State officials probe major sewage spills

Nevada environmental officials are investigating four major spills of raw sewage that dumped millions of gallons of contaminated water into the Las Vegas Wash during last week's storms, six miles upstream from the area's drinking-water pipes.

The Nevada Division of Environmental Protection is expected to take more than a week to finish investigating the spills from the city of Las Vegas and Clark County Sanitation District wastewater-treatment plants, said Joe Livak, supervisor of the state's Water Enforcement Division.

Water officials said the spills currently pose no threat to drinking supplies.

The state could issue violations to the treatment plants after the investigation, he said. But the recent spills are not limited to the treatment plants. Some included raw sewage that overwhelmed transport pipes in the Las Vegas Wash and in Henderson.

Livak visited the sites of the spills Monday. "Places that didn't used to flood get overwhelmed when it rains," he said. "It's part of the development of the Las Vegas Valley. The more areas get paved over, the more flooding occurs."

In the first incident, the city of Las Vegas wastewater-treatment plant lost electricity after midnight on July 20. The power outage stopped a chlorine unit from feeding disinfectant to treat wastewater, Livak said. Normally, crews can operate the unit by hand.

"But in this fierce storm, it was too dangerous to go outside," he said. Hundreds of lightning bolts struck the valley in that storm, one of the worst in 10 years.

Raw sewage loaded with fecal coliforms from the city's plant spilled into the wash. Tests of the wash water showed 240,000 cells per 100 milliliters of water when scientists sampled the wash later on July 20. The safety standard for swimming or bathing is 200 cells or less.

The Lake Mead Water Quality Forum, a group of federal, state and local water agencies, decided to sample the water flowing into Lake Mead after the floods. The forum could post warnings for the Las Vegas Bay near a campground to prevent swimmers from getting into the water when bacteria levels are high.

The second spill occurred when a Clark County Sanitation District lift station failed during the same storm along Duck Creek in the southeast valley. The Sanitation District is building a new station to lift the sewage for treatment, but it was not ready when the July 20 storm struck the valley.

A similar incident occurred in 1996 at the same lift station during another violent storm. In that case, 487,000 gallons of untreated sewage poured into Duck Creek. The state fined the Sanitation District $7,500.

Sanitation District officials did not know how long the sewage had spilled into the wash, said spokesman Marty Flynn.

In the third spill, raw sewage from a mobile-home park near Hollywood Boulevard and Russell Road ran into the Las Vegas Wash. Livak said the same thing happened Aug. 10 of last year when a vicious thunderstorm struck Henderson.

"(The county) did a very poor job of repairing it," he said. "It will happen every time it floods unless they protect the pavement and the soils underneath."

In the fourth incident, citizens noticed raw sewage spilling from a manhole on Patrick Lane into Duck Creek. In addition, Livak spotted a pipe hidden in nearby bushes. "It apparently drains nearby streets and enters the creek," he said. But the runoff from the pipeline has eroded the channel, causing more damage and greater flooding during storms.

The contaminated runoff did not pose a health threat to Las Vegas Valley residents, who draw their drinking water from two pipelines at Saddle Island, six miles downstream from where the raw sewage entered Las Vegas Wash.

But such runoff has the potential to create dire consequences. For example, nine people have contracted the parasite cryptosporidiosis in Austin, Texas. The infection is the result of sewage spilled during flash floods there.

An Austin pumping station dumped the one-celled organism into a creek on July 14. Since then, 150 people have complained of stomach problems.

In 1994, 43 Las Vegas residents died from an outbreak of cryptosporidiosis. The Centers for Disease Control and Prevention in Atlanta investigated the incident because it occurred in one of the most modern treatment systems in the world. The CDC concluded the outbreak occurred through drinking water.

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