Data & Methodology — Pasco County

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

Contaminant Data — All Analytes

1854 well testing events on record, covering 23 analytes. Data spans 1923 to 2024.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. FL Avg
Radon 8 2002–2015 100%
540% of limit ↑ 1741% above
PFOS municipal 84 2023–2025 44%
212% of limit ~ typical
Iron 747 1962–2025 97%
59% of limit ↓ 71% below
Chloride 1781 1962–2025 100%
23% of limit ↓ 53% below
PFOA municipal 84 2023–2025 20%
340% of limit ↑ 138% above
Sulfate 875 1962–2025 98%
5% of limit ↓ 80% below
Manganese 512 1973–2025 99%
24% of limit ~ typical
PFHxS municipal 84 2023–2025 24%
67% of limit ↑ 31% above
Nitrate 237 1962–2015 51%
0% of limit ↓ 97% below
Arsenic 108 1973–2024 95%
8% of limit ↓ 39% below
Fluoride 569 1962–2025 95%
3% of limit ↓ 61% below
Lead 109 1973–2024 37%
1% of limit ↓ 58% below
Uranium 26 2002–2015 96%
1% of limit ↑ 26% above
PFNA municipal 84 2023–2025 2%
58% of limit ~ typical
HFPO-DA (GenX) municipal 84 2023–2025 0%
— —
Nitrite 391 1971–2024 60%
0% of limit ↓ 90% below
pH 690 1962–2025 100%
— ~ typical
Sodium 785 1962–2025 100%
— ↓ 88% below
PFBS municipal 84 2023–2025 45%
— ↑ 34% above
Fecal Coliform 14 1985–2021 88%
— ~ typical
E. coli 10 2002–2024 89%
— ~ typical
Total Coliform 24 1985–2024 86%
— ~ typical
Hardness 319 1962–2015 100%
— ↓ 28% below

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 Pasco County

Of the 108 arsenic tests on record for Pasco County (1973–2024), 5% found none, and half were below 0.8 µg/L.

Of the 1781 chloride tests on record for Pasco County (1962–2025), 0% found none, and half were below 57 mg/L.

Of the 569 fluoride tests on record for Pasco County (1962–2025), 5% found none, and half were below 110 µg/L.

Of the 747 iron tests on record for Pasco County (1962–2025), 3% found none, and half were below 157 µg/L.

Of the 109 lead tests on record for Pasco County (1973–2024), 63% found none.

Of the 512 manganese tests on record for Pasco County (1973–2025), 1% found none, and half were below 11.9 µg/L.

Of the 237 nitrate tests on record for Pasco County (1962–2015), 49% found none.

Of the 875 sulfate tests on record for Pasco County (1962–2025), 2% found none, and half were below 12 mg/L.

Of the 26 uranium tests on record for Pasco County (2002–2015), 4% found none, and half were below 0.341 µg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 747 samples
  • Chloride 1781 samples
  • Sulfate 875 samples
  • Manganese 512 samples
  • Nitrate 237 samples
  • Arsenic 108 samples
  • Fluoride 569 samples
  • Lead 109 samples
  • Uranium 26 samples
  • Nitrite 391 samples
  • pH 690 samples
  • Sodium 785 samples
  • Total Coliform 24 samples
  • Hardness 319 samples

Limited data (<15 samples) — interpret with caution

  • Radon 8 samples
  • Fecal Coliform 14 samples
  • E. coli 10 samples

No private-well PFAS data for Pasco County

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

211 Active public water systems
413,624 Residents on public water
16% Households on private wells

Public water systems in Pasco 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 Pasco 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 Pasco County Prevalence FL Average Source Year
Arsenic Cancer prevalence 5.9% 6.8% 2020
Arsenic Kidney disease rate 2.8% 3.4% 2020

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