(November 6, 2018) - NACWA provided written comments to EPA on October 31 regarding the Agency’s development of a proposed rule on peak wet weather flow blending. The comments emphasized the public health and environmental benefits of treating all wet weather flows at the treatment plant with blending and reducing upstream overflows and basement backups. 

EPA had asked for written comments as part of its process to collect public input on the rulemaking, which the Agency announced in April.  EPA also held a blending Stakeholder Roundtable on October 15 and three public listening sessions to gather input.

In its comments, NACWA urged EPA to ensure that any action the Agency takes on peak wet weather flow blending be consistent with the 2013 8^th Circuit Court of Appeals decision in Iowa League of Cities v. EPA.  NACWA asked that EPA do this by recognizing two principles: (1) Blending is not a bypass when it is part of the designed operation of the treatment plant, protects the biological treatment processes, and is designed to meet all discharge permit limits; and (2) compliance with all permit requirements is determined at the final discharge point, and not at any point within the treatment plant.  Clarification of these two principles would provide the certainty needed for publicly owned treatment works (POTWs) to invest in peak flow treatment improvements.

NACWA asked that EPA allow states and permit writers to determine the conditions for blending that are appropriate for their state and for individual POTWs.  NACWA also recommended that EPA allow flexibility to account for the fact that every treatment plant and community is different.  Because of this, the frequency of blending, the inflow and infiltration reduction programs, and the monitoring programs of each utility will need to be different. 

Representatives from seven NACWA public member agencies participated in the October 15 EPA Stakeholder Roundtable on peak wet weather flow blending, with additional representatives attending as observers.  The Agency held the invitation-only Roundtable to gather input for developing a proposed rule on blending. 

NACWA will continue to work with its Blending Workgroup to provide input to EPA as the rulemaking process unfolds. Please contact Cynthia Finley, NACWA’s Director of Regulatory Affairs, with any questions or to join the workgroup.