Harmful metals and bacteria are lurking in the pipes at shuttered schools as students near a return to class, experts warn

• Schools across the US are slowly welcoming students back to campus.
• Some campus buildings have sat vacant for nearly a year as class instruction moved online.
• As a result, experts say harmful metals and bacteria are likely lurking in the pipes.

As schools across the country begin reopening after months of closure, some districts are learning that hazardous material accumulated in their plumbing systems, and experts say stagnant water poses health risks to students and staff.

In Michigan and North Carolina, reports of elevated lead levels and bacteria in the water are scaring school officials. Their worry is that students and staff might be exposed to dangerous drinking water.

Lead can enter water when plumbing materials that contain it begin to corrode, according to the Environmental Protection Agency. Flushing school plumbing systems with fresh water is one way to ensure hazardous material does not form or linger in the water. But because of concerns related to the pandemic, schools across the United States have generally been closed for months.

According to the Environmental Protection Agency, lead is a toxic metal "linked to damage to the central and peripheral nervous system, learning disabilities, shorter stature, impaired hearing, and impaired formation and function of blood cells" in children.

There is no safe level of lead in drinking water, Elin Betanzo, a water engineer and the founder of Safe Water Engineering, a Michigan consulting firm that works to improve access to safe drinking water, told Insider.

Ann Arbor, Michigan, officials have previously said their schools followed flushing guidelines regularly during the summer when most students were not present.

In October, however, tests of the water in several Ann Arbor schools showed high bacteria levels, leading officials to recommend flushing the pipes three times a week, up from two, according to a Chalkbeat report.

In North Carolina, the assistant superintendent of the Chapel Hill-Carrboro City Schools district, Patrick Abele, said one of his schools detected traces of copper and lead, the local news outlet Chapelboro.com reported.

School buildings in the Chapel Hill-Carrboro City Schools system have been closed since March 2020 when schools and businesses across the US shifted to virtual learning and remote work.

At present, school leaders intend to allow students to return to classrooms in April, though legislation that passed both chambers of the North Carolina state legislature may force school leaders to reopen schools by mid-March, school officials said.

District representatives said they will continue to test the water and flush pipes as schools prepare to resume in-person learning.

Water quality issues have also emerged in other parts of the country, including Ohio, Pennsylvania, and New York, according to Chalkbeat.

School districts elsewhere are taking steps to prevent the accumulation of harmful bacteria and lead in water pipes.

Hawaii public schools, for example, partnered with the state health department to test tap water for lead. Testing in select schools began in February and is expected to continue through the end of the year, said Nanea Kalani, communications director for the Hawaii Public School district.

"Nearly 75% of all public school students have resumed in-person learning," Kalani told Insider. "Our facilities are consistently being utilized," Kalani added.

About two dozen schools across the Hawaii islands will undergo routine testing this year.

Some school districts do not anticipate being caught off guard by hazardous material in drinking water.

The Miami-Dade County schools district, one of the largest in the US, said lead exposure in particular is not a concern. "Miami-Dade is unique in that lead service lines have never been utilized and our water supply comes from the underground Biscayne Aquifer," said Elmo Lugo, media specialist at Miami-Dade County Public Schools.

"Groundwater, unlike surface water sources, is filtered through the sedimentary layers of sand and limestone, which naturally filters out any traces of surficial lead."

In the event of any unprecedented lead exposure, however, the school district has a partnership with what Lugo described to Insider as a governmental agency that stands ready to distribute bottled water to all sites.

Additionally, Lugo said Miami-Dade County schools "were not closed for a prolonged period of time without constant maintenance and/or capital improvements." Schools were closed from March 16, 2020, and began reopening on October 5. During that time, Lugo said, each school building within the district followed flushing procedures and other measures to track and maintain the water quality.

Pipes also undergo routine testing by the Water and Sewer Department and the Florida State Health Department.

"These agencies rigorously test all of our schools on a regular basis. If they find anything, they notify us immediately," Lugo said. "We are very proud of our proactivity in keeping each school free from secondary lead exposure and bacteria."

