Cerro Grande Fire Likely to Create Runoffs From Contaminated Areas at Los Alamos National Laboratory

*In the aftermath of the Cerro Grande Fire, which as of last Thursday, May 18, had burned at least 47,000 acres of land and destroyed more than 250 Los Alamos homes, scientists at Los Alamos National Laboratory (or LANL) are beginning to gauge the threat posed by hazardous runoffs from scorched lab property. Much of the laboratory lands have been contaminated by laboratory activities over the last 56 years. The scientists expect that burned ground soil at the Lab's Technical Areas 15 and 16, littered with high explosives, toxic metals and radioactive contaminants which are now no longer anchored by vegetation, will be rinsed out by runoffs from the annual summer storms and flushed through the lab's canyons into the Rio Grande and Cochiti Reservoir.

LANL scientists and experts from the New Mexico Environmental Department and the federal Burned Area Emergency Rehabilitation began last week to check Lab areas that have been affected by the fire for erosion. Through ground inspections and air imaging, the scientists plan to estimate the erosion potential in order to plan for the shoring up of burned areas and the protection of the city. The scientists are also inspecting many of the Lab's 1,000 waste dumps or spills, which are potential release sites for contaminants. Heavily contaminated sites which exhibit a great potential for erosion may have to be dug up or fortified by rocks, mats or hay bales. Otherwise, officials are considering employing jute matting or native seed to prevent erosion.

Erosion has been extensive in past fires in the area, as for example the Dome Fire of 1996 and the Oso Complex Fire of 1998. In these fires, heavily burned lands lost soil at rates of 100 tons per acre or more. So far, people working to contain the Cerro Grande fire have reported large, scattered splotches of intense burn on steep slopes. One Lab official said that he has heard post-fire runoff estimated at 100 to 200 times the normal levels.

Although LANL environmental officials think that the potential concentrations of contaminants are so low and so likely to be thoroughly diluted by water and eroded soils that they probably will not reach levels that are dangerous to human health, to be certain will require extensive ground inspections, tests of water and soil quality as well as computer simulations. Lars Soholt, senior risk assessor for the restoration project's SWAT team, says: "So we have low concentrations and low rates of use. Our preliminary assessment is the human risk, even under these changed conditions, hasn't changed. And we think the risk associated with the (contaminated) sediments is minimal." But Soholt adds that "it's going to take weeks to months to really clear up the picture." According to the Santa Fe New Mexican, this is the first time that an interagency team has ever dealt with a fire around and inside a nuclear site, especially one with a 57-year accumulation of contaminants.

In addition to the risk to humans, there remains uncertainty about the effects on sensitive aquatic organisms and wildlife from the combinations of various toxins that may be contained in the runoffs. Combinations of contaminants working together could damage a variety of the intertwined biological functions of an organism and make it more susceptible to illnesses. "The problem is quantifying that," says Russ MacRae, an environmental contaminant specialist for the U.S. Fish and Wildlife Service in Albuquerque. Although few houses are located in the at-risk canyons, there may be health hazards to humans who hike or mountain-bike in these canyons.

"We are really looking at some catastrophic problems for the lab and the county coming off national forest lands," says Dave McInroy, a LANL cleanup manager, in the Santa Fe New Mexican, referring to the potential contaminated runoffs.

As for concerns about air-quality, no detailed analysis of data on results from air-monitoring during the Cerro Grande Fire was available to the public as of Thursday of last week. Federal and state environmental agencies did not release specifics on what three dozen air monitors found this week and said they will wait until a detailed analysis is performed to make any statements about public health.

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