Full contaminant data, sample history, and sourcing for Morrison County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
395 well testing events on record, covering
20 analytes.
Data spans 1963 to 2024.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. MN Avg
Manganese
230
1966–2025
70%
286% of limit
↓ 42% below
Iron
348
1966–2025
70%
28% of limit
↓ 96% below
Nitrate
53
1966–2013
74%
9% of limit
↓ 63% below
Arsenic
156
1994–2025
73%
17% of limit
↓ 80% below
Lead
157
1993–2025
14%
2% of limit
↓ 94% below
Chloride
379
1966–2025
97%
3% of limit
↓ 55% below
Fluoride
220
1966–2025
87%
5% of limit
↓ 28% below
HFPO-DA (GenX)
municipal
11
2021–2025
0%
—
—
Nitrite
10
1974–2013
50%
1% of limit
↓ 42% below
PFHxS
municipal
2
2024
0%
—
—
PFNA
municipal
11
2021–2025
0%
—
—
PFOA
municipal
11
2021–2025
18%
10% of limit
↓ 98% below
PFOS
municipal
9
2024–2025
22%
16% of limit
↓ 92% below
Radon
1
2013
100%
57% of limit
~ typical
Sulfate
251
1966–2025
96%
4% of limit
↓ 77% below
Uranium
1
2013
100%
2% of limit
↓ 55% below
Sodium
242
1966–2025
100%
—
↓ 76% below
pH
179
1966–2014
100%
—
~ typical
PFBS
municipal
2
2024
0%
—
—
Hardness
70
1966–2013
100%
—
↓ 50% 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 Morrison County
Of the 156 arsenic tests on record for Morrison County (1994–2025),
27% found none, and half were below 0.672 µg/L.
Of the 379 chloride tests on record for Morrison County (1966–2025),
3% found none, and half were below 8.3 mg/L.
Of the 220 fluoride tests on record for Morrison County (1966–2025),
13% found none, and half were below 180 µg/L.
Of the 348 iron tests on record for Morrison County (1966–2025),
30% found none, and half were below 20 µg/L.
Of the 157 lead tests on record for Morrison County (1993–2025),
86% found none.
Of the 230 manganese tests on record for Morrison County (1966–2025),
30% found none, and half were below 80.8 µg/L.
Of the 53 nitrate tests on record for Morrison County (1966–2013),
26% found none, and half were below 430 µg/L.
Of the 251 sulfate tests on record for Morrison County (1966–2025),
4% found none, and half were below 10.5 mg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Manganese 230 samples
Iron 348 samples
Nitrate 53 samples
Arsenic 156 samples
Lead 157 samples
Chloride 379 samples
Fluoride 220 samples
Sulfate 251 samples
Sodium 242 samples
pH 179 samples
Hardness 70 samples
Limited data (<15 samples) — interpret with caution
HFPO-DA (GenX) 11 samples
Nitrite 10 samples
PFNA 11 samples
PFOA 11 samples
PFOS 9 samples
Radon 1 sample
Uranium 1 sample
Public vs. Private Water in Morrison County
97Active public water systems
24,979Residents on public water
54%Households on private wells
Public water systems in Morrison 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 Morrison 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 Morrison 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 Morrison County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Morrison 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 Morrison County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Morrison 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.