boeing, the U.S. Department of Energy (DOE), and DTSC signed a Consent Order for Corrective Action (State of California DTSC Docket No. P3-07/08-003, 2007; referred to as the “2007 Consent Order”) that addressed the cleanup of soils and groundwater at SSFL. The 2007 Consent Order identified activities for the cleanup of soil and groundwater at SSFL.
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.
Corrective Action Process
Congress amended RCRA in 1984 to require facilities that have treated, stored, or disposed of hazardous wastes to investigate and clean up environmental contaminants released into soil, groundwater, surface water, and air at their sites regardless of the time of the release. This cleanup or remediation process is known as "corrective action."
Consulting Parties (CP)
Section 106 of the NHPA of 1966 [36 CFR 800] requires that federal agencies consult with federal, state, and local agencies, Native American Tribes, other organizations, and members of the public having an interest, in considering the potential effects of proposed actions on historic properties. NASA posted on its website a form for interested parties to request participation in the Section 106 consultation process and also announced the availability of the process at its EIS Scoping public meetings. More than 35 individuals had varying interests in the site and included representatives from California State Historic Preservation Office (SHPO), the Advisory Council on Historic Preservation (ACHP), and tribes. Consultation culminated with a Programmatic Agreement that includes mitigation measures to address the likely adverse effects to historic properties.
Cultural Resources
Cultural resources include historical features as well as architectural and archaeological resources, traditional cultural properties, cultural landscapes, and Indian Sacred Sites. Multiple laws govern agency compliance regarding cultural resources including the National Historic Preservation Act, the Archaeological Protection Act, the American Indian Religious Freedom Act, to name a few. Additionally, Executive Order 13007 requires federal agencies to accommodate access to and ceremonial use of Indian Sacred Sites by religious practitioners and to avoid adversely affecting the physical integrity of such sites. The NASA-administered portion of SSFL has been designated an Indian Sacred Site by the Santa Ynez Band of Chumash Indians.
A family of chlorinated hydrocarbon compounds known to be highly toxic and to persist in the environment for extended periods. They are a common by-product of many industrial and manufacturing processes and result from incomplete combustion in fires and incinerators.
California 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. The DTSC oversees the environmental cleanup program at SSFL.

