Deconstructing Dredging Equipment For the Coal Ash Spill
Last Tuesday Tennessee approved the start of river dredging for the cleanup of the coal ash spill at TVA’s Kingston Fossil Plant about 40 miles west of Knoxville. TVA wants to remove the ash from the Emory River while not disturbing the native or original sediments and restore the Emory River navigation channel flow to an elevation of 710 feet.
Think of these as big floating vacuum cleaners with a huge rotating bristles. Each dredge has a capacity to pump up to 5,000 gallons per minute water with up to 20 % solids a distance of 6,000 feet. Basically, one dredging machine can move 3,000 cubic yards of material during 24 hours of operation.
The ‘bristles” are a 32″ diameter cutter head which will allow dredging to a specific depth. A GPS on board will allow the dredge to be placed with precision. Bathymetric surveys will be utilized on a monthly basis to verify progress of the ash removal.
These dredges are still small enough to be hauled easily to different locations.