Typical values from 168 sampled wells in Duval County · Full groundwater profile
What Duval County Wells Usually Need
Very hard water: 10.6 gpg. At 10.6 grains per gallon, well water in Duval County is very hard by USGS standards.
Drink it untreated? Most sampled wells meet health limits; a yearly test confirms yours does.
What a typical home here installs:
- A spin-down or cartridge sediment filter first, so sand and scale do not foul the stages after it.
- A 24,000-grain water softener for a family of four at 10.6 gpg (includes 5 gpg per ppm of iron).
See the right order for these stages. Your own test result decides the final list.
Not sure what to install? Get a filter recommendation for Duval County homesNot on a well? Tap water from a utility is covered by its yearly water quality report (CCR), not by these well samples. Find your utility's report
On this page (7 sections)
Well Water Testing in Duval County: Who to Call
- Florida Department of Health in Duval County, Environmental Health and Safety: 904-253-1282, 921 N. Davis St., Building B, Suite 350, Jacksonville, FL 32209. Drinking water program page
- Certified labs: how to find a state-certified lab (FDOH)
Contacts as listed on the official page, checked November 2026. Call before you go; hours and fees change.
What Are You Noticing in Your Water?
Pre-selected from Duval County well data. Untick anything you do not notice in your own water.
Confirm with a lab test before buying equipment.
Explore Florida Interactive Map
Explore Duval County and nearby counties
Nearly all homes in Duval County, in Northeast Florida, are on public water. The Florida Department of Health's 2022 inventory counts 4.6% of built parcels, roughly 15,480 properties, on private wells, mostly on rural lots outside utility service areas.
Most groundwater pumped in Duval County comes from the Floridan Aquifer (USGS, 2015 withdrawals). Samples from 168 local wells put the median hardness at 10.6 gpg (very hard) and median iron at 0.03 mg/L. The county's largest communities are Jacksonville, Jacksonville Beach and Atlantic Beach.
In this guide
Groundwater Profile: Duval County
Across 168 sampled wells, the median hardness is 10.6 gpg (very hard). At 10.6 gpg, Duval wells run harder than Clay (4.8 gpg), softer than Nassau (17.1 gpg) and St. Johns (23.2 gpg) and about as hard as Baker (10.7 gpg) next door.
Another address? Check hardness by ZIP code.
What shows up in local well samples:
- HardnessMedian 10.6 gpg; 64% of 168 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
How Duval County Compares to Florida and the U.S.
See How Duval County Compares to Florida & the US
| Share of wells with… | Duval CountyDuval | FloridaFL | United StatesUS |
|---|---|---|---|
| Hard water (above 7 gpg) | 64% | 79% | 60% |
| Iron above 0.3 mg/L | 26% | 35% | 19% |
| Manganese above 0.05 mg/L | 19% | 8% | 21% |
| Dissolved solids above 500 mg/L | 20% | 22% | 15% |
| Acidic water (pH below 6.5) | 41% | 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 | 10.6 gpg | 12.4 gpg | — |
| Median pH | 6.7 | 7.2 | 7.3 |
Sources: Water Quality Portal (since 2000); US: USGS Circular 1332. Highlighted: well above the US share.
See what a typical Duval County well needs
Pre-filled with the Duval medians. Swap in your own results.
Testing Your Well in Duval County
The Florida Department of Health in Duval 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 Duval 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
Which tests to order and how: how to test well water.
After a positive coliform test, work out the bleach dose and shock the well and retest 10 to 14 days later.
Nearby Counties
Duval County borders these counties with published reports:
Baker County
10.7 gpg hardness · HardnessClay County
4.8 gpg hardnessNassau County
17.1 gpg hardness · HardnessSt. Johns County
23.2 gpg hardness · Hardness, Chloride (salinity)Counties with similar well water
Farther away, these Florida counties share the same main water issues:
Frequently Asked Questions
Is well water in Duval County safe to drink?
Generally yes in the records: health limits are rarely exceeded in the 168 Duval wells sampled. The common problems here (hardness) affect taste, stains and plumbing, not health. Bacteria and nitrate can still turn up in any well, so test once a year.
How many homes in Duval County use private wells?
The Florida Department of Health’s Florida Water Management Inventory (2022 data) found 4.6% of built parcels in Duval County on private wells, roughly 15,480 properties.
How hard is well water in Duval County?
Very hard. The median Duval well tests at 10.6 grains per gallon across 168 sampled wells (Florida median: 12.4 gpg), and 64% are above the 7 gpg mark where most homes add a softener.
Is iron a problem in Duval County well water?
Usually not. Across 124 sampled wells the median is 0.03 mg/L, under the 0.3 mg/L stain threshold, though 26% of wells exceed it. If your fixtures stain, test for iron and manganese before buying a filter.
Why does my well water smell like rotten eggs in Duval County?
The data cannot say: just 0 Duval wells were tested for hydrogen sulfide. If your water smells, test for sulfide, and if the smell is only in hot water, check the water heater anode rod. It is unpleasant but rarely a health risk.
Does boiling well water make it safe to drink in Duval County?
Boiling handles bacteria and nothing else. It does not soften Duval water, remove iron or take out nitrate, which ends up more concentrated. Read when boiling helps and when it hurts.
How often should I test my well water in Duval 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 Duval County can explain how to collect and submit samples.
Written by Well Water Advisor Editorial Team.