“Telltale signs” of microbial activity were found by investigators in a storage tank that exploded earlier this year, killing a contract worker and severely injuring another. The July 28 incident at the the Omega Protein facility in Moss Point, Mississippi involved hot work being done on or near a tank containing eight inches of a slurry of water and fish matter known as “stickwater,” which was thought to be nonhazardous.
The explosion blew the lid off the 30-foot-high tank. CSB investigators commissioned laboratory testing of the stickwater and found telltale signs of microbial activity in the samples, such as the presence of volatile fatty acids in the liquid samples and offgassing of flammable methane and hydrogen sulfide.