EPA Partially Approves Kentucky’s Proposed Water Quality Criteria for Selenium
The EPA has issued a final decision on the revisions to Kentucky’s water quality standards that were proposed as part of the Department of Water’s Triennial Review. Of particular interest is the EPA’s approval of the chronic water quality criteria for selenium. The change institutes a two-step process that was originally proposed by the EPA in 2004, but not implemented. The first step duplicates the old standard of testing the water column for selenium. The second step is triggered only upon a showing of selenium levels in the water column testing above 5 µg/L. This step calls for the analysis of fish tissue, either whole body or fish egg/ovary tissue, to determine compliance with the water quality standard.
The EPA disapproved Kentucky’s proposed revision, adding a second step of tissue testing, to the acute water quality criteria for selenium. 40 CFR 131.21(a)(2) requires the EPA to specify why the proposed standard does not comply with the requirements and specify the changes necessary to assure compliance. In its decision, the EPA did not specify what changes needed to be made to the standard in order to comply with regulations. The effect of the disapproval is that Kentucky’s previous acute water quality criterion of 20 µg/L in water column testing will continue to serve as the acute criterion.
The previous selenium standard in Kentucky had been enforced primarily though Clean Water Act citizen suits. This new standard will be similarly enforced in the case of citizen suits, but may have a much broader effect if the new KPDES general permit requires monitoring of selenium. The current general permit is set to expire on July 31, 2014.
The EPA’s final decision can be found here: http://water.ky.gov/Documents/11_15_2013%20Letter%20to%20Dr%20Peters.pdf