A lead pipe is a plumbing pipe made from lead metal, used for over a century to carry drinking water from public water mains into homes. Lead is a soft, bluish-white metal that was favored for plumbing because it resists corrosion, bends easily, and has a low melting point, making it simple to shape and install. Millions of these pipes remain in use across the United States today, even though they can leach harmful amounts of lead into drinking water.
Why Lead Was Used in Plumbing
Lead’s physical properties made it an almost ideal pipe material before its health risks were understood. It’s extremely malleable, meaning plumbers could bend and shape it by hand to fit tight spaces. It’s dense (about 11 times heavier than water) and highly resistant to the kind of chemical wear that breaks down other metals over time. Its melting point of roughly 327°C (621°F) meant it could be melted and joined with relatively simple tools. The word “plumbing” itself comes from the Latin word for lead, “plumbum.”
Lead pipes were standard in American construction for decades. National plumbing codes permitted lead for water service lines until the late 1970s in some regions and as late as 1988 under the Uniform Plumbing Code. In 1986, Congress amended the Safe Drinking Water Act to prohibit lead pipes, solder, or flux in any plumbing connected to public water systems or providing water for human consumption. But that ban only applied to new installations. Homes built before the late 1980s may still have lead service lines connecting them to the water main, lead solder at pipe joints, or both.
How Lead Gets Into Drinking Water
Lead doesn’t dissolve into water all at once. It enters gradually through corrosion, a chemical reaction between the water flowing through the pipe and the lead metal itself. Several factors control how much lead ends up in your water. Acidic water or water with low mineral content is more aggressive, corroding pipes faster. Warmer water dissolves more lead than cold water. And the longer water sits motionless inside a lead pipe (overnight, for example, or during a vacation), the more lead it absorbs.
Over time, some lead pipes develop a thin mineral coating on the inside that acts as a partial barrier between the metal and the water. Water utilities sometimes add chemicals to encourage this coating to form, a process called corrosion control. But this protective layer isn’t foolproof. Changes in water chemistry, construction that jostles the pipe, or even a switch in the water source can disturb the coating and cause a sudden spike in lead levels. This is essentially what happened during the Flint, Michigan water crisis.
It’s also worth knowing that lead contamination isn’t limited to lead pipes alone. Galvanized steel pipes, which are coated in zinc, can trap lead particles on their interior surface over years of use. Even after a lead pipe is removed, a downstream galvanized pipe can continue releasing stored lead into your water for some time.
Health Risks of Lead Exposure
There is no safe level of lead exposure, particularly for children. Lead that enters the body through drinking water is absorbed into the bloodstream, where it can damage the brain and nervous system, slow growth and development, and cause learning and behavior problems. Children exposed to lead may experience lower IQ scores, difficulty paying attention, and hearing and speech problems. Even low levels of lead in blood have been shown to negatively affect a child’s health.
Once lead enters the body, it doesn’t leave quickly. Some of it is excreted through urine and sweat, but a significant portion is stored in bones, where it can remain for decades. Adults exposed to lead can develop high blood pressure, kidney damage, and reproductive problems, though children are far more vulnerable because their developing brains absorb lead more readily.
How to Tell if You Have Lead Pipes
You can check your own service line with two simple tests. First, find where your water line enters your home, usually in the basement or crawl space near the water meter. Look at the pipe’s color: lead pipes are a dull gray or silver. Copper is distinctly reddish-brown (sometimes with green discoloration), and galvanized steel is also gray but often shows rust.
Next, try the scratch test. Use a house key or coin to scratch the surface of the pipe. If it’s lead, the metal will scratch very easily and reveal a shiny silver color underneath. Galvanized steel is much harder to scratch. You can also hold a strong magnet to the pipe. Lead is not magnetic, so if the magnet sticks, you have galvanized steel. Copper is also non-magnetic, but its color makes it easy to distinguish from lead.
Keep in mind that even if the visible pipes inside your home are copper, the service line running underground from the water main to your house could still be lead. Many homes have a mix of materials installed at different times.
Current Regulations and Replacement Efforts
The EPA regulates lead in drinking water through the Lead and Copper Rule. In 2024, the agency finalized improvements to this rule, lowering the threshold for action from 15 parts per billion to 10 parts per billion. Water utilities were required to complete initial inventories of lead service lines by October 2024 and must update those inventories on a regular basis going forward.
Full replacement of a lead service line, meaning the entire pipe from the water main to the home, is the only permanent solution. The EPA estimates an average cost of $4,700, though the range spans from $1,200 to $12,300 depending on factors like pipe depth, length, and local labor costs. Partial replacement, where only the utility-owned portion of the pipe is swapped out, can actually make things worse by disturbing the pipe and temporarily increasing lead levels in the water.
Reducing Lead Exposure at Home
If you suspect you have lead pipes but can’t replace them immediately, a few practical steps can lower your exposure. Running cold water for 30 seconds to two minutes before using it for drinking or cooking flushes out water that has been sitting in contact with lead. Always use cold water for cooking and preparing baby formula, since hot water pulls more lead from pipes.
Water filters certified to NSF/ANSI Standard 53 for lead reduction are effective at removing lead. Look for the certification mark on the packaging along with a specific claim of lead reduction. Filters tested to reduce lead to 5 parts per billion or less provide the highest level of protection. For additional safety, choose a filter also certified to NSF/ANSI Standard 42 for particulate reduction (Class I), which catches tiny lead particles that dissolved-lead filters might miss. Pitcher filters, faucet-mounted filters, and under-sink systems are all available with these certifications, but they must be replaced on schedule to remain effective.