Your Water: What's in It and What to Do About It
Most people don’t know what’s in their water until something goes wrong. A weird smell. A neighbor’s test comes back with lead. A news story about PFAS contamination two towns over.
This section covers what’s actually in drinking water, both the regulated stuff utilities are required to test for, and the gaps in that testing.
City Water vs. Well Water
The EPA’s Safe Drinking Water Act covers about 90 contaminants. Your utility must test for them all, report violations within 30 days, and send you an annual Consumer Confidence Report (CCR). You can look yours up at EPA’s CCR database.
The rules cover municipal systems serving 25 or more people. Private wells fall outside EPA jurisdiction entirely.
That matters because roughly 43 million Americans use private wells, according to the 2017 CDC report. If you’re one of them, you’re responsible for testing. No agency will remind you.
What the EPA Doesn’t Regulate
Being legal doesn’t mean being safe. A few examples:
The EPA sets a “maximum contaminant level” (MCL) of 15 parts per billion (ppb) for lead. But the EPA itself says there is no safe level of lead exposure in children. The 15 ppb limit is a practical treatment standard, not a health threshold.
PFAS, a group of thousands of synthetic chemicals used in nonstick cookware, firefighting foam, and waterproof clothing, went essentially unregulated in drinking water until April 2024. The EPA’s new MCL for PFOA and PFOS is 4 parts per trillion. Many utilities are still working to comply.
Disinfection byproducts form when chlorine or chloramine reacts with organic matter in source water. The EPA limits trihalomethanes (THMs) at 80 ppb. Some research links long-term THM exposure to bladder cancer risk, though the absolute risk is small.
The Contaminants That Matter Most
These are the four we hear about most often, and the ones with the best evidence behind the concern.
Lead, no safe level in children. Primary source: old lead pipes and lead-solder plumbing, not usually the treatment plant. Renters and owners of pre-1986 homes should test.
PFAS, detected in roughly 45% of US tap water samples, per a 2023 USGS study. Linked to thyroid disease, kidney cancer, and immune suppression at elevated exposures. Reverse osmosis removes 90, 99%.
Nitrates, a health risk for infants under six months. Common in well water near agricultural land. The EPA MCL is 10 mg/L. Any level above that is a problem for formula-fed babies.
Hard water, calcium and magnesium dissolved in water. Not a health risk. Does shorten water heater and appliance life significantly. A water softener solves it, but adds sodium to the water in exchange.
Start with a Symptom
If something about your water seems off, start here. Each of these pages diagnoses a specific symptom and tells you what to test for.
- Brown water from your tap, main break, iron, or sediment
- Metallic taste in water, iron, copper, zinc, or lead (test before assuming)
- Orange stains in toilet, sink, or tub, iron in your water supply
- Hot water smells like rotten eggs, water heater anode rod (not usually the well)
- Water tastes like chlorine, municipal disinfection, usually fixable with carbon
- White residue on dishes, hard water (calcium and magnesium scale)
- Blue-green stains around faucets, copper pipe corrosion from low-pH water
- Musty or earthy smell in water, bacteria, algae, or decaying organic matter
- Water feels slippery after softener, that’s the softener working, not a problem
Where to Start
Get a water test before buying any filter. A test tells you what’s actually present, not what might be. An at-home test kit covers the basics quickly. A mail-in lab test gives you more detail and a written report.
From there, treatment is specific to the problem. RO for PFAS and lead. A water softener for hardness. An iron filter for well water with iron issues. There’s no single filter that handles everything.