How hard is the water in Nassau County, FL?
17.2 grains per gallon
A softener will pay its way here.
The median hardness measured in Nassau County, FL is 294 mg/L as calcium carbonate, which is 17.2 gpg. That is very hard on the USGS scale. It comes from 45 samples at 6 sites between 1990 and 2024, drawn from groundwater wells, which is what most taps and private wells in the county draw on.
How much it varies here
Half the sites came in between 17.1 and 19.8 gpg. The whole middle of that range gives the same answer, so a test of your own tap is unlikely to change it. Confidence in the county figure: medium (how it is measured).
What to do next
At 17.2 gpg a softener pays its way here. Before you buy, check the quoted unit's grain capacity against the sizing table below, and ask whether it regenerates on demand, which uses less salt than a timer. Call your utility for its own report if you are on city water.
More on sizing a softener for your household.
From 15.8 to 28.1 gpg
The softest single sample on record in Nassau County was 270 mg/L and the hardest 481 mg/L, a 2-fold gap. The top quarter of sites read above 19.8 gpg and the bottom quarter below 17.1 gpg.
Wells 17.2 gpg, rivers and lakes 58.5 gpg
45 groundwater samples from 6 wells put the median at 294 mg/L. 346 surface samples from 31 sites put it at 1001 mg/L. In Nassau County the rivers and lakes come out 41.3 gpg harder. Here the surface water reads harder than the wells, which often points to streams fed by limestone springs or irrigation return flow. A utility here that draws from the aquifer can deliver noticeably different water from a private well next door.
What a softener would cost to run
For a household of 3, a 24,000-grain unit covers a week between regenerations. Expect about 375 lb of salt a year (10 bags of 40 lb, about $68), and roughly 2,346 gallons of regeneration water. Installed, most units run $1,000 to $4,500; spread over 15 years with salt, that is about $168 a year.
Sizing at 17.2 gpg
| People | Grains a day | Unit | Salt a year |
|---|---|---|---|
| 1 | 1,032 | 24,000 | 126 lb |
| 2 | 2,064 | 24,000 | 251 lb |
| 4 | 4,128 | 32,000 | 502 lb |
| 6 | 6,192 | 48,000 | 753 lb |
Nassau County against the rest of Florida
Among the 67 Florida counties with data, Nassau County is number 15 of 67 counting from the hardest. Across the whole country it is harder than 76% of counties.
Softest in Florida: Washington County at 0.3 gpg. Hardest: Sarasota County at 32.2 gpg. Closest to Nassau County: Broward County (17.2), Hendry County (17.4), Palm Beach County (17.7).