Hudson River PCB dredging operation employs 95 barges

The following is the text of a press release issued by General Electric Co.:
(GLENS FALLS, N.Y.) — After taking a break from work over the holiday weekend, GE’s Hudson River dredging crews are back out in the river using eleven dredges, with five concentrating their efforts in the western channel of Rogers Island.

More than 36,000 cubic yards of sediment have been dredged from the Upper Hudson River through June 27 as GE and its contractors continue ramping up the project toward peak production.

High water flow continues to cause intermittent work stoppages. The high water flow comes both from recent heavy rain and from the releases from four hydroelectric dams and the Sacandaga Reservoir upstream. High river flows pose a risk of higher PCB resuspension and a potential safety hazard for dredging crews.

Even so, more dredging is being performed each week. In fact, since dredging began in May, 95 barges have been pushed by tugs to the Processing, Treatment and Transportation Facility north of Lock 7 on the Champlain Canal and unloaded.

Dredging has also begun in the eastern channel of Griffin Island, about halfway between Rogers Island and the Thompson Island Dam. This area is the farthest south dredging crews will be working this year.

This first year, or first phase, of the dredging project is a full-scale test to determine whether the best available dredging technology can achieve the engineering performance standards established by EPA in the natural conditions that we encounter in the Upper Hudson River.

A number of tasks have been completed to allow the pace of work to continue increasing, including:

Dredging to deepen the Champlain Canal, to allow barges loaded with sediment to travel through Lock 7 and under three bridges to GE’s Processing, Treatment and Transportation Facility just south of Lock 8; Building a water flow control structure in the eastern channel of Rogers Island (north of the Fort Edward Yacht Basin) to slow the speed of the river and lower the risk of PCB resuspension; Navigational dredging between Moreau and Rogers Island to deepen the river channel near where the clean fill will be loaded onto barges to refill dredged areas; Evaluating the remains of a sunken 1820s-era wooden sailboat. GE’s nautical archeologists have photographed, videotaped and drawn the layout of remnants of the sailboat to create a complete historical record. The wreckage was removed. A report is being prepared for EPA. All of the dredged sediments and debris managed at the Processing Facility is being transported by rail to a federally permitted waste disposal facility in Andrews, Texas.

GE has assembled a world-class team of dredging experts and environmental engineers to conduct the project: Cashman Dredging & Marine Contracting Co. LLC, based in Quincy, MA, is performing the in-river dredging work; The Shaw Group, Inc., of Baton Rouge, LA, is operating the unloading wharf and processing facilities; Penguin Logistics LLC (formerly MHF Logistical Solutions, Inc.) of Cranberry Township, PA, is operating the rail yard; AnchorQEA of Glens Falls is performing river monitoring to ensure compliance with the PCB resuspension performance standard required by EPA; ARCADIS of Albany is performing the Quality of Life standards monitoring to ensure compliance with the strict EPA requirements, and AECOM, based in Westford, MA, will perform habitat reconstruction work in the river after dredging.

These firms have been assisted by more than 190 Capital Region companies as subcontractors, vendors and suppliers. At peak operations, more than 500 people will be working on the dredging project. All of the work is paid for and coordinated by GE and approved and overseen by EPA.

The sheer size of the project makes it one of the largest environmental clean-up projects ever undertaken in the United States. To get the work done, GE has mobilized an enormous armada of equipment, including 11 dredges, 17 tugboats, 20 barges, and more than 400 rail cars, as well as skiffs, cranes and other machinery. At peak dredging toward the end of July and August, as many as 80 to 90 vessels are expected to be in the river each day. On the dredges, operators are guiding massive environmental clamshell buckets equipped with GPS to capture the 400,000 tons of sediment — over 94 acres — targeted by EPA for removal in the first year of the project.

The dredging is being performed with environmental clamshell buckets that were approved by EPA and are operating as designed. The dredges are encountering a large volume of logs, sticks and wood shavings, remnants of the legendary Adirondack log drives, in sediments around Rogers Island. Logs and wood shavings often become lodged in the jaws of the buckets, preventing them from closing completely. This allows water to escape.

Any sediment that may drop out of the bucket is removed in subsequent passes of the dredge. Moreover, PCB levels during all dredging operations are closely and continuously monitored to ensure compliance with EPA’s resuspension standard.

Once the barges arrive and are unloaded at the Processing Facility, sediments pass through specialized equipment to remove remaining sand, sticks, silt and rocks. Water is added to move the material through piping to 12 specially manufactured filter presses housed inside a sediment dewatering building, which squeeze the sediment to remove the water. That water is pumped to an on-site water treatment plant.

As water flows allow, dredging operations are being conducted 24 hours a day, six days a week (Sundays are reserved for contingencies and maintenance) and sediment processing and water treatment take place around the clock, seven days a week.

By Professional Mariner Staff