Turbidity is a measure of water clarity, which is influenced by how much the material suspended in water decreases the passage of light through the water. Suspended materials include soil particles (clay, silt, and sand), algae, plankton, microbes, and other substances. Turbidity can also affect the color of the water.
Higher turbidity increases water temperatures, which can then reduce dissolved oxygen concentrations. Sources of turbidity include stormwater runoff, erosion, and algal growth. Turbidity is measured in nephelometric turbidity units or NTUs, with higher values indicating higher turbidity.