Full contaminant data, sample history, and sourcing for Sherburne County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
542 well testing events on record, covering
19 analytes.
Data spans 1957 to 2025.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. MN Avg
Manganese
253
1957–2025
69%
200% of limit
↓ 59% below
Iron
351
1957–2025
68%
77% of limit
↓ 89% below
Nitrate
309
1963–2018
80%
24% of limit
~ typical
PFOS
municipal
39
2023–2025
10%
73% of limit
↓ 64% below
Arsenic
237
1974–2025
73%
14% of limit
↓ 84% below
PFOA
municipal
40
2022–2025
15%
39% of limit
↓ 91% below
Chloride
427
1957–2025
100%
7% of limit
~ typical
Lead
235
1974–2025
27%
1% of limit
↓ 99% below
Nitrite
284
1974–2018
36%
1% of limit
~ typical
Fluoride
316
1957–2025
77%
2% of limit
↓ 64% below
HFPO-DA (GenX)
municipal
40
2022–2025
0%
—
—
PFHxS
municipal
32
2023–2025
0%
—
—
PFNA
municipal
40
2022–2025
0%
—
—
Sulfate
413
1960–2025
98%
6% of limit
↓ 66% below
Uranium
176
2002–2018
79%
1% of limit
↓ 78% below
Hardness
188
1957–2018
100%
—
~ typical
PFBS
municipal
32
2023–2025
25%
—
↓ 37% below
pH
345
1957–2018
100%
—
~ typical
Sodium
346
1960–2025
99%
—
↓ 84% 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 Sherburne County
Of the 237 arsenic tests on record for Sherburne County (1974–2025),
27% found none, and half were below 0.68 µg/L.
Of the 427 chloride tests on record for Sherburne County (1957–2025),
0% found none, and half were below 16.3 mg/L.
Of the 316 fluoride tests on record for Sherburne County (1957–2025),
23% found none, and half were below 100 µg/L.
Of the 351 iron tests on record for Sherburne County (1957–2025),
32% found none, and half were below 41.3 µg/L.
Of the 235 lead tests on record for Sherburne County (1974–2025),
73% found none.
Of the 253 manganese tests on record for Sherburne County (1957–2025),
31% found none, and half were below 10.9 µg/L.
Of the 309 nitrate tests on record for Sherburne County (1963–2018),
20% found none, and half were below 820 µg/L.
Of the 413 sulfate tests on record for Sherburne County (1960–2025),
2% found none, and half were below 15.6 mg/L.
Of the 176 uranium tests on record for Sherburne County (2002–2018),
21% found none, and half were below 0.23 µg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Manganese 253 samples
Iron 351 samples
Nitrate 309 samples
PFOS 39 samples
Arsenic 237 samples
PFOA 40 samples
Chloride 427 samples
Lead 235 samples
Nitrite 284 samples
Fluoride 316 samples
HFPO-DA (GenX) 40 samples
PFNA 40 samples
Sulfate 413 samples
Uranium 176 samples
Hardness 188 samples
pH 345 samples
Sodium 346 samples
Public vs. Private Water in Sherburne County
79Active public water systems
58,253Residents on public water
42%Households on private wells
Public water systems in Sherburne 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 Sherburne 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.
This report aggregates data from the following public databases:
Water Quality Portal (WQP) — groundwater sample results for Sherburne County from EPA, USGS, and state agencies. Browse WQP data →
EPA Safe Drinking Water Information System (SDWIS) — public water system inventory used to estimate the share of residents on private wells. Browse SDWIS →
Census ACS 5-Year Estimates — well and cistern household counts (variable DP04_0074E) used to calculate the private-well percentage for Sherburne County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Sherburne County, which informs which contaminants are geologically likely. USGS Aquifer Atlas →
EPA UCMR 5 (2023–2025) — PFAS occurrence data from public water systems, used as a proxy indicator for aquifer PFAS exposure. Rows marked "municipal" in the table above come from this source. About UCMR 5 →
EPA Toxics Release Inventory (TRI) — industrial facility chemical releases near Sherburne County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Sherburne County, used in contamination risk scoring. Superfund site search →
CDC PLACES — county-level health outcome prevalence (kidney disease, cancer, heart disease) correlated with detected contaminants. About CDC PLACES →
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.