Cal. Health and Safety Code - HSC § 40300. Section 40300.
(a)
The boards of supervisors of two or more counties within an air basin may hold a public hearing to determine whether the counties under their jurisdiction should become part of a regional district.
(b)
Such boards of supervisors shall hold a public hearing to resolve such a question, if a petition is submitted to each such board of supervisors. A petition submitted to a board of supervisors shall be signed by not less than 10 percent of the qualified electors of the county under its jurisdiction.
