Drinking water quality · 2025
· Verified
What's in Rochester, MN tap water
21 contaminants were measured in the Rochester, MN water system's 2025 annual report. Each is shown below against its federal limit — 1 sit at or above that limit.
- Reporting year
- 2025
- Contaminants measured
- 21
- Over federal limit
- 1
- Approaching the limit
- 0
- Worst contaminant
- Lithium
- Service area
- MN
PFAS — EPA UCMR5 (2023–2025)
2 PFAS compounds detected in Rochester, MN
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFHxS (Perfluorohexane sulfonic acid)
● Below limitbelow national p90 (12.049999999999997 ng/L across detecting U.S. systems)
Lithium
● Detected (no federal limit)below national p90 (76.59999999999991 mg/L across detecting U.S. systems)
Where your water comes from · EPA SDWIS
Rochester, MN's drinking water comes from ground water, drawn from 30 sources.
Source
- WELL · 29
- WELL #33 ROSE HARBOR
Treatment
- Well #11 Entry Point
- Well #12 Entry Point
- Well #13 Entry Point
- + 27 more
Distribution
Historical readings · EPA Six-Year Review (2012–2019)
17 historically-detected contaminants in Rochester, MN
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
GROSS ALPHA worst: 2013 | 13 pCi/L 87% | 15 pCi/L | '12'13'14'15'16'17'18'19 |
CYANIDE worst: 2013 | 0.12 mg/L within near national p90 | 0.2 mg/L | '13 |
FLUORIDE worst: 2014 | 1.3 mg/L within | 4 mg/L | '12'13'14'15'16'17'18'19 |
PCE worst: 2017 | 0.0015 mg/L within | 0.005 mg/L | '12'13'14'15'16'17'18'19 |
TCE worst: 2017 | 0.00057 mg/L within | 0.005 mg/L | '14'15'16'17'18'19 |
NITRATE NITRITE worst: 2017 | 0.77 mg/L within | 10 mg/L | '12'13'14'15'16'17'18'19 |
BARIUM worst: 2017 | 0.105 mg/L within below national p90 | 2 mg/L | '12'13'14'15'16'17'18'19 |
CHROMIUM worst: 2014 | 0.00033 mg/L within below national p90 | 0.1 mg/L | '14 |
TOLUENE worst: 2014 | 0.00024 mg/L within | 1 mg/L | '14 |
COPPER worst: 2013 | 1.71 mg/L above national p90 | — | '13'16'19 |
LEAD worst: 2013 | 0.0298 mg/L | — | '13'16'19 |
DBAA worst: 2014 | 0.001 mg/L | — | '14 |
DCAA worst: 2012 | 0.0064 mg/L | — | '12'13'14'15'16'17'18'19 |
TCAA worst: 2012 | 0.0018 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMODICHLOROMETHANE worst: 2012 | 0.0033 mg/L | — | '12'13'14'15'16'17'18'19 |
CHLOROFORM worst: 2012 | 0.014 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.0019 mg/L | — | '12'13'14'15'16'17'18'19 |
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SodiumA naturally occurring salt component. | 8.77MaximumAverage Result or Highest Single Test Result | 20MCL | Within the limit |
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChlorineA disinfectant added to drinking water to kill bacteria and viruses. | 0.94–1.07Rangeof Detected Test Results | 4MCLG | Within the limit |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 4.4–16Rangeof Detected Test Results | 80MCL | Within the limit |
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 1.2–5.5Rangeof Detected Test Results | 60MCL | Within the limit |
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| SulfateA naturally occurring mineral from rock and soil. | 31.8MaximumAverage Result or Highest Single Test Result | 500MCL | Within the limit |
| NitrateA compound from fertilizer runoff, septic systems, and erosion of natural deposits. | 0.19MaximumAverage or Highest Single Test Result | 10MCLG | Within the limit |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Perfluorobutanesulfonic acidPerfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' | 0.55MaximumAverage Result or Highest Single Test Result | 100MCL | Within the limit |
| Perfluorohexanoic acidPerfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' | 0–0.89Rangeof Detected Test Results | 200MCL | Within the limit |
| PFBAPerfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' | 0–3.4Rangeof Detected Test Results | 7000MCL | Within the limit |
| 6:2 Fluorotelomer sulfonic acid (6:2 FTS)6:2 fluorotelomer sulfonic acid, a PFAS-related compound. | 1.2MaximumAverage Result or Highest Single Test Result | None set | Detected — no federal limit |
| Perfluoropentanesulfonic acid (PFPeS)Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' | 0–0.45Rangeof Detected Test Results | None set | Detected — no federal limit |
| PFOAPerfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. | 0–0.97Rangeof Detected Test Results | 0MCLG | Detected — no federal limit |
| PFOSPerfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. | 0–2.7Rangeof Detected Test Results | 0MCLG | Detected — no federal limit |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | 4.9MaximumAverage or Highest Single Test Result | 0MCLG | Detected — no federal limit |
People also ask about Rochester, MN's water
+Is Rochester, MN tap water safe to drink in 2025?
The 2025 Consumer Confidence Report for the Rochester, MN water utility lists 1 contaminant at or above the federal limit: Lithium. Whether that means the water is "unsafe" depends on which contaminant, how long the exposure, and individual health factors. The table on this page shows the measured value, the federal threshold, and the regulated statistic used for compliance.
+What contaminants are in Rochester, MN tap water?
21 contaminants were measured in Rochester, MN's 2025 Consumer Confidence Report, spanning pfas ("forever chemicals"), metals, and inorganic chemicals. 19 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Which contaminants exceed federal limits in Rochester, MN tap water?
One contaminant in Rochester, MN's 2025 report sits at or above the federal limit: Lithium (1.1× the limit). The EPA enforces these limits against the regulated reporting statistic — typically a running annual average or 90th percentile — not a one-off sample spike.
+What is the worst contaminant in Rochester, MN tap water?
The contaminant with the highest measured value relative to its federal limit in the 2025 report is Lithium, at 1.1× the federal threshold. It belongs to the metals family of contaminants.
+Where does the data on this page come from?
Every value is transcribed from Rochester, MN's 2025 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Rochester, MN's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2025 report; a new report will replace it once the utility publishes its next annual update.