7,000 gallons of disinfectant discharged at Vallejo water treatment plant

VALLEJO —  Seven-thousand gallons of the disinfectant sodium hypochlorite were accidentally discharged at the Fleming Hill Water Treatment Plant in Vallejo on Monday morning, causing an emergency response and hazardous materials cleanup, according to the city of Vallejo and the Solano County Environmental Health Division. 

According to a city press release, the discharge came from a secondary containment tank during maintenance activities involving the facility’s chemical storage system. Sodium hypochlorite, an ingredient in household bleach, is routinely used in the drinking water treatment process. 

As a result of the discharge, water department personnel immediately initiated emergency response, isolation, mitigation, and repair procedures. The incident was fully stabilized and cleanup was completed by 7:30 p.m., according to the press release. 

The city said that the quality of Vallejo’s drinking water was not impacted and there was no interruption to customer water service. The plant remained fully operational during the incident. 

“We are grateful for the rapid and professional response of our Water Department staff and emergency response partners,” city water director Beth Schoenberger said in a statement. “Their actions ensured the incident remained fully contained and did not impact public health, the environment, or our customers' water service.”

Chris Ambrose, a supervising hazardous materials specialist with the county, said that the county also sent out a health inspector as a result of the discharge.

Four workers were exposed during the discharge, according to Ambrose, but as of the inspector’s afternoon visit that day, there had been no hospitalizations. 

Ambrose said the release was deemed a medium risk to public health and the environment. But he added that the risk to the environment can really be viewed as low because the spill was localized to the secondary containment, which is built to contain such releases, and it stayed on the property.

“For many sites like this one, it’s very rare, if none at all, for a spill of this quantity,” Ambrose said. 

The city said that the Vallejo Water Department is conducting a thorough internal review of the incident and is evaluating the infrastructure to strengthen system reliability and improve safety protocols.