Data & Methodology — Hernando County

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

Contaminant Data — All Analytes

1836 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
Radon 1 2015 100%
157% of limit ↑ 434% above
Chloride 1693 1962–2025 100%
10% of limit ↓ 80% below
PFOS municipal 37 2023–2025 30%
160% of limit ↓ 24% below
Sulfate 1160 1962–2025 100%
5% of limit ↓ 81% below
Iron 1008 1962–2025 99%
6% of limit ↓ 97% below
Arsenic 34 1977–2024 97%
2% of limit ↓ 81% below
PFOA municipal 37 2023–2025 8%
110% of limit ↓ 23% below
Manganese 909 1977–2025 99%
4% of limit ↓ 84% below
Uranium 3 2002–2015 100%
4% of limit ↑ 261% above
Lead 37 1977–2024 78%
1% of limit ↓ 58% below
Nitrate 17 1962–2015 100%
1% of limit ↓ 60% below
PFHxS municipal 37 2023–2025 3%
33% of limit ↓ 36% below
Fluoride 931 1962–2025 99%
2% of limit ↓ 68% below
HFPO-DA (GenX) municipal 37 2023–2025 0%
— —
Nitrite 475 1971–2024 99%
0% of limit ↓ 90% below
PFNA municipal 37 2023–2025 0%
— —
Total Coliform 49 1985–2025 97%
— ~ typical
Hardness 120 1962–2015 100%
— ↓ 36% below
pH 969 1962–2025 100%
— ~ typical
Sodium 1058 1962–2025 100%
— ↓ 87% below
PFBS municipal 37 2023–2025 49%
— ~ typical
Fecal Coliform 29 1985–2021 96%
— ~ typical
E. coli 20 2002–2025 96%
— ~ 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 Hernando County

Of the 34 arsenic tests on record for Hernando County (1977–2024), 3% found none, and half were below 0.25 µg/L.

Of the 1693 chloride tests on record for Hernando County (1962–2025), 0% found none, and half were below 24.2 mg/L.

Of the 931 fluoride tests on record for Hernando County (1962–2025), 1% found none, and half were below 90 µg/L.

Of the 1008 iron tests on record for Hernando County (1962–2025), 1% found none, and half were below 15.7 µg/L.

Of the 37 lead tests on record for Hernando County (1977–2024), 22% found none, and half were below 0.2 µg/L.

Of the 909 manganese tests on record for Hernando County (1977–2025), 1% found none, and half were below 2.02 µg/L.

Of the 1160 sulfate tests on record for Hernando County (1962–2025), 0% found none, and half were below 12.3 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Chloride 1693 samples
  • Sulfate 1160 samples
  • Iron 1008 samples
  • Arsenic 34 samples
  • Manganese 909 samples
  • Lead 37 samples
  • Nitrate 17 samples
  • Fluoride 931 samples
  • Nitrite 475 samples
  • Total Coliform 49 samples
  • Hardness 120 samples
  • pH 969 samples
  • Sodium 1058 samples
  • Fecal Coliform 29 samples
  • E. coli 20 samples

Limited data (<15 samples) — interpret with caution

  • Radon 1 sample
  • Uranium 3 samples

No private-well PFAS data for Hernando County

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

113 Active public water systems
178,191 Residents on public water
22% Households on private wells

Public water systems in Hernando 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 Hernando 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 Hernando County Prevalence FL Average Source Year
Arsenic Cancer prevalence 8.9% 6.8% 2020
Arsenic Kidney disease rate 4.1% 3.4% 2020

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