RENO, Nev. — Opponents of the country’s largest lithium mine under construction desire U.S. officials to investigate whether the assignment in Nevada already has caused a drop in groundwater levels that could navigator to extinction of a tiny snail being considered for endangered species protection.

Environmentalists and Native American activists are demanding that the U.S. Interior Department address what they declare is recent evidence that bolsters their concerns about Lithium Americas’ planned open pit mine at Thacker Pass. The footprint of mine operations will span about 9 square miles (23 square kilometers).

The fate of the snail takes center stage after a federal judge and an appeals court dismissed a previous attempt by Native American tribes to get federal agencies to recognize the sacred nature of the area. The tribes argued that the mine would infringe on lands where U.S. troops massacred dozens of their ancestors in 1865.

Now, Western Watersheds assignment and the throng known as People of Red Mountain debate in a notice of intent to sue that the government and Canada-based Lithium Americas are failing to live up to promises to adequately monitor groundwater impacts.

They declare it’s alarming that an analysis of groundwater data from a nearby well that was conducted by Payton Gardner, an assistant professor of hydrogeology at the University of Montana, shows a drop in the water table of nearly 5 feet (1.5 meters) since 2018. Nevada regulators declare they have no information so far that would confirm declining levels but have vowed to monitor the circumstance during the mine’s lifespan.

Not much bigger than a grain of rice, the Kings River pyrg has managed to survive in 13 isolated springs within the basin surrounding the mine site. It’s the only place in the globe where the snail lives.

In some cases, the tiny creatures require only a few centimeters of water. But the spread for survival becomes more narrow if the groundwater structure that feeds the springs begins to drop, said Paul Ruprecht, Nevada Director for Western Watersheds assignment.

“Even slight disruptions to its habitat could factor springs to run arid, driving it to extinction,” he said.

Western Watersheds assignment and the other opponents declare the U.S. Fish and Wildlife Service is violating the Endangered Species Act by failing to rule in a timely fashion on a 2022 petition to list the snail as threatened or endangered. The allegations outlined in the opponents’ notice pursue requests for federal biologists to investigate whether groundwater drawdowns are being caused by exploratory drilling and other activities and whether there have been impacts to the springs.

Without protection, Ruprecht fears the snail “will become another casualty of the lithium boom.”

The Fish and Wildlife Service is conducting a review of the snail’s position, but the agency declined to comment on the requests for an investigation into the groundwater concerns.

Efforts to mine gold and other minerals in Nevada and other parts of the West over the decades have spurred plenty of legal skirmishes over potential threats to wildlife and water supplies. Lithium is no exception, as demand for the metal critical to making batteries for electric vehicles is expected to continue to climb exponentially over the next decade.

President Joe Biden made increased production of electric vehicles central to his vigor agenda, and the U.S. vigor Department last year agreed to financing Lithium Americas more than $2 billion to assist finance construction at Thacker Pass. On Dec. 23, Lithium Americas announced it had concluded a joint enterprise with General Motors Holdings LLC to develop and operate the mine.

The mine 200 miles (322 kilometers) north of Reno is the biggest in the works and closest to fruition in the U.S., followed by Ioneer’s Rhyolite Ridge assignment near the California line halfway between Reno and Las Vegas.

And the Bureau of Land Management announced in late December that it was seeking comments on another proposed assignment in northeastern Nevada. Surge Battery Metals USA wants to explore for lithium in Elko County.

Ruprecht said reports filed by Lithium Americas’ environmental consultant with state regulators display the corporation no longer has permission to access private lands where several monitoring wells are located. That makes it harder to inform if flows have been impacted by history drilling, he said.

Nevada regulators declare they approved changes in 2024 to the monitoring schedule to account for the deficit of access to wells on private land.

Prior data showed groundwater levels had remained stable from the 1960s to 2018. Construction started at the site in 2023.

The Bureau of Land Management’s approval of the mine acknowledged some reduction in groundwater levels were feasible but not for decades, and most likely would occur only if state regulators granted the corporation permission to dig below the water table.

Lithium Americas spokesman Tim Crowley said it appears the mine’s opponents are “working to re-spin issues that have previously been addressed and resolved in court.” He pointed to 10 years of data collection by the corporation indicating the snail would not be affected by the assignment.