On March 25, a federal appellate court blocked EPA from using its current approach as outlined in various guidance letters to regulating wastewater treatment facilities that “blend” partially treated and fully treated effluent during storm events. The 2011 letters to Sen. Charles Grassley outlined EPA’s positions on mixing zones below treatment plants and the use of blending. The Court ruled that EPA, in effect, was using these letters in lieu of actual regulations to enforce these positions against treatment plants. EPA has indicated in the past that it was considering proposing such regulations, but has never proceeded with actual regulatory proposals.
In addition to negating EPA’s reliance on guidance to regulate blending, the appellate court also vacated the substance of EPA’s blending approach as in excess of Clean Water Act statutory authority because it would impose the effluent limitations of the secondary treatment regulations internally in the treatment plant, rather than at the point of discharge into navigable waters. This is particularly significant as this issue has been a long-standing point of contention between EPA and the regulated community.
In 2005, EPA was considering finalizing a proposed “blending” policy based on an agreement between the Natural Resources Defense Council and the National Association of Clean Water Agencies. This draft policy required treatment facilities to determine whether there were no feasible alternatives to blending before the practice received an NPDES permit. However, this policy was not finalized and EPA instead has relied on a general guidance approach now invalidated by the Court. EPA will now have to consider if and how it will restart the regulatory development process on blending.
This ruling was made by the U.S. Court of Appeals for Eighth Circuit: Iowa League of Cities v. EPA, No. 11-3412, March 25, 2013.