A Soldotna environmental firm says its method would clean an underground spill of dry cleaning fluid by the Kenai River much faster that a method proposed by the state.
The Alaska Department of Environmental Conservation proposes to drill a series of vertical wells at River Terrace RV Park in Soldotna. Through those, it would inject a product called HRC to fertilize indigenous bacteria that would reduce the dry cleaning chemicals to less harmful compounds.
"If you go with the full HRC process, you have over 200 wells drilled and it can go 15 years -- with no guarantee. It hasn't been proven to work in this climate," said Mike Wicker, manager of the environmental department at S and R Environmental in Soldotna.
DEC estimates its method would halt the flow of contaminants to the Kenai River within three months. It would clean the site within 10 years at a cost of $1.8 million to $3.9 million.
If the HRC method fails, DEC's fall-back plan is to create an underground wall of iron filings through which contaminated groundwater would flow. That would react with the dry cleaning fluid, reducing it to nontoxic chemicals such as ethylene. It would halt the flow of contaminants to the river within three months, take up to 15 years to clean the site and cost from $1.3 million to $2.9 million.
Wicker said S and R would use a more efficient method engineered by its joint-venture partner, the Canadian firm of Hobbs-Miller-Maat Inc. The cleanup would be done in a year. Depending on standards set by DEC, the cost could be as low as $399,000. The joint venture partners guarantee the results.
"It will finally put closure to the site, which everyone has been staring at for years, now," he said.
DEC first heard of the spill at River Terrace RV Park, by the Sterling Highway bridge in Soldotna, in 1992. The agency and RV park owners Judith and Gary Hinkle have long been at odds over how to assess and clean the contamination.
DEC assumed control of the cleanup in June 1997. In August 1997, the U.S. Environmental Protection Agency agreed to oversee emergency excavation of the most contaminated soil. The Hinkles excavated roughly 3,300 cubic yards from an area between the laundromat and the river, and treated that on-site.
Meanwhile, DEC kept control of long-term monitoring and assessment. In June 1999, it obtained a court order allowing its contractor, Oasis-Bristol Environmental Services, to assess remaining contamination and propose cleanup alternatives. Oasis found a new plume of contaminated groundwater flowing from the laundromat building toward the Sterling Highway. DEC made its cleanup proposal in May, following completion of the $500,000 Oasis study.
Wicker said the Hobbs-Miller-Maat method also uses bacteria. Workers would drill horizontal wells to install perforated pipes underground. One layer of pipes would lie 18 to 20 feet below the surface. Another would lie three feet below the surface. A third set would form a bioremediation barrier between the RV park and the river.
Through the deep pipes, workers would inject surfactants to loosen dry cleaning fluid from the soil, bacteria to consume contaminants and fertilizers to encourage the bacteria.
A vapor extraction system would draw air from the shallow pipes, clean it with carbon filters, mix it with air from the atmosphere and inject it through the deep pipes to provide oxygen for the bacteria.
"All this is done in Canada in the same climate, the same temperature ranges that occur here," he said.
Wicker said he has tried to submit his proposal to DEC since Dec. 9, but DEC has refused it. He finally presented it June 15, when DEC held a public meeting on its plans.
Rich Sundet, project manager for DEC, said he advised Wicker in December to contact Oasis.
"What Oasis got was a very brief document, so there wasn't much to review," he said.
After receiving the June 15 proposal, Sundet questioned the Hobbs-Miller-Maat plan to import microbes.
"There are natural bugs in the ground everywhere," he said. "People have been promoting nonindigenous bugs. The reports I've seen say to use indigenous bugs. You don't bring in nonindigenous bugs because they'll die."
He also questioned the use of surfactants.
"Any time you use a surfactant, you mobilize the material," he said. "If you free it up, it will move off-site quicker. In this case, maybe you'd move a lot more into the river."
He said he requested technical reports to demonstrate the method's effectiveness.
"That was one of the issues -- where it's been used. He said three or four places," Sundet said. "That isn't many, so it would be termed highly innovative. Any time you have something that's highly innovative, you want technical reports. He didn't provide that. What would assist us in a review is if some other agency, say the state of Indiana or the U.S. EPA, approved the process."
Sundet said the companies gave him two references, one at a university, with a request that their identities be kept strictly confidential.
A Hobbs-Miller-Maat client handbook claims its microbes have cleaned spills from northern British Columbia to Florida. Though it describes numerous projects, it omits clients' names.
"That doesn't help me at all. To me, that's just vender information. I want technical reports so I can look at results," Sundet said.
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