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Remediation complete at Watson-Johnson Landfill Superfund site


Hailed as a model for effective cooperation among local, state and federal governments, the Watson-Johnson Landfill Superfund Site groundwater remediation project in Richland Township has been deemed completed.

The project now moves into the maintenance stage, which features ongoing groundwater monitoring toward assuring continued containment of a pollutant plume.

The announcement was made by Township Manager Paul Stepanoff during his monthly report at the Sept. 9 public board of supervisors meeting. The site is part of a 60-acre property off East Pumping Station Road.

“It was a pleasure to work with the federal government on this,” Stepanoff said. He noted that environmental specialists had “engineered a solution to keep the plume from spreading, with monitoring in place,” including some more monitoring that was added through a variance.

Stepanoff added that both the federal Environmental Protection Agency (EPA) and the state Department of Environmental Protection (DEP) had “thanked the township for providing meeting rooms, helping with truck traffic permitting, and providing material storage areas.”

During discussion, officials noted that at no time was the situation deemed a major threat to public health. Among eight private wells downstream of the plume, one was said to have switched to public water supply, while the others remained as they were, “by choice.”

In a 2016 public presentation in Quakertown, announcing the beginning of the cleanup, EPA’s remedial project manager said they had been actively monitoring the plume since the early 2000’s, noting that its “footprint hasn’t changed substantially, with some reduction in the concentration of volatile organic compounds (VOC’s),” and adding that “we feel very confident in our ability to continue to manage this plume.”

She added that there had been no indication of well water reaching contamination levels that exceeded EPA limits. EPA had maintained a continuing presence at the site, but a lapse in funding had delayed the start of the cleanup.

The remediation featured in-situ chemical oxidation, a process that was described during an earlier public EPA presentation as “widely used for over 15 years by EPA, with great success in all of its 10 regions.” Injection of sodium permanganate was to break up potentially hazardous chemicals, particularly tetrachloroethylene (TCE), into benign components that were to stay 60 to 80 feet below ground.

It was to be followed by 12-18 months of monitoring before a second injection, with a third injection possibly not needed to get the groundwater within EPA drinking water standards. A separate operation was conducted to cap the landfill, to contain contaminated soil.

Before the Sept. 9 supervisors’ meeting, Tom Marino, chairman of the township’s parks and recreation board, said that construction of the Upper Bucks Trail, which is to connect the county to a growing network of biking and walking trails throughout the region, was now in the bidding stage. Contracts might be awarded as soon as the Oct. 2 county commissioners meeting, with construction possibly beginning in October or November, weather permitting.