Seven out of Pennsylvania’s 67 counties will wait to count mail-in ballots until the day after the election, according to local officials, potentially delaying when media organizations will be able to project a winner in the state.

Pennsylvania allows for counties to begin processing mail-in ballots the morning of Election Day, but officials in Beaver, Cumberland, Franklin, Greene, Juniata, Mercer and Montour — all counties which voted for Donald Trump in 2016 — said that concerns over staffing and resources led them to delay when they will count mail ballots.

It is unclear what impact this could have on the timing of the results. The counties range in population size, but roughly a combined 150,000 voters in these areas have requested mail-in ballots according to state data.