Environmental Terms and Definitions

Infiltration
(1) the penetration of water through the ground surface into sub-surface soil or the penetration of water from the soil into sewer or other pipes through defective joints, connections, or manhole walls. (2) a land application technique where large volumes of waste water are applied to land, allowed to penetrate the surface and percolate through the underlying soil. (See: percolation).

Activated sludge
An aerobic biological process for conversion of soluble organic matter to solid biomass, removable by gravity or filtration.

Action level
The exposure level (the material's concentration in air) at which OSHA regulations to protect employees take effect (29 CFR 1910.1001-1047); e.g., workplace air analysis employee training, medical monitoring, and record keeping.

Biological monitoring
Analyzing chemicals, hormone levels or other substances in biological materials (blood, urine, breath, etc.) as a measure of chemical exposure, health status, etc. in humans or animals. A blood test for lead is an example of biological monitoring.

CERCLA
Comprehensive Environmental Response, Compensation and Liability Act. See "Superfund."

Consumer Product Safety Commission (CPSC)
The CPSC, a federal commission, protects the public from injury caused by consumer products. The CPSC evaluates products, investigates the causes of product-related injuries and issues and enforces safety standards

Remediation
Correction or improvement of a problem, such as work that is done to clean up or stop the release of chemicals from a contaminated site. After investigation of a site, remedial work may include removing soil and/or drums, capping the site or collecting and treating the contaminated fluids.

Superfund (federal and state)
The federal and state programs to investigate and clean up inactive hazardous waste sites.

Ingestion
Swallowing (such as eating or drinking). Chemicals in or on food, drink, utensils, cigarettes, hands, etc. can be ingested. After ingestion, chemicals may be absorbed into the blood and distributed throughout the body.

World Health Organization (WHO)
WHO, an agency of the United Nations, carries out public and environmental health programs throughout the world.