Posted on September 6, 2016
An excavator dipped its huge claw into the water of Pompton Lake on Wednesday, pulled up a load of black, mucky sediment, let it drain briefly, then swiveled and dumped the load onto a patch of asphalt on the shoreline.
Then it repeated the process.
It was the first day of a long anticipated three-year dredging operation to remove about 130,000 cubic yards of contaminated sediment from the lake bottom after years of studies, reports, delays and conflicts involving the federal government, local residents and DuPont, the company responsible for the pollution.
“The biggest thing that residents here tell us is they want to see action, and we’re finally at the point to do that, after a lot of hard work by many people,” said Pat Seppi, the project’s community involvement coordinator with the Environmental Protection Agency, which is overseeing the nearly $50 million cleanup.
The mercury, lead and other pollutants in the sediment and shoreline soil come from the former DuPont munitions facility in Pompton Lakes and Wanaque. The pollution was carried to the lake by Acid Brook, which runs through the former industrial site. The DuPont facility operated from 1902 to 1994, making blasting caps, metal wires and aluminum and copper ammunition shells the United States used in the two World Wars and other military conflicts.
The EPA wants the sediment removed because a toxic form of mercury can build up in fish, posing a health risk to humans who eat them. Exposure to mercury can damage nervous systems and harm the brain, heart, kidneys, lungs and immune system.
The 200-acre Pompton Lake, bordered by Pompton Lakes, Wayne and Oakland, is a backup source to replenish a key reservoir that supplies drinking water to towns in Bergen and Passaic counties. The lake is used by residents for skiing, boating and fishing, though it is so contaminated that fishermen are warned not to eat their catch.
The mechanical dredging that started Wednesday will create a shallow channel through the lake muck so a barge, loaded with dredging equipment and scows to carry dredged material, can float out to several small areas of the lake that total about 3 acres for cleanup there.
The channel was a new wrinkle in the project — officials had not anticipated one would be needed, said Perry Katz, the EPA’s project manager. The cleanup is the responsibility of Chemours, a DuPont spinoff company.
In the past two months, cleanup efforts have focused on removing contaminated soil along the lake shoreline. Nearly 500 truckloads of soil have been removed to a landfill in Pennsylvania, Katz said.
The decontaminated area, which borders a soccer field at Lakeside Middle School, has been covered with liners and paved with asphalt, and will be used as a temporary staging area for the larger dredging operation. The area also is bordered by a sheet pile wall driven into the sediment. In addition, a long line of orange booms have been installed on the lake surface at the perimeter of the work area, and turbidity curtains hang from them down into the water, to keep any disturbed sediment from floating into the cleaner areas of the lake.
As the excavator ate its way through the mucky lake bottom on Wednesday, two white swans floated nearby, seemingly unperturbed by the noise. Each time the excavator pulled the oozing muck from the lake bed, it deposited the material within a bin block on the asphalt — an area defined by temporary concrete blocks. A front loader then rolled in, scooped up the black sediment and moved it to another area.
Chemours’ contractor, Stevenson Environmental Services of Niagara Falls, N.Y., will now assess how much liquid the sediment contains and how much of a stabilizing agent needs to be added so the material can be trucked off-site without water leaking out onto roadways. The contaminated sediment will be carted to a landfill in Pennsylvania.
The water that drains from the sediment onto the asphalt will be pumped into machines that remove any contaminants. The water will then be returned to the lake.
Some residents have raised issues to the EPA about some aspects of the project. Jefferson LaSala, who lives a block from the work site and is on the board of a neighborhood advocacy group, said residents have been concerned that trucks leaving the work site filled with contaminated material were not using the routes through town dictated in an EPA-approved work plan.
Katz said Wednesday that Chemours has followed some of the trucks and found them taking the proper routes. Katz said he plans to trail some trucks unannounced as the dredging continues.
But he said trucks that had dropped clean fill at the site may have taken different routes back, since the designated route in the work plan was intended only for vehicles hauling the contaminated sediment.
Another concern, LaSala said, was that during a heavy rainstorm several weeks ago water rolled off the site into the street and down a storm drain. He said residents were worried that contaminated water from the site was getting back into the lake through the storm drain.
Katz said the storm drain empties into the area inside the work site bordered by the sheet pile wall and could not get to the rest of the lake.
While the project remains on schedule so far, LaSala said residents are still upset that a more thorough cleanup of the lake won’t occur. They wanted a more extensive cleanup that included areas where even lower levels of mercury were detected in the sediment.
The EPA had originally called for a larger area to be cleaned up, but renegotiated a smaller amount after DuPont had challenged the agency.
“It’s only a partial cleanup,” LaSala said. “It’s not enough.”
Work this year will end by mid-December.
Next year, the majority of dredging will occur on a 36-acre area of the lake near the mouth of Acid Brook. In the third year of the project, a cap of new fill will be spread on the dredged area to provide habitat for aquatic life, and new vegetation will be planted on the shoreline.
Source: 4-traders
