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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