The smell appeared after the seal on a tank containing about 1 million gallons of processed water and hydrogen sulfide, by-products of the refining process, ruptured around 7:50 a.m. The rupture happened along the top rim of the tank, where the seal meets the wall, somewhat like a can opener.
To lessen the smell, crews doused the tank with water throughout the day. Still, the smell made many people sick. "I don't want this to happen anymore. This is too much. It made me sick," Crockett resident Tricia Mayo said, sobbingly. "I thought something died in the house."
"We have a tank repair contractor here on-site developing a plan to patch that tank," Mark Hughes with ConocoPhillips told ABC7 News. "We expect to have the tank patched by tomorrow afternoon. We're also transferring all the product, that processed water, to another storage tank, so we're emptying that tank."
There was no shelter-in-place and no evacuation. Air monitors initially alerted ConocoPhillips of the problem, and then the company alerted air quality officials as well as Contra Costa County hazardous material officials. The company says the smell was well below unsafe levels, although it stunk horribly.
ConocoPhilips says a seal rupture like this has not happened before. The company says they do not know why or how it happened, but they plan to investigate.