Officials Lift Evacuation Orders for Some Near Damaged California Chemical Tank

Emergency officials lifted an evacuation order Monday for some residents living near a damaged tank containing a hazardous chemical in Southern California after temperatures inside the tank fell enough to eliminate the risk of a catastrophic explosion.

While there is no longer a risk of a major explosion at the GKN Aerospace Transparency Systems plant in Garden Grove, there is still a chance for a smaller blast or a fire, Orange County Fire Authority division chief Craig Covey said during a news conference.

An overnight evaluation of the tank containing 6,000 to 7,000 gallons of methyl methacrylate showed a reduction of pressure inside the tank thanks to a crack discovered Sunday.

About two-thirds, or roughly 34,000, of the evacuated residents can go home as a result, Covey said. "It’s not over yet. We still have work to do," Covey said. " The tank’s interior had cooled to 93 degrees Fahrenheit, Covey said Monday, down from 100 degrees a day earlier.

Environmental Monitoring Orange County Health Director Regina

Chinsio-Kwong said there was no contamination, no fumes and no vapors from the incident. "There was not a leak. So it should be, you should feel comfortable going home even if you’re across the street from that new zone line," she said. The South Coast Air Quality Management District will monitor the air for several months and the EPA will check the sewer and storm drains, Orange County Supervisor Janet Nguyen said.

Aerospace technical specialists and the Orange County Fire Authority removed external insulation material from the tank to help cool its contents, according to a GKN Aerospace statement released Monday. "We apologize for the ongoing disruption this incident is causing and our priority remains its safe resolution, so that residents can return to their homes as quickly as possible," the statement said.

GKN Aerospace is a British company that makes cockpit windows, canopies and windshields for military and commercial aircraft and employs about 16,000 people across 32 manufacturing sites in 12 countries. Disruptions at facilities producing specialized aircraft components can be difficult for the global aerospace industry to absorb because supply chains are highly concentrated and already strained, said Richard Aboulafia, managing director of the aerospace consulting firm AeroDynamic Advisory.