The Clean Air Council is challenging a decision by environmental regulators to allow the Philadelphia Energy Solutions refinery to claim credit for a reduction in emissions caused by the closure of Sunoco's Marcus Hook refinery.

The council on Monday sued to stop the Pennsylvania Department of Environmental Protection from considering the Philadelphia refinery and the closed Marcus Hook refinery as one single air-pollution source. The decision would allow the new owners of the Philadelphia refinery to emit more pollution, at least temporarily.

The arrangement to give the Philadelphia refinery credit for the Marcus Hook emissions was one of the cornerstones of a deal to induce the Carlyle Group to take over operating Sunoco's Philadelphia refinery. The Carlyle-Sunoco joint venture, known as Philadelphia Energy Solutions, became official this month.

Federal and state elected officials, including Gov. Corbett's office and the White House, agreed to instruct state regulators and the U.S. Environmental Protection Agency to amend a consent decree governing emissions at the Sunoco properties.

The decision cuts the Philadelphia plant some slack while the new owners expand and upgrade operations.

But the Clean Air Council says that the change is an illegal attempt to circumvent the Clean Air Act. It filed papers this week asking the state Environmental Hearing Board to revoke the decision.

"Just because you feel you're owed something doesn't mean you can rewrite the law," said Joseph Otis Minott, the council's executive director.

Clean Air Council staff attorney Jay Duffy said DEP's decision to consider the two refineries as a single pollution source contradicts its policy on Marcellus Shale natural-gas facilities, which DEP counts as individual, minor pollution sources rather than as a combined, major source.

He said DEP's Sunoco determination "was an abrupt change to its interpretation of aggregation policy."

Cherice Corley, the spokeswoman for Philadelphia Energy Solutions, noted that the regulatory compromise helped spare the refinery from closure, which Sunoco had vowed if it were unable to find a buyer.

"This has allowed 850 jobs to be saved, 100 to 200 new jobs created, and thousands of construction jobs in the Philadelphia area," she said.

Michael Krancer, DEP secretary, also cited the economic benefits in a blistering response that called the council an "out-of-touch, extreme organization" whose lawsuit would jeopardize thousands of jobs dependent upon refinery operations.

"Ultimately, overall emissions will be lower through, among other things, the use of lower sulfur Bakken Crude oil from North Dakota, which is extracted by horizontal drilling and hydraulic fracturing, and the facility's use of Pennsylvania natural gas for on-site power generation," Krancer said in a statement.