Data & Methodology — Leon County

Full contaminant data, sample history, and sourcing for Leon County. For readers who want to go beyond the summary.

Contaminant Data — All Analytes

1397 well testing events on record, covering 23 analytes. Data spans 1957 to 2024.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. FL Avg
Iron 317 1973–2025 74%
14% of limit ↓ 93% below
Manganese 336 1972–2025 51%
40% of limit ↑ 51% above
Nitrate 963 1972–2015 95%
8% of limit ↑ 159% above
PFOS municipal 70 2023–2025 7%
198% of limit ~ typical
Arsenic 343 1972–2025 44%
10% of limit ↓ 23% below
Sulfate 594 1972–2025 97%
2% of limit ↓ 93% below
Nitrite 976 1972–2015 55%
1% of limit ~ typical
Chloride 1213 1972–2025 100%
2% of limit ↓ 95% below
PFNA municipal 70 2023–2025 0%
— —
PFOA municipal 70 2023–2025 0%
— —
Fluoride 585 1972–2025 81%
2% of limit ↓ 65% below
HFPO-DA (GenX) municipal 70 2023–2025 0%
— —
PFHxS municipal 70 2023–2025 4%
35% of limit ↓ 32% below
Lead 337 1972–2025 23%
1% of limit ↓ 58% below
Radon 2 1993–2015 100%
34% of limit ~ typical
Uranium 5 1993–2015 80%
2% of limit ↑ 86% above
Hardness 552 1973–2015 97%
— ↓ 53% below
Total Coliform 67 1980–2025 34%
— ~ typical
Sodium 789 1973–2025 100%
— ↓ 95% below
E. coli 37 2015–2025 97%
— ~ typical
Fecal Coliform 30 1980–2021 16%
— ~ typical
PFBS municipal 70 2023–2025 1%
— ↓ 34% below
pH 1124 1971–2025 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 Leon County

Of the 343 arsenic tests on record for Leon County (1972–2025), 56% found none.

Of the 1213 chloride tests on record for Leon County (1972–2025), 0% found none, and half were below 5.6 mg/L.

Of the 585 fluoride tests on record for Leon County (1972–2025), 19% found none, and half were below 100 µg/L.

Of the 317 iron tests on record for Leon County (1973–2025), 26% found none, and half were below 30 µg/L.

Of the 337 lead tests on record for Leon County (1972–2025), 77% found none.

Of the 336 manganese tests on record for Leon County (1972–2025), 49% found none, and half were below 0.75 µg/L.

Of the 963 nitrate tests on record for Leon County (1972–2015), 5% found none, and half were below 690 µg/L.

Of the 594 sulfate tests on record for Leon County (1972–2025), 3% found none, and half were below 4.7 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 317 samples
  • Manganese 336 samples
  • Nitrate 963 samples
  • Arsenic 343 samples
  • Sulfate 594 samples
  • Nitrite 976 samples
  • Chloride 1213 samples
  • Fluoride 585 samples
  • Lead 337 samples
  • Hardness 552 samples
  • Total Coliform 67 samples
  • Sodium 789 samples
  • E. coli 37 samples
  • Fecal Coliform 30 samples
  • pH 1124 samples

Limited data (<15 samples) — interpret with caution

  • Radon 2 samples
  • Uranium 5 samples

No private-well PFAS data for Leon County

We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Leon County. PFAS has been detected in local public water systems (UCMR 5 data) — indicated by the "municipal" badge in the table above — but this does not directly indicate private well contamination. 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 Leon County

41 Active public water systems
236,457 Residents on public water
16% Households on private wells

Public water systems in Leon 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 Leon 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.

Contaminant Associated Condition Leon County Prevalence FL Average Source Year
Arsenic Cancer prevalence 5.9% 6.8% 2020
Arsenic Kidney disease rate 2.9% 3.4% 2020

Source: CDC PLACES county-level estimates. Raw data: Download Leon County CDC PLACES data →

Data Sources

This report aggregates data from the following public databases:

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.

Last updated: 2026-08-12

Full methodology →