Water Quality

The Clean Water Act has been credited with greatly improving the condition of the waters in the United States. This success comes largely from the control of pollutant discharges from industrial facilities and wastewater treatment plants, known as "point" sources of pollution. Despite this progress, many waters still do not meet water quality standards. Of particular concern are "nonpoint" sources of pollution-diffuse sources that include various land-based activities, such as timber harvesting, agriculture, and urban development--which are widely considered to be major contributors to the nation's remaining water quality problems. The ability to deal with these problems cost-effectively depends on states' efforts to monitor their waters to identify their most serious problems and to develop strategies to address them. States send a list to the Environmental Protection Agency that identifies waters that fail to meet water quality standards and develop total maximum daily loads (TMDL) for waters on their lists. TMDLs are intended to help restore water quality by reducing the amount of pollution entering a body of water to a level that will enable it to meet the standards. This testimony discusses (1) the adequacy of the data for identifying waters for states' lists, (2) the adequacy of data for developing TMDLs for those waters, and (3) the key factors that affect the ability of states to develop TMDLs.

GAO noted that: (1) only 6 of the 50 states responding to GAO's nationwide survey indicated that they have a majority of the data needed to fully assess their waters, raising questions as to whether states' 303(d) lists accurately reflect the extent of pollution problems in the nation's waters; (2) while the state officials GAO interviewed feel confident that they have identified most of their serious water quality problems, several acknowledged that they would find additional problems with more monitoring; (3) states reported that they have much more of the data they need to develop TMDLs for pollution problems caused by point sources than by nonpoint sources; (4) states can more readily identify and measure point sources of pollution because these sources generally discharge pollutants through distinct points, such as pipes; (5) conversely, nonpoint sources are difficult to identify and measure because of their diffuse nature; (6) as a result, developing TMDLs for pollution problems caused by nonpoint sources often requires additional data collection and analysis; (7) only three states reported having a majority of the data they need to develop TMDLs for these types of problems; (8) states reported that they have been developing TMDLs for waters polluted by point sources for many years and, therefore, have expertise in analyzing these types of pollution problems; (9) in contrast, however, states told GAO that their ability to develop TMDLs for nonpoint sources is limited by a number of factors; (10) states overwhelmingly cited shortages in funding and staff as the major limitation to carrying out their responsibilities, including developing TMDLs; and (11) in addition, states reported TMDLs for the more complex, nonpoint sources of pollution.