The Environmental Protection Agency is recommending that pollution from a former Macon landfill owned by Armstrong World Industries, at 4520 Broadway, be contained in place, at a cost of about $2.2 million.

“We hope to start work on the cleanup later this year and finish in 2014,” said Brian Ferrier, the EPA remedial project manager for the Armstrong Superfund site.

The National Priorities List, better known as the Superfund list, catalogues the nation’s most contaminated sites and makes them eligible for federal cleanup funds if those who made the mess can’t pay.

But as the responsible party, Armstrong will foot the entire bill for any action at its former wastewater treatment landfill, Ferrier said. He said the company has been cooperative and has already paid for an approved contractor to conduct water and soil testing at the site.

The EPA used this data in its evaluation of the extent of the contamination. Last week it completed a report that also examines the cost and effectiveness of various cleanup options.

The EPA considered three possibilities, including doing nothing and removing all the contaminated soil.

The 4-acre Armstrong landfill site in southeast Bibb County is polluted primarily with polychlorinated biphenyls, or PCBs. PCBs are cancer-causing chemicals that were once widely used by industry before being banned from U.S. manufacture in 1979.

Armstrong has manufactured acoustic ceiling tiles at its Macon plant since 1948. PCBs were identified at the site in 1996.

Jennifer Johnson, senior corporate communications manager, declined to say how much Armstrong has already paid for the investigation of the landfill. But she added, “We are committed to continuing to work with the appropriate regulatory agencies in assisting them in assessing the site and determining next steps.”

According to the EPA report, 2011 tests at the site found PCB contamination in the soil. The pollution was localized and probably caused by buried waste. Even after significant rains, PCBs were not seeping from the landfill, the report stated.

At the surface level, 19 of 55 samples exceeded the acceptable threshold for PCBs at an industrial site, and two had more than 50 times the threshold level, the report stated. A third of the underground soil samples contained PCBs, although 86 percent were at levels considered acceptable for industrial sites.

In addition, a smaller number of soil or water samples were contaminated with heavy metals, volatile organic compounds or dioxins and furans, but these were found mostly at levels considered safe for industrial land uses.

Exposures that a site worker, a construction worker or a trespasser might experience would not be expected to result in an unacceptable cancer risk or non-cancer hazard, the EPA report stated.

When it comes to groundwater, contamination was sparse and found only in the footprint of the landfill, Ferrier said.

“We do not think leeching of PCBs into groundwater is an issue,” he said.

Comment period coming up

Fish in nearby Rocky Creek are contaminated with PCBs. Ferrier said the Armstrong landfill may have contributed to that contamination in the past, but it is not doing so now.

A second, nearby landfill at the Allied Industrial Park may be a source of Rocky Creek PCB contamination, Ferrier said. There won’t be a complete investigation of that site until after it is added to the Superfund list, which is expected to happen this spring.

The EPA’s preferred approach to the Armstrong site involves putting a quarter-inch liner/cap infused by bentonite, a type of clay, over the landfill footprint. This would prevent rainwater from penetrating the soil or causing contamination to filter into the groundwater. Ferrier said bentonite offers the same level of defense as 2 feet of normal clay.

A barrier wall would be erected on the east side of the landfill to prevent erosion, the slope would be graded to control runoff, and a stormwater pipe system would be installed at the toe of the landfill.

Armstrong will also be responsible for monitoring the condition of the landfill annually, according to the report. Ferrier said groundwater testing will also be required outside the landfill periodically.

Because the contamination is not extensive and does not appear to be moving away from the landfill, EPA also considered doing nothing but monitoring the site for 30 years at a cost of about $483,000.

A third alternative, removing 62,000 tons of soil, was rejected for being much more expensive without reducing health or environmental risks more than containment would.

Removing 2 acres of dirt 15 feet deep would cost about $8.8 million and would require more than 8,000 dump truck trips to transport contaminated soil to approved landfills, the report concluded.

Ferrier said the EPA will hold a 30-day public comment period on its engineering evaluation and cost analysis -- which includes its recommended course of action -- starting about Thursday. After EPA has responded to any comments it receives, it will make a final decision and put together an “action memorandum” outlining the cleanup steps and time line.

“We hope to have that by the end of June,” Ferrier said.

To contact writer S. Heather Duncan, call 744-4225.