Whirlpool to use chemical oxidation to remove TCE

A document received by the Arkansas Department of Environmental Quality from consultants on behalf of Whirlpool details the company's plan to deploy chemicals to treat the trichloroethylene (TCE) on the company's former manufacturing site and in a neighborhood north of the site that sits on a toxic plume.

The letter, from ENVIRON Corp., said that "pilot studies" shows that chemical oxidation reduced the concentrations of TCE in groundwater. The plan, previously reported by The City Wire, is not new, though it is explained in more detail in a letter dated June 14. Though previously mentioned in a May 21 revised risk management plan, ENVIRON had not fully-detailed how the plan would work.

"The science is sound and the approach is a proven remedy," the letter reads. "There are many sites in the U.S. and Canada that use focused / targeted chemical oxidation to enhance the overall performance of natural attenuation by reducing significant mass in target areas. We are confident this approach is the best solution given the existing understanding of the site and current land uses."

A satellite image included in the document shows the areas where the chemical oxidation will take place – on the Whirlpool site itself and just north of Ingersoll Avenue and south of Jacobs Avenue, an area listed as "Area 3."

The chemical oxidation proposed in the document would involve injecting the chemicals into the polluted groundwater. In order to inject the chemical oxidation, wells will have to be put installed because "successful chemical oxidation requires the oxidant to come into direct contact with the contaminant and movement of the oxidant throughout the subsurface is extremely important."

"Therefore wells will be installed at different depths based upon the known depth of contamination and depth of the transmissive zone. All wells will be installed within the saturated zone of the aquifer."

The document continues, explaining that once the wells have been installed, piping will be connected to the wells and run to an oxidant tank.

"The oxidant tank contains the chosen oxidant mixed with a certain percentage of water per suppliers recommendation."

The process, if approved by ADEQ, would be used for both on-site and off-site injection. The on-site refers to Whirlpool, while off-site refers to the plume area where contamination of TCE, a cancer-causing chemical used as part of degreasing solutions by Whirlpool in the 1980s, has traveled since leaking from the Whirlpool site.

The document concludes by explaining that the oxidant will not just be placed in the ground, but will be "injected under pressure."

"The amount of pressure used during injection will be determined during field activities, as too much pressure could result in short circuiting (daylighting) of the oxidant. However, the addition of pressure at multiple pressure variations / cycles should assist in moving the oxidant further out into the formation, which in turn should increase the effective radius of influence at each injection well. The specific pressures and duration of injections will be field determined based on measured observations."

This addendum to the May 21 revised risk management plan is just the latest in what some Fort Smith residents and city directors feel is a negotiation between Whirlpool and ADEQ in how to clean up the site.

"It looks, to me, like it's an ongoing negotiation. They agree with some of the ADEQ's recommendations and disagree with some of it, so it's just more of the same. It's a lot of back and forth," Director Keith Lau told The City Wire on May 22, when the latest revised risk management plan was released to the public.

A call to Whirlpool seeking comment for this story was not returned.

Link here for the PDF report on the chemical oxidation process.