The Community Warning System Is a comprehensive, integrated system for alerting the public in Contra Costa County of imminent threats to life or health.  The CWS is available to any incident commander, 24/7, and may use alerting devices such as the Telephone Notification System (TENS), social media and messaging systems, 49 Safety Sirens, the Emergency Alert System (EAS) over broadcast radio and television, the California Emergency Digital Alert System (EDIS), and the CWS website –   www.cococws.us .