U.S. Chemical Safety Board (CSB) investigators found that welds performed on tanks were substandard and post-welding inspections were not conducted prior to filling at Allied Terminals in Chesapeake, Va., where an above-ground liquid fertilizer tank collapsed catastrophically last November. The collapse resulted in the release of 2 million gallons of liquid urea ammonia nitrate, seriously injuring two workers and spreading fertilizer on a nearby neighborhood and into the Elizabeth River (GM Nov. 17, 2008). In its final report issued May 27, CSB recommended that Virginia regulate, or authorize local jurisdictions to regulate, the design, construction, maintenance, and inspection of large fertilizer storage tanks located on the Elizabeth River. At least part of 200,000 gallons of spilled fertilizer that was unaccounted for reached the Elizabeth River, and possibly flowed into the Chesapeake Bay.
“By recommending regulation of similar storage tanks located on the Elizabeth River, we hope to protect not only communities and workers but also the vitality of the Chesapeake watershed,” William Wark, CSB member, commented in the report. CSB investigators found that the tank involved in the accident ?Çô referred to as Tank 201 ?Çô had undergone welding work. Contractors removed the vertical riveted seams and replaced them with welded plates, with the intent of strengthening the joints. Similar work was done to three other tanks at the facility. “The CSB’s investigation found that the welding performed on the tanks did not conform with recommended industry practices,” said Investigations Supervisor Robert Hall, P.E. “Additionally, the company did not ensure that post-welding inspections were conducted prior to refilling the tank to its maximum capacity.”
The report noted that the U.S. Environmental Protection Agency (EPA) regulates the safety of petroleum storage tanks, but liquid fertilizer and other non-petroleum tanks are regulated by individual states. Virginia is one of 33 states that do not currently have regulations for liquid fertilizer tanks, CSB noted. In addition to calling for state action to regulate storage tanks, the board urged EPA to revise and reissue a safety bulletin on liquid fertilizer tank hazards, and asked The Fertilizer Institute to urge member companies to require appropriate inspections of tanks used to store liquid fertilizer at terminal facilities.
TFI Vice President of Communications Kathy Mathers told Green Markets that the CSB team met with TFI during the investigation and then again a few weeks ago, after the investigation had been concluded, to inform TFI of the TFI-specific recommendation in the final report. She said the team was very pleased with the TFI tank guidelines, but was concerned that while TFI had issued the recommended guidelines for liquid fertilizer tanks in 2001, Aboveground Storage Tanks for Liquid Fertilizer ?Çô Recommended Inspection Guidelines, incorporating API 653 by reference, that Allied was unaware of the guidelines prior to the incident.
Mathers said CSB has advocated that TFI formally “recommend” to all of its members that the 2001 guidelines be followed, and in addition suggested that all contracts for UAN storage contain a recommendation that these guidelines be followed. She said TFI will be receiving a formal letter from CSB regarding the recommendations and that it has 60 days in which to advise CSB of the action TFI will take, at which time CSB will determine if TFI’s plans are satisfactory. She added that after the meetings with CSB, TFI is stepping up its efforts to ensure its members are aware of the guidelines’ value in evaluating tank safety.
In December 2008, CSB issued an urgent recommendation calling on Allied Terminals to take immediate action to reduce the risk of a catastrophic failure of three tanks located at its facility – one about 250 feet from the South Hill Neighborhood. CSB also recommended that Allied Terminals select an independent engineering firm to evaluate the specified tanks, and within 30 days provide a report prepared by the independent tank engineering firm to the City of Chesapeake. The independent report resulted in Allied Terminals significantly reducing the maximum liquid levels of the remaining tanks.
The CSB investigation identified 16 other tank failures at nine facilities in other states between 1995 and 2008. These 16 failures resulted in one death, four hospitalizations, one community evacuation, and two releases into waterways. CSB, an independent federal agency charged with investigating industrial chemical accidents, does not issue citations or fines, but does make safety recommendations to plants, industry organizations, labor groups, and federal regulatory agencies.