Water systems at an observatory, a prison and mobile home park in Arizona are among those that have tested above the federal limit for lead in the past three years, according to an Associated Press analysis of federal data.
No amount of lead is considered safe, but the U.S. Environmental Protection Agency says samples over 15 parts per billion trigger notification to customers and steps to control exposure to lead, which can damage children's brains, cause behavioral problems and make adults sick.
The AP found that nearly 1,400 water systems serving 3.6 million Americans nationwide have violated the federal lead standard at least once between Jan. 1, 2013, and Sept. 30, 2015. In Arizona, 14 out of more than 950 water systems fell into that category, according to the EPA.
Most of those are on the state Department of Environmental Quality's watch list, and the agency says it is working with system operators to fix problems. Hundreds of other systems across Arizona have reported varying amounts of lead since the EPA's rule on the contaminant went into effect in 1991.
Many times, lead piping is to blame. The state Department of Corrections has replaced faucets in mechanical rooms and restrooms at the prison in Florence, where it's believed lead was used in the fixtures or to solder the joints, and conditions have improved, spokesman Andrew Wilder said.
Drinking water for inmates and staff has not been affected, he said.
Oak Creek Elementary School, one of those on the state's watch list, is replacing plumbing in two classrooms after tests in 2013 showed lead exceeded federal limits at two drinking fountains, said David Snyder, business manager for the Cottonwood-Oak Creek School District. The fountains now are under the limit but still present some lead, Snyder said.
The lead isn't raising concern for the school because the water sources haven't been used since 2014. The students in the classrooms already were drinking bottled water because they didn't like the taste of the fountain water, Snyder said.
Water from lead pipes in decades-old buildings at the Kitt Peak Observatory in Tucson also have produced elevated readings -- including one that was eight times the federal limit. The EPA, however, uses a sample set to determine whether a system is in compliance.
The observatory's facilities manager, John Dunlop, said staff, researchers and visitors drink bottled water. Signs posted around the campus remind people using piped water in older buildings to flush the system before washing or showering.
The Tonto National Forest will be taking down notices it placed around campgrounds, a visitor center and office at Roosevelt Lake after test results Thursday showed the system now is in compliance, forest spokeswoman Carrie Templin said. Sampling from 2014 showed up at 40 parts per billion, which the forest believes was a fluke, but now is under the limit, she said.
Notification to customers was delayed in at least two cases when water systems were over the limit, including the Oak Creek School and the forest. Templin said a consulting firm collects the water samples. The forest and the Arizona Department of Environmental Quality are supposed to be notified of the results, but Templin said the forest wasn't aware of the results until the state sent a letter in February.
"Somehow it got messed up," she said.
Snyder had a similar story in the school not finding out about elevated lead levels until years later.
"There are a lot of different entities that had fault on this," he said. "We're one of them. We're changing our procedures and our testing company and everything."
Department spokeswoman Caroline Oppleman said the agency plans to have a system in place by June to notify consumers of any highly tainted drinking supplies when public water systems fail to do so.