Data & Methodology — Stevens County

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

Contaminant Data — All Analytes

73 well testing events on record, covering 19 analytes. Data spans 1964 to 2023.

Contaminant Samples Years Detection Rate Distribution LowModHigh vs. Limit vs. MN Avg
Manganese 46 1964–2007 100%
472% of limit ~ typical
Arsenic 17 1994–2006 100%
290% of limit ↑ 238% above
PFOS municipal 10 2025 80%
191% of limit ~ typical
Iron 47 1964–2007 98%
617% of limit ~ typical
PFOA municipal 21 2007–2025 86%
126% of limit ↓ 71% below
Sulfate 51 1964–2014 100%
75% of limit ↑ 296% above
PFHxS municipal 9 2025 78%
48% of limit ↓ 40% below
Lead 33 1994–2006 45%
1% of limit ↓ 97% below
Nitrate 47 1964–2007 77%
1% of limit ↓ 96% below
Chloride 60 1964–2025 100%
5% of limit ↓ 40% below
Fluoride 26 1964–2007 85%
5% of limit ↓ 33% below
HFPO-DA (GenX) municipal 2 2025 0%
— —
Nitrite 19 1991–2007 63%
0% of limit ↓ 95% below
PFNA municipal 5 2007–2025 40%
10% of limit ↓ 42% below
Uranium 11 2006 100%
7% of limit ↑ 74% above
Hardness 16 1964–1982 100%
— ↑ 67% above
PFBS municipal 8 2025 75%
— ↓ 41% below
pH 21 1964–1993 100%
— ~ typical
Sodium 46 1964–2007 100%
— ↓ 28% 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 Stevens County

Of the 60 chloride tests on record for Stevens County (1964–2025), 0% found none, and half were below 11.5 mg/L.

Of the 26 fluoride tests on record for Stevens County (1964–2007), 15% found none, and half were below 175 µg/L.

Of the 47 iron tests on record for Stevens County (1964–2007), 2% found none, and half were below 1.8 mg/L.

Of the 33 lead tests on record for Stevens County (1994–2006), 55% found none.

Of the 46 manganese tests on record for Stevens County (1964–2007), 0% found none, and half were below 236 µg/L.

Of the 47 nitrate tests on record for Stevens County (1964–2007), 23% found none, and half were below 9 µg/L.

Of the 51 sulfate tests on record for Stevens County (1964–2014), 0% found none, and half were below 187 mg/L.

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Data Coverage & Gaps

Well-sampled analytes (15+ samples)

  • Manganese 46 samples
  • Arsenic 17 samples
  • Iron 47 samples
  • PFOA 21 samples
  • Sulfate 51 samples
  • Lead 33 samples
  • Nitrate 47 samples
  • Chloride 60 samples
  • Fluoride 26 samples
  • Nitrite 19 samples
  • Hardness 16 samples
  • pH 21 samples
  • Sodium 46 samples

Limited data (<15 samples) — interpret with caution

  • PFOS 10 samples
  • PFHxS 9 samples
  • PFNA 5 samples
  • Uranium 11 samples
  • PFBS 8 samples

Public vs. Private Water in Stevens County

21 Active public water systems
8,136 Residents on public water
32% Households on private wells

Public water systems in Stevens 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 Stevens 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 Stevens County Prevalence MN Average Source Year
Arsenic Cancer prevalence 6.1% 7.0% 2020
Arsenic Kidney disease rate 2.6% 2.9% 2020
Lead Heart disease rate 6.3% 6.6% 2020

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