United States . Environmental Protection Agency Office of Water (WH-556F) EPA840-F-93-001b July 1993 4>EPA The Problem of Nonpoint Source Pollution In the past twenty years, the Nation has made great strides in improving the quality of our waters. We can be proud that we are able to swim and fish in waters that just two decades ago were too polluted for these activities. Improvements have come as a result of a significant public and private investment to control "point sources" of pollution, largely from industry and municipalities. Unfortunately, water quality problems remain. Eight to 21 percent of our surface waters still do not meet the uses for which the states have designated them, e.g., fishing, swimming, drinking. Another 19 to 25 percent of these waters only partially support their designated uses. The states report to EPA every two years on the quality of the Nation's waters. These reports are compiled into the "National Water Quality Inventory." The most recent reports show that the leading cause of our water quality problems is nonpoint source pollution. Nonpoint source pollution, or polluted runoff, is the result of many different human activities that take place over a wide, geographic area. - Pollutants from these activities are carried into our surface and ground waters through rainfall, thunderstorms and snow melt, as well as through man-made runoff from irrigation and drainage. Runoff from agricultural lands is the leading cause of nonpoint source pollution and affects between 50 and 70 percent of our im- paired surface waters. Impaired waters are those that do not meet the uses for which the states have designated them. The primary agricultural nonpoint source pollutants are sediments, nutrients (nitrogen and phosphorus), animal wastes, pesticides, and salts. Pollutants enter surface water through direct surface runoff or through seepage to ground water that discharges into surface water. Of the agricultural pollutants, siltation is the most common cause of impaired streams and rivers. Suspended solids result in turbidity, reduce sunlight available to aquatic plants, cover fish spawning areas and food supplies, clog filter feeders, and harm fish gills. It is caused by erosion from farm and grazing lands, forested areas, development, and other sources. Nutrients, from the runoff of excess fertilizers and from animal wastes, are the second most common cause for impairment. Nutrients can stimulate the growth of algae, using up oxygen in the water that would otherwise be available for fish, plants, and other aquatic life. Animal wastes also contribute bacteria which can kill fish and threaten human health. Some agricultural practices may also result in the loss of wetlands and damage to riparian areas, increasing the problems of nonpoint source pollution because these areas act as natural filters. Non-agricultural sources of nonpoint source pollution include runoff from construc- tion, land development, forestry operations, and abandoned mines, as well as hydromodification. Urban runoff contains pollutants (sediments, road salts, oily residues, nutrients, and toxics) from city streets, paved areas, and lawns. Sediments constitute the largest mass of pollutants from urban areas. Urban runoff affects between five and 15 percent of surface waters. Recycled/Recyclable Printed with Soy/Canola Ink on paper that contains at least 50% recycled fiber ------- The construction of highways, roads, and land development projects produces sediments and toxic materials that degrade water quality and permanently modify fishery and wildlife habitat. Timber cutting and other forestry- operations affect approximately five percent of surface waters. Logging roads and deforested lands produce large amounts of sediments that eventually end up in streams, rivers, and lakes. In addition, many types of plants and wildlife can be affected by the loss of their habitat. Hydromodification, a result of flood control and stream channelization projects as well as reservoirs and dams, affects runoff, increases sediment deposits, and changes water quality and fishery habitats. It also increases treatment costs for water intended for human consumption and industrial use. Poor water quality costs us billions of dollars annually. It increases our costs for the treatment of drinking water, limits the produc- tivity of our fisheries, and reduces our recre- ational opportunities. In Iowa, sediments are the leading pollutant in surface waters. Iowa's Department of Natural Resources reports that sediment problems alone cost lowans approxi- mately $32 million every year in damages to recreation, fish and wildlife resources, munici- pal water supplies, transportation, and blocked drainage on agricultural lands. The remaining problems of water quality will be addressed most effectively at the state and local level. There are two and one-half million farming operations alone in the country. Cost-effective solutions can vary widely, and may even vary from one section of a single farm to another; solutions must be adaptable over time to respond to changing physical, economic, and social conditions at the local level. Many members of Congress and advocacy groups are concerned that the nation has been too slow in dealing with polluted runoff. We have known about the problem since the earliest days of our water pollution control efforts. Industry and municipalities are also concerned that their substantial investment in cleaner water is being jeopardized by the problems of nonpoint source pollution. Many industries are beginning to ask why more stringent restrictions should be placed on their effluent when the sources that are now respon- sible for the majority of water quality impair- ments have very few or no restrictions placed on them. One approach to solving the problem of nonpoint source pollution can be found in the Coastal Zone Act Reauthorization Amendments of 1990. (See related fact sheet EPA 840-F-93- OOlc) Through this law, Congress requires states with coastal zone management programs to adopt coastal nonpoint source programs. These programs can be tailored to the particular needs and problems within the state, but must have "enforceable policies and mechanisms." This is one of several approaches that are being explored by members of Congress as they consider how to improve our Nation's ability to successfully address nonpoint source pollution. ------- |