Adams County Public Information Officer Jim Siedlecki said the new error is also Runbeck's fault, blaming a malfunctioning piece of equipment at Runbeck's Arizona facility.
He said at least 94 ballots have incorrect congressional district or state legislative candidates, municipality, school district, or other special district questions.
"Thus far, we have uncovered at least six (ballots) that were returned, but we're reaching out to all 94 affected voters to get them correct ballots," Siedlecki said.
He said it was Runbeck that provided the number of voters impacted and all of their names. 7NEWS asked if the county could trust Runbeck to provide the accurate number of those affected.
"Do we trust Runbeck at this point? It's lukewarm," Siedlecki said. "And at some point here, we have to start questioning their process and their machines. But it’s a small number (of ballots), let's keep that in perspective."
Runbeck was awarded the contract to print ballots for Adams County following an open, competitive bidding process, officials said.
"We have used this vendor twice in the past without issue," said Adams County Clerk & Recorder Karen Long. "These mistakes are very disappointing."
The company prints ballots for several other Colorado counties, including Mesa, where there were also mistakes on about a hundred ballots pertaining to a measure about allowing the sale of retail marijuana.
Runbeck admitted Sunday evening that 8 voters in Larimer County received the wrong precinct ballots.
The company also reportedly sent faulty return envelopes to hundreds of voters in Maricopa County, Arizona.
"We regret that any voters have been inconvenienced, but please note in your report that all voters will have the correct ballot in time to cast their vote in this election," Chief Executive Officer Kevin Runbeck said in an email.
Siedlecki said he did not believe the problems would prompt an entire a new election in the county because of measures in place to address the mistakes.
"That will be decided by the secretary of state who has full confidence in the integrity of our election," he said.
Adam Brookhart, one of the voters who got two ballots, said what's happened is a big concern.
"Voting is something that's sacred, and this definitely opens a door potentially for voter fraud," Brookhart said.
Efforts are underway to contact the 94 affected voters who will be issued a correct ballot, if they have not already submitted a ballot. All ballots will receive an additional level of oversight in order for any incorrect ballots to be identified and new ballots issued. In addition to existing verification methods, election judges will now manually confirm that the voter received the correct ballot before that vote is counted. Voters may access www.govotecolorado.com and View My Sample Ballot to confirm their correct ballot.