Seminole County, FL
These figures come from wells tested in Seminole County, FL, not from any one well.
- Iron is common in wells in Seminole County, FL (25 of 66 tested wells were over that level), so it's worth testing for.
- Sulfate is common in wells in Seminole County, FL (10 of 67 tested wells were over that level), so it's worth testing for.
- Manganese is not common in wells in Seminole County, FL (0 of 62 tested wells were over). Only a test tells you about your own well.
- Wells in Seminole County, FL are typically hard (71 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)
- sulfate (common in wells here)
- 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. Florida'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 | 38% |
| Wells over the level / wells judged | 25 of 66 |
| Median | 0.113603 mg/L |
| Years sampled | 1973–2025 |
| Wells | 66 |
| Test results | 301 |
| Wells left out | 0 |
| Sources | 21FLSJWM_WQX (45), 21FLGW_WQX (17), 21FLSJWM (4), USGS (4) |
Manganese Recent
| Level it's compared with | 0.05 mg/L |
|---|---|
| Share of wells over the level | 0.0% |
| Wells over the level / wells judged | 0 of 62 |
| Median | 0.00615674 mg/L |
| Years sampled | 2013–2025 |
| Wells | 62 |
| Test results | 276 |
| Wells left out | 0 |
| Sources | 21FLSJWM_WQX (45), 21FLGW_WQX (17) |
Hardness Recent
| Level it's compared with | none; hardness is shown in bands |
|---|---|
| Share of wells very hard | 37% |
| Median | 156 mg/L as CaCO₃ |
| Years sampled | 1973–2025 |
| Wells | 71 |
| Test results | 367 |
| Wells left out | 0 |
| Sources | 21FLSJWM_WQX (45), 21FLGW_WQX (17), USGS (5), 21FLSJWM (4) |
Sulfate Recent
| Level it's compared with | 250 mg/L |
|---|---|
| Share of wells over the level | 15% |
| Wells over the level / wells judged | 10 of 67 |
| Median | 12.456 mg/L |
| Years sampled | 1973–2025 |
| Wells | 67 |
| Test results | 367 |
| Wells left out | 0 |
| Sources | 21FLSJWM_WQX (45), 21FLGW_WQX (17), USGS (5) |