Lead in drinking water.

An estimated 4 million U.S. homes still have a lead service line. The water leaving the treatment plant is almost always fine; the lead arrives in the last 50 feet of pipe between the street and your kitchen tap.

Where lead enters tap water.

There are four lead pathways into a household water supply, all of them in the last fifty feet of plumbing. Lead service lines, the single biggest source. Lead solder at copper-pipe joints, banned in 1986 but still in every pre-1986 house. Brass faucets and shut-off valves, which could legally contain up to 8% lead until 2014. And galvanized steel pipes that absorbed lead from upstream and re-release it for decades.

EPA's 2025 update to the 7th Drinking Water Infrastructure Needs Survey projects 4 million lead service lines remain in U.S. service. EPA's Lead and Copper Rule Revisions (LCRR) required every public water utility to inventory the material of every service line in its system by October 16, 2024. That information is now public, by address, on most utility websites.

Where to look in your house.

If your home is pre-1986, assume lead is somewhere in the system until you prove otherwise. The high-risk targets:

• The service line itself — find the pipe entering your basement near the water meter
• Solder joints on copper pipe — the silvery beads where two copper pipes meet
• Brass faucet bodies and shut-off valves — particularly anything pre-2014
• Galvanized steel fittings — old galvanized can hold lead from years ago
• Hose bibs and outdoor spigots — almost always cast brass
• Pre-1980 plumbing fixtures, including refrigerator water lines
• Well systems with brass pump components or galvanized casing

How to check your service line in five minutes.

1. Find your water pipe. Basement, garage, utility closet. Look for the pipe coming up through the floor with a meter on it.
2. Look at the color. Dull gray = could be lead. Shiny orange = copper. Silver hard = galvanized. Plastic = no lead in the pipe.
3. Scratch it with a penny. Bright silver shine = lead. Bright orange = copper. No mark = galvanized or plastic.
4. For a confirmed answer, drop FluoroSpec on the scratch. Bright green glow = lead.
5. If your pipe is lead, run cold water for 30 seconds before drinking, install an NSF/ANSI 53-certified filter, and call your utility.

The full step-by-step walkthrough lives on the ZIP screener page, with photos and outcome cards.

First-draw water is the highest-lead sample.

Whenever water sits still in a lead service line, lead solder joint, or brass fixture, lead leaches into it. The morning's first draw — the water that has been sitting overnight — is consistently the most contaminated sample in any home with leaded plumbing. The fix is small and habitual: run cold water for 30 seconds before drinking or filling a bottle, every faucet, every morning.

Cold water only for cooking, drinking, and especially baby formula. Hot water leaches more lead. The 30-second flush rule is the single most effective free intervention available.

Run your ZIP. Get the picture.

The ZIP screener pulls EPA's 2025 lead service line projections, U.S. Census housing-age data, and the LCRR initial inventory framework into one number for your area, with a step-by-step walkthrough of how to check your specific pipe.