Short definition
Lead pipe — most often a lead service line (LSL) — is soft lead piping used widely for buried water-service connections in pre-WWII US construction. It’s a known drinking-water lead source and was banned for new potable installations under the 1986 Safe Drinking Water Act amendments. Active replacement is underway in Tacoma, Seattle, and other Washington utilities under the EPA’s 2024 Lead and Copper Rule Improvements.
What it is
Lead is soft, easily bent, and mechanically durable — which is why it was used as a service-line material before its health risks were widely understood. Pre-1945 Seattle and Tacoma homes were commonly connected via either a full lead service line or a lead service loop (also called a lead pigtail) — a soft lead U-bend joining the city main tap to the galvanized service line, providing flexibility for soil settlement.
Even in homes without lead pipe, lead solder on copper joints was the residential standard until 1986. That means pre-1988 plumbing in any Washington home — regardless of service-line material — likely has lead-solder joints contributing to household lead exposure.
The federal “lead-free” definition under the 2011 SDWA amendment requires not more than 0.25% lead averaged on wetted surfaces of pipes, fittings, and fixtures, and not more than 0.2% in solder or flux. Anything installed since then meets that standard; anything earlier may not.
Why it matters to a homeowner
If you’re in a pre-1945 Seattle or Tacoma home, the question of whether you have a lead service line is a real one. The 2024 Lead and Copper Rule Improvements require public water systems to maintain a lead-service-line inventory and complete replacements over a ten-year window. You can ask your utility whether your address is on the LSL inventory, and if so, what the replacement timing is.
Practical points if you find or suspect lead in your service line or solder:
- Run cold water for 30 seconds to 2 minutes after stagnation (overnight, while at work) before drinking or cooking. Stagnant water in lead-containing pipes accumulates more dissolved lead.
- Use cold water only for cooking and infant formula. Hot water dissolves lead more readily.
- Use an NSF/ANSI 53-certified filter for lead at the kitchen tap if you’re concerned and can’t or won’t replace immediately.
- Avoid partial replacements. EPA recommends full replacement (utility-side and customer-side together) because partial replacements can spike particulate lead for weeks or months.
- Test if uncertain. A certified lab water test is inexpensive and definitive. The EPA Lead and Copper Rule action level is 15 ppb at the tap.
Washington note
Two WA-specific points:
- Tacoma Water ran an active lead-gooseneck removal program from 2016 to 2021, ultimately removing 342 lead goosenecks from 1,215 candidate connections. By 2021, all known utility-side lead service connections had been removed. The remaining concern is private-side service lines on pre-1986 homes and lead-solder joints inside the home.
- Seattle Public Utilities is also conducting an LSL inventory under the LCRI mandate. Specific replacement progress and customer-side cost share vary; check SPU’s current Lead and Copper page for your address.
- Spokane Water Department completed all known utility-side lead service line removals in 2018.
In all three cities, the residual household-side concern is pre-1988 lead-solder joints in the original copper distribution piping — that’s an inside-home issue regardless of utility-side service-line status.
Common failure modes
- Lead leaching into water at varying rates depending on water chemistry — elevated where water is soft and acidic (Cedar/Tolt SPU water profile, aggressive private-well water).
- Particulate lead release after physical disturbance (utility work, partial replacement) — can spike levels for weeks.
- Lead solder on otherwise-non-lead service lines — the inside-home component of the lead-exposure picture.