Pollution Prevention and Bilge Water Recovery

At American Commercial Barge Line Co. (ACBL), protection of the marine environment is a top operating priority. As part of this commitment, every effort is made, using ingenuity and technology, in pollution prevention. An example of pollution prevention in practice at ACBL is the recovery of petroleum from bilge water (an oil/water mixture that collects in the bottom of a towboat), which is then blended into virgin fuel for use on ACBL towboats or resold as a cutter stock to a petroleum company. The source of petroleum in the bilge water is the diesel engines that power the towboat. The petroleum fraction is typically 30 percent. The bilge water is pumped from containment tanks on the boat into larger storage tanks at fueling or repairing facilities. ACBL currently operates a certificated barge that is dispatched to the various fueling and repair facilities to collect bilge water. This barge takes the mixture to American Commercial Liquid Terminal (ACLT) in Memphis, Tennessee. A process separates the oil from the water. The recovered oil is then blended with virgin diesel fuel for ACBL’s towboat fleet, used as ACLT boiler fuel, or sold as a cutter stock for ocean vessels. The separated water moves through a series of treatment tanks and an ultrafiltration system. The purified water is discharged into the Mississippi River according to a Tennessee National Pollutant Discharge Elimination System (NPDES) permit. In 1996 and 1997 combined, this process recovered 4.2 million L (1.1 million gal) of oil, which is material that was disposed of as waste in the past. ACBL is making a difference and embracing the principles of pollution prevention.