Nonpoint source(NPS) pollution is also known as runoff or diffuse pollution. Unlike pollution from industrial and sewage treatment plants, NPS pollution is caused by rainfall or snowmelt moving over and through the ground. NPS pollution is the No. 1 contributor to water pollution in Kentucky, accounting for approximately two-thirds of the water quality impairments in Kentucky’s streams and lakes. As the runoff moves, it picks up and carries pollutants, finally depositing them into lakes, rivers, wetlands, coastal waters and even underground aquifers.

While the bulk of water quality data is presented in terms of surface water, nonpoint source pollution affects all water resources: rivers, streams, lakes, wetlands and groundwater. Groundwater and surface water are often difficult, and sometimes impossible, to separate.  From sinking streams to springs to large karst rivers, groundwater and surface water are intimately linked in Kentucky.

Where do the pollutants come from?

• Urban Runoff:  Chemicals and fertilizers used on grass or in gardens, along with car emissions, oil, antifreeze, paint, battery acid, pet waste, household cleaners and other impurities can get into our water. They are carried by runoff from parking lots, driveways, lawns, through storm drains and melts, or placed on the ground by unsuspecting homeowners.
• Septic Systems:  These home treatment systems filter waste through the soil. When they are improperly maintained, or poorly located, waste may emerge at the surface where it can be washed into streams and lakes by rain, or it can seep directly into groundwater.
• Agriculture:  Tons of topsoil wash off cultivated fields in Kentucky every year and much of it ends up in streams and lakes. The problem grows when fertilizers and pesticides applied to that soil get washed into the water. Improperly managed waste from livestock also damages streams and lakes, robbing them of oxygen. 
• Forestry:  Poor logging roads and the skid trails made as timber is dragged from an area can cause erosion. Operating machinery in or near a stream can also cause erosion.
• Mining:  When mines are not properly constructed, operated or reclaimed, they cause significant NPS pollution. Sediment is washed into streams when reclamation is inadequate. The impurities in coal create acids when exposed to water and air, and these acids often wash into streams or seep into groundwater.
• Construction:  When soil is disturbed by grading work and BMPs are not properly used and maintained, sediment may enter streams, rivers and lakes through runoff. Oils, paints, cleaners and other pollutants used in construction can also damage our waters.
• Stream projects:  Dredging, channelization and other stream alteration projects damage water quality when tons of silt, rock and debris are disturbed. The debris moves into other areas of streams or lakes, smothering aquatic life and destroying aquatic habitat. 

NPS Pollution Control

Nonpoint source pollution is controlled primarily through the adoption of practical and cost-effective land management practices that are known as best management practices (BMPs). BMPs allow for everyday activities while reducing or preventing nonpoint source pollution. The use of BMPs protects water quality while maintaining the economic value of Kentucky’s land resources.

Kentucky’s approach to controlling NPS pollution includes both focused watershed projects and statewide initiatives. Watershed projects are important for reducing NPS pollution; they are designed to improve or maintain water quality conditions in watersheds through aggressive BMP implementation. Watershed projects address diverse NPS concerns, utilize a variety of funding sources for BMP implementation and include water quality monitoring as a measure of success. Statewide programs are an integral part of Kentucky’s strategy to reduce NPS pollution. Statewide programs help to raise public awareness about runoff pollution, provide technical information on BMPs and develop and implement regulatory programs. Kentucky’s NPS Pollution Control Program uses both regulatory and nonregulatory mechanisms to achieve BMP implementation in watershed projects and statewide initiatives.

Like many states, Kentucky does not have sufficient resources to implement BMPs for all existing or potential NPS pollution problems. In order to maximize NPS pollution control efforts, technical and financial assistance from other federal, state and local sources are cooperatively targeted to NPS priority watersheds.  Grant funds authorized by Section 319(h) of the Clean Water Act assist states with implementing nonpoint source pollution control projects.