California Code of Regulations
Title 19 - Public Safety
Division 1 - State Fire Marshal
Chapter 10 - Explosives
Subchapter 4 - Use and Handling of Explosives
Article 6 - General Explosives
Section 1568.7 - Protection of Facilities

Whenever blasting is being conducted in the vicinity of gas, electric, water, fire alarm, telephone, telegraph or steam facilities, and flammable liquid and any similar lines, the blaster shall notify the appropriate representatives of such facilities, at least 24 hours, in advance of blasting, specifying the location and intended time of such blasting. In an emergency this time limit may be waived by the "Chief" having jurisdiction.