America is still finding its lead pipes. The clock now runs to 2027.

The dangers of lead have been understood for more than a century. It is one of the most thoroughly studied poisons in existence. And yet the Environmental Protection Agency estimates that roughly nine million service lines in the United States — the pipe running from the water main to a building — are still made of lead.

Chicago alone accounts for something like 400,000 of them, more than any other American city, and a large share of its housing stock is connected by one.

What lead does to a child is the part that makes this urgent rather than merely embarrassing. Low-level exposure in childhood is associated with lower IQ, attention and behavioural problems, slowed growth, hearing damage and anaemia. The critical word is that these effects are not reversible. You cannot treat a child back to where they would have been. Both the EPA and the Centers for Disease Control state plainly that there is no known safe level of lead exposure in children — which is a different kind of statement from a limit, because it means every reduction is a real gain and no threshold is a finish line.

Water is not the only route of exposure — paint in older housing remains a major one — but it is a steady, daily one, and it is invisible. Lead gets into drinking water by corrosion: from the service line, from lead solder in the joints, from brass fittings. Buildings plumbed before 1986 are the usual suspects. Nothing about the water looks, smells or tastes different.

Two pieces of household advice circulate, and it is worth being precise about both. Running the tap before drinking does genuinely reduce lead that has been sitting in the pipe overnight — but it does nothing about lead picked up while the water is flowing, and it depends on someone remembering, every time, in every building, including at three in the morning for a bottle. Boiling does not help at all. It makes matters worse: the water evaporates and the lead stays behind, so the concentration goes up.

The regulatory position has moved recently, and the dates matter. Under the Lead and Copper Rule Improvements, water systems had to file an initial inventory of their service lines by October 2024. The rule requires lead service lines to be replaced within ten years, and lowers the action level for lead from 15 micrograms per litre to 10. The next hard deadline is 1 November 2027, when systems must produce a baseline inventory, a replacement plan, an updated sampling plan — and a list of the schools and childcare facilities they serve.

That last item is the one we would underline. It is a rare instance of drinking water regulation aiming directly at the buildings where children spend their days and do not choose their tap.

It also shows how much ground there is to cover. A study of states requiring schools to test their drinking water found that a substantial share of schools tested had at least one sample at or above their state action level — and state action levels vary, some sitting well above the federal one. Testing is not the same as fixing, an inventory is not a replacement, and a deadline in 2027 for a plan means pipes coming out of the ground for years after that.

In the meantime children keep drinking. That gap between a rule existing and a tap being clean is exactly the space this Foundation works in.

What actually removes lead is worth knowing, because it is not everything sold as a filter. Look for a filter certified to NSF/ANSI Standard 53 for lead reduction, or reverse osmosis; a plain carbon taste-and-odour filter is not the same thing, and a certified filter that nobody replaces on schedule stops working silently. That last point is why the Foundation pays for servicing and not only for equipment — an unmaintained filter is more dangerous than none, because everyone concerned stops worrying.

One number from our own side of the work. When our partner NearonYdor had its Twin system tested by the Chemistry Department of the National and Kapodistrian University of Athens, the ordinary tap water used as the baseline already contained lead at 2.20 micrograms per litre before anything was added for the test. That is well under any legal limit, and it is not zero. After filtration, lead and the other seven metals tested were all below the limit of detection. Legally compliant and actually clean are two different measurements, and children live in the space between them.

Sources: US Environmental Protection Agency, Lead and Copper Rule Improvements and service line inventory requirements; EPA and CDC guidance on childhood lead exposure; laboratory report, National and Kapodistrian University of Athens (Chemistry Department).