Lead in Tap Water: How to Test It, and Why the Number to Beat Is Zero, Not 15 ppb

Under EPA drinking water standards, 15 ppb is an action level that triggers corrosion-control steps for a whole water system when more than 10% of sampled customer taps go over it. EPA’s maximum contaminant level goal for lead is zero. This guide shows you how to find out whether your home has a lead service line, get a test you can rely on, read the result correctly, and reduce exposure while you wait.

How lead gets into your tap water

In most cases the lead does not come from the river or aquifer that supplies your water. CDC says lead gets into drinking water through corrosion, which is metal dissolving or wearing away from pipes and fixtures. The reaction is stronger when water is more acidic or has low mineral content. The usual sources are lead pipes, faucets, and plumbing fixtures. Homes without a lead service line can still have brass faucets, galvanized iron pipes or plumbing soldered with lead.

The service line is often the biggest concern. It is the section of pipe that connects your home to the main water line, and lead can leach from it into your tap. That is why EPA describes finding and replacing these lines as an important way to cut exposure.

Step by step: from “Do I have lead?” to a result you can trust

Under the Lead and Copper Rule Revisions, water systems had to prepare and maintain an inventory of service line materials by October 16, 2024. They also had to notify customers who have a known or potential lead service line. Your utility should already have a record for your address, so call and ask.

EPA’s Protect Your Tap: A Quick Check for Lead is an online step-by-step guide for spotting lead service lines at home. Find where the water line comes into the house and follow the guide’s checks. A common problem is a pipe that is painted, wrapped, or partly buried. If you can’t tell what it’s made of, write down “unsure” and test anyway.

CDC says your local water authority is always your first source for testing, and many public water systems will test on request. If yours won’t, use a laboratory certified to test for lead in water. Protect Your Tap includes information on certified laboratories.

Results can vary with time of day, season, sampling method, and water flow. If you record these details, you can compare a second test with the first. Copy this log for each sample:

Sample date and time:
Hours the water sat unused before sampling:
Tap used (e.g., kitchen, cold side):
First draw, or after running the water?:
Recent plumbing, street, or water main work:
Lab name and certification:
Lead result (ppb):

Is a result under 15 ppb safe?

Not for the purpose you might think. EPA first issued the Lead and Copper Rule in 1991, and it uses 15 ppb to decide when a water system has to act. If more than 10% of sampled taps exceed it, the system must take additional actions to control corrosion. It must also tell the public how to protect their health and may have to replace lead service lines under its control.

For your household, the number that matters is the health goal of zero. CDC says no safe blood lead level has been identified for young children. EPA adds that children six years old and younger are most susceptible and that even low blood lead levels have harmful, irreversible effects. If small children live in the home, any lead you can detect is worth acting on. Formula-fed babies need extra care. They drink a lot of water for their body size, so formula made with lead-contaminated tap water can put them at higher risk.

What to do while you wait for results or a pipe replacement

• Use only cold water for drinking, cooking, and baby formula. CDC warns that warm or hot tap water can have higher levels of lead.
• Don’t boil water to remove lead. Boiling will not reduce the amount of lead.
• Choose a point-of-use filter by its certification, not its marketing. CDC says to look for NSF/ANSI 53 for lead removal and NSF/ANSI 42 for particulate removal. If you have a lead service line, filter the water you use for drinking and cooking.
• Keep bathing normally. Human skin does not absorb lead in water, so showers and baths are fine.
• Use bottled water if you need a stopgap. Bottled water certified by an independent testing organization can virtually eliminate exposure, but CDC notes it may not be cost-effective over the long term.

Many people run the tap before drinking from it, but the CDC and EPA material cited here doesn’t give a flushing time. Ask your utility what it recommends.

Lead service line replacement: plan for six riskier months

Replacing a lead line is the long-term fix, but it raises your risk for a while. CDC warns that exposure risk increases during the work and for up to six months afterward. That includes when the city replaces the water main on your street. Use a certified filter for the whole period, and test again once it’s over.

Ask your utility whether there are programs to help remove the lead service line going to your home. More help may be coming. EPA says it is combining its rules with funding through the Infrastructure Investment and Jobs Act. The 2024 Lead and Copper Rule Improvements aim at more and complete lead service line replacements. They also require systems to identify lead service line locations and make them public.

Sources

• cdc.gov – “About Lead in Drinking Water | Childhood Lead Poisoning Prevention | CDC” (2025)
• epa.gov – “Revised Lead and Copper Rule | US EPA” (2020)
• epa.gov – “Protect Your Tap: A Quick Check for Lead | US EPA” (2021)
• epa.gov – “Lead and Copper Rule | US EPA” (2015)