California Code, Health and Safety Code - HSC § 111165

All testing of bottled water, bottled water sources, water distributed by water haulers, water from retail water facility, and water from vending machines shall be done by laboratories approved by the department, laboratories certified by the United States Environmental Protection Agency, laboratories certified by the primary enforcement authority in states that have been granted primacy by the United States Environmental Protection Agency, or laboratories certified (accredited) by a third-party organization acceptable to a primacy state.