Full contaminant data, sample history, and sourcing for Putnam County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
367 well testing events on record, covering
23 analytes.
Data spans 1956 to 2023.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. FL Avg
Iron
333
1989–2024
93%
57% of limit
↓ 72% below
Chloride
362
1980–2025
100%
4% of limit
↓ 92% below
Manganese
309
1989–2024
90%
7% of limit
↓ 73% below
Arsenic
218
2002–2024
100%
5% of limit
↓ 62% below
Sulfate
282
1980–2025
99%
1% of limit
↓ 95% below
PFOS
municipal
5
2023–2025
0%
—
—
PFNA
municipal
5
2023–2025
0%
—
—
PFOA
municipal
5
2023–2025
0%
—
—
Fluoride
167
1980–2025
93%
1% of limit
↓ 87% below
HFPO-DA (GenX)
municipal
5
2023–2025
0%
—
—
Nitrite
13
1980–2002
23%
0% of limit
↓ 84% below
PFHxS
municipal
5
2023–2025
0%
—
—
Lead
219
1980–2024
100%
0% of limit
↓ 89% below
Nitrate
13
1980–2002
62%
0% of limit
↓ 87% below
Radon
3
1993–2002
100%
6% of limit
↓ 80% below
Uranium
3
1993–2002
67%
0% of limit
↓ 62% below
Hardness
118
1980–2004
100%
—
↓ 98% below
Total Coliform
46
1980–2025
100%
—
~ typical
E. coli
22
2021–2025
100%
—
~ typical
Fecal Coliform
24
2017–2021
100%
—
~ typical
PFBS
municipal
5
2023–2025
0%
—
—
Sodium
357
1980–2025
100%
—
↓ 91% below
pH
352
1980–2025
100%
—
~ typical
Distribution shows the share of samples in each concentration band relative to the EPA Maximum Contaminant Level (MCL): Low = below half the MCL, Moderate = between half and the MCL, High = above the MCL. Analytes without an MCL (e.g. sodium, pH) show — in the limit columns. State average is based on county median values across FL.
Compare your result with Putnam County
Of the 218 arsenic tests on record for Putnam County (2002–2024),
0% found none, and half were below 0.5 µg/L.
Of the 362 chloride tests on record for Putnam County (1980–2025),
0% found none, and half were below 10.3 mg/L.
Of the 167 fluoride tests on record for Putnam County (1980–2025),
7% found none, and half were below 30.8 µg/L.
Of the 333 iron tests on record for Putnam County (1989–2024),
7% found none, and half were below 49.7 µg/L.
Of the 219 lead tests on record for Putnam County (1980–2024),
0% found none, and half were below 50 ng/L.
Of the 309 manganese tests on record for Putnam County (1989–2024),
10% found none, and half were below 3 µg/L.
Of the 282 sulfate tests on record for Putnam County (1980–2025),
1% found none, and half were below 3 mg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Iron 333 samples
Chloride 362 samples
Manganese 309 samples
Arsenic 218 samples
Sulfate 282 samples
Fluoride 167 samples
Lead 219 samples
Hardness 118 samples
Total Coliform 46 samples
E. coli 22 samples
Fecal Coliform 24 samples
Sodium 357 samples
pH 352 samples
Limited data (<15 samples) — interpret with caution
Nitrite 13 samples
Nitrate 13 samples
Radon 3 samples
Uranium 3 samples
No private-well PFAS data for Putnam County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Putnam County.
PFAS testing for private wells requires a dedicated lab panel (~$300–$500). If you are near a military base, airport, or industrial site, consider testing proactively. Learn more about PFAS →
Public vs. Private Water in Putnam County
113Active public water systems
33,215Residents on public water
72%Households on private wells
Public water systems in Putnam County are regulated by the EPA and must test and report contaminant levels. Private well owners are responsible for their own testing — there is no routine monitoring of private wells by any government agency.
CDC Health Outcome Correlations
Where contaminants detected in Putnam County have established associations with specific health outcomes, we cross-reference CDC PLACES county-level prevalence data. This is a contextual signal, not a causal claim.
This report aggregates data from the following public databases:
Water Quality Portal (WQP) — groundwater sample results for Putnam County from EPA, USGS, and state agencies. Browse WQP data →
EPA Safe Drinking Water Information System (SDWIS) — public water system inventory used to estimate the share of residents on private wells. Browse SDWIS →
Census ACS 5-Year Estimates — well and cistern household counts (variable DP04_0074E) used to calculate the private-well percentage for Putnam County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Putnam County, which informs which contaminants are geologically likely. USGS Aquifer Atlas →
EPA UCMR 5 (2023–2025) — PFAS occurrence data from public water systems, used as a proxy indicator for aquifer PFAS exposure. Rows marked "municipal" in the table above come from this source. About UCMR 5 →
EPA Toxics Release Inventory (TRI) — industrial facility chemical releases near Putnam County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Putnam County, used in contamination risk scoring. Superfund site search →
CDC PLACES — county-level health outcome prevalence (kidney disease, cancer, heart disease) correlated with detected contaminants. About CDC PLACES →
Methodology
Raw records are downloaded from the Water Quality Portal and normalized to µg/L (ppb). Records are deduplicated by sample ID and date, and certified outliers are excluded. Analyte names are mapped to EPA canonical forms. Detection rates, distribution bands, and MCL comparisons are computed from the normalized dataset.
Distribution bands use the EPA Maximum Contaminant Level as the threshold: concentrations below 50% of the MCL are classed as Low, between 50% and 100% as Moderate, and above 100% as High. For analytes without an MCL (sodium, hardness, pH), distribution is not computed.
State comparison uses the median of county median values across all counties in FL with at least one sample for that analyte.