Cal. Health & Safety Code § 6957

(a) A proposal to form a zone within a public agency may also be initiated by filing a petition with the board. Such a petition shall contain all the matters specified in subdivisions (a), (b), (c), and (d) of Section 6956. Such a petition shall be signed as provided in either of the following:
1. (1) By not less than 10 percent of the voters who reside within the territory proposed to be included within the zone.
2. (2) By not less than 10 percent of the number of owners of real property, including both land and improvements to land, within the territory proposed to be included within the zone who also own not less than 10 percent of the assessed value of the real property within such territory.
(b) Each signer of a petition shall add to his or her signature, the date of signing. If the signer is signing the petition as a voter, he or she shall add to his or her signature his or her place of residence, giving street and number, or a designation sufficient to enable the place of residence to be readily ascertained. If the signer is signing the petition as an owner of real property, he or she shall add to his or her signature a description of the real property owned by him or her sufficient to identify the real property.
(c) Following certification of the petition, the board shall set the time and place of the hearing on the question of the formation of the proposed zone.