Public schools in Portland, Oregon failed to follow US federal protocols and did not notify parents after high levels of lead were detected at two of its schools two months ago, the district said on Friday.

Traces of lead — a toxic substance that can damage the nervous system — were detected at levels exceeding the Environmental Protection Agency's maximum in 14 fountains and sinks at the Creston and Rose City Park schools in March, according to a statement released by the district on Friday.

In an email to parents and staff on Friday, Portland Public Schools spokeswoman Christine Mile admitted that, in violation of EPA protocol, water fixtures known to be emitting lead were not turned off and the district did not warn students, employees, and visitors not to drink it. After detecting the lead levels, Miles said the district took steps to repair and retest water fixtures but allowed the contaminated water to flow as usual in the meantime.

"We apologize for not following this protocol," the district said.

The district added that it "regrets not having notified families and staff as soon as the tests indicated that there were elevated levels of lead."

Related: Heavy Metal: Water Contaminated by Lead Is Poisoning Kids Across New Jersey

The Portland Public Schools announcement comes as water quality in schools and communities across the United States are under heavy scrutiny after high levels of lead were found in Flint, Michigan, a community of 100,000 people.

Public officials have been blamed for poorly handling the crisis in Flint as three state and local officials were criminally charged in April in an investigation into their handling of the lead levels.

A mother of two Portland school children said in an email to Reuters late on Friday evening that she was furious.

"I actually became a bit shaky, that type of heart-pounding mad. I [was] shocked that they would knowingly allow children to drink poisoned water," Elizabeth Silva said.

In a statement and a second email to parents on Friday, the district vowed to take steps to address the issue including shutting off drinking fountains throughout system and providing staff and students with bottled water until the end of the school year.

The district also said it will also use bottled water for all food preparation and disposable plates and utensils for the remainder of the year.

Results of additional testing at the two schools will be made public during the week of June 6 and water testing will be done across the district this summer, the district said.

Portland Public Schools also promised to assist in testing children for lead poisoning starting June 6. According to The Oregonian, the administration hadn't thoroughly tested drinking water in its schools since 2001, when testing revealed that 35 out of 40 school buildings had lead leaking into its drinking water, with levels as high as 162 parts per billion (the EPA's "action level" is 15 parts per billion.)

"It's now time for permanent changes," former superintendent Jim Scherzinger said in a press release.

Related: Lead Contamination Poses Hazards Far Beyond Flint

Recent investigations have shown that lead-contaminated water is an problem that afflicts schools and communities beyond Flint.

USA Today found almost 2,000 other water systems across 50 states where testing has shown excessive levels of lead contamination in the last four years. According to their analysis, Texas, Pennsylvania, New York, California, and New Jersey were the worst culprits. At one elementary school in upstate New York, lead levels were as high as 5,000 parts per billion – the EPA's threshold for the "hazardous waste" classification.

Consuming lead can be harmful even in small doses, particularly for young children and pregnant woman. Lead, a neurotoxin, can damage developing brains and reportedly cause low IQ's and attention deficit disorder. It can also cause kidney problems, increased risk of cardiovascular deaths and high blood pressure in adults, according to the EPA.