E - O

Ecological Receptor
Ecological receptors includes any living organisms other than humans, the habitat which supports such organisms, or natural resources which could be adversely affected by environmental contaminations resulting by a release at or migration from a site.
Ecological Risk Assessment
For cleanups conducted under CERCLA and RCRA, Ecological Risk Assessments (ERAs) often are conducted to evaluate whether hazardous chemicals in environmental media might have harmed or have a potential to harm exposed ecological receptors. The overall objective is to provide risk-based information to managers for decision-making to ensure that cleanup actions adequately mitigate risks. To address questions received during public comment NASA did a general review of the ecological assessment to compare the level of protectiveness of cleaning up soil to background, as required by the AOC, as compared with cleaning up only those chemicals that pose unacceptable risk to ecological receptors.
Environmental Impact Statement (EIS)
A National Environmental Policy Act (NEPA) document that outlines the environmental impact of a proposed action by a federal agency. An EIS provides a detailed statement that describes the potential environmental impact of a proposed action and presents any alternatives to those actions as well as measures to mitigate identified impacts.
Elevated Concentration
A concentration which exceeds a human health or ecological screening criteria level, or a background concentration level.
Environmental Cleanup
A comprehensive program for the cleanup (remediation) of a site that contains substances that could cause adverse effects to human health or the environment. It involves investigation, analysis, development of a cleanup plan and implementation of that plan.
Environmental Protection Agency (EPA)
EPA was established on December 2, 1970 to consolidate in one agency a variety of federal research, monitoring, standard-setting and enforcement activities that protect the environment and control pollution.
Environmentally Sensitive Area (ESA)
Within the context of cultural resources studies, an ESA is a location where archaeological sites or other historic properties have been identified that need some measure of active protection. ESA’s may also be biological or paleontological.
Ethnographic Study
An ethnographic study is one of the methods anthropologists use to document various aspects of other cultures in order to make generalizations about human behavior and the operation of social and cultural systems. An ethnographic study is being conducted as part of NASA’s effort to preserve the legacy of the SSFL site.
A break in a rock formation. Over the years, the blocks of rock on either side of the break, or fault, may move in different directions.
Groundwater Extraction Treatment System (GETS)
NASA and Boeing are working to clean up groundwater at a centralized GETS in Area I. Groundwater extracted from 14 wells across SSFL will be delivered via new pipelines and treated at the GETS. The treated water will be discharged at Outfall 019.
For the discussion related to SSFL, the water within the alluvium and/or weathered bedrock and the Chatsworth formation aquifer (present within the unweathered portions of bedrock). As defined in the 2010 Administrative Order on Consent, groundwater also can include soils contaminated by soil vapor (volatile organic compounds [VOCs]) from groundwater.
Groundwater Plume
A volume of a substance that moves from its source to places farther away from the source. NASA is studying four groundwater plumes as part of the groundwater investigation at SSFL.
Groundwater Source Area
The location where hazardous substances were originally released and where the highest concentrations of chemicals of concern can be found. As part of the site wide groundwater investigation at SSFL, NASA is characterizing four plumes, referred to as AIGs, to better understand the groundwater source area beneath NASA-administered property.
Hazardous Waste
Waste substances that can pose a substantial or potential hazard to human health or the environment when improperly managed. Typical hazardous waste contains materials that are toxic, corrosive, ignitable, explosive, or chemically reactive.
Historic Property
Section 110 of the National Historic Preservation Act guides federal agencies to manage their historic properties. Historic property means any prehistoric or historic district, site, building, structure, or object included in or eligible for inclusion in the National Register of Historic Places. The Register is administered by the U.S. Department of the Interior. There are standard criteria by which properties are evaluated and determined to be historic.
Human Risk Assessment
For cleanups conducted under CERCLA and RCRA, Human Health Risk Assessments (HHRAs) often are conducted to evaluate whether hazardous chemicals in environmental media might have harmed or have a potential to harm exposed human receptors. The overall objective is to provide risk-based information to managers for decision-making to ensure that cleanup actions adequately mitigate risks. To address questions received during public comment NASA did a general review of the human risk assessment to compare the level of protectiveness of cleaning up soil to background, as required by the AOC, as compared with cleaning up only those chemicals that pose unacceptable risk to human receptors.
Information Repository
A file available to the public that contains current information, technical reports, and reference documents on an environmental cleanup 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. Detailed information about SSFL is available at the locations listed on the Information Repositories page.
The complete Administrative Record for the SSFL is located at the California Department of Toxic Substances Control (DTSC) Regional Records Center. Contact information for DTSC can also be found on the Information Repositories page.
Interim Source Removal Action (ISRA)
A short-term action undertaken to prevent or mitigate risks to human health or the environment before a final remedy has been selected. The ISRA begun by NASA in 2009 was designed to remove potential sources of contaminants and improve the quality of surface water discharge.
Liquid Oxygen (LOX)
Liquid oxygen (LOX) is used as an oxidizer in rocket propellants. The United States Air Force (USAF) operated a LOX plant in Area I of SSFL during the 1950s and 1960s. All the LOX plant’s buildings and tanks were removed in the 1970s.
Look-up Table (LUT)
The AOC specified that "Upon completion of the DTSC-led chemical background study, a ‘look-up’ table of the chemical cleanup levels will be prepared, which will include both local background concentrations as well as minimum detection limits for specific contaminants whose minimum detection limits exceed local background concentrations.” The Look-Up Table values are the chemical-specific values used to assess if the DOE and NASA Santa Susana Field Laboratory (SSFL) cleanup objectives have been achieved.
Monitored Natural Attenuation
This remediation includes a variety of physical, chemical, or biological processes that, under favorable conditions, act without human intervention to reduce the mass, toxicity, mobility, volume, or concentration of contaminants in soil or groundwater. These in-situ processes include biodegradation; dispersion; dilution; sorption; volatilization; radioactive decay; and chemical or biological stabilization, transformation, or destruction of contaminants.
Monitoring Wells
Wells drilled at specific locations where groundwater can be routinely sampled at selected depths to evaluate groundwater flow patterns, and types and extent of contamination present. A network monitoring wells were installed at SSFL in the mid-1980s and have been regularly sampled since that time.
National Environmental Policy Act (NEPA)
Before a major action is taken that may have a significant impact on the quality of the environment, NEPA requires all federal agencies to consider environmental values in planning actions and activities. NEPA also provides a means to make information about the proposed action available to the public, other federal, state, and local agencies and to obtain the comments and involvement of interested parties.
NPDES Permit
As authorized by the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) permit program controls water pollution by regulating point sources (outfalls that are outlets or drainages from SSFL to regional drainage systems) that discharge pollutants into waters of the United States. At SSFL, discharges of stormwater are regulated under NPDES Permit No. CA0001309, issued to Boeing by the Los Angeles Regional Water Quality Control Board.
Operable Unit (OU)
A site listed that 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.

