An Idaho Court of Appeals Panel has ruled that Philadelphia-based FMC Corp. must pay the Shoshone-Bannock Tribes $1.5 million annually for waste storage at its closed phosphorus production plant in eastern Idaho.

The panel on Friday affirmed a lower court decision ruling the tribes have jurisdiction over the FMC property and said FMC must comply with tribal environmental laws, The Idaho State Journal ( reported.

The panel upheld a 1998 agreement in which FMC promised to pay the tribes $1.5 million annually to store tons of phosphate ore waste within the reservation. FMC wanted to rescind the agreement after the plant closed in 2002.

"The tribes are pleased the court ordered FMC to honor its commitment to the tribes," said Fort Hall Tribal Council Chairman Nathan Small. "Business conducting activities within the reservation need to understand they are subject to our laws."

The Environmental Protection Agency last month approved a cleanup plan for the Superfund site at the former plant. It calls for capping major areas and putting in extraction and treatment wells downstream.

FMC Corp. is paying for the cleanup. The company operated a phosphorous production plant from 1949 to 2001 on the Eastern Michaud Flats area west of Pocatello, on the Shoshone-Bannock Indian Reservation.

More than a decade after FMC mothballed the operation its capped ponds continue to produce phosphine gas that smells of rotten fish and can damage respiratory, nervous and gastrointestinal systems, and the heart, liver, and kidneys.

The site has been embroiled in legal skirmishes for years. In 2005, the tribes filed a motion in federal court contending FMC was violating tribal law by failing to obtain a waste permit and pay fees. The company contested the fees, but a court ruled the company needed permits.

Those permits required FMC to pay fees that could exceed $100 million annually. The tribes' Land Use Policy Commission revised the system to establish the cost at $1.5 million annually, and FMC filed an appeal over the waste permit, which was rejected.

Information from: Idaho State Journal,