Radiation levels raise flags for developers

Wednesday, Nov. 11, 1998 | 11:09 a.m.

An advisory committee on water is asking why Henderson and Clark County are allowing housing developments to continue near the Las Vegas Wash until sources of radiation and chemical contamination are identified and cleaned up.

Two major housing developments planned by Saxton, Inc., and Rhodes Design and Development Corp. could change the flow patterns and increase concentrations of contaminated water running into the wash, experts said during a meeting Tuesday night.

The valley's water quality could become poorer from higher runoff from lawns and golf courses, members of the Southern Nevada Water Authority Citizens Advisory Committee said.

"We acknowledge there is a concern to the community from a drinking-water standpoint," Paul Kenner, manager of land development for Rhodes, said.

Rhodes is developing a community and golf course on 600 acres of land in an old gravel pit. Consultants hired by the developer discovered radioactive ground water and soils underneath the property. The depth of the ground water ranges from 3 feet to 70 feet below the surface, Kenner said.

"You may not realize it, but the lower end of your project will be under water with all the runoff," Larry Paulson, a biologist and committee member, said.

The Las Vegas Wash drains surface and ground water -- some of which contains chemical runoff and radioactivity -- from the valley into Lake Mead, Southern Nevada's major source of drinking water. While higher-than-expected levels of radiation have appeared in the valley's drinking water, no one knows what is causing the measurable increase.

Naturally occurring radioactive rocks or industrial wastes dissolved in ground water are possible sources that state environmental officials are studying. Currently, drinking Lake Mead's water poses no health threat, the experts said.

The county is trying to build 15 structures in the wash to slow flows and restore 2,000 acres of wetlands.

The more developers contribute runoff to the wash, the harder it will be for Clark County to develop the wetlands to help clear the pollution from drinking water, Paulson said.

Further development in the 15-mile Las Vegas Wash could cause rising ground water to either crack or dissolve housing foundations, said Jeff van Ee, a federal scientist who also serves on the committee.

Rhodes is developing alternative plans to meet tough standards set by the Nevada Division of Environmental Protection, Kenner said. The developer is planning to route water containing radioactivity, chloroform and carbon tetrachloride in a below-ground channel so that it flows into clay soils 200 feet from the wash.

However, the Nevada Division of Environmental Protection has delayed home development at Rhodes' Palm City project in Henderson and could stop any discharge from the property south of Lake Mead Drive, said Brenda Pohlmann, who is in charge of water quality at the state's Las Vegas office.

"The state's potential concerns are elevated radiation levels and the chemicals that need further evaluation," Pohlmann said. The state's own water samples show elevated radiation from uranium and radium in the ground water, she said.

The state is waiting for Titanium Metals Corp. to complete an extensive study of radioactive sources from the old Basic Management Inc. industrial complex, Pohlmann said. The chlorine process used by Timet produced a water-soluble radium in sludge that produces higher concentrations of radium.

State environmental officials will present their latest findings at a public hearing scheduled for 7 p.m. Dec. 1 at the Henderson Convention Center on Water Street.

Saxton was not represented at the meeting.