"Contractors put trucks on barges and hook the hoses up to skimmers, which do the actual skimming in the water," said Graham Kinchen, facility manager for Vacuum Truck Rentals in Geismar, La., near Shreveport. "They're mainly using the truck for the vacuum system and the tank capacity on it."
On the vehicles, engine-driven pumps pull air out of tanks to create the vacuum. "Bag houses" aboard the vehicles contain filters to capture residue from the drawn-out air. There are also clean-out traps and check valves to prevent blow-back.
Trailers are often pulled by PTO pump-equipped tractors, but Vacuum Truck Rentals' 130-barrel trailer is self-contained, with a Deutz diesel engine to drive the pump and bag houses, so any tractor can pull it (www.vactruckrental.com).
When tanks are full, the barges, pushed by tug boats, return to docks and the oil water is pumped to other tanker rigs waiting to haul it away. Semitrailers with capacities of 130 to 150 barrels, at 42 gallons per barrel in petroleum industry parlance, take the spoiled water inland to be injected into old wells, deep in the earth.
There's too little oil content to make refining economically feasible, Kinchen explained.
"At best you're skimming 50 percent water and 50 percent oil," he said. "A lot of times it's 80-20 water to oil. It depends a lot of times on how good the operator is."
Kinchen says he has 30 to 35 vehicles rented to contractors for cleanup duty. And he's heard that hundreds more are at staging sites along the Gulf Coast, brought in from around the country by BP, government agencies and their contractors.
One contractor has assembled 250 vacuum trucks near Gulfport, Miss. Slightly south of there is another staging area that can hold 800 trucks. They are all on standby.
Louisiana Tank of Lake Charles has 10 vacuum trucks dedicated to the Gulf cleanup, says supervisor Bobby Willwork. "We just got moved from Mobile, Alabama, to Panama City, Florida." Are his 10 trucks doing any actual cleanup work? "We've been on call for two months, but except for moving some flatbeds and that kind of thing, no."
More on tankers in the Gulf will appear in Heavy Duty Trucking's August issue.