The city doled out $38.5 million in back pay to schools staff who were wrongly required to work overtime on a buggy special education data system, according to payment details released today by the education department.

Nearly 30,000 therapists, special education teachers, paraprofessionals, guidance counselors, social workers and psychologists received the overtime payments this month after an independent arbitrator ruled in January that the Department of Education violated the United Federation of Teachers’ contract. The first round of payments, on April 12, totaled $2.6 million for 1,700 occupational and physical therapists and the second and final payment — $35.9 million — went out to the rest of employees today.

The total number of educators who qualified for overtime far exceeded the UFT’s estimates, which hovered at around 10,000. The UFT filed the labor complaint in mid-2011, charging that staff should not have been required to work outside of their contractual school day.

The unintentional overtime centered on time that educators spent plugging data into the Special Education Student Information System. According to teachers and union staff, the program does not have basic functions that are routinely found in other computer programs, such as an ‘auto save’ feature.

In a statement today, UFT President Michael Mulgrew said that SESIS continues to be unnecessarily time-consuming for teachers and a wasteful example of the city’s pricey technology contracts.

“Thousands of hours that teachers could have spent helping kids were wasted trying to get this boondoggle of a computer system to work,” Mulgrew said.”But just as CityTime cost the city millions of dollars year after year, until SESIS is fixed or scrapped it will continue to be a money pit.”

Department of Education officials defended SESIS, which tracks student attendance and keeps a record of services that special education students receive.

“Keeping accurate and complete records on services provided to special needs students is necessary to ensure that we are providing quality services, and we are working to ensure that all staff are properly compensated in accordance with the arbitration award,” Connie Pankratz said.