After a year of litigation, the Homer City Generating Station, the largest source of sulfur dioxide (SO2) pollution in the entire country in 2010, will now be subject to a precedent setting hourly limit for SO2 pollution. The new protections aim to ensure that the coal-fired power plant never exceeds Environmental Protection Agency (EPA) health standards for sulfur dioxide, even during startup and shutdown, protecting the health of families across the region.

The Homer City Generating Station looms over US 119 in Pennsylvania.  (Jon Dawson)

The new protections set a national precedent in the fight to secure the health and safety of families in coal-dependent Pennsylvania and beyond. These new conditions to the Homer City permit are among the first in the nation to set hourly limits on SO2 emissions. Sulfur dioxide is one of the most dangerous pollutants to come from coal-fired power plants. Just five minutes of exposure can lead to respiratory problems, difficulty breathing, contribute to lung disease and cause heart attacks. In 2010, EPA issued a new 1-hour SO2 health standard based on scientific evidence that linked short-term exposure to sulfur dioxide with these adverse health effects. EPA expected the new standard to benefit millions of Americans, in particular, children, the elderly, and asthmatics.

“The Department of Environmental Protection has done the right thing by setting an hourly sulfur dioxide limit at Homer City,” said Charles McPhedran, an attorney with Earthjustice. “With this new limit, we know that the scrubber project at the plant will provide health benefits as measured by the EPA yardstick.”

The Homer City power plant has two coal-fired units that, until recently, have had no controls for limiting the emission of SO2. In 2010, these units emitted more than 109,000 tons of SO2, making Homer City the largest source of SO2 emissions in the country that year. The Pennsylvania Department of Environmental Protection (DEP) has determined that Indiana County is violating the SO2 health standard, and EPA recently recommended that the county be designated as failing to attain this standard.

"The new clean air protections at Homer City provide critical protections against sulfur dioxide and will ensure that families living near this plant can breathe easier," said Mary Ann Hitt, Director of the Sierra Club’s Beyond Coal Campaign. "Today’s victory and sets an important standard for other clean air fights across the country. As we continue the fight to replace old dirty energy sources with clean renewable ones like wind and solar, we must make sure to limit the dangerous pollution from our remaining coal-fired power plants."

In 2012, Earthjustice, on behalf of the Sierra Club, appealed an air quality permit for the plant. In settlement, the plant accelerated air quality modeling to determine the impacts of SO2 and DEP agreed to a timeline for a permit revision to ensure compliance with the SO2 health standard.

On April 4, 2013, after review of company modeling data, DEP added new permit conditions limiting combined SO2 emissions from the three plant generating units to 6,630 pounds per hour, including during periods of startup and shutdown, and prohibiting more than one unit from operating simultaneously in high-polluting startup mode. Because this emission rate contained a typographical error, Sierra Club filed a new appeal. In response, DEP has now modified the permit to limit emissions of sulfur dioxide to 6,360 pounds per hour.