Cook, MN
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. The latest 90th-percentile result was reported as 0 (not detected at the lab's limit). That says the sampled homes were low, not that your home has no lead service line. Check your utility's service line inventory for your address.
Who runs the water here
Cook serves about 574 people through 208 service connections, which makes it a small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in St. Louis County, Minnesota. EPA system ID: MN1690009; phone on file: 2186662200. They can tell you what your service line is made of and whether they pay to replace it.
Lead results over time
Against the period ending 2025 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Cook is 0 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 0 (not detected) |
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
Against other Minnesota systems
Of the 966 Minnesota systems with a lead result, the median latest reading is 0 ppb; 7 are over 15 ppb right now and 48 have gone over at some point. Cook's reported as 0 (not detected) sits at the 31st percentile in Minnesota and the 23rd nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Nearby utilities
29 other systems share St. Louis County; 10 of them have a higher latest lead result than Cook. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Duluth | 86,859 | 8 ppb |
| Hibbing | 16,028 | 14 ppb |
| Virginia | 8,361 | 0 (not detected) |
| Hermantown | 7,215 | 0 (not detected) |
| Chisholm | 4,940 | 4 ppb |
| Eveleth | 3,770 | 3 ppb |
| Ely | 3,258 | 7 ppb |
| Proctor | 3,099 | 2 ppb |
| Mountain Iron | 2,880 | 0 (not detected) |
| Hoyt Lakes | 2,020 | 0 (not detected) |
Next steps for Cook, MN
Look up your address in Cook's service line inventory. If it says lead, galvanized or unknown, test your tap. If your own line is lead, replacing the private side runs about $1,200-$12,300 (EPA average about $4,700). Ask Cook whether it covers that cost before hiring anyone - many utilities now do. Its latest copper 90th percentile is 1870 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. The lead result guide covers how utilities pick the homes they sample. Small systems behave differently: why small systems go over more often.