Yellow lines trace area bordering part of Riverside Park where dredging is planned.
By Ron Leir
LYNDHURST –
Despite a technical setback, the U.S. Environmental Protection Agency (EPA) remains confident it can still proceed, as scheduled, with the removal of contaminants from mudflats along the Passaic River in Lyndhurst by late spring or early summer 2013.
Stephanie Vaughn, EPA project manager for a study on how best to clean up the river’s lower 17 miles, from the Dundee Dam to Newark Bay, confirmed published reports that the federal agency didn’t get the results it was hoping for in the application of “sediment washing” methodology on portions of the mudflats.
“Sediment washing would’ve been interesting had it worked,” Vaughn said, “but it looks like that won’t happen.”
Under the experimental process developed by BioGenesis, a Virginia-based firm, dredged materials from the Lyndhurst mudflats were taken to a treatment facility for chemical processing and bombarding by high-pressure water jets designed to separate out toxins such as cancer-causing dioxin and PCBs.
Vaughn said that the benchmark tests didn’t have the desired results and, unfortunately, “showed the process not to be effective” in these circumstances.
“We were hoping to see reductions of concentrations greater than 50%,” Vaughn said. Had that been the case, then the pollutants could then have been blended with another material for productive reuse, she said. However, test results indicated reductions “on the order of 10 to 20% ,” she said. Given those less than satisfactory results, “It just didn’t make sense to continue to try to adjust the process,” Vaughn said. The treatment process was “always an optional part of the entire (toxin) removal action for the river,” she said.
At this point, Vaughn said, the EPA plans to “go forward” with a plan to dredge 20,000 cubic yards of contaminated mud, to a depth of two feet, from a three-quarter-mile stretch of the river (about 5.5 to six acres), from where the river bends – adjacent to the northern part of Riverside Park – north to an area across from the Third River, all in Lyndhurst, Vaughn said.
“We are finalizing the design for how it will be removed from the area,” she said.
At this point, Vaughn said, “we will likely bring it by barge to another facility in the Newark Bay region for stabilization,” meaning that a material like cement would be mixed with it to dry it, and then the resulting product would be shipped – “most likely by rail or a combination of truck and rail – to a landfill, probably “out west – not in New Jersey,” she said.
Dredging will be done only on the eastern half of the river, not past the central line of the channel, said Vaughn. The project will start by “the end of May or early June,” but the work schedule remains uncertain.
“Do we run 24 hours a day, seven days a week? Or, maybe we limit the work to 12 a day, six days a week, for example, to impact the community less,” Vaughn said.
In any case, the entire removal effort should take “no more than eight weeks,” she estimated.
But Lyndhurst Commissioner (and former mayor) Richard DiLascio said he and his colleagues want assurances from EPA “that the material being dredged doesn’t touch our shore or travel through our roads.”
Aside from that, however, DiLascio said his “bigger concern is containment of contamination while they’re doing this work. We don’t want the contaminants flowing back into the township through our sewers. Here in Lyndhurst, we don’t have backflow preventers that would stop the river water from coming back through our pipes. And we have more than 60 river outfalls in the township.”
DiLascio said Lyndhurst has asked EPA to consider placing backflow preventers from the DeJessa (Kingsland Ave.) Bridge down to the railroad bridge near Lake Ave. to cover the furthest upstream and downstream points in the township but so far there’s been no response, he said.
Lyndhurst is still waiting to meet with EPA to learn more about its dredging design plan. “When we met with them last on Aug. 23, plans were 30% completed,” DiLascio said. “Apparently sedimentation washing works on coarser material than what we have in river, which is fine silt.”
Once the dredging is done, a cap of some sort will be applied, and Vaughn said that EPA experts are still puzzling over the cap’s design. As of now, the thinking goes that the bottommost layer should be carbon or another chemical element to trap any remaining contaminants; topped by a “geotextile liner” with sand in the middle; and an “armoring” layer of very fine gravel, resistant to erosion, on the surface.
While the Lyndhurst project will be under the EPA’s supervision, Vaughn said the “cooperating parties group,” comprised of companies or successor companies that have accepted fiscal responsibility for cleaning the river of pollutants, will bid out the job and hire contractors.
If, during the course of the work, additional areas of mudflats in proximity to the target area are found to be in need of cleanup “on an expedited basis,” EPA may “do those as well” as part of the Lyndhurst project, Vaughn said.
While the project is being completed, EPA will continue to work on a remedial investigation feasibility study that will explore options for cleaning up the Lower Passaic’s entire 17-mile stretch, along with a “focused feasibility study and cleanup plan” for an eight-mile stretch, from Belleville south to Newark Bay. That report is due March 2013, Vaughn said.
