Reading Rochester's 2025 Water Quality Report

Rochester's 2025 water quality report (PWS ID 1550010) covers water from 29 deep wells and lists no violations. Highlights: chlorine averaged up to 1.02 ppm, sodium peaked at 8.77 ppm, and PFOS and PFOA stayed under EPA's 4.0 ppt limits. Hardness, 17 grains per gallon, appears on RPU's water quality page rather than in the report tables.

Where the water comes from

The report describes a groundwater supply from twenty-nine wells, 389 to 981 feet deep, in the Jordan-Wonewoc, Prairie du Chien-Jordan, Prairie du Chien-Wonewoc, Jordan and Jordan-St. Lawrence aquifers. RPU also operates two small single-well systems, Meadowbrook Addition and Sandy Slopes Community, and each has its own report. Check your bill if you're unsure which applies to you.

The numbers worth knowing

• Chlorine: highest average 1.02 ppm (0.94 to 1.07), limit 4.0.
• Fluoride: 0.71 ppm, added under Minnesota's fluoridation law.
• Nitrate: 0.19 ppm, far under the 10 ppm limit.
• Sodium: up to 8.77 ppm, with a note that home softening raises it.
• Sulfate: up to 31.8 ppm.
• PFOS and PFOA: highest averages 1.95 and 0.8 ppt, limit 4.0 ppt each.
• Lead: 90th percentile 7.46 ppb against a 15 ppb action level, 1 of 50 homes above it. RPU notes some 2025 sample paperwork is under review with the Minnesota Department of Health.

How to read a table row

Each row pairs a measured level with two benchmarks. The MCL is the legal limit. The MCLG, or goal, is the level below which no health risk is known or expected, and it's often lower than the MCL, sometimes zero. For lead and copper, the benchmark is an action level applied to the 90th percentile of home samples, meaning 90% of homes tested at or below that number. The range column shows the lowest and highest single results, and a final column says whether there was a violation. For every row in Rochester's 2025 report, it says no.

Service lines

As of October 2025, RPU's inventory counted 257 lead service lines, 269 galvanized lines needing replacement, 2,546 of unknown material and 39,002 non-lead. You can look up your address through the Minnesota Department of Health's lead inventory tool, as the report explains.

Why hardness isn't in the tables

The report's tables cover regulated and unregulated contaminants. Hardness is neither; it's a nuisance, not a health standard. RPU publishes it on its water quality page instead: 17 grains per gallon, or 280 ppm, which RPU links to the limestone bedrock under the city. That figure is what matters for sizing a water softener. If chlorine taste is your main complaint, a whole-house filter is the better fit. Typical costs for both are on the Rochester cost page.