Study will look for ways to protect water supply

Wednesday, Feb. 27, 2002 | 9:57 a.m.

A new study by the Southern Nevada Water Authority and other agencies will try to find a way to remove potentially dangerous chemicals that get into water supplies from daily household waste water.

Environmentalists and scientists have warned for decades that chemicals in treated waste water that is returned to water sources -- from pesticides to traces of birth control -- could have powerful effects on the environment.

"This is an emerging issue," David Rexing, authority research and development manager, said. "There aren't a lot of answers, but there are a lot of questions."

The water authority, the major supplier in the Las Vegas Valley, will receive more than $1 million to conduct the study. It will work with the Louisville Water Co. in Kentucky, Arizona State University, Black and Veach environmental engineering consultants in Missouri and United Water, a New Jersey-based, for-profit water company.

Also participating in the study will be the cities of Cincinnati, Kansas City, Mo., and the Metropolitan Water District of Southern California.

One question the 27-month study won't answer is the effect that hormone-disrupting chemicals have on animals in the water, on land or the air. The federal Environmental Protection Agency is the lead agency investigating those effects.

Scientists have linked the chemicals to "hormone-dependent cancers, reproductive tract disorders and reduction in reproductive fitness," according to the research project abstract.

One of the study's goals is to define what is and is not an endocrine disrupter, or chemicals that disrupt the hormone system, Rexing said. For example, perchlorate -- a contaminant from rocket fuel -- has been found in water leading to and in Lake Mead. The chemical is a suspected endocrine disrupter.

Rexing said there is no evidence to suggest that perchlorate or other dangerous chemicals are reaching the taps in people's homes in Clark County. But the water authority -- and similar water agencies nationwide -- need to know what technology can successfully remove even tiny traces of such chemicals, he said.

"We do not find them in the drinking water, but we want to be able to continue saying this," he said. "We want to be able to say we can take them out, and how much we can take out."

Rengao Song, one of the study's principal researchers, said the data on the environmental impact of endocrine disrupters isn't clear. The effects, if any, are likely greater on wildlife than on the human population, he said.

"Whether or not they have any effect on the environment, we definitely need to know what we are dealing with," said Song, who works for the Louisville Water Co.

While the chemicals aren't present in the drinking water in detectable levels, according to water authority officials, they are in the Las Vegas Wash and other streams that feed into Lake Mead. A possible application of technology studied in the research would be treating water that flows into the lake, Rexing said.

Klaus Stetzenbach, director of the Harry Reid Center for Environmental Studies, agrees that there are more questions than answers on hormone disrupters in water supplies.

Studies such as the water authority's can help provide some answers, he said. Water systems might need to use the information if they detect high levels of contamination, he added.

"Research is always a good idea," Stetzenbach said. "You'd like to stay ahead of the problem, and I think that's what they're trying to do with the research here."

The study is being paid for by the American Water Works Association Research Foundation, which represents thousands of water agencies and companies nationwide, and other agencies and companies nationwide.