Chesapeake, Va.-The Chesapeake fire marshal who is heading up one of at least three investigations into the Nov. 12 collapse of a 2.5 million gallon liquid fertilizer tank has declined to confirm corrosion of tank welds as a possible cause. Fire department spokesman Steve Johnson told Green Markets, “The investigation is still in the preliminary or planning stage. Our focus is on assuring that required inspections and services have been properly completed on the facilities. Our task force will not be doing engineering evaluations, that is not their area of expertise.” Johnson did confirm that the fire marshal’s office is working with the federal Occupational Safety and Health Administration, and that Allied Terminals is doing its own investigation. Johnson termed as “assumptions” press reports that the corrosion from the fertilizer could have caused the failure, along with at least two other scenarios. “We will cooperate with OSHA and other private and public agencies that are stakeholders in this event,” Johnson insisted. “The press article you mention states assumptions. We have no conclusive evidence yet as to what caused the collapse.” Green Markets contacted Gary Boley, who heads his own company, Inter Spec LCC, in Norfolk, only two miles from the terminal. Although Boley has never inspected a tank there, he said there are lots of vertical and floor welds that could be attracted by nitrates combining with carbon to cause the corrosion. Boley, who was one of the first 20 inspectors certified by the American Petroleum Institute in the early 1990s and has inspected 500 fertilizer and several thousand oil and chemical tanks, suggested that the liquid line, which rises and falls with delivery of the product, could contribute to the weld problem. But liquid AN has not been found to have an effect on the walls of the tank, he added, and the age of the tank seems to be of little consequence. Another possibility cited by Boley is filling over certified levels, which puts the tank into “more severe service,” since fertilizer is 32 percent heavier than water and 70 to 75 percent heavier than gasoline. Boley also suspected that when the Allied tank was changed from riveted to welded two years ago, overheated welding rods could have been used, which would weaken the plates and leave them vulnerable to failure. Boley’s Inter Spec provides inspection and engineering services throughout the U.S. and internationally.
Transparency Across the Fertilizer Value-Chain