FORMER UNOCAL 76
(a/k/a DURRAND DISTRIBUTING)
YAKIMA, YAKIMA COUNTY, WASHINGTON
January 29, 2002
Washington State Department of Health
Under a Cooperative Agreement with the
Agency for Toxic Substances and Disease Registry
TABLE OF CONTENTS
- Agency for Toxic Substances and Disease Registry (ATSDR):
- The principal federal public health agency involved with hazardous waste issues, responsible for preventing or reducing the harmful effects of exposure to hazardous substances on human health and quality of life. ATSDR is part of the U.S. Department of Health and Human Services.
- An underground formation composed of materials such as sand, soil, or gravel that can store and/or supply groundwater to wells and springs.
- Benzene, ethylbenzene, toluene, and xylenes
- Any substance that can cause or contribute to the production of cancer.
- Comparison value:
- A concentration of a chemical in soil, air or water that, if exceeded, requires further evaluation as a contaminant of potential health concern. The terms comparison value and screening level are often used synonymously.
- Any chemical that exists in the environment or living organisms that is not normallyfound there.
- A dose is the amount of a substance that gets into the body through ingestion, skinabsorption or inhalation. It is calculated per kilogram of body weight per day.
- Contact with a chemical by swallowing, by breathing, or by direct contact (such asthrough the skin or eyes). Exposure may be short term (acute) or long term (chronic).
- Water found underground that fills pores between materials such as sand, soil, orgravel. In aquifers, groundwater often occurs in quantities where it can be used fordrinking water, irrigation, and other purposes.
- Hazardous substance:
- Any material that poses a threat to public health and/or the environment. Typicalhazardous substances are materials that are toxic, corrosive, ignitable, explosive, orchemically reactive.
- Maximum Contaminant Level (MCL):
- A drinking water regulation established by the federal Safe Drinking Water Act. Itis the maximum permissible concentration of a contaminant in water that is delivered to the free flowing outlet of the ultimate user of a public water system. MCLs are enforceable standards.
- Soil, water, air, plants, animals, or any other part of the environment that can contain contaminants.
- Model Toxics Control Act (MTCA):
- The hazardous waste cleanup law for Washington State.
- Monitoring wells:
- Special wells drilled at locations on or off a hazardous waste site so water can besampled at selected depths and studied to determine the movement of groundwater and the amount, distribution, and type of contaminant.
- Parts per billion (ppb)/Parts per million (ppm):
- Units commonly used to express low concentrations of contaminants. For example, 1 ounce of trichloroethylene (TCE) in 1 million ounces of water is 1 ppm. 1 ounce of TCE in 1 billion ounces of water is 1 ppb. If one drop of TCE is mixed in a competition size swimming pool, the water will contain about 1 ppb of TCE.
- An area of contaminants in a specific media such as groundwater.