SIERRA VISTA - The man who wants to buy an abandoned rail line running from Paul Spur to Benson said he is watching events unfold in the wake of an environmental group's lawsuit.

On Wednesday, the Phoenix-based Center for Biological Diversity filed a complaint in U.S. District Court against the United States Surface Transportation Board for failing to consider impacts of a rail line on the San Pedro Riparian National Conservation Area.

Charles Sotelo, manager of the Sonora-Arizona International Corp., which wants to buy the abandoned rail line, said he is aware of the lawsuit.

"We understand the issue on both sides, and we understand there will be closure," Sotelo said. "The STB will make a decision one way or the other, and the Center for Biological Diversity will be happy or sad.

"I'm just like everybody else," he said. "I'm going to sit back and watch."

Sotelo said the center's lawsuit did not surprise him. "The center has a history, and we know it," he said.

Sotelo has said he has an investment group that has made an offer to buy the inactive rail line, as one way of creating jobs.

In an April 17 article published in the Herald/Review, one of the project's investors, Lou Kuttner, said it could be three years before the rail line is operating.

The STB - an economic regulatory agency with duties including the review of proposed railroad mergers - approved the rail line's sale on May 3.

"We would like to stop the project altogether," said Michelle T. Harrington, Rivers Program director with the center on Thursday.

One of the center's concerns is that such a rail could bring hazardous chemicals dangerously close to the San Pedro, the last free-flowing river in the Southwest, and possibly damage the riparian corridor.

According to a spokesman with the STB who declined to identify himself, the Washington, D.C.-based agency had not seen the lawsuit as of Thursday afternoon.

Supervisor Paul Newman, whose district includes Naco, Ariz., said there is a huge issue with water quality at the San Pedro River.

"I don't believe the STB has ever thoroughly dealt with that," Newman said. "I concur that if they plan on building a rail line, there needs to be a full-blown environmental review to measure the potential negative environmental impacts on river. That's no small matter, and will cost a pretty penny."