Perchlorate in LV Wash cut in half by treatment

Thursday, Feb. 3, 2000 | 10:55 a.m.

The amount of the rocket fuel booster perchlorate that has fouled Southern Nevada's waters for decades has dropped dramatically under a cooperative cleanup project by government and corporate efforts, the state was to announce today.

Allen Biaggi, director of the Nevada Division of Environmental Protection, said a temporary diversion system that intercepts and treats a surface stream contaminated with the chemical has reduced the perchlorate flowing into Lake Mead.

The stream, discovered last year at Kerr-McGee Corp. in Henderson, contained as much as 1,000 parts per billion of perchlorate, Biaggi said. That amount has dropped to around 100 parts per billion with the temporary treatment.

Perchlorate, manufactured in Henderson since the 1950s, is a rocket fuel booster that in high concentrations poses a threat to children's growth. In trace amounts it was used 50 years ago to treat thyroid disease.

The amount of perchlorate entering the Las Vegas Wash has dropped in half, Biaggi said. Officials are still trying to identify other sources of the perchlorate.

The wash leads to Lake Mead, Southern Nevada's major drinking water source, and then to the Colorado River, which serves more than 25 million people downstream in Arizona and California.

"This is a real positive step," Biaggi said.

Kerr-McGee, a manufacturer of the chemical that improves rocket fuel performance, is operating a temporary system that diverts the surface stream away from the Las Vegas Wash and cleans it by a chemical process. The clean water is then returned to the wash.

"The good thing about this is it is making a real difference in Lake Mead and the Colorado River," Biaggi said.

There are no federal or state standards for perchlorate concentrations in drinking water, but the state was concerned after finding the contaminated stream last year.

The company is preparing a permanent solution to the perchlorate problem, said David Donnelly, deputy general manager of the Southern Nevada Water Authority.

The company plans to build a pipeline to its plant west of the Boulder Highway and treat contaminated water with a biological process. The advantage to this solution is that as other sources of the chemical are discovered, they can be piped for treatment to a central location, Donnelly said.