Yakima County, WA
These figures come from wells tested in Yakima County, WA, not from any one well.
- Iron, manganese and sulfate are not common in wells in Yakima County, WA (2 of 67, 6 of 67 and 3 of 350 tested wells were over). Only a test tells you about your own well.
- Wells in Yakima County, WA are typically hard (348 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
- manganese
- hardness
- sulfate
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. Washington'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 | 3.0% |
| Wells over the level / wells judged | 2 of 67 |
| Median | < DL mg/L |
| Years sampled | 1939–2024 |
| Wells | 67 |
| Test results | 483 |
| Wells left out | 12 |
| Sources | USGS (311) |
More than half the wells had results below the lab's detection limit, so the median is reported as below that limit.
Manganese Recent
| Level it's compared with | 0.05 mg/L |
|---|---|
| Share of wells over the level | 9.0% |
| Wells over the level / wells judged | 6 of 67 |
| Median | 0.00128 mg/L |
| Years sampled | 1951–2024 |
| Wells | 67 |
| Test results | 441 |
| Wells left out | 4 |
| Sources | USGS (289) |
Hardness Recent
| Level it's compared with | none; hardness is shown in bands |
|---|---|
| Share of wells very hard | 33% |
| Median | 136.5 mg/L as CaCO₃ |
| Years sampled | 1939–2024 |
| Wells | 348 |
| Test results | 1,217 |
| Wells left out | 11 |
| Sources | USGS (321), YAKIMAVLYDAIRIES_WQX (27) |
Sulfate Recent
| Level it's compared with | 250 mg/L |
|---|---|
| Share of wells over the level | 0.9% |
| Wells over the level / wells judged | 3 of 350 |
| Median | 14 mg/L |
| Years sampled | 1939–2024 |
| Wells | 350 |
| Test results | 1,216 |
| Wells left out | 11 |
| Sources | USGS (323), YAKIMAVLYDAIRIES_WQX (27) |