Federal regulations (40 CFR Part 131) provide for a mechanism to determine those waterbodies where achievement of the Clean Water Act goals of fishable/swimmable may not be attainable. These regulations require completion of a Use Attainability Analysis (UAA). A UAA can be used by states or authorized tribes to justify changes to their water quality standards by assessing the physical, chemical, biological, economic, or other factors affecting attainment of the designated use. The UAA describes the scientific attributes of the waterbody, both natural conditions and conditions resulting from human interaction. If the attributes of the waterbody make attaining the use impossible, or if there are economic reasons why the use cannot be attained, the UAA can be used to clearly document these reasons. Finally, the UAA describes how the proposed standards will protect attainable uses.

HydroQual can assist states and tribes in the development of a UAA through:

• Identification and compilation of data resources and needs
• Design of field and monitoring programs (including such elements as routine water chemistry, sediment quality, pelagic and benthic biological surveys, and shoreline characterization)
• Identification and application of appropriate watershed/sewershed and receiving water models
• Stakeholder meetings and public outreach
• Development of technical, economic, public and regulatory support for prioritizing and expediting implementation of projects and actions needed to attain the defined goals
• Identification and development of the applicable UAA criteria required by federal and state regulations
• Providing the technical, scientific and economic bases to support the regulatory process needed to define water quality standards for the highest reasonably-attainable use