Terrace Lakes Water Company, ID
Lead detected, under the action levels
Latest 90th-percentile lead: 4 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 Terrace Lakes Water Company
Terrace Lakes Water Company serves about 475 people through 420 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Boise County, Idaho. EPA system ID: ID4080047; phone on file: 208-440-4756. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Terrace Lakes Water Company's lead record
That is up 4 ppb from 0 ppb in the period ending 2023. The highest 90th-percentile result EPA holds for Terrace Lakes Water Company is 5 ppb across 6 monitoring periods, none of them over 15 ppb.
| Period ending | 90th-percentile lead |
|---|---|
| 2025 | 4 ppb |
| 2023 | 0 (not detected) |
| 2021 | 4 ppb |
| 2020 | 0 (not detected) |
| 2017 | 0 (not detected) |
| 2016 | 5 ppb |
Against other Idaho systems
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. Terrace Lakes Water Company's 4 ppb sits at the 86th percentile in Idaho and the 87th nationally (higher means more lead).
Neighbouring systems
19 other systems share Boise County; 2 of them have a higher latest lead result than Terrace Lakes Water Company. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Horseshoe Bend Water Supply | 750 | 2 ppb |
| Idaho City Water Dept | 531 | 2 ppb |
| Wilderness Ranch Owners Association Inc | 525 | 4 ppb |
| Mountain View Water And Road Assn | 305 | 2 ppb |
| Castle Mountain Creeks Owners Assn | 250 | 1 ppb |
| Duquette Pines Homeowners Association | 163 | 1 ppb |
| Scriver Woods Homeowners Assn | 160 | 0 (not detected) |
| Mores Creek Rim Ranch Water Dist | 140 | 3 ppb |
| Rivers Point Property Owners Assn | 140 | 3 ppb |
| Valley Hi Estates | 140 | 8 ppb |
Your move
Test your own tap with a certified lab first-draw sample; New Plymouth, 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 Terrace Lakes Water Company 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. The lead result guide covers how utilities pick the homes they sample. Systems that went over once often dip back under; here is what that means.