Full contaminant data, sample history, and sourcing for Windham County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
17 well testing events on record, covering
21 analytes.
Data spans 1952 to 2025.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. VT Avg
Manganese
926
1980–2017
100%
6% of limit
↓ 99% below
Iron
767
1980–2017
100%
17% of limit
↓ 92% below
Lead
2550
2017
100%
13% of limit
↓ 81% below
Chloride
1095
1980–2017
100%
1% of limit
↓ 88% below
Arsenic
1185
2017
35%
20% of limit
↓ 61% below
Uranium
1092
2017
45%
3% of limit
↓ 59% below
Nitrate
1050
1994–2017
100%
2% of limit
↓ 24% below
Fluoride
1636
1980–2017
100%
4% of limit
~ typical
HFPO-DA (GenX)
municipal
15
2024–2025
0%
—
—
Nitrite
1034
1994–2017
100%
2% of limit
~ typical
PFHxS
municipal
15
2024–2025
0%
—
—
PFNA
municipal
15
2024–2025
0%
—
—
PFOA
municipal
15
2024–2025
0%
—
—
PFOS
municipal
15
2024–2025
0%
—
—
Sulfate
7
1980–2017
100%
5% of limit
~ typical
Sodium
763
1980–2017
100%
—
↓ 60% below
Total Coliform
1
2017
0%
—
—
E. coli
1
2017
98%
—
↓ 96% below
Hardness
537
1980–2017
100%
—
↓ 28% below
PFBS
municipal
15
2024–2025
0%
—
—
pH
7
1980–2017
100%
—
~ typical
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 VT.
Compare your result with Windham County
Of the 1185 arsenic tests on record for Windham County (2017),
65% found none.
Of the 1095 chloride tests on record for Windham County (1980–2017),
0% found none, and half were below 2.5 mg/L.
Of the 1636 fluoride tests on record for Windham County (1980–2017),
0% found none, and half were below 150 µg/L.
Of the 767 iron tests on record for Windham County (1980–2017),
0% found none, and half were below 50 µg/L.
Of the 2550 lead tests on record for Windham County (2017),
0% found none, and half were below 2 µg/L.
Of the 926 manganese tests on record for Windham County (1980–2017),
0% found none, and half were below 3 µg/L.
Of the 1050 nitrate tests on record for Windham County (1994–2017),
0% found none, and half were below 250 µg/L.
Of the 1092 uranium tests on record for Windham County (2017),
55% found none.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Manganese 926 samples
Iron 767 samples
Lead 2550 samples
Chloride 1095 samples
Arsenic 1185 samples
Uranium 1092 samples
Nitrate 1050 samples
Fluoride 1636 samples
Nitrite 1034 samples
Sodium 763 samples
Hardness 537 samples
Limited data (<15 samples) — interpret with caution
Sulfate 7 samples
Total Coliform 1 sample
E. coli 1 sample
pH 7 samples
No private-well PFAS data for Windham County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Windham 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 Windham County
201Active public water systems
69,693Residents on public water
48%Households on private wells
Public water systems in Windham 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 Windham 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 Windham 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 Windham County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Windham 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 Windham County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Windham 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 VT with at least one sample for that analyte.