Severe environmental impacts would result from any large-scale development of oil shale resources, including those in Utah, conservationists say.

Leading the charge against the alternative fuel source are the Western Colorado Congress, Western Resource Advocates, Natural Resources Defense Council and Wilderness Workshop.

In a recent statement, they point out that Rep. Mark Udall, D-Colo., wants to pass legislation prohibiting the Bureau of Land Management from completing its commercial oil shale leasing program or issuing commercial leases "until the BLM's oil shale research and development process determines the feasibility and likely impacts of a commercial industry."

"The Bureau of Land Management is pressing for commercial oil shale leasing," said Cathy Kay of Western Colorado Congress, interviewed by telephone. The group is a nonprofit organization based in Grand Junction, Colo., with eight chapters across Colorado's Western Slope, she said.

Utah also has huge oil shale resources, and she said one company has been awarded a permit to explore for oil shale in the Beehive State.

The groups contend that developing oil shale on Colorado's West Slope will require 12,000 megawatts of electricity, probably from coal-fired power plants.

In a press release, they quoted Dr. Brian Moench, president of Utah Physicians for a Healthy Environment, about oil shale development concerns.

Contacted by the Deseret Morning News, Moench said he believes large-scale development would cause dangerous air pollution.

"The amount of electricity required for that (oil shale) process is just enormous," he said. It would make it "staggeringly unfeasible" to produce the oil.

Oil shale production technology is so speculative that it seems almost like science fiction, Moench added.

"The electricity demands are incredible; the water consumption is also incredible."

It's not as if oil shale is energy-intense, he said. Oil shale is rock with hydrocarbons in it. The hydrocarbons must be released from the rock, which is not like pumping oil from the ground.

"The energy density of oil shale is comparable to a potato. Manure has four times as much energy density as oil shale does," Moench said.

He added that coal produces something like 10 times as much energy per mass as oil shale. Oil shale is "just not a decent energy source," he added.