A board employee said representatives of both candidates, and , are expected to turn out for the review of the votes cast in last week's election.
Spencer, a doctor at , led Black, a member of the Huntington school board, by 179 votes on an unofficial count when the polls closed.
It is not known whether the absentee tally will be completed by the end of the day Wednesday.
Absentee ballots had to be postmarked by last week but the law allows military ballots more time to arrive. The day after the election, the absentee ballot count stood at 502.
Spencer and Black were competing to fill the seat being vacated by Majority Leader Jon Cooper, who is term limited.
The intense 18th District race drew a higher number and percentage of voters than other legislative races in Huntington, with 28.71 percent turnout and 15,591 votes cast last week. By comparison, the 17th District race between victorious incumbent Lou D'Amaro and challenger Dennis Garetano, drew a 23.80 turnout, with 11,566 casting ballots, and the 16th, between the winning incumbent Steve Stern and challenger Deborah Poulos, had a 24.65 percent turnout, with 13,071 voting last week.