Sirens and Refineries

The Community Warning System is a partnership between the Contra Costa County Office of the Sheriff, Contra Costa Hazardous Materials Program, Community Awareness Emergency Response group (CAER), and industrial facilities. The CWS’s 43 sirens are situated around industrial facilities from Richmond to Antioch. The sounding of the sirens is exclusively used along with the CWS’s many emergency alerting tools, to instruct residents to shelter in place and seek out emergency information during an event at an industrial facility. The CAER group, has provided education in 8 different languages to residents and businesses near the sirens and surrounding areas on what to do if sirens sound in their area. Besides sounding the sirens, CWS uses multiple tools including Wireless Emergency Alerts, broadcast media, Zonehaven, text messages, email, and automatic phone calls to every landline or cellular device (that has opted-in) in the county to communicate the potential impact to life or health along with the immediate protective action to be taken.
A siren is an alerting device that alerts you to a possible hazard in your area. The sound of a siren is meant to draw your attention away from your daily activities. You may work or live near a hazardous materials facility, dam, levee, or potential hazards. The best response to hearing a siren is to take protective action and SHELTER, SHUT, & LISTEN.
Shelter yourself, your family, and your pets (if possible) inside, away from the outside air.
Shut and lock all doors and windows. Turn off vents, air conditioners, and fans.
Listen to telephone notifications, radio, TV broadcasts, and other official information sources to learn important details about how to protect your health and how long to shelter.
Sirens are tested on the first Wednesday of every month at 11:00am. For the remaining Wednesdays, a more quiet and low “growl” test is performed at 11:00am.
Contra Costa County Health Services, Hazardous Materials Program, established an Incident Notification Policy that includes criteria for the various public notifications requirements during hazardous materials incidents.