Over a period of decades, federal laws and regulations have established a process for the Environmental Protection Agency (EPA) and states to regulate “point sources” of pollution. Point sources are generally municipal and industrial facilities that discharge pollutants via a point, such as a pipe or other conveyance, directly to a body of water. EPA and the states issue permits to these entities to put limits on the types and amounts of pollutants such facilities can discharge. These laws and regulations have helped clean up major water quality problems and reduce the amount of pollutants directly discharged into surface waters. However, many of the nation’s waters are still not meeting water quality standards. For example, toxic algae, such as Pfiesteria piscicida, which are associated with excessive amounts of nutrients (chemical elements such as nitrogen and phosphorus) in waters in Maryland, North Carolina, and Virginia, resulted in millions of fish killed and adverse human health effects. Various pollutants have also resulted in over 2,000 fish consumption advisories and more than 2,500 beach closings and advisories being issued in 1996 alone. Overall, EPA reports that over one-third of the nation’s waters that were assessed by states are still impaired. Nonpoint sources of water pollution, or diffused sources, have been identified as the primary reason for these continued problems. Nonpoint sources of water pollution include a wide array of land-based activities such as timber harvesting, grazing, urban development, and agriculture. Figure 1.1 shows many such nonpoint sources in a watershed setting. Pollution comes from these disparate sources via the process of rainwater, snowmelt, or irrigation water moving over or through land surfaces. This results in pollutants, either dissolved or solid, being transported and eventually deposited into rivers, lakes, and coastal waters or introduced into groundwater. Airborne pollutants, sometimes transported long distances and then deposited in bodies of water, are also considered a source of nonpoint pollution, as is polluted groundwater which discharges into surface water. The types of pollutants vary with the activity involved and include sediment, nutrients, pesticides, pathogens (such as bacteria and viruses), salts, oil, grease, toxic chemicals, and heavy metals. Sediment is a common pollutant from many nonpoint-generating activities and can impact water quality by contaminating drinking water sources or silting in spawning grounds for certain aquatic species. Another common group of nonpoint pollutants, nutrients, can result in excessive plant growth and subsequent decaying organic matter in water that depletes oxygen levels, thereby stressing or killing other aquatic life. Pesticides, pathogens, and other toxic substances associated with runoff from agriculture and other sources can also be hazardous to human health and aquatic life. The severity of any nonpoint impact is dependent on the amount of pollutants actually reaching a body of water and the ability of receiving waters to assimilate or transport those pollutants. Nonpoint source pollution is much more difficult to track than point source pollution. Because the sources are diffused, it is very difficult to pinpoint the exact amount of pollutants coming from individual sources, including that from natural sources of pollution, particularly for pollutants such as sediment that may result from a wide variety of activities and sources. In addition, control practices vary in their effectiveness depending on many site-specific characteristics such as soil type, topography, and climate. As a result, there is much uncertainty in quantifying nonpoint source pollution stemming from specific sources and tracking improvements resulting from control practices. The nature and extent of nonpoint source pollution is essentially a function of the way individuals use the land. Therefore, regulating these activities has been a sensitive issue since land use decisions are largely made at the local level and influenced by state policies. As a result, the Congress has left the actual control and regulation of nonpoint source pollution up to the states while addressing the importance of dealing with the problem in amendments to the Clean Water Act in 1987. Specifically, section 319 of the Clean Water Act, added in 1987, provides a limited federal role in addressing nonpoint pollution. Under this section, EPA provides federal funds and management and technical assistance to states to implement nonpoint source management programs. In their nonpoint source assessments completed in 1989, states identified waters that without additional controls over nonpoint sources, will not meet water quality standards. The states also developed management programs to deal with the problems. In addition, section 6217 of the Coastal Zone Act Reauthorization Amendments of 1990, administered jointly by EPA and the Department of Commerce’s National Oceanic and Atmospheric Administration (NOAA), outlines a more rigorous process for states to deal with nonpoint sources impacting coastal waters. Section 6217 requires states to address significant sources of nonpoint pollution from agriculture, forestry, urban areas, marinas, and hydromodification. This program differs markedly from section 319 in that states are required to include in their programs enforceable policies and mechanisms to ensure that management measures to address these sources are implemented. In addition to section 319’s explicit authorization of a federal role, other agencies are authorized to encourage more environmentally sensitive land use practices. For example, some federal programs use a voluntary cost-share