Full contaminant data, sample history, and sourcing for Rice County. For readers who want to go beyond the summary.
Contaminant Data — All Analytes
173 well testing events on record, covering
22 analytes.
Data spans 1955 to 2024.
Contaminant
Samples
Years
Detection Rate
Distribution LowModHigh
vs. Limit
vs. MN Avg
Iron
139
1963–2025
89%
412% of limit
↓ 42% below
Manganese
139
1963–2025
87%
260% of limit
↓ 47% below
Arsenic
109
1992–2025
51%
127% of limit
↑ 48% above
Lead
110
1980–2025
32%
159% of limit
↑ 257% above
PFOA
municipal
24
2007–2025
33%
188% of limit
↓ 56% below
PFOS
municipal
20
2023–2025
25%
31% of limit
↓ 84% below
Sulfate
141
1963–2025
97%
7% of limit
↓ 65% below
Chloride
150
1963–2025
100%
1% of limit
↓ 89% below
Fluoride
124
1963–2025
64%
6% of limit
~ typical
HFPO-DA (GenX)
municipal
16
2023–2025
0%
—
—
Nitrate
100
1963–2018
38%
0% of limit
↓ 99% below
Nitrite
74
1993–2018
26%
0% of limit
↓ 75% below
PFHxS
municipal
14
2023–2025
7%
80% of limit
~ typical
PFNA
municipal
17
2007–2025
0%
—
—
Radon
5
1996
100%
12% of limit
↓ 77% below
Uranium
9
1996–2018
67%
5% of limit
↑ 25% above
Total Coliform
2
2000–2018
40%
—
~ typical
E. coli
2
2000–2018
0%
—
—
Hardness
21
1963–2018
100%
—
~ typical
PFBS
municipal
13
2023–2025
0%
—
—
pH
20
1963–2018
100%
—
~ typical
Sodium
139
1963–2025
100%
—
↓ 71% 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 Rice County
Of the 109 arsenic tests on record for Rice County (1992–2025),
49% found none, and half were below 0.29 µg/L.
Of the 150 chloride tests on record for Rice County (1963–2025),
0% found none, and half were below 2.13 mg/L.
Of the 124 fluoride tests on record for Rice County (1963–2025),
36% found none, and half were below 200 µg/L.
Of the 139 iron tests on record for Rice County (1963–2025),
11% found none, and half were below 980 µg/L.
Of the 110 lead tests on record for Rice County (1980–2025),
68% found none.
Of the 139 manganese tests on record for Rice County (1963–2025),
13% found none, and half were below 107 µg/L.
Of the 100 nitrate tests on record for Rice County (1963–2018),
62% found none.
Of the 141 sulfate tests on record for Rice County (1963–2025),
3% found none, and half were below 16 mg/L.
Data Coverage & Gaps
Well-sampled analytes (15+ samples)
Iron 139 samples
Manganese 139 samples
Arsenic 109 samples
Lead 110 samples
PFOA 24 samples
PFOS 20 samples
Sulfate 141 samples
Chloride 150 samples
Fluoride 124 samples
HFPO-DA (GenX) 16 samples
Nitrate 100 samples
Nitrite 74 samples
PFNA 17 samples
Hardness 21 samples
pH 20 samples
Sodium 139 samples
Limited data (<15 samples) — interpret with caution
PFHxS 14 samples
Radon 5 samples
Uranium 9 samples
Total Coliform 2 samples
E. coli 2 samples
Public vs. Private Water in Rice County
70Active public water systems
64,781Residents on public water
28%Households on private wells
Public water systems in Rice 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 Rice 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 Rice 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 Rice County. Census data explorer →
USGS Aquifer Atlas — principal aquifer type underlying Rice 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 Rice County, used in contamination risk scoring. TRI Explorer →
EPA Superfund NPL — National Priorities List sites in or near Rice 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.