Cottage Grove
Cottage Grove (EPA ID MN1820004) in Cottage Grove, MN supplies groundwater (wells) to about 42,760 people: no health-based violations since 2016, latest lead result 3 ppb, PFAS 2 detected.
No health-based violations reported since 2016.
90th-percentile lead in the latest round (Jan 2026). Lead comes mostly from household plumbing and service lines, so individual homes can be higher.
PFAS were detected, with PFOA and PFOS below 4.0 ppt (highest not detected).
Service area
EPA service-area boundary (state-supplied or EPA-modeled)System facts
Health-based violations
No health-based violations reported since 2016.
Lead
90th-percentile lead per sampling round (90% of the homes sampled were at or below this level). Black line: EPA’s 15 ppb action level; under the Lead and Copper Rule Improvements the action level becomes 10 ppb from 2027.
PFAS
| Compound | Highest result | Samples with detection | EPA limit |
|---|---|---|---|
| PFBA | 220 ppt | 7 of 10 | — |
| PFPeA | 6.4 ppt | 2 of 10 | — |
| PFDA | not detected | 0 of 10 | — |
| HFPO-DA (GenX) | not detected | 0 of 10 | — |
| PFOA | not detected | 0 of 10 | 4 ppt MCL |
| PFOS | not detected | 0 of 10 | 4 ppt MCL |
| PFNA | not detected | 0 of 10 | — |
| PFHxA | not detected | 0 of 10 | — |
| PFHpA | not detected | 0 of 10 | — |
| PFBS | not detected | 0 of 10 | — |
| PFHxS | not detected | 0 of 10 | — |
EPA Fifth Unregulated Contaminant Monitoring Rule (UCMR 5), samples 2023–2025; ppt = parts per trillion (ng/L). The 4.0 ppt maximum contaminant levels for PFOA and PFOS were set by EPA in 2024; water systems have until the end of the decade to comply.
ZIP codes served
ZIP codes whose center lies in this system’s service area.
What this is — and isn’t. These are records your water utility and state reported to the EPA, and the EPA’s radon map for your county. They describe the system and the area, not the water from your own tap or the air in your home. For that, read your utility’s annual Consumer Confidence Report and test: lead and radon tests are inexpensive.
Questions
Has Cottage Grove had drinking water violations?
No health-based violations reported since 2016.
What is the lead level in Cottage Grove water?
The latest 90th-percentile lead result (Jan 2026) was 3 ppb. EPA’s action level is 15 ppb (10 ppb from 2027).
Does Cottage Grove have PFAS in its water?
PFAS were detected, with PFOA and PFOS below 4.0 ppt (highest not detected).