A service line is the pipe connecting the water main to your building. NYC's records show 117,561 confirmed lead service lines, plus 114,473 marked "Lead Status Unknown." The material of any building's line is a public record you can check by address.

The water in your glass made its last leg of the journey through a single pipe: the service line, running from the water main under the street into your building. What that pipe is made of was decided decades ago, mostly before anyone thought to write it down carefully, and whether anyone has checked since is, itself, now a public record.

Here's the citywide ledger. 117,561 service lines are confirmed lead in the city's records. Another 114,473 carry the official status "Lead Status Unknown," the record's way of saying nobody has verified what's down there. And 3,050 more are galvanized lines flagged as requiring replacement, because galvanized pipe downstream of lead can accumulate and re-release it. Add it up and roughly a quarter-million buildings sit somewhere between "confirmed problem" and "confirmed question mark."

Some context so the number lands correctly rather than alarmingly. NYC's source water is famously good, and the city treats it to reduce corrosion, the mechanism by which lead gets from pipe into water. A lead service line is not a guarantee of lead in your glass. It is an exposure pathway, the single largest one in the plumbing, and the reason both the city and federal rules now push toward replacing these lines entirely. "Confirmed lead" means the pathway exists. "Unknown" means it hasn't been ruled out.

What a renter does with this, in three steps:

  1. Check the line. The material status for any address is public (confirmed lead, unknown, or non-lead) and takes seconds to look up.
  2. If it's lead or unknown and you want certainty: the city offers free residential lead water-testing kits; running cold water before use after long stagnation (overnight, a vacation) is the standard interim practice for lead-line buildings, and it costs nothing.
  3. With infants or young children in the home, treat this check as non-optional, alongside the lead-paint record – the two exposures share their victims.

A VeriCrib report reads the service-line record with the rest of the building's file. Of everything in a building's record, this is the one that was hardest to know about for a century. Now it takes ten seconds. Spend the ten seconds.