May 17, 2022

The Mixed Up World of Blending

Posted on May 17, 2022 by Ed Tormey

Recently I read a news release that the U.S. Eighth Circuit Court of Appeals had issued a mandamus order against the U.S. EPA.  Mandamus order?  My mind went back to law school and Marbury v. Madison, which may have been the last time I read a case discussing mandamus relief.  So what happened? A brief discussion of the underlying 2013 case, Iowa League of Cities v. EPA, 711 F.3d 844, is in order [2013 Iowa League of Cities Case]. In that case Senator Charles Grassley had written letters to U.S. EPA seeking clarification on the agency’s position on bacteria mixing zones and wet weather blending[1] under the Clean Water Act.  For the Eighth Circuit, U.S. EPA’s responses to those letters were problematic. The court determined that those responses constituted legislative rules violating the APA’s requirement for notice and comment procedures.  The court went ahead and further rendered its opinion on the merits of U.S. EPA’s position on blending.  The court vacated U.S. EPA’s “rule” – imposing secondary treatment requirements on flows within a facility – as exceeding the agency’s legal authority under the Clean Water Act.   In essence the court determined that the agency’s authority originated “at the end of the pipe” and not within a facility’s internal secondary treatment process. 

In its own right this 2013 case was an eye opener.  Responses to letters constituting legislative “rules” was certainly noteworthy as was the court’s decision to forego remand on the APA violations concerning the blending “rule” and, instead, rendering a decision on the merits.   For the court, there was no way U.S. EPA could justify any rule that regulated the internal workings of a plant’s treatment processes.  Hence, there was no reason to postpone the court’s decision that regulating blending exceeded U.S. EPA’s statutory authority. 

So what caused the court to issue a mandamus order on December 22, 2021 [2021 Iowa League of Cities Case]? The original petitioner sought relief from the court because it asserted that U.S. EPA was still regulating wet weather blending in the Eighth Circuit (and nationwide), this time related to combined sewer systems.  The court agreed stating that “EPA continues to regulate blending as a prohibited bypass in the Eighth Circuit, albeit for combined sewer systems only” and granted petitioner’s request for mandamus relief.  The court did deny petitioner’s request for a nationwide mandate against U.S. EPA for its blending position, limiting its decision to the Eighth Circuit only. 

The Eighth Circuit’s most recent order is the latest action in a long-running debate on how to regulate wet weather blending in the United States.  And the problem is not going away.  With many areas of the United States experiencing record rainfalls, how should we regulate peak flows coming into a wastewater treatment plant? 

U.S. EPA has made clear its position that it can regulate blending outside the Eighth Circuit (Arkansas, Iowa, Minnesota, Missouri, Nebraska, North Dakota, and South Dakota) [Center for Regulatory Reasonableness v Environmental Protection Agency]. U.S. EPA even began work on a new blending rule in 2018, taking public comment and holding a series of public meetings ahead of issuing a proposal.  But no proposal came.  The Biden administration has included a “peak flows management” rulemaking in its list of “long-term actions” in the Fall 2021 Unified Agenda of regulatory actions, but no date has been set for such a rule proposal [Fall 2021 Unified Agenda]. In the meantime new wastewater treatment plants are being designed to allow wet-weather blending, absent more guidance from U.S. EPA.  New federal Infrastructure monies will likely lead to even more of these facilities being built.  If U.S. EPA has a fundamental problem with blending it behooves them to make their position clear – and soon.  And it is safe to assume that the Eighth Circuit will weigh in once again on any such position U.S. EPA takes.    

[1] Blending is the engineered channeling of a portion of the peak wet weather flow through a non-biological treatment unit and then being “blended” or recombined with the portion of the effluent flow that went through the biological secondary process before disinfection and discharge.  The purpose of blending is to protect the biological secondary treatment system from being “washed out” during high flows.  Blended final effluent must still meet all applicable effluent limitations in the NPDES permit.   Outside the Eighth Circuit the question remains whether blending is a prohibited bypass under the Clean Water Act.  See 40 CFR §122.41(m).