Full-scale chemical oxidation treatments of a chemical plume in south Fort Smith will not happen until Spring 2016 while a soil monitoring station will be installed in an occupied residence. The two items were revealed in the latest report filed by Whirlpool Corporation.
Late Friday (Jan. 24), the company submitted a revised work plan to the Arkansas Department of Environmental Quality that it said would meet the requirements of ADEQ's Remedial Action Decision Document (RADD) issued in late December 2013.
Whirlpool has spent much of the last year going back and forth with ADEQ on which measures would properly address a spill of trichloroethylene (TCE) at the facility, with Fort Smith residents watching from the sidelines. The company has admitted that the degreasing agent it used until the 1980s, which the Environmental Protection Agency has said is a carcinogen, leaked into the groundwater and is now in a plume that covers a large area at the facility and in the neighborhood to the north.
The company said the revised work plan submitted Friday was a revision of a July 2013 work plan it had submitted prior to the final RADD issuance last month.
The plan, outlined by Corporate Vice President of Communications and Public Affairs Jeff Noel, includes what he calls five key steps — pre-design, bench scale testing, pilot scale chemical oxidation injection treatments, design refinement, and expanded chemical oxidation injection treatments.
The pre-design phase was already initiated by Whirlpool in December and has been ongoing through January, according to the revised work plan document. The pre-design leads directly into the bench scale testing, Noel said.
"Based on results from the pre-design activities,a thorough bench scale screening of oxidants is completed," he wrote. "The bench scale testing will screen oxidants using actual soil and groundwater from the Whirlpool site generating data needed for the more rigorous onsite pilot scale testing."
The pilot scale testing will take place in a location known as "Area 1." According to an accompanying map included with the revised work plan, Area 1 is located directly on the north side of the now-shuttered Whirlpool facility between the parking lot and Ingersol Avenue. A location known as "Area 2" lies next to Ingersol's westbound lane. "Area 3" lies less than a half-block north of Area 2.
"The (pilot scale chemical oxidation injection) process allows for verification and potential improvement of oxidant performance and delivery methods specific to site conditions before moving to expanded design and implementation," Noel wrote.
The chemical oxidation injection will include injecting chemicals directly into the ground in order to neutralize the TCE chemicals already found in groundwater below the surface.
The design refinement phase will make final design recommendations for eventual chemical oxidation in all three locations, known as the expanded chemical oxidation injection treatments.
"Phase I of the expanded implementation is currently planned to include oxidant injections at the three locations using methods determined to be most effective and least disruptive to the community," Noel wrote. "Phase II implementation is expected to build on Phase I by further reducing any remaining COC (constituent of concern) concentrations in the three target areas thereby enhancing the effectiveness of the ongoing MNA (monitored natural attenuation)."
While the pre-design and bench scale testing have already begun, full implementation of phase I is not scheduled to take place until Spring 2016, with phase II beginning a year later, according to Noel's submitted report to ADEQ. When a previous six month monitoring period has ended, an evaluation will determine if additional chemical injections are needed.
Previous documents have indicated 2018 as a likely date for completion, though no mention of that date was made in the latest work plan, with Noel simply stating, "The soil cover will be installed after completion of all ISCO injections."
In addition to revising the company's work plan with ADEQ, Whirlpool indicated that it would install additional soil gas monitoring that "will provide additional lateral coverage over the off-site groundwater plume area." One of the planned locations is "an occupied residential building."
"The idea is to install additional soil gas monitoring points at locations that have higher potential for vapor intrusion to occur compared with other locations in the area," Noel wrote.
The company did again stress "that there is no unacceptable vapor intrusion risk from the Site," adding that the "objective of this soil gas monitoring component is to provide additional assurance that the off-site groundwater plume north of the Site does not present a concern for vapor intrusion into the indoor air of the buildings overlying the plume."
At both the residential location, as well as another off-site location, the monitoring points will be installed at two depths, he said.
"The first will be installed just above the groundwater surface to characterize the soil gas due to volatilization of the TCE from the groundwater. The second monitoring point will be installed at a depth approximately midway between the groundwater surface and the ground surface, or at least five feet bgs (below ground surface), to characterize the degree to which TCE in vapor from the groundwater is or is not migrating to the shallower depth."
ADEQ must still approve Whirlpool's latest work plan.