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ENVIRONMENTAL HEALTH CONCERNS AND TOXIC CHEMICALS WHERE YOU LIVE, WORK, AND PLAY

Runoff

About

Runoff is water from rain, melted snow, or irrigation that is not absorbed and held by the soil, but runs over the ground and through loose soil. As runoff moves, it picks up and carries pollution. It can then deposit the pollution into ponds, lakes, coastal waters, and underground sources of drinking water.

What is it?

Agricultural runoff is water leaving farm fields because of rain, melted snow, or irrigation. 

Why is it a concern?

Agricultural runoff can deposit pollution into ponds, lakes, coastal waters, and underground sources of drinking water. This pollution may come from: 

Polluted agricultural runoff is the leading source of water pollution in rivers and lakes. The pesticides in runoff can build up in fish, which can expose people who eat the fish to high levels of chemicals. Polluted agricultural runoff can also trigger harmful algae blooms in coastal waters.

What pollutants are of greatest concern and who is at risk?

High levels of nitrates from fertilizers in runoff can contaminate drinking water. Nitrates can also cause potentially fatal “blue baby” syndrome in very young infants by disrupting oxygen flow in the blood. 
Other pollutants from agricultural runoff include: 

  • Heavy metals
  • Herbicides
  • Nutrients such as nitrogen and phosphorus
  • Pesticides
  • Salts
  • Soil particles

Farm workers and residents of nearby communities may be at risk.

National Library of Medicine Resources and Databases

Additional Resources

What is it?

Heavy falls of rain or snow may result in unusually high quantities of surface water, or stormwater. Storm sewers carry stormwater runoff to a treatment plant or receiving stream.

Why is it a concern?

As stormwater runs over streets, sidewalks, driveways, or yards, it can pick up pollution, dirt, and chemicals, especially fertilizers and pesticides from lawns. Polluted stormwater that runs into a sewer system can flow into and contaminate sources of water for drinking, swimming, and fishing.

What pollutants are of greatest concern and who is at risk?

Stormwater runoff may contain fertilizers, pesticides, and other pollution. 
People who drink well water or live or work near where stormwater runoff is visible may be at risk for harm from contamination.
 

National Library of Medicine Resources and Databases

Additional Resources

What is it?

Urban and industrial runoff comes from cities and suburbs where there are roads, parking lots, pavement, construction sites, rooftops, and factories. Many urban areas have stormwater drain systems that channel the runoff into local waterways through pipes, ditches, and drainage canals. Stormwater systems reduce flooding, mud, and erosion in urban areas. Runoff will also flow directly into local waterways. 

Why is it a concern?

Urban and industrial runoff is a major source of water pollution in streams, lakes, rivers, and reservoirs. The pollution can contaminate sources of water for drinking, swimming, and fishing. It can make recreational areas unsafe and unpleasant.

What pollutants are of greatest concern and who is at risk?

Runoff pollution can include:

  • Garbage and other debris
  • Heavy metals, dirt, and salt from roads
  • Oil, grease, antifreeze, and other toxic chemicals from vehicles and vehicle maintenance facilities 
  • Pesticides and fertilizers from lawns and gardens 
  • Viruses and bacteria from pet  waste and failing septic systems

Industrial runoff can include site-specific pollutants such as:

  • Dirt and chemicals from construction sites
  • Liquids from animal hides in tannery yards
  • Wastewater  from meatpacking facilities

People who drink well water or live or work near where urban or industrial runoff is visible may be at risk for harm from contamination.

National Library of Medicine Resources and Databases

Additional Resources

Reduce your risk

  • Do you use well water?
  • Do you live near an industrial site or factory?
  • Do you live near lawns where fertilizers and pesticides are used?
  • Do you have pets  or other animals?
  • Routinely test well water for chemical contamination.
  • If your well water has high levels of chemicals, contact your local or state health agency or the Centers for Disease Control and Prevention for information on how to reduce your exposure to these chemicals.
  • Regularly maintain wastewater systems  such as septic tanks so that wastewater does not reach the ground surface.
  • Properly dispose of all household chemical products  such as solvents, paint, and motor oil.
  • Maintain your car or truck. Fix oil leaks and always recycle used oil, antifreeze, and other fluids. Never dump anything down a storm drain.
  • Wash your car at a commercial facility rather than in the street or in your driveway. If you wash your car at home, wash it on your lawn. 
  • Drive less. Leave your car at home at least one day each week and take a bus, carpool, or bike to work. Combine errands when you drive. Get vehicle emissions systems checked and repaired as needed. Buy a low-emissions vehicle. 
  • Reduce your use of fertilizers, pesticides, and herbicides. If you use these chemicals, follow directions and use them sparingly. Don’t fertilize before a rainstorm. Consider using organic fertilizers. Let your lawn go golden brown in the summer months; it will rebound in the fall. Compost or mulch lawn clippings. Preserve existing trees or plant new ones—trees hold rainfall and help manage stormwater. 
  •  Replace part of your lawn with native, drought-resistant plants. Add compost to planting soil and  mulch it to improve plant growth and reduce stormwater runoff. 
  • Pick up after your pets and dispose of waste properly. Keep pets and livestock out of streams. Compost manure in a designated area so that it doesn’t wash off into nearby waterways. 
  • Reduce impervious surfaces at home and increase the vegetated land cover of your property. Impervious surfaces include your roof, driveway, and patios. Reduce rooftop runoff by directing your downspouts to vegetated areas, and not to the storm drain on your street. For your driveway and patios, consider putting in permeable paving or patterns of cement and brick that allow water to filter through them. 
  • Support your local storm- or surface-water program. Educate yourself and your family about your local watershed. Consider volunteering for stream restoration or other local volunteer projects.
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