Tyonek Water System, AK
Lead detected, under the action levels
Latest 90th-percentile lead: 4.9 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.
Tyonek Water System at a glance
Tyonek Water System serves about 206 people through 97 service connections, which makes it a very small system under EPA's size classes. It is owned by a Native American tribe and draws groundwater, in Kenai Peninsula Borough County, Alaska. EPA system ID: AK2240472; phone on file: 907-583-2201. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
Against the period ending 2018 (4.5 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Tyonek Water System is 9.1 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 4.9 ppb |
| 2018 | 4.5 ppb |
| 2018 | 6.8 ppb |
| 2016 | 9.1 ppb |
How Tyonek Water System compares
Of the 394 Alaska systems with a lead result, the median latest reading is 1.6 ppb; 3 are over 15 ppb right now and 53 have gone over at some point. Tyonek Water System's 4.9 ppb sits at the 85th percentile in Alaska and the 90th nationally (higher means more lead).
Other water systems in Kenai Peninsula Borough County
26 other systems share Kenai Peninsula Borough County; 2 of them have a higher latest lead result than Tyonek Water System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Homer Water System | 7,008 | 2 ppb |
| Kenai Water System | 5,700 | 0 (not detected) |
| Soldotna | 4,807 | 4.53 ppb |
| Seward | 3,324 | 0 (not detected) |
| Anchor Point Safe Water Corporation | 1,000 | 6.2 ppb |
| Seward Marine Industrial Cent | 545 | 2.64 ppb |
| Nikishka Bay | 470 | 2.7 ppb |
| Seldovia Water System | 418 | 1.4 ppb |
| Nikolaevsk Community Water System | 360 | 0 (not detected) |
| Voznesenka Village | 300 | 1.1 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Tyonek, AK 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 Tyonek Water System 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.