Health problems are rare in tested Putnam County wells.

All 5 health checks came back rare here.

From 53 wells tested in Putnam County since 2002; your own well needs its own test. How to read this

Tested wells over the limit PutnamFlorida

Arsenic2%1 of 53 Lead0%0 of 51 Nitrate0%0 of 45 Fluoride0%0 of 24 Manganese0%0 of 53

GermsTest every year, whatever the chart says

Coliform bacteria44%7 of 16 E. coli0%0 of 9

StainsNot a health risk

Iron stains51%27 of 53

Not charted, because fewer than 10 wells were tested: uranium (2), radon (2).

Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+

Lab results: Water Quality Portal (USGS and EPA)

Show bacteria and iron

Who drinks from a well here

7 in 10 people 49,014 people

Nobody else tests these wells. Only you do.

People on wells: EPA researchers' 2020 estimate

Radon risk (a gas from rock)

LowMiddleHigh

Less likely, but the EPA still says test your air.

Radon zones: EPA map

Here's how Putnam County compares with Florida and the counties around it.

Each result puts Putnam County next to the 7 counties that border it, on the chart's 0 to 50% scale.

All 5 health checks are rare in Putnam County.

Arsenic1 of 53 wells over

1 of 53 wells tested here from 2002 to 2025 was over the EPA limit of 10 µg/L, against about 1 in 9 across Florida. That's a smaller share than in 35 of the 63 other Florida counties with 10 or more tested wells.

Putnam and its neighbors

Bradford46%

Alachua15%

Clay8%

Flagler3%

Putnam2%

St. Johns2%

Volusia2%

Marion0%

Arsenic guide

Lead0 of 51 wells over

None of the 51 wells tested here from 2002 to 2025 were over the EPA action level of 15 µg/L, against about 1 in 9 across Florida. At least half the results were too low for the lab to measure, and the top 1 in 10 were 0.62 µg/L or more. Putnam County had none, while 35 of the 63 other Florida counties with 10 or more tested wells had at least one.

Putnam and its neighbors

Bradford44%

Alachua16%

Flagler3%

Volusia2%

St. Johns2%

Clay1%

Marion1%

Putnam0%

Lead guide

Nitrate0 of 45 wells over

None of the 45 wells tested here from 2002 to 2026 were over the EPA limit of 10 mg/L, against about 1 in 32 across Florida. At least half the results were too low for the lab to measure, and the top 1 in 10 were 0.061 mg/L or more. Putnam County had none, while 25 of the 59 other Florida counties with 10 or more tested wells had at least one.

Putnam and its neighbors

Alachua12%

Bradford8%

Marion3%

Clay0%

Flagler0%

Putnam0%

St. Johns0%

Volusia0%

Nitrate guide

Fluoride0 of 24 wells over

None of the 24 wells tested here from 2002 to 2026 were over the EPA limit of 4 mg/L, against under 1 in 50 across Florida. Half the results were under 0.21 mg/L, and the top 1 in 10 were 0.23 mg/L or more. Putnam County had none, while 16 of the 63 other Florida counties with 10 or more tested wells had at least one.

Putnam and its neighbors

Bradford17%

Alachua7%

Clay0%

Flagler0%

Marion0%

Putnam0%

St. Johns0%

Volusia0%

Manganese0 of 53 wells over

None of the 53 wells tested here from 2002 to 2025 were over the EPA health advisory of 0.3 mg/L, against under 1 in 100 across Florida. At least half the results were too low for the lab to measure, and the top 1 in 10 were 0.029 mg/L or more. Putnam County had none, while 15 of the 63 other Florida counties with 10 or more tested wells had at least one.

Putnam and its neighbors

Marion4%

Alachua2%

St. Johns2%

Clay1%

Bradford0%

Flagler0%

Putnam0%

Volusia0%

Manganese guide

Too few Putnam County wells were tested for these 2.

Uranium2 wells tested

Only 2 wells here were tested in 2002, too few to say how common it is. Across Florida it's under 1 in 100.

Uranium guide

Radon in water2 wells tested

Only 2 wells here were tested in 2002, too few to say how common it is. Across Florida it's about 1 in 45.

Radon guide

Coliform bacteria turned up in 7 of 16 tested Putnam County wells, so test for it every year.

Coliform bacteria7 of 16 wells had it

About 4 in 10 wells tested here from 2017 to 2026 had coliform bacteria, against about 5 in 10 across Florida.

