The former owner of the HoltraChem factory in Orrington has petitioned the U.S. Supreme Court to overturn a lower-court ruling requiring the company to pay for a study of mercury contamination in the Penobscot River.

In the latest legal twist of what is already a landmark environmental case, Mallinckrodt Inc. is asking the nation’s highest court for reprieve from an appellate court decision that the company’s lawyers predict could have far-reaching political and economic implications.

“Unless corrected, the 1st Circuit’s decision will fundamentally alter Congress’ allocation of policymaking authority, permitting citizens freely to second-guess [federal] policy and enforcement choices,” Mallinckrodt’s legal team wrote in its appeal to the Supreme Court. “Ultimately, these errors will intrude upon the autonomy of the executive branch and will injure the nation’s economy.”

Mallinckrodt’s opponents in the case – the Maine People’s Alliance and the Natural Resources Defense Council – said they are optimistic that the Supreme Court will decline to hear the case. But they said the ruling of the 1st Circuit Court of Appeals in Boston was on solid legal ground.

“This is precisely the way the law was intended to work,” Nancy Marks, an attorney for New York-based NRDC, said in a statement released Monday.

The two sides have been slugging it out in the courts since 2000 over Mallinckrodt’s liability for mercury found downstream from the now-defunct HoltraChem facility. Mallinckrodt owned and operated the former chlorine and chemical manufacturing facility from 1967 to 1982.

The St. Louis-based company, which is part of Tyco International, is heavily involved in a multiphase cleanup of the factory site. But the company has fought a July 2002 court order that Mallinckrodt pay for a comprehensive study of downstream mercury contamination.

Despite the company’s legal appeals, Mallinckrodt already has allocated more than $2.5 million to the ongoing river study, estimated to cost about $4 million. But crucially, that figure does not include the potentially enormous cleanup costs Mallinckrodt might face for any downstream contamination.

The Court of Appeals upheld the river study in December 2006.

In their court filings, Mallinckrodt attorneys question the legal standing of the Maine People’s Alliance and NRDC when no actual harm from downstream mercury has been proved.

The company’s attorneys also state that the appellate court’s “broad” interpretation of the federal Resource Conservation and Recovery Act “renders meaningless” Congress’ treatment of citizen lawsuits.

Finally, the company argues that the lower court’s ruling wrongly broadens federal judicial power while giving private citizens too much say over policies from the federal Environmental Protection Agency. All of this could stymie industrial development because companies would face increased financial risk.

“Both protection of the environment and the development of industry are public goods,” Mallinckrodt’s appeal states. “The expansive interpretation adopted by the lower courts alters the balance between them, inhibiting production.”

In its response, the legal team for the Maine People’s Alliance and NRDC said that Congress has granted federal courts broad powers to protect public health from toxins and industrial activities. The 1st Circuit was merely joining its sister appellate courts in invoking that authority, the attorneys wrote.

“[The] petitioner tries to paint a dramatic portrait of unconstrained citizens and courts threatening to debilitate the nation’s economy and undermine government agencies,” the attorneys wrote in their response to Mallinckrodt’s appeal.

“In the end, however, this is just a case about a polluter who, for decades, escaped accountability for dangerously contaminating an estuary and who now seeks one final reprieve.”