1.7 Billion People Have a Water Problem That Isn't Chemistry

I sell water systems for a living. Office H2O, Greater Madison. So take this with whatever grain of salt you want.

But I read a WHO number this week that reset how I talk about my own job.

In 2022, at least 1.7 billion people used a drinking water source contaminated with faeces, and WHO estimates microbiologically contaminated drinking water causes about 505,000 diarrhoeal deaths every year (fact sheet dated September 2023). Not parts per trillion. Not long-term cancer risk models. Pathogens, this week, killing people.

That is not the problem in your breakroom in Middleton.

Two different problems that share a name

American drinking water regulation largely addressed the microbe problem decades ago. Under the Safe Drinking Water Act, EPA sets legally enforceable standards for roughly 90 contaminants, grouped into six buckets: microorganisms, disinfectants, disinfection byproducts, inorganic chemicals, organic chemicals, and radionuclides.

Look at the order of that list. Microorganisms come first. Disinfectants come second. That's the whole story of 20th-century water treatment — kill the thing that kills you fast, then manage the taste.

The stuff we argue about now sits in the other four buckets. Chemicals. Slow ones.

Which is why the new rules are all chemistry

In April 2024, EPA finalized the first national drinking water regulation for PFAS — 4.0 parts per trillion for PFOA and PFOS, 10 ppt for PFHxS, PFNA, and GenX, plus a Hazard Index for mixtures. Public systems have to complete initial monitoring and tell the public what they found by 2027, with MCL compliance in 2029. Update, September 2026: in May 2026 EPA proposed letting systems request until 2031 to comply and separately proposed rescinding the limits for PFHxS, PFNA, GenX and the mixture rule; the 4.0 ppt PFOA and PFOS limits stay as written, and final action was still pending when I checked.

That's not a hypothetical exposure. A 2023 U.S. Geological Survey study estimated that at least 45% of U.S. tap water contains one or more PFAS, with detections more common in urban areas and near known contamination sources.

And the health end of it isn't vague. ATSDR's summary of the research associates higher PFAS exposure with increased cholesterol, changes in liver enzymes, lower antibody response to some vaccines, pregnancy-induced hypertension and preeclampsia, small decreases in birth weight, and kidney and testicular cancer (the cancer link is for PFOA specifically).

Same story with metals. The Lead and Copper Rule Improvements, finalized in October 2024, require most systems to replace lead service lines on a defined timeline and lower the lead action level from 15 µg/L to 10 µg/L.

Same story with plastics. California adopted a regulatory definition of microplastics in drinking water in June 2020, standardized test methods in 2021–2022, and four years of required testing — as far as I can tell, the first effort of its kind by any state. WHO's 2019 review, meanwhile, found that "conventional treatment, when optimized to produce treated water of low turbidity, can remove particles smaller than a micrometre", while calling for more research into the health implications.

Why I bring up the 1.7 billion at all

Because it keeps me honest about what I'm selling.

I'm not selling survival. I'm not the difference between your team getting sick and not getting sick. Madison-area municipal water is treated, tested, and reported on, and the microbiological problem that kills people globally is not the problem I'm solving.

What I'm selling is the chemistry layer. Point-of-use filtration that handles the slow stuff after the utility has handled the fast stuff, plus the part nobody writes regulations about — in my experience, people drink more water when it's cold, filtered, and a few steps from their desk instead of warm from a plastic bottle in a supply closet.

That's a real value. It's just a smaller one than the marketing in my industry usually implies.

The uncomfortable version: we're arguing about parts per trillion because we already won the argument about parts per million. That's an enormous privilege. It's also not a reason to stop — decreased vaccine response in children is still decreased vaccine response in children.

Both things are true. Your water is among the safest in human history, and it still has stuff in it the government only started regulating nationally in 2024.