Learn About Your Tap Water

Learn how to read water reports, understand EPA standards, and make informed decisions about your tap water.

40 articles

Deep-dives on specific water contaminants including lead, PFAS, arsenic, and more. Learn about health effects and removal methods.

6 articles

NSF certification explained, filter comparisons, and expert recommendations for removing specific contaminants.

14 articles

City-specific water quality analysis, contamination issues, and local recommendations.

3 articles

Home test kits, certified lab reviews, and guidance on when and how to test your tap water.

2 articles

Softened water is safe for almost everyone to drink — an ion-exchange softener adds roughly 7.9 mg/L of sodium for every grain per gallon of hardness it removes, which in very hard water lands the finished glass near 159 mg/L, about 14% of a day's sodium. The harder question is what was in the water beforehand: every community water system in America is required by federal law to measure sodium, is held to no limit whatsoever, and is not required to tell you the answer.

Since 2018, Pennsylvania schools that tested their water had to report any detectable lead. The July 2026 budget raised that to 5 parts per billion. We pulled the state's own spreadsheet — 999 readings from 764 school buildings — and found a median of 26.6 ppb, a maximum of 8,768 ppb, and only 67 of Pennsylvania's 500 school districts reporting anything at all in seven years. Meanwhile Michigan, Indiana, and Minnesota each expanded public reporting.

Test a private well every year for total coliform bacteria and nitrate, every three to five years for the contaminants your local geology carries, and immediately after flooding, repairs, or any change in taste. That is what EPA, the CDC, and state agencies converge on — and in 47 of 51 US jurisdictions no law will ever require any of it. Priced at a state laboratory, the whole schedule costs about $70 a year.

Per gallon treated, a whole-house filter is the cheapest filtration you can buy — about $1.83 per 1,000 gallons, a fifth of what the utility charges to deliver that water. Per gallon you actually drink it is the most expensive option, because a household drinks under 1% of what it uses. Replacement cartridges, not the purchase price, are 53% to 95% of the five-year bill, and the cheapest certified path to safe drinking water is a $33 faucet-mount.

The filter type sets the ceiling; the NSF certification on the specific model is what proves it removes your contaminant. Carbon filters handle chlorine and — when NSF 53-certified — lead, PFAS, and VOCs, but they can't touch dissolved arsenic, fluoride, nitrate, or chromium-6. Those four need reverse osmosis. Match the technology to your water report, then verify the model.

Yes — treated tap water contains micro- and nanoplastics, though bottled water runs about 3× higher by particle count (Hart & Lenhart, 2025). How much is genuinely uncertain, the WHO calls it low concern at current levels, and the human health evidence is association, not proof. It's not on your CCR because there's no federal standard — only California even measures it — and reverse osmosis removes essentially all of it.