Thursday, December 04, 2003
Copyright © Las Vegas Mercury

Thirsty for information

How much perchlorate in the water is safe? The government doesn't know

By Larry Wills

A federal study has confirmed earlier reports that rocket fuel chemicals from Henderson industrial plants are contaminating the nation's food supply. The study by the Department of Agriculture shows that lettuce grown along the lower Colorado River is particularly susceptible, with accumulations of the contaminant perchlorate far above the limit suggested by the Environmental Protection Agency.

Just what kind of health hazard that might pose is being debated, since the EPA has yet to rule on what concentrations of perchlorate are safe. Perchlorate has been linked to thyroid and endocrine damage, with pregnant women and children particularly at risk.

Levels of perchlorate, a chemical used in rocket fuel by the Defense Department, reached 80 parts per billion in leafy and Romaine lettuce in six of 10 samples gathered for the study. The EPA has been considering the safety level at less than 20 parts per billion.

"It's basically leafy greens," Allen Jennings, USDA pest management policy director, says of the contaminated plants. "We're not finding it in carrots and onions. The main objective of our study was to see if other fruits and vegetables had potential levels."

But mustard greens, melons and milk have reportedly yielded levels of perchlorate in other studies. Jennings insisted the data from Southern California, which is the nation's largest supplier of winter lettuce, was not alarming. "We're not seeing that ability to accumulate that we saw in samples last year and in March and April," he says. He says contamination levels were about 30 parts per billion, where earlier lettuce tests reached as high as 80 parts per billion.

He conceded that perchlorate as a salt cannot be washed off the vegetables, since it ends up in the plant's tissues, but doubted it posed a health threat. "It's still a healthy diet, certainly until we know more."

Jennings says the Food and Drug Administration is planning more detailed tests on the crops along the Arizona-California border. That agency also has not imposed permissible limits on perchlorate contamination. "They'll be using more sensitive analytical methods," Jennings says.

But that's of little comfort to Eric Wesselman, a California Sierra Club official who's tracked the contamination and who plans to issue a report after the first of the year. "We will provide more information on this subject," he says. "In a few months, we'll find out how bad this situation is. Is it good or bad to have rocket fuel in our bodies? There's a huge need for a federal standard, since this lettuce is being shipped all over the country."

Wesselman says he's waiting for the public indignation over the contamination that affects the entire lower reach of the Colorado River. "Public reaction haven't started yet. Someone's going to discover, `My God, there's rocket fuel in the water.' You cook with it, you bathe in it. They'll be amazed to find out no one's doing anything. The drinking water is just as alarming."

Since the perchlorate goes into solution with the water, ordinary municipal treatment plants can't take it out. Only an expensive process called reverse osmosis can. "I'd like to see a study on how many people purify their water with reverse osmosis," Wesselman says.

J.C. Davis, spokesman for the Las Vegas Valley Water District, agrees that reverse osmosis isn't practical on a large scale. "It's a remarkably wasteful technology. It takes five gallons of water to make one," he says of the process.

Perchlorate in Lake Mead is ranging from 8.2 to 9.8 parts per billion, he says, or about half the EPA's suggested limit. But he admits simply waiting for the leaching to stop isn't the answer. "Left to its own devices, it would take a long time. And that doesn't do anything for the people downstream. The goal of everyone concerned is to maximize removal of the perchlorate before it enters the lake. We have to rely on remediation."

That's what Kerr-McGee Corp. has been doing for six years. It's been drilling wells along the Las Vegas Wash and intercepting the perchlorate before it enters Lake Mead and thus the Colorado River.

Pat Corbett, Kerr-McGee's director of environmental affairs, remediation and planning, says, "We have been treating it with an ion exchange since 1999 and are about to commission a biological remedy."

Corbett says his firm has spent $80 million on the cleanup since 1997, even though most of the rocket fuel was manufactured before Kerr-McGee took over the facility, which dates from World War II. The Navy owned the plant from 1951 to 1962, when perchlorate emerged as a key ingredient to propel rockets. Corbett says the federal government has not funded any of the cleanup work. And the plant may not be the only source, since other sites at the BMI complex are also suspected polluters. "The preponderance was produced under other ownerships," Corbett says.

Corbett believes the perceived danger may be overblown. "Perchlorate was once used as a prescription drug to treat hyperthyroid," he says. Those dosages were many times what's occurring in the Colorado River. A Kerr-McGee study of employees who worked with the chemical identified no health effects.

Jim Najima, chief of the bureau for corrective action at the state Division of Environmental Protection, denies there's any proven health danger from the level of contamination. "No one has seen any health effect," he says. And he says Kerr-McGee's cleanup work has been effective. "We are fairly confident that we are capturing most of it. Some things may be getting past. We are working diligently."

Najima says little will be known about the health effects until federal agencies set safety standards. "As environmental regulators, we depend on the public health folks to establish those parameters."

California, already alarmed at the contamination levels, is not waiting for a federal standard, but will set its own, Wesselman says. "The California standard may be between 3 and 6 parts per billion," he says. If that happens, the Colorado River water would be in compliance at 5.1 parts per billion, but the contamination of Las Vegas drinking water would be about 50 percent over that standard.

He also worries that the Bush administration's proposal to exempt defense facilities would mean bad news for any cleanup efforts. "The Department of Defense is mucking around with EPA standards," he says. "The DOD reportedly believes the perchlorate limit should be 200 parts per billion."
`The Department of Defense is mucking around with EPA standards.'

--Eric Wesselman, a California Sierra Club official who has tracked perchlorate contamination.

Note: Larry's suggestion is to use file art of Las Vegas Wash.

For six years, Kerr-McGee Corp. has been drilling wells along the Las Vegas Wash to intercept perchlorate before it enters Lake Mead and the Colorado River.