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EPA Issues Administrative Order to Mirant Potomac River - Order Sets Schedule for Mirant to Comply with Clean Air Standards

Release Date: 06/02/2006
Contact Information: Terri White, (215) 814-5523

PHILADELPHIA – The Environmental Protection Agency’s mid-Atlantic region issued an Administrative Order by Consent today to Mirant Potomac River LLC (Mirant) regarding air quality issues at its Potomac River Generating Station in Alexandria, Va.

EPA’s order is designed to ensure the plant complies with national air quality health standards for nitrogen dioxide (NO2), particulate matter (PM10), and sulfur dioxide (SO2).

In December 2005, the Department of Energy issued an order to Mirant requiring operation of the Potomac River plant as necessary to prevent the possibility of blackouts in the central D.C. area.

EPA is requiring Mirant, among other things, to use SO2 emission controls, conduct daily modeling runs based on weather conditions, and install and operate six new SO2 monitoring stations in the vicinity where elevated pollutant concentrations have been predicted. The plant is allowed to operate only where the daily modeling run demonstrates that it will be in compliance with the national ambient air quality standards.

In addition, if at any time the installed SO2 monitors show that the plant is within 80 percent of the federal limits for SO2, Mirant must take measures to reduce its emissions, including the reduction of output, until measured ambient SO2 levels are reduced.

Under DOE’s order, during periods when one or more of the transmission lines that supplies power to the central D.C. area is out of service, the plant is required to operate at higher levels to avert the possibility of blackouts.

Considering the possibility of these line-outage situations, EPA’s order requires that the plant take steps to limit the emission of sulfur from each boiler while meeting the emergency demand. EPA expects the emergency situation identified in DOE’s order should be resolved by June 2007, when PEPCO intends to run additional transmission lines to avoid the need for the Potomac River plant as a backup during power outages.

Last year, air quality modeling revealed concerns about SO2, NO2 and PM10 at Mirant’s Potomac River plant. In response to the urging of the Virginia Department of Environmental Quality, Mirant shut down the plant on August 24, 2005. The plant restarted on a limited basis on September 21, 2005, when subsequent air quality modeling indicated that the limited operation of one boiler – instead of all five boilers – did not cause a modeled violation of any national ambient air quality standard.

The administrative order is effective immediately.