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  2. Harmful Algal Blooms (HABs) in Water Bodies

What is Nutrient Pollution? (Text Only)

Nutrient pollution occurs when there is an excess of nitrogen and phosphorus

  • 50 out of 50 states are impacted by nutrient pollution.
  • States have identified about 15,000 waterbodies in the United States with nutrient-related problems.
  • Reported drinking water violations for nitrates have nearly doubled in the last decade.

Nutrient pollution is widespread

  • Did you know the Mississippi River Basin spans 31 states and ultimately drains into the Gulf of America?
  • The Mississippi River is the largest in the United States and creates the third largest river basin in the world.
  • Nutrient pollution from the Mississippi River Basin is causing a large “dead zone” in the Gulf of America that cannot support aquatic life.

Where does nutrient pollution come from?

Fossil fuels

  • 250 million cars and trucks in the United States release more than 7 million tons of nitrogen oxides into the atmosphere, contributing to pollution in the air and water.

Agriculture

  • Animal manure, excess fertilizer applied to crops and fields, and soil erosion make agriculture a large source of nutrient pollution.
  • Livestock production generates close to 1 billion tons of manure.
  • From 1964 to 2008, agricultural fertilizer use increased by 25%.

Urban sources

  • About 10% of the nutrients flowing from the Gulf of America come from urban stormwater and wastewater/sewage treatment plants.

Industry

  • In 2012, 592 industrial facilities released 100,000 tons of nitrate compounds, equal to 3,000 full railroad cars.

Impacts on the nation

Nutrient pollution is one of America’s most serious water pollution issues today. Limiting nutrient pollution will protect people’s health, support the economy, and keep America’s waters safe for swimming and fishing.

Sources

  • EPA Clean Water Act 303 (d) listings, May 2012
  • The Facts about Nutrient Pollution, EPA Fact Sheet, April 2012, EPA Mississippi River Gulf of America Watershed Nutrient Task Force
  • USGS, “Phosphorus and Groundwater: Establishing Links Between Agriculture Use and Transport to Streams"
  • EPA “Nutrient Pollution"
  • An Urgent Call to Action: Report of the State-EPA Nutrient Innovations Task Group (August 2009) (pdf) (5.61 MB)
  • 2010 EPA Toxics Release Inventory
  • EPA 2008 National Emissions Inventory and Transportation Energy Data book
  • Comparison of nitrogen and phosphorus sources in the Chesapeake Bay and Gulf of America watersheds (USGS 2008; Chesapeake Bay Program 2009) Note: urban and population-related sources include urban stormwater and municipal wastewater treatment.

Harmful Algal Blooms (HABs) in Water Bodies

  • Basic Information on HABs
    • Learn about HABs
    • What Causes HABs
    • Exposure to HABs
    • Effects of HABs
    • What You Can Do
  • Trends, Monitoring Results & Forecasts
    • HAB Monitoring and Trends
    • HAB Forecasts
    • HAB Advisories
  • Managing HABs
    • Managing HABs in Surface Water
    • Managing Algal Toxins in Drinking Water
    • Managing Algal Toxins in Recreational Waters
  • HAB Laws, Tools and Data
    • HABHRCA
    • HAB Tools
    • HAB Data
  • HAB Methods & Research
    • HAB Methods
    • HAB Research
  • HAB Resources
    • EPA Outreach on HABs
    • Labs that Analyze for Cyanobacteria and Cyanotoxins
    • State & Tribal HAB Programs and Resources
    • State & Tribal Toxin Thresholds and HAB Advisory Decision Methods
    • HAB Resources from Other Federal Agencies and Organizations
    • Recent Papers, Upcoming Meetings and Webinars
Contact Us about HABs
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on February 5, 2025
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