Full contaminant data, sample history, and sourcing for Erie County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
412 well testing events on record, covering
23 analytes.
Data spans 1951 to 2023.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. NY Avg
Manganese
189
1951–2021
79%
130% of limit
↓ 58% below
Iron
197
1951–2021
56%
85% of limit
↓ 56% below
Radon
29
2006–2021
100%
52% of limit
↓ 53% below
Sulfate
273
1951–2021
100%
13% of limit
~ typical
Chloride
295
1951–2023
100%
11% of limit
↓ 64% below
Lead
186
1971–2021
17%
9% of limit
↑ 126% above
Nitrate
190
1951–2021
71%
15% of limit
↑ 27% above
Arsenic
170
1971–2021
20%
3% of limit
↓ 83% below
Fluoride
189
1951–2021
65%
5% of limit
~ typical
HFPO-DA (GenX)
municipal
38
2023–2025
0%
—
—
Nitrite
178
1971–2021
12%
2% of limit
↑ 144% above
PFHxS
municipal
38
2023–2025
0%
—
—
PFNA
municipal
38
2023–2025
0%
—
—
PFOA
municipal
38
2023–2025
0%
—
—
PFOS
municipal
38
2023–2025
0%
—
—
Uranium
32
2004–2021
59%
0% of limit
↓ 73% below
Total Coliform
15
2006–2021
21%
—
~ typical
Sodium
209
1951–2021
100%
—
↓ 64% below
pH
370
1951–2021
100%
—
~ typical
PFBS
municipal
38
2023–2025
0%
—
—
Hardness
288
1951–2021
100%
—
↑ 42% above
Fecal Coliform
15
2006–2021
3%
—
~ typical
E. coli
15
2006–2021
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 NY.
Compare your result with Erie County
Of the 170 arsenic tests on record for Erie County (1971–2021),
80% found none.
Of the 295 chloride tests on record for Erie County (1951–2023),
0% found none, and half were below 26 mg/L.
Of the 189 fluoride tests on record for Erie County (1951–2021),
35% found none, and half were below 200 µg/L.
Of the 197 iron tests on record for Erie County (1951–2021),
44% found none, and half were below 50 µg/L.
Of the 186 lead tests on record for Erie County (1971–2021),
83% found none.
Of the 189 manganese tests on record for Erie County (1951–2021),
21% found none, and half were below 40 µg/L.
Of the 190 nitrate tests on record for Erie County (1951–2021),
29% found none, and half were below 370 µg/L.
Of the 273 sulfate tests on record for Erie County (1951–2021),
0% found none, and half were below 33 mg/L.
Of the 32 uranium tests on record for Erie County (2004–2021),
41% found none, and half were below 72 ng/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Manganese 189 samples
Iron 197 samples
Radon 29 samples
Sulfate 273 samples
Chloride 295 samples
Lead 186 samples
Nitrate 190 samples
Arsenic 170 samples
Fluoride 189 samples
Nitrite 178 samples
Uranium 32 samples
Total Coliform 15 samples
Sodium 209 samples
pH 370 samples
Hardness 288 samples
Fecal Coliform 15 samples
E. coli 15 samples
No private-well PFAS data for Erie County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Erie 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 →
CDC Health Outcome Correlations
Where contaminants detected in Erie 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 Erie 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 Erie County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Erie 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 Erie County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Erie 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 NY with at least one sample for that analyte.