Groundwater contamination forcing new cleanup at Atlanta Gas Light site

Atlanta Gas Light Co. has found new contamination and is working on a new cleanup at the site in Macon’s industrial district where a manufactured gas plant once generated light for Macon.

The cleanup had been deemed complete in 2002 after more than 100,000 tons of soil and debris were removed, and only continued monitoring was required. But more contamination affecting groundwater was found, and the current work is scheduled to last until February, said Tami Gerke, an Atlanta Gas Light spokeswoman.

In 2006, the Macon-Bibb Urban Development Authority bought the property, which covers a block from Mulberry to Walnut streets and Sixth to Seventh streets.

“We bought it because we thought it was such a crucial and critical piece of downtown,” said authority Chairman Bob Lewis. “We’ve had several people indicate an interest in developing it, but they don’t want to do anything until the final remediation is complete.”

He and Sid Cherry, the authority’s executive director, said the authority has been approached by a couple of companies interested in building stores with extra storage space for inventory, as well as an Atlanta–area group that builds skate parks.

Bill Causey, director of the city engineering department, said a portion of the property could be reconfigured as part of an effort to realign the intersection of Walnut Street and Seventh Street so heavy truck traffic could be shifted to Seventh from Martin Luther King Jr. Boulevard. Cherry said the authority supports the idea.

The additional contamination was found on the property a little more than a year ago, after the authority purchased the property, Cherry said. But the purchase stipulated that Atlanta Gas Light would be responsible for pollution there.

The additional contamination was found as the company installed a new well to monitor groundwater, Gerke said.

The cleanup involves removing a top layer of soil, then mixing saturated soil near the water table with a cement mixture. This binds pollution in place and prevents groundwater from moving through it, according to Atlanta Gas Light documents.

Sidewalks and curbs will be removed, then restored when the cleanup is done, Gerke said.

Cherry said Atlanta Gas Light contractors told the Urban Development Authority in July that this cleanup phase is expected to be the last “ground-breaking action” necessary.

People who work near the property may be affected by noise, dust and a possible odor from the cleanup site, according to Atlanta Gas Light.

Kevin Collins, an Environmental Protection Division geologist and compliance officer for the site, said future development on the property can’t disturb the mass of solidified contaminants created to contain the pollution. That mass is currently about 30 feet below the surface and covers about 60 percent of the block, Collins said.

The process of manufacturing gas from the 1870s to the 1930s produced about 20 hazardous contaminants related to the coal tar that was a by-product of burning coal to produce gas.

Among the pollutants were lead, cyanides, arsenic and benzopyrene. Many of the metals can be toxic to people who regularly have direct contact with them, and many of the other chemicals can cause cancer.

Most of the same pollutants are the subject of the current cleanup, Gerke said.

Collins said there are two major elements to the contamination: benzene and naphthalene from the old coal tar, and a separate plume related to diesel fuel.

Collins said safe future uses for the property can’t be determined until Atlanta Gas Light completes its investigation of the contamination.

Information from The Telegraph archives were used in this report. To contact writer S. Heather Duncan, call 744-4225.