Typical values from 86 sampled wells in Madison County · Full groundwater profile
What Are You Noticing in Your Water?
Pre-selected from Madison County well data. Untick anything you do not notice in your own water.
Based on the contaminants most commonly reported in this region. Always confirm with a certified lab water test before buying equipment.
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Explore Madison County and nearby counties
Private wells are the main water source in Madison County, in North Florida: 66.9% of built parcels, roughly 4,846 properties, draw drinking water from an onsite well, according to the Florida Department of Health's 2022 inventory.
Most groundwater pumped in Madison County comes from the Floridan Aquifer (USGS, 2015 withdrawals). Samples from 86 local wells put the median hardness at 8.6 gpg (hard) and median iron at 0.07 mg/L. The county's largest communities are Madison, Greenville and Lee.
In this guide
Groundwater Profile: Madison County
Most groundwater pumped in Madison County comes from the Floridan Aquifer (USGS, 2015 withdrawals). Across 86 sampled wells, the median hardness is 8.6 gpg, which the USGS classes as hard. It applies to wells across Madison County, including around Madison, Greenville and Lee.
What shows up in local well samples:
- HardnessMedian 8.6 gpg; 78% of 86 sampled wells above 7 gpg
Calcium and magnesium dissolved from limestone. Leaves scale on fixtures and water heaters and reduces soap lather. Not a health risk.
Water softener sizing
Hydrogen sulfide (the rotten-egg smell) was measured in only 0 Madison County wells, too few to say how common it is. Limited local data (fewer than 20 samples): individual well testing recommended. If you notice the smell, a sulfide test confirms it.
How Madison County Compares to Florida and the U.S.
See How Madison County Compares to Florida & the US
| Share of wells with… | Madison CountyMadison | FloridaFL | United StatesUS |
|---|---|---|---|
| Hard water (above 7 gpg) | 78% | 79% | 60% |
| Iron above 0.3 mg/L | 28% | 35% | 19% |
| Manganese above 0.05 mg/L | 14% | 8% | 21% |
| Dissolved solids above 500 mg/L | 0% | 22% | 15% |
| Acidic water (pH below 6.5) | 12% | 15% | 14% |
| Nitrate above 10 mg/L (EPA limit) | Limited data | 2% | 4% |
| Arsenic above 10 µg/L (EPA limit) | 1% | 3% | 7% |
| Median hardness | 8.6 gpg | 12.4 gpg | — |
| Median pH | 7.3 | 7.2 | 7.3 |
Madison County and Florida: share of sampled wells (all well types, samples since 2000) whose typical value exceeds the level, from the Water Quality Portal. United States: USGS Circular 1332, about 2,100 domestic wells in 48 states sampled 1991 to 2004. Well types and years differ, so read this as a broad comparison. Highlighted cells are well above the national share.
See what a typical Madison County well needs
Opens the diagnostic calculator with Madison County median values (8.6 gpg hardness, 0.07 ppm iron, pH 7.3) for a 3–4 person home. Swap in your own lab results for an exact plan.
Testing Your Well in Madison County
The Florida Department of Health in Madison County oversees private well permitting in the county and investigates suspected contamination. For routine bacteria, nitrate or full-panel tests, use a laboratory certified by the Florida Department of Health.
What to test for in Madison County:
- Bacteria (total coliform and E. coli) and nitrate, at least once a year (Florida Department of Health recommendation)
- Hardness in grains per gallon (gpg) to size a softener
- After any flood, new well work or a change in taste, color or smell
The Florida Department of Health in Madison County can explain how to collect samples and where to send them. Statewide guidance is on the FDOH private well testing page, and our guide to how to test well water covers which tests to order.
Nearby Counties
Madison County borders these counties with published reports:
Frequently Asked Questions
How many homes in Madison County use private wells?
The Florida Department of Health’s Florida Water Management Inventory (2022 data) found 66.9% of built parcels in Madison County on private wells, roughly 4,846 properties.
How hard is well water in Madison County?
Groundwater samples from 86 wells in Madison County have a median hardness of 8.6 grains per gallon (147 mg/L), which the USGS classes as hard. About 78% of sampled wells are above 7 gpg, the point where a water softener is usually worthwhile. The Florida statewide median is 12.4 gpg.
Is iron a problem in Madison County well water?
The median iron level across 76 sampled wells is 0.07 mg/L, below the EPA aesthetic guideline of 0.3 mg/L, and 28% of wells exceed it. Most wells will not stain, but if yours does, a lab test tells you whether iron or manganese is the cause.
Why does my well water smell like rotten eggs in Madison County?
Hydrogen sulfide (the rotten-egg smell) was measured in only 0 Madison County wells, too few to say how common it is. Limited local data (fewer than 20 samples): individual well testing recommended. If you notice the smell, a sulfide test confirms it. The smell is a nuisance rather than a health risk at typical levels.
Which aquifer supplies wells in Madison County?
Most groundwater pumped in Madison County comes from the Floridan Aquifer (USGS, 2015 withdrawals).
Does boiling well water make it safe to drink in Madison County?
Only if bacteria are the problem. A one-minute rolling boil kills germs, but it does not remove nitrate, arsenic or other chemicals, and it concentrates them as water evaporates. Test first, and see our boiling well water myth buster for when boiling helps.
How often should I test my well water in Madison County?
The Florida Department of Health recommends testing private wells for bacteria and nitrate at least once a year, and again after flooding or well repairs. The Florida Department of Health in Madison County can explain how to collect and submit samples.
Written by Well Water Advisor Editorial Team.