What is turbidity?
Definition of turbidity
Turbidity is a measure of the clarity of water. Water that has a very high turbidity will appear cloudy or opaque while water with very low turbidity will appear clear or translucent. Turbidity is caused by particles such as silt, clay, microorganisms, and organic matter. Turbidity is not a direct measure of these particles but rather a measure of how these particles scatter light. The American Public Health Association defines turbidity as the "expression of the optical property that causes light to be scattered and absorbed rather than transmitted in straight lines through the sample." For more information, see the Turbidity Science, by Michael J. Sadar.