Cal. Elections Code § 3025.5

(a) (1) A county that does not conduct an election pursuant to Section 4005 shall provide at least two vote by mail ballot drop-off locations within the jurisdiction where the election is held or at least one vote by mail ballot drop-off location for every 30,000 registered voters within the jurisdiction where the election is held, as determined on the 88th day before the day of the election, whichever results in more vote by mail ballot drop-off locations. (2) Notwithstanding paragraph (1), for a jurisdiction with fewer than 30,000 registered voters, at least one vote by mail ballot drop-off location shall be provided. The elections official shall make a reasonable effort to provide a vote by mail ballot drop-off location in the jurisdiction where the election is held. (b) A vote by mail ballot drop-off location provided for under this section consists of a secure, accessible, and locked ballot box located as near as possible to established public transportation routes and that is able to receive voted ballots. All vote by mail ballot drop-off locations shall be open at least during regular business hours beginning not less than 28 days before the day of the election, and on the day of the election. (c) At least one vote by mail ballot drop-off location shall be an exterior drop box that is available for a minimum of 12 hours per day. (d) For the purposes of this section, “vote by mail ballot drop-off location” has the same meaning as in Section 3025.