Pollution
Humain
Environnement
Economique

A 7 560 m³ liquid fertilizer tank catastrophically failed around 3:20 p.m. The tank was being filled with liquid fertilizer to check for leaks prior to painting works. During the filling, a welder and his helper sealed leaking rivets on the tank. At a fill level about 7 cm below the calculated maximum liquid level, the tank split apart vertically, beginning at a defective weld located midway up the tank. Within seconds, the liquid fertilizer overtopped the secondary containment, partially flooding the site and adjacent neighbourhood. The collapsing tank wall injured the welder and his helper, who were working on the tank. Employees of a neighbouring business responded and extricated them. At least 756 m3 of the liquid fertilizer were not recovered; some polluted the southern branch of the Elizabeth River.

The tank dated back to 1929 and had been reinforced with welds in 2006. However, the welds on the plates that replaced the vertical riveted joints did not meet industry quality standards for tank fabrication. Furthermore, no post-welding inspection (spot radiography) had been performed before calculating the maximum liquid level for the tank. The operator also had no safety procedures or policies for work on or around tanks that were being filled for the first time following major modifications and directed contractors to seal leaking rivets while the tank was being filled to the calculated maximum liquid level for the first time. The US Chemical Safety Board (CSB) made recommendations for the safety of liquid fertilizers tanks (design, building and construction).