It's nature's equivalent of David versus Goliath. In this instance David happens to be 7 mm long and Goliath is the U.S. Department of Energy and the scientific community.
Their battleground is the Idaho
National Engineering Laboratory (INEL) in southern Idaho where
harvester ants are stymieing waste disposal efforts by doing what
ants do best - digging below and moving dirt
But this dirt is hotter than the typical
arid soil of the Snake River Plain. It contains low-level
money from the Energy Department, University of Idaho scientists
are studying methods to prevent the ants from disturbing
radioactive contaminants by digging vertical tunnels in the soil.
The tunnels allow deeper percolation of water, and more moisture
means more entry to radioactive waste.
million cubic feet of government waste is currently stored in
disposal sites at INEL, including more than 300,000 pounds of
debris from the core of the infamous Three Mile Island nuclear
plant and 1,276 pounds of plutonium, also classified as "government
Scientists James "Ding" Johnson
and Paul Blom are in the second year of a three-year study of
"biobarriers' against harvester ants. Their research tools are
plexiglass ant farms that house some 5,000 industrious ants. The
four-foot-tall farms contain four sections of pipe with different
colored soil or gravel mix. The deepest of the four levels
simulates the radioactive soil. If that particular color of gravel
makes it to the top of the ant farm, then the barrier is marked a
failure and another material is tested.
just the right substance or the exact combination of materials is
proving to be a challenge because the scientists must design the
biobarrier with other creatures in mind. In the southern desert of
Idaho where INEL is located, rodents are also
"Ants walk through cobble that can stop
small mammals, but ants can't get through gravel those same mammals
can," Blom said. "We're trying to find just how much gravel to use
and which particle size will stop the ants."
Doyle Markham, senior research ecologist at the
INEL, said the number of ant dens and the quantity of contaminated
soil they disturb are minor, but he is certain that the density of
the dens will grow if they continue unchecked. For a biobarrier to
meet waste disposal requirements set by the Environmental
Protection Agency, it must last for more than 500
Tim Reynolds, another research ecologist
at the INEL, said, "If the biobarrier is a success - and we think
it will be - this will be a resource to handle any type of waste
you can imagine, including medical, chemical and biological waste."
The lifetime of an ant colony is estimated at 17
to 50 years. Harvester ants were noticed years ago when large,
circular disks were spotted from the air - a sign of vegetation
clearing around ants' nests.
The first scientific
report of the harvester ants' presence in southern Idaho was
written in 1932. The first report of the possible threat to storage
facilities at the INEL appeared in 1991, in the Journal of the
Idaho Academy of Science.
The INEL, established
in 1949 as the National Reactor Testing Station, contains the
largest concentration of nuclear reactors in the world. Over its
44-year history, 52 reactors have been built on the 890-square-mile
site. Fourteen of the reactors are operable; the others have been
The writer is a poet and
journalist in Moscow,