Agencies throughout San Luis Obispo County will collaborate Wednesday on a day-long drill involving a simulated emergency at the Diablo Canyon nuclear power plant.

While this kind of exercise is conducted regularly, Wednesday's effort involves simultaneously testing several communications systems, interagency coordination procedures and emergency response plans, according to county Emergency Services Director Ron Alsop.

Consequently, Alsop said, the public might hear of what sounds like an actual emergency, but isn’t.

They “can rest assured that it is only a drill,” Alsop wrote in a news release. “The emergency alert system will not be activated for the drill.”

The goal is to determine the effectiveness of existing emergency readiness procedures, he said.

Numerous state, county and local agencies are participating in the drill, which will be held in collaboration with Pacific Gas & Electric Co. The exercise will run from early morning to late afternoon.