Data & Methodology — Morris County

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

Contaminant Data — All Analytes

1019 well testing events on record, covering 20 analytes. Data spans 1922 to 2024.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. NJ Avg
PFOA municipal 273 2022–2025 66%
160% of limit ~ typical
Manganese 630 1958–2022 80%
187% of limit ↓ 61% below
PFOS municipal 272 2022–2025 28%
132% of limit ↓ 22% below
Iron 625 1958–2022 81%
13% of limit ↓ 97% below
Radon 33 1987–2014 100%
16% of limit ↓ 62% below
Chloride 688 1958–2022 100%
17% of limit ↓ 42% below
Lead 509 1983–2022 17%
67% of limit ↑ 183% above
Uranium 34 1997–2014 62%
2% of limit ↓ 58% below
Arsenic 503 1983–2022 42%
20% of limit ~ typical
Sulfate 688 1958–2022 99%
9% of limit ↓ 45% below
Fluoride 562 1958–2022 74%
2% of limit ↓ 52% below
HFPO-DA (GenX) municipal 273 2022–2025 0%
— —
Nitrate 651 1958–2022 71%
9% of limit ↓ 63% below
Nitrite 629 1983–2022 17%
2% of limit ~ typical
PFHxS municipal 271 2022–2025 18%
48% of limit ~ typical
PFNA municipal 273 2022–2025 1%
21% of limit ↓ 52% below
Hardness 680 1958–2022 100%
— ~ typical
PFBS municipal 271 2022–2025 17%
— ↓ 21% below
pH 894 1958–2022 100%
— ~ typical
Sodium 680 1958–2022 100%
— ↓ 48% 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 Morris County

Of the 503 arsenic tests on record for Morris County (1983–2022), 58% found none.

Of the 688 chloride tests on record for Morris County (1958–2022), 0% found none, and half were below 42 mg/L.

Of the 562 fluoride tests on record for Morris County (1958–2022), 26% found none, and half were below 100 µg/L.

Of the 625 iron tests on record for Morris County (1958–2022), 19% found none, and half were below 18 µg/L.

Of the 509 lead tests on record for Morris County (1983–2022), 83% found none.

Of the 630 manganese tests on record for Morris County (1958–2022), 20% found none, and half were below 38 µg/L.

Of the 651 nitrate tests on record for Morris County (1958–2022), 29% found none, and half were below 400 µg/L.

Of the 688 sulfate tests on record for Morris County (1958–2022), 1% found none, and half were below 22 mg/L.

Of the 34 uranium tests on record for Morris County (1997–2014), 38% found none, and half were below 31.5 ng/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • PFOA 273 samples
  • Manganese 630 samples
  • PFOS 272 samples
  • Iron 625 samples
  • Radon 33 samples
  • Chloride 688 samples
  • Lead 509 samples
  • Uranium 34 samples
  • Arsenic 503 samples
  • Sulfate 688 samples
  • Fluoride 562 samples
  • HFPO-DA (GenX) 273 samples
  • Nitrate 651 samples
  • Nitrite 629 samples
  • PFHxS 271 samples
  • PFNA 273 samples
  • Hardness 680 samples
  • PFBS 271 samples
  • pH 894 samples
  • Sodium 680 samples

Public vs. Private Water in Morris County

302 Active public water systems
449,831 Residents on public water
25% Households on private wells

Public water systems in Morris 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 Morris 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 Morris County Prevalence NJ Average Source Year
Lead Heart disease rate 5.7% 5.8% 2020
Arsenic Cancer prevalence 7.2% 6.2% 2020
Arsenic Kidney disease rate 2.5% 2.7% 2020

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