Data & Methodology — Venango County

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

Contaminant Data — All Analytes

86 well testing events on record, covering 22 analytes. Data spans 1928 to 2023.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. PA Avg
Iron 25 1928–2023 96%
38% of limit ↓ 93% below
Radon 3 1997–2019 100%
41% of limit ↓ 69% below
Manganese 23 1964–2023 91%
17% of limit ↓ 97% below
Sulfate 24 1928–2023 100%
2% of limit ↓ 88% below
PFOS municipal 88 2023–2025 12%
84% of limit ↓ 34% below
Arsenic 19 1997–2023 37%
5% of limit ↓ 83% below
Chloride 24 1928–2023 100%
1% of limit ↓ 91% below
Fluoride 22 1964–2023 27%
2% of limit ↓ 44% below
HFPO-DA (GenX) municipal 74 2023–2025 1%
7% of limit ↓ 69% below
Lead 21 1964–2023 81%
3% of limit ↓ 38% below
Nitrate 24 1928–2023 88%
6% of limit ↓ 66% below
Nitrite 20 1975–2023 0%
— —
PFHxS municipal 9 2023–2025 0%
— —
PFNA municipal 9 2023–2025 0%
— —
PFOA municipal 88 2023–2025 12%
57% of limit ↓ 38% below
Uranium 14 1997–2021 7%
1% of limit ↓ 71% below
E. coli 1 2019 0%
— —
Hardness 25 1928–2023 100%
— ↓ 94% below
PFBS municipal 74 2023–2025 11%
— ↓ 37% below
pH 25 1964–2023 100%
— ↓ 27% below
Sodium 23 1964–2023 100%
— ↓ 91% below
Total Coliform 1 2019 0%
— —

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 PA.

Compare your result with Venango County

Of the 24 chloride tests on record for Venango County (1928–2023), 0% found none, and half were below 2.45 mg/L.

Of the 22 fluoride tests on record for Venango County (1964–2023), 73% found none.

Of the 25 iron tests on record for Venango County (1928–2023), 4% found none, and half were below 110 µg/L.

Of the 21 lead tests on record for Venango County (1964–2023), 19% found none, and half were below 0.26 µg/L.

Of the 23 manganese tests on record for Venango County (1964–2023), 9% found none, and half were below 8.67 µg/L.

Of the 24 nitrate tests on record for Venango County (1928–2023), 12% found none, and half were below 555 µg/L.

Of the 79 pfoa tests on record for Venango County (2025), 86% found none.

Of the 79 pfos tests on record for Venango County (2025), 86% found none.

Of the 24 sulfate tests on record for Venango County (1928–2023), 0% found none, and half were below 5.2 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 25 samples
  • Manganese 23 samples
  • Sulfate 24 samples
  • PFOS 88 samples
  • Arsenic 19 samples
  • Chloride 24 samples
  • Fluoride 22 samples
  • HFPO-DA (GenX) 74 samples
  • Lead 21 samples
  • Nitrate 24 samples
  • Nitrite 20 samples
  • PFOA 88 samples
  • Hardness 25 samples
  • PFBS 74 samples
  • pH 25 samples
  • Sodium 23 samples

Limited data (<15 samples) — interpret with caution

  • Radon 3 samples
  • Uranium 14 samples
  • E. coli 1 sample
  • Total Coliform 1 sample

Public vs. Private Water in Venango County

69 Active public water systems
42,478 Residents on public water
38% Households on private wells

Public water systems in Venango 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 Venango 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 Venango County Prevalence PA Average Source Year
PFOS Cancer prevalence 8.6% 7.0% 2020
Lead Heart disease rate 6.5% 7.2% 2020

Source: CDC PLACES county-level estimates. Raw data: Download Venango 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 PA with at least one sample for that analyte.

Last updated: 2026-08-04

Full methodology →