If the department determines that a public water system is subject to potential contamination, the department may, by order, require the public water system to conduct a periodic water analysis in accordance with conditions specified by the department. The water analysis shall be reported on a quarterly basis, unless the department finds that reasonable action requires either more or less frequent analysis.
Source:
Section 116400, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=HSC§ionNum=116400..