The state must also develop water  quality criteria, which specify pollutant limits that determine whether a  water body’s designated use is achieved. States’ Practices in Changing Designated Uses Vary Widely

We asked the states to report the total number of designated use changes  they adopted from 1997 through 2001. While some states made no use  changes, others made over 1,000 changes. EPA Assistance and Guidance Needed to Help States Make Defensible Designated Use Changes

According to responses to our survey, a key reason state officials have not  made more of the needed designated use changes is the uncertainty many  of them face over the circumstances in which use changes are acceptable  to EPA and the evidence needed to support these changes. To do this, states are  required to conduct a use attainability analysis (UAA). Forty-three percent of states reported that  they need additional clarifying UAA guidance. EPA Has Not Developed and Updated Key Criteria Documents

While EPA has developed and published criteria documents for a wide  range of pollutants, approximately 50 percent of water quality impairments  nationwide concern pollutants for which there are no national numeric  water quality criteria. 2.) States Need EPA Assistance to Establish Criteria That Can Be Compared to Reasonably Obtainable Monitoring Data

Even when EPA has developed criteria recommendations, states reported  that the criteria cannot always be used because water quality officials  sometimes cannot perform the kind of monitoring that the criteria  documents specify, particularly in terms of frequency and duration. Our  survey asked states about the extent to which they have been able to  establish criteria that can be compared with reasonably obtainable  monitoring data. We  first asked the states whether an improvement in the process of changing  designated uses would result in different water bodies being slated for  cleanup within their states, and 22 states reported affirmatively. As figure 3 shows,  when we superimposed the states’ responses to obtain the cumulative  effect of improving either designated uses or the process of criteria  modification, a total of 30 states indicated that an improvement in the  process of modifying standards (whether a change in their designated  uses, their criteria, or both) would result in different water bodies being  slated for cleanup.
Why GAO Did This Study

Water quality standards comprise designated uses and water quality criteria. These standards are critical in making accurate, scientifically based determinations about which of the nation's waters are most in need of cleanup. GAO examined the extent to which (1) states are changing designated uses when necessary, (2) EPA is assisting states toward that end, (3) EPA is updating the "criteria documents" states use to develop the pollutant limits needed to measure whether designated uses are being attained, and (4) EPA is assisting states in establishing criteria that can be compared with reasonably obtainable monitoring data.

What GAO Found

The extent to which states are changing designated uses varies considerably. Individual states made anywhere from no use changes to over 1,000 use changes during the 5-year period, from 1997 through 2001. Regardless of the number of use changes states made, nearly all states report that some water bodies within their states currently need changes to their designated uses. To do so, many states said they need additional EPA assistance to clarify the circumstances in which use changes are acceptable to EPA and the evidence needed to support those changes. While EPA has developed and published criteria for a wide range of pollutants, the agency has not updated its criteria documents to include sedimentation and other key pollutants that are causing approximately 50 percent of water quality impairments nationwide. In addition to needing new criteria documents, states need assistance from EPA in establishing criteria so that they can be compared with reasonably obtainable monitoring data. Changing either designated uses or criteria is considered a standards modification. Twenty-two states reported that an improvement in the process for changing designated uses would result in different water bodies being slated for cleanup; 22 states also reported that an improvement in the process for modifying criteria would have that effect. Collectively, 30 states would have different water bodies slated for cleanup with an improvement in the process of modifying standards.