Full contaminant data, sample history, and sourcing for Lamoille County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
4 well testing events on record, covering
20 analytes.
Data spans 1952 to 2025.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. VT Avg
Radon
421
—
100%
284% of limit
↓ 37% below
Manganese
639
1966
100%
18% of limit
↓ 97% below
Iron
521
1966
100%
17% of limit
↓ 92% below
Arsenic
1625
—
83%
30% of limit
↓ 42% below
Lead
1677
—
70%
13% of limit
↓ 81% below
Chloride
1371
1966
100%
2% of limit
↓ 81% below
Uranium
1218
—
93%
3% of limit
↓ 59% below
Nitrate
1925
1966
100%
2% of limit
↓ 24% below
Fluoride
1710
1966
100%
2% of limit
~ typical
HFPO-DA (GenX)
municipal
2
2023
0%
—
—
Nitrite
1881
—
100%
2% of limit
~ typical
PFHxS
municipal
2
2023
0%
—
—
PFNA
municipal
2
2023
0%
—
—
PFOA
municipal
2
2023
0%
—
—
PFOS
municipal
2
2023
0%
—
—
Sulfate
1
1966
100%
4% of limit
↓ 22% below
Sodium
514
1966
100%
—
↓ 52% below
pH
485
1966
100%
—
~ typical
PFBS
municipal
2
2023
0%
—
—
Hardness
414
1966
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 Lamoille County
Of the 1625 arsenic tests on record for Lamoille County,
17% found none, and half were below 3 µg/L.
Of the 1371 chloride tests on record for Lamoille County (1966),
0% found none, and half were below 4.15 mg/L.
Of the 1710 fluoride tests on record for Lamoille County (1966),
0% found none, and half were below 100 µg/L.
Of the 521 iron tests on record for Lamoille County (1966),
0% found none, and half were below 50 µg/L.
Of the 1677 lead tests on record for Lamoille County,
30% found none, and half were below 1 µg/L.
Of the 639 manganese tests on record for Lamoille County (1966),
0% found none, and half were below 9 µg/L.
Of the 1925 nitrate tests on record for Lamoille County (1966),
0% found none, and half were below 250 µg/L.
Of the 1218 uranium tests on record for Lamoille County,
7% found none, and half were below 1 µg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Radon 421 samples
Manganese 639 samples
Iron 521 samples
Arsenic 1625 samples
Lead 1677 samples
Chloride 1371 samples
Uranium 1218 samples
Nitrate 1925 samples
Fluoride 1710 samples
Nitrite 1881 samples
Sodium 514 samples
pH 485 samples
Hardness 414 samples
Limited data (<15 samples) — interpret with caution
Sulfate 1 sample
No private-well PFAS data for Lamoille County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Lamoille 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 Lamoille County
69Active public water systems
24,007Residents on public water
48%Households on private wells
Public water systems in Lamoille 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 Lamoille 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 Lamoille 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 Lamoille County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Lamoille 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 Lamoille County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Lamoille 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.