Georgia’s largest counties failed to prepare for heavy turnout in the state’s fiercely contested 2018 elections, resulting in wait times of up to four hours at the polls and delays in processing registration forms and mailing absentee ballots that ultimately kept some voters from casting ballots, according to a federal lawsuit.

The American Civil Liberties Union filed suit Monday in U.S. District Court in Atlanta on behalf of Georgia Shift, a group dedicated to increasing turnout among young voters. It says Fulton, DeKalb, Cobb and Gwinnett counties in metro Atlanta effectively disenfranchised voters by failing to provide enough polling sites, voting machines and staff.