The Water Environment Federation (WEF) recently issued a statement asserting its approval of the release of the EPA's draft guidance on blending.
"The Federation is pleased that EPA is providing national guidance on blending at municipal wastewater treatment plants during wet weather," said WEF president Lawrence P. Jaworski. "Blending is a longstanding, sensible practice used to manage high flow events at wastewater treatment plants while maintaining compliance with NPDES Permit limits. EPA's guidance will support local governments in planning and operating wastewater facilities which provide environmentally sound and cost effective treatment during a variety of conditions, leading to improvements in water quality."
The majority of Publicly Owned Treatment Works (POTWs) in the United States today are biological systems designed to adjust to average daily loads and flows. The current systems are not technically capable of effectively treating high quantity/low concentration flows during peak wet weather, which results in lower treatment efficiencies.
WEF supports approaches that maximize the cost effective treatment of wastewater flows and has encouraged EPA to interpret Clean Water Act requirements to allow for maximum treatment, including a blending alternative nationally accepted and consistently applied and enforced. The proposed guidance will likely support POTWs in maximizing use of treatment facilities to provide a higher level of treatment for more flow and improve the quality of effluent.
The Federation appreciates the efforts of the U.S. EPA's Office of Water and EPA Regions in developing national blending guidance and while WEF endorses the blending policy in concept, the Federation will submit detailed comments to EPA on the draft guidance and its implementation. "Implementation of this guidance will depend on use of best practices for treatment plant planning, design, construction and operation. WEF looks forward to working with EPA in articulating these practices and ensuring that they are understood by all involved," added Jaworski.
Founded in 1928, the Water Environment Federation (WEF) is a not-for-profit technical and educational organization with members from varied disciplines who work toward the WEF vision of preservation and enhancement of the global water environment. The WEF network includes water quality professionals from 79 Member Associations in over 30 countries.