Proposition 1, which would raise the minimum wage from $9.19 to $15 an hour, was still leading Friday afternoon, but only by 55 votes.
Two thousand five hundred votes were tabulated for “Yes” and 2,445 votes were tabulated for “No” as of 4:30 p.m.
If the “Yes” vote maintains its lead, the new ordinance will take effect Jan. 1.
The new minimum wage will apply to the airlines, terminal concessions such as food services, off-site airport parking, rental cars, hotels and their restaurants at SeaTac airport. If workers don't get raises and paid sick leave provided by the initiative, they can take their employers to court.
Initiative backers said the city of Seattle has the responsibility to collect the records. It will have to determine its own method of auditing the estimated 70 businesses covered by the initiative, to make sure they're paying adequate wages.
The city hasn't started that process because the vote hasn't been certified and there's a pending court case on Prop 1.
SeaTac City Manager Todd Cutt said the court will be looking at "what of the basic tenets of the ordinance would apply, should apply, lawfully do apply and then how we're going to enforce that."