Excessive amounts in water can lead to over-productive aquatic growth. Nitrogen is naturally abundant in the environment and also is introduced through sewage and fertilizers. A pH of 7 is neutral, less than 7 is acidic, and greater than 7 is basic. Phosphorus enters streams from point sources, primarily wastewater-treatment facilities, and from nonpoint sources, such as applications of lawn fertilizers and disposal of animal wastes. Water cloudiness is caused by material, such as dirt and residue from leaves, that is suspended in the water.
Clear water has low turbidity.
Brown, silt-laden water, such as a river during a storm, has high turbidity.