Cochise County, AZ
These figures come from wells tested in Cochise County, AZ, not from any one well.
- Iron, manganese and sulfate are not common in wells in Cochise County, AZ (13 of 176, 10 of 177 and 76 of 882 tested wells were over). Only a test tells you about your own well.
- Wells in Cochise County, AZ are typically hard (1336 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. 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 | 7.4% |
| Wells over the level / wells judged | 13 of 176 |
| Median | < 0.5 mg/L |
| Years sampled | 1920–2021 |
| Wells | 177 |
| Test results | 1,203 |
| Wells left out | 4 |
| Sources | USGS (333), 21ARIZGW (260), AZDEQ_GW (229) |
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 | 5.6% |
| Wells over the level / wells judged | 10 of 177 |
| Median | < 0.05 mg/L |
| Years sampled | 1956–2021 |
| Wells | 177 |
| Test results | 1,208 |
| Wells left out | 4 |
| Sources | USGS (325), 21ARIZGW (254), AZDEQ_GW (229) |
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 | 37% |
| Median | 146 mg/L as CaCO₃ |
| Years sampled | 1920–2024 |
| Wells | 1,336 |
| Test results | 2,170 |
| Wells left out | 2 |
| Sources | USGS (853), 21ARIZGW (253), AZDEQ_GW (230) |
Sulfate Recent
| Level it's compared with | 250 mg/L |
|---|---|
| Share of wells over the level | 8.6% |
| Wells over the level / wells judged | 76 of 882 |
| Median | 31.15 mg/L |
| Years sampled | 1920–2024 |
| Wells | 882 |
| Test results | 1,294 |
| Wells left out | 2 |
| Sources | USGS (652), AZDEQ_GW (230) |