Emergency sirens were installed when the plant initially went operational. Federal law requires an early warning system that radiates out 10 miles from any nuclear facility, but the county siren coverage goes farther, extending from Cayucos in the north down to upper Nipomo to the south. All businesses are required to have a siren information sticker in their business generally located within the restrooms. Schools, government offices, and any other public building will have a PAZ card (Protective Action Zone). These cards show the 12 zones of evacuation with zone one being the plant itself. The cards also show the direction of evacuation on the highways.