Lost Lake, WA
Lead detected, under the action levels
Latest 90th-percentile lead: 3.7 ppb (monitoring period 2025-2025). 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.
Lost Lake at a glance
Lost Lake serves about 328 people through 250 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Thurston County, Washington. EPA system ID: WA5302897. Ask the utility on your bill for your address in their service line inventory.
Lead results over time
That is up 1.7 ppb from 2 ppb in the period ending 2024. The highest 90th-percentile result EPA holds for Lost Lake is 3.7 ppb across 2 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 3.7 ppb |
| 2024 | 2 ppb |
Where this result ranks
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. Lost Lake's 3.7 ppb sits at the 86th percentile in Washington and the 86th nationally (higher means more lead).
Other water systems in Thurston County
195 other systems share Thurston County; 49 of them have a higher latest lead result than Lost Lake. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Olympia City Of | 126,966 | 3.4 ppb |
| Lacey Water Department | 105,178 | 6 ppb |
| Tumwater City Of | 51,924 | 8 ppb |
| Yelm City Of | 17,355 | 1.9 ppb |
| Tanglewilde Thompson Place 600 | 7,900 | 2.8 ppb |
| Pattison 500 | 4,643 | 3.1 ppb |
| Grand Mound | 3,764 | 0 (not detected) |
| Tenino City Of | 3,336 | 9 ppb |
| Rainier Water Department | 3,103 | 3.4 ppb |
| Meadows 690 | 3,100 | 5.9 ppb |
Next steps for Port Orchard, WA
Test your own tap with a certified lab first-draw sample; Port Orchard, 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 Lost Lake 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. The action level is dropping - the 10 ppb rule from 2027.