Recommendation to regulate large fertiliser tanks

28 May 2009

In a final report issued into the November 2008 fertiliser tank collapse at Allied Terminals in Chesapeake, VA, the U.S. Chemical Safety Board (CSB) recommended that the Commonwealth of Virginia regulate or authorise local jurisdictions to regulate the design, construction, maintenance and inspection of large fertiliser storage tanks located on the Elizabeth River.

Recommendation to regulate large fertiliser tanks

On November 12, 2008, an above ground storage tank catastrophically failed releasing two million gallons of liquid urea ammonium nitrate (UAN) fertiliser and seriously injuring two workers. The release overtopped a containment dike and flooded sections of a nearby residential neighbourhood, requiring remediation of the soil. At least 200,000 gallons of spilled fertiliser could not be accounted for, and some reached the nearby Elizabeth River, which flows into the Chesapeake Bay.

CSB board member William Wark said: “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.”

CSB investigators found that the tank involved in the accident – referred to as Tank 201 – 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, PE. “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 regulates the safety of petroleum storage tanks, but liquid fertiliser and other non-petroleum tanks are regulated by individual states. Virginia is one of 33 states that do not currently have regulations for liquid fertiliser tanks, the CSB said.

In addition to calling for state action to regulate storage tanks, the Board urged the EPA to revise and reissue a safety bulletin on liquid fertiliser tank hazards and asked The Fertiliser Institute (TFI), a trade association, to urge member companies to require appropriate inspections of tanks used to store liquid fertiliser at terminal facilities.

In December 2008, the board 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 Neighbourhood. The 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 sixteen other tank failures at nine facilities in other states between 1995 and 2008. These sixteen failures resulted in one death, four hospitalisations, one community evacuation, and two releases into waterways.