In 2008, an aboveground storage tank catastrophically failed at Allied Terminals, Chesapeake, Va., releasing two million gallons of liquid urea ammonium nitrate (UAN) fertilizer and seriously injuring two workers.

Recommendations for state or local jurisdictions to regulate the design, construction, maintenance and inspection of large fertilizer storage tanks -- in the Commonwealth of Virginia as well as the 32 other states that do not currently have regulations for liquid fertilizer tanks -- were part of a final report on the Allied Terminals tank collapse issued by the U.S. Chemical Safety Board.

The Washington, D.C.-based federal agency also urged the EPA to revise and reissue a safety bulletin on liquid fertilizer tank hazards, and asked The Fertilizer Institute (TFI), a trade association, to urge member companies to require appropriate inspections of tanks used to store liquid fertilizer at terminal facilities. The U.S. Environmental Protection Agency regulates the safety of petroleum storage tanks, but liquid fertilizer and other non-petroleum tanks are regulated by individual states, according to the report.

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

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 horizontal 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 Robert Hall, a supervisory investigator at the CSB. "Additionally, the company did not ensure that post-welding inspections were conducted prior to refilling the tank to its maximum capacity."