Turbidity is a measure of the cloudiness of water and can often be a problem in water with a high iron content, often removing the iron will remove the turbidity.
Water cloudiness is caused by material, such as dirt and residue from leaves, which is suspended (floating) in the water. If you look at a river after a storm, it will be full of sediment and definitely not clear, you are seeing all of the suspended soil in the water. Usually the materials that cause turbidity in our drinking water either settle out or are filtered before the water arrives in our drinking glass at home.
Turbidity may be composed of organic and/or inorganic constituents. Organic particulates may harbour high concentrations of bacteria, viruses, and protozoan, therefore, turbid conditions may increase the possibility for waterborne disease.