Every 2 years, the County Executive shall appoint two substitute members to the Board. The chair of the Board shall designate a substitute member to serve: when a regular member is absent or incapacitated for any reason; or if a vacancy is created. A substitute member shall serve until the regular member’s incapacity or absence ends or the vacancy is filled. While serving on the Board, a substitute member has all the powers and duties of a regular member. Subject to paragraph (2) of this subsection, a substitute member shall receive a per diem salary set by the Board for each day served. The salary of a substitute member may not exceed the daily salary of a regular member.