Data & Methodology — Indiana County

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

Contaminant Data — All Analytes

516 well testing events on record, covering 20 analytes. Data spans 1959 to 2018.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. PA Avg
Manganese 460 1964–2003 60%
450% of limit ~ typical
Iron 462 1964–2003 68%
132% of limit ↓ 77% below
Radon 13 1995–2014 100%
7% of limit ↓ 95% below
PFOS municipal 68 2023–2025 10%
200% of limit ↑ 57% above
Sulfate 462 1964–2003 100%
9% of limit ↓ 49% below
Lead 457 1964–2003 2%
133% of limit ↑ 2783% above
Arsenic 455 1986–2003 9%
0% of limit ↓ 100% below
Nitrate 459 1964–2014 70%
3% of limit ↓ 83% below
Chloride 461 1964–2003 100%
2% of limit ↓ 78% below
Fluoride 456 1964–2003 96%
1% of limit ↓ 72% below
HFPO-DA (GenX) municipal 57 2023–2025 0%
— —
Nitrite 26 1995–2014 12%
1% of limit ↓ 33% below
PFHxS municipal 15 2023–2025 0%
— —
PFNA municipal 15 2023–2025 0%
— —
PFOA municipal 68 2023–2025 10%
69% of limit ↓ 26% below
Uranium 23 1996–2003 57%
1% of limit ↓ 42% below
Sodium 458 1964–2003 100%
— ↓ 76% below
pH 466 1964–2015 100%
— ~ typical
PFBS municipal 57 2023–2025 4%
— ↓ 79% below
Hardness 461 1964–2003 100%
— ↓ 40% 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 PA.

Compare your result with Indiana County

Of the 455 arsenic tests on record for Indiana County (1986–2003), 91% found none.

Of the 461 chloride tests on record for Indiana County (1964–2003), 0% found none, and half were below 6 mg/L.

Of the 456 fluoride tests on record for Indiana County (1964–2003), 4% found none, and half were below 50 µg/L.

Of the 462 iron tests on record for Indiana County (1964–2003), 32% found none, and half were below 160 µg/L.

Of the 457 lead tests on record for Indiana County (1964–2003), 98% found none.

Of the 460 manganese tests on record for Indiana County (1964–2003), 40% found none, and half were below 60 µg/L.

Of the 459 nitrate tests on record for Indiana County (1964–2014), 30% found none, and half were below 100 µg/L.

Of the 53 pfoa tests on record for Indiana County (2025), 87% found none.

Of the 53 pfos tests on record for Indiana County (2025), 87% found none.

Of the 462 sulfate tests on record for Indiana County (1964–2003), 0% found none, and half were below 22 mg/L.

Of the 23 uranium tests on record for Indiana County (1996–2003), 43% found none, and half were below 0.1 µg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Manganese 460 samples
  • Iron 462 samples
  • PFOS 68 samples
  • Sulfate 462 samples
  • Lead 457 samples
  • Arsenic 455 samples
  • Nitrate 459 samples
  • Chloride 461 samples
  • Fluoride 456 samples
  • HFPO-DA (GenX) 57 samples
  • Nitrite 26 samples
  • PFOA 68 samples
  • Uranium 23 samples
  • Sodium 458 samples
  • pH 466 samples
  • PFBS 57 samples
  • Hardness 461 samples

Limited data (<15 samples) — interpret with caution

  • Radon 13 samples

Public vs. Private Water in Indiana County

53 Active public water systems
54,205 Residents on public water
48% Households on private wells

Public water systems in Indiana 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 Indiana 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 Indiana County Prevalence PA Average Source Year
Lead Heart disease rate 6.5% 7.2% 2020
Arsenic Cancer prevalence 6.1% 7.0% 2020
Arsenic Kidney disease rate 2.8% 3.0% 2020

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