What's Actually in Your Tap Water? A Family-Friendly Breakdown

Most parents assume that if water comes out of the tap, it's been thoroughly screened. The truth is more complicated. Federal rules require utilities to test for about 90 contaminants and stay under specific limits, but those limits were set decades ago — and there are dozens of substances showing up in modern water that aren't on the list at all.

What your utility actually tests for

Public water systems test for things like coliform bacteria, lead and copper at the tap, disinfection byproducts, and a handful of regulated chemicals like nitrate, arsenic, and atrazine. The full list of regulated contaminants is published by the EPA, and your local Consumer Confidence Report (CCR) will tell you what was detected last year.

What they don't test for

This is where it gets interesting. Common gaps include:

• PFAS (forever chemicals) — only recently regulated and rarely tested at the tap

• Microplastics — not regulated at all in U.S. drinking water

• Pharmaceutical residues — detected in many sources, not on the EPA list

• Lead from your home's plumbing — utilities test at the source, not your faucet

What to test at home

If you live in a home built before 1986, lead is the single most important contaminant to rule out. After that, PFAS and nitrates are worth checking — especially if you're near agricultural land or industrial zones. A comprehensive water kit will cover all three plus heavy metals like arsenic and copper.

Bottom line

Trust your utility for the basics, but verify everything that happens between their treatment plant and your kitchen tap. Your home's pipes, fixtures, and the route the water takes are not their responsibility — they're yours.