Cal. Education Code § 48661

(a) A community day school shall not be situated on the same site as an elementary, middle, junior high, comprehensive senior high, opportunity, or continuation school, except as follows: (1) When the governing board of a school district with 2,500 or fewer units of average daily attendance reported for the most recent second principal apportionment certifies by a two-thirds vote of its membership that satisfactory alternative facilities are not available for a community day school. (2) When the governing board of a school district that is organized as a district to serve kindergarten and grades 1 to 8, inclusive, but no higher grades, certifies by a two-thirds vote of its membership that satisfactory alternative facilities are not available for a community day school. (3) When the governing board of a school district that desires to operate a community day school to serve any of kindergarten and grades 1 to 6, inclusive, but no higher grades, certifies by a two-thirds vote of its membership that satisfactory alternative facilities are not available for a community day school. (b) A certification made pursuant to this section is valid for not more than one school year and may be renewed by a subsequent two-thirds vote of the governing board.