What is “non-point” source pollution?
Non-point 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, finally depositing them into lakes, rivers, wetlands, coastal waters, and even our underground sources of drinking water.
Non-point source pollution comes from various land use practices, air pollutants, and sewer overflows — plus daily human activity. It is harder to control non-point sources of pollution. An example includes excess farm and lawn nutrients moving throughout the soil and into the groundwater, or the pollutants enter local waters directly through runoff during heavy rains, causing dangerous algal blooms.
