Cal. Health and Safety Code § 25292.5

(a) On or before January 1, 2005, the owner or operator of an 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, and that is not otherwise subject to subdivision (j) of Section 25290.1, subdivision (i) of Section 25290.2, or Section 25292.4, shall test the system once using an enhanced leak detection test. The enhanced leak detection test shall meet the requirements of subsection (e) of Section 2640 of, and Section 2644.1 of, Title 23 of the California Code of Regulations, as those regulations read on January 1, 2003, except that the requirement in those regulations to repeat the test every 36 months shall not apply. (b) On or before June 1, 2003, 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 operators’ 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 within 1,000 feet of a public drinking water well, as identified pursuant to the state GIS mapping database. (c) Notwithstanding subdivision (a), 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.