EPA Proposes Policy For Wet Weather Discharges At Wastewater Treatment Plants

EPA has proposed a new policy for addressing peak wet weather discharges at wastewater treatment plants.

The proposal, an alternative to an earlier plan criticized by environmental groups, is based upon a negotiated agreement on the issue of peak wet weather flow management reached by the Natural Resources Defense Council (NRDC) and the National Association of Clean Water Agencies (NACWA). The two organizations presented the plan to the agency in October after EPA encouraged them to work to address the problem.

"Our peak flow policy puts a premium on stopping leaks and spills, improving treatment, and increasing public oversight," said Benjamin Grumbles, EPA's assistant administrator for the Office of Water. "I commend environmentalists and utilities for working to find common ground on a clean water solution that doesn't rely on dilution."

Across the country, many municipal wastewater treatment systems experience problems during heavy rain downpours (peak wet weather), when flows to the wastewater treatment plants exceed the plant's biological treatment capacity. During peak wet weather, limited diversions around biological treatment units can help prevent raw sewage from being discharged into the nation's waters, backing up into homes and other buildings, or damaging biological treatment units.

EPA's goal in proposing this new policy is to ensure that all feasible solutions are used by local governments when addressing problems related to peak wet weather and to improve treatment of wastewater to protect human health and the environment.

The policy encourages public participation via the National Pollutant Discharge Elimination System (NPDES) permit process, and provides for public notification in the event that a diversion does take place.

The policy states that in limited situations, a NPDES permit can approve anticipated diversions around biological treatment units, provided the facility demonstrates that there are no feasible alternatives and that diverted flows receive a minimum of primary treatment. The policy also confirms that end-of-pipe discharges must comply with Clean Water Act permits, including effluent limitations based on secondary treatment and any more stringent limitations for receiving waters.

With the proposal EPA anticipates that over time the need for wet weather flow diversions can be eliminated from most treatment plants serving sanitary sewer collection systems. That can happen through various approaches such as enhancing storage and treatment capacity and reducing sources of peak wet weather flow volume.

NACWA's Executive Director, Ken Kirk said, "EPA's release demonstrates that sound policy can result when organizations stay focused on the critical mission of improving water quality and protecting the public health. I am extremely pleased to see EPA release such a critical document. This is a tremendous success for the nation's clean water future and shows that progress can be made on tough issues when we work to find collaborative solutions to difficult problems."

The policy was published in the Dec. 22, 2005, Federal Register (http://www.epa.gov/fedrgstr/EPA-WATER/2005/December/Day-22/w7696.htm). To learn more, visit http://www.epa.gov/npdes/wetweather.

This article originally appeared in the 01/01/2006 issue of Environmental Protection.

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