By: | The News & Advance
Published: May 30, 2012 Updated: May 30, 2012 - 10:10 PM
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