King County Water District No 90, WA
Lead detected, under the action levels
Latest 90th-percentile lead: 1.2 ppb (monitoring period 2023-2025). The federal action level is 15 ppb today and drops to 10 ppb in Nov 2027; EPA's health goal is 0. Lead was measured in sampled homes but the 90th percentile is under both action levels. EPA's health goal for lead is zero, so test your own tap if your home was built before 1986 or anyone in it is pregnant or a young child.
Who runs the water here
King County Water District No 90 serves about 20,100 people through 8,081 service connections, which makes it a large system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws surface water, in King County, Washington. EPA system ID: WA5341150. Ask the utility on your bill for your address in their service line inventory.
Every lead result on file
That is down 1.1 ppb from 2.3 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for King County Water District No 90 is 2.3 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1.2 ppb |
| 2022 | 2.3 ppb |
| 2019 | 1.2 ppb |
| 2016 | 2 ppb |
How King County Water District No 90 compares
Of the 2,218 Washington systems with a lead result, the median latest reading is 1 ppb; 18 are over 15 ppb right now and 62 have gone over at some point. King County Water District No 90's 1.2 ppb sits at the 55th percentile in Washington and the 59th nationally (higher means more lead).
Neighbouring systems
153 other systems share King County; 59 of them have a higher latest lead result than King County Water District No 90. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Seattle Public Utilities | 1,161,961 | 1.6 ppb |
| Bellevue City Of | 321,349 | - |
| Kent Water Department | 166,421 | 0 (not detected) |
| Redmond Water System City Of | 163,335 | 2 ppb |
| Lakehaven Water And Sewer District | 148,809 | 3.3 ppb |
| Renton City Of | 108,091 | 1.9 ppb |
| Auburn City Of | 107,655 | 2.2 ppb |
| Highline Water District | 100,170 | 1.4 ppb |
| Northshore Utility District | 99,789 | - |
| Sammamish Plateau Water & Sewer | 79,362 | 1.7 ppb |
Next steps for Renton, WA
Test your own tap with a certified lab first-draw sample; Renton, WA may offer free or low-cost kits through the utility. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask King County Water District No 90 whether it covers that cost before hiring anyone - many utilities now do.
These figures describe homes the utility sampled, not your tap. Only your service line record or a test of your own water answers the question for your house. The lead result guide covers how utilities pick the homes they sample. Size matters more than most people expect: small vs large water systems.