California Department of Health Services (DHS), Radiological Health Branch: A state agency which enforces radiation control laws and regulations designed to protect radiation workers, the public, and the environment.

California Environmental Quality Act (CEQA): A state law mandating environmental impact review of governmental action.  CEQA requires that public agencies study the significant environmental effects of proposed activities and that the public be informed and allowed to comment on project decisions.

Clean Water Act (CWA): Federal law of 1977 enforced by U.S. EPA. A key provision is that “any person responsible for the discharge of a pollutant or pollutants into any waters of the United States from any point source must apply for and obtain a permit.” Discharge permits are required for stormwater runoff from cities and other locations and are issued by Regional Water Quality Control Boards.

Contamination: Introduction into water, air, and soil of microorganisms, chemicals, toxic substances, wastes, or wastewater in a concentration that makes the medium unfit for its next intended use. Also applies to surfaces of objects, buildings, and various household and agricultural use products.

Corrective Action: EPA can require treatment, storage and disposal (TSDF) facilities handling hazardous waste to undertake corrective actions to clean up spills resulting from failure to follow hazardous waste management procedures. The process includes cleanup procedures designed to guide TSDFs.

Decontamination and Decommissioning (D&D): Requirement of the Department of Energy (DOE) for the cleanup and decommissioning of buildings containing radioactive and hazardous materials. The DOE properly characterizes, decontaminates, dismantles, and disposes of the materials.

Department of Toxic Substances Control (DTSC): A department within the California Environmental Protection Agency (Cal/EPA) that oversees the investigation and remediation of hazardous waste sites.

Dioxins: A group of generally toxic organic compounds that may be formed as a result of incomplete combustion (as may occur in incineration of compounds containing chlorine). RCRA regulations require a higher destruction and removal efficiency (DRE) for dioxins and related furans (99.9999 percent) burned in incinerators than the DRE required for most other organic compounds (99.99 percent).

Engineered backfill:  backfill, e.g. soil or other material, that meets material and compaction specifications, ie. grain size, plasticity, both characteristics of the property itself and the way in which it was placed.

Environmental Impact Report (EIR): A detailed report written by the state lead agency describing and analyzing the significant environmental effects of a proposed cleanup project, identifying alternatives and discussing ways to reduce or avoid the possible environmental damage. An EIR is prepared when the lead agency finds substantial evidence that the project may have a significant effect on the environment under CEQA.

Groundwater: Water beneath the earth's surface that flows through soil and rock opening, and; often serves as a primary source of drinking water.

Hazardous waste: Waste substances which can pose a substantial or potential hazard to human health or the environment when improperly managed. Hazardous waste possesses at least one of these four characteristics: ignitability, corrosivity, reactivity or toxicity; or appears on U.S. EPA lists, such as the Superfund Site List.

Health-based cleanup levels: Standards established by the EPA for groundwater, soil and sediment that are based on human exposure levels i.e. ingestion. 

Hydrogeology The geology of groundwater, with particular emphasis on the chemistry and movement of water.

Information Repository: Designated locations that provide public access to site-related documents as required by DTSC.

Interim Measures: A cleanup action taken to protect public health and the environment while long-term solutions are being developed.  An Interim Measure may be conducted anytime during a remediation program.

National Pollutant Discharge Elimination System (NPDES):  A program under the Clean Water Act mandated by the RWQCB, who sets maximum limits for chemical and radiological contaminants in surface water being discharged.  Under the authority of the Clean Water Act and the NPDES, the RWQCB sets maximum limits for discharge of chemical and radiological contaminants to surface water  such as rivers. These limits, along with requirements for discharge sampling, are incorporated into the site's NPDES Permit which must be renewed every five years.

Polychlorinated Biphenyls (PCBs): A group of toxic, persistent chemicals used in electrical transformers and capacitors for insulating purposes, and in gas pipeline systems as lubricant. The sale and new use of these chemicals, also known as PCBs, were banned by state law in 1979.

Radiation: The process of emitting energy in the form of energetic particles (such as alpha particles or gamma radiation), light or heat.

Radioactive Waste: Any waste that emits energy as rays, waves, streams or energetic particles. Radioactive materials are often mixed with hazardous waste, from nuclear reactors, research institutions, or hospitals.

Radioactive Materials: Materials that emit ionizing radiation.

RCRA Facility Investigation (RFI): A series of investigations and studies that is the subsequent step in the corrective action process following a RCRA Facility Assessment to identify the types and extent of chemicals of concern at the site and to determine cleanup criteria (Remedial Investigation), and to provide an evaluation of the alternatives for remediating any identified soil or groundwater problems (Feasibility Study).

RCRA Facility Assessment: A detailed, preliminary site assessment of a treatment, storage, and disposal facility that may be required to undergo some form of corrective action under RCRA.  The first step in the corrective action process is an investigation to determine whether or not potential substances or other constituents of concern exist in soils or groundwater at or near a facility. A lead agency, such as DTSC, gathers information about potential chemical releases relative to chemical usage, storage and treatment at the site.

Regional Water Quality Control Board (RWQCB): The RWQCB is the lead agency responsible for regulating surface water discharge activities. The RWQCB also shares responsibilities with DTSC for monitoring discharges to groundwater.

Remediation: Cleanup of a site to levels determined to be health protective for its intended use.  The cleanup process is a comprehensive program for the clean-up (remediation) of a contaminated site. It involves investigation, analysis, development of a cleanup plan and implementation of that plan.

Resource Conservation and Recovery Act (RCRA): A 1976 amendment to the first federal solid waste legislation, the Solid Waste Disposal Act of 1965. In RCRA, Congress established initial directives and guidelines for U.S. EPA to regulate and manage solid waste, including hazardous waste. RCRA established a regulatory system to track hazardous substances from the time of generation to final disposal. The law requires safe and secure procedures to be used in treating, transporting, storing and disposing of hazardous wastes. RCRA was designed to prevent new, uncontrolled hazardous waste sites.

Sediment: The soil, sand and minerals at the bottom of surface waters, such as streams, lakes and rivers. Sediments capture or adsorb contaminants. The term may also refer to solids that settle out of any liquid.

Statement of Basis: A document which describes the basis for DTSC's proposed remedy and cleanup standards.

U.S. Department of Energy (DOE): Federal agency responsible for energy policy and nuclear safety.

U.S. Environmental Protection Agency (EPA):  A federal agency established in 1970 charged with protecting human health and the environment.

Ventura County Air Pollution Control District (VCAPCD):  A county agency responsible for establishing and enforcing local air pollution regulations that meet or exceed requirements of the Federal and California State Clean Air Acts, and the California Health and Safety Code.

Ventura County Environmental Health Division (VCEHD): Through an agreement with the State of California, the VCEHD is responsible for enforcing regulations on hazardous waste generation, including manifest preparation (shipping documentation) and temporary on-site storage.