Pennington County, SD
These figures come from wells tested in Pennington County, SD, not from any one well.
- Iron is common in wells in Pennington County, SD (6 of 34 tested wells were over that level), so it's worth testing for.
- Manganese is common in wells in Pennington County, SD (12 of 34 tested wells were over that level), so it's worth testing for.
- Sulfate is common in wells in Pennington County, SD (137 of 394 tested wells were over that level), so it's worth testing for.
- Wells in Pennington County, SD are typically very hard (406 wells tested).
- Only a test of your own well tells you about your water.
What to test for
Start with the four this site covers:
- iron (common in wells here)
- manganese (common in wells here)
- sulfate (common in wells here)
- hardness
Most well owners also test for these. We point to the source and don't interpret the results.
- arsenic: occurs naturally in groundwater in many regions. USGS: arsenic and drinking water
- nitrate: common near farmland and septic systems. EPA: private drinking water wells
- total coliform bacteria: the standard yearly well check. EPA: private drinking water wells
- lead and copper: from household plumbing, especially when pH is below 6.5. EPA: lead in drinking water
- PFAS: several states run private-well sampling programs. EPA: PFAS
- a certified lab: states certify labs and some run their own private-well programs. South Dakota's certified-lab list (from your state drinking-water program)
The numbers
County figures describe the wells sampled there, not any one well. Exact counts, sample years and sources are below.
Iron Recent
| Level it's compared with | 0.3 mg/L |
|---|---|
| Share of wells over the level | 18% |
| Wells over the level / wells judged | 6 of 34 |
| Median | 0.0105 mg/L |
| Years sampled | 1935–2024 |
| Wells | 34 |
| Test results | 548 |
| Wells left out | 0 |
| Sources | USGS (382) |
Manganese Recent
| Level it's compared with | 0.05 mg/L |
|---|---|
| Share of wells over the level | 35% |
| Wells over the level / wells judged | 12 of 34 |
| Median | 0.00828 mg/L |
| Years sampled | 1938–2024 |
| Wells | 34 |
| Test results | 526 |
| Wells left out | 0 |
| Sources | USGS (376) |
Hardness Recent
| Level it's compared with | none; hardness is shown in bands |
|---|---|
| Share of wells very hard | 64% |
| Median | 211 mg/L as CaCO₃ |
| Years sampled | 1935–2024 |
| Wells | 406 |
| Test results | 631 |
| Wells left out | 0 |
| Sources | USGS (406) |
Sulfate Recent
| Level it's compared with | 250 mg/L |
|---|---|
| Share of wells over the level | 35% |
| Wells over the level / wells judged | 137 of 394 |
| Median | 120 mg/L |
| Years sampled | 1935–2024 |
| Wells | 394 |
| Test results | 589 |
| Wells left out | 0 |
| Sources | USGS (394) |