Toxic leak in Orange County: Tens of millions of liters of water sprayed to cool the area.

California state officials say they have ruled out a "worst-case scenario" in the chemical incident at the aerospace facility in Garden Grove, Orange County.

Emergency response teams began dealing with the hazardous materials incident on May 21st. The cleanup operation continued into Saturday, when the state governor declared a state of emergency. - Photo: Allen J. Schaben/Los Angeles Times

According to CBS News, officials in Orange County, California, announced on May 25 that they had reduced the evacuation zone around the chemical leak site in Garden Grove by 65%, allowing tens of thousands of residents to return home after five days of unrest.

According to authorities, the new evacuation zone covers an area of ​​approximately 16,000 residents, a sharp reduction from the initial size of around 40,000 people, following days of responding to the risk of fire and explosion from a cracked chemical tank at the GKN Aerospace plant.

Orange County Fire Authority Acting Director TJ McGovern said that responders have brought the most serious threat under control.

"We are pleased to announce that the catastrophic and worst-case scenario has been contained and eliminated," McGovern said, but stressed that the remediation work is not yet complete.

Officials said the main risk stemmed from a cracked methyl methacrylate storage tank, with two possibilities being considered: leakage or explosion.

To prevent the incident from escalating, firefighters continuously operated a high-capacity water spraying system to cool the tank.

According to field commander Craig Covey, the amount of water used reached tens of millions of liters. A single ground-based sprinkler system discharged more than 4,700 liters of water per minute to keep the tank temperature at a safe level.

The temperature inside the tank is believed to have dropped from around 100 degrees Celsius on May 23rd to approximately 93 degrees Celsius by the evening of May 25th (US time).

Under normal conditions, the temperature of the tank is only around 50 degrees Celsius when the cooling system is operating.

Nevertheless, Nick Freeman, head of OCFA's hazardous materials division, said rescue teams are continuing to monitor cooling trends and consult with chemistry experts to ensure the situation is moving in the right direction.

According to field commander Covey, over the past 24 hours authorities have been monitoring temperatures, removing insulation to improve cooling efficiency, and testing the pressure relief system. Authorities believe that most of the chemicals in the tank have solidified.

Dr. Regina Chinsio-Kwong of the Orange County Health Department said people "can safely return home," including those living near the new evacuation zone boundaries.

Authorities also said that the water used to cool the tanks and the air quality around the area are being monitored continuously.

According to the U.S. Environmental Protection Agency (EPA), the air quality monitoring system operates 24/7, but has not recorded any instances of levels exceeding safe limits.

Nevertheless, officials continue to urge residents to comply with the evacuation orders that remain in effect for areas where the alert has not yet been lifted.

Why is this incident dangerous?

According to the Los Angeles Times , the tank that malfunctioned in Orange County contained approximately 26,500 liters of liquid methyl methacrylate (MMA) – a chemical used to produce a clear, lightweight, and durable plastic that can replace glass in some products.

Although the finished plastic is non-toxic, the original liquid MMA is highly toxic. If released into the air, it can harm humans at high concentrations or with prolonged exposure.

Even short-term inhalation of MMA fumes can cause severe irritation to the lungs and nose, leading to nausea and dizziness. High-concentration exposures can result in severe respiratory failure, requiring hospitalization.

Besides its toxicity, MMA also poses a potential risk of chemical reactions that could cause fires or explosions if the storage tank loses control of temperature and pressure.

PUBLIC

Source: https://tuoitre.vn/ro-ri-chat-doc-o-quan-cam-phun-ca-chuc-trieu-lit-nuoc-de-lam-mat-20260526120510957.htm