Turbidity measures the scattering light through water caused by materials in suspension or solution. The suspended and dissolved material can include clay, silt, finely divided organic and inorganic matter, soluble colored organic compounds, and plankton and other microscopic organisms.

Turbidity can result from soil erosion and runoff that causes the water to be brown; this is called clay turbidity.

Turbidity can also result from tiny suspended plants in water (algal blooms) that causes water to be green; this is called plankton turbidity.

High turbidity limits sunlight penetration in water, inhibits growth of aquatic plants, and can upset aquatic ecosystems.

High clay turbidity is an indication of soil erosion which leads to sedimentation of streams, rivers, lakes, and reservoirs. This is considered to be Alabama’s number one water pollution problem!