The American Waterways Operators said the phaseout of single-hulled tank vessels was a public policy success that has produced significant environmental benefits. The final phaseout was Jan. 1, 2015. Per the Oil Pollution Act of 1990, all vessels that transport oil in bulk as cargo in the waters of the U.S. must now be outfitted with a full double hull that meets U.S. Coast Guard-specified standards. 

“The phaseout of single-hulled vessels is a milestone made possible by thoughtful bipartisan policymaking that enabled vessel owners to plan for and make multi-billion dollar investments in state-of-the-art, environmentally friendly tank barges and tankers to carry the nation’s vital energy cargoes,” said Thomas A. Allegretti, AWO’s president and CEO. “The transition to an all-double-hull fleet, combined with a comprehensive federal regulatory regime for oil spill prevention, response and liability and the adoption by vessel owners of safety management systems, vendor vetting programs and other safety measures, has produced dramatic, positive results for the American public. 

"Oil spills from tank barges have plummeted by 99.6 percent since enactment of OPA 90. This outstanding safety record is all the more relevant today given the nation’s energy renaissance and the vastly increased need for marine transportation of crude oil and petroleum products."