Phosphorus is widely distributed over the surface of the earth in biologically available forms cycling within plants, animals, soil, and water. Water quality problems associated with P are generally confined to surface waters only. Phosphorus is immobile in soils and does not leach. Consequently, contamination of groundwater is rarely a problem. The rest of this brochure discusses P as a surface water quality concern.
Many human activities contribute P to surface waters.
Activities associated with modern agriculture often significantly increase soil erosion and water runoff from land and transport sediment into surface waters. Phosphorus in fertilizers and manures will not leach through soils to pollute groundwater because it is held tightly to soil particles. However, the soil particles that are transported off the field by erosion P will pollute surface waters. Soil Erosion Control Runoff and soil erosion from agricultural lands are major causes of P pollution of surface waters. Consequences of soil erosion include removal of fertile topsoil, accelerated eutrophication and sedimentation of surface waters, destruction of fish and wildlife habitat, and decreased recreational and aesthetic value of surface waters.