Data & Methodology — Hancock County

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

Contaminant Data — All Analytes

52 well testing events on record, covering 19 analytes. Data spans 1965 to 2024.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. OH Avg
Sulfate 10 1973–2014 100%
127% of limit ↑ 119% above
Iron 44 1973–2014 95%
131% of limit ↓ 76% below
Manganese 37 1973–2014 95%
18% of limit ↓ 96% below
Lead 33 1975–2014 73%
0% of limit ↓ 100% below
Arsenic 35 1976–2014 74%
0% of limit ↓ 100% below
Chloride 46 1973–2014 98%
13% of limit ↓ 70% below
Fluoride 32 1973–2014 100%
40% of limit ↑ 140% above
HFPO-DA (GenX) municipal 4 2023–2024 0%
— —
Nitrate 15 1973–1992 93%
0% of limit ↓ 95% below
Nitrite 2 1992 50%
0% of limit ↓ 97% below
PFHxS municipal 4 2023–2024 0%
— —
PFNA municipal 4 2023–2024 0%
— —
PFOA municipal 4 2023–2024 0%
— —
PFOS municipal 4 2023–2024 0%
— —
Radon 2 1992 100%
16% of limit ↓ 81% below
Sodium 48 1973–2014 100%
— ↓ 46% below
pH 38 1973–2004 100%
— ~ typical
PFBS municipal 4 2023–2024 0%
— —
Hardness 34 1973–2014 100%
— ↑ 221% 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 OH.

Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 44 samples
  • Manganese 37 samples
  • Lead 33 samples
  • Arsenic 35 samples
  • Chloride 46 samples
  • Fluoride 32 samples
  • Nitrate 15 samples
  • Sodium 48 samples
  • pH 38 samples
  • Hardness 34 samples

Limited data (<15 samples) — interpret with caution

  • Sulfate 10 samples
  • Nitrite 2 samples
  • Radon 2 samples

No private-well PFAS data for Hancock County

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

41 Active public water systems
67,543 Residents on public water
10% Households on private wells

Public water systems in Hancock 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 Hancock 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 Hancock County Prevalence OH Average Source Year
Radon Cancer prevalence 7.3% 6.8% 2020
Lead Heart disease rate 7.6% 7.6% 2020

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

Last updated: 2026-07-15

Full methodology →