Published in the Asbury Park Press
By JEAN MIKLE
TOMS RIVER BUREAU
DOVER TOWNSHIP -- Bacteria at the Ciba-Geigy Corp. Superfund site are expected to play a major role in cleanup operations there. The small microbes also will be used to help purify air -- one of the first times this has been done on such a large scale -- when the second phase of the site cleanup begins, most likely next month.
TIM MC CARTHY photoWorkmen John Finch (left) and Rob Wharton spread pine bark inside the interior of one of the filters under construction at the Ciba-Geigy Corp. Superfund site in Dover Township.
The first phase -- removal of drums from an unlined landfill on the property -- began Dec. 9 and has continued steadily. So far, more than 14,000 drums have been removed from the 5-acre drum-disposal area, said Romona Pezzella, the federal Environmental Protection Agency's remedial project manager for the site.
Pezzella said drum removal could be completed by the end of the year, well ahead of schedule. EPA officials initially estimated it could take up to two years to remove the drums. There are believed to be 35,000 to 37,000 drums in the landfill, which was closed in the late 1970s.
The drums are opened, tested to determine their contents, then shipped off the site for disposal. The offsite disposal location is chosen according to what is inside each drum -- primarily hazardous materials connected with the dye-making operations that went on until about 1977.
By next month, the second phase of the cleanup -- the excavation and treatment of polluted soil -- is expected to begin. Bioremediation, which involves using existing bacteria on the site to break down and consume contaminants, is the cleanup method chosen for Ciba's polluted soil.
Ciba Specialty Chemicals Corp., which now owns the site, is paying the estimated $92 million for the cleanup. About 150,000 cubic yards of contaminated soil will be excavated from seven sites on the property, treated using bioremediation to remove pollutants, and returned to the site. The bioremediation is expected to take four to six years.
On Friday, workers at the site were loading a mixture of pine bark, soil from the site and carbon into a 240-foot-long building at the Ciba site, off Route 37 West and Oak Ridge Parkway.
Dave Williams, Ciba's project manager for site remediation, said the mixture is being loaded into the building to a height of 5 feet 3 inches. The pile of pine bark and carbon will serve as a filter that will treat air contaminated during the treatment of polluted soil.
The microbes living in the pine bark mixture will leach pollutants in the air. Ciba officials are hopeful that up to 80 percent of the contaminants can be removed during the first stage of air treatment.
Water will be sprayed on the pine bark pile to keep it moist, a process that will have to be repeated often because air will be forced through the filtration system at a rate of 100,000 cubic yards per minute, Williams said.
Huge carbon filters will finish removing contaminants before the air is released to the atmosphere.
"Biofilters have been around for 25 years," Williams said, "but in the past they've been used mainly to remove odor, not to clean air."
The massive air-cleaning system at Ciba was designed by Karnam Ramanand, project manager for the bioremediation project.
"This has turned out very well," Ramanand said. "In the laboratory, we have been getting results of 80 to 90 percent," meaning 80 percent to 90 percent of pollutants have been removed from the air by the time it reaches the carbon filtration system.
Williams said Ciba officials would be pleased if 50 percent or more of the contaminants were removed in the first stage of air cleaning.
Pezzella said the massive air-cleaning system was designed by Ciba employees, who have been working on it for about six years.
In addition to completing installation of the air-filtration system, workers at the Ciba site are finishing several other buildings that will be used in the bioremediation process, including the massive main treatment building. That building is about 1 1/2 acres in size.
Polluted soil that is excavated will be mixed with straw and wood chips, then spread in rows in the treatment building, Pezzella said. About 7,000 cubic yards of soil can be treated in the building at one time.
A large machine called an Allu, which is basically a giant rototiller, will turn the soil piles to make sure they stay aerated. Water will be sprayed onto the piles to keep them moist. Air and water help speed up the bioremediation process.
After about five weeks in the primary treatment building, the soil will be moved outside, to a secondary treatment pad, Pezzella said. The pad resem-bles a large asphalt parking lot.
Soil will remain on the pad for about two more months to re-duce contaminants further be-fore it is returned to the site.
An observation deck has been built outside the treatment building so interested people can visit the site during the bioremediation process. A similar deck was constructed earli-er this year near the pit where drums are being removed.
The source area cleanup is aimed at reducing the amount of pollutants from the site leaching into the ground water. A groundwater treatment sys-tem, which has been in place since 1996, pumps up about 2.6 million gallons of water a day, treats it to remove pollutants and then discharges it onto land on the northeast corner of the property.
The pump-and-treat system is expected to continue for several decades.
Published in the Asbury Park Press 5/03/04
|
