Full contaminant data, sample history, and sourcing for Geauga County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
232 well testing events on record, covering
19 analytes.
Data spans 1974 to 2024.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. OH Avg
Iron
218
1974–2016
94%
117% of limit
↓ 73% below
Manganese
213
1977–2016
91%
108% of limit
↓ 39% below
Arsenic
103
1978–2016
82%
7% of limit
↓ 53% below
Chloride
224
1974–2016
100%
5% of limit
↓ 64% below
Lead
96
1975–2016
69%
0% of limit
↓ 100% below
Sulfate
157
1978–2016
99%
16% of limit
↓ 64% below
Fluoride
188
1974–2016
86%
6% of limit
↓ 44% below
HFPO-DA (GenX)
municipal
6
2024–2025
0%
—
—
Nitrate
64
1974–2016
36%
9% of limit
↑ 91% above
Nitrite
57
1993–2016
16%
0% of limit
↓ 53% below
PFHxS
municipal
6
2024–2025
0%
—
—
PFNA
municipal
6
2024–2025
0%
—
—
PFOA
municipal
6
2024–2025
0%
—
—
PFOS
municipal
6
2024–2025
0%
—
—
Uranium
1
2016
0%
—
—
Sodium
226
1974–2016
100%
—
↓ 39% below
pH
202
1974–2016
100%
—
~ typical
PFBS
municipal
6
2024–2025
0%
—
—
Hardness
215
1974–2016
99%
—
↓ 46% 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 Geauga County
Of the 103 arsenic tests on record for Geauga County (1978–2016),
18% found none.
Of the 224 chloride tests on record for Geauga County (1974–2016),
0% found none, and half were below 13.7 mg/L.
Of the 188 fluoride tests on record for Geauga County (1974–2016),
14% found none, and half were below 200 µg/L.
Of the 218 iron tests on record for Geauga County (1974–2016),
6% found none, and half were below 303 µg/L.
Of the 96 lead tests on record for Geauga County (1975–2016),
31% found none.
Of the 213 manganese tests on record for Geauga County (1977–2016),
9% found none, and half were below 48 µg/L.
Of the 64 nitrate tests on record for Geauga County (1974–2016),
64% found none.
Of the 157 sulfate tests on record for Geauga County (1978–2016),
1% found none, and half were below 39 mg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Iron 218 samples
Manganese 213 samples
Arsenic 103 samples
Chloride 224 samples
Lead 96 samples
Sulfate 157 samples
Fluoride 188 samples
Nitrate 64 samples
Nitrite 57 samples
Sodium 226 samples
pH 202 samples
Hardness 215 samples
Limited data (<15 samples) — interpret with caution
Uranium 1 sample
No private-well PFAS data for Geauga County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Geauga 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 Geauga County
261Active public water systems
68,320Residents on public water
76%Households on private wells
Public water systems in Geauga 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 Geauga 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.
This report aggregates data from the following public databases:
Water Quality Portal (WQP) — groundwater sample results for Geauga County from EPA, USGS, and state agencies. Browse WQP data →
EPA Safe Drinking Water Information System (SDWIS) — public water system inventory used to estimate the share of residents on private wells. Browse SDWIS →
Census ACS 5-Year Estimates — well and cistern household counts (variable DP04_0074E) used to calculate the private-well percentage for Geauga County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Geauga County, which informs which contaminants are geologically likely. USGS Aquifer Atlas →
EPA UCMR 5 (2023–2025) — PFAS occurrence data from public water systems, used as a proxy indicator for aquifer PFAS exposure. Rows marked "municipal" in the table above come from this source. About UCMR 5 →
EPA Toxics Release Inventory (TRI) — industrial facility chemical releases near Geauga County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Geauga County, used in contamination risk scoring. Superfund site search →
CDC PLACES — county-level health outcome prevalence (kidney disease, cancer, heart disease) correlated with detected contaminants. About CDC PLACES →
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.