Chicago Public Schools officials say their efforts to improve school cleanliness are working, but data they released late Tuesday showed that one in four schools still failed “blitz” inspections despite heightened awareness prompted by Chicago Sun-Times reports.

Just ahead of the July 4 holiday, CPS released school-by-school summary results of inspections by central office staffers and employees of Aramark and SodexoMAGIC, which have major contracts to clean and oversee facilities services in the school system.

CPS officials still would not release copies of the new inspection reports, though.

Following the news reports of filthy conditions at many Chicago schools, 306 of the 408 schools examined between April and the last day of school passed, according to CPS.

That’s an improvement from an earlier round of inspections but still represents just three of four schools making the grade.

After a rodent infestation at a South Side elementary school, CPS quietly began a series of inspections last December and had completed 125 when the Sun-Times sought copies of the inspection reports. Documents the newspaper ultimately obtained showed 91 of the schools failed those inspections.

There was a 72 percent failure rate at the schools whose janitorial services were managed by Aramark.

The revelations pushed CPS into high gear, with schools officials agreeing to hire 200 more custodians this summer, with at least 100 of them to stay on during the school year.

On Tuesday, CPS spokeswoman Emily Bolton pointed to higher pass rates among schools where Aramark or SodexoMAGIC oversee all facilities services — such as landscaping and pest control — and not just janitors, as is the case at some schools.

Officials have been working to expand that model citywide. That was supposed to be done by July 1, but now CPS says it will take until just before the start of the school year.

“Our initial rollout has shown us that, when properly supported and implemented, [the new system] is far more effective,” Bolton said.

CPS also is privatizing its school engineers.

Chicago Teachers Union vice president Jesse Sharkey said, “Predictably, the mayor tried to sweep this evidence under the rug, as he does with every scandal in the schools he runs.”

READ SUN-TIMES’ ‘DIRTY SCHOOLS’ INVESTIGATION

• CPS’ dirty secret, March 28, 2018

• Dirty schools: CPS cheated to pass cleanliness audits, janitors say, April 8, 2018

• Reward for dirty schools? $259 million more from the Chicago Public Schools, April 22, 2018

• Dirty schools unacceptable, Chicago Board of Ed says, vowing to keep closer tabs, April 26, 2018

• Chicago Public Schools’ facilities chief is out after dirty schools scandal, May 31, 2018