Data & Methodology — Sussex County

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

Contaminant Data — All Analytes

232 well testing events on record, covering 22 analytes. Data spans 1923 to 2025.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. NJ Avg
PFOA municipal 72 2022–2025 35%
170% of limit ~ typical
PFOS municipal 73 2022–2025 30%
130% of limit ↓ 23% below
Uranium 31 1999–2022 94%
8% of limit ↑ 65% above
Radon 59 1998–2011 100%
13% of limit ↓ 69% below
Manganese 178 1957–2022 66%
14% of limit ↓ 97% below
Chloride 179 1957–2022 100%
16% of limit ↓ 44% below
Iron 176 1957–2022 54%
6% of limit ↓ 99% below
Nitrate 148 1957–2022 83%
15% of limit ↓ 38% below
Arsenic 116 1988–2022 52%
3% of limit ↓ 84% below
Fluoride 156 1957–2022 56%
3% of limit ↓ 43% below
HFPO-DA (GenX) municipal 74 2022–2025 0%
— —
Lead 99 1988–2022 36%
1% of limit ↓ 97% below
Nitrite 138 1973–2022 17%
0% of limit ↓ 70% below
PFHxS municipal 73 2022–2025 7%
33% of limit ↓ 25% below
PFNA municipal 74 2022–2025 1%
19% of limit ↓ 56% below
Sulfate 179 1957–2022 99%
8% of limit ↓ 52% below
pH 191 1957–2023 100%
— ~ typical
Sodium 166 1957–2022 100%
— ↓ 59% below
Total Coliform 1 2000–2022 5%
— ~ typical
E. coli 1 2000–2022 0%
— —
Hardness 165 1957–2022 100%
— ↑ 63% above
PFBS municipal 74 2022–2025 34%
— ↑ 32% above

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 Sussex County

Of the 116 arsenic tests on record for Sussex County (1988–2022), 48% found none, and half were below 80 ng/L.

Of the 179 chloride tests on record for Sussex County (1957–2022), 0% found none, and half were below 41 mg/L.

Of the 156 fluoride tests on record for Sussex County (1957–2022), 44% found none, and half were below 40 µg/L.

Of the 176 iron tests on record for Sussex County (1957–2022), 46% found none, and half were below 4.65 µg/L.

Of the 99 lead tests on record for Sussex County (1988–2022), 64% found none.

Of the 178 manganese tests on record for Sussex County (1957–2022), 34% found none, and half were below 1.4 µg/L.

Of the 148 nitrate tests on record for Sussex County (1957–2022), 17% found none, and half were below 785 µg/L.

Of the 179 sulfate tests on record for Sussex County (1957–2022), 1% found none, and half were below 20 mg/L.

Of the 31 uranium tests on record for Sussex County (1999–2022), 6% found none, and half were below 1.07 µg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • PFOA 72 samples
  • PFOS 73 samples
  • Uranium 31 samples
  • Radon 59 samples
  • Manganese 178 samples
  • Chloride 179 samples
  • Iron 176 samples
  • Nitrate 148 samples
  • Arsenic 116 samples
  • Fluoride 156 samples
  • HFPO-DA (GenX) 74 samples
  • Lead 99 samples
  • Nitrite 138 samples
  • PFHxS 73 samples
  • PFNA 74 samples
  • Sulfate 179 samples
  • pH 191 samples
  • Sodium 166 samples
  • Hardness 165 samples
  • PFBS 74 samples

Limited data (<15 samples) — interpret with caution

  • Total Coliform 1 sample
  • E. coli 1 sample

Public vs. Private Water in Sussex County

478 Active public water systems
202,703 Residents on public water
50% Households on private wells

Public water systems in Sussex 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 Sussex 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 Sussex County Prevalence NJ Average Source Year
Arsenic Cancer prevalence 6.0% 6.2% 2020
Arsenic Kidney disease rate 2.2% 2.7% 2020

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