Watershed Management Bureau

  Watershed Assistance Section

   What is Nonpoint Source Pollution?

Nonpoint source pollution occurs when rainfall, snowmelt, or irrigation runs over land or through the ground, picks up pollutants, and deposits them into rivers, lakes, and coastal waters or introduces them into the groundwater.  These pollutants can include oil and sand from roadways, agricultural chemicals from farmland, sediments from construction sties, crop and forest lands, and eroding streambanks, and nutrients and toxic materials from urban and suburban areas. 

The effects of nonpoint source pollutants on specific waters vary and may not always be fully assessed.  However, we know that these pollutants have harmful effects on drinking water supplies, recreation, fisheries, and wildlife.

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. 

For more information about nonpoint source pollution, contact the Watershed Assistance Section at nps@des.state.nh.us.