The U.S. EPA is requiring a natural gas processing facility to capture and permanently store carbon dioxide (CO2) and hydrogen sulfide underground. The EPA reached an agreement with Merit Energy Company, LLC and Shell Exploration & Production Co. on alleged Clean Air Act violations at Merit’s facility at Manistee, Michigan. Although other natural gas processing plants have used acid gas injection for carbon capture and storage (CCS), this is the first Clean Air Act enforcement case that requires it, according to the media.

Merit, the current owner of the natural gas processing facility, will store these gases by injecting acid gas—a mixture of carbon dioxide and hydrogen sulfide—into depleted natural gas fields. By storing these gases underground, Merit will reduce its carbon dioxide emissions by roughly 3,800 tons annually and its sulfur dioxide emissions by 170 tons annually in this 100 percent emissions control system. Merit must install and operate the acid gas injection system—at an estimated cost of over $1 million—by September 1, 2009. If Merit fails to complete the acid gas injection system or shut down its facility, it faces penalties of up to $20,000 per day. Merit must obtain permits for the acid gas injection system from the EPA, state, and local regulators. Additionally, Merit must submit a monitoring plan to the EPA for approval at least 90 days prior to Merit operating the acid gas injection system, as well as quarterly progress reports.

Merit must also implement a Supplement Environmental Project (SEP) that consists of replacing natural gas fired internal combustion engines with electric compressor drives within 17 months of the consent decree. This SEP project—at an estimated cost of $1 million—will eliminate air pollutant emissions from three units near its facility. If Merit fails to implement the SEP, it must pay a penalty of $1.2 million. The consent decree also requires Merit and Shell, the former owner of the facility, to jointly pay a fine totaling $500,000.

Although the media has portrayed this as the first CCS-related consent decree in the United States, we aren't so sure. It looks like acid gas injection to us, and folks have been doing that for decades.