For John Sirois, chairman of the Confederated Tribes of the Colville Reservation, the issue is simple.
"Where does the pollution end up?" he said. "That's where the jurisdiction would end up."
But Teck spokesman David Godlewski said placing the company, formerly known as Teck Cominco, under the Superfund law is not the right way to proceed. They would prefer a collaborative approach in which U.S. and Canada officials work together toward cleanup, which is estimated to cost up to $1 billion.
Much of the pollution is in the form of a fine black sand that is known as slag. It has washed downstream onto beaches where people camp and swim along the shores of the 150-mile-long lake formed by Grand Coulee Dam. Teck contends the pollution does no harm to humans or wildlife, but a major study of the wastes is ongoing.
Last month, Teck Metals admitted in court for the first time that some of the slag dumped into the Columbia River between 1896 and 1995 flowed into the United States, and some hazardous substances from the slag were released into the U.S. environment.
That admission eliminated the need for a costly trial on the source of the pollution, and allowed the parties to move directly to the issue of who must pay for cleanup.
Teck is one of Canada's largest mining companies, and its smelter 10 miles north of the U.S. border discharged mining waste directly into the river for a century. That waste was carried by swift currents into Washington.
A decade ago, the Colville tribes petitioned the U.S. Environmental Protection Agency to assess contamination in the reservoir. In 2003, the EPA decided Teck was subject to the U.S. Superfund law, and demanded the company pay for studies to determine the extent of the contamination, and then clean it up. Teck objected, and the tribes filed suit in 2004 to force Teck to comply. The state of Washington joined the case.
The next big ruling is expected in December, when U.S. District Judge Lonny Suko is to decide whether the federal court has jurisdiction over Teck, and whether the company's actions made it liable to pay for cleanup.
In its legal brief saying it should be exempt from Superfund, Teck noted it is a Canadian corporation registered in British Columbia that does not do business in Washington. Those are key facts that establish there is no jurisdiction to bring the lawsuit, the company says.
The company also did not "expressly aim" its conduct at the state, and did not know its actions were likely to cause harm, key elements in proving liability, Teck said.
The company contends that evidence it even knew significant amounts of slag settled into Lake Roosevelt is thin. Instead, its experts concluded that any slag carried into the United States eventually would have passed over the Grand Coulee Dam and out of the lake.
"The extent to which slag and effluent settled in Washington state is not known even today," Teck contended.
The slag itself is an inert, granular substance similar to the natural sand sediments, and would have caused little environmental damage, Teck contended.
Even now, the state and National Park Service advertise Lake Roosevelt as an idyllic setting for boating, fishing, swimming, camping and other water-related activities, Teck said.
Teck also contends it is not the sole source of any pollution, as almost 1,000 metals mines and mills have operated in the Columbia River watershed above Grand Coulee since the late 1800s, contributing millions of tons of mineral-rich pollution to the river.
"These metals, as well as metals from landslides and erosion, dwarf Teck's discharges," the company contended.
Since 2006 Teck has been engaged in a major study, under the direction of EPA, of mining pollution in the river. The company has spent more than $55 million on this study. The company contends the study must run its course before any decisions about the pollution can be made.
Godlewski said preliminary findings are encouraging.
"The fish is safe to eat," he said. "The water is safe to play in."
Attempting to hold Teck responsible for the pollution interferes with the sovereign authority of Canada and British Columbia, Teck contends. Canada has repeatedly expressed disapproval over the case, including sending a diplomatic note of protest to the State Department.
The Colville tribes grew concerned about the pollution because their reservation is bordered on the west and south by Lake Roosevelt.
"Teck's actions injured our tribes' lands, waters and other natural resources," Sirois said. "The Columbia River and Lake Roosevelt is a center of our tribal culture."
The tribes and state contend in court documents that as Grand Coulee Dam transforms the free-flowing river into slack Lake Roosevelt, the slag and effluent from Trail sink into the sediments of the lake, rather than flow over the dam.
At least 8.7 million of the estimated 9.97 million tons of slag discharged from the Trail smelter over the decades flowed into Washington, and an unknown portion of its remains in the lake, the state and tribes contend.
"Teck Metals has already acknowledged that it released millions of tons of toxic pollution into Washington state, and we feel confident the federal court will find that U.S. cleanup laws apply to Teck," said Jim Pendowski of the state Department of Ecology.