Since acquiring power generation plants across the U.S. in 1999 and 2000, Mirant has spent more than $180 million on projects to reduce power plant emissions — with tremendous results. Our improvements are not over; in Maryland alone, we are in the process of investing more than $1.6 billion in additional air quality control technologies in compliance with the Maryland Healthy Air Act.

A variety of environmental solutions have been implemented across the Mirant fleet. Our options are based on the characteristics of the plant, fuel type and economics; what works for a peaking unit might not be a prudent approach for baseload generation. Some of the strategies to date have included use of low sulfur coals to reduce sulfur dioxide (SO2) emissions and use of equipment such as low-NOx (nitrogen oxide) burners and separated over-fire air (SOFA) technology to lower NOx emissions. These applied technologies have resulted in reductions of these gases.

There are other, larger-scale technologies that yield a very high degree of SO2, NOx and mercury removal, and they are a key part of Mirant’s environmental strategy. These include flue gas desulfurization (FGD) systems — commonly known as “scrubbers” — for SO2 removal, and selective catalytic reduction (SCR) systems for NOx removal. These technologies are highly regarded for providing some of the highest removal rates for these pollutants. In addition to these gases, scrubbers also reduce mercury and particulate (also known as PM2.5 and PM10) emissions.

SCRs are in operation at Mirant plants in the Northeast and West regions, and are currently being installed at our Maryland plants along with scrubbers as part of an extensive program to meet requirements of the Maryland Healthy Air Act. Mirant expects to achieve over 90 percent removal or approximately 29,000 tons of NOx removed from the Mid-Atlantic plants.

At other Mirant facilities, where the scrubber systems do not fit due to technical limitations or physical space constraints, we have taken an innovative approach to environmental solutions. Our Potomac River Generating Station in Alexandria, Va., is one such location that required a unique solution to reduce SO2 emissions. The process Mirant has employed involves a dry powder injection system utilizing trona, the base mineral for baking soda. This has provided substantial reductions in emissions that enable the Potomac River Station to operate within regulatory environmental standards. Specifically, the Potomac River plant has seen up to 80 percent reduction in SO2 emissions since introducing trona. Our specialized process is now being tested at one of Mirant’s plants in New York.