Sources of Pollution

Non-point vs point source pollution

A point source is a source of water that you can clearly point to as discharging into a water body such as pipes or ditches. The legacy of pollutants from industry in the area is the result of direct discharge from a point source.

With the inception of the Clean Water Act the federal government began to regulate point sources leading to significant improvements to environmental health.

Non-point sources are now the major sources of pollutant discharge and are much harder to regulate.

Non-point sources are from water that doesn’t soak into the ground, but flows over the land during rain and snow melt events. This flow picks up and carries whatever pollutants it comes in contact with, such as oils, pesticides, fertilizers, etc. When this flow discharges into surface water it brings along with it all the pollutants it is carrying. Even temperature can be considered a non-point source pollutant picked up from hot asphalt during a summer rain.

Insert Picture: Runoff

Links:

Summary of the Clean Water Act | US EPA

Tribal Nonpoint Source Program | US EPA

Tribal Grants under Section 106 of the Clean Water Act | US EPA

Basic Information about Nonpoint Source (NPS) Pollution | US EPA