What was found in Pine Ridge's water
The level at the city's main supplier, the highest level anywhere in the city, the EPA limit for each, and where every figure comes from.
| Contaminant | Level vs EPA limit | Suppliers | Source |
|---|---|---|---|
| Nitrate | 1700 µg/L 17% of the EPA limit 10000 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2019
Highest in the city: 2850 µg/L — OGLALA RWS PIPELINE · 3,562 people · 2019 | 7/18 | SYR4 |
| Nitrate-Nitrite | 1621.6 µg/L 16% of the EPA limit 10000 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2019
Highest in the city: 2380 µg/L — OGLALA RWS PIPELINE · 3,562 people · 2013 | 6/18 | SYR4 |
| Fluoride | 1300 µg/L 33% of the EPA limit 4000 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2018 | 7/18 | SYR4 |
| Copper | 220.6 µg/L 17% of the EPA limit 1300 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2019
Highest in the city: 488.65 µg/L — ALLEN WATER SYSTEM · 420 people · 2019 | 16/18 | SYR4 |
| Barium | 73.5 µg/L 3.7% of the EPA limit 2000 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2018
Highest in the city: 134.5 µg/L — NORTH MARTIN WATER SYSTEM · 78 people · 2019 | 7/18 | SYR4 |
| Lithium | 54.9 µg/L No EPA limit set Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2023
Highest in the city: 71 µg/L — KYLE WATER SYSTEM · 6,526 people · 2025 | 3/18 | UCMR-5 |
| TTHM | 4.357 µg/L 5.4% of the EPA limit 80 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2019
Highest in the city: 62.15 µg/L — EAGLE NEST HOMES · 195 people · 2019 | 16/18 | SYR4 |
| Lead | 10.8 µg/L 72% of the EPA limit 15 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2019
Highest in the city: 53 µg/L — WAKPAMNI WATER SYSTEM · 104 people · 2019 | 9/18 | SYR4 |
| Total Haloacetic Acids (HAA5) | 15 µg/L 25% of the EPA limit 60 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2019
Highest in the city: 42.5 µg/L — WANBLEE WATER SYSTEM · 773 people · 2019 | 16/18 | SYR4 |
| Combined Uranium | 32.92 µg/L 110% of the EPA limit, at the 95th percentile of samples — 30 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2019 | 5/18 | SYR4 |
| Selenium | 21 µg/L 42% of the EPA limit 50 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2018 | 4/18 | SYR4 |
| Gross Alpha, Excl. Radon And U | 15.05 pCi/L 100% of the EPA limit, at the 95th percentile of samples — 15 pCi/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2019 | 6/18 | SYR4 |
| Arsenic | 6 µg/L 60% of the EPA limit 10 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2018
Highest in the city: 11.8 µg/L — NORTH MARTIN WATER SYSTEM · 78 people · 2019 | 5/18 | SYR4 |
| Chromium | 6 µg/L 6% of the EPA limit 100 µg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2018 | 5/18 | SYR4 |
| Combined Radium (-226 And -228) | 2.17 pCi/L 43% of the EPA limit 5 pCi/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2019 | 7/18 | SYR4 |
| Methoxychlor | 0.3100 µg/L 0.8% of the EPA limit 40 µg/L Highest in the city: OGLALA RWS PIPELINE · 3,562 people · 2019 | 1/18 | SYR4 |
| Hexachlorocyclopentadiene | 0.2200 µg/L 0.4% of the EPA limit 50 µg/L Highest in the city: KYLE WATER SYSTEM · 6,526 people · 2019 | 1/18 | SYR4 |
| Lead | 0.0 mg/L 0% of the EPA limit 0.0150 mg/L Main supplier: PINE RIDGE WATER SYSTEM · 7,482 people · 2023
Highest in the city: 0.0028 mg/L — WANBLEE EAST · 2,179 people · 2025 | 18/18 | 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.
These are the utilities' own EPA-reported results, not a city-wide
average. A detection means the lab measured the
substance — it isn't the same as exceeding a legal limit. Hover a source
tag to see the EPA program and years behind each figure.
Water suppliers serving Pine Ridge
| Supplier | Population served |
|---|---|
| PINE RIDGE WATER SYSTEM | 7,482 |
| KYLE WATER SYSTEM | 6,526 |
| OGLALA RWS PIPELINE | 3,562 |
| WANBLEE EAST | 2,179 |
| WHITE HORSE CREEK WATER SYSTEM | 1,690 |
| WANBLEE WATER SYSTEM | 773 |
| RED CLOUD SCHOOL | 501 |
| ALLEN WATER SYSTEM | 420 |
| SUNRISE WATER SYSTEM | 380 |
| PINE RIDGE HOSPITAL | 316 |
| WOUNDED KNEE WATER SYSTEM | 255 |
| EAGLE NEST HOMES | 195 |
| RED ROCKS WATER SYSTEM | 125 |
| WAKPAMNI WATER SYSTEM | 104 |
| POTATO CREEK WATER SYSTEM | 95 |
| NORTH MARTIN WATER SYSTEM | 78 |
| WOLF CREEK WATER SYSTEM | 65 |
| NORTH ALLEN WATER SYSTEM | 65 |
Frequently asked questions about Pine Ridge tap water
Is Pine Ridge tap water safe to drink?
EPA testing detected 18 contaminants in the water serving Pine Ridge. A detection isn't the same as a violation — most detected levels are within federal limits. Check the level and source for each contaminant above, and your utility's annual Consumer Confidence Report for the official compliance status.
How many water suppliers serve Pine Ridge?
18 public water suppliers report drinking-water monitoring for Pine Ridge, South Dakota to the EPA. Each is listed above with its population served.
What contaminants are in Pine Ridge's water?
The contaminants EPA monitoring detected in Pine Ridge include Nitrate, Nitrate-Nitrite, Fluoride, Copper, Barium. The full list, with the level at the main supplier and the data source, is in the table above.
Where does this data come from?
Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.