Data & Methodology — Monroe County

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

Contaminant Data — All Analytes

209 well testing events on record, covering 22 analytes. Data spans 1926 to 2023.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. PA Avg
Manganese 24 1968–2023 88%
100% of limit ↓ 80% below
Radon 6 2000–2023 100%
18% of limit ↓ 86% below
Iron 24 1968–2023 75%
82% of limit ↓ 86% below
PFOS municipal 575 2023–2025 23%
86% of limit ↓ 32% below
PFOA municipal 574 2023–2025 28%
71% of limit ↓ 24% below
Arsenic 8 2000–2023 62%
12% of limit ↓ 59% below
Chloride 28 1930–2023 100%
1% of limit ↓ 89% below
Fluoride 24 1968–2023 75%
2% of limit ↓ 44% below
HFPO-DA (GenX) municipal 432 2023–2025 0%
— —
Lead 14 1974–2023 36%
1% of limit ↓ 81% below
Nitrate 28 1930–2023 100%
3% of limit ↓ 82% below
Nitrite 7 2000–2023 14%
0% of limit ↓ 67% below
PFHxS municipal 72 2023–2025 0%
— —
PFNA municipal 72 2023–2025 0%
— —
Sulfate 28 1930–2023 96%
3% of limit ↓ 81% below
Uranium 7 2000–2023 43%
2% of limit ↓ 28% below
E. coli 2 2000–2023 0%
— —
Hardness 24 1968–2023 100%
— ↓ 78% below
PFBS municipal 432 2023–2025 16%
— ↓ 43% below
pH 27 1968–2023 100%
— ~ typical
Sodium 16 1968–2023 100%
— ↓ 83% below
Total Coliform 2 1972–2023 62%
— ~ 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 PA.

Compare your result with Monroe County

Of the 28 chloride tests on record for Monroe County (1930–2023), 0% found none, and half were below 3 mg/L.

Of the 24 fluoride tests on record for Monroe County (1968–2023), 25% found none, and half were below 100 µg/L.

Of the 24 iron tests on record for Monroe County (1968–2023), 25% found none, and half were below 135 µg/L.

Of the 24 manganese tests on record for Monroe County (1968–2023), 12% found none, and half were below 31.8 µg/L.

Of the 28 nitrate tests on record for Monroe County (1930–2023), 0% found none, and half were below 325 µg/L.

Of the 502 pfoa tests on record for Monroe County (2025), 69% found none.

Of the 503 pfos tests on record for Monroe County (2025), 75% found none.

Of the 28 sulfate tests on record for Monroe County (1930–2023), 4% found none, and half were below 7.62 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Manganese 24 samples
  • Iron 24 samples
  • PFOS 575 samples
  • PFOA 574 samples
  • Chloride 28 samples
  • Fluoride 24 samples
  • HFPO-DA (GenX) 432 samples
  • Nitrate 28 samples
  • Sulfate 28 samples
  • Hardness 24 samples
  • PFBS 432 samples
  • pH 27 samples
  • Sodium 16 samples

Limited data (<15 samples) — interpret with caution

  • Radon 6 samples
  • Arsenic 8 samples
  • Lead 14 samples
  • Nitrite 7 samples
  • Uranium 7 samples
  • E. coli 2 samples
  • Total Coliform 2 samples

Public vs. Private Water in Monroe County

444 Active public water systems
189,005 Residents on public water
60% Households on private wells

Public water systems in Monroe 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 Monroe 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 Monroe County Prevalence PA Average Source Year
PFOA Cancer prevalence 5.8% 7.0% 2020

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