(a) The board of directors shall consist of members as follows:

1. (1) The City Council of the City of Sacramento may appoint three members to the board.
2. (2) The Board of Supervisors for the County of Sacramento may appoint three members to the board.
3. (3) For as long as the City of Elk Grove is annexed into the district, the City of Elk Grove may appoint two members to the board.
4. (4) A member entity that is not identified in paragraph (1), (2), or (3) may appoint one member to the board.

(b) A city or county that is not annexed to the district may become a participating entity that may appoint at least one member to the board if the participating entity enters into an agreement with the district that provides for all of the following:

1. (1) The participating entity agrees to pay its proportionate share of the district’s cost to provide rail or other districtwide transit services.
2. (2) The district agrees to maintain a specified level of rail or other districtwide transit services.
3. (3) The district is not obligated to provide transit services to any particular location or along any particular route.