Exxon Mobil Corp. violated a state water-use permit while constructing an ice road across the North Slope, state officials said Tuesday.
The company is building the 50-mile ice road to support development of its remote Point Thomson oil and gas field.
Such roads are made by laying down a strip of ice, typically at least 6 inches thick, using ice chips and water drawn from lakes, rivers and flooded gravel mines on the Slope.
Ice roads, which typically melt away in summer, provide a safe way to haul heavy equipment such as drilling rigs across the delicate tundra.
An Exxon contractor, Alaska Frontier Constructors Inc., last week pumped water from the broad Sagavanirktok River delta as part of work to build the road east to Point Thomson.
But a work crew failed to first test the water to make sure it was brackish and not fresh water, said Gary Prokosch of the state Department of Natural Resources.
Taking fresh water from the river isn't allowed because it's important for winter survival of whitefish and other species, said Bill Morris, a habitat biologist with the state Department of Fish and Game.
About 28,350 gallons of river water were used before Exxon and the contractor realized water from the site wasn't suitable, Prokosch said.
The 28,350 gallons is "a small amount of water relative to what's out there," and no contamination or other environmental harm was done, Prokosch said.
Exxon might get a violation notice and a fine is possible but not likely, he said. State officials will work with Exxon and its contractors on the water-use rules.
"It's a very benign type of situation," Prokosch said. "Our real goal is to make sure it doesn't happen again."
An Alaska Frontier manager referred questions to Exxon.
Exxon itself reported the improper water pumping and the "situation has been corrected," the company said in a statement Tuesday.
A state incident report says Exxon learned of the improper pumping and contacted Alaska Frontier, which "immediately shut down water usage from the area in question" and moved its pumping operation to another site.
State officials late last month gave Exxon permission to build the ice road and drill at Point Thomson after the two sides reached a partial settlement on the fate of the rich but long-dormant field.
The state had been pursuing efforts to reclaim the acreage and lease it to new companies on grounds Exxon couldn't be trusted to carry out its promised drilling.
The ice road construction project recently hit another glitch -- a sleeping polar bear.
To avoid disturbing the bear, Exxon decided to change its road route to stay at least a mile away, said Craig Perham, a biologist with the U.S. Fish and Wildlife Service.
Find Wesley Loy online at adn.com/contact/wloy or call 257-4590.