Anthony Vazquez/Sun-Times file A new school year is just over a month away, and over 340,000 Chicago students — a good number of them still too young to be vaccinated — are slated to return to school buildings five days a week. Nearly 32,000 teachers and other school staff will return to those buildings, too, all amid a newly resurgent pandemic fueled by the more contagious Delta variant of the coronavirus. To keep the potentially deadly virus at bay, every one of the Chicago Public Schools’ 600-plus buildings had better be well-ventilated — and impeccably clean. Editorials Immaculate schools should go without saying of course, pandemic or not. But we’re making special note of the issue following the news, reported by the Sun-Times’ Lauren FitzPatrick and Nader Issa, that CPS is poised to offer another contract to Aramark, the firm with a well-documented track record of failing when it comes to making sure schools are kept pristine.