The board may, in its discretion and upon terms and
conditions set by the board, authorize an employer to participate in
the prefunding plan established by this article. The governing body
of a participating employer shall enter into a contract with the
board, setting forth the terms and conditions of that employer's
participation in the prefunding plan, including, but not limited to,
funding, expenditures, and actuarial, accounting, reporting, and
investment considerations.