Martinez Refining Company

It's the first Wednesday of the month, so the Community Warning Sirens will be tested at 11am. It is only a test. The Community Warning System is operated by Contra Costa County Office of the Sheriff. You can register to receive Community Warning System alerts via text, email or phone message at https://cwsalerts.com/. The refinery runs tests to ensure sirens are operational. You may also hear sirens on Mondays between 11am-noon. That's when we test our internal alarms, and there's a chance they could be heard along the fence line.