Data & Methodology — Lake County

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

Contaminant Data — All Analytes

712 well testing events on record, covering 23 analytes. Data spans 1948 to 2017.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. FL Avg
PFOS municipal 83 2023–2025 43%
150% of limit ↓ 29% below
Iron 630 1968–2025 99%
7% of limit ↓ 96% below
PFOA municipal 83 2023–2025 20%
128% of limit ~ typical
Chloride 655 1968–2025 100%
5% of limit ↓ 90% below
Manganese 580 1977–2025 99%
6% of limit ↓ 79% below
Nitrate 35 1968–2015 60%
4% of limit ~ typical
Sulfate 578 1968–2025 98%
4% of limit ↓ 85% below
PFHxS municipal 83 2023–2025 39%
37% of limit ↓ 28% below
Arsenic 576 1977–2025 97%
5% of limit ↓ 62% below
Lead 579 1977–2025 96%
0% of limit ↓ 89% below
Fluoride 129 1968–2025 83%
3% of limit ↓ 59% below
HFPO-DA (GenX) municipal 83 2023–2025 0%
— —
Nitrite 33 1972–2015 39%
2% of limit ↑ 92% above
PFNA municipal 83 2023–2025 1%
40% of limit ↓ 31% below
Radon 3 2002–2015 100%
16% of limit ↓ 44% below
Uranium 3 2002–2015 67%
1% of limit ↓ 27% below
Sodium 655 1968–2025 100%
— ↓ 91% below
pH 660 1968–2025 100%
— ~ typical
Hardness 58 1968–2015 100%
— ↓ 44% below
Total Coliform 44 1973–2025 98%
— ~ typical
E. coli 19 2015–2025 95%
— ~ typical
Fecal Coliform 25 1977–2021 100%
— ~ typical
PFBS municipal 83 2023–2025 42%
— ~ 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 Lake County

Of the 576 arsenic tests on record for Lake County (1977–2025), 3% found none, and half were below 0.5 µg/L.

Of the 655 chloride tests on record for Lake County (1968–2025), 0% found none, and half were below 11.8 mg/L.

Of the 129 fluoride tests on record for Lake County (1968–2025), 17% found none, and half were below 100 µg/L.

Of the 630 iron tests on record for Lake County (1968–2025), 1% found none, and half were below 21.7 µg/L.

Of the 579 lead tests on record for Lake County (1977–2025), 4% found none, and half were below 50 ng/L.

Of the 580 manganese tests on record for Lake County (1977–2025), 1% found none, and half were below 2.64 µg/L.

Of the 35 nitrate tests on record for Lake County (1968–2015), 40% found none, and half were below 10 µg/L.

Of the 578 sulfate tests on record for Lake County (1968–2025), 2% found none, and half were below 9.75 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 630 samples
  • Chloride 655 samples
  • Manganese 580 samples
  • Nitrate 35 samples
  • Sulfate 578 samples
  • Arsenic 576 samples
  • Lead 579 samples
  • Fluoride 129 samples
  • Nitrite 33 samples
  • Sodium 655 samples
  • pH 660 samples
  • Hardness 58 samples
  • Total Coliform 44 samples
  • E. coli 19 samples
  • Fecal Coliform 25 samples

Limited data (<15 samples) — interpret with caution

  • Radon 3 samples
  • Uranium 3 samples

No private-well PFAS data for Lake County

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

274 Active public water systems
431,469 Residents on public water
23% Households on private wells

Public water systems in Lake 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 Lake 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 Lake County Prevalence FL Average Source Year
Arsenic Cancer prevalence 8.7% 6.8% 2020
Arsenic Kidney disease rate 3.8% 3.4% 2020
Lead Heart disease rate 6.1% 7.7% 2020

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