Putnam and its neighbors

Marion58%

Volusia49%

St. Johns48%

Alachua44%

Flagler44%

Putnam44%

Clay29%

Too few tested to show: Bradford.

Most of Florida's bacteria results come from shallow monitoring-network wells, so they aren't a guide to household wells.

Bacteria guide

E. coli0 of 9 wells had it

None of the 9 wells tested here from 2021 to 2026 had E. coli, against about 1 in 12 across Florida.

E. coli means human or animal waste is getting in, so if a test of your Putnam County well finds it, boil drinking water until the well is fixed.

Bacteria guide

Iron reached staining levels in 27 of 53 tested wells, and it isn't a health risk.

Iron stains27 of 53 wells had it

About 5 in 10 wells tested here from 2002 to 2025 had enough iron to stain (0.3 mg/L), against about 4 in 10 across Florida.

Putnam and its neighbors

Bradford66%

Flagler56%

Putnam51%

Clay51%

Volusia49%

St. Johns44%

Alachua37%

Marion20%

Iron guide

About 7 in 10 of the 53 wells tested in Putnam County have a test from 2020 or later.

13 wells had a test in the 2000s, 32 in the 2010s and 38 since 2020.

With 38 wells tested since 2020, age matters less here than who did the testing and why.

Most Putnam County wells in these records were tested for research or because someone suspected a problem, which can push the shares above what a typical home well would show (how we read the numbers).

One mail-in lab test covers the 3 things to check in Putnam County.

Bacteria
Nitrate
Arsenic

What Florida offers well owners

Free testingSome county health departments may test for certain toxic substances free of charge. See the program
Certified labsFlorida's list of certified labs
Well recordsWe didn't find an online search.
New wellsNo statewide rule. We didn't find a local rule for Putnam County, so ask its health department.

Here's what we know about radon and PFAS in Putnam County.

Putnam County is in the EPA's lowest radon zone, so radon from well water is unlikely to be a problem. Radon guide

Between 2023 and 2025 the EPA had 3 town water systems in Putnam County test for PFAS. None found any. No well in Putnam County has public PFAS results, so the town systems are the best clue to what's in the groundwater nearby. PFAS guide

Radon zones: EPA Map of Radon Zones. PFAS: EPA tests of town water systems, 2023 to 2025

Next door to Putnam County

Marion Volusia Clay Alachua St. Johns

Elsewhere in Florida

Duval Brevard Hillsborough

All of Florida

Questions people ask about well water in Putnam County

Is well water in Putnam County safe to drink?

Most tested wells in Putnam County came in under the limits. Of 5 health checks with enough tests, arsenic came closest, at 1 of 53 wells over. Every well is different, so test yours for bacteria, nitrate and arsenic.

Can I get my well tested for free in Putnam County?

Some county health departments may test for certain toxic substances free of charge. If not, use a lab Florida has certified for drinking water. Ask for bacteria, nitrate and arsenic, the tests that matter most in Putnam County.

How does Putnam County compare with the counties around it?

For arsenic, the share of tested wells over the limit: 4 of the 7 neighboring counties with data had a higher share than Putnam County, at 2%. Bradford had the most, at 46%. Groundwater doesn't stop at county lines, so Bradford's 46% is worth knowing about if you live near it.

How often should I test my well in Putnam County?

In Putnam County, 7 of 16 tested wells had coliform bacteria, so the CDC's advice matters here: test for bacteria and nitrate every year, and right away after a flood, a repair, or any change in taste or smell.

By the Tested Water teamData from the USGS, EPA and Department of HealthUpdated November 8, 2026

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Where the Putnam County numbers come from

People on wells: 49,014 in Putnam County, from EPA estimates built on the 2020 Census (Murray et al.).
Lab tests: 1,111 well water samples from 53 wells in the Water Quality Portal, run by the USGS and EPA, 2002 to 2026.
Neighboring counties: the 7 counties that share a border with Putnam County, from the Census Bureau's county adjacency file.
PFAS: EPA tests of 3 town water systems in Putnam County under the Fifth Unregulated Contaminant Monitoring Rule, 2023 to 2025.
Radon: Putnam County is zone 3 on the EPA Map of Radon Zones.
State programs and links: Department of Health, checked November 1, 2026.

Download this county's data (CSV)How we read these numbers Report an error