More than 200 people in Oregon’s third largest county have begun hand counting thousands of ballots after a voting machine issue arose in the wake of the state’s primary elections earlier this week. The machines were unable to read up to 60,000 ballots that had blurry barcodes on them.

“The fact that they were behind in issuing results is no surprise. They have known about the blurred barcodes for weeks,” Clackamas County Board of Commissioners Chair Tootie Smith said Wednesday, referencing the county’s election department. “They must take the steps necessary to correct this problem they knew about weeks ago. Hand processing of their ballots is slow and tedious work that has to be done accurately and in this case briskly.”

To hand count the affected ballots, elections workers must pull the faulty ballots from batches of 125, transfer the voter’s intent to a fresh ballot, then double-check their entries. The process could draw the primary election out until June 13, when Oregon certifies its vote. The workers operate in pairs, one Democrat and one Republican, in two shifts of 11 hours a day.

“Facility space at elections is being expanded to accommodate the increased staff,” Smith said. “I have been and I will continue to be on site regularly to observe the process as any member of the public is allowed to do so. And I invite anybody down to view the process.”

The most notable result put on pause due to the voting machine issue is the Democratic Primary for Oregon’s 5th Congressional District.

Seven-term Rep. Kurt Schrader (D-OR), a moderate, was trailing in the vote behind progressive challenger Jamie McLeod-Skinner.

“We’re eagerly awaiting the final results of really all county offices. As you mentioned, most of the uncounted votes are in Clackamas County,” McLeod-Skinner said Thursday. “We expect all county offices to uphold the integrity of our elections.”

The outcome could have a major impact in November, with the possibility that voters could flip the seat for the GOP depending on who wins.

The Associated Press contributed to this report.