Atlanta Public Schools wants 134 educators to repay a portion of last year's salary after the district determined it mistakenly overpaid them .

The $234,000 overpayment was uncovered by a human resources salary audit, according to a letter to educators. All the affected employees are certified, which includes teachers, principals and paraprofessionals. Employees were given two options: Have the money deducted from their March through August paychecks or turn in a lump sum payment by March 5. The average repayment is $1,700.

"It is a slap in the face," said E. Vincent Martinez, a fashion design teacher at Grady High School who owes $1,286.

Educators are paid using a salary “step” scale, which bases income on years of experience and level of education. Some educators were placed on the wrong salary scale, APS said.

Martinez joined APS in 2002 when new teachers were paid at a higher salary step as an incentive, according to emails between Martinez and the district.

But in early 2011, human resources notified Martinez he was being overpaid, he said. The incentive ended in 2005 after a compensation study, but the district failed to adjust Martinez's salary for six years.

His pay was reduced this school year, resulting in about $100 less per paycheck. And now the district wants Martinez to repay his excess salary from the 2010-11 school year.

Martinez said it's an insult, especially when APS is spending $600,000 a month to pay the salaries of about 120 educators placed on paid leave following a cheating investigation. Those employees have job protections under state law, which entitles them to a public employment hearing before they are fired. The district is delaying the process as to not disrupt an ongoing criminal investigation.

Atlanta Public Schools spokesman Keith Bromery said the overpayment occurred for various reasons related to data entry. In some cases, the wrong salary information was recorded when employees were first hired. In others, when data was updated. Errors were also made in promotion and demotion salary calculations.

"The district is putting in place system upgrades and process procedures to reduce the risk for reoccurrences of this type of situation," Bromery said.

But this isn't the first time an audit has raised concerns about the problems with the district's payroll. State auditors in 2007 reported about $591,000 in payroll errors. APS responded that the district found seven employees who were overpaid after being wrongly placed in a higher step on the salary scale. The district's next audit raised similar concerns, leading state auditors to conclude there were "holes in the payroll process."

Bromery said new Superintendent Erroll Davis is reviewing operations like payroll accuracy to ensure they are as efficient as possible.

Tim Callahan, spokesman for the Professional Association of Georgia Educators, the state's largest teacher advocacy group, said payroll errors occasionally happen, and districts have the right to ask for the money back.

"Our legal staff will work with the member and district to ensure the repayment plan is reasonable since the mistake is usually on the part of the district, not the teacher," he said.

But E. Rivers Elementary teacher Karen Mitchell Pinson, who owes $1,538, said she and other teachers may seek advice from an attorney in hopes of fighting the repayment. She recently earned a master's degree, and with it a pay increase, so she didn't noticed she was being paid at the wrong salary step until the district contacted her in the spring.

"Teachers who cheated are sitting at home and I am getting up at 5 a.m to come to work to do my best as teacher," said Pinson, who has been with the district almost 20 years. "It’s wrong."