El Paso County, CO
These figures come from wells tested in El Paso County, CO, not from any one well.
- Iron is common in wells in El Paso County, CO (11 of 101 tested wells were over that level), so it's worth testing for.
- Manganese is common in wells in El Paso County, CO (17 of 101 tested wells were over that level), so it's worth testing for.
- Sulfate is common in wells in El Paso County, CO (174 of 569 tested wells were over that level), so it's worth testing for.
- Wells in El Paso County, CO are typically very hard (581 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. Colorado'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 | 11% |
| Wells over the level / wells judged | 11 of 101 |
| Median | 0.005 mg/L |
| Years sampled | 1955–2025 |
| Wells | 101 |
| Test results | 940 |
| Wells left out | 1 |
| Sources | USGS (546), CORIVWCH_WQX (1) |
Manganese Recent
| Level it's compared with | 0.05 mg/L |
|---|---|
| Share of wells over the level | 17% |
| Wells over the level / wells judged | 17 of 101 |
| Median | 0.00161 mg/L |
| Years sampled | 1971–2025 |
| Wells | 101 |
| Test results | 953 |
| Wells left out | 1 |
| Sources | USGS (560), CORIVWCH_WQX (1) |
Hardness Recent
| Level it's compared with | none; hardness is shown in bands |
|---|---|
| Share of wells very hard | 54% |
| Median | 200 mg/L as CaCO₃ |
| Years sampled | 1954–2025 |
| Wells | 581 |
| Test results | 1,058 |
| Wells left out | 1 |
| Sources | USGS (580), CORIVWCH_WQX (1) |
Sulfate Recent
| Level it's compared with | 250 mg/L |
|---|---|
| Share of wells over the level | 31% |
| Wells over the level / wells judged | 174 of 569 |
| Median | 100 mg/L |
| Years sampled | 1954–2025 |
| Wells | 569 |
| Test results | 1,018 |
| Wells left out | 1 |
| Sources | USGS (568), CORIVWCH_WQX (1) |