Skip to content

Lead Service Lines in Washington

The Washington headline is how much is still unknown. Enter your ZIP below to see the water systems serving your county and exactly what each one told EPA its service lines are made of. Every figure here is EPA's, from the April to June 2026 extract, and each one is a utility's count for its whole network.

Washington utilities have not established the material of 220,180 service lines, 10.2 percent of everything they reported
Reported as lead
237
Galvanized needing replacement
6,685
Material still unknown
220,180
Systems reporting nothing
548

These are counts of pipe a utility reported, for its whole network, not a finding about any address. The record for your own service line is your utility's inventory for your address.

Look up the water systems serving your ZIP

Enter a Washington ZIP code. You get every community water system EPA lists for the county or countys that ZIP touches, and for each one, the service line materials it reported in EPA's four categories, its most recent listed lead tap result, and the doors to its own records.

What Washington utilities actually reported

Washington reported 237 lead service lines, but 23.7 percent of its 2,311 community systems reported no service line types at all, the second largest reporting gap of any state. Only 10.2 percent of the lines that were reported are unknown, so Washington's picture is unusually split: the utilities that answered answered well, and a quarter of them did not answer.

A water service line exposed in an excavation, the pipe running from the main to a building

Across 2,311 active community water systems, Washington reported 2,167,162 service lines in total: 237 lead, 6,685 galvanized requiring replacement, 220,180 of unknown material and 1,940,060 non lead. That puts it 33 of 50 states by confirmed lead plus galvanized lines, and 27 of 50 by the raw size of its unknown column.

548 of those systems, 23.7 percent of the state, reported no service line types at all. Those systems are blanks in the federal record rather than systems with nothing to report, and they are excluded from the totals above rather than counted as zero. 1,105 systems, 47.8 percent, report that every line they own has been identified.

Our summary of information published by EPA SDWIS service line inventory report

This page leads with the unknown column because in Washington 10.2 percent of reported lines have no established material (the cut is 30 percent) or 23.7 percent of systems reported nothing (the cut is 15 percent). With that much of the record unresolved, the confirmed counts are partial by construction, so the unknown column is the finding.

EPA separately PROJECTS 1,437 lead service lines and 6,545 galvanized requiring replacement in Washington, about 7,982 together, for the purpose of allocating federal replacement money. That is a larger number than the 6,922 reported above, and the difference is the unknowns: EPA distributes a share of each state's unknown lines into the lead column using that state's own ratio of lead to identified pipe. It is a funding estimate rather than a count, and it is shown separately from the reported counts throughout.

Our summary of information published by EPA 7th Drinking Water Infrastructure Needs Survey and Assessment

EPA's four categories, and what they mean

Every inventory in the country sorts lines into the same four buckets. The one people misread is the last: unknown is not a finding of no lead, and in Washington it covers 220,180 lines.

  • Lead status unknown

    The utility has not established what this line is made of. It is not a finding of lead and it is not a finding of no lead.

    220,180
  • Lead

    The utility records this line as lead.

    237
  • Galvanized requiring replacement

    Galvanized iron or steel that sits, or once sat, downstream of a lead line, so it can hold lead picked up from it. The rule treats it like lead.

    6,685
  • Non lead

    The utility records this line as something other than lead or galvanized requiring replacement, most often copper or plastic.

    1,940,060

“A GRR service line is a galvanized service line that currently is or ever was downstream of an LSL or is currently downstream of a service line of unknown material.”

US EPA, Final Lead and Copper Rule Improvements technical fact sheet

Galvanized requiring replacement is the category that surprises people, because the pipe is not lead. It is galvanized iron or steel whose rough interior can hold lead that washed down from a lead line upstream, and it keeps releasing it after the lead is gone, which is why the rule treats it the same way.

Water supply pipes running inside a building wall, the plumbing an inventory does not cover

Where the inventory stops

A service line is the pipe between the water main and the building. The inventory covers that and nothing else: not the plumbing inside the walls, not the solder in its joints, not the fixtures on the end of it. Lead solder was legal in household plumbing until 1986 and brass fittings could legally contain lead long after that.

