Water threat delays subdivision plan

Monday, Oct. 19, 1998 | 3:43 a.m.

An unknown source of low-level radioactivity that is contaminating ground water has delayed plans to build 5,000 homes in Henderson's Palm City.

The Nevada Division of Environmental Protection ordered Thursday that no home construction begin until the developer -- Rhodes Design and Development Corp. -- designs a drainage or treatment system that will protect the Las Vegas Wash, which drains the entire Las Vegas Valley.

Rhodes' development, called Palm City, is less than a mile from the wash and the wash is six miles upstream from the intake valve in Lake Mead that provides the valley with its drinking water. Home construction has not yet begun at the site, although grading is under way.

Officials fear that the development, with its golf course and home landscaping, will cause the ground water to rise, a condition that would cause the radioactivity to become more of a threat to homes and a proposed elementary school.

Historically, the area has been home to natural spring waters that have bubbled to the surface, forming wetlands.

The state will not approve any home building at the 500-plus acre Henderson site until runoff containing radiation and chemical contamination is kept off the surface and out of the wash, said Jim Williams, supervisor for water quality at the state division.

The federal Clean Water Act prohibits developers, industries or individuals from designing systems that allow drain water to run along the surface. And the state's Division of Environmental Protection requires a permit for any ground water discharging into a water supply.

Before Thursday's order delaying the construction, Rhodes Design was under the impression that it had complied with all federal and state laws and had immediate plans to begin the golf course and home construction, according to Paul Kenner, Rhodes' director of land development.

Although the Southern Nevada Water Authority says no radiation has been detected in Southern Nevada's drinking water, the state is in charge of protecting the water resource.

The Palm City development is bounded by Olsen Drive on the east, the former city landfill to the north and Sunset Road to the south.

The source of the radiation in the site's ground water is unknown. Normal daily contact with the water is not considered dangerous, but state officials say over a lifetime of exposure the water could pose a health threat.

The Nevada Division of Environmental Protection has sampled contaminated ground water running downhill underneath the development. State officials are investigating whether the runoff could be coming from the Basic Management Industrial complex uphill, once considered a Superfund site. BMI experts are also investigating the possible sources of contaminated runoff.

"It is a concern to the division," said Robert Kelso, enforcement supervisor for the state Environmental Protection Division. The state will know more about where uranium and radium found in the ground water originated once more extensive tests are completed later this month, he said.

Rhodes began grading an old gravel pit for the golf course this summer. Three years ago, its own consultant and the state warned Rhodes about the potential threat to the development from ground water and soils laced with heavy metals, pesticides and radioactivity.

The latest studies done by the developer indicate no health hazard from chloroform, carbon tetrachloride, uranium or radium found in the ground water and soils. But state environmental officials have been concerned about the ground water for more than two years.

The ground water ranges from 4 to 40 feet beneath the Rhodes site. The warnings by the state and its own consultant included suggestions to fill the area with dirt to shield residents and visitors from the contaminants. The state is still investigating the site because of those ground-water concerns.

Henderson City Attorney Shauna Hughes said the Rhodes project was stopped by the city two years ago, because the developer did not have the required environmental, health and safety studies. Since then, she noted, the developer has been responsive to every official request by the city.

Rhodes does have the necessary permits, however, to clear a 580-acre parcel in Henderson, noted city planner David Norris.

The developer was warned three years ago about heavy metals, radiation, pesticides and insecticides in the ground water flowing through the site downhill from old industrial and sewage waste ponds.

"It is recommended that the facility not be built until the standards and treatment are established," noted a report from former Rhodes consultant Terracon Corp. The report also warned Rhodes that once golf course watering began, contaminated water could rise, flowing back onto the site.

Representatives of Terracon declined comment.

The state division also told Rhodes as early as 1996 that removing toxins from water drained from the property would require a state permit to discharge into the Las Vegas Wash.

Allen Biaggi, then NDEP deputy administrator, warned Rhodes that drains from the property would require a groundwater permit and possible treatment before sending the contaminated water into the wash. "Such discharges will require an NPDES permit and may require treatment prior to introduction to the wash," Biaggi wrote to Henderson Public Works Director Mark Calhoun in May 1997.

Biologist Larry Paulson said that he does not understand how the developer was allowed to grade the property and build a tiled drainage system around the property without the discharge permit.

"The area where Rhodes is developing once had surface springs and marshes," said Paulson, a biologist and member of the Lake Mead Water Quality Forum, a group of federal, state and local water officials. Ground water laced with radioactive uranium and radium as well as chemicals flows through the site, he said.

"Rhodes should be required to have a discharge permit and not be allowed to discharge any of that contaminated ground water or storm water running off its property back to the Las Vegas Wash," Paulson said.

Rising ground water from the development may pose a threat to the homes and the proposed elementary school both from toxins and radioactivity, Paulson said.

Federal Environmental Protection Agency records dating back 15 years document toxic chemicals and radioactivity from uranium and radium in both ground water and soils. The radium could pose a radon gas threat to homeowners living in energy-efficient homes that are sealed, one report noted.

The reports on radiation risks done for Rhodes indicate about a one in a million risk of cancer from all radioactive sources for both adults and children. That is an acceptable risk under the federal Environmental Protection Agency standards, said UNLV health physicist Mark Rudin.

The risk assessment did not consider radiation exposure from ground water and failed to calculate a radiation risk from thorium, Rudin said. If the groundwater surfaced, it could pose a radioactive exposure to people and the environment, he said.

In the late 1980s, the federal EPA listed the Basic Management Industrial complex uphill from the Rhodes site and near the Henderson landfill as a possible Superfund site.

The federal EPA turned over the responsibility for cleanup of the industrial and municipal wastes to the state in 1988. But EPA's Region 9 office recently announced it may add the complex to the Superfund list because of the threat to the Colorado River from perchlorate, a rocket fuel oxidizer made at the site for 40 years. Perchlorate has been found in drinking water from Las Vegas to Los Angeles.

Besides any naturally occurring uranium or other radioactive materials, Titanium Metals Corp. is a possible source of radiation. The company uses ore containing uranium from Australia to manufacture the lightweight titanium.

Kelso wrote a memo to the state Bureau of Water Pollution Control about the Rhodes project after a site investigation in late August.

"Palm City should be aware of the potential for ground water contamination, and treat any water removed during dewatering operations accordingly," Kelso wrote on Aug. 24.

"For your information, it also appears that construction activities at this site have already commenced," Kelso noted. "Is it normal to begin earth movement prior to plan approval?"

"That was a question from us, too," said Henderson Public Works Director Mark Calhoun. Henderson did its own investigation of where the ground water was flowing. "They can keep the water on their site, but they can't discharge it.

"They're stepping out on their own nickel out there," Calhoun said.

The city of Henderson gave Rhodes a restricted grading permit in July for a portion of its development.

Rhodes' hydrology plan filed in Henderson spells out the need to meet state discharge requirements. Anyone developing over five acres of land is required to have a discharge permit.

Paul Kenner, Rhodes' director of land development, said the company was building a drain under the golf course to keep the contaminated water underground. Ground water levels have risen and may back up into the development.

A subdrain system is expected to catch irrigation water and other runoff, which would be discharged back onto the golf course. The state has issued a temporary discharge permit to install the ground water duct.

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