Hilltop Colony, MT
Lead detected, under the action levels
Latest 90th-percentile lead: 1 ppb (monitoring period 2024-2026). 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.
Who runs the water here
Hilltop Colony serves about 100 people through 12 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Cascade County, Montana. EPA system ID: MT0004854; phone on file: 406-564-1889. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
That is down 9 ppb from 10 ppb in the period ending 2023. The highest 90th-percentile result EPA holds for Hilltop Colony is 10 ppb across 7 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 1 ppb |
| 2023 | 10 ppb |
| 2021 | 1 ppb |
| 2018 | 2 ppb |
| 2018 | 3 ppb |
| 2017 | 7 ppb |
| 2017 | 6 ppb |
How Hilltop Colony compares
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. Hilltop Colony's 1 ppb sits at the 50th percentile in Montana and the 51st nationally (higher means more lead).
Nearby utilities
41 other systems share Cascade County; 8 of them have a higher latest lead result than Hilltop Colony. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Great Falls City Of | 60,000 | 12 ppb |
| Malmstrom Air Force Base | 8,850 | 0 (not detected) |
| Sun Prairie Village County | 1,800 | 1 ppb |
| Black Eagle Cascade County Water Sewer | 1,233 | 0 (not detected) |
| Prairie Water Company | 1,000 | 0 (not detected) |
| Cascade Town Of | 650 | 2 ppb |
| Belt Town Of | 600 | 0 (not detected) |
| Vaughn Cascade County Water And Sewer | 585 | 0 (not detected) |
| Two Buttes Water Users Assn | 525 | 2 ppb |
| Gore Hill County Water Dist | 500 | 1 ppb |
Your move
Test your own tap with a certified lab first-draw sample; Stockett, 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 Hilltop Colony 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.