Toxic levels of lead have contaminated the water at Healdsburg Elementary School since at least November, a fact which school officials are just now making public. The water, with contamination levels reportedly 59 times higher than the EPA required action level, was found coming out of school drinking fountains. School officials, for their part, admit that there's no way to know for sure how long the water has been contaminated, but are adamant that the threat of exposure is over.

So reports The Press Democrat, which notes that school officials have been stocking the school with bottled water since November.

“Currently, no student has any contact with drinking water that is of concern,” the superintendent of the Healdsburg Unified School District, Chris Vanden Heuvel, told the paper. “We are working with the public health department to make sure that there are no health concerns for our students. If we discover that there are, we will be issuing an advisory with the county health department.”

Parents, who were only notified of the lead contamination earlier this week, weren't the only one kept in the dark — the Sonoma County Health Department wasn't alerted to the contamination until this week either.

School officials say they intentionally held off on notifying parents and county health officials until they had a corrective plan in place. That claim, however, may not be enough to mollify all the students' parents — at least one of which feels she was kept in the dark.

“That seems like a big chunk of time to have passed,” one student's mother, Michelle Schultz, told the publication. “I was irritated.”

Superintendent Vanden Heuvel, for his part, stated the obvious: That there is no real way to know how long the water has been contaminated, and that students could have been exposed for years.

“There’s no real good way for us to know; it has to do with the deterioration of the materials themselves in the plumbing system,” he noted. “There are no parameters that we have for water testing, it’s not something that’s mandated."

Lead, of course, is particularly detrimental to the development of children, and exposure at high levels can lead to long-term developmental problems and brain damage.

Related: Environmental Activists Claim Techie Fave 'Soylent' Might Give You Brain Damage