A five-year, $25 million federal cleanup removed millions of pounds of coal tar from Chattanooga Creek, but now the discovery of a creosote-like material could trigger a brand-new cleanup if the local company or companies responsible don't find a way to correct the problem.
Some state and federal environmental regulators fear a two-mile portion of the Superfund cleanup may not be adequate. A new pollutant was found seeping into the final mile of the creek bordering the former Southern Wood Piedmont facility, and the question is whether to keep monitoring the pollutant or remove its source.
"This (creosote) material is very toxic," said Craig Zeller, EPA's Superfund project manager for the creek cleanup. "The Aquablok [a quick-fix solution for the creosote seeps found during the Superfund cleanup] was never intended to be permanent. We can't let the source of this pollution threaten the cleaned up creek."
The EPA and the Tennessee Department of Environment and Conservation believe Southern Wood Piedmont, which operated a wood-preservation operation on the side of the creek from 1924 to 1988, is the source. But a company official questions those claims.
"The creek is monitored regularly. If an issue arises, it can be dealt with [then]," said Mike Cohen, a spokesman for Southern Wood Piedmont. "We're not at all ready to concede this is just a Southern Wood Piedmont problem."
Years of cleanup
In 2006 and 2007, while finishing the creek's cleanup, EPA and state crews found far more pollution than they expected and far more than could be dealt with under the scope of the Superfund plan, which covered only the creek bed.
The mandate of that Superfund action, initiated in August 1997, was to remove the coal tar that had been ditched into the Chattanooga Creek for decades by a company known first as Tennessee Products and later as Chattanooga Coke and Chemical. The coal tar was dumped in the creek before environmental laws were enacted.
One of the primary operators of Chattanooga Coke and Chemical in the World War II years was the U.S. Department of Defense. The plant burned coal to make coke, a high-heat fuel for foundries. Coal tar is a byproduct of burning coal to make coke.
The companies and parties held responsible for the creek's Superfund cleanup were the Department of Defense, Mead Corp. (owner of the defunct Chattanooga Coke and Chemical site), Riley Tar and Southern Wood Piedmont.
Riley Tar and Southern Wood Piedmont used byproducts from the Chattanooga Coke and Chemical plant to make asphalt and to preserve wood, respectively.
All four responsible parties, under the Superfund order, became the Chattanooga Creek Cleanup Committee.
When the Superfund order was written and cleanup began in the 1990s, regulators knew there was creosote on the Southern Wood Piedmont property, but didn't know it was in quantities large enough to produce the new creek pollutant.
But in 2006 and 2007, things changed.
"We would get the coal tar out of the creek and get the [creek] bed cleaned up and this [creosote-like material] would come back into it. Over and over and over," said Troy Keith, EPA's creek cleanup oversight manager with the Tennessee Department of Environment and Conservation's Chattanooga remediation office.
The creosote-like material officially is termed non-aquaeous phase liquid, NAPL for short. It didn't appear in the creek cleanup work until work was under way on the second mile of the creek, just after contractors reached the Southern Wood Piedmont property, state records show.
Both Keith and Zeller tried at the time to force the responsible parties in the Chattanooga Creek Cleanup Committee to find a more permanent fix. Southern Wood Piedmont responded to regulators that the material wasn't creosote -- it was a more liquid form of coal tar that might have come from upstream, not from its property.
Regulators countered that it was only found along Southern Wood Piedmont's property. They also noted that, while creosote and coal tar share the same 10,000 compounds, the material found seeping back into the cleaned creek was in a more-liquid form than the coal tar found anywhere else in the two-mile section of polluted creek.
Cohen acknowledged Thursday that the material has been detected in Southern Wood Piedmont property monitoring wells "only occasionally and in very small amounts." He said it has not been detected in the creek since the application of Aquablok in the cleanup.
The Aquablok was applied to the sides and bottom of the creek for almost 6,000 linear feet. It added nearly $4 million to what was expected to be an $8 million, second-phase cleanup. The creek's first-phase cleanup, from 1997 to 1999, cost $12 million.
To create a more-permanent fix, Keith and Zeller recommended a passive underground drain be used in conjunction with the Aquablok. They felt pressure from the seeping creosote on the Aquablok seal would be relieved, helping it last longer, if the creosote could flow through a drain system to areas that could be monitored and periodically pumped for appropriate disposal offsite.
"At that point, the creek was wide open -- like a patient in open-heart surgery," said Keith. "Why not then put in this drain system?"
Zeller and Keith said the Chattanooga Creek Cleanup Committee discussed that fix, which would have cost about $250,000 to install. But talks broke down when Southern Wood Piedmont representatives said they would agree only if the other parties also agreed to pay for the eventual monitoring, pumping and disposal costs. None would, according to officials.
At 4:30 p.m. Monday in Nashville's TDEC office, a public comment period ends on a proposed modification of Southern Wood Piedmont's hazardous materials management permit under the state's Division of Solid Waste Management.
Although not directly connected to the Chattanooga Creek cleanup, the permit could impact whether future cleanup of the creosote material takes place.
The Division of Solid Waste Management is the state enforcement arm of the federal Resource Conservation and Recovery Act, which controls hazardous waste at all stages from generation to transportation, treatment, storage and disposal.
In the state and federal governments, the Resource Conservation and Recovery Act oversight is separate from the remediation and Superfund divisions.
In 2005, Southern Wood Piedmont's permit for the Chattanooga site was renewed with a provision that acknowledged "the need for further corrective action" on the company's property to be evaluated after the Superfund cleanup was complete.
The wording of Southern Wood Piedmont's proposed permit modification would allow the company to monitor the material seeping into the creek and place deed restrictions on its 155 acres, without doing any further remediation.
The head of TDEC's Solid Waste Management office, Clayton Bullington, declined comment.
TDEC spokeswoman Tisha Calabrese-Benton said nothing has been decided yet.
"The department is receiving comments from EPA and plans to have discussions with EPA prior to anything being finalized," she said.
Both remediation and Superfund divisions of EPA and TDEC plan to oppose just a monitoring stance, according to Keith and Zeller.
"There needs to some removal of this [pollution] source material," said Keith.
Several million dollars in taxpayer money -- including $10 million from the Department of Defense -- already has been spent to clean up the creek, Zeller said.
"We have to keep this (pollution) from coming back through our $12 million remediation, Zeller said.