It's part of an investigation looking into possible violations at the plant that could have played a role in the hazmat incident at the GKN Aerospace facility last month.
"When there is a failure in the tanks, and it caused a massive evacuation, impacting 50,000 residents, we have an obligation to figure out whether any crimes were committed," said First Assistant U.S. Attorney Bill Essayli, who was on site as federal agents moved in Wednesday. "We want to know exactly what happened."
The search comes three weeks after a tank carrying 6,500 gallons of the highly toxic chemical methyl methacrylate (MMA) became unstable, causing the tank to heat up uncontrollably. For a few days, officials said the tank would either explode or spill out, and either outcome was inevitable. Eventually, the tank cracked, allowing the pressure to release and eliminating the threat of a BLEVE, which stands for Boiling Liquid Expanding Vapor Explosion.
The 15-page search warrant reveals investigators are looking for samples within tanks, records pertaining to the storage and handling of MMA, inspection and maintenance reports, audits, training materials and more.
Essayli says a team of top scientists and chemists have flown in from across the country for this search.
"We're not aware of any pending imminent hard that is presented to the community at this time from this plant, but we are going to find out... We'll get to the bottom of it."
In a statement, a GKN spokesperson said: "We are cooperating with authorities at our Garden Grove facility and will continue to do so."