“Among homes without lead service lines, the most common problem is with brass or chrome-plated brass faucets and plumbing with lead solder.”

US EPA, Basic Information about Lead in Drinking Water

This is the utility's record, not a test of your home. An inventory is what a water system believes about the pipe between its main and a building, assembled from permits, tap cards and spot checks. It can be wrong, it is counted at the system level here, and across the country the largest category in it is lead status unknown. It says nothing about the plumbing inside your walls: EPA notes that “Among homes without lead service lines, the most common problem is with brass or chrome-plated brass faucets and plumbing with lead solder.” Your utility's own inventory for your address, and a laboratory test of your own tap, are the two records that speak to a particular home; no public dataset does.

What the federal rule requires, and by when

Two EPA rules govern this: the Lead and Copper Rule Revisions, which created the inventory, and the Lead and Copper Rule Improvements, which extended it and set the replacement clock.

“All systems must develop an initial lead service line (LSL) inventory by October 16, 2024, that includes all service lines, regardless of ownership, categorized as lead, non-lead, galvanized requiring replacement (GRR), and unknown.”

US EPA, Lead and Copper Rule Improvements comparison table
  • October 16, 2024The first deadline. Every community and non transient non community water system had to have compiled an initial service line inventory covering every line it serves, in EPA's four categories.
  • Since thenSystems must notify anyone served by a line recorded as lead, as galvanized requiring replacement, or as unknown. A letter saying "unknown" is the rule working, not a finding about the building.
  • November 1, 2027The baseline inventory is due: an updated version that adds connectors and validates the non lead category, so a line called non lead has to be backed by something.
  • Then ten yearsFull replacement of lead and galvanized requiring replacement lines under the system's control, with limited exceptions, whatever the system's 90th percentile lead level.

Did Washington systems file?

No Washington system carries a listed LSL Inventory violation in EPA's compliance file, so on the federal record the state's utilities filed what they owed. Read this as paperwork rather than pipe. A system with no violation filed something, which says nothing at all about what the something said, and states differ enormously in how thoroughly they report enforcement to EPA.

“Compliance statistics are based on violations reported by states to the EPA Safe Drinking Water Information System (SDWIS). EPA is aware of inaccuracies and underreporting of some data in this system. We are working with the states to improve the quality of the data.”

US EPA ECHO, Drinking Water (SDWA) FAQs

Finding your own system's inventory

“The inventory must be made publicly accessible and available online for systems serving > 50,000 persons.”

US EPA, Lead and Copper Rule Improvements comparison table

Washington by county

What the systems serving each county reported. Sorted by lead and galvanized lines, then by unknowns.

Loading the county table from the committed EPA snapshot.

The other federal record: lead at the tap

Separately from the inventory, systems sample tap water at a targeted pool of higher risk homes and report a 90th percentile lead result. It measures water, not pipe, and the two records answer different questions.

In Washington, 2,142 community water systems have a lead result from a monitoring period ending within five years of the April to June 2026 extract. The median of those results is 1 parts per billion, and 19 systems sit at or above EPA's 15 parts per billion action level. A further 95 systems have no listed result newer than five years, so for those the federal record is simply old rather than reassuring.

The action level is not a health threshold. It is the concentration at which the rule requires a system to act, and EPA's replacement requirement applies whatever a system's 90th percentile is. A system can report a low percentile and still have thousands of lead lines in the ground.

Our summary of information published by EPA ECHO Safe Drinking Water Act data

“EPA and the Centers for Disease Control and Prevention (CDC) agree that there is no known safe level of lead in a child’s blood.”

US EPA, Basic Information about Lead in Drinking Water

CDC publishes guidance on lead in drinking water and on blood lead testing for children, linked here: CDC Lead in Drinking Water. EPA's own household checklist is EPA Protect Your Tap, a quick check for lead.

Washington lead service line questions