Corrective Action at a Hazardous Waste Unit
Troy Risk performed a RCRA Corrective Action at a closed hazardous waste landfill for a multinational landfill company. The work involved inspection and cleaning of two 85-foot leachate risers. A leachate riser is a stack of 4-foot diameter concrete pipe sections, which provide a passage to the bottom of the hazardous waste landfill. The riser provides access to pumps and electronic leachate level sensors located at the bottom of the landfill.
Replacement of the leachate pumps was impossible due to a tangle of pipes, pumps and wires in the riser. The replacement of the pumps was necessary to lower the elevation of leachate below methane well screens, which had become "watered in". The conditions for Troy Risk’s work at the bottom of the riser were the worst imaginable—85 feet below grade, in hot (over 140° F ), corrosive liquid hazardous leachate, which was bubbling with explosive methane gas.
Troy Risk used a large vac truck to purge the explosive atmosphere in the riser, and then used a subcontracted methane diver to enter the riser and clear a tangled debris of pipes, pumps and wires that prevented further use of the riser. A detailed video inspection was made of the riser assembly including each joint in the concrete pipe. Troy Risk assembled a report of the corrective action, including drawings of the riser assembly, and the inspection video. The report was submitted and approved by state regulators.