A water fountain is covered because of lead in the drinking water at Creston Elementary School in Portland, Ore. (Beth Nakamura/The Oregonian/OregonLive)

Tests last summer showed troubling levels of lead in the water at Summit Township Elementary School, perched on a quiet hilltop outside Butler, Pa. But for the next five months, no one told the parents of Summit’s 250 students.

When officials alerted families to the potential lead contamination in January, the dominoes fell quickly. The district superintendent and assistant superintendent resigned. The school board hired an independent investigator. Administrators shuttered Summit and moved students to another building several miles away. And the mother of a kindergartner filed a federal lawsuit, saying the inaction had created “a school full of poisonous drinking water.”

Nearly two years after a water crisis in Flint, Mich., triggered renewed pressure for lead testing and remediation in schools across the country, many districts continue to stumble.

School systems throughout the country have wrestled with lead in water for decades, in part because of the intractable problem of lead-bearing fixtures and pipes in aging buildings. In addition, the overwhelming majority of schools face no state or federal laws that require testing, and crimped budgets and understaffed districts mean water testing seldom rises to a top priority.

But in a growing number of places, parents have become increasingly exasperated by the lack of transparency and the delayed notification that often have accompanied the problem.

“We were not informed at all,” said Jeffery Hawkins, who said he learned from his daughter that fountains at her Milwaukee public school had tested for elevated lead levels. The school system had proactively checked thousands of taps and fountains — promptly taking suspect ones out of service — but even then faced criticism for not quickly publicizing the test results.

In Portland, Ore., irate parents demanded accountability last summer after the state’s largest district failed to immediately inform them about elevated lead levels detected in taps and fountains. The superintendent stepped down after the release of a scathing report that detailed the district’s failure to fix problems, and months later, Portland is still providing bottled water at its 90 schools — at an annual cost of about $850,000.

Officials are hoping that voters approve a record $790 million bond in May to modernize the city’s schools, which average 77 years old. The measure includes nearly $30 million to rectify water-quality problems.

“It’s definitely been a very challenging year. There’s been a lot of pressure from the community, very understandably so,” said David Hobbs, the district’s senior director of facilities. “We’ve tried to stem some of that by being much more transparent. . . . We’re trying to rebuild trust.”

Indeed, rebuilding trust has become an increasingly common theme in systems small and large, even as they grapple with aging buildings, strained budgets and a regulatory vacuum. The latter could be changing, though.

In January, Illinois Gov. Bruce Rauner (R) signed bipartisan legislation requiring that all elementary schools and day-care centers test every drinking-water source for lead contamination and notify parents of the results. But the new law, which came after widespread lead-in-water problems surfaced in Chicago public schools, mandates only one-time testing.

“This is a social justice issue. It’s an education issue. It’s a moral imperative,” Rauner said in a speech about the measure. “It is way past the time we deal with this issue.”

New York has gone further, with a new law requiring schools statewide to test drinking water for lead. Its biggest system, New York City, tested tens of thousands of fixtures last year. But criticism that the methods used were flawed and incomplete led to a second round of testing, which turned up nine times as many water sources with lead levels exceeding the federal “action level” of 15 parts per billion.

In California, Assemblywoman Lorena Gonzalez Fletcher (D) is pushing legislation to require schools to test their water supplies.

The measure, which has passed one key committee, would require annual tests for schools constructed before 1986, when Congress prohibited the use of most lead solder, pipes and fixtures. For those built after 1986, tests would have to take place every three years. Administrators would have to notify parents within 24 hours if contaminated water is found.

“It’s shocking to me we’ve gone this long and still don’t know how much lead is there,” Fletcher, whose San Diego-area district has wrestled with the problem, said in an interview. “The most basic function of government is public safety and public health.”

Health officials agree that no amount of lead exposure is safe, whether through water, air, dirt or old paint. Even small amounts risk irreversible cognitive and developmental damage, particularly in young children.

Yanna Lambrinidou, a Virginia Tech faculty member who has long studied lead contamination in water, said she is heartened that a growing number of schools are paying more attention to the problem — even though action often comes after pressure from parents.

But one-time testing isn’t sufficient, she said. “The science of lead in drinking water is very clear that lead release from plumbing tends to be highly variable at individual taps,” Lambrinidou said.

That means a tap that tests safe one day — no detectable lead — might show alarming levels in the water if checked another day.

“It’s like a lottery ticket,” she said. “I don’t think we can base a nation’s response to lead in school drinking water on a lottery game. Right now, that’s what I fear most of the states doing anything at all about lead in water are doing.”

A better approach, she said, would be one that several states and the District are starting to embrace: Assume any tap or fountain poses a potential health hazard, no matter what a test shows. District schools have placed filters on every drinking-water source, for example, with plans to regularly test even the filtered water.

But for many school systems across the country, the lack of routine testing requirements means lead in water often is discovered haphazardly, if at all.

In March, a 16-year-old high school student in Boothbay, Maine, used her honors project to test her school’s water. School administrators followed up on her findings and confirmed that drinking-water sources inside the local high school and elementary school showed worrisome lead levels.

Fountains were shut down. Notification letters went home to parents. Two more schools joined the list of others across the nation getting regular deliveries of bottled water.