Full contaminant data, sample history, and sourcing for Jefferson County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
211 well testing events on record, covering
22 analytes.
Data spans 1959 to 2022.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. OH Avg
Radon
1
2019
100%
240% of limit
↑ 985% above
Manganese
194
1972–2019
97%
470% of limit
↑ 166% above
Iron
194
1972–2019
98%
153% of limit
↓ 65% below
Sulfate
159
1972–2019
100%
44% of limit
~ typical
Lead
123
1972–2019
39%
0% of limit
↓ 100% below
Fluoride
154
1972–2019
99%
5% of limit
↓ 51% below
Chloride
195
1972–2019
100%
14% of limit
~ typical
Arsenic
103
1976–2019
75%
10% of limit
↓ 37% below
HFPO-DA (GenX)
municipal
16
2023–2025
0%
—
—
Nitrate
23
1972–2019
100%
1% of limit
↓ 88% below
Nitrite
12
1973–2019
42%
1% of limit
↑ 57% above
PFHxS
municipal
16
2023–2025
0%
—
—
PFNA
municipal
16
2023–2025
0%
—
—
PFOA
municipal
16
2023–2025
0%
—
—
PFOS
municipal
16
2023–2025
0%
—
—
Uranium
1
2019
100%
0% of limit
↓ 91% below
pH
171
1972–2019
100%
—
~ typical
Sodium
194
1972–2019
100%
—
~ typical
PFBS
municipal
16
2023–2025
19%
—
~ typical
Total Coliform
1
2019
0%
—
—
Hardness
174
1972–2019
100%
—
↓ 27% below
E. coli
1
2019
0%
—
—
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 Jefferson County
Of the 103 arsenic tests on record for Jefferson County (1976–2019),
25% found none.
Of the 195 chloride tests on record for Jefferson County (1972–2019),
0% found none, and half were below 35 mg/L.
Of the 154 fluoride tests on record for Jefferson County (1972–2019),
1% found none, and half were below 200 µg/L.
Of the 194 iron tests on record for Jefferson County (1972–2019),
2% found none, and half were below 420 µg/L.
Of the 123 lead tests on record for Jefferson County (1972–2019),
61% found none.
Of the 194 manganese tests on record for Jefferson County (1972–2019),
3% found none, and half were below 215 µg/L.
Of the 23 nitrate tests on record for Jefferson County (1972–2019),
0% found none, and half were below 60 µg/L.
Of the 159 sulfate tests on record for Jefferson County (1972–2019),
0% found none, and half were below 109 mg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Manganese 194 samples
Iron 194 samples
Sulfate 159 samples
Lead 123 samples
Fluoride 154 samples
Chloride 195 samples
Arsenic 103 samples
Nitrate 23 samples
pH 171 samples
Sodium 194 samples
Hardness 174 samples
Limited data (<15 samples) — interpret with caution
Radon 1 sample
Nitrite 12 samples
Uranium 1 sample
Total Coliform 1 sample
E. coli 1 sample
No private-well PFAS data for Jefferson County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Jefferson County.
PFAS has been detected in local public water systems (UCMR 5 data) — indicated by the "municipal" badge in the table above — but this does not directly indicate private well contamination.
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 Jefferson County
35Active public water systems
58,488Residents on public water
11%Households on private wells
Public water systems in Jefferson 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 Jefferson 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 Jefferson 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 Jefferson County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Jefferson 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 Jefferson County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Jefferson 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.