What are the sources of nutrient pollution?  

Both point source and non-point sources of nitrogen and phosphorus can move nutrients from land and facilities into bodies of water. 

• Non-point sources: Surface water runoff and groundwater flow from agricultural and urban areas.
• Point sources: Discharges from industrial and wastewater treatment facilities and septic systems.

Where nutrients originate

• Manures and chemical fertilizers used in agriculture
• Lawn fertilizers, yard and pet waste, and some detergents from residential and commercial properties
• Soil erosion that carries away nutrient-rich soils
• Discharge from community sewage and industrial wastewater treatment plants
• Nitrogen compounds from the atmosphere, nitrogen oxide and ammonia, that deposit into sediment. This happens after burning fossil fuels and from certain agricultural practices.