What was found in ZIP 57555
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 | 1300 µg/L 13% of the EPA limit 10000 µg/L Highest in the ZIP: ROSEBUD RURAL WATER SYSTEM · 5,500 people · 2019 | 1/3 | SYR4 |
| Nitrate-Nitrite | 1300 µg/L 13% of the EPA limit 10000 µg/L Highest in the ZIP: ROSEBUD RURAL WATER SYSTEM · 5,500 people · 2019 | 1/3 | SYR4 |
| Copper | 452.5 µg/L 35% of the EPA limit 1300 µg/L Main supplier: SICANGU MNI WICONI RURAL WATER SYSTEM · 5,610 people · 2018 | 3/3 | SYR4 |
| Barium | 130 µg/L 6.5% of the EPA limit 2000 µg/L Highest in the ZIP: ROSEBUD RURAL WATER SYSTEM · 5,500 people · 2019 | 1/3 | SYR4 |
| Lithium | 69.6 µg/L No EPA limit set Main supplier: SICANGU MNI WICONI RURAL WATER SYSTEM · 5,610 people · 2023 | 2/3 | UCMR-5 |
| TTHM | 47.2 µg/L 59% of the EPA limit 80 µg/L Main supplier: SICANGU MNI WICONI RURAL WATER SYSTEM · 5,610 people · 2019
Highest in the ZIP: 51.55 µg/L — MISSION WATER SYSTEM · 1,500 people · 2019 | 3/3 | SYR4 |
| Total Haloacetic Acids (HAA5) | 32.86 µg/L 55% of the EPA limit 60 µg/L Main supplier: SICANGU MNI WICONI RURAL WATER SYSTEM · 5,610 people · 2019
Highest in the ZIP: 35.8 µg/L — MISSION WATER SYSTEM · 1,500 people · 2019 | 3/3 | SYR4 |
| Lead | 3.92 µg/L 26% of the EPA limit 15 µg/L Main supplier: SICANGU MNI WICONI RURAL WATER SYSTEM · 5,610 people · 2018
Highest in the ZIP: 6.94 µg/L — MISSION WATER SYSTEM · 1,500 people · 2018 | 3/3 | SYR4 |
| Arsenic | 4 µg/L 40% of the EPA limit 10 µg/L Highest in the ZIP: ROSEBUD RURAL WATER SYSTEM · 5,500 people · 2019 | 1/3 | SYR4 |
| Gross Alpha, Excl. Radon And U | 2.7 pCi/L 18% of the EPA limit 15 pCi/L Highest in the ZIP: ROSEBUD RURAL WATER SYSTEM · 5,500 people · 2019 | 1/3 | SYR4 |
| Combined Uranium | 2.384 µg/L 7.9% of the EPA limit 30 µg/L Highest in the ZIP: ROSEBUD RURAL WATER SYSTEM · 5,500 people · 2013 | 1/3 | SYR4 |
| Selenium | 1.17 µg/L 2.3% of the EPA limit 50 µg/L Highest in the ZIP: ROSEBUD RURAL WATER SYSTEM · 5,500 people · 2019 | 1/3 | SYR4 |
| Chromium | 0.7300 µg/L 0.7% of the EPA limit 100 µg/L Highest in the ZIP: ROSEBUD RURAL WATER SYSTEM · 5,500 people · 2019 | 1/3 | SYR4 |
| Lead | 0.0011 mg/L 7.3% of the EPA limit 0.0150 mg/L Main supplier: SICANGU MNI WICONI RURAL WATER SYSTEM · 5,610 people · 2025 | 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 57555
| Supplier | State | Population served |
|---|---|---|
| SICANGU MNI WICONI RURAL WATER SYSTEM | SD | 5,610 |
| ROSEBUD RURAL WATER SYSTEM | SD | 5,500 |
| MISSION WATER SYSTEM | SD | 1,500 |
Frequently asked questions about ZIP 57555 tap water
Is the tap water in ZIP 57555 safe to drink?
EPA testing detected 14 contaminants across the water suppliers serving ZIP 57555. 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 57555?
3 public water suppliers report EPA drinking-water monitoring for ZIP 57555. Each is listed above with its population served.
What contaminants are in ZIP 57555's water?
EPA monitoring detected Nitrate, Nitrate-Nitrite, Copper, Barium, Lithium, and others across this ZIP's suppliers. The full list with levels and sources is above.