A school district in Northern California is facing criticism after revealing on Monday that nearly 200 drinking water sources in various schools contained lead levels exceeding their own safety standards.

The Oakland Unified School District, the 11th largest in California, informed families in a letter that over 1,000 faucets and drinking fountains were tested at 40 TK-12 schools to check for lead contamination. While nearly 83% of the water sources were below the district’s threshold of 5 parts per billion (ppb), about 17% were found to exceed this limit.

The district’s standard of 5 ppb is stricter than the state and federal guidelines, which set a higher action level of 15 ppb as determined by the U.S. Environmental Protection Agency.

Out of the 1,083 faucets and fountains tested, the district found 116 that had lead concentrations above 5 ppb but below 15 ppb. Additionally, 70 fixtures were detected with levels above the state and federal limits.

The district has removed the affected fixtures for repairs and plans to retest them until lead levels are at or below 5 ppb. As of now, 61 of these fixtures have been repaired and are awaiting retesting.

Parents have been urged to ensure that children carry reusable water bottles to use the filtered water stations available on campus.

Concerns from families and staff over communication

Despite public records indicating that schools underwent lead testing from late March to June, families were only informed of the outcomes on Monday. The district also acknowledged that some schools found out about the water testing just last week and more notifications would be made this week.

“Despite our meticulous approach, we did not effectively communicate with the communities at each school during the testing process, when we received results, or while we implemented fixes,” stated the school district in a letter to families.

“We are establishing systems to ensure that such communication failures do not happen again, allowing school communities to receive prompt notifications during similar testing,” the district added.

The announcement made on Monday has sparked outrage among parents and teachers who feel uninformed about the lead testing results. Staff members from Frink United Academy of Language, a school with test results above district standards, are calling for more transparency and highlighted that students have been exposed to lead since April, according to reports from KTVU and KGO-TV.

“We urgently demand safe drinking water for our students,” said Frick Academy Counselor Catherine Cotter at last week’s school board meeting, as reported by KTVU and KGO-TV. “We need transparency regarding what has been happening and why we were not informed until recently. The kids have been at school all summer consuming lead-contaminated water.”

Stuard Loebl, a 6th-grade teacher at Frink Academy, expressed his anger and disappointment to CBS News about the findings. “Students have been consuming lead-tainted water all this time; it’s infuriating, considering this was known even before the report was officially released,” Loebl said.

Health risks associated with lead exposure

According to the World Health Organization (WHO), lead exposure poses serious health risks, especially for young children. The Centers for Disease Control and Prevention (CDC) warns that even minimal lead levels in blood can result in harmful health effects for children.

“Lead exposure can impact several bodily systems,” stated WHO. “Young children are particularly susceptible to lead poisoning because they absorb 4 to 5 times more lead from sources as compared to adults.”

High lead exposure can cause severe damage to the brain and nervous system, hinder growth and development, and lead to learning and behavioral problems, as well as issues with hearing and speech, according to the CDC. These impacts may result in reduced IQ, difficulties with attention, and underachievement in school.

“The neurological and behavioral repercussions of lead exposure are thought to be irreversible,” noted the WHO.

Lower levels of exposure often go undetected due to a lack of obvious symptoms, according to the CDC and WHO. Public health authorities recommend that parents consult healthcare providers about possible blood lead testing for their children.