There shall be two alternate members of the Planning Board who shall be appointed by the Mayor, subject to approval by the Village Board, for terms of two years each, except that the terms of one of the alternate members initially appointed shall be one year. Thereafter, the term of each alternate member shall be two years from and after the expiration of the term of their predecessors in office. One alternate member shall be designated at the time of appointment as first alternate member. The other alternate member shall be designated at the time of appointment as second alternate member. The first alternate member shall sit as a member of the Planning Board to hear and determine in those matters before the Board whenever a regular member of the Board shall be disqualified from participating in such matter due to conflict of interest or unable to participate in hearing and determining such matter due to temporary inability to serve because of illness, absence or disability. In the event that more than one regular member of the Planning Board shall be disqualified or unable to participate in hearing and determining a particular matter for the reasons hereinabove set forth, the second alternate member shall sit as a member of the Board for the purpose of hearing and determining such matter. When so sitting to hear and determine a matter before the Board, each alternate member of the Board shall have the same powers and privileges as a regular member of the Board.