Cracks at landfill may taint water

Earthquake faults and cracks at Sunrise Mountain landfill could threaten the Las Vegas Valley's drinking water, a preliminary Bureau of Land Management report says.

Scientists do not know if the faults and cracks allow water to flow through the landfill, emptying two miles downhill into the Las Vegas Wash, which leads to the valley's major drinking water source, Lake Mead.

The complex site needs more study before scientists can begin drilling wells into the mountain to track the ground water.

Brent Lewis of the BLM's National Applied Resources Science Center in Denver met with state and county officials last week after studying the closed landfill.

Nevada, Clark County and former landfill manager Silver State Disposal Co. are planning to monitor the ground water at Sunrise.

The Frenchman earthquake fault slices through the center of the 760-acre landfill site. Lewis discovered other faults and cracks in the alluvial fans, skirting the base of the mountain east of the Las Vegas Valley. "That complicates things," he said. Alluvial fans are deposits from erosion of the mountain.

The Nevada Division of Environmental Protection will coordinate ground water studies with the Clark County Public Works Department, the Clark County Health District and Silver State Disposal Co.

Les Gould, supervisor of the state's solid waste bureau, said NDEP will assist the county and the company with guidelines for a water quality monitoring plan.

The BLM has offered its staff to conduct the ground water monitoring. "Everybody agrees there needs to be wells out there," BLM landfill project manager Michael Moran of Las Vegas said. The question is where to begin drilling them for the best picture of the mountain's flows.

Earlier studies by BLM consultants found cracks, one 100 feet long, in the landfill's cap. BLM officials and Silver State dispute who is responsible for correcting the problems at the landfill.

The BLM owns the landfill property, but leased it to Clark County in 1962 as a municipal dump site for the Las Vegas Valley.

The health district has installed an air monitor at the landfill to measure hydrogen sulfide gases. Homeowners living about a mile west of the site have complained of a rotten egg odor.

So far, the health district monitor has measured gas levels about 100 parts per billion, compared to 10,000 parts per billion set as the amount affecting health.

Methane gas, common to all landfills, will be studied if Congress approves $250,000 in its 1999 budget. The budget passed the Senate Energy and Natural Resources Committee late Thursday night.

The Sunrise landfill cap cracked because the clay mixture required by federal law swelled when it became wet, then shattered as it dried.

The federal Environmental Protection Agency is overseeing research by the Desert Research Institute in Reno and EPA Cincinnati's Office of Research and Development to find alternative covers that keep old landfills intact.

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