Glossary

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REACTIVITY:

A characteristic of compounds which are normally unstable and readily undergo violent change, react violently with water, can produce toxic gases with water, or possess other similar properties. Reactivity is one characteristic that can make a waste hazardous.

RECHARGE ZONES: T

he areas of land that allow water to replenish an aquifer. This process occurs naturally when rainfall filters down through the soil or rock into an aquifer, usually in the higher gradient section overlying the aquifer. Artificial recharge is through injection wells or by spreading water over groundwater reservoirs for any given area. 

RECHARGE:

Water added to the saturation zone of an aquifer. For instance, rainfall that seeps into the ground.

REGULATORY AGENCY:

The State Board, a Regional Board, or any local, state, or federal agency which has responsibility or authority for regulating UST's or which has responsibility for cleanup and overseeing the cleanup fromunauthorized releases from UST's.

RELEASE:

Any spilling, leaking, emitting, discharging, escaping, leaching, or disposing from a UST into or on the waters of the state, the land, or the subsurface soils.

REMEDIAL ACTION PLAN (RAP):

A plan of activities taken to correct a problem such as fuel contamination of soil or groundwater. Only taken after the completion of a Corrective Action Plan determining what method would be used to remediate the site. Not necessary in many cases.

REMEDIAL INVESTIGATION/FEASIBILITY STUDY (RI/FS):

A series of investigations and studies 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.

REMEDIATION:

Cleanup of a site to levels determined to be health-protective for its intended use.

REMOVAL ACTION:

A short-term effort designed to stabilize or clean up a hazardous waste site that poses an immediate threat to human health or the environment. Removal actions include removing tanks or drums of hazardous substances that were found on the surface and installing drainage controls or security measures, such as a fence at the site. Removal actions also may be conducted to respond to accidental releases of hazardous substances. CERCLA places time and money constraints on the duration of removal actions. 

REPORTABLE QUANTITY (RQ):

The quantity of hazardous substances that, when released into the environment, can cause substantial endangerment to public health or the environment. Under CERCLA, the federal government must be notified when quantities equaling or exceeding RQs specified in regulations are released.

RESOURCE CONSERVATION AND RECOVERY ACT (RCRA):

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.

RESPONSIBLE PARTY (RP):

Owner or operator of an underground storage tank ultimately responsible for the underground tank release.

RETURN ON EQUITY:

Measured by the ratio of net cash flow to equity (net cash flow/equity).

REVERSE OSMOSIS (WATER QUALITY):

An advanced method of water or wastewater treatment that relies on a semi-permeable membrane to separate waters from pollutants. An external force is used to reverse the normal osmotic process resulting in the solvent moving from a solution of higher concentration to one of lower concentration.

RISK ASSESSMENT:

The quantitative evaluation of hazards posed by exposure to toxicants. A risk assessment looks at the chemicals detected at a site, the frequency and concentration of detected chemicals, the toxicity of the chemicals and how people can be exposed, and for how long. Routes of exposure to people are generally through ingestion, such as eating, contact with the skin, or inhalation. The most significant potential routes of exposure are through ingestion and contact with the skin. Based on the standard risk assessment guidelines established for use nationwide by U.S. EPA, exposures for an on-site resident are generally assumed to be daily contact over a 30-year period starting with children ages 0-6, and continuing from 6-30 years. The health risk assessment cannot predict health effects; it only describes the increased possibility of adverse health effects, based on available scientific information.

RISK-BASED CORRECTIVE ACTION (RBCA):

Methodology used to evaluate the potential and existing risks of a contamination to determine if, or how much, remediation is required.

RISK-BASED DECISION-MAKING (RBDM):

Refers to a process through which decisions are made about contaminated sites according to the risk each site poses to human health and the environment. RBDM is a mechanism for identifying necessary and appropriate action at any phase of the corrective action process. Depending on known or anticipated risks to human health and the environment, appropriate action can include site closure, monitoring and data collection, active or passive remediation, containment, or imposition of institutional controls.

RUNOFF:

Precipitation that flows over land to surface streams, rivers, and lakes.

RWQCB:

Regional Water Quality Control Boards located in nine locations in California which have the authority for setting cleanup levels, and regulate waste discharges from point and non-point sources. May act as local oversight agencies.