Midvale Water System, ID
Lead detected, under the action levels
Latest 90th-percentile lead: 1 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.
About Midvale Water System
Midvale Water System serves about 144 people through 113 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Washington County, Idaho. EPA system ID: ID3440007; phone on file: 208-888-3000. Ask them for your address in their service line inventory - every system had to publish one by Oct 2024.
Midvale Water System's lead record
Against the period ending 2022 (0 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Midvale Water System is 1 ppb across 4 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 1 ppb |
| 2022 | 0 (not detected) |
| 2019 | 0 (not detected) |
| 2016 | 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. Midvale Water System's 1 ppb sits at the 46th percentile in Idaho and the 52nd nationally (higher means more lead).
Nearby utilities
2 other systems share Washington County; 0 of them have a higher latest lead result than Midvale Water System. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Weiser City Of | 5,630 | 0 (not detected) |
| Cambridge City Of | 335 | 1 ppb |
Next steps for Notus, ID
Test your own tap with a certified lab first-draw sample; Notus, 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 Midvale Water System 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.