After the First Scoop : Hudson River Cleanup

This is a continuation from my previous blog post about one of the largest environmental cleanup projects ever attempted in the United States.

So, what exactly happens with the sediment?

The barges holding the sediment will be moved to a new waterfront barge unloading facility along the Champion Canal.

An excavator puts the sediment into a trommel which separates finer sediments from the debris, gravel and rocks. The remaining material is pumped into one of two hydrocyclones, where grit and sand is removed.

The slurry that's left is piped to an 80-foot diameter gravity thickener tank where polymer is added to clump larger particles together. The thickened slurry is then pumped from the bottom of the tank to one of 12 filter presses housed inside the dewatering building.

Filter plates inside the presses basically squeeze water from the slurry to form filter cake. Water removed during processing is filtered and discharged into the Champlain Canal.

The filter cake is loaded on to an 81-car train for disposal to a toxic waste facility in Andrews, Texas. GE has purchased an astonishing 450 new rail cars for this project. When this project is at full throttle and processing 500 cubic yards of sediment every day, the train will be leaving every 2.5 days.

The entire project will remove a staggering 1.8 million cubic yards of sediment.