Until now, most of the cleanup at the former Kerr-McGee creosote plant in the Memphistown area of Columbus has focused on excavating and removing contaminated soil near the surface at the portion of the 90-acre property north of 14th Avenue.
But much like the wounds the community suffered as a result of the environmental crisis, the damage goes much deeper.
On Tuesday, Lauri Gorton of the Greenfield Environmental Multistate Trust and Charles King of the Environmental Protection Agency used a pair of Zoom town hall meetings to update citizens on the progress while devoting much time to talking about other options for cleaning up the contamination that is too deep for removal by excavation.
“We have several alternatives that we have identified,” said Gorton, project manager for the Trust. “We will look at time and compare and evaluate them using EPA criteria. No decisions have been made on which options or combination of options we’ll use.”
Gorton said areas of the site that can’t be excavated and removed will rely on two other strategies — treatments that will make the contamination less toxic along with containment and capping measures to keep the contamination from moving or coming into contact with people.
“Everything being considered is for the protection of human health and the environment,” Gorton said.
One of those possible options relies on Mother Nature through something called phytoremediation — planting trees in contaminated areas to soak out contamination from the water table deep below the surface that will form a natural barrier to keep the contamination from spreading beyond the tree line.
Even as Gorton and King were holding their Zoom meetings, Jim Landmeyer, research hydrologist with the U.S. Geological Survey, was overseeing the planting of 2,500 hybrid poplar trees — 2,000 along the southwest section of the site where the main creosote operations were conducted and another 500 in a section north of 14th Avenue in an area called the Pine Yard, which was used by the plant for the storage and shipping of finished creosote products.
“We are doing a test right now to see if phytoremediation is something that we can use for part of the remedy in Columbus,” Gorton said. “Trees are Mother Nature’s pumps. They pump out groundwater and provide a nice natural barrier to keep the contamination from moving beyond the tree line.”
Hybrid poplar trees, selected for their fast growth, deep root system and resistance to disease, are being used in what King called a “pilot program.”
“Experts have told Lauri and I that within two years, the trees should be pumping a reasonable amount of water out of the soil,” said King, the EPA’s project manager in Columbus. “By the end of the first year, we should see some indication of whether it’s working. How much of a role phytoremediation will play in the cleanup, I’m not going to speculate about. I do know we are not going to just depend solely on phytoremediation. If it’s something that can be used here, it will be one of a combination of technologies we will use.”
Other technologies being studied are biosparging, pumping air into the contaminating areas that breaks down the contaminants over time, slurry walls that act as barriers to prevent the spread of contamination; and stabilization, which pumps concrete that mixes with the contamination and sets to trap the contamination in giant blocks.
“Every one of these have been used at other Superfund sites,” Gorton said. “They are not experimental in that sense. At the same time, not every technology is effective at every site. So we’re in the process of evaluating which technologies will work in Columbus. At that point, we’ll make our recommendations to the EPA for their approval.”
In 2015, the EPA declared the Kerr-McGee site as a Superfund site, awarding more than $60 million for environmental action around its former Kerr-McGee location, where the company and its successor, Tronox, used creosote to treat the railroad cross ties produced at the plant from 1928-2003. Creosote is a chemical used to preserve wood that, according to the U.S. Agency for Toxic Substances and Disease Registry, can cause skin and eye irritation, stomach pains, liver or kidney problems and possibly cancer.
Many Kerr-McGee employees in Columbus, along with residents in surrounding neighborhoods, developed health problems linked to creosote exposure.
As for ongoing cleanup efforts, mostly confined to excavation and removal of contaminated soil, Gorton said about 90 percent of the excavation/removal in the 44-acre Pineyard area has been completed. Ditch cleanup and installation of concrete liners should be completed by the end of the year.
“The ditch that’s remaining to be cleaned out is between Marvin and Moss streets,” Gorton said. “We are hoping to get a little cooperation from Mother Nature on this. We probably would have been done with that work if not for all the rain and severe weather Columbus has received.”
Gorton said about 70 percent of the cleanup/concrete liner work has been completed.
Finally, she said 11 parcels outside the original plant have been identified for cleanup.
“There were a total of 96 properties that were sampled in the neighborhoods around the site,” Gorton said. “Of those 96 sites, 11 were eligible for cleanup. On two of those properties, the cleanup has already started and work on the others should be starting in the next few weeks.”