Corps focuses on eradicating Cheyenne water contaminant

CHEYENNE -- The U.S. Army Corps of Engineers' move to further reduce the level of a chemical in Cheyenne's water supply is the most crucial part of the cleanup of contamination from an old nuclear missile site, a state scientist said Friday.

U.S. Sen. John Barrasso, R-Wyo., announced late last week that the corps has agreed to use an advanced aeration system to decrease trichloroethylene in the capital city's water supply to an undetectable level.

Barrasso, who has been working on the Cheyenne water contamination problem since 2008, commended the corps' action.

"I am pleased with the Army Corps of Engineers' recent decision to use a state-of-the-art treatment system to reduce the level of TCE in the water supply to an undetectable level. It's good to see that it will be resolved without Wyoming taxpayers having to foot the bill," Barrasso said.

The city has been treating the groundwater, but has been unable to reduce the TCE to undetectable levels.

On April 5, Bud Spillman, the manager of the city's water treatment division, sent Barrasso the blueprint for an advanced aeration system that would allow for the complete removal of TCE from Cheyenne’s groundwater supply.

Barrasso followed up on April 14 with a letter to the Corps of Engineers demanding that it utilize the advanced aeration system

Jane Francis, geological supervisor with the Wyoming Department of Environmental Quality, said Friday that the new aeration system is key to cleaning up the TCE.

The more "intractable problem" is cleanup of the source area -- a 10- to 14-mile-long plume of TCE from the old Atlas missile site west of Cheyenne, she said.

Francis said representatives of the corps met with state scientists May 11 and 12 and agreed to drill more wells and perform more pump tests.

"That will help with the cleanup. But there's no guarantee we can clean that up," Francis said, citing the size of the plume.

"The city may be treating for a long time," she added.

Spillman said Friday that the corps shifted gears to deal with the water treatment problem separately from the overall contamination.

The corps initially said it was required to reduce the TCE level to 5 parts per billion.

"We told them that was not acceptable," Spillman said. "We said we expected treatment would result in complete removal."

Spillman said the city contacted Barrasso for his help in getting more robust treatment of the water supply.

"We're very appreciative of Senator Barrasso's efforts. We couldn't have done that without him and his staff," Spillman said.

In the early 1990s, the Wyoming Department of Environmental Quality and the city of Cheyenne found evidence of TCE in the city's water wells. TCE is an industrial solvent used in cleaning rocket motors.

It wasn't until 2008 that the Corps of Engineers released a report that confirmed the there was a link between the old Atlas missile site and the city's wells.