PORTLAND, Ore. (KOIN) – With less than one week before Election Day, Clackamas County is experiencing ballot processing delays amid "persistent" mechanical issues with a mail ballot sorter, the county elections office announced Thursday.

The issue started the week after ballots were mailed to Clackamas County voters, officials said -- explaining the mail sorter abruptly stops moving ballots. This makes it challenging to process large batches of ballots without interruption.

The Clackamas County Elections Office said they previously received on-site help from the mail ballot sorter company, which is returning to the office for the second time for repairs.

Typically, the county explained, all ballot envelopes are processed through the sorter, which takes a picture of the back of the envelope and the barcode is scanned to verify the envelope is valid and from a Clackamas County voter.

Those pictures are then reviewed by staff to compare the signature on the envelope with the signature on the voter's registration record. After the signature is reviewed, ballot envelopes are processed through the mail ballot sorter a second time and split into two categories: approved ballots and challenged ballots – meaning the signature could not be matched.

Voters who submitted a challenged ballot are contacted to cure the signature, Clackamas County Elections office explained.

The elections office said the mechanical issue is also delaying voters’ ability to look up the status of their ballot.

As the elections office awaits repairs, Clackamas County Clerk Catherine McMullen directed elections staff to process ballots using hand scanners. McMullen explained scanning ballots by hand is an established process and is used in smaller Oregon counties. During this process, ballot signatures are still reviewed by staff.

As of Wednesday, the county has processed more than 82,000 ballots – noting at the beginning of the day Wednesday, the elections office had an estimated 40,000 ballots to process in addition to the 12,000 ballots received in the mail and at ballot drop sites.