approach with private landowners to encourage improved land use actions, particularly with regard to controlling soil erosion and improving agricultural practices. The Clean Water Act acknowledges that federal agencies are also potential sources of nonpoint pollution via their facilities or activities, or those issued permits or licenses by them, such as grazing and timber harvesting. Therefore, the act includes provisions whereby federal agencies are to ensure that their activities are “consistent” with state nonpoint source pollution management programs. States can judgmentally review certain federal projects and activities to determine whether they conflict with the states’ nonpoint management programs. In accordance with procedures outlined in an executive order regarding intergovernmental review of federal programs, federal agencies are required to consult with the states and make efforts to accommodate their concerns or explain their decisions not to do so. In February 1998, the administration proposed a new plan to address the nation’s remaining water quality problems. Among the “Clean Water Action Plan’s” primary goals are to provide new resources to communities to control nonpoint source pollution, strengthen public health protection, and encourage community-based watershed protection at high-priority areas. The Action Plan also recognizes the role that federal land management agencies must play in protecting the water resources on their lands as well as federal agencies’ roles in providing technical and financial assistance to states and private entities to better deal with nonpoint source pollution. The Chairman, Subcommittee on Water Resources and Environment, House Committee on Transportation and Infrastructure, asked us to (1) provide background information and funding levels for federal programs that primarily address nonpoint source pollution (i.e., those programs identified as either focusing primarily on nonpoint source pollution or that devote at least $10 million annually to the problem); (2) examine the way EPA assesses the overall potential costs of reducing nonpoint source pollution nationwide and alternative methods for doing so; and (3) describe nonpoint source pollution from federal facilities, lands, and activities that federal agencies manage or authorize, or for which they issue permits or licenses. To address the first objective, we surveyed agencies to obtain information on program purpose, key goals and objectives, program funding and staffing levels, matching requirements, and opinions on the potential impact of the Clean Water Action Plan. For relevant Clean Water Act sections, we also included additional questions about how EPA allocates funds across projects, regions, and states. We pretested our survey with officials in the U.S. Department of Agriculture (USDA), EPA, the Fish and Wildlife Service, and the Army Corps of Engineers. In order to identify the most important nonpoint source pollution programs, we asked agencies to respond to our survey for programs meeting at least one of the following two criteria: (1) program expenditures addressing nonpoint source pollution exceeded $10 million for at least 1 year during fiscal years 1994 through 1998 or (2) the program primarily addressed nonpoint source pollution regardless of program expenditures. We sent survey instruments to over 100 programs that we identified through our prior reports and agency background information and discussions with agency officials at EPA; NOAA; and the Departments of Agriculture, Defense, Energy, Interior, and Transportation. The response rate for our survey was 100 percent. For the second objective, we reviewed EPA’s nonpoint source pollution component of the Needs Survey, examining the analytical structure of the models, the reasonableness of key assumptions, and the completeness of data using standard economic and statistical principles. We also interviewed EPA officials and contractor staff responsible for developing and using the models and requested model documentation. We interviewed EPA staff involved with the 1996 report as well as staff working on the report to be issued in 2000. We consulted with experts in water quality modeling from EPA, USDA’s Natural Resources Conservation Service and the Economic Research Service, and Interior’s U.S. Geological Survey. We also reviewed pertinent scientific literature to help identify alternative methodologies for a conceptual framework for estimating nationwide control costs. For the third objective, we identified the primary federal agencies that manage or authorize, or issue permits or licenses for, activities or facilities that result in nonpoint source pollution by interviewing officials at EPA; the Army Corps of Engineers; the Federal Energy Regulatory Commission; and the Departments of Agriculture, Defense, Energy, Interior, and Transportation. We limited our investigation into nonpoint source pollution-generating activities to those that are not regulated under EPA’s point source or stormwater permit requirements. For example, we excluded sources such as construction sites larger than 5 acres or certain industrial activities that must comply with stormwater runoff requirements to address nonpoint source pollution. Because quantitative data on federal agencies’ nonpoint source pollution contribution generally do not exist, we developed an array of other indicators to help characterize agencies’ possible contributions. The primary factors were the extent of agency involvement in nonpoint source-generating activities, the types of impacts that result from the activities, circumstances that may influence the impacts, and management practices that can minimize the impacts.