Las Vegas Sun

March 29, 2024

Officials say effort to lower perchlorate levels is working

The level of perchlorate in the source of Southern Nevada's drinking water has been on the decline since the Nevada Division of Environmental Protection began cleanup efforts in November 1999, water officials say.

Current levels of perchlorate in Lake Mead, which provides 90 percent of the Las Vegas Valley's drinking water, are just above 7 parts per billion, Southern Nevada Water Authority spokesman J.C. Davis said Tuesday morning at a Lake Mead Water Quality Forum meeting. That's down from an average of 9.8 parts per billion in 2003.

"There's no question that it's improving," Davis said. The state agency "is doing a great clean-up job with Kerr-McGee," he said.

Kerr-McGee is one of two Henderson factories from which perchlorate, a booster for rocket fuel, leaked into the surrounding ground water for 30 years. It traveled Henderson through the Las Vegas Wash into Lake Mead.

Kerr McGee stopped making perchlorate in 1998. American Pacific, the other company that produced it, moved to St. George, Utah, after an explosion in 1989 destroyed its Henderson plant.

Perchlorate can slow human thyroid activity.

Kerr-McGee and American Pacific, which have their own monitoring wells, have been working to pull perchlorate out of the water, Todd Croft, who oversees the remediation efforts for the state environmental agency, said.

The current plants have pulled 1,144 tons of perchlorate out of the water since they came online, or about 2,000 pounds a day, Croft said.

The ongoing drought, however, has undermined some of the efforts to lower the level of perchlorate in the water, Davis said.

"We would be seeing a much larger reduction if we had more water coming down the (Colorado) river," Davis said. "Dilution plays a huge role in the cleanup effort."

The state does not have any set recommendations for allowable perchlorate levels in the drinking water, and local officials said they are following the national debate on the subject. But water quality remains a primary concern for local agencies.

Officials with the Southern Nevada Water Authority and the Clean Water Coalition are looking at possible options to draw water from deeper locations in the lake where the water quality is better, officials told the forum Tuesday.

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