Data & Methodology — Gloucester County

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

Contaminant Data — All Analytes

1866 well testing events on record, covering 22 analytes. Data spans 1949 to 2023.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. NJ Avg
Iron 924 1949–2023 90%
67% of limit ↓ 86% below
Manganese 922 1949–2023 94%
78% of limit ↓ 84% below
PFOA municipal 167 2020–2025 18%
171% of limit ~ typical
Radon 102 1988–2023 99%
13% of limit ↓ 68% below
PFOS municipal 167 2020–2025 9%
115% of limit ↓ 32% below
Lead 519 1970–2023 36%
5% of limit ↓ 79% below
Nitrate 813 1950–2023 77%
25% of limit ~ typical
PFNA municipal 166 2020–2025 9%
110% of limit ↑ 153% above
Arsenic 508 1974–2023 54%
10% of limit ↓ 40% below
Chloride 1682 1929–2023 100%
12% of limit ↓ 60% below
Sulfate 947 1949–2023 95%
5% of limit ↓ 69% below
PFHxS municipal 166 2020–2025 2%
42% of limit ~ typical
Fluoride 697 1950–2023 59%
5% of limit ~ typical
HFPO-DA (GenX) municipal 169 2020–2025 0%
— —
Nitrite 674 1973–2023 18%
1% of limit ↓ 23% below
Uranium 187 1988–2022 57%
0% of limit ↓ 95% below
Total Coliform 2 2003–2022 22%
— ~ typical
Sodium 1019 1950–2023 100%
— ↓ 46% below
pH 1353 1949–2023 100%
— ~ typical
PFBS municipal 165 2020–2025 7%
— ~ typical
Hardness 917 1949–2023 100%
— ↓ 74% below
E. coli 2 2003–2022 22%
— ~ 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 Gloucester County

Of the 508 arsenic tests on record for Gloucester County (1974–2023), 46% found none, and half were below 80 ng/L.

Of the 1682 chloride tests on record for Gloucester County (1929–2023), 0% found none, and half were below 29 mg/L.

Of the 697 fluoride tests on record for Gloucester County (1950–2023), 41% found none, and half were below 60 µg/L.

Of the 924 iron tests on record for Gloucester County (1949–2023), 10% found none, and half were below 140 µg/L.

Of the 519 lead tests on record for Gloucester County (1970–2023), 64% found none.

Of the 922 manganese tests on record for Gloucester County (1949–2023), 6% found none, and half were below 31.7 µg/L.

Of the 813 nitrate tests on record for Gloucester County (1950–2023), 23% found none, and half were below 1.06 mg/L.

Of the 947 sulfate tests on record for Gloucester County (1949–2023), 5% found none, and half were below 12 mg/L.

Of the 187 uranium tests on record for Gloucester County (1988–2022), 43% found none, and half were below 20 ng/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 924 samples
  • Manganese 922 samples
  • PFOA 167 samples
  • Radon 102 samples
  • PFOS 167 samples
  • Lead 519 samples
  • Nitrate 813 samples
  • PFNA 166 samples
  • Arsenic 508 samples
  • Chloride 1682 samples
  • Sulfate 947 samples
  • PFHxS 166 samples
  • Fluoride 697 samples
  • HFPO-DA (GenX) 169 samples
  • Nitrite 674 samples
  • Uranium 187 samples
  • Sodium 1019 samples
  • pH 1353 samples
  • PFBS 165 samples
  • Hardness 917 samples

Limited data (<15 samples) — interpret with caution

  • Total Coliform 2 samples
  • E. coli 2 samples

Public vs. Private Water in Gloucester County

181 Active public water systems
294,765 Residents on public water
18% Households on private wells

Public water systems in Gloucester 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 Gloucester 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 Gloucester County Prevalence NJ Average Source Year
Arsenic Cancer prevalence 7.0% 6.2% 2020
Arsenic Kidney disease rate 2.7% 2.7% 2020
Lead Heart disease rate 5.0% 5.8% 2020

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