Could too much copper in the school drinking water be making your child sick?
For almost two years, Nashville schools have been testing for lead contamination.
But copper hasn't been something that anyone has talked about.
That all changed when a Metro Schools insider came to NewsChannel 5 Investigates with a water sample from one water fountain.
FULL STORY: Watch NewsChannel 5 at 6 p.m.
"It's settled some. You can see the crud there," maintenance worker Joey Combs said as he held up a bottle of water that turned green as he shook it.
Combs said he collected that sample at East Nashville Middle Magnet School, from a third-floor water fountain.
"That's the color that it came out," he explained. "If a student had just come in from playing outside and decided hey I want a drink of water and ran up to the fountain, that's what they are going to be a mouthful of."
NewsChannel 5 sent the sample to an accredited lab for testing.
In addition to lead, it contained 6,500 parts per billion of copper.
The EPA says anything over 1,300 parts can make you sick.
"We know that you can acutely get gastrointestinal symptoms, vomiting, diarrhea, my tummy hurts type of thing," said Dr. Mary Keown, a Nashville pediatrician.
She said she worries about school children who may have been exposed to high levels of copper.
In addition to the short-term effects of gastrointestinal distress, the EPA says the long-term effects can also include liver and kidney damage.
"We know that there is some data out there that says it may have psychological effects in terms of attentiveness and irritability -- as well as the fact that you don't learn well if you have a tummy ache now, do you?" Keown said.
NewsChannel 5 Investigates asked the doctor, "Is that something you would know to look for?"
"It's not something that we would routinely test for in any way," Keown answered. "I mean, it's typically not on our radar."
BREAKING: @MetroSchools used a testing method that may have masked the real level of lead contamination in its drinking water https://t.co/emh1DAFfyx
— Phil Williams (@NC5PhilWilliams) May 8, 2018
Lula Mosley, who has three grandchildren there, said a lot of children at East Middle have complained about stomach issues.
"If that water's like that on the third floor, trust me that water is in the cafeteria like that," Mosley said. "It's got to be on the second and the bottom floor. It's got to be on each floor."
A Metro Schools spokesperson ignored NewsChannel 5's request for an interview with the official in charge of the district's testing program.
A statement posted to the MNPS website, however, assures parents that the problem was due to a little-used fountain that "is located in a portion of the building that is not used by students."
Dr. Sanmi Areola, a toxicologist who serves as deputy director of the Nashville Department of Public Health, said: "At these levels, do I expect huge acute effects? Perhaps, the chances are pretty low."
Still, he said that, because the East Middle building was constructed in 1929, it's not surprising that there might a copper issue.
"Most of the problems that we have with lead and copper are typically from older buildings," Areola explained.
"With copper piping?" we asked.
"Copper piping, yes."
In fact, the school system doesn't test for copper.
But because the lead and copper issues stem from a common problem, Dr. Areola says either test can be used by school officials to figure out if something needs to be done.
"We can test for lead, we can test for copper, we can test for all of them," he added. "What's more important, though, is when we find these levels, we have to be diligent in taking steps that have been recommended."
Metro Schools has been replacing water fountains when it finds high lead levels.
In this case, officials disconnected a couple of fountains.
If the problem is in the pipes, one option would be to rip out the pipes and replace them, which would cost a lot of money.
But a cheaper option would be to install filtered water fountains in every school - something the district has been reluctant to do.
Recording Reveals Plan To 'Bypass' Lead Filters
Audio Sparks Outrage, Mayor Calls For Answers
MNPS Spokesperson Questions Need For Filters
School Official Resigns After Secret Recording
NC5 Investigates: Lead in School Water