What Is a Lead Service Line?

A service line is the pipe that physically connects a building to the water main running under the street. Water travels through it before it ever reaches a home's internal plumbing. A lead service line means that pipe itself — not just the fixtures inside the house — is made of lead.

Why so many older cities have them

Lead was a common choice for service lines for most of the late 1800s and early-to-mid 1900s — it's soft, easy to bend around obstacles underground, and resists corrosion in a way that made it seem practical at the time. Cities with a lot of housing built before that era, especially in the Northeast and Midwest, tend to have the most lead lines still in the ground today.

Congress banned the installation of new lead pipes and lead solder in 1986, through an amendment to the Safe Drinking Water Act (enforcement varied somewhat by state, with some states not fully applying it until 1988). A line installed before that point could still be lead; anything installed correctly after it should not be.

Two sides, two owners

A service line usually has two segments, and this matters because they're often owned — and replaced — separately:

• The utility-owned (public) side — from the water main to roughly the property line or curb stop. The water utility is generally responsible for this segment.
• The customer-owned (private) side — from that point into the building. The property owner is generally responsible for this segment, which is part of why full lead pipe replacement is often more complicated (and more expensive) than it sounds — a utility replacing its own side doesn't necessarily replace the homeowner's side too, and a "partial replacement" can temporarily increase lead levels before they improve.

What about "galvanized requiring replacement"?

Galvanized steel pipe isn't lead itself, but if it was ever installed downstream of a lead gooseneck, connector, or lead service line, it can absorb and later release lead particles that got trapped in its rough interior surface over the years — even after the original lead pipe is gone. Federal guidance treats this category with the same urgency as a confirmed lead line for exactly that reason.

Why this is being tracked now

The EPA's Lead and Copper Rule Revisions required every public water system in the country to compile a full inventory of its service lines and make it publicly available by October 2024. That inventory — for New York State and, separately, New York City — is the actual source of every result on this site.