To tell if a pipe is lead, find where your water line enters the house and do the EPA's two checks: scratch it gently with a key, then hold a magnet to it. Shiny silver and not magnetic suggests lead. Phoenix customers can also check the city's service line map; the city has found no lead lines since 2021.
Where do you look for a lead pipe?
The pipe that matters most is the service line, the buried pipe between the water main and your house. The EPA says that in homes with lead service lines, "these pipes are typically the most significant source of lead in the water."
The EPA's customer guide tells you to find the water meter first, then follow the line to where it enters the building. If the meter is outside, the service line most likely enters the house at the point closest to the meter. Phoenix describes a full service line as running from the city meter box to the hose bib or connection at the house, so that connection is where you test. If you can't see any exposed pipe, the EPA guide says to contact your water system for guidance.
Inside the house, lead is less likely to be a whole pipe. The EPA notes that among homes without lead service lines, "the most common problem is with brass or chrome-plated brass faucets and plumbing with lead solder."
How do you do the scratch and magnet test?
Gently scratch the pipe near where it comes through the wall or out of the ground, then set a magnet on it. The EPA guide reads the results like this:
| What you see | Magnet | Likely material |
|---|---|---|
| Shiny silver where you scratched | Does not stick | Lead |
| Penny color under a green to dark brown film | Does not stick | Copper |
| Silver or gray, hard to scratch | Sticks | Galvanized iron or steel |
| White, gray or another color, no metal | n/a | Plastic |
Scratch lightly. You only need a fresh line, not a gouge. If the pipe is plastic, the EPA guide notes that lead may still be present in other parts of the plumbing, such as faucets and solder. Our page on telling the age and condition of home plumbing covers the rest of the pipe types you may find.
What does Phoenix's service line inventory show?
Phoenix has looked hard for lead, and here's what it reports on its lead service line site:
- No lead found so far. Since starting field investigations in 2021, the city says it has not found any lead lines.
- Old rules ended lead early. The city's standards discontinued all-lead service lines in 1938, and a city ordinance banned lead water pipes and fittings in 1977. Galvanized service lines were discontinued in 1983.
- The inventory is public. The city says it published its inventory with ADEQ in October 2024, and you can view your own service line on its interactive map.
- Unknown does not mean lead. The city says "Service lines marked as unknown are unlikely to be lead."
The bigger Phoenix issue is galvanized lines. The city explains that galvanized service lines can pose a health risk because the zinc coating corrodes over time, potentially leaching lead particles. When a line is identified as galvanized, Phoenix says it will contact you about replacement, and for those lines, "The City covers the entire cost of this service line replacement work." Our page on whether your main water line needs replacing explains that program in more detail.
Not on City of Phoenix water? The EPA's advice is to ask your water utility whether your service line is lead, and to ask what material it has on file for your address.
What should you do if you think you have lead?
Act on two tracks: cut your exposure now, and confirm what you have. It is worth the effort: the EPA estimates that drinking water can make up 20 percent or more of a person's total exposure to lead.
Cut exposure today. These steps come from the EPA and the City of Phoenix:
- 1Run the water before drinking if it has sat for hours. The EPA says the more time water sits in pipes, the more lead it may contain. You can flush by running the tap, showering, or running a load of laundry or dishes.
- 2Use cold water for drinking, cooking and baby formula. Phoenix adds that boiling water does not remove lead.
- 3Use a filter certified to remove lead, as Phoenix recommends, until you know more.
Confirm it. A visual check tells you about the pipe, not the water. A lab test is the only way to know if lead is in what comes out of the tap. Our step-by-step guide on how to test your home's water for lead covers first-draw samples and certified Arizona labs.
Report it. Tell your water utility what you found. In Phoenix, the city says that if a lead line is identified, it will contact you about replacement.
When do you need a plumber?
Call a licensed plumber when the pipe on your side of the meter, or any pipe inside the house, needs replacing. The EPA also says that if your utility doesn't have information on your service line, "a licensed plumber may be able to assist." Replacing a galvanized or suspect line, or swapping old brass fixtures for certified lead-free ones, is plumbing work. Our note on NSF 61 and NSF 372 lead-free valves explains the marks to look for on replacement parts.
HQ Plumbing & Air handles residential water line and repipe work across the Valley. We're licensed and insured, we give free estimates, and we'll show you what your pipe is made of before anyone talks about replacing it.