Costco Evacuated After Gas Leak

The Costco store on Monument Boulevard in Concord was evacuated and shut down after a chemical leak from a refrigerator late Sunday morning.

ConFire Battalion Chief Terry Stewart said emergency personnel were called in by firefighters who happened to be shopping at the store after employees pointed out a haze near the store's ceiling about 11:10 a.m.

The store was immediately evacuated.

The leaking gas was determined to be a dangerous refrigerant from the store's mechanical refrigeration system. The gas in question is an asphyxiant, meaning it sinks to the ground and displaces oxygen, and it is odorless, "so you could walk into a cloud of it and not know," said Contra Costa County Fire Inspector George Laing.

While the store's refrigeration rooms are equipped with sensors to detect such leaks, this leak from a pipe outside the refrigeration areas. Fortunately, the gas release was visible, Laing said.

The store was aired out and monitored until the gas dropped below hazardous levels, and a store repair technician was called to the scene to fix the refrigeration system.

As of 3:30 p.m., the store had still not been reopened, as county environmental health officials were checking for remaining signs of contamination.

"I was checking out when the cashier pointed to [the haze]," said Dan Desmond, 47, a Martinez resident. "People weren't running, but moving along quickly."

Earlier, an employee told Concord Patch the refrigerator had exploded, but that report turned out not to be true.

The store's parking lots were blocked off by shopping carts and customers were being turned away. A minor traffic jam was forming around the store and Concord Police arrived on scene to help block some of the entrances.

At least one customer was unhappy with the lack of information available.

"This is poor customer service that they don't post a sign with an ETA of when the store will be open again," said Renee, an Emeryville resident. "We shouldn't have to drive around. A simple sign would do."

Were you turned away or happened to be inside the store? Tell us in the comments.

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Bay City News contributed to this report.