Santa Barbara County, CA
These figures come from wells tested in Santa Barbara County, CA, not from any one well.
- Iron is common in wells in Santa Barbara County, CA (11 of 93 tested wells were over that level), so it's worth testing for.
- Manganese is common in wells in Santa Barbara County, CA (16 of 88 tested wells were over that level), so it's worth testing for.
- Sulfate is common in wells in Santa Barbara County, CA (205 of 406 tested wells were over that level), so it's worth testing for.
- Wells in Santa Barbara County, CA are typically very hard (520 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. California'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 | 12% |
| Wells over the level / wells judged | 11 of 93 |
| Median | 0.0144 mg/L |
| Years sampled | 1924–2025 |
| Wells | 98 |
| Test results | 674 |
| Wells left out | 692 |
| Sources | USGS (267) |
Manganese Recent
| Level it's compared with | 0.05 mg/L |
|---|---|
| Share of wells over the level | 18% |
| Wells over the level / wells judged | 16 of 88 |
| Median | 0.0038175 mg/L |
| Years sampled | 1954–2025 |
| Wells | 98 |
| Test results | 399 |
| Wells left out | 419 |
| Sources | USGS (149) |
Hardness Recent
| Level it's compared with | none; hardness is shown in bands |
|---|---|
| Share of wells very hard | 92% |
| Median | 512.5 mg/L as CaCO₃ |
| Years sampled | 1924–2025 |
| Wells | 520 |
| Test results | 1,658 |
| Wells left out | 1,132 |
| Sources | USGS (520) |
Sulfate Recent
| Level it's compared with | 250 mg/L |
|---|---|
| Share of wells over the level | 50% |
| Wells over the level / wells judged | 205 of 406 |
| Median | 259 mg/L |
| Years sampled | 1924–2025 |
| Wells | 406 |
| Test results | 1,345 |
| Wells left out | 1,023 |
| Sources | USGS (406) |