An industrial gas producer has agreed to pay $1 million to settle air-emissions violations at its northwestern Montgomery County plant, the Pennsylvania Department of Environmental Protection announced Wednesday.
Matheson Tri-Gas Inc. agreed to settle charges that it operated its plant on Stauffer Road in Upper Hanover Township without proper permits for five years after buying the facility from Advanced Gas Technologies.
The rural plant produces high-purity specialty cylinder gases, primarily propylene.
DEP said Matheson reported in 2012 that its emissions of volatile organic compounds were "higher than previously known," according to a consent assessment of civil penalty it signed earlier this month.
Matheson and the previous owner had failed to account for gases that were purged from cylinders before they were refilled, said Virginia Cain, a DEP spokeswoman.
"When Matheson realized this oversight, they approached the department with the estimates based upon the amount of cylinders filled and what they estimated is lost during each purge," Cain said in an email.
The company estimated that 34 to 49 tons of volatile organic compounds were emitted annually between 2010 and 2012.
The purged gases included propylene, propane, n-butane, isobutene, isobutylene, 1-butene, n-pentane, ethane, ethylene, isopentane, methane, and carbon monoxide, Cain said.
Matheson "worked promptly to resolve all violations and attain the necessary permits and approvals," DEP said.
The company installed a thermal oxidizer at the plant in 2013 to control emissions at a cost in excess of $1 million, said John Molnar, a Matheson spokesman.
Matheson, which is based in Basking Ridge, N.J., is owned by Taiyo Nippon Sanso Corp. of Japan.
"We worked long and hard with DEP to not only have a resolution, but to get into good standing with DEP," Molnar said.
The $1 million settlement will be paid to the Pennsylvania Clean Air Fund.