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Draft Policy Issued to Help Improve Managementof the Nation’s Sewage Treatment Facilities

Release Date: 11/03/2003
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*** Update: On May 19, 2005, we announced that we are not going to finalize the draft policy described below. ***

Cathy Milbourn 202-564-7824 /

(11/03/03) A proposed policy is being issued today that provides guidance to help local governments operate their sewage treatment facilities and to help prevent the overflow of raw sewage into homes and waterways during heavy rain storms. Many municipalities experience problems managing high volumes of wastewater coming into sewage treatment facilities during heavy rains. These high water flows can damage sensitive parts of the treatment system and lead to increased pollution of the nation’s rivers, lakes and coastal waters. The Agency believes the proposed policy will provide practical solutions to local governments while maintaining and improving water quality.

G. Tracy Mehan, III, Assistant Administrator for Water, said, “This policy will provide a consistent set of principles to guide local sewage treatment facilities in managing wet-weather events. We are working with these facilities to prevent backups of sewage in homes and the environment while requiring all discharges to meet Clean Water Act permit limits.”

The draft policy focuses on the practice of blending which occurs when large volumes of wastewater, caused by heavy rainfall or snowmelt, exceed the capacity of the secondary (biological) treatment units at a sewage treatment facility. During a storm, the incoming wastewater is treated by the primary units and then sent to the secondary treatment units. Amounts in excess of the capacity of the secondary units are diverted around and then later recombined or blended with the wastewater that has been treated by the secondary units. These blended flows are disinfected and discharged.

Larry Jaworski, President of the Water Environment Federation said, “The Water Environment Federation is pleased that EPA is providing national guidance on blending at municipal wastewater treatment plants during wet weather. Blending is a long-standing, 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.”

This proposed policy will help to clarify the requirements of the Clean Water Act and applicable regulations on the practice of blending and requires that municipal sewage treatment facilities implement safeguards, including enhanced monitoring. The policy emphasizes the requirement that every sewage treatment facility in the United States must maintain compliance with the Clean Water Act. The policy also strongly encourages states that have not already done so to adopt EPA’s 1986 water quality criteria for pathogens and to ensure that blending is addressed in the permitting process.

The public is invited to comment on the draft policy until Jan. 9, 2004. The draft policy and instructions for submitting comments are available at: .