The lead in water crisis in Flint, Michigan comes as no surprise to Marc Edwards or to Yanna Lambrinidou.
They saw almost the same thing happen in Washington, D.C. more than a decade ago, and they say many cities and towns across the United States are at the same risk.
"I'm horrified. I'm unsurprised. We could see this coming," said Edwards, a civil engineering professor at Virginia Tech who's helped expose some of the weaknesses in water safety practices.
Lambrinidou, president of Parents for Nontoxic Alternatives, uses almost the same words. "I am horrified but also I really am not surprised," she said.
Like Flint, Washington D.C. suffered a rise in lead levels that wasn't discovered until after many people, including children and pregnant women, had drunk the water for months. As in Flint, children in Washington, D.C. turned up with high levels of lead in their blood.
In Flint, the lead leached out after the city switched to another river for its water, and corrosive chemicals ate away a protective layer that kept lead in the pipes from getting into the drinking water. In Washington, it was a change in disinfection chemicals that did it.
What appalls Edwards, Lambrinidou and others is that ever after Congressional hearings, lawsuits, and national media coverage that went on for years after the crisis in the nation's capital, the same thing could happen again. And weaknesses in regulation that could help prevent the problem from happening have not been fixed, they say.
It's not hard to understand the problem. Plumbing goes into the ground and it's not usually changed out unless there's a major disaster. The reason's obvious: it's expensive and there are homes, streets and buildings on top of these pipes, says Lambrinidou, herself a Washington, D.C. parent who joined forces with Edwards during the crisis.
Until the 1950s, these galvanized pipes contained lead and had a layer of zinc inside to protect the water. But various chemical reactions can corrode the zinc away and then the flowing water can pick up lead.
It happened in Washington in 2001 when the city's Water and Sewer Authority (WASA) changed its water treatment chemicals. A third of the homes tested in 2002 had lead levels above 50 parts per billion (ppb). The Environmental Protection Agency says people need to act if their water lead levels hit 15 ppb.
Related: Here's What Lead Can Do to You
It took years for the full story to come out about how much lead got into the water — the Washington Post newspaper did much of the reporting on it — but one statistic indicates some very clear consequences: Stillbirths in the city rose by 37 percent in 2000 through 2003.
The study, published in the journal Environmental Science and Technology, showed the stillbirth and late miscarriage rate rose from 7.9 per 1,000 births in 1999 to 10.9 per 1,000 in 2000 and 12.9 in 2001.
Edwards, who wrote the study, co-authored another study that found as many as 42,000 children in Washington, D.C. were under the age of 2, or were developing fetuses, when the lead levels spiked in the city's water.
Lead can cause permanent brain damage and it's most dangerous to a developing brain. Kids can lose several IQ points, have behavioral difficulties and one study even showed those with severe brain damage may even be more prone to criminal behavior. There's no reversing the damage.
But there's also no way to definitively prove that lead exposure caused such subtle problems in any individual child.
WASA did not warn D.C. residents until 2004. Lawsuits, some of which are still pending, allege a deliberate cover-up.
"I've been afraid that the lies in D.C. would cause another D.C., which is playing out before our eyes," Edwards said.
The EPA has a regulation called the lead and copper rule that requires water suppliers to test drinking water for lead and warn people if they find it.
But Edwards and Lambrinidou say what local water authorities do is game the system so the lead doesn't show up in the tests. They can flush the pipes for long minutes at a time before testing, and they can remove aerators from the faucets that trap or at least slow tiny lead particles, making the water seem more free of lead than it really is.
"People are still doing it, right in front of EPA's nose," Edwards said. "If EPA wanted to, they could stop it in a second."
Lambrinidou says suppliers test a random sample of homes, but if 9 out of 10 homes test lead-free or with low levels of lead, they can say the water supply as a whole is safe.
"The water utility will still announce to the public that the water is safe to drink," Lambrinidou said.
The one home out of 10 that has high lead must be warned. "But they don't tell homes like yours that were not in the sampling pool of 100 homes," she said. "You can have severe citywide contamination that is causing miscarriages, fetal deaths and elevated child lead levels."
Lambrinidou says residents often do not know that the regulation puts some responsibility on homeowners to test their own water for lead.
"People don't know this," she said. "They leave people completely uniformed and unprotected."
Why would water companies deliberately ignore the risk?
"They are required to take remedial measures," Lambrinidou said. "The remedial measures can be costly to them in terms of both money and public trust."
Edwards says there's evidence that the same thing is happening in Flint as happened in Washington.
His group's requested — and made public — emails that show EPA officials knew as early as February 2015 that Flint residents might be drinking lead-tainted water because of high levels found at a home.
Edwards says the CDC and EPA both have failed the public by not cracking down on utilities. The CDC did revise a study that it admitted underplayed the severity of the problem in Washington, and CDC officials note they have no regulatory authority at all.
The EPA did not immediately respond to a request for comment from NBC News.
"Unfortunately, this is human nature," Edwards told NBC News. "If you make a mistake, it starts easily. If you think you can get away with it, you can wake up some day and you didn't intend to go down this path, but you poison an entire city."