Monday, April 6, 1998 | 10:19 a.m.
Home and hotel owners alike have paid for treating their wastewater through pipelines linked to one of three local plants.
As a result of the Clean Water Act, the treatment plants in Las Vegas, Henderson and Clark County have spent millions of dollars to improve the water quality of their discharges. Each plant operates under a permit approved by the state.
Treated sewage flows into the Las Vegas Wash and enters Lake Mead, which supplies 90 percent of the valley's drinking water. The treatment plants' discharges are called "point sources" and they are only part of the water quality problem.
Lake Mead faces an onslaught of contaminants washing off parking lots, golf courses, lawns, construction sites and a shallow aquifer formed underneath the Las Vegas Valley as it continues to grow. These are labeled "non-point" sources, because no single owner takes the blame for them.
The federal Environmental Protection Agency is developing guidelines that give states eight to 13 years to develop a standard for each stream and water source, such as Lake Mead, fed by non-point sources. In Nevada there are 56 of them, compared to 560 in California, 870 in Oregon and 960 in Idaho.
The Lake Mead Water Quality Forum plans to monitor these unidentified runoffs. The group, formed more than a year ago, draws members from federal, state and local drinking water suppliers, wastewater treaters and regulators.
Non-point pollution sources are not subject to direct government regulation under the Clean Water Act. In contrast, federal and state regulators can levy up to $25,000 a day in fines against a sewage treatment plant if it violates its discharge permit.
Regulators rely on voluntary efforts by landowners to control non-point sources. Where contamination such as bacteria, solvents and pesticides are so widespread, finding those responsible is nearly impossible.
So the Lake Mead Water Quality Forum will begin to find out where these unidentified contaminants originate.
This difficult task goes to David James, an associate engineering professor at UNLV, who will team up with biologists to identify the unknown sources contaminating the Las Vegas Wash and Lake Mead.
Although the wash is formed in an urban setting, it is a natural water body that attracts ducks, grebes and other water-loving birds. Up to 250 species have been observed feeding and nesting there. The fact is, they foul the water, James said.
Although the local treatment plants have done a good job cleansing wastewater, people, animals, birds -- all warm-blooded animals -- contribute fecal coliforms to the local waters, explained Debra Bolding, City of Las Vegas treatment plant director.
The treatment plants test for coliforms because they are so common and they can indicate disease-causing bacteria such as typhus, she said. Between 1995 and 1997 coliforms in the Las Vegas Wash above the treatment plants have been higher.
The water quality forum also is considering tests of the Muddy and Virgin rivers, which feed Lake Mead and the wash, to track down other sources of the coliforms.
archive
