By: | The News & Advance
Published: May 30, 2012
The Environmental Protection Agency said this week it supports
Altavista’s plan to let nature loose upon the toxins deposited into the town’s
wastewater treatment pond nearly 40 years ago.
“We support innovative explorations for finding solutions to
the problems, like the one that exists in Altavista, as long as it is sound
science and it is protective of both the environment and humans,” said Steve
Rock, an environmental engineer for the EPA.
“And we think this program is both.”
The fact that the federal agency supports deployment of
bioremediation methods marks a fortuitous turning point for a town that has
spent more than $160,000 and more than a decade searching for the least-costly
method to remove polychlorinated biphenyls, or PCBs, from the pond just 300 feet
from the Staunton River.
In March, the state Department of Environmental Quality
reiterated its position with town officials that the “green” technology was
unproven and Altavista needed to meet the 2014 PCB removal deadline agreed upon
in a voluntary remediation program.
State officials favor the traditional “dig-and-haul” method to
a PCB-certified landfill, which is estimated to cost about $4.5 million and
still leaves the town liable for the contamination.
Rock, along with two other researchers, is expected to publish
the scientific backing this summer for at least two of the bioremediation
methods Altavista will employ this year —phytoremediation and activated carbon —
in the EPA newsletter, “Technology News and Trends,” which addresses remediation
technologies.
On Tuesday, scientist Louis Licht, founder of Ecolotree Inc.,
and town employees began gingerly pushing poplar and willow tree cuttings into
the soft soil on four test plots the town created along the edge of the six-acre
pond.
While lab tests tell Licht these trees will take root and —
over several years — break down the components that make up the PCBs and remove
them from the environment, he needs a field study to test the theory.
Researchers said Altavista is the perfect petri dish for
several reasons: town leadership supports innovations, the pond is completely
contained and the site has no other contaminants.
Typically, PCBs exist in concert with other chemicals. But in
this case, the site has been tainted for so long that all other contaminants
already have broken down, allowing scientists the rare opportunity to work
solely with PCBs.
If Licht’s theory holds true, once the town has capped the
pond with soil and planted thousands of trees, the PCBs will literally degrade
in place. According to Licht, the cuttings will establish an extensive root
system throughout each test plot, which sits on top of the contaminated pond. As
the trees grow, fed by the pond water and sunlight, the microbes in the root
system will break down the chemical compounds that make up the PCBs,
mineralizing them into inert compounds.
Some experts estimate it could take three to five years to
break down PCBs in this manner.
Town officials started phytoremediation efforts in earnest
this month. Town Council approved about $30,000 for the first phase of study,
and this month employees relocated about 200 cubic yards of dirt from English
Park to the pond. Employees created four small islands along the side of the
pond, mixing in leaf compost and poultry litter to the mix. In Phase II, crews
will build tree planting plots atop the areas of the pond with the highest PCB
concentrations.
Concentrations in the pond range from 1.4 to 6,900 parts per
million, according to a Human Health Risk Assessment done on the site in 2010.In
theU.S., anything higher than 50 ppm requires remediation.
“We’re watching with great interest to see how it works,” said
Rock, who visited the town in March to talk about plant-enhanced
bioremediation.
“We have a sense that the process works; what we don’t have a
sense of is the rate and extent,” he said.
On Tuesday, Licht estimated the right three-year program could
make an impact. The key element is time, which is the lynchpin for the state
DEQ. Officials with the state agency, who did not return phone calls seeking
comment, have been working with Altavista for the last 10 years to find a way to
remove the PCBs
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