Typical values from 188 sampled wells in Polk County · Full groundwater profile
What Are You Noticing in Your Water?
Pre-selected from Polk 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 Polk County and nearby counties
Most homes in Polk County, in Central Florida, are on public water, but about one in twelve still are not: 8.4% of built parcels, roughly 21,524 properties, draw drinking water from an onsite private well, according to the Florida Department of Health’s 2023 inventory.
Polk County includes part of the Green Swamp, one of the most important recharge areas for the Floridan Aquifer, and the headwaters of the Peace River. That geology shapes which well water problems show up most often here.
In this guide
Groundwater Profile: Polk County
Most groundwater pumped in Polk County comes from the Floridan Aquifer (USGS, 2015 withdrawals). Across 188 sampled wells, the median hardness is 9 gpg, which the USGS classes as hard. It applies to wells across Polk County, including around Lakeland, Winter Haven and Haines City.
What shows up in local well samples:
- HardnessMedian 9 gpg; 67% of 188 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 sulfideLimited local data (fewer than 20 samples): individual well testing recommended.
Causes a rotten-egg smell, usually from low-oxygen groundwater, often stronger in hot water.
Sulfur treatment guide
How Polk County Compares to Florida and the U.S.
See How Polk County Compares to Florida & the US
| Share of wells with… | Polk CountyPolk | FloridaFL | United StatesUS |
|---|---|---|---|
| Hard water (above 7 gpg) | 67% | 79% | 60% |
| Iron above 0.3 mg/L | 25% | 35% | 19% |
| Manganese above 0.05 mg/L | 13% | 8% | 21% |
| Dissolved solids above 500 mg/L | 11% | 22% | 15% |
| Acidic water (pH below 6.5) | 19% | 15% | 14% |
| Nitrate above 10 mg/L (EPA limit) | 0% | 2% | 4% |
| Arsenic above 10 µg/L (EPA limit) | 1% | 3% | 7% |
| Median hardness | 9 gpg | 12.4 gpg | — |
| Median pH | 7.4 | 7.2 | 7.3 |
Polk 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 Polk County well needs
Opens the diagnostic calculator with Polk County median values (9 gpg hardness, 0.03 ppm iron, pH 7.4) for a 3–4 person home. Swap in your own lab results for an exact plan.
Testing Your Well in Polk County
The Florida Department of Health in Polk County oversees private and limited-use water systems and well permitting, and collects and evaluates water samples when contamination is suspected. For routine testing, use an FDOH-certified commercial lab.
For nitrates, metals, or a full panel, use a laboratory certified by the Florida Department of Health. The state’s private well water testing guide explains which tests to order and how to find a certified lab near you.
What to test for in Polk 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
- Hydrogen sulfide if you notice a rotten-egg smell
- After any flood, new well work or a change in taste, color or smell
The Florida Department of Health in Polk 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
Polk County borders these counties with published reports:
Frequently Asked Questions
How hard is well water in Polk County?
Groundwater samples from 188 wells in Polk County have a median hardness of 9 grains per gallon (153 mg/L), which the USGS classes as hard. About 67% 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 Polk County well water?
The median iron level across 187 sampled wells is 0.03 mg/L, below the EPA aesthetic guideline of 0.3 mg/L, and 25% 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 Polk County?
Hydrogen sulfide (the rotten-egg smell) was measured in only 17 Polk 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 Polk County?
Most groundwater pumped in Polk County comes from the Floridan Aquifer (USGS, 2015 withdrawals).
Does boiling well water make it safe to drink in Polk 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 many homes in Polk County use private wells?
The Florida Department of Health’s 2023 Florida Water Management Inventory found 8.4% of built parcels in Polk County on private wells, roughly 21,524 properties. Most of the county’s built parcels are served by public water systems; private wells are most common on rural lots and older properties outside utility service areas.
Where can I get my well water tested in Polk County?
Routine bacteria and nitrate tests are done through FDOH-certified commercial labs. DOH-Polk’s drinking water program handles well permitting and investigates suspected contamination.
Do I need to test my well water if my neighbors say theirs is fine?
Yes. Well depth, casing condition, and the exact aquifer layer tapped can vary block to block, so one neighbor’s clean test does not guarantee another’s. A full annual test is the only reliable way to know what is in your own water.
Is Floridan Aquifer water generally safe to drink untreated?
Much of it is chemically safe but aesthetically unpleasant (hard, sulfur-smelling, or iron-stained), which is why treatment here is usually about comfort and plumbing protection rather than an acute health risk. A lab test is still the only way to rule out bacteria, nitrates, or other contaminants specific to your well.
Written by Well Water Advisor Editorial Team.