Impact of the Healthy Air Act


New data from the Maryland Department of the Environment show a remarkable drop in sulfur dioxide and nitrogen oxide emissions from Maryland’s power plants, thanks to the state’s Healthy Air Act that passed in 2006.

The Healthy Air Act limits nitrogen oxide, sulfur dioxide and mercury pollution from electricity generators in Maryland. It also requires those facilities to participate in the Northeast’s Regional Greenhouse Gas Initiative (RGGI), which is a cap-and-trade system to reduce global warming pollution from power plants.

Frontier Group wrote Power Plants and Global Warming, released in 2005, explaining the feasibility of reducing the global warming emissions from power plants in Maryland. That report also explored how improving energy efficiency would both cut carbon dioxide emissions and improve air quality and public health.

The nitrogen oxide standards of the Healthy Air Act took effect on January 1, 2009, and the sulfur dioxide requirements took effect on January 1, 2010. To comply with the law, power generators have installed a variety of control equipment, items with names such as flue gas desulfurizers, baghouses, hydrated limestone injection systems, and powdered activation carbon injection systems. While I can’t claim to understand how these work, I do know that the data in the two charts below show remarkable declines in emissions and a victory for public health in Maryland.