Koliganek Water System, AK
Lead detected, under the action levels
Latest 90th-percentile lead: 2.7 ppb (monitoring period 2026-2026). 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.
About Koliganek Water System
Koliganek Water System serves about 170 people through 40 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 Dillingham Census Area County, Alaska. EPA system ID: AK2260040; phone on file: 907-596-3434. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
That is down 3.1 ppb from 5.8 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Koliganek Water System is 8.8 ppb across 8 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 2.7 ppb |
| 2025 | 5.8 ppb |
| 2024 | 3.6 ppb |
| 2024 | 4.5 ppb |
| 2023 | 5.1 ppb |
| 2022 | 6.5 ppb |
| 2022 | 6.5 ppb |
| 2021 | 8.8 ppb |
Against other Alaska systems
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. Koliganek Water System's 2.7 ppb sits at the 70th percentile in Alaska and the 79th nationally (higher means more lead).
Neighbouring systems
10 other systems share Dillingham Census Area County; 4 of them have a higher latest lead result than Koliganek Water System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Dillingham Water System | 2,419 | 0.4 ppb |
| Togiak Water System | 910 | 0.43 ppb |
| New Stuyahok Water System | 566 | 0.37 ppb |
| Bbahc - Kanakanak Hospital | 305 | 11 ppb |
| Manokotak Water System | 293 | 6.07 ppb |
| Manokotak Heights W/S | 215 | 0 (not detected) |
| Clarks Point Water System | 128 | 10.1 ppb |
| Twin Hills Water System | 87 | 0.69 ppb |
| Salmon Roe | 31 | 5.4 ppb |
| Nina Nicholson Subdivision | 31 | 0 (not detected) |
Next steps for Koliganek, AK
Test your own tap with a certified lab first-draw sample; Koliganek, 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 Koliganek Water System whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 2100 ppb (copper action level 1,300 ppb).
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. Why sampled homes are the worst-case ones is in the guide to reading the number. The action level is dropping - the 10 ppb rule from 2027.