A clear, cone-shaped container used to measure the volume of settle able solids in a specific volume of water.

The inability of two or more solids or liquids to readily dissolve into one another.

Not easily penetrated by water.

Particles or other objects that cause water to be unclear.

Any biological entity or process, or community whose characteristics show the presence of specific environmental conditions or pollutants.

Microorganisms, such as coli-forms, whose presence is indicative for pollution or for the presence more harmful microorganisms.

Tests for a specific contaminant, group of contaminants, or constituent which signals the presence of something else.

Introduction of pollutants from a non-domestic source into a publicly owned wastewater treatment system. Indirect dischargers can be commercial or industrial facilities whose wastes enter local sewers.

Penetration of water into a medium, for instance the soil.

The stream of water that enters any system or treatment unit.

chemical that interferes with a chemical reaction, such as precipitation.

The introduction of a chemical or medium into the process water to alter its chemistry or filter specific compounds.

An atom in a solution that is charged, either positively (cations) or negatively (anions).

The replacement of undesirable ions with a certain charge by desirable ions of the same charge in a solution, by an ion-permeable absorbent.

Chemical substances of mineral origin, not of basically carbon structure.

Applying water or wastewater to land areas to supply the water and nutrient needs of plants.