Jefferson County, FL
These figures come from wells tested in Jefferson County, FL, not from any one well.
- Iron is common in wells in Jefferson County, FL (13 of 35 tested wells were over that level), so it's worth testing for.
- Manganese and sulfate are not common in wells in Jefferson County, FL (2 of 25 and 0 of 32 tested wells were over). Only a test tells you about your own well.
- Wells in Jefferson County, FL are typically hard (44 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
- 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. 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 | 37% |
| Wells over the level / wells judged | 13 of 35 |
| Median | 0.186508 mg/L |
| Years sampled | 1982–2025 |
| Wells | 35 |
| Test results | 162 |
| Wells left out | 0 |
| Sources | 21FLGW_WQX (19), 21FLSUW (12), 21FLSUW_WQX (4), USGS (1) |
Manganese Recent
| Level it's compared with | 0.05 mg/L |
|---|---|
| Share of wells over the level | 8.0% |
| Wells over the level / wells judged | 2 of 25 |
| Median | 0.00453249 mg/L |
| Years sampled | 1982–2025 |
| Wells | 25 |
| Test results | 63 |
| Wells left out | 0 |
| Sources | 21FLGW_WQX (19), 21FLSUW_WQX (4), 21FLSUW (2), USGS (1) |
Hardness Recent
| Level it's compared with | none; hardness is shown in bands |
|---|---|
| Share of wells very hard | 30% |
| Median | 161.577 mg/L as CaCO₃ |
| Years sampled | 1982–2025 |
| Wells | 44 |
| Test results | 203 |
| Wells left out | 0 |
| Sources | 21FLGW_WQX (19), 21FLSUW (12), 21FLGWMS_WQX (7), 21FLSUW_WQX (4), USGS (2) |
Sulfate Recent
| Level it's compared with | 250 mg/L |
|---|---|
| Share of wells over the level | 0.0% |
| Wells over the level / wells judged | 0 of 32 |
| Median | 3.35 mg/L |
| Years sampled | 1982–2025 |
| Wells | 32 |
| Test results | 110 |
| Wells left out | 0 |
| Sources | 21FLGW_WQX (19), 21FLGWMS_WQX (7), 21FLSUW_WQX (4), USGS (2) |