Modoc County, CA
These figures come from wells tested in Modoc County, CA, not from any one well.
- Too few wells have been tested in Modoc County, CA (1 to 2 each) to say how common iron, manganese, sulfate or hardness is.
- 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. 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 Too few
| Level it's compared with | 0.3 mg/L |
|---|---|
| Share of wells over the level | 100% |
| Wells over the level / wells judged | 1 of 1 |
| Median | 0.374 mg/L |
| Years sampled | 2005 |
| Wells | 1 |
| Test results | 1 |
| Wells left out | 15 |
| Sources | USGS (1) |
Fewer than 10 wells behind this figure; treat it as a hint, not a prior.
Manganese Too few
| Level it's compared with | 0.05 mg/L |
|---|---|
| Share of wells over the level | 100% |
| Wells over the level / wells judged | 1 of 1 |
| Median | 0.57 mg/L |
| Years sampled | 2005 |
| Wells | 1 |
| Test results | 1 |
| Wells left out | 12 |
| Sources | USGS (1) |
Fewer than 10 wells behind this figure; treat it as a hint, not a prior.
Hardness Too few
| Level it's compared with | none; hardness is shown in bands |
|---|---|
| Share of wells very hard | 50% |
| Median | 213 mg/L as CaCO₃ |
| Years sampled | 1959–2005 |
| Wells | 2 |
| Test results | 12 |
| Wells left out | 17 |
| Sources | USGS (2) |
Fewer than 10 wells behind this figure; treat it as a hint, not a prior.
Sulfate Too few
| Level it's compared with | 250 mg/L |
|---|---|
| Share of wells over the level | 0.0% |
| Wells over the level / wells judged | 0 of 1 |
| Median | 13.5 mg/L |
| Years sampled | 1959–1976 |
| Wells | 1 |
| Test results | 6 |
| Wells left out | 11 |
| Sources | USGS (1) |
Fewer than 10 wells behind this figure; treat it as a hint, not a prior.