La Paz County, AZ
These figures come from wells tested in La Paz County, AZ, not from any one well.
- Sulfate is common in wells in La Paz County, AZ (148 of 482 tested wells were over that level), so it's worth testing for.
- Iron and manganese are not common in wells in La Paz County, AZ (1 of 185 and 8 of 187 tested wells were over). Only a test tells you about your own well.
- Wells in La Paz County, AZ are typically hard (537 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:
- sulfate (common in wells here)
- iron
- manganese
- 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. Arizona'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 | 0.5% |
| Wells over the level / wells judged | 1 of 185 |
| Median | < 0.5 mg/L |
| Years sampled | 1957–2014 |
| Wells | 186 |
| Test results | 659 |
| Wells left out | 5 |
| Sources | USGS (198), AZDEQ_GW (176), 21ARIZGW (59) |
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 | 4.3% |
| Wells over the level / wells judged | 8 of 187 |
| Median | < 0.1 mg/L |
| Years sampled | 1973–2014 |
| Wells | 187 |
| Test results | 652 |
| Wells left out | 14 |
| Sources | USGS (191), AZDEQ_GW (177), 21ARIZGW (60) |
More than half the wells had results below the lab's detection limit, so the median is reported as below that limit.
Hardness Recent
| Level it's compared with | none; hardness is shown in bands |
|---|---|
| Share of wells very hard | 46% |
| Median | 165 mg/L as CaCO₃ |
| Years sampled | 1942–2014 |
| Wells | 537 |
| Test results | 1,126 |
| Wells left out | 1 |
| Sources | USGS (304), AZDEQ_GW (177), 21ARIZGW (56) |
Sulfate Recent
| Level it's compared with | 250 mg/L |
|---|---|
| Share of wells over the level | 31% |
| Wells over the level / wells judged | 148 of 482 |
| Median | 129.25 mg/L |
| Years sampled | 1942–2014 |
| Wells | 482 |
| Test results | 784 |
| Wells left out | 69 |
| Sources | USGS (305), AZDEQ_GW (177) |