7 Warning Signs Your Tap Water May Be Contaminated

Your senses catch some water problems and miss the worst ones entirely. Here's how to read the signals your tap gives you — and the crucial caveat at the end.

The seven signals

• **Cloudiness that doesn't clear.** Bubbles that settle in seconds are harmless dissolved air. Haze that persists can be sediment or, rarely, microbial growth — worth a test.
• **Brown, orange or yellow tint.** Usually iron or rust from aging pipes or water-main work. Unpleasant more than dangerous, but persistent discoloration means pipes are corroding — and corroding pipes can also shed lead.
• **Rotten-egg smell.** Hydrogen sulfide, common in well water. Mostly a nuisance, but it can indicate sulfur bacteria in the well or water heater.
• **Strong chlorine smell.** Utilities chlorinate on purpose; a sudden spike often follows main repairs. Chronic strong chlorine taste is fixable with a simple carbon filter.
• **Metallic taste.** Often iron, zinc or low pH. Note carefully: lead has no taste — a clean-tasting glass proves nothing about lead.
• **Blue-green stains on fixtures.** Classic copper corrosion, often from acidic water — the same conditions that leach lead from old solder.
• **Repeated unexplained stomach issues in the household.** Especially on well water, this justifies an immediate bacteria test.

The caveat that matters most

Lead, PFAS, nitrates and arsenic — the contaminants with the most serious health evidence — are invisible, tasteless and odorless at harmful levels. Perfect-looking water can fail a lab test, and ugly water can pass one. Signals tell you when to hurry; only testing tells you the answer. Start with your state's quality data, then confirm with a certified test.