Data & Methodology — Sumter County

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

Contaminant Data — All Analytes

450 well testing events on record, covering 23 analytes. Data spans 1956 to 2025.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. FL Avg
PFOS municipal 36 2023–2025 31%
132% of limit ↓ 37% below
PFOA municipal 36 2023–2025 28%
130% of limit ~ typical
Iron 273 1966–2025 99%
3% of limit ↓ 99% below
PFHxS municipal 36 2023–2025 17%
98% of limit ↑ 90% above
Lead 27 1994–2024 93%
3% of limit ~ typical
Sulfate 356 1966–2025 98%
8% of limit ↓ 71% below
Manganese 252 1992–2025 99%
1% of limit ↓ 97% below
Fluoride 309 1966–2025 98%
3% of limit ↓ 61% below
HFPO-DA (GenX) municipal 36 2023–2025 0%
— —
Nitrite 225 1974–2024 82%
0% of limit ↓ 90% below
Arsenic 27 1994–2024 96%
2% of limit ↓ 81% below
Chloride 355 1966–2025 100%
4% of limit ↓ 92% below
PFNA municipal 36 2023–2025 0%
— —
Radon 3 2002 100%
10% of limit ↓ 66% below
Uranium 4 2002–2010 100%
1% of limit ↓ 21% below
Nitrate 57 1966–2012 49%
3% of limit ~ typical
Hardness 88 1966–2012 100%
— ~ typical
Total Coliform 43 2002–2025 98%
— ~ typical
Sodium 356 1966–2025 100%
— ↓ 92% below
pH 354 1966–2025 100%
— ~ typical
E. coli 20 2002–2025 100%
— ~ typical
Fecal Coliform 23 2013–2021 100%
— ~ typical
PFBS municipal 36 2023–2025 61%
— ↑ 47% above

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 Sumter County

Of the 27 arsenic tests on record for Sumter County (1994–2024), 4% found none, and half were below 0.25 µg/L.

Of the 355 chloride tests on record for Sumter County (1966–2025), 0% found none, and half were below 9.21 mg/L.

Of the 309 fluoride tests on record for Sumter County (1966–2025), 2% found none, and half were below 110 µg/L.

Of the 273 iron tests on record for Sumter County (1966–2025), 1% found none, and half were below 8.5 µg/L.

Of the 27 lead tests on record for Sumter County (1994–2024), 7% found none, and half were below 0.43 µg/L.

Of the 252 manganese tests on record for Sumter County (1992–2025), 1% found none, and half were below 0.43 µg/L.

Of the 57 nitrate tests on record for Sumter County (1966–2012), 51% found none.

Of the 356 sulfate tests on record for Sumter County (1966–2025), 2% found none, and half were below 12.8 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 273 samples
  • Lead 27 samples
  • Sulfate 356 samples
  • Manganese 252 samples
  • Fluoride 309 samples
  • Nitrite 225 samples
  • Arsenic 27 samples
  • Chloride 355 samples
  • Nitrate 57 samples
  • Hardness 88 samples
  • Total Coliform 43 samples
  • Sodium 356 samples
  • pH 354 samples
  • E. coli 20 samples
  • Fecal Coliform 23 samples

Limited data (<15 samples) — interpret with caution

  • Radon 3 samples
  • Uranium 4 samples

No private-well PFAS data for Sumter County

We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Sumter 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 Sumter County

82 Active public water systems
174,314 Residents on public water
16% Households on private wells

Public water systems in Sumter 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 Sumter 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 Sumter County Prevalence FL Average Source Year
Lead Heart disease rate 13.4% 7.7% 2020
PFOA Cancer prevalence 6.0% 6.8% 2020

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