Data & Methodology — Cumberland County

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

Contaminant Data — All Analytes

601 well testing events on record, covering 22 analytes. Data spans 1953 to 2024.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. NJ Avg
Iron 312 1953–2023 82%
39% of limit ↓ 92% below
PFOA municipal 53 2020–2025 32%
160% of limit ~ typical
Manganese 324 1963–2023 98%
46% of limit ↓ 90% below
Nitrate 315 1953–2023 84%
47% of limit ↑ 93% above
PFOS municipal 52 2020–2025 13%
168% of limit ~ typical
Radon 117 1988–2023 97%
12% of limit ↓ 70% below
Chloride 514 1953–2023 100%
6% of limit ↓ 80% below
Lead 204 1974–2023 50%
7% of limit ↓ 72% below
Sulfate 318 1953–2023 97%
4% of limit ↓ 75% below
Arsenic 248 1974–2023 37%
3% of limit ↓ 80% below
Fluoride 274 1953–2023 51%
2% of limit ↓ 52% below
HFPO-DA (GenX) municipal 53 2020–2025 0%
— —
Nitrite 292 1974–2023 18%
1% of limit ↓ 41% below
PFHxS municipal 53 2020–2025 4%
34% of limit ↓ 22% below
PFNA municipal 52 2020–2025 2%
39% of limit ~ typical
Uranium 117 1988–2022 49%
0% of limit ↓ 97% below
PFBS municipal 53 2020–2025 2%
— ↓ 35% below
Hardness 309 1953–2023 100%
— ↓ 74% below
E. coli 4 2003–2022 44%
— ~ typical
Total Coliform 4 2003–2022 44%
— ~ typical
Sodium 343 1963–2023 100%
— ↓ 86% below
pH 453 1953–2023 100%
— ↓ 29% 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 NJ.

Compare your result with Cumberland County

Of the 248 arsenic tests on record for Cumberland County (1974–2023), 63% found none.

Of the 514 chloride tests on record for Cumberland County (1953–2023), 0% found none, and half were below 14.9 mg/L.

Of the 274 fluoride tests on record for Cumberland County (1953–2023), 49% found none, and half were below 5 µg/L.

Of the 312 iron tests on record for Cumberland County (1953–2023), 18% found none, and half were below 47.8 µg/L.

Of the 204 lead tests on record for Cumberland County (1974–2023), 50% found none.

Of the 324 manganese tests on record for Cumberland County (1963–2023), 2% found none, and half were below 22.5 µg/L.

Of the 315 nitrate tests on record for Cumberland County (1953–2023), 16% found none, and half were below 3.4 mg/L.

Of the 318 sulfate tests on record for Cumberland County (1953–2023), 3% found none, and half were below 9.8 mg/L.

Of the 117 uranium tests on record for Cumberland County (1988–2022), 51% found none.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 312 samples
  • PFOA 53 samples
  • Manganese 324 samples
  • Nitrate 315 samples
  • PFOS 52 samples
  • Radon 117 samples
  • Chloride 514 samples
  • Lead 204 samples
  • Sulfate 318 samples
  • Arsenic 248 samples
  • Fluoride 274 samples
  • HFPO-DA (GenX) 53 samples
  • Nitrite 292 samples
  • PFHxS 53 samples
  • PFNA 52 samples
  • Uranium 117 samples
  • PFBS 53 samples
  • Hardness 309 samples
  • Sodium 343 samples
  • pH 453 samples

Limited data (<15 samples) — interpret with caution

  • E. coli 4 samples
  • Total Coliform 4 samples

Public vs. Private Water in Cumberland County

126 Active public water systems
115,688 Residents on public water
38% Households on private wells

Public water systems in Cumberland 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 Cumberland 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 Cumberland County Prevalence NJ Average Source Year
Arsenic Cancer prevalence 5.5% 6.2% 2020
Arsenic Kidney disease rate 3.1% 2.7% 2020
Lead Heart disease rate 6.6% 5.8% 2020

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