Full contaminant data, sample history, and sourcing for Portage County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
2310 well testing events on record, covering
18 analytes.
Data spans 1965 to 2021.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. OH Avg
Manganese
153
1978–2014
95%
454% of limit
↑ 157% above
Iron
153
1978–2014
92%
460% of limit
~ typical
Chloride
2257
1978–2014
100%
35% of limit
↑ 134% above
Sulfate
107
1978–2014
100%
23% of limit
↓ 48% below
Arsenic
103
1991–2014
71%
0% of limit
↓ 100% below
Lead
112
1991–2014
61%
0% of limit
↓ 100% below
Fluoride
148
1978–2014
61%
4% of limit
↓ 57% below
HFPO-DA (GenX)
municipal
18
2023–2025
0%
—
—
Nitrate
21
1991–1999
95%
10% of limit
↑ 98% above
Nitrite
26
1991–1999
54%
2% of limit
↑ 214% above
PFHxS
municipal
18
2023–2025
0%
—
—
PFNA
municipal
18
2023–2025
0%
—
—
PFOA
municipal
18
2023–2025
0%
—
—
PFOS
municipal
18
2023–2025
0%
—
—
Hardness
127
1978–2014
100%
—
↓ 27% below
PFBS
municipal
18
2023–2025
0%
—
—
pH
763
1978–2011
100%
—
~ typical
Sodium
2002
1978–2014
100%
—
↑ 64% 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.
Compare your result with Portage County
Of the 103 arsenic tests on record for Portage County (1991–2014),
29% found none.
Of the 2257 chloride tests on record for Portage County (1978–2014),
0% found none, and half were below 88.2 mg/L.
Of the 148 fluoride tests on record for Portage County (1978–2014),
39% found none, and half were below 50 µg/L.
Of the 153 iron tests on record for Portage County (1978–2014),
8% found none, and half were below 1.36 mg/L.
Of the 112 lead tests on record for Portage County (1991–2014),
39% found none.
Of the 153 manganese tests on record for Portage County (1978–2014),
5% found none, and half were below 220 µg/L.
Of the 21 nitrate tests on record for Portage County (1991–1999),
5% found none, and half were below 950 µg/L.
Of the 107 sulfate tests on record for Portage County (1978–2014),
0% found none, and half were below 57.6 mg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Manganese 153 samples
Iron 153 samples
Chloride 2257 samples
Sulfate 107 samples
Arsenic 103 samples
Lead 112 samples
Fluoride 148 samples
Nitrate 21 samples
Nitrite 26 samples
Hardness 127 samples
pH 763 samples
Sodium 2002 samples
No private-well PFAS data for Portage County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Portage 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 Portage County
174Active public water systems
127,712Residents on public water
26%Households on private wells
Public water systems in Portage 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 Portage 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 Portage 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 Portage County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Portage 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 Portage County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Portage 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.