Changes to Designated Uses and Site Specific Criteria

Designated uses assigned to particular surface waters and site-specific water quality criteria are revised on an ongoing basis. Each change to a designated use and site-specific criteria is based on a scientific evaluation, called a use attainability analysis (UAA), considers public input, and is finalized through a formal determination by the Administrator of the Water Quality Division or formal adoption in Chapter 1. Click here to view a table of the UAAs and site-specific criteria adopted in Wyoming since July 2001.

Fisheries Designated Uses and Temperature Criteria Project

In anticipation of updating Wyoming’s fisheries designated uses and associated temperature criteria, the Surface Water Quality Standards Program partnered with the University of Wyoming to have a Master’s student compile scientific literature and information on short-term and long-term temperature requirements for fish found in Wyoming streams. The student’s thesis also compiles temperature data, along with fish distribution data collected by the Wyoming Game and Fish Department and the University of Wyoming. DEQ is planning to evaluate the recommendations included in the thesis and work with the Wyoming Game and Fish Department, other partners and the public to develop recommended fisheries designated uses and associated temperature criteria. 

Recreation Designated Uses Project

Since approximately 2009, DEQ has been working with the public to develop a Categorical Use Attainability Analysis for Recreation to identify low flow channels in the state where swimming or similar water contact activities (i.e, primary contact recreation) are not attainable or existing uses. Waters not used for swimming or similar water contact activities are designated for secondary contact recreation. On September 1, 2016, the Water Quality Division Administrator made a final determination regarding the recreation designated uses changes. The designations were submitted to the United States Environmental Protection Agency pursuant to the federal Clean Water Act in November 2016. The revised designations became effective in Wyoming on February 15, 2017. On September 12, 2017, USEPA approved the designated use changes, with 10 exceptions. Recreation designations can be determined using the recreation designated uses Web Map.


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