How do phosphates enter the environment?
Many phosphates occur naturally in the environment as minerals and as essential nutrients for plant and animal life. In the phosphorus nutrient cycle, plants absorb phosphates from water and soil. Phosphates are available to animals and humans when plants (and other animals) are consumed and are then returned to the environment through animal and human waste and decomposition of plants and animals. In modern industrial societies, the major sources of phosphates to the environment include natural sources, fertilizers and waste runoff from animal feed lots. Those municipal sewage facilities not practicing phosphate removal can be a significant source of phosphates entering the environment.
