Green Brier Subdivision, IA
Exceeded the action level in the past
Latest 90th-percentile lead: reported as 0 (not detected) (monitoring period 2023-2023). 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.
Who runs the water here
Green Brier Subdivision serves about 35 people through 17 service connections, which makes it a very small system under EPA's size classes. It is privately owned and draws groundwater, in Dubuque County, Iowa. EPA system ID: IA3126307; phone on file: 563-590-7483. Call that number and ask whether your address has a lead, galvanized or unknown service line.
Every lead result on file
Against the period ending 2022 (0.9 ppb) the latest result is about the same. The highest 90th-percentile result EPA holds for Green Brier Subdivision is 16.8 ppb across 6 monitoring periods, 1 of them over the 15 ppb action level.
| Period ending | 90th-percentile lead |
|---|---|
| 2023 | 0 (not detected) |
| 2022 | 0.9 ppb |
| 2021 | 1.2 ppb |
| 2021 | 2.3 ppb |
| 2020 | 16.8 ppb over 15 |
| 2017 | 4 ppb |
Against other Iowa systems
Of the 1,066 Iowa systems with a lead result, the median latest reading is 1.4 ppb; 4 are over 15 ppb right now and 36 have gone over at some point. Green Brier Subdivision's reported as 0 (not detected) sits at the 0th percentile in Iowa and the 1st nationally (higher means more lead). Systems reporting 0 tie at the bottom, so the rank mostly reflects size among them.
Neighbouring systems
29 other systems share Dubuque County; 18 of them have a higher latest lead result than Green Brier Subdivision. If you are unsure which one supplies your house, the name on your water bill decides it.
| System | People | Latest lead |
|---|---|---|
| Dubuque Water Works | 59,667 | 5 ppb |
| Asbury Municipal Water System | 5,943 | 0 (not detected) |
| Dyersville Municipal Water Co | 4,477 | 1.7 ppb |
| Cascade Municipal Water Supply | 2,386 | 0 (not detected) |
| Peosta Water Supply | 2,278 | 0.5 ppb |
| Epworth Water Supply | 2,023 | 5.75 ppb |
| Farley Water Supply | 1,766 | 1.3 ppb |
| Alpine Park | 932 | 4.6 ppb |
| Table Mound Park | 455 | 0 (not detected) |
| New Vienna Water Supply | 382 | 0 (not detected) |
What to do in your house
Test your own tap with a certified lab first-draw sample; Dubuque, IA 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 Green Brier Subdivision 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. Why sampled homes are the worst-case ones is in the guide to reading the number. Why an old exceedance still matters: over the limit before, under it now.