Data & Methodology — Crow Wing County

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

Contaminant Data — All Analytes

728 well testing events on record, covering 20 analytes. Data spans 1965 to 2024.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. MN Avg
Manganese 569 1965–2025 59%
270% of limit ↓ 45% below
Iron 583 1965–2025 56%
171% of limit ↓ 76% below
PFOA municipal 96 2005–2025 44%
34% of limit ↓ 92% below
PFOS municipal 75 2023–2025 39%
31% of limit ↓ 85% below
Nitrate 204 1965–2013 62%
0% of limit ↓ 99% below
Arsenic 497 1980–2025 24%
16% of limit ↓ 81% below
Chloride 598 1965–2025 96%
3% of limit ↓ 56% below
Lead 531 1980–2025 14%
1% of limit ↓ 97% below
Fluoride 286 1965–2025 40%
4% of limit ↓ 46% below
HFPO-DA (GenX) municipal 66 2022–2025 0%
— —
Nitrite 116 1992–2013 11%
0% of limit ↓ 80% below
PFHxS municipal 9 2023 56%
32% of limit ↓ 60% below
PFNA municipal 71 2019–2025 15%
6% of limit ↓ 66% below
Radon 1 2013 100%
100% of limit ↑ 93% above
Sulfate 583 1965–2025 88%
2% of limit ↓ 90% below
Uranium 91 1980–2013 80%
0% of limit ↓ 98% below
Sodium 575 1965–2025 98%
— ↓ 76% below
pH 67 1965–2014 100%
— ~ typical
PFBS municipal 10 2023 60%
— ↑ 131% above
Hardness 37 1965–2013 100%
— ↓ 58% 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 MN.

Compare your result with Crow Wing County

Of the 497 arsenic tests on record for Crow Wing County (1980–2025), 76% found none.

Of the 598 chloride tests on record for Crow Wing County (1965–2025), 4% found none, and half were below 7.32 mg/L.

Of the 286 fluoride tests on record for Crow Wing County (1965–2025), 60% found none.

Of the 583 iron tests on record for Crow Wing County (1965–2025), 44% found none, and half were below 35.1 µg/L.

Of the 531 lead tests on record for Crow Wing County (1980–2025), 85% found none.

Of the 569 manganese tests on record for Crow Wing County (1965–2025), 41% found none, and half were below 28.8 µg/L.

Of the 204 nitrate tests on record for Crow Wing County (1965–2013), 38% found none, and half were below 2 µg/L.

Of the 92 pfoa tests on record for Crow Wing County (2005–2025), 54% found none.

Of the 71 pfos tests on record for Crow Wing County (2024–2025), 59% found none.

Of the 583 sulfate tests on record for Crow Wing County (1965–2025), 12% found none, and half were below 4.39 mg/L.

Of the 91 uranium tests on record for Crow Wing County (1980–2013), 20% found none, and half were below 10 ng/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Manganese 569 samples
  • Iron 583 samples
  • PFOA 96 samples
  • PFOS 75 samples
  • Nitrate 204 samples
  • Arsenic 497 samples
  • Chloride 598 samples
  • Lead 531 samples
  • Fluoride 286 samples
  • HFPO-DA (GenX) 66 samples
  • Nitrite 116 samples
  • PFNA 71 samples
  • Sulfate 583 samples
  • Uranium 91 samples
  • Sodium 575 samples
  • pH 67 samples
  • Hardness 37 samples

Limited data (<15 samples) — interpret with caution

  • PFHxS 9 samples
  • Radon 1 sample
  • PFBS 10 samples

Public vs. Private Water in Crow Wing County

385 Active public water systems
79,303 Residents on public water
58% Households on private wells

Public water systems in Crow Wing 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 Crow Wing 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 Crow Wing County Prevalence MN Average Source Year
Arsenic Cancer prevalence 6.1% 7.0% 2020
Arsenic Kidney disease rate 2.5% 2.9% 2020
Lead Heart disease rate 7.8% 6.6% 2020

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

Last updated: 2026-08-04

Full methodology →