The U.S. Department of Transportation should improve its data and regulatory analysis of tanker wetlines, according to a recent congressional report.
Wetlines are when flammable liquid remains in a loaded tanker’s external pipes, and a 50-gallon wetlines maximum is permitted under regulations. The DOT’s Pipeline and Hazardous Materials Safety Administration has pursued wetlines rulemaking after the National Transportation Safety Board recommended prohibiting transport of any hazardous materials liquids in this way in 1998.
The 2012 highway reappropriations act mandated the Government Accountability Office report on the matter before the agency could publish a final rule. That halted progress on a wetlines final rule the agency had sent to DOT Secretary Ray LaHood for review earlier that year.
That Sept. 11 report stated the agency should upgrade data by specifically requiring carriers to report wetline incidents and improve its information on the consequences of these incidents. Also, the PHMSA needs to address uncertainty in the assumptions and data underlying its regulatory cost-benefit analysis, the GAO added.
The National Tank Truck Carriers said it was pleased with the study and asked the agency, which had anticipated publishing a 2014 final rule, to withdraw the rulemaking. The DOT provided technical comments on the GAO audit, but did not indicate agreement or disagreement with its recommendations.
Industry and safety stakeholders have expressed concern over an existing technology to purge liquid from wetlines. They also have questioned other options to address wetline risks, but these alternatives have not been pursued.