Data & Methodology — Ingham County

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

Contaminant Data — All Analytes

293 well testing events on record, covering 23 analytes. Data spans 1952 to 2018.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. MI Avg
Iron 215 1952–2016 100%
267% of limit ↓ 26% below
Manganese 124 1952–2017 100%
53% of limit ↓ 40% below
Arsenic 83 1975–2017 82%
20% of limit ↓ 33% below
Sulfate 248 1952–2016 100%
14% of limit ↓ 34% below
Chloride 249 1952–2016 100%
2% of limit ↓ 92% below
Fluoride 133 1952–2016 99%
5% of limit ↓ 39% below
HFPO-DA (GenX) municipal 54 2023–2025 0%
— —
Lead 39 1975–2017 15%
0% of limit ↓ 98% below
Nitrate 92 1952–2017 85%
0% of limit ↓ 100% below
Nitrite 24 1975–2017 46%
0% of limit ↓ 66% below
PFHxS municipal 54 2023–2025 0%
— —
PFNA municipal 55 2018–2025 0%
— —
PFOA municipal 55 2018–2025 0%
— —
PFOS municipal 54 2023–2025 0%
— —
Radon 2 1989 100%
1% of limit ↓ 86% below
Uranium 16 1954–2017 94%
2% of limit ↑ 103% above
Total Coliform 16 2016–2017 69%
— ~ typical
Sodium 216 1952–2016 100%
— ↓ 71% below
pH 253 1952–2017 100%
— ~ typical
PFBS municipal 54 2023–2025 0%
— —
Hardness 249 1952–2016 100%
— ~ typical
Fecal Coliform 16 2016–2017 38%
— ~ typical
E. coli 16 2016–2017 12%
— ~ 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 MI.

Compare your result with Ingham County

Of the 83 arsenic tests on record for Ingham County (1975–2017), 18% found none, and half were below 2 µg/L.

Of the 249 chloride tests on record for Ingham County (1952–2016), 0% found none, and half were below 4 mg/L.

Of the 133 fluoride tests on record for Ingham County (1952–2016), 1% found none, and half were below 200 µg/L.

Of the 215 iron tests on record for Ingham County (1952–2016), 0% found none, and half were below 800 µg/L.

Of the 39 lead tests on record for Ingham County (1975–2017), 85% found none.

Of the 124 manganese tests on record for Ingham County (1952–2017), 0% found none, and half were below 26.3 µg/L.

Of the 92 nitrate tests on record for Ingham County (1952–2017), 15% found none.

Of the 248 sulfate tests on record for Ingham County (1952–2016), 0% found none, and half were below 34.5 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Iron 215 samples
  • Manganese 124 samples
  • Arsenic 83 samples
  • Sulfate 248 samples
  • Chloride 249 samples
  • Fluoride 133 samples
  • Lead 39 samples
  • Nitrate 92 samples
  • Nitrite 24 samples
  • PFNA 55 samples
  • PFOA 55 samples
  • Uranium 16 samples
  • Total Coliform 16 samples
  • Sodium 216 samples
  • pH 253 samples
  • Hardness 249 samples
  • Fecal Coliform 16 samples
  • E. coli 16 samples

Limited data (<15 samples) — interpret with caution

  • Radon 2 samples

Public vs. Private Water in Ingham County

109 Active public water systems
279,046 Residents on public water
2% Households on private wells

Public water systems in Ingham 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 Ingham 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 Ingham County Prevalence MI Average Source Year
Arsenic Cancer prevalence 7.1% 7.2% 2023
Arsenic Cancer prevalence 5.8% 7.2% 2020
Arsenic Kidney disease rate 2.7% 3.2% 2020

Source: CDC PLACES county-level estimates. Raw data: Download Ingham 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 MI with at least one sample for that analyte.

Last updated: 2026-08-04

Full methodology →