Roundup Water Department, MT
Exceeded the action level in the past
Latest 90th-percentile lead: 3 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. The latest result is under the action level, but this system has gone over 15 ppb before. Lead comes from pipes, not the source water, so a home with a lead service line can still be exposed. Test your own tap.
Roundup Water Department at a glance
Roundup Water Department serves about 1,900 people through 878 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 Musselshell County, Montana. EPA system ID: MT0000321; phone on file: 406-323-2804. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Lead results over time
That is down 5 ppb from 8 ppb in the period ending 2026. The highest 90th-percentile result EPA holds for Roundup Water Department is 41 ppb across 6 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2026 | 3 ppb |
| 2026 | 8 ppb |
| 2025 | 41 ppb over 15 |
| 2024 | 5 ppb |
| 2021 | 10 ppb |
| 2018 | 1 ppb |
How Roundup Water Department 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. Roundup Water Department's 3 ppb sits at the 86th percentile in Montana and the 82nd nationally (higher means more lead).
Nearby utilities
3 other systems share Musselshell County; 0 of them have a higher latest lead result than Roundup Water Department. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Melstone Town Of | 170 | 3 ppb |
| Musselshell Community County Wsd | 75 | 3 ppb |
| Sunset Colony Unapproved | 75 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; Roundup, 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 Roundup Water Department 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. More in what a past exceedance means today.