Outraged parents are demanding answers as to why they were kept in the dark about a mold problem at their kids’ school.

The Poway Unified School District — located in San Diego County — sent an email to parents on August 22 informing them the Principal at Black Mountain Middle School had reported mold found in the classrooms ahead of the school year, KGTV reported.

The email was sent ten days after students had already returned to school from summer break. Varying levels of mold spores were found in more than a dozen classrooms, ranging from low to high, according to the email.

The email said rooms were cleaned on August 10 but that a “musty odor persisted in some areas.”

Some teachers were wearing N95 masks after mold was found in the carpets, desks and other locations in the school, KGTV reported.

The tests found that 8 classrooms had low levels of mold spores, two with moderate, and four with high levels, noting the results weren’t final and a complete report would soon be available.

Parents who contacted KGTV said this isn’t the first time mold was found at the school and said they want answers why they weren’t told about the current problem before they sent their kids back to school.

Looking on the middle school website, weekly updates from the Principal to the parents in the month of August do not mention one word about the discovery of mold.

The district said over the weekend the classrooms were all cleaned again and follow up testing was to be completed.

“Cleaning and remediation were completed over the weekend, including carpet cleaning, antimicrobial wiping of surfaces, cleaning air registers, and replacing HVAC filters,” District spokesman Josué Reyna told KGTV.

The district is currently looking into the carpet cleaning procedure before the school year was set to start as the possible cause of the problem.

Students at an elementary school in the same district recently had the start of their school year delayed, with students sent to a different campus to deal with mold issues.

In a letter from the Principal of Del Sur Elementary, parents were told the start of the year would be delayed by one week over “moisture-related concerns” in some of the classrooms found earlier in the month, Fox 5 reported.

Classes started on Aug. 24 and students are anticipated to return to their home campus by September 21.

The California Post reached out to the district for more information.