Mountain Home Air Force Base, ID
Lead detected, under the action levels
Latest 90th-percentile lead: 4 ppb (monitoring period 2026-2028). 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
Mountain Home Air Force Base serves about 7,500 people through 1,053 service connections, which makes it a medium-sized system under EPA's size classes. It is federally owned and draws groundwater, in Elmore County, Idaho. EPA system ID: ID4200054; phone on file: 208-828-1784. 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 4 ppb from 0 ppb in the period ending 2025. The highest 90th-percentile result EPA holds for Mountain Home Air Force Base is 4 ppb across 10 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2028 | 4 ppb |
| 2025 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2022 | 0 (not detected) |
| 2021 | 0 (not detected) |
| 2020 | 0 (not detected) |
| 2020 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2017 | 0 (not detected) |
Where this result ranks
Of the 763 Idaho systems with a lead result, the median latest reading is 1 ppb; 3 are over 15 ppb right now and 46 have gone over at some point. Mountain Home Air Force Base's 4 ppb sits at the 87th percentile in Idaho and the 88th nationally (higher means more lead).
Other water systems in Elmore County
22 other systems share Elmore County; 4 of them have a higher latest lead result than Mountain Home Air Force Base. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Mountain Home, City Of | 14,651 | 0 (not detected) |
| Glenns Ferry City Of | 1,282 | 0 (not detected) |
| Trinity Estates Water Users Assn | 250 | 7 ppb |
| Mellen Subd Water Dist | 250 | 5 ppb |
| Canyon Creek Mobile Home Park | 243 | 3 ppb |
| Summerwind Water Users | 192 | 0 (not detected) |
| Sawtooth Estates Water Users | 175 | 9 ppb |
| Blue Sage Subdivision | 112 | 0 (not detected) |
| Simplot Livestock Company Grandview | 100 | 2 ppb |
| Hamilton Place | 97 | 0 (not detected) |
Your move
Test your own tap with a certified lab first-draw sample; Mountain Home Afb, ID 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 Mountain Home Air Force Base 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.