Data & Methodology — Ocean County

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

Contaminant Data — All Analytes

2848 well testing events on record, covering 22 analytes. Data spans 1945 to 2026.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. NJ Avg
Iron 668 1947–2023 85%
93% of limit ↓ 80% below
PFOA municipal 210 2020–2025 20%
135% of limit ↓ 32% below
Manganese 654 1948–2023 87%
56% of limit ↓ 88% below
PFOS municipal 209 2020–2025 4%
122% of limit ↓ 28% below
Radon 78 1990–2018 100%
7% of limit ↓ 83% below
Chloride 2682 1945–2023 100%
2% of limit ↓ 95% below
PFHxS municipal 207 2020–2025 2%
112% of limit ↑ 155% above
Nitrate 707 1945–2023 79%
1% of limit ↓ 94% below
Fluoride 409 1945–2023 64%
3% of limit ↓ 43% below
Lead 484 1972–2023 19%
7% of limit ↓ 72% below
Arsenic 262 1975–2023 37%
10% of limit ↓ 40% below
Sulfate 739 1945–2023 96%
3% of limit ↓ 82% below
PFNA municipal 208 2020–2025 0%
— —
HFPO-DA (GenX) municipal 210 2020–2025 0%
— —
Nitrite 560 1973–2023 19%
1% of limit ↓ 41% below
Uranium 77 1990–2022 19%
0% of limit ↓ 98% below
E. coli 7 2003–2022 43%
— ~ typical
Hardness 730 1945–2023 100%
— ↓ 92% below
PFBS municipal 208 2020–2025 11%
— ~ typical
pH 1293 1945–2023 100%
— ~ typical
Sodium 826 1957–2023 100%
— ↓ 90% below
Total Coliform 7 2003–2022 50%
— ~ 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 Ocean County

Of the 262 arsenic tests on record for Ocean County (1975–2023), 63% found none.

Of the 2682 chloride tests on record for Ocean County (1945–2023), 0% found none, and half were below 3.8 mg/L.

Of the 409 fluoride tests on record for Ocean County (1945–2023), 36% found none, and half were below 80 µg/L.

Of the 668 iron tests on record for Ocean County (1947–2023), 15% found none, and half were below 182 µg/L.

Of the 484 lead tests on record for Ocean County (1972–2023), 81% found none.

Of the 654 manganese tests on record for Ocean County (1948–2023), 13% found none, and half were below 20 µg/L.

Of the 707 nitrate tests on record for Ocean County (1945–2023), 21% found none, and half were below 60 µg/L.

Of the 739 sulfate tests on record for Ocean County (1945–2023), 4% found none, and half were below 7.2 mg/L.

Of the 77 uranium tests on record for Ocean County (1990–2022), 81% found none.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 668 samples
  • PFOA 210 samples
  • Manganese 654 samples
  • PFOS 209 samples
  • Radon 78 samples
  • Chloride 2682 samples
  • PFHxS 207 samples
  • Nitrate 707 samples
  • Fluoride 409 samples
  • Lead 484 samples
  • Arsenic 262 samples
  • Sulfate 739 samples
  • PFNA 208 samples
  • HFPO-DA (GenX) 210 samples
  • Nitrite 560 samples
  • Uranium 77 samples
  • Hardness 730 samples
  • PFBS 208 samples
  • pH 1293 samples
  • Sodium 826 samples

Limited data (<15 samples) — interpret with caution

  • E. coli 7 samples
  • Total Coliform 7 samples

Public vs. Private Water in Ocean County

212 Active public water systems
721,434 Residents on public water
17% Households on private wells

Public water systems in Ocean 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 Ocean 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 Ocean County Prevalence NJ Average Source Year
Arsenic Cancer prevalence 8.4% 6.2% 2020
Arsenic Kidney disease rate 2.4% 2.7% 2020
Lead Heart disease rate 5.4% 5.8% 2020

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