Worst-case scenario averted at California chemical leak in Orange County, officials say; evacuations lift as work persists

Orange County officials said they would assess on Tuesday the results of another overnight operation at a California aerospace facility, where a cracked chemical tank remains in danger of causing a small explosion or leaking toxic fumes.

The situation, dubbed the Western Incident, still had about 16,000 residents evacuated from their homes in the immediate area of GKN Aerospace in Garden Grove. That number is down from the approximate 50,000 who were evacuated over the weekend.

No new updates were issued on Tuesday morning as of 7 a.m.

Orange County Fire Authority Interim Chief TJ McGovern said in a brief on Monday that the threat of a BLEVE, or Boiling Liquid Expanding Vapor Explosion, was off the table after being deemed the possible worst-case scenario in the early stages of the incident. The success of an operation performed late Sunday night and into Monday morning led to the decision to allow tens of thousands to return to their homes for the first time in days.

"Throughout the day today, I'm happy to report the most catastrophic and worst-case scenario was mitigated and resolved," McGovern said.

"I was handed an incident that had two options: a spill or an explosion," OCFA Division Chief and Incident Commander Craig Covey said. "As the chief said, it was unacceptable. … We found a plan and we [implemented] it. That took time."

Officials on Monday night continued to stress that the situation was still potentially dangerous, hence the remaining evacuations. The overnight operation starting Monday night had crews working to mitigate potential for a smaller explosion or spill of the methyl methacrylate stored inside the cracked tank. 

Orange County officials said Monday that firefighters used a "deluge sprinkler system" to continuously douse a failing chemical tank at GKN Aerospace, helping to keep the temperature of the tank cool and preventing the potential of a fire. 

"So, you've got a deluge system with a full throttle on it, and then we have that ground monitor ... that's flowing 1,250 gallons a minute," OCFA Division Chief Craig Covey said. "We're talking millions and millions of gallons [of water]."

The operation that started on Sunday night confirmed the existence of a crack on the chemical tank, which was alleviating the pressure inside, calming fears of a massive explosion.

Garden Grove Police Department Chief Amir El-Farra announced that the new zone would include homes and businesses for approximately 16,000 residents in an area bounded by Orangewood Avenue to the north, Dale Street to the east, Knott Street to the west and Garden Grove Boulevard to the south.

Orange County Health Care Agency Dr. Regina Chinsio-Kwong assured those returning home that they "can feel safe."

"There was no contamination," she said. "You should feel comfortable going home, even if you're across the street from that new zone line."

Officials on Monday stressed that residents do not have to wash exteriors of their homes, outdoor furniture or walkways. 

A total of four local school districts, the Garden Grove Unified School District, Magnolia School District, Savanna School District and Westminster School District, have impacted school schedules for the week. Garden Grove has transitioned to full distance learning, while specific schools at the other districts are impacted. They can be found here.

President Trump and federal action

California Gov. Gavin Newsom announced Monday that President Trump had approved the state's request for a federal emergency declaration in Orange County.

The approval will allow the Federal Emergency Management Agency, or FEMA, to "direct federal assistance with personnel, equipment, and other specialized resources to support life-saving response," according to Newsom's office.

"California didn't wait for this situation to escalate — we moved early, aggressively, and in close partnership with local responders to protect lives and support impacted communities," Newsom said in a statement. "We are grateful for the federal government approving our request and helping strengthen the resources already on the ground to help this community recover safely."

According to FEMA, a Presidential Emergency Declaration differs from a Presidential Major Disaster Declaration in that it provides preemptive and protective action, while the latter provides assistance after a disaster causes significant damage.

When did the Garden Grove chemical leak start?

Crews arrived Thursday afternoon at the GKN Aerospace facility in the 12000 block of Western Avenue in Garden Grove after receiving a hazardous materials call just before 3:40 p.m. that day, according to OCFA. 

The chemical in the industrial tank initially stayed at the same temperature, officials said. However, about four hours after firefighters arrived, the temperature rose, causing a relief valve and sprinkler system to activate near the tank.  Firefighters said the sprinkler safety system is designed to cool off the tank if it starts leaking. 

The OCFA said crews initially made progress toward removing the chemical product but determined Friday morning that the "tank that is in the biggest crisis is in fact unable to be secured and mitigated."

No injuries have been reported.