Full contaminant data, sample history, and sourcing for Preble County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
142 well testing events on record, covering
20 analytes.
Data spans 1962 to 2020.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. OH Avg
Iron
125
1986–2020
92%
483% of limit
~ typical
Manganese
126
1986–2020
89%
58% of limit
↓ 67% below
Arsenic
127
1986–2020
89%
40% of limit
↑ 154% above
Lead
126
1986–2020
66%
0% of limit
↓ 100% below
Chloride
123
1986–2020
100%
11% of limit
↓ 30% below
Fluoride
108
1996–2020
100%
22% of limit
↑ 119% above
HFPO-DA (GenX)
municipal
7
2025
0%
—
—
Nitrate
47
1986–2020
21%
7% of limit
↑ 35% above
Nitrite
45
1991–2020
24%
1% of limit
~ typical
PFHxS
municipal
7
2025
0%
—
—
PFNA
municipal
7
2025
0%
—
—
PFOA
municipal
7
2025
0%
—
—
PFOS
municipal
7
2025
0%
—
—
Radon
3
1999–2000
100%
7% of limit
↓ 70% below
Sulfate
48
1998–2020
94%
12% of limit
↓ 73% below
Uranium
32
1999–2020
97%
2% of limit
~ typical
Hardness
119
1986–2020
100%
—
~ typical
PFBS
municipal
7
2025
0%
—
—
pH
123
1986–2020
100%
—
~ typical
Sodium
125
1986–2020
100%
—
↓ 53% 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 Preble County
Of the 127 arsenic tests on record for Preble County (1986–2020),
11% found none, and half were below 3.5 µg/L.
Of the 123 chloride tests on record for Preble County (1986–2020),
0% found none, and half were below 26.5 mg/L.
Of the 108 fluoride tests on record for Preble County (1996–2020),
0% found none, and half were below 900 µg/L.
Of the 125 iron tests on record for Preble County (1986–2020),
8% found none, and half were below 1.12 mg/L.
Of the 126 lead tests on record for Preble County (1986–2020),
34% found none.
Of the 126 manganese tests on record for Preble County (1986–2020),
11% found none, and half were below 24.4 µg/L.
Of the 47 nitrate tests on record for Preble County (1986–2020),
79% found none.
Of the 48 sulfate tests on record for Preble County (1998–2020),
6% found none, and half were below 24.9 mg/L.
Of the 32 uranium tests on record for Preble County (1999–2020),
3% found none, and half were below 0.58 µg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Iron 125 samples
Manganese 126 samples
Arsenic 127 samples
Lead 126 samples
Chloride 123 samples
Fluoride 108 samples
Nitrate 47 samples
Nitrite 45 samples
Sulfate 48 samples
Uranium 32 samples
Hardness 119 samples
pH 123 samples
Sodium 125 samples
Limited data (<15 samples) — interpret with caution
Radon 3 samples
No private-well PFAS data for Preble County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Preble 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 Preble County
30Active public water systems
28,413Residents on public water
50%Households on private wells
Public water systems in Preble 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 Preble 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 Preble 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 Preble County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Preble 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 Preble County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Preble 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.