P - R

Programmatic Agreement (PA)
The document developed through consultation under Section 106 of the NHPA and signed by NASA, the California SHPO, and the ACHP, and the invited signatory the Santa Ynez Band of Chumash Indians. It identifies measures to be taken for the protection and preservation of cultural resources (including Native American elements as well as historic rocket testing features) during implementation of NASA’s Proposed Action.
Polycyclic Aromatic Hydrocarbons (PAH)
A group of over 100 different chemicals that are formed during the incomplete burning of coal, oil and gas, garbage, or other organic substances like tobacco or charbroiled meat. PAHs are usually found as a mixture containing two or more of these compounds, such as soot. Some PAHs are manufactured. These pure PAHs usually exist as colorless, white, or pale yellow-green solids. PAHs are found in coal tar, crude oil, creosote, and roofing tar, but a few are used in medicines or to make dyes, plastics, and pesticides.
Polychlorinated Biphenyls (PCB)
Part of a broad family of man-made organic chemicals known as chlorinated hydrocarbons. PCBs were domestically manufactured from 1929 until 1979, when their manufacture was banned. They have a range of toxicity and vary in consistency from thin, light colored liquids to yellow or black waxy solids. PCBs were formerly used in hundreds of commercial applications including: electrical, heat transfer and hydraulic equipment and in paints, plastics and rubber products as well as in pigments, dyes and many industrial applications.
Resource Conservation and Recovery Act (RCRA)
This was a 1976 amendment to the first federal solid waste legislation, the Solid Waste Disposal Act of 1965. RCRA established a regulatory system to track hazardous wastes from the time of generation to final disposal, a so-called “cradle to grave” approach. The law requires facilities to obtain a permit if they treat, store or dispose of hazardous waste. RCRA is designed to ensure the safe management of hazardous wastes.
RCRA Post Closure Permit
When a hazardous waste management unit stops receiving waste at the end of its active life, it must be cleaned up, closed, and monitored and maintained in accordance with the RCRA closure and post-closure requirements. All hazardous waste management units and the treatment, storage, and disposal facilities at which they are located are subject to the closure and post-closure care requirements found at 40 CRF Part 264/265, Subpart G.
Regulated Waste
The Resource Conservation and Recovery Act (RCRA) requires that a generator determine if its waste is a solid waste and if it is hazardous at the point of generation and if so, it is subject to Subtitle C regulations for handling and disposal.
Cleanup of a site to levels determined to be health-protective for its intended use.
RCRA Facility Assessment (RFA)
This is the initial phase of corrective action. It includes determinations of actual or potential releases for all environmental media (i.e., soil, groundwater, subsurface gas, air, or surface water). The RFA generally includes historical records research and may include limited sampling.
RCRA Facility Investigation phase (RFI)
A series of investigations and studies that is a step in the corrective action to identify the types and extent of chemicals of concern at the site and establish cleanup criteria.
Regional Water Quality Control Board, Los Angeles District (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.

S - Z

Sacred Site
A specifically delineated location on federal land that is identified by an appropriately authoritative representative of an Indian religion. NASA is working with the Santa Ynez Band of Chumash Indian tribe on an area that includes the Burro Flats Painted Cave, which contains some of the best preserved pictographs in the state.
An area where groundwater reaches the earth’s surface from an underground aquifer.
Liquid capable of dissolving other substances. Trichloroethene, also known as trichloroethylene (TCE), was the primary solvent used in the 1950s and ‘60s for cleaning rocket engine components and other cleaning purposes.
Source Area
The location where hazardous substances were originally released and normally where the highest concentrations of chemicals of concern can be found.
Any individual or party that has an interest in the outcome of a remedial decision.
Solid Waste Management Unit (SWMU)
Any area at a facility where solid or hazardous wastes have been placed at any time, or any area where solid wastes have been routinely and systematically released.
Stormwater Pollution and Prevention Program (SWPPP)
Construction site operators are required to prepare a SWPPP for their stormwater discharges. The SWPPP describes all the construction activities involved at the site and the measures the operators will take to prevent stormwater runoff, control sediment and erosion, and comply with the requirements of NPDES permit and the Clean Water Act. NASA prepared a SWPPP prior to on-site demolition activities.
Trichloroethylene, also known as trichloroethene, or trichloroethane (TCE)
Trichloroethylene is a nonflammable, colorless liquid with a somewhat sweet odor and a sweet, burning taste. It is used mainly as a solvent to remove grease from metal parts, but it is also an ingredient in adhesives, paint removers, typewriter correction fluids, and spot removers. TCE was used in rocket engine testing at four NASA test stands in SSFL Area II during the 1960s and was curtailed. Limited use of TCE continued at one test stand through the early 1980s, to support Space Shuttle Main Engine research.
Test Stand
Open-framed, metal structures with concrete foundations (and related buildings) where mechanical and vibrational tests were conducted on engines. At SSFL, they were built in support of Space Shuttle Main Engine activities and consisted of four testing locations−Alfa, Bravo, Coca, and Delta. Each Test Stand had three or more “positions” to fire the engines.
Total Petroleum Hydrocarbon (TPH)
A term used to describe a large family of several hundred compounds that originally come from crude oil. Because there are so many different chemicals in crude oil and in other petroleum products, it is not practical to measure each one separately. However, it is useful to measure the total amount of TPH at a site. TPH is a mixture of chemicals but they are all made mainly from hydrogen and carbon (hydrocarbons). Some chemicals found in TPH include hexane, jet fuels, mineral oils, benzene and toluene, as well as other petroleum products and gasoline components.
Treatability Study
Treatability studies are required to demonstrate the implementability, feasibility, and effectiveness of such technologies on particular chemicals at the levels present and under site specific conditions. NASA is conducting treatability studies to assess treatment in place (also known as in situ treatment) technologies, and other methods to achieve the required cleanup levels.
Volatile Organic Compound (VOC)
Organic (containing carbon) compounds that evaporate readily into the air. They often have a sharp smell and can be found in many products such as office equipment, adhesives, carpeting, upholstery, paints, solvents and cleaning products.

Unless otherwise indicated, all images are provided by NASA.

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