Water supply could be in danger

Friday, Jan. 9, 1998 | 10:09 a.m.

Southern Nevada experts have a new worry about Colorado River water quality.

A gradual change of the hydrogen content is under way that could throw the river's water out of balance, creating havoc among fish, growing plants and drinking supplies.

Scientists have charted the imbalance over the past 30 years in samples taken along the Colorado River. The change may possibly be due to increased pollution, although scientists have not yet determined a cause.

For water to be the best in quality, there must be a delicate balance between hydrogen ions and hydroxide ions. The balance is measured using what is known as the pH scale.

Most people know the pH scale as revealing either acidity or alkalinity. The lower the number, the more acidic the solution. Vinegar, for example, is a 2 on the scale.

A 7 on the scale means the water is balanced and considered neutral. But Colorado River water has changed from 7.5 to 8.5 on the pH scale, meaning fewer hydrogen ions that could cause an upset in water quality.

The Southern Nevada Water Quality Forum is considering the rise in the pH level as a future topic to explore in Lake Mead, the Las Vegas Wash, and below Hoover Dam.

The forum consists of federal, state and local agencies along with environmentalists and industrialists concerned about Southern Nevada's water quality. Formed a year ago, the forum has allowed agencies to share information on drinking water, wastewater, contamination and other problems.

Those attending the forum Thursday at the Las Vegas Valley Water District seemed eager to look for more information.

The reason scientists worry about rising pH levels is the effect of ammonia on fish. Fish don't thrive above pH 9 and higher pH levels combined with ammonia threaten the fish. There has already been a fish kill when the pH reached 10 near Green River, Utah, in the past decade.

The question for scientists to answer is what will the pH in the river be in another 30 years.

If it continues to rise, more fish kills could occur on the Colorado River.

"The trend in the pH level is going up, especially in the Upper Colorado," said Bill Burke, a biologist with the National Park Service.

Park Service toxicologist Roy Irwin of Fort Collins, Colo., said it's too soon to tell what is causing the shift in the pH scale. "There's enough anecdotal evidence to start looking at it," he said.

The U.S. Geological Survey has been keeping records along the lower end of the river for 25 years and that will be one source for scientists to begin studying pH trends.

Possible increases in the pH scale could come from more urban runoff. There are more lawns, golf courses, parks and other surface runoff picking up fertilizers and the desert's alkaline soils. Industry may also be contributing to the shift in the water's balance, experts say.

The jump in pH, however, may be nothing more than differences in monitoring techniques and instruments used to measure water samples, said James LaBounty, a water expert who has studied a polluted plume of water running from the Las Vegas Wash and through Lake Mead for years.

The U.S. Environmental Protection Agency also offered a small grant to the group for a water quality project.

Capt. John M. Moore, acting director of the EPA's National Exposure Research Laboratory in Las Vegas, said President Clinton announced a new program to offer citizens clear, simple information about environmental and health risks to their families.

Called EMPACT, for Environmental Monitoring for Public Access and Community Tracking, the EPA is leading the cooperative effort with the National Oceanic and Atmospheric Administration and the USGS.

Las Vegas has been chosen as one of 86 cities to conduct an interagency pilot project on air and water pollution and radiation monitoring, Moore said.

The EPA chose cities across the nation. Moore said the 75 largest U.S. cities with 166 million people contain more than two-thirds of the nation's citizens.

Grants between $30,000 to $70,000 are available for this year, he said. Moore encouraged the forum to develop a proposal and apply for a grant to study water quality.

Government agencies are the worst at delivering scientific information in a clear and concise fashion, he said.