Full contaminant data, sample history, and sourcing for Franklin County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
9 well testing events on record, covering
20 analytes.
Data spans 1953 to 2025.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. VT Avg
Manganese
1078
1966–2023
100%
18% of limit
↓ 97% below
Iron
893
1966–2023
100%
17% of limit
↓ 92% below
Radon
21
2014
100%
45% of limit
↓ 90% below
Arsenic
2019
2014–2023
74%
10% of limit
↓ 81% below
Lead
3141
2014–2023
89%
13% of limit
↓ 81% below
Chloride
1870
1966–2023
100%
2% of limit
↓ 79% below
Uranium
1945
2014–2023
100%
7% of limit
~ typical
Nitrate
3063
1966–2023
100%
2% of limit
↓ 24% below
Fluoride
2579
1966–2023
100%
4% of limit
~ typical
HFPO-DA (GenX)
municipal
8
2025
0%
—
—
Nitrite
3017
2014–2023
100%
1% of limit
↓ 50% below
PFHxS
municipal
8
2025
0%
—
—
PFNA
municipal
8
2025
0%
—
—
PFOA
municipal
8
2025
0%
—
—
PFOS
municipal
8
2025
0%
—
—
Sulfate
3
1966–2023
100%
8% of limit
↑ 47% above
Hardness
702
1966–2023
100%
—
↑ 45% above
Sodium
868
1966–2023
100%
—
~ typical
pH
950
1966–2023
100%
—
~ typical
PFBS
municipal
8
2025
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 VT.
Compare your result with Franklin County
Of the 2019 arsenic tests on record for Franklin County (2014–2023),
26% found none, and half were below 1 µg/L.
Of the 1870 chloride tests on record for Franklin County (1966–2023),
0% found none, and half were below 4.55 mg/L.
Of the 2579 fluoride tests on record for Franklin County (1966–2023),
0% found none, and half were below 150 µg/L.
Of the 893 iron tests on record for Franklin County (1966–2023),
0% found none, and half were below 50 µg/L.
Of the 3141 lead tests on record for Franklin County (2014–2023),
11% found none, and half were below 2 µg/L.
Of the 1078 manganese tests on record for Franklin County (1966–2023),
0% found none, and half were below 9 µg/L.
Of the 3063 nitrate tests on record for Franklin County (1966–2023),
0% found none, and half were below 250 µg/L.
Of the 1945 uranium tests on record for Franklin County (2014–2023),
0% found none, and half were below 2 µg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Manganese 1078 samples
Iron 893 samples
Radon 21 samples
Arsenic 2019 samples
Lead 3141 samples
Chloride 1870 samples
Uranium 1945 samples
Nitrate 3063 samples
Fluoride 2579 samples
Nitrite 3017 samples
Hardness 702 samples
Sodium 868 samples
pH 950 samples
Limited data (<15 samples) — interpret with caution
Sulfate 3 samples
No private-well PFAS data for Franklin County
We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Franklin 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 Franklin County
82Active public water systems
36,172Residents on public water
56%Households on private wells
Public water systems in Franklin 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 Franklin 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 Franklin 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 Franklin County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Franklin 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 Franklin County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Franklin 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.