Two conservation groups representing Montana landowners are challenging the Bureau of Land Management and Interior Department in federal court for selling oil and gas leases on 150,000 acres of public land in the state.

The suit, filed Tuesday in Great Falls District Court by Earthjustice and the Montana Environmental Information Center on behalf several landowners, accuses the two agencies of “turning a blind eye” to the groundwater contamination and climate pollution that will result from the lease sales.

“BLM is well aware that current oil and gas drilling practices do not adequately protect underground sources of water,” said Earthjustice attorney Elizabeth Forsyth. “BLM cannot continue to usher in oil and gas development to rural Montana while turning a blind eye to groundwater contamination.”

Under Interior Secretary Ryan Zinke, the BLM proposed leasing more than 98,000 acres of public land in December and another 46,000 acres in March.

Those behind the suit believe oil and gas development across so many acres of public land places ground and surface water at risk, harms public resources and jeopardizes the health and livelihoods of area ranchers.

“I’m concerned that nearby oil and gas development could jeopardize usable groundwater, and threaten the Stillwater River, which is already stressed by drought and increasing temperatures,” said David Katz, a longtime Stillwater County landowner. “The production from these leases will be small, but the long-term impacts on our community will be great.”

According to the suit, hydraulic fracking in Montana is currently concentrated in the Bakken shale formation near the North Dakota border. The recent BLM lease sales “pave the way” for the fracking boom to move south and west into Montana, threatening an area “the size of the city of Chicago.”

The suit contends that BLM failed to address the impacts of oil and gas drilling on groundwater aquifers, and failed to evaluate the impacts on climate change.

“BLM did not adequately evaluate the effect of the challenged lease sales on greenhouse gas emissions and resulting climate change impacts, perpetuating the fundamental disconnect between the federal government’s management of public lands and the changing climate,” the suit states.

The suit is asking the court to void the leases and find that BLM and Interior violated the National Environmental Policy Act in approving the lease sales.

“We are very concerned about the contamination of our wells,” said Bonnie Martinell, who owns and operates a chemical-free produce and hay farm north of the Elk Basin oil field. “With the increased drought conditions and a semi-arid environment, we may need to drill deeper for water that may be contaminated by these oil wells.”