Missoula County Public Schools found levels of lead above the physician-recommended amount in about 80 percent of water tests in the last two years, according to a new report by Environment Montana Research & Policy Center.
The physician-recommended standard of 1 part per billion (ppb) is significantly lower than the federal law limit set by the Environmental Protection Agency of 15 ppb, at which point utilities are required to take action toward reducing the amount of lead in the water.
But experts, including the EPA, the Centers for Disease Control and Prevention, and the American Academy of Pediatrics, say the 15 ppb limit, set in the 1990s, is not a health-based standard, and that there is no safe blood lead threshold for children.
Missoula County Public Schools is not required to test the lead levels in its drinking water, but does voluntarily. Environment Montana, an environmental advocacy nonprofit, requested records of all MCPS lead tests from the last two years. It found that of 140 tests, 109 — or 78 percent — found lead in the water above 1 ppb.
Seeley Swan High School had the highest amount of lead in its water, at 28 ppb, as was reported in October 2017. It was the only school that tested above the 15 ppb legal EPA limit.
The four water fixtures found at Seeley Swan with high lead content were replaced, and a filter has been installed, according to MCPS spokesperson Hatton Littman. MCPS Superintendent Mark Thane said an environmental consultant has found the potential source of the lead: a backed-up abandoned water line near the school’s water pipe.
This summer, changes will be made to how the school gets its water and the pipes will be flushed to rid them of accumulated lead, Thane said.
Rattlesnake Elementary has the next highest lead content in its water, with 14 ppb found in the water of one of the classrooms — just under the 15 ppb threshold. Sentinel High School had 13 ppb, Lewis and Clark School had 12 ppb in the nurse’s office, and Big Sky High School had 10 ppb in kitchen sinks. Russell Elementary also tested positive for 10 ppb in a girls’ restroom.
Most tested under the 15 ppb limit, but exceed health recommendations of 1 ppb. All other schools tested under 10 ppb.
Thane said MCPS tested the water in all of its schools as they undergo major renovations with the Smart Schools 2020 bond project, to ensure a major infrastructural issue wouldn't be discovered after the renovations were finished. Significant portions of the bond project will go toward mechanical, electrical and plumbing upgrades, Thane said, and lead levels are now on the district’s radar.
He said he suspects the lead water levels found in MCPS, with the exception of Seeley Swan, are likely similar to homes and other buildings in the rest of Missoula, as the water distribution system is shared.
The Safe Drinking Water Act requires the EPA to determine the highest level, called a "maximum contaminant level goal," of lead allowed in drinking water before adverse health effects will begin to occur. This level is based solely on health effects, and is not used for legal enforcement. For lead in drinking water, the EPA’s maximum contaminant level goal is zero, meaning the only amount of lead in drinking water that’s healthy is none.
But infrastructure built with lead-containing pipes has made reaching that goal next to impossible for most cities.
Lead can build up in the body over time, or bioaccumulate, and is particularly harmful to children, as their bodies tend to absorb more of it. According to the EPA, even low levels of lead in the blood of children can result in behavior and learning problems, lower IQ and hyperactivity, slowed growth, hearing problems and anemia.
In rare cases, ingestion of lead can cause seizures, coma and even death.
Lead primarily enters the water supply through pipes, which corrode at different rates based on the acidity of the water passing through them. Older pipes, installed before federal regulations limited their legal lead content, are also more likely to leak lead into the water.
The EPA instituted the Lead and Copper Rule in 1991, which requires public water systems to monitor for lead in drinking water. But unless a school runs its own water system, which MCPS does not, it is not required to conduct tests.
“There are some schools that are hooked up to a municipal water supply, so they're not considered a public water supply,” said Montana Department of Environmental Quality spokesperson Jeni Garcin. “In those instances, they can test voluntarily and they can submit results to us and we can offer recommendations, but we can't do any enforcement.”
Garcin said DEQ uses the 15 ppb standard for determining whether lead levels are too high.
“The EPA sets those standards and there’s science behind that, but that's not our lane,” Garcin said. “The EPA sets those standards and we enforce those standards.”
Since passing the Lead and Copper Rule with the 15 ppb action level, the EPA has tried to stress to the public that the number doesn’t indicate the point at which lead levels become unhealthy. In a 2016 paper, the EPA wrote with suggestions for revising the law, saying:
“Although public discussion often mistakes the action level (15 ppb) as having significance in terms of health impacts, EPA has consistently emphasized that the health-based maximum contaminant level goal (MCLG) for lead in the current LCR is zero and that there is no safe level of lead exposure.”
But reducing MCPS water lead levels to 1 ppb or less would be a costly project that would take years, said Michelle Hutchins, environmental health specialist at Missoula City-County Health Department.
“It’s a tough question because really, the less lead the better,” Hutchins said. “So you want to get it as low as you can. This report indicating that the American Academy of Pediatrics would like to get lead levels below 1 ppb is a great goal, but I think it’s probably going to have to happen over time because there's a cost associated with it.”
Hutchins said MCPS was proactive about testing its water supply in schools, and brought the results to the Health Department when Seeley Swan High School’s levels were above EPA’s 15 ppb action level. She said the school district acted appropriately in following EPA standards.
“The problem with lead is it’s being picked up in the distribution system. It’s something that is hard to deal with centrally. Some water tends to leach more lead from plumbing systems than other water. I don't believe that Missoula’s is particularly prone to that, but it does happen all over the country and it does happen here.”
Some temporary solutions that don’t require replacing the water distribution system do exist, such as using water filters and running the water to flush out pipes at the beginning of the day, Hutchins added. When water sits in pipes for longer periods of time, it picks up more lead, and flushing them out can get rid of the contaminated water.
"The goal is zero. Really, you want to get down as low as you can," she said. "But again, in something that's very very common, you have to do what you can economically."