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Manganese in Florida well water, by county

By the Tested Water teamLab data from the USGS and EPA Water Quality Portal, 2000 to 2026Updated November 8, 2026

Manganese is rare in tested Florida wells: in all 64 counties with enough tests, fewer than 5% of tested wells were over the limit. A county's share tells you how likely a problem is nearby. Only a test of your own well tells you what's in it.

Find a manganese test See every county

How Florida compares with the rest of the country

Across Florida, under 1 in 50 tested wells had manganese over the EPA health advisory of 0.3 mg/L (34 of 3,750). Across all tested wells in the US it's about 1 in 7. That's less often than in the country as a whole. Counties still differ, so check yours below.

Why it matters: High levels over many years may affect the nervous system, and babies are more sensitive to it. It also leaves black stains.

Manganese dissolves out of rock and soil, especially in water with little oxygen.

Manganese in tested wells, county by county

Share of each county's tested wells with at least one result over the EPA health advisory of 0.3 mg/L. Counties need 10 or more tested wells to be listed. Widespread means 15% or more, worth checking 5 to 15%, rare under 5%.

CountyWells testedWells over the limitLevel
Marion County 173
4% 7 of 173
 Rare
Duval County 116
3% 4 of 116
 Rare
Pasco County 67
3% 2 of 67
 Rare
Okeechobee County 37
3% 1 of 37
 Rare
Alachua County 84
2% 2 of 84
 Rare
Polk County 177
2% 4 of 177
 Rare
Broward County 50
2% 1 of 50
 Rare
Collier County 276
2% 5 of 276
 Rare
St. Johns County 59
2% 1 of 59
 Rare
Clay County 75
1% 1 of 75
 Rare
Suwannee County 77
1% 1 of 77
 Rare
Hillsborough County 159
1% 2 of 159
 Rare
Citrus County 83
1% 1 of 83
 Rare
Palm Beach County 96
1% 1 of 96
 Rare
Miami-Dade County 142
1% 1 of 142
 Rare
Volusia County 128
0% 0 of 128
 Rare
Lake County 109
0% 0 of 109
 Rare
Sarasota County 91
0% 0 of 91
 Rare
Levy County 85
0% 0 of 85
 Rare
Orange County 78
0% 0 of 78
 Rare
Manatee County 70
0% 0 of 70
 Rare
Hernando County 63
0% 0 of 63
 Rare
Seminole County 63
0% 0 of 63
 Rare
DeSoto County 61
0% 0 of 61
 Rare
Lee County 61
0% 0 of 61
 Rare
Brevard County 54
0% 0 of 54
 Rare
Jackson County 54
0% 0 of 54
 Rare
Putnam County 53
0% 0 of 53
 Rare
Columbia County 52
0% 0 of 52
 Rare
Taylor County 47
0% 0 of 47
 Rare
Charlotte County 44
0% 0 of 44
 Rare
Gilchrist County 44
0% 0 of 44
 Rare
Madison County 44
0% 0 of 44
 Rare
Walton County 43
0% 0 of 43
 Rare
Santa Rosa County 40
0% 0 of 40
 Rare
Osceola County 38
0% 0 of 38
 Rare
Bay County 37
0% 0 of 37
 Rare
Hendry County 37
0% 0 of 37
 Rare
Lafayette County 37
0% 0 of 37
 Rare
Indian River County 36
0% 0 of 36
 Rare
Leon County 36
0% 0 of 36
 Rare
Martin County 36
0% 0 of 36
 Rare
Highlands County 35
0% 0 of 35
 Rare
Pinellas County 34
0% 0 of 34
 Rare
Nassau County 33
0% 0 of 33
 Rare
Okaloosa County 33
0% 0 of 33
 Rare
Flagler County 32
0% 0 of 32
 Rare
Escambia County 30
0% 0 of 30
 Rare
Hamilton County 30
0% 0 of 30
 Rare
Wakulla County 30
0% 0 of 30
 Rare
Hardee County 29
0% 0 of 29
 Rare
Dixie County 25
0% 0 of 25
 Rare
St. Lucie County 25
0% 0 of 25
 Rare
Sumter County 25
0% 0 of 25
 Rare
Jefferson County 23
0% 0 of 23
 Rare
Baker County 22
0% 0 of 22
 Rare
Gulf County 21
0% 0 of 21
 Rare
Gadsden County 19
0% 0 of 19
 Rare
Union County 18
0% 0 of 18
 Rare
Washington County 14
0% 0 of 14
 Rare
Bradford County 13
0% 0 of 13
 Rare
Holmes County 11
0% 0 of 11
 Rare
Calhoun County 10
0% 0 of 10
 Rare
Glades County 10
0% 0 of 10
 Rare

3 more Florida counties have 1 to 9 tested wells for manganese, too few to rate.

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Where to get your well tested for manganese in Florida

1

Free testing, with limits

Some Florida county health departments may test for certain chemicals for free, so call yours first. Check which tests it includes before you count on it for manganese.

Florida's private well page
2

A lab Florida certifies

Ask for manganese by name. Results from a certified lab count for a home sale or a loan.

Labs certified by Florida
3

A mail-in kit

Fill the bottles at your kitchen tap and mail them back. We mark the kits that include manganese.

Compare kits

Keep reading about wells in Florida

Questions people ask about manganese in Florida

Is there manganese in Florida well water?

Manganese is rare in tested Florida wells: in all 64 counties with enough tests, fewer than 5% of tested wells were over the limit. Across Florida, under 1 in 50 tested wells had manganese over the EPA health advisory of 0.3 mg/L (34 of 3,750). Across all tested wells in the US it's about 1 in 7. That's less often than in the country as a whole. Counties still differ, so check yours below.

Where can I get my well tested for manganese in Florida?

Some Florida county health departments may test for certain chemicals for free, so call yours first. If that doesn't cover you, use a lab certified by Florida for drinking water, or a mail-in kit that includes manganese from a certified lab.

See Florida's list of certified labs, or compare mail-in kits.

Where these numbers come from

  • Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000. A well counts as over if any of its tests was over the EPA health advisory of 0.3 mg/L. Wells tested for studies and monitoring, not a random sample of homes.
  • Likely overstated: our own check of who tested the wells, when and where. How we check.
  • State programs and links: Department of Health.