Data & Methodology — Lawrence County

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

Contaminant Data — All Analytes

100 well testing events on record, covering 20 analytes. Data spans 1926 to 2025.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. PA Avg
Radon 1 2015 100%
160% of limit ↑ 24% above
Iron 47 1928–2023 100%
533% of limit ~ typical
Manganese 42 1957–2023 98%
308% of limit ↓ 39% below
PFOS municipal 88 2023–2025 8%
92% of limit ↓ 28% below
Chloride 46 1928–2023 100%
2% of limit ↓ 83% below
Arsenic 18 2015–2023 56%
5% of limit ↓ 81% below
Fluoride 42 1957–2023 98%
4% of limit ↓ 22% below
HFPO-DA (GenX) municipal 60 2023–2025 0%
— —
Lead 19 1966–2023 11%
1% of limit ↓ 69% below
Nitrate 47 1928–2023 62%
0% of limit ↓ 97% below
Nitrite 18 2015–2023 0%
— —
PFHxS municipal 12 2023–2024 0%
— —
PFNA municipal 12 2023–2024 0%
— —
PFOA municipal 88 2023–2025 8%
60% of limit ↓ 36% below
Sulfate 46 1928–2023 100%
15% of limit ~ typical
Uranium 12 2015–2021 0%
— —
pH 46 1957–2023 100%
— ~ typical
PFBS municipal 60 2023–2025 18%
— ↓ 38% below
Sodium 47 1928–2023 100%
— ↓ 35% below
Hardness 47 1928–2023 100%
— ↑ 32% above

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 Lawrence County

Of the 46 chloride tests on record for Lawrence County (1928–2023), 0% found none, and half were below 4.6 mg/L.

Of the 42 fluoride tests on record for Lawrence County (1957–2023), 2% found none, and half were below 140 µg/L.

Of the 47 iron tests on record for Lawrence County (1928–2023), 0% found none, and half were below 1.6 mg/L.

Of the 42 manganese tests on record for Lawrence County (1957–2023), 2% found none, and half were below 152 µg/L.

Of the 47 nitrate tests on record for Lawrence County (1928–2023), 38% found none, and half were below 20 µg/L.

Of the 76 pfoa tests on record for Lawrence County (2025), 91% found none.

Of the 76 pfos tests on record for Lawrence County (2025), 91% found none.

Of the 46 sulfate tests on record for Lawrence County (1928–2023), 0% found none, and half were below 37 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 47 samples
  • Manganese 42 samples
  • PFOS 88 samples
  • Chloride 46 samples
  • Arsenic 18 samples
  • Fluoride 42 samples
  • HFPO-DA (GenX) 60 samples
  • Lead 19 samples
  • Nitrate 47 samples
  • Nitrite 18 samples
  • PFOA 88 samples
  • Sulfate 46 samples
  • pH 46 samples
  • PFBS 60 samples
  • Sodium 47 samples
  • Hardness 47 samples

Limited data (<15 samples) — interpret with caution

  • Radon 1 sample
  • Uranium 12 samples

Public vs. Private Water in Lawrence County

64 Active public water systems
75,839 Residents on public water
43% Households on private wells

Public water systems in Lawrence 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 Lawrence 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 Lawrence County Prevalence PA Average Source Year
Lead Heart disease rate 8.8% 7.2% 2020
PFOS Cancer prevalence 8.3% 7.0% 2020

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