Water quality, explained
Straightforward guides to the drinking-water questions people actually ask — what the rules mean, what the data can and can’t tell you, and what to do about it.
Hard Water vs. Unsafe Water: What's the Difference
Scale on your faucet and spots on your glasses feel like a water-quality problem. But hardness and safety are two different things. Here's how to tell them apart.
July 16, 2026
How TapGraded Grades Work
The Tap Grade turns a water system's EPA record into a single A–F letter. Here's what goes into it, what it deliberately leaves out, and how to reproduce any score yourself.
July 16, 2026
Boil Water Advisory: What to Actually Do
When your utility issues a boil water advisory, the steps are simple — but there's one dangerous misconception. Here's exactly what to do, per EPA guidance.
July 15, 2026
Reverse Osmosis vs. Carbon Filters: Which Removes What
The two most common home water filters work in completely different ways and remove different things. Here's how to match the filter to the contaminant — and read the NSF certification that proves it works.
July 15, 2026
Well Water Testing 101
About 1 in 7 US households drinks from a private well — and no one tests it for you. Here's what to test for, how often, and how to find a certified lab.
July 14, 2026
Lead in Water: Action Level vs. MCL (and Why Lead Has No MCL)
Lead is the one major drinking-water contaminant with no Maximum Contaminant Level. Here's why, what the 15 ppb action level actually means, and what changes in 2027.
July 13, 2026
PFAS Drinking Water Rules, Explained (2026)
In 2024 the EPA set the first federal limits on PFAS in drinking water. In 2026 it proposed to keep some and roll back others. Here's exactly where the rules stand — and what's still in force.
July 12, 2026
How to Read Your Water Quality Report (CCR)
Every US community water system mails an annual Consumer Confidence Report. Here's what's actually in it, which numbers matter, and what it can't tell you about your own tap.
July 10, 2026