Contaminated water found flowing into Las Vegas Wash

Friday, July 9, 1999 | 11:40 a.m.

State environmental officials have discovered a new source of perchlorate flowing into Southern Nevada's major drinking water supply.

Water coming from old industrial ponds north of Pabco Road in Henderson has 100 parts per million of perchlorate in it. The contaminated water is flowing through a newly discovered channel into the Las Vegas Wash.

Perchlorate, manufactured in Henderson, is a rocket fuel booster that in high concentrations poses a threat to children's growth.

There are no federal or state standards for perchlorate concentrations in drinking water, but 100 parts per million is considered worthy of concern, officials say.

The Nevada Division of Environmental Protection and Kerr-McGee Corp., the manufacturer of the rocket fuel oxidizer ammonium perchlorate, are working to stop the flow of contaminated water into the wash, which is six miles upstream from Lake Mead, the Las Vegas Valley's major drinking water supply.

The amount of perchlorate in the newly discovered stream is more than 100 times higher than amounts found in the wash above the stream.

Allen Biaggi, state environmental protection director, said that removing the contaminated water from the wash within two to four months offers a rare opportunity to improve Southern Nevada's water quality.

"While it is a startling discovery, it provides an opportunity to improve water quality in a short period of time," Biaggi said Thursday at the Lake Mead Water Quality Forum.

Perchlorate is a salt that enhances rocket fuel performance. It also is used as a treatment for people with overactive thyroids.

Medical records from the 1950s indicated that concentrated doses caused growth problems in children and blood disorders.

Perchlorate has been found in Las Vegas' drinking water but the concentration levels are so low that they do not pose a health threat to local children or those with thyroid problems, Biaggi said.

Biaggi estimated that half of the perchlorate running into the wash each day will be eliminated once the treatment system goes into place.

While an estimated 900 pounds per day enters the wash, 400 pounds per day should be removed once Kerr-McGee builds a trough to capture the ground water that is forced to the surface because of increasing runoff from the Las Vegas Valley. The area near the wash is in a low lying area that acts as a drain for the valley.

How the contaminated water will be treated once it is removed from the channel has not been determined, Biaggi said.

Perchlorate expert Brenda Pohlmann, who works in the state's Las Vegas office, said that a scientist sampling wash water for the Southern Nevada Water Authority discovered the surface channel.

Within a year Kerr-McGee plans to install a long-term treatment system for the perchlorate such as biological bugs that will remove the chemical from the water, Pohlmann said.

An evaporation pond built by Kerr-McGee in December has captured 136,000 pounds of perchlorate, she said.

Another company, American Pacific, which moved its operation from Henderson to Cedar City, Utah, is investigating sources of perchlorate, including the levels several feet underground, to see if it is reaching the wash, Pohlmann said.

How the surface channel formed is unknown, Pohlmann said. "Nobody knew this was there until about a month ago," she said.

Retired biologist Larry Paulson said it is vital to remove the perchlorate from the wash to protect the valley's drinking water.

"Nobody should have to drink it," Paulson said.