The Coast Guard has issued a notice reminding the industry that the final deadline for the phase-out of single-hull oil tankers and barges in U.S. waters is Jan. 1. The phase-out of single hulls was mandated by the Oil Pollution Act of 1990 (OPA '90), the law that was passed after the Exxon Valdez accident in 1989. 

Read more at http://mariners.coastguard.dodlive.mil/2014/12/05/1252014-opa-90-single-hull-tank-vessel-phase-out-finalizing-on-january-1/