Officials said the completion of the Flight 93 Memorial may be delayed after a toxic substance was detected in the ground.

State environmental officials said manganese, a by-product of a coal mine, was found at the site.

Officials said the coal company is trying to clean up the manganese, but are having trouble because they can't -- and won't -- dig up the earth where the victims' remains lie.

However, the land must still be cleaned and treated, a process some fear might take several years.

"I'm concerned that we're not going to build the memorial under the time schedule we put forward, and that's the 10-year anniversary in 2011," said Rep. Bill Shuster, R-Somerset.

A state official said there is no consensus on how to complete the treatment or how to pay for it all. Further, the National Park Service, which will operate the monument, refuses to take over the project until all cleanup is complete.

"Because of the bureaucratic red tape here, that's going to be an affront -- an insult -- to the people of Shanksville and to the families of the flight and crew of Flight 93," Shuster said.

Shuster said he will ask the federal Environmental Protection Agency to waive its rules and allow the park service to complete the project despite the manganese pollution.

He said the levels of the toxin might violate federal standards, but said they aren't dangerous or a threat to visitors' safety.

Jessica L. Emond, Deputy Press Secretary, U.S. Environmental Protection Agency, said, "EPA headquarters and regional staff have been working diligently with local officials to review this issue. Administrator Johnson plans to respond to Congressman Shuster early next week."

Residents visiting the Memorial today said they are sad to hear the news, that construction has already taken too long to begin.

"Something needs to be done and it needs to be done right now," a visitor said.

Officials with the Park Service in Somerset County were unavailable for comment on the toxin situation on Friday.