BOISE, Idaho— A federal judge on Friday fully vacated a set of approvals by the Bureau of Land Management authorizing development of the Caldwell Canyon phosphate mine in southeastern Idaho.

Phosphate from the mine was slated to be used by Bayer AG — which in 2018 purchased the pesticide giant Monsanto — in manufacturing glyphosate, the active ingredient in Roundup brand products. Glyphosate has been found by the Environmental Protection Agency to pose a risk of adversely affecting 93% of the plant and animal species protected under the Endangered Species Act.

The court said that any economic burdens caused by its decision to vacate the BLM’s prior approvals for development of the mine were outweighed by the need to ensure the ruling did not “incentivize agencies and third parties to ‘invest heavily in potentially illegal projects upfront, only to claim later that the economic consequences in setting aside those projects would be [too great to ignore].’”

“This strip mine would’ve cut through the heart of crucial habitat for greater sage grouse and other species – all in service of producing a pesticide that is itself pushing our most endangered wildlife closer to extinction,” said Hannah Connor, an attorney at the Center for Biological Diversity. “Now sage grouse have a fighting chance at continuing to dance their age-old dances in this place. And the government can’t go on arbitrarily ignoring the environmental harms of phosphate mining.”

Friday’s decision by the U.S. District Court for the District of Idaho vacated the BLM’s approvals for the new open-pit phosphate mine; the phosphate use permit; and rights-of-ways for a road, water pipeline, fiber optic line and powerline. It also vacated the agency’s environmental review under the National Environmental Policy Act.

The decision follows the court’s ruling in January that the BLM had violated the National Environmental Policy Act and Federal Land Policy Management Act when it approved the phosphate mine without first analyzing and restricting, mitigating or eliminating impacts to greater sage grouse, such as harms to habitat and population connectivity.

“We are relieved that the Caldwell Canyon mine will not proceed until its environmental and public health impacts are properly studied,” said Sarah Stellberg, a staff attorney with Advocates for the West. “Southeast Idaho deserves better than another ill-conceived phosphate project.”

These decisions build on prior legal victories for protection of greater sage grouse against mineral development.

“This is an important ruling, not just because it underscores the legally binding nature of habitat protections in the federal sage grouse plans, but also because it means that federal grouse protections must apply regardless of state agency policies,” said Erik Molvar, a wildlife biologist and executive director of Western Watersheds Project. “By ruling that the Bureau of Land Management failed its obligation to assess the cumulative impacts of regional developments on the viability of the faltering East Idaho Uplands sage grouse population, this victory creates a legal precedent that federal bureaucrats can’t keep subjecting sage grouse populations to a death by a million cuts.”

The court’s January ruling also determined that the BLM violated the National Environmental Policy Act when it failed to consider effects on public health and the environment from sending the phosphate rock to be processed at the Soda Springs Plant. That plant, also owned by Bayer AG, was listed as a Superfund site in 1990 for, among other things, selenium and cadmium contamination to the region’s groundwater.

“Everyone, but especially the people living near the Soda Springs Plant, has an interest in knowing the public health effects of potentially extending the operational life of a Superfund site for 40 additional years,” said Chris Krupp with WildEarth Guardians. “As the law requires, the Bureau will now be providing this important information.”

According to sworn testimony from P4 — a subsidiary of Bayer AG and intervenor in this matter — phosphate extracted from the Caldwell Canyon mine is a vital component for producing and distributing glyphosate globally. Glyphosate is the most widely used pesticide in the world and has been linked to cancer in humans, as well as to harm to more than 1,600 of the plant and animal species protected under the Endangered Species Act.

The court’s ruling is in response to a 2021 challenge to a decision by the BLM to approve approximately 1,559 acres of ecologically important land essential to the imperiled greater sage grouse and other species to be strip-mined for phosphate.

That lawsuit was filed by the Center for Biological Diversity, Western Watersheds Project and WildEarth Guardians. The conservation groups are represented by Advocates for the West, the public-interest law firm Smith & Lowney, and in-house counsel with the Center for Biological Diversity.