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Water: Use Attainability Analysis

Basic Information: Introduction to UAAs


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Setting water quality goals through assigning "designated uses" is best viewed as a process for states and tribes to review and revise over time rather than as a one-time exercise. A key concept in assigning designated uses is "attainability," or the ability to achieve water quality goals under a given set of natural, human-caused, and economic conditions. The overall success of pollution control efforts depends on a reliable set of underlying designated uses in water quality standards.

In recognition of the strong role that designated uses have in driving monitoring, assessments, Total Maximum Daily Loads (TMDLs), and permits, EPA has been promoting public dialogue on designated uses and UAAs. In 2002, EPA held a Designated Use Symposium. Participants generally agreed that it is important to have the right uses designated to each waterbody segment, and we also learned that states needed to invest in putting in place more refined use designations along with differentiated criteria to protect those uses. From this symposium, we realized that states and EPA need a credible and efficient process for making use decisions in a timely manner that allows progress toward the best water quality possible. After making designated uses a priority, we issued our Plan for Supporting States and Tribes on Designated Use Issues in 2004, which called for:

  • More outreach, training, workshops, and other support for states and tribes on critical issues regarding designating appropriate uses; and
  • Continued discussions with stakeholders on designated use issues.

Between February 2005 and April 2006, EPA has facilitated several workshops with our state, inter-state, and tribal partners. EPA Regional Offices have been heavily involved and invested in these efforts. We have heard about some innovative and successful approaches, as well as some common frustrations. In addition, EPA has co-sponsored multi-stakeholder public meetings to obtain views from interested parties. Overall, we heard a desire to reduce debate and to make progress toward reaching attainable goals. We heard a desire for EPA to provide more precise and specific answers to what are in some cases some pretty generic questions about how we interpret certain provisions of our regulations.

Over the course of implementing the WQS program, many designated use changes have occurred as a result of informative and compelling demonstrations provided by UAAs. The enclosed case studies display the breadth and variety of UAAs. In some cases, such as the one provided for Chesapeake Bay, the UAA is extensive and resource-intensive. However, we have also seen effective UAAs that are much simpler, for example by conveying the appropriate designated use expectations principally through a set of photographs documenting the physical characteristics of the waterbody.

The most significant misperception about designated uses and UAAs is that UAAs need only address the current condition of a waterbody: that a designated use may be removed simply by documenting that protective criteria are exceeded. However, it is the prospective analysis of future attainability of designated uses that provides the demonstration necessary to support a use change. A related misconception is that UAAs are only a means to remove a designated use. In fact, UAAs have supported both removing uses and adding uses. The program experience and future direction reflects a growing practice of "sub-categorizing" or "refining" designated uses; that is, making them more specific and precise as opposed to removing them.

Often, we are confronted with the fundamental question of why we should promote refining designated uses, particularly if the current designated uses are "fishable/swimmable." Our intent is to help the public act to improve water quality. We believe that setting attainable water quality goals is important in stimulating action to improve water quality. We do not believe that setting unattainable uses advances actions to improve water quality.

The WQS program is intended to protect and improve water quality beyond what is provided for through technology controls under the effluent guidelines program. WQS are supposed to guide actions to reduce pollutant releases regulated under the CWA. WQS are supposed to help us decide what needs to be done. The reality is that as more assessments are being done and TMDLs are being contemplated, we are facing attainability questions with current standards. This is in part related to the evolution of the WQS Program; in the early days, use attainability analyses were not usually performed when uses were originally designated. We are encountering more difficult issues, such as how to address the recreational use issue during wet weather events (CSOs) and how to address aquatic life uses in effluent dependent and ephemeral waters. These attainability questions can contribute to delays in achieving pollutant reductions (especially for nonpoint source control) because people often believe that the water quality goals are incorrect and perceive that revising WQS is a complex process. This is why we have been investigating the best ways to utilize UAAs and related tools, like variances, to make progress in getting designated uses right.

Many of our waters do not meet the water quality goals envisioned by the Clean Water Act. Many of the problems have been produced over many years and may take many years to resolve. Some problems may take substantial changes in resource management to implement solutions. A process of setting incremental water goals through refined designated uses, that in turn advances progress toward an ultimate goal, can help us achieve our long term goals faster. One way to achieve efficiency in the process of assigning attainable designated uses is to better synchronize UAA analyses with the TMDL process. In practice, UAAs may be conducted prior to, concurrently with, or after the development and implementation of a TMDL. In many cases, the data generated during a TMDL could well serve as the foundation for deciding whether a change in a use is warranted.

Finally, whenever we contemplate a use change, there should be thoughtful and informed public involvement in the process and throughout the process. States should communicate to the public about use changes early in the process and EPA should publicly support the states' actions to engage the local community in these discussions of what is attainable. These are important decisions, and the best decisions reflect consideration of all perspectives.

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