Turbidity is a measure of water’s lack of clarity
and is an important indicator of water quality.
Water with high turbidity is cloudy, while water
with low turbidity is clear. The cloudiness is produced by light reflecting off particles
in the water; therefore, the more particles in the water, the higher the turbidity. High
turbidity can be detrimental to water quality as more sunlight is absorbed, causing an
increase in water temperature. According to the USGS, the turbidity of surface water is
usually between 0 and 50 NTU. Turbidity is often higher than this, however, especially
after heavy rain when water levels are high.