What is Nonpoint Source Pollution?

Nonpoint source (NPS) pollution, unlike pollution from industrial and sewage treatment plants, comes from many diffuse sources. NPS pollution is caused by rainfall or snowmelt moving over and through the ground. As the runoff moves, it picks up and carries away natural and human-made pollutants depositing them into lakes, rivers, wetlands, coastal waters, and underground sources of drinking water. These pollutants include:

• Excess fertilizers, herbicides, and insecticides from agricultural lands and residential areas;
• Oil, grease, and toxic chemicals from urban runoff and energy production;
• Sediment from improperly managed construction sites, crop and forest lands, and eroding stream banks;
• Salt from irrigation practices and acid drainage from abandoned mines;
• Bacteria and nutrients from livestock, pet wastes, and faulty septic systems;

The United States has made tremendous advances in the past 25 years in cleaning up the aquatic environment by controlling pollution from industries and sewage treatment plants. However nonpoint source (NPS) pollution remains the Nation's largest source of water quality problems resulting in approximately 40 percent of our rivers, lakes, and estuaries not clean enough to meet designated uses such as fishing or swimming.

NPS pollution is widespread because it occur any time activities disturb the land or water. Agriculture, forestry, grazing, septic systems, recreational boating, urban runoff, construction, physical changes to stream channels, and habitat degradation are potential sources of NPS pollution. Activities around our yards in residential areas can contribute to NPS pollution problems.

The latest National Water Quality Inventory indicates that agriculture is the leading contributor to water quality impairments, degrading 60 percent of the impaired river miles and half of the impaired lake acreage surveyed by states, territories, and tribes. Runoff from urban areas is the largest source of water quality impairments to surveyed estuaries (areas near the coast where sea water mixes with freshwater).

• How We Can Help
• Nonpoint Source Pollution - Progress
• Water Quality Monitoring Activities

How We Can Help

We can all work together to reduce and prevent nonpoint source pollution. Some activities are federal responsibilities, such as ensuring that federal lands are properly managed to reduce soil erosion. Some are state responsibilities, for example, developing legislation to govern mining and logging, and to protect groundwater. Others are best handled locally, such as by zoning or erosion control ordinances. And each individual can play an important role by practicing conservation and by changing certain everyday habits.

• Urban Runoff
  • Keep litter, pet wastes, leaves, and debris out of street gutters and storm drains - these outlets drain directly into lakes, streams, rivers, and wetlands.
  • Apply lawn and garden chemicals sparingly and according to directions.
  • Dispose of used oil, antifreeze, paints, and other household chemicals properly, not in storm sewers or drains. If your community does not already have a program for collecting household hazardous wastes, ask your local government to establish one.
  • Clean up spilled brake fluid, oil, grease, and antifreeze. Do not hose them into the street where they can eventually reach local streams and lakes.
  • Control soil erosion on your property by planting ground cover and stabilizing erosion-prone areas.
    Encourage local government officials to develop construction erosion/sediment control ordinances in your community.
  • Have your septic system inspected and pumped, at a minimum, every 3-5 years so that it operates properly.
  • Purchase household detergents and cleaners that are low in phosphorous to reduce the amount of nutrients discharged into our lakes, streams and coastal waters.
• Agriculture
  • Protect drinking water by using less pesticides and fertilizers.
  • Reduce soil erosion by using conservation practices and other applicable best management practices.
  • Use planned grazing systems on pasture and rangeland.
  • Dispose of pesticides, containers, and tanks in an approved manner.
• Forestry
  • Use proper logging and erosion control practices on your forest lands by ensuring proper construction, maintenance, and closure of logging roads and skid trails.
  • Report questionable logging practices to state and federal forestry and state water quality agencies.

Source: U.S. Environmental Protection Agency, "Polluted Runoff (Nonpoint Source Pollution)," http://www.epa.gov 

Nonpoint Source Pollution - Progress

During the last 10 years, our country has made significant progress in addressing nonpoint source pollution. At the federal level, recent NPS control programs include the Nonpoint Source Management Program established by the 1987 Clean Water Act Amendments and the Coastal Nonpoint Pollution Program established by the 1990 Coastal Zone Act Reauthorization Amendments.

In addition, public and private groups have developed and used pollution prevention and pollution reduction initiatives and NPS pollution controls, known as management measures, to clean up our water efficiently. Water quality monitoring and environmental education activities supported by government agencies, tribes, industry, volunteer groups, and schools have provided information about NPS pollution and have helped to determine the effectiveness of management techniques.

Also, use of the watershed approach has helped communities address water quality problems caused by NPS pollution. The watershed approach looks at the water bodies and the entire area that drains into it. This allows a holistic approach to watershed stewardship.

Local citizens are participating in water conservation techniques, stream clean ups and monitoring and other environmental activities sponsored by community-based organizations. Local state, federal and university agents are working with communities to restore and maintain water quality.

Related Publications

• Watershed Approach Framework, EPA840-S-96-001;
•  Managing Source NPS News-Notes, EPA-841-N-92-003;
• The Quality of Our Nation's Water: 1994, EPA-841-S-95-004;

Source: U.S. Environmental Protection Agency, "Nonpoint Source Pollution: The Nation's Largest Water Quality Problem, Pointer No. 1," EPA841-F-96-004A, http://www.epa.gov/owow/nps/prevent.html

Water Quality Monitoring Activities

Index | Agriculture | Non-Ag Activities | Recreation | NPS | Plants & Animals | Water Quality
Physical | Hydrology | Drinking Water | Curriculum | Youth Activities

Elk River | James River | Sac River | Spring River | North Fork Salt River

Missouri Department
of Natural Resources

Missouri Watershed Information Network (MoWIN)
Send comments to: mowin1@missouri.edu
205 Agricultural Engineering
Columbia, MO 65211
Phone: (573) 882-0085
Toll Free: (MO only): 1-877-H20-shed (426-7433)
Fax: (573) 884-5650

Page last updated August 26, 2008