New York City Public Schools, Chicago Public Schools, and the Los Angeles Unified School District - the three largest public school systems by enrollment in the US - did not return Insider's requests for comment.

While school officials are focused on keeping COVID-19 out of classrooms, experts say dangers could be lurking in the pipes

"The longer we let it sit there, potentially, the greater concentration of chemicals are in the water," said Andrew Whelton, a water quality researcher and professor of civil engineering and environmental and ecological engineering at Purdue University.

Lead, copper, zinc, and other heavy metals that can be found in stagnant water pipes can have "acute health effects" if ingested, Whelton said.

But these concerns aren't regularly considered, he said, because water systems in places like school buildings don't typically sit stagnant for months on end.

"When you would try to publish a study, showing that you let water sit in pipes for a very long time, scientists would reject it and say, 'this never happens,'" he said. "So, you would have a hard time publishing it because people would say it's unrealistic."

Both Whelton and Betanzo said there aren't federal standards requiring schools to test the quality of their water systems, leaving it up to the schools themselves to decide.

Federal requirements only apply to schools when they're considered a public water system. Most are not, Whelton said.

"Most schools receive water from a public water system," Whelton said. "And in that situation, the assumption has been that if the public water system delivers water to the water meter, and that's safe, then clearly throughout the entire school, the water is safe all the time forever."

Water can also vary in quality in different parts of the same schools, the experts told Insider. Rarely used faucets, drinking fountains, or entire areas of school buildings with less traffic, can also have higher levels of contaminants than water in other parts of the campus.

"You could have some really new water fountains with water bottle filling stations, and then maybe the school ran out of money and couldn't replace the really old water fountains," Whelton said.

"And those are the ones with high levels of lead," he added. "The school can determine where they're going to test. They don't have to test the oldest ones. They don't have to test the most used ones, and there's really not good guidance for these schools."

Stagnant pipes can lead to the risk of harmful bacteria, like Legionella

In addition to harmful metals that seep into stagnant water, Whelton said that the lack of running water can allow a "slime" layer of bacteria and other organisms known as a biofilm to grow, allowing harmful bacteria, like Legionella - the cause of Legionnaires' disease - to enter the water.

"When water is moving, you have water flowing, and because of that, you have shear forces that don't allow the slime layer to get that thick," he said. "And the thicker of the slime layer, potentially the easier it is for pathogens and disease-causing organisms to hide in it. And when the water stops moving, then the bacteria and other organisms will come out into the water."

Schools that had partial shutdowns or adopted a hybrid system of virtual and in-person instruction are likely in a better situation, Betanzo said, as just some movement of water can prevent metals and bacteria from seeping in or growing.

"You can have all your water in great condition in your community," said Betanzo. "You're using it all the time, but once it hits that school building and nobody's using it, the water stops moving. We call that water age."

As the water in pipes ages, the disinfectant added at water-treatment facilities dissipates and the biofilm grows.

"If there were a few microorganisms in the water, they get to grow because there's no chlorine or chloramines in there to control their growth," she said.

And schools that say they're flushing their pipes before students return may not be doing enough to entirely eliminate the hazards, she added.

"You want to make sure you are bringing fresh water to the entry point of the school and then using that freshwater to push the old water out," Betanzo said.

"If you're not doing it methodically in that order, you could end up just pulling bad water around and around the building, especially in a building with more complex plumbing systems, like in larger high schools," she added.

More complex cleaning of a school's water system by third-party companies may also be necessary to properly remove bacteria clinging to the pipes. For now, Betanzo said she sends her own child to school with a large bottle of water each day.

She also recommended students and staff keep their face coverings on during the day - even when alone in areas like the bathroom. While Legionella grows in water, it's only harmful when its particles are inhaled, she said. Face masks to prevent COVID-19 spread can also prevent Legionnaires disease, she said.

Have a news tip about the water quality at your child's school? Contact these reporters at: cperrett@insider.com and ydzhanova@insider.com