What was found in ZIP 57745
The level at this ZIP's main supplier, the highest level anywhere in it, the EPA limit for each, and where the figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 2570 µg/L 26% of the EPA limit 10000 µg/L Main supplier: HILL CITY · 872 people · 2019 | 1/3 | SYR4 |
| Copper | 991.5999999999998 µg/L 76% of the EPA limit 1300 µg/L Main supplier: HILL CITY · 872 people · 2017 | 3/3 | SYR4 |
| Fluoride | 200 µg/L 5% of the EPA limit 4000 µg/L Highest in the ZIP: APPLE SPRINGS SUBDIVISION · 180 people · 2019 | 1/3 | SYR4 |
| Barium | 80 µg/L 4% of the EPA limit 2000 µg/L Main supplier: HILL CITY · 872 people · 2014
Highest in the ZIP: 133 µg/L — APPLE SPRINGS SUBDIVISION · 180 people · 2019 | 2/3 | SYR4 |
| TTHM | 33.78 µg/L 42% of the EPA limit 80 µg/L Main supplier: HILL CITY · 872 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 15.634999999999998 µg/L 26% of the EPA limit 60 µg/L Main supplier: HILL CITY · 872 people · 2019 | 1/3 | SYR4 |
| Gross Alpha, Excl. Radon And U | 4.404999999999999 pCi/L 29% of the EPA limit 15 pCi/L Main supplier: HILL CITY · 872 people · 2014
Highest in the ZIP: 13.3 pCi/L — HERMOSA-OLD SYSTEM · 420 people · 2017 | 3/3 | SYR4 |
| Arsenic | 9 µg/L 90% of the EPA limit 10 µg/L Main supplier: HILL CITY · 872 people · 2019 | 1/3 | SYR4 |
| Lead | 2 µg/L 13% of the EPA limit 15 µg/L Main supplier: HILL CITY · 872 people · 2017 | 3/3 | SYR4 |
| Lead | 0.0010 mg/L 6.7% of the EPA limit 0.0150 mg/L Main supplier: HILL CITY · 872 people · 2025
Highest in the ZIP: 0.0070 mg/L — HERMOSA-OLD SYSTEM · 420 people · 2023 | 3/3 | LCR |
Each bar shows the measured level as a share of the EPA limit: green is
well under, amber is close to it, red is over. For lead and copper the
limit applies to exactly the 90th-percentile figure shown, so red there
means a real exceedance. For everything else the limit applies to a
running annual average while the figure is the 95th percentile of the
system's samples — over 100% is worth reading, but is not by itself a
violation.
Formal violations are listed separately.
Water suppliers serving ZIP 57745
| Supplier | State | Population served |
|---|---|---|
| HILL CITY | SD | 872 |
| HERMOSA-OLD SYSTEM | SD | 420 |
| APPLE SPRINGS SUBDIVISION | SD | 180 |
Frequently asked questions about ZIP 57745 tap water
Is the tap water in ZIP 57745 safe to drink?
EPA testing detected 10 contaminants across the water suppliers serving ZIP 57745. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and your utility's annual Consumer Confidence Report for the official status.
Which water suppliers serve ZIP 57745?
3 public water suppliers report EPA drinking-water monitoring for ZIP 57745. Each is listed above with its population served.
What contaminants are in ZIP 57745's water?
EPA monitoring detected Nitrate, Copper, Fluoride, Barium, TTHM, and others across this ZIP's suppliers. The full list with levels and sources is above.