The U.S. Chemical Safety Board (CSB) has urged the state of Virginia to regulate or authorize local jurisdictions to oversee the design, construction, maintenance, and inspection of large fertilizer storage tanks.

The suggestion was part of the board's final report into the November 2008 fertilizer tank collapse at Allied Terminals in Chesapeake, Virginia.

In the incident, a tank failed while releasing 2 million gallons of ammonium-nitrate fertilizer, seriously injuring two workers. The release flooded sections of a nearby residential neighborhood.

CSB found that the tank involved in the accident had undergone welding work; apparently, the welding did not conform to recommended industry practices.

Also, says CSB, Allied Terminals did not ensure that post-welding inspections were conducted before refilling the tank.

The Environmental Protection Agency (EPA) regulates the safety of petroleum storage tanks. But liquid fertilizer and other non-petroleum tanks are regulated by individual states.

In its report, CSB recommended that EPA revise a safety bulletin on liquid fertilizer tank hazards.