Nonpoint Source Pollution
Water is one of our most important natural resources and essential to sustain life. Pollution of our water causes devastating effects that threaten both public health and the environment.
When we think of environmental pollution, we most often conjure up images of smoking factories, toxic waste dumps, and oil spills. What we don’t realize, however, is that the leading cause of water quality problems is from pollutants that don’t originate from a single source or enter waterways at a particular site.
This type of widespread pollution, called nonpoint source pollution, occurs when rainfall, snowmelt or irrigation runs over land, picks up pollutants, and deposits them into streams, rivers, lakes and groundwater. In urban areas, this most often happens when runoff from hard surfaces, such as streets, parking lots, and buildings washes pollutants into storm drains. Runoff from construction sites, if not controlled, can pick up pollutants and soil from the disturbed areas, carrying them downstream into storm drains. Unlike wastewater, which is treated before it is released, stormwater flows untreated into local waterways.