Since the formation of the Environmental Protection Agency and the passage of the Clean Water Act, great strides have been made toward maintaining and restoring water quality throughout the United States. This has been accomplished through regulating point sources of pollution, such as smokestacks and sewage discharge. But a more diffuse source of pollution — nonpoint source (NPS) pollution — threatens Louisiana’s ecosystems.
 
Many of Louisiana’s water resources are especially susceptible to pollution because of our unique geology and climate. Louisiana residents obtain much of their drinking water from groundwater supplies. Groundwater often lies near the surface, covered by porous limestone and sandy soils, both of which allow water to infiltrate rapidly. Dissolved pollutants reach groundwater through a process called leaching. These impurities affect the quality of our drinking water. Heavy rainfall, typical during Louisiana’s rainy season, is a major cause of leaching and stormwater runoff. Surface waters in Louisiana such as lakes, streams, rivers and estuaries are very sensitive to even small amounts of pollution.