Where lead in tap water comes from
Lead rarely comes from the water source itself. It enters when plumbing that contains lead corrodes. Corrosion is worse in water that is acidic or low in minerals.
- Lead service lines: The pipe from the water main to your home. Where one exists, it is usually the biggest source.
- Solder and fittings: Fixtures, solder and fittings made before 1986 may contain lead.
- Faucets and galvanized pipe: Brass or chrome-plated brass faucets and old galvanized iron pipe can also add lead.
Because the lead is picked up between the street and your faucet, a filter at the tap is the right place to stop it.
Newer homes are not automatically lead-free. Brass faucets and fittings can still contribute small amounts. When you replace a faucet, look for a lead-free certification mark on the package.
The certification to look for
CDC recommends a point-of-use filter certified by an independent testing organization. The certification should cover two things:
- NSF/ANSI 53 for lead reduction. This is the health claim that matters.
- NSF/ANSI 42 for Class I particulate reduction. This catches tiny lead particles that break loose from pipes.
EPA's consumer guide looks for filters certified to reduce lead to 5 parts per billion (ppb) or less. Many cheap carbon filters carry only a chlorine or taste claim. Those do not count for lead.
Check the exact model in a certifier's online directory before you buy. Our page on what NSF certified means shows how to read a listing.
Filter types that work
- Certified carbon block: Comes as pitchers, faucet-mount units, countertop units and under-sink filters. It is the most common and affordable lead option.
- Reverse osmosis: RO rejects lead at the membrane. Choose one certified to NSF/ANSI 58 for lead. It also helps if you have other dissolved metals or concerns.
- Distillation: Leaves lead behind in the boiling chamber. It is slow, but effective. Look for NSF/ANSI 62.
For most homes, a certified carbon block filter at the kitchen tap is enough. Pick RO if you also need to reduce something carbon does not handle, like nitrate or arsenic.
Size matters, too. Pitchers are easy but hold little media, so cartridges run out quickly. Faucet-mount and under-sink units treat more water between changes. Whatever you choose, install it where you fill glasses and pots.
| Process | Works for lead? | Certification to look for | Best for |
|---|---|---|---|
| Carbon block | Yes, if certified | NSF/ANSI 53 (lead) + NSF/ANSI 42 (Class I particulate) | Most homes; pitchers, faucet-mount, under-sink |
| Reverse osmosis | Yes | NSF/ANSI 58 (lead reduction) | Homes with more than one concern |
| Distillation | Yes | NSF/ANSI 62 | Small volumes on a countertop |
| Water softener | No | None for lead | Hardness only |
| Boiling | No | None | Not a lead fix |
What does not remove lead
- Boiling: CDC says boiling will not reduce lead in water.
- Water softeners: A softener is not a lead treatment. Don't rely on one. See softener vs. filter for the difference.
- Uncertified filters: Without an NSF/ANSI 53 lead claim, you don't know what a filter does.
- Expired cartridges: A filter past its rated capacity may no longer reduce lead. Replace it on schedule.
Lead rules and what they mean for you
EPA's health goal for lead in drinking water is zero. CDC and EPA agree no safe blood lead level has been identified in children.
Utilities must act when more than 10 percent of tested homes exceed the lead action level. Today that level is 15 ppb. Under the Lead and Copper Rule Improvements, it drops to 10 ppb starting November 1, 2027. Most water systems must also replace lead service lines within 10 years of that date.
An action level is a trigger for utility action, not a safe limit. That is why a certified filter makes sense in homes with lead pipes or older fixtures.
Your utility's annual water quality report shows recent lead sampling results. It is a good place to start, but it reflects many homes, not just yours.
Simple habits and testing
- Use cold water for drinking, cooking and baby formula. Warm or hot tap water can carry more lead.
- Ask your utility whether your home has a lead service line. Many will test your water on request, or you can use a certified lab.
- Expect variation. Lead results change with time of day, season and how long water sat in the pipes.
- Plan for construction. Lead can rise during service line or main replacement, and for up to six months after. Keep using a filter during that time.
Bathing and showering are considered safe, because skin does not absorb lead from water.
Infants fed formula made with tap water may face higher risk. They drink a lot relative to their body size. If you are worried about exposure, talk to your child's doctor. A blood lead test is the best way to find out.