WASHINGTON— Nearly 100 national and regional organizations have urged Congress to reject a provision in the annual defense spending bill that would cede historic lands of the Shoshone-Bannock Tribes in Idaho to expand a radioactive waste dump at one of the country’s largest Superfund sites.

The groups are calling on congressional leaders to oppose the provision authored by Sen. James Risch (R-Idaho) and cleared for inclusion into the Senate’s National Defense Authorization Act by Sen. Martin Heinrich (D-N.M.).

“This toxic waste dump expansion at the edge of the Portneuf River will harm salmon downstream through the Snake and Columbia rivers and spit on Native American treaty rights. It’s absolutely abhorrent,” said J.W. Glass, senior EPA policy specialist at the Center for Biological Diversity. “It’s dumbfounding that some senators are hellbent on rewarding a mining company, especially when an alternative waste site could’ve been found at any time over the past 30 years.”

In 1898 the Shoshone-Bannock Tribes ceded vast areas of their ancestral homelands to the United States under an agreement that reserved crucial Tribal rights, including fishing access to those lands. Since 1994 mining company J.R. Simplot has attempted to acquire 700 acres of Tribally ceded public lands along the Portneuf River to expand a mining waste dump.

In 2020 the Bureau of Land Management approved handing over those lands to the mining company in exchange for a roughly equivalent amount of land elsewhere. The land exchange was deemed unlawful by the U.S. District Court of Idaho in 2023 and by a federal appeals court in 2024. It was rejected by a full federal appeals court panel in 2025. Each court ruled that the land exchange violated the treaty rights of the Shoshone-Bannock Tribes.

The Senate’s National Defense Authorization Act would authorize exchanging 700 acres of historic, culturally significant Tribal lands for other land. If the provision is included in the final legislation, the Tribal lands would be used to expand a phosphogypsum mining waste site and likely further contaminate the Portneuf River.

In April the Center for Biological Diversity, along with Waterkeeper Alliance, Bayou City Waterkeeper, Sierra Club, Manasota-88, Wildearth Guardians, Snake River Waterkeeper, Western Watersheds Project, Portneuf Resource Council and others, filed a friend of the court brief in support of the Shoshone-Bannock Tribes at both the district court and appellate court levels.

“We’re appalled at our federal lawmakers’ blatant disregard for the Shoshone-Bannock Tribes' treaty rights” said Buck Ryan, executive director of Snake River Waterkeeper. “The court firmly upheld the Tribes’ rights by rejecting this unlawful land exchange, and this is a shameful attempt to circumvent the justice system and the appropriate outcome in this matter.”

Phosphogypsum is a radioactive, carcinogenic waste associated with phosphoric acid production used to manufacture fertilizer.

The existing waste stack currently covers 500 acres, stands as high as 240 feet, and contains millions of tons of phosphogypsum waste. It is part of the designated Eastern Michaud Flats Superfund site because of elevated levels of arsenic, cadmium and selenium that have contaminated the surrounding groundwater.

“Fertilizer production is a cradle-to-grave operation of pollution,” said Glenn Compton, chairman of Manasota-88. “The cradle is the mining of the phosphate ore that strips away all vegetation from the land at the beginning of the process, and the grave is the radioactive and toxic waste dumping of the phosphophogypsum. The phosphate industry should not be permitted to externalize the costs of their phosphogypsum waste disposal problem at the public’s expense. The cost is too high.”

Because expanding this waste dump is unrelated to any defense or national security issue, both Sen. Mike Lee (R-Utah), chair of the Senate Environmental and Natural Resources Committee, and Heinrich, a ranking member, needed to approve including the legislative provision in the Senate bill. A similar provision was proposed as an amendment in the House but was not included in the House version.