Authorities have announced that evacuation orders are being lifted for the remaining 16,000 individuals residing near a compromised chemical tank in California, following an earlier assessment indicating that the threat of a major explosion has significantly diminished.
The situation had forced 50,000 residents to evacuate from areas surrounding Garden Grove in Orange County last week. A crack that unexpectedly developed on the tank has relieved internal pressure, thus preventing a potential explosion and allowing most evacuees to return home during the U.S. Memorial Day weekend. The evacuation notice for 34,000 residents was rescinded on Monday evening.
However, evacuation orders remained in effect for about one-third of the evacuees due to concerns about the possibility of a minor explosion or a chemical spill. Many evacuees were staying in hotels, tents, emergency shelters at schools, or with relatives and friends.
The tank holds methyl methacrylate, a substance that is highly flammable. Health officials have reassured the public that there has been no release of contaminants or harmful fumes.
Authorities stated they will continue to monitor air quality for several months and will inspect sewer and storm drain systems.
Isabel Mendez reported experiencing a rash on her face, along with tingling lips and a sore throat while she was evacuating last week. After spending several costly nights in a hotel, she is currently staying with her mother in the Los Angeles area.
Mendez expressed uncertainty about returning home, voicing distrust in the officials’ assurances regarding safety. “Of course it is still dangerous,” she remarked.
An evacuee holds a small child at a shelter in the Elks Lodge in Garden Grove, California, on Tuesday. (Jae C. Hong/The Associated Press)
According to the federal Environmental Protection Agency (EPA), exposure to methyl methacrylate, which is used in plastic production, can lead to severe respiratory and neurological issues, along with skin, eye, and throat irritation.
The tank located at GKN Aerospace Transparency Systems, which manufactures cockpit windows, canopies, and windshields, contains between 22,700 and 26,500 liters of the chemical.
The company expressed, “We apologize for the ongoing disruption this incident is causing, and our priority remains its safe resolution,” emphasizing the need for residents to return home as quickly as possible.
Fire officials say a potential crack in a pressurized tank containing a toxic and highly flammable chemical at an aerospace manufacturing plant in California may help avert a cataclysmic explosion as tens of thousands of residents have been ordered to evacuate.
Cooling system valve failure
Teams at the manufacturing site worked diligently overnight to ensure that two adjacent tanks were neutralized and remained unaffected by the compromised tank, according to Orange County Fire Capt. Brian Yau.
Fire officials stated that the tank overheated due to a failure of a valve in the cooling system.
“That’s what kept it at 50 degrees,” or 10 C, noted Orange County Fire Authority Division Chief Craig Covey.
“Because of that malfunction, the tank began to heat up since it was not being chilled,” he explained during a news briefing on Monday evening.
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What is methyl methacrylate, the chemical that’s caused a state of emergency in southern California?
Firefighters sprayed water on the tank until the internal temperature was stabilized at 33.3 C, down from 37.7 C over the weekend, as reported by the fire department on Tuesday.
The facility’s sprinkler system continues to spray the tank, and the company reported that its technical teams and firefighters have removed insulation from the tank to facilitate cooling.
Fire officials also tested water from the storm drains and confirmed it was clean, said McGovern.
“There was no contamination,” stated Regina Chinsio-Kwong, Orange County’s health director, during a Monday press conference. “You should feel comfortable returning home even if you’re across the street from that new zone line.”
Two evacuees wait in their truck at a gas station within the evacuation zone in Stanton, California, on Monday. The chemical can potentially cause serious respiratory and neurological problems and irritation to the skin, eyes and throat, according to the U.S. Environmental Protection Agency. (Jae C. Hong/The Associated Press)
Environmental concerns
This incident unfolded in central Orange County, a densely populated region comprising several cities, including Garden Grove. With a population of 170,000, Garden Grove, along with nearby Westminster, houses Little Saigon, the largest Vietnamese community outside of Vietnam.
The area is also adjacent to Anaheim, which is home to Disneyland’s two theme parks, neither of which were subject to evacuation orders.
The South Coast Air Quality Management District plans to monitor air quality over the coming months, and the EPA will inspect sewer and storm drains for any spills, stated Orange County Supervisor Janet Nguyen.
As the tank’s temperature rose, the chemical transitioned from liquid to gas, increasing pressure and the risk of explosion, explained Andrew Whelton, a professor of engineering at Purdue University who has researched environmental contamination. He noted that some of the methyl methacrylate might have already solidified into a stable plastic akin to plexiglass, which lessens the hazard.
According to Whelton, “The tank was on the verge of a catastrophic explosion. The formation of a crack seems to have allowed pressure to escape,” but he cautioned that the tank needs to cool down to between 15.6 C and 21.1 C before it can be considered safe enough.
This California situation is reminiscent of a chemical spill that occurred in Charleston, W.Va., in 2014, caused by failing storage tanks. That incident left the capital city and surrounding areas without usable tap water for several days.
Businesses were temporarily closed, and hundreds of residents sought emergency medical treatment for symptoms ranging from nausea to skin rashes. This disaster led to new legislation mandating more inspections and registrations of above-ground storage tanks.
