Environmental Terms and Definitions

Agricultural pollution
The liquid and solid wastes from farming, including, runoff from pesticides, fertilizers, and feed- lots; erosion and dust from plowing; animal manure and carcasses, crop residues, and debris.

Odor threshold
The lowest concentration of a chemical that can be smelled. Different chemicals have different odor thresholds. Also, some people can smell a chemical at lower concentrations than others can.

AHM
Acutely Hazardous Material

Interim Remedial Measure (IRM)
An action taken at a contaminated site to reduce the chances of human or environmental exposure to site contaminants. Interim remedial measures are planned and carried out before comprehensive remedial studies.

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

Preliminary Site Assessment (PSA)
A process followed by the NYS Department of Environmental Conservation (DEC) to determine if a site contains hazardous waste and its potential for harming the public health or environment.

Marsh
A type of wetland that does not accumulate appreciable peat deposits and is dominated by herbaceous vegetation.Marshes may be either fresh or saltwater and tidal or non-tidal.(See: wetlands).

Volatile organic compound (VOC)
An organic chemical that evaporates readily. Petroleum products such as kerosene, gasoline and mineral spirits contain VOCs. Chlorinated solvents such as those used by dry cleaners or contained in paint strippers are also VOCs. See "organic" and "volatile".

Latency period
The period of time between exposure to something that causes a disease and the onset of the health effect. Cancer caused by chemical exposure may have a latency period of 5 to 40 years.

Maximum Contaminant Level (MCL)
The highest (maximum) level of a contaminant allowed to go uncorrected by a public water system under federal or state regulations. Depending on the contaminant, allowable levels might be calculated as an average over time, or might be based on individual test results.