Lab confirms unsafe perchlorate levels in wash

Tuesday, Aug. 26, 1997 | 10:09 a.m.

A California laboratory has confirmed that perchlorate, a chemical used in rocket fuel, exists at unsafe levels in water flowing into Lake Mead.

But Montgomery Watson Laboratories of Pasadena, a lab certified by California to test for perchlorate in water, discovered lower levels of the chemical than an uncertified lab in Las Vegas. The labs used the same samples.

The Nevada Environmental Protection Division reported Aug. 18 that perchlorate had been discovered in samples from the Las Vegas Wash, the valley's main drain, at levels 100 times higher than safe for drinking.

Lockheed Martin Environmental Services measured 1,680 parts per billion of the perchlorate west of Lake Las Vegas, a man-made lake in the wash. The California lab found 1,400 parts per billion at the same location.

Montgomery Watson scientists reported decreases in the chemical up and down the wash. A sample taken between the Las Vegas and Clark County sewage treatment plants was 47 parts per billion of perchlorate. Pasadena's results were 20 parts per billion.

The differences in results taken from the same water samples come from the relatively new procedure and the fact that salts in the Las Vegas Wash water interfere with levels of perchlorate, said Kay Brothers, director of Southern Nevada Water Authority Resources.

No perchlorate levels above a California guideline have been detected in samples taken from raw or treated Southern Nevada drinking water.

Perchlorate is not regulated by federal or state drinking water laws in Nevada. California has set a guideline of 18 parts per billion, and has closed 18 wells since the chemical was discovered in Southern and Northern California in April. The substance has normally been found near rocket fuel manufacturers and explosives plants.

The U.S. Environmental Protection Agency is studying perchlorate, because it is used to treat people with Graves disease to regulate their thyroid glands. In thousands of parts per billion, it can disrupt growth and bodily functions because of its effect on the thyroid gland. Perchlorate is also fed to steers to fatten them for market.