PG&E and county emergency services managers will conduct growl tests today and Wednesday on the 131 early-warning system sirens surrounding Diablo Canyon nuclear power plant.
The tests last only a couple of seconds, and the sirens do not reach their full volume. No action is required of the public.
The sirens are spread throughout the county from Cayucos in the north to the Nipomo Mesa in the south and as far inland as San Luis Obispo. The sirens are a required component of the nuclear power plant but can be used for any local emergency.