The Environmental Protection Agency’s actions to develop a plan to control sulfur dioxide pollution in the Yellowstone Valley were reasonable, an appellate court has ruled.
An order issued last week by the 9th U.S. Circuit Court of Appeals denied a review sought by the Montana Sulphur & Chemical Co., saying the EPA “did not act arbitrarily or capriciously” with Montana’s state plan, or a later federal plan, to regulate the pollutant.
MSCC, a sulfur plant that processes waste gases from the ExxonMobil refinery, challenged EPA’s 2008 federal plan and the agency’s 1993 notice that Montana’s plan was “substantially inadequate” to protect public health and meet federal air quality standards and had to be revised.
A MSCC representative could not be reached for comment.
The state’s plan, called a State Implementation Plan, regulates how the valley’s seven industrial sources of sulfur dioxide, including MSCC, will comply with federal air quality standards. EPA said the state’s plan was inadequate after computer modeling in the 1990s showed pollution levels exceeding national standards.
The Montana Department of Environmental Quality, working with EPA and the industries, revised its state plan to show compliance. But EPA rejected portions of the state plan in 2002 and 2003 and developed its own plan to fill the gaps.
The nearly 20-year dispute between MSCC and EPA focused on controlling sulfur dioxide pollution, which is a respiratory irritant and contributes to acid rain.
MSCC was the only industry to challenge EPA’s initial finding that the Montana plan was inadequate or its actions on the state or federal plan. Montana DEQ also did not challenge EPA’s actions.
One of the main disputes between MSCC and EPA was the company’s 100-meter smokestack. The company built the stack after EPA’s 1993 notice. The state’s revised plan allowed MSCC to have a variable emission rate based on a stack height of 97.5 meters.
EPA rejected the state’s approach as improper and set a fixed emission rate based on a stack height of 65 meters. The agency said federal regulations do not allow building taller smokestacks to send pollution higher into the air rather than controlling it at the source.
MSCC also disputed EPA’s limits on flare emissions, which can be a significant source of sulfur dioxide. The EPA plan restricted the amount of pollution that could be flared during a three-hour period and also required the industries to install monitors on the gas stream that goes to the flare.