The elective employer shall pay employer contributions for the LEOFF Plan I elected official. Such employer contributions will be calculated on the annual salary paid to the LEOFF I elected official for employment in the elective office. The elective employer will be directly billed by the department for employer contributions for a LEOFF I elected official. The elective employer shall pay employer contributions for LEOFF I elected officials in a timely manner as provided under chapter 415-114 WAC.