Mobile City 3, 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.
Mobile City 3 at a glance
Mobile City 3 serves about 40 people through 40 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws surface water, in Lewis And Clark County, Montana. EPA system ID: MT0005088; phone on file: 406-697-5900. They can tell you what your service line is made of and whether they pay to replace it.
Every lead result on file
That is up 2 ppb from 0 ppb in the period ending 2022. The highest 90th-percentile result EPA holds for Mobile City 3 is 2 ppb across 3 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 2 ppb |
| 2022 | 0 (not detected) |
| 2021 | 0 (not detected) |
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. Mobile City 3's 2 ppb sits at the 64th percentile in Montana and the 69th nationally (higher means more lead).
Other water systems in Lewis And Clark County
50 other systems share Lewis And Clark County; 11 of them have a higher latest lead result than Mobile City 3. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Helena Water System | 32,091 | 3 ppb |
| East Helena City Of | 2,114 | 1 ppb |
| Eastgate Village Sewer And Water | 2,000 | 1 ppb |
| Va Medical Center Helena | 1,275 | 7 ppb |
| Helena Leisure Llc | 1,200 | 1 ppb |
| Ten Mile And Pleasant Valley Wua | 750 | 0 (not detected) |
| North Star Pud | 715 | 7 ppb |
| Treasure State Acres Wua | 483 | 2 ppb |
| La Casa Grande Water And Sewer District | 404 | 2 ppb |
| Skyview Water And Sewer Utility | 400 | 2 ppb |
What to do in your house
Test your own tap with a certified lab first-draw sample; Billings, 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 Mobile City 3 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. Size matters more than most people expect: small vs large water systems.