Data & Methodology — Caledonia County

Full contaminant data, sample history, and sourcing for Caledonia County. For readers who want to go beyond the summary.

Contaminant Data — All Analytes

33 well testing events on record, covering 22 analytes. Data spans 1952 to 2025.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. VT Avg
Radon 240 1992–2002 100%
252% of limit ↓ 44% below
Iron 494 1966–2017 99%
17% of limit ↓ 92% below
Manganese 597 1966–2017 100%
6% of limit ↓ 99% below
Lead 3532 2002–2017 95%
13% of limit ↓ 81% below
Arsenic 1067 2002–2017 13%
40% of limit ↓ 22% below
Uranium 868 2002–2017 83%
3% of limit ↓ 59% below
Nitrate 981 1966–2017 99%
2% of limit ↓ 24% below
Chloride 994 1966–2017 100%
1% of limit ↓ 88% below
Fluoride 991 1966–2017 98%
4% of limit ~ typical
HFPO-DA (GenX) municipal 5 2025 0%
— —
Nitrite 951 1992–2017 98%
2% of limit ~ typical
PFHxS municipal 5 2025 0%
— —
PFNA municipal 5 2025 0%
— —
PFOA municipal 5 2025 0%
— —
PFOS municipal 5 2025 0%
— —
Sulfate 21 1966–2017 100%
9% of limit ↑ 64% above
Total Coliform 1 2002–2017 50%
— ~ typical
Sodium 490 1966–2017 100%
— ↓ 60% below
pH 54 1966–2017 100%
— ~ typical
PFBS municipal 5 2025 0%
— —
Hardness 295 1966–2017 100%
— ↓ 41% below
E. coli 1 2002–2017 100%
— ↓ 79% below

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 Caledonia County

Of the 1067 arsenic tests on record for Caledonia County (2002–2017), 87% found none.

Of the 994 chloride tests on record for Caledonia County (1966–2017), 0% found none, and half were below 2.5 mg/L.

Of the 991 fluoride tests on record for Caledonia County (1966–2017), 2% found none, and half were below 150 µg/L.

Of the 494 iron tests on record for Caledonia County (1966–2017), 1% found none, and half were below 50 µg/L.

Of the 3532 lead tests on record for Caledonia County (2002–2017), 5% found none, and half were below 2 µg/L.

Of the 597 manganese tests on record for Caledonia County (1966–2017), 0% found none, and half were below 3 µg/L.

Of the 981 nitrate tests on record for Caledonia County (1966–2017), 1% found none, and half were below 250 µg/L.

Of the 21 sulfate tests on record for Caledonia County (1966–2017), 0% found none, and half were below 23.2 mg/L.

Of the 868 uranium tests on record for Caledonia County (2002–2017), 17% found none, and half were below 1 µg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Radon 240 samples
  • Iron 494 samples
  • Manganese 597 samples
  • Lead 3532 samples
  • Arsenic 1067 samples
  • Uranium 868 samples
  • Nitrate 981 samples
  • Chloride 994 samples
  • Fluoride 991 samples
  • Nitrite 951 samples
  • Sulfate 21 samples
  • Sodium 490 samples
  • pH 54 samples
  • Hardness 295 samples

Limited data (<15 samples) — interpret with caution

  • Total Coliform 1 sample
  • E. coli 1 sample

No private-well PFAS data for Caledonia County

We have no private well sampling data for PFAS compounds (PFOA, PFOS, PFNA, and related chemicals) in Caledonia 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 Caledonia County

64 Active public water systems
23,630 Residents on public water
50% Households on private wells

Public water systems in Caledonia 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 Caledonia 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.

Contaminant Associated Condition Caledonia County Prevalence VT Average Source Year
Arsenic Cancer prevalence 6.0% 7.0% 2020
Arsenic Kidney disease rate 2.5% 2.8% 2020
Lead Heart disease rate 5.5% 6.3% 2020

Source: CDC PLACES county-level estimates. Raw data: Download Caledonia County CDC PLACES data →

Data Sources

This report aggregates data from the following public databases:

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.

Last updated: 2026-07-31

Full methodology →