Permit Approved for Mirant Power Plant


The State Air Pollution Control Board has unanimously approved the two-stack permit for the Potomac River Generating Station operations proposed by the Virginia Department of Environmental Quality and agreed upon by Mirant and the City of Alexandria. The Alexandria City Council previously approved the agreement. The settlement document and additional information are available at

This permit incorporates many of the key terms of the settlement agreement between Mirant and the city and makes them enforceable at state and federal levels.

The permit:

  • Requires the investment of $34 million by Mirant on new pollution control technology for particulate emissions.
  • Gives the city control over selection and implementation of these new technology controls.
  • Imposes an emission limit on particulate matter less than 2.5 microns in size (PM2.5). The limit complies with the National Ambient Air Quality Standards.
  • Requires Mirant to drop its legal challenge to the sulfur dioxide emissions limit of 3,813 tons per year.
  • Requires installation of carbon monoxide and particulate matter continuous emissions monitors, thereby allowing enforcement of applicable limits.
  • Gives the city access to emissions monitoring data and access to the plant during the design and installation of the new controls.
  • Requires immediate installation of additional fugitive dust controls.
  • Requires installation and operation of an additional PM2.5 monitor.