The early warning system sirens in the Diablo Canyon emergency planning zone are scheduled for low volume growl tests today and tomorrow.
Each siren in the zone will be tested individually for a few seconds; no action is required from the public during the tests.
The sirens can be used for any local emergency, such as a tsunami or dam failure.
The county office of emergency services says the sirens extend from Cayucos to the Nipomo mesa in the south along the coast.
