Cooke City Water District, MT
Lead detected, under the action levels
Latest 90th-percentile lead: 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.
About Cooke City Water District
Cooke City Water District serves about 300 people through 98 service connections, which makes it a very small system under EPA's size classes. It is owned by a local government (city, town, county or district) and draws groundwater, in Park County, Montana. EPA system ID: MT0000187. Ask the utility on your bill for your address in their service line inventory.
Every lead result on file
Against the period ending 2019 (3 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Cooke City Water District is 3 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 2 ppb |
| 2019 | 3 ppb |
| 2016 | 2.4 ppb |
Against other Montana systems
Of the 753 Montana systems with a lead result, the median latest reading is 1 ppb; 5 are over 15 ppb right now and 28 have gone over at some point. Cooke City Water District's 2 ppb sits at the 71st percentile in Montana and the 71st nationally (higher means more lead).
Neighbouring systems
14 other systems share Park County; 2 of them have a higher latest lead result than Cooke City Water District. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Livingston City Of | 9,200 | 2 ppb |
| Gardiner Park Co Water Dist | 700 | 2 ppb |
| Clyde Park Water Dept | 300 | 2.49 ppb |
| Wilsall Water District | 250 | 2 ppb |
| East Gate Work Camp | 208 | 0 (not detected) |
| Golden Age Village | 180 | 1 ppb |
| Cinnabar The | 175 | 15 ppb |
| Avalon Subdivision | 135 | 0.44 ppb |
| Windmill Trailer Park Well 2 | 125 | 0 (not detected) |
| Windmill Trailer Park Well 1 | 110 | 2 ppb |
Next steps for Bozeman, MT
Test your own tap with a certified lab first-draw sample; Bozeman, MT 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 Cooke City Water District 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. What a 90th-percentile result does and does not tell you: how to read a lead result. The action level is dropping - the 10 ppb rule from 2027.