The head of elections in Adams County said his office is responsible for 17,400 voters in Aurora receiving inaccurate ballots over the weekend and that corrected ballots will be dropping in the mail Friday.

“We made a mistake, and I own it,” Adams County Clerk and Recorder Josh Zygielbaum said Wednesday at a news conference at the county headquarters in Brighton.

The erroneous ballot directed voters in the Aurora portion of Adams County to select one at-large candidate in the Nov. 5 Aurora City Council race. But two at-large seats are up for election.

Parts of Aurora, a city of about 380,000, also lie in Arapahoe County and a sliver of Douglas County.

Zygielbaum said voters should wait for the corrected ballot to arrive in the mail before voting, and destroy the original ballot. However, they are permitted to simply vote for two candidates in the at-large race on the original ballot if they can’t wait for the replacement ballot to arrive.

The corrected, or second, ballot will take precedence in the event both ballots are turned in, the clerk said. Zygielbaum said it’s critical that voters fill out the entire corrected ballot if they want their votes for other races and measures counted.

“It’s very, very, very important that when you receive your second ballot, you do vote the entire length of the ballot and not just the one question surrounding the Aurora City Council at-large race,” he said.

As of Wednesday, Zygielbaum said only one or two of the erroneously printed ballots had been turned in. He said it will cost the county about $20,000 to print and mail out the new ballots.

After Leanne Wheeler, an at-large candidate in Aurora, posted an image of the erroneous ballot on her Facebook page , Zygielbaum wrote that Aurora’s city clerk initially sent his office the correct information, but “when the proof was created, an error was made in the number of candidates to vote.”

The erroneous proof was approved by Aurora’s clerk and “we moved forward with printing,” he wrote. But Zygielbaum, a former Thornton city councilman, said the error should never have occurred at his end to begin with.

There are six candidates vying for two at-large seats on Aurora’s council: Wheeler, Curtis Gardner, Angela Lawson, Martha Lugo, Thomas Mayes and Johnny Watson.

Mayes told The Denver Post on Wednesday that he’s “concerned about what this means for the integrity of this election.” Replacement ballots could confuse voters and decrease turnout, he said, although not sending replacements also would have been problematic.

Mayes, a longtime pastor, said he fears that the situation could suppress “the voices of the most diverse part of our city, and that is unacceptable.”

Asked if the county is concerned about the integrity of the election being tarnished as a result of the error, Zygielbaum said it isn’t.

“The integrity of the election is definitely intact,” he said.

Secretary of State Jena Griswold told The Denver Post that her office is working with the county on the error.

“Adams County will be sending corrected ballots out to all impacted voters,” she said. “The envelope of that ballot will indicate that it is the correct ballot, so voters should be on the lookout for their corrected ballots. Adams will count the corrected ballots first, and they will count the original ballots if those are the only ballot they receive.”

The latest error comes just one year after 61,000 Adams County ballots went missing during the general election. In that instance, ballots that had been dropped off by the print vendor at a mail facility to go out to voters were returned to a secure location and didn’t make it into the mail stream.

A subsequent audit ordered by the Adams County clerk found that neither the county nor its printing vendor, K&H Integrated Print Solutions, engaged in any misconduct. The incident was blamed on “miscommunication” between a driver and dispatcher for shipping company XPO Logistics.

Adams County wasn’t immediately made aware that a truckload of ballots had been sent back to XPO’s storage facility in Henderson, the audit stated. The ballots were mailed out in time for the election.

Adams County also came under scrutiny in 2014, when then-County Clerk Karen Long did not disclose that nearly 200,000 ballots in that November’s election could be traced back to individual voters.

“We’ve got something happening in Adams County that we have got to dial in on,” Wheeler said. “This is not good,” she said of the latest ballot error.

Zygielbaum said he first became aware of the situation after receiving a call from Griswold shortly before midnight Tuesday, “which is never the way you want to end your evening when you’re county clerk.”

Staff writer Anna Staver contributed to this report.