Sunset Colony Unapproved, MT
Lead reported as not detected
Latest 90th-percentile lead: reported as 0 (not detected) (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. 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.
Sunset Colony Unapproved at a glance
Sunset Colony Unapproved serves about 75 people through 2 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Musselshell County, Montana. EPA system ID: MT0005111; phone on file: 406-855-0078. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Sunset Colony Unapproved's lead record
Against the period ending 2025 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Sunset Colony Unapproved is 0 ppb across 2 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 0 (not detected) |
| 2025 | 0 (not detected) |
Where this result ranks
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. Sunset Colony Unapproved's reported as 0 (not detected) sits at the 14th percentile in Montana and the 7th nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Other water systems in Musselshell County
3 other systems share Musselshell County; 3 of them have a higher latest lead result than Sunset Colony Unapproved. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Roundup Water Department | 1,900 | 3 ppb |
| Melstone Town Of | 170 | 3 ppb |
| Musselshell Community County Wsd | 75 | 3 ppb |
Next steps for Roundup, MT
Look up your address in Sunset Colony Unapproved'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 Sunset Colony Unapproved 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. Small systems behave differently: why small systems go over more often.