California Code, Health and Safety Code - HSC § 25292.4

(a) On and after November 1, 2000, an owner or operator of an underground storage tank system with a single-walled component that is located within 1,000 feet of a public drinking water well, as identified pursuant to the state GIS mapping database, shall implement a program of enhanced leak detection or monitoring, in accordance with the regulations adopted by the board pursuant to subdivision (c).

(b) The board shall notify the owner and operator of each underground storage tank system that is located within 1,000 feet of a public drinking water well, as identified pursuant to the state GIS mapping database, of the owner's and operator's responsibilities pursuant to this section. The board shall provide each local agency with a list of tank systems within the local agency's jurisdiction that are located within 1,000 feet of a public drinking water well, as identified pursuant to the state GIS mapping database.

(c) The board shall adopt regulations to implement the enhanced leak detection and monitoring program required by subdivision (a). Before adopting these regulations, the board shall consult with the petroleum industry, local governments, environmental groups, and other interested parties to assess the appropriate technology and procedures to implement the enhanced leak detection and monitoring program required by subdivision (a). In adopting these regulations, the board shall consider existing leak detection technology and external monitoring techniques or procedures for underground storage tanks.

(d) If the results of the enhanced leak detection test indicate that any component of the underground storage tank system is leaking liquid or vapor, the owner or operator shall take appropriate actions to correct the leakage, and the owner or operator shall retest the system using enhanced leak detection until the system is no longer leaking liquid or vapor.