California Code, Water Code - WAT § 13178

(a) The state board, in conjunction with the State Department of Public Health and a panel of experts established by the state board, shall develop source investigation protocols for use in conducting source investigations of storm drains that produce exceedences of bacteriological standards established pursuant to subdivision (c) of Section 115880 of the Health and Safety Code.  The protocols shall be based upon the experiences drawn from previous source investigations performed by the state board, regional boards, or other agencies, and other available data.  The protocols shall include methods for identifying the location and biological origins of sources of bacteriological contamination, and, at a minimum, shall require source investigations if bacteriological standards are exceeded in any three weeks of a four-week period, or, for areas where testing is done more than once a week, 75 percent of testing days that produce an exceedence of those standards.

(b) The development of source investigation protocols pursuant to subdivision (a) is not subject to Chapter 3.5 (commencing with Section 11340) of Part 1 of Division 3 of Title 2 of the Government Code.