Data & Methodology — Bergen County

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

Contaminant Data — All Analytes

325 well testing events on record, covering 20 analytes. Data spans 1923 to 2024.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. NJ Avg
PFOA municipal 192 2022–2025 73%
275% of limit ↑ 39% above
PFOS municipal 191 2022–2025 50%
185% of limit ~ typical
Radon 32 1986–1991 100%
33% of limit ~ typical
Chloride 209 1959–2022 100%
14% of limit ↓ 53% below
Manganese 187 1959–2022 46%
6% of limit ↓ 99% below
Lead 159 1983–2022 19%
67% of limit ↑ 183% above
Iron 187 1959–2022 61%
4% of limit ↓ 99% below
Uranium 44 1986–1991 98%
9% of limit ↑ 89% above
Arsenic 72 1987–2022 62%
20% of limit ~ typical
Sulfate 209 1959–2022 100%
10% of limit ↓ 38% below
PFNA municipal 189 2022–2025 4%
64% of limit ↑ 47% above
PFHxS municipal 191 2022–2025 26%
39% of limit ~ typical
Nitrate 209 1959–2022 87%
23% of limit ~ typical
Nitrite 188 1982–2022 14%
2% of limit ~ typical
HFPO-DA (GenX) municipal 192 2022–2025 0%
— —
Fluoride 188 1959–2022 63%
2% of limit ↓ 52% below
Hardness 202 1959–2022 100%
— ~ typical
Sodium 195 1959–2022 100%
— ↓ 66% below
pH 230 1959–2022 100%
— ~ typical
PFBS municipal 191 2022–2025 42%
— ~ 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 NJ.

Compare your result with Bergen County

Of the 72 arsenic tests on record for Bergen County (1987–2022), 38% found none, and half were below 0.33 µg/L.

Of the 209 chloride tests on record for Bergen County (1959–2022), 0% found none, and half were below 34 mg/L.

Of the 188 fluoride tests on record for Bergen County (1959–2022), 37% found none, and half were below 100 µg/L.

Of the 187 iron tests on record for Bergen County (1959–2022), 39% found none, and half were below 5 µg/L.

Of the 159 lead tests on record for Bergen County (1983–2022), 81% found none.

Of the 187 manganese tests on record for Bergen County (1959–2022), 54% found none.

Of the 209 nitrate tests on record for Bergen County (1959–2022), 13% found none, and half were below 2 mg/L.

Of the 209 sulfate tests on record for Bergen County (1959–2022), 0% found none, and half were below 26 mg/L.

Of the 44 uranium tests on record for Bergen County (1986–1991), 2% found none, and half were below 2.3 µg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • PFOA 192 samples
  • PFOS 191 samples
  • Radon 32 samples
  • Chloride 209 samples
  • Manganese 187 samples
  • Lead 159 samples
  • Iron 187 samples
  • Uranium 44 samples
  • Arsenic 72 samples
  • Sulfate 209 samples
  • PFNA 189 samples
  • PFHxS 191 samples
  • Nitrate 209 samples
  • Nitrite 188 samples
  • HFPO-DA (GenX) 192 samples
  • Fluoride 188 samples
  • Hardness 202 samples
  • Sodium 195 samples
  • pH 230 samples
  • PFBS 191 samples

Public vs. Private Water in Bergen County

49 Active public water systems
340,855 Residents on public water
3% Households on private wells

Public water systems in Bergen 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 Bergen 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 Bergen County Prevalence NJ Average Source Year
Arsenic Cancer prevalence 5.3% 6.2% 2020
Arsenic Kidney disease rate 2.2% 2.7% 2020
Lead Heart disease rate 5.5% 5.8% 2020

Source: CDC PLACES county-level estimates. Raw data: Download Bergen 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 NJ with at least one sample for that analyte.

Last updated: 2026-08-04

Full methodology →