Data & Methodology — Ross County

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

Contaminant Data — All Analytes

116 well testing events on record, covering 18 analytes. Data spans 1965 to 2024.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. OH Avg
Iron 103 1973–2014 86%
490% of limit ~ typical
Manganese 95 1976–2014 85%
218% of limit ↑ 23% above
Lead 90 1975–2014 74%
0% of limit ↓ 100% below
Arsenic 85 1986–2014 79%
30% of limit ↑ 90% above
Chloride 104 1973–2014 100%
10% of limit ↓ 34% below
Fluoride 84 1973–2014 85%
6% of limit ↓ 39% below
HFPO-DA (GenX) municipal 8 2023–2025 0%
— —
Nitrate 21 1973–1991 90%
4% of limit ~ typical
Nitrite 3 1974–1991 33%
1% of limit ~ typical
PFHxS municipal 8 2023–2025 0%
— —
PFNA municipal 10 2008–2025 0%
— —
PFOA municipal 10 2008–2025 0%
— —
PFOS municipal 9 2008–2025 0%
— —
Sulfate 20 1978–2014 100%
14% of limit ↓ 67% below
Hardness 73 1978–2014 100%
— ~ typical
PFBS municipal 8 2023–2025 12%
— ↓ 29% below
pH 60 1973–2005 100%
— ~ typical
Sodium 105 1973–2014 100%
— ↓ 64% 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 OH.

Compare your result with Ross County

Of the 85 arsenic tests on record for Ross County (1986–2014), 21% found none.

Of the 104 chloride tests on record for Ross County (1973–2014), 0% found none, and half were below 25 mg/L.

Of the 84 fluoride tests on record for Ross County (1973–2014), 15% found none, and half were below 215 µg/L.

Of the 103 iron tests on record for Ross County (1973–2014), 14% found none, and half were below 1.43 mg/L.

Of the 90 lead tests on record for Ross County (1975–2014), 26% found none.

Of the 95 manganese tests on record for Ross County (1976–2014), 15% found none, and half were below 94 µg/L.

Of the 21 nitrate tests on record for Ross County (1973–1991), 10% found none, and half were below 400 µg/L.

Of the 20 sulfate tests on record for Ross County (1978–2014), 0% found none, and half were below 35.9 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 103 samples
  • Manganese 95 samples
  • Lead 90 samples
  • Arsenic 85 samples
  • Chloride 104 samples
  • Fluoride 84 samples
  • Nitrate 21 samples
  • Sulfate 20 samples
  • Hardness 73 samples
  • pH 60 samples
  • Sodium 105 samples

Limited data (<15 samples) — interpret with caution

  • Nitrite 3 samples
  • PFNA 10 samples
  • PFOA 10 samples
  • PFOS 9 samples

Public vs. Private Water in Ross County

9 Active public water systems
69,697 Residents on public water
25% Households on private wells

Public water systems in Ross 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 Ross 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 Ross County Prevalence OH Average Source Year
Lead Heart disease rate 7.3% 7.6% 2020

Source: CDC PLACES county-level estimates. Raw data: Download Ross 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: 2026-08-04

Full methodology →