Is Cottage Grove, MN tap water safe?
Data: U.S. EPA · How we read the data · How we check it
Summary
No federal limits exceeded in EPA data for Cottage Grove Water System. 2 PFAS were detected below the limits.
Cottage Grove Water System supplies Cottage Grove (42,760 people).
Water system
Cottage Grove Water System
42,760 people · Groundwater · EPA ID MN1820004
Buys treated water from Saint Paul Park Water System.
| PFAS | Highest average | Limit |
|---|---|---|
| PFOA Not detected | – | 4 ppt |
| PFOS Not detected | – | 4 ppt |
| PFHxS Not detected | – | 10 ppt |
| PFNA Not detected | – | 10 ppt |
| HFPO-DA (GenX) Not detected | – | 10 ppt |
ppt = parts per trillion. "Highest average" is the highest average at any of the system's entry points, the way EPA compares results with the limits.
Lead: 3 ppb at the 90th percentile (Jun 2026, and 9 in 10 homes sampled were at or below it) Below action level
Health-based violations since 2016: 0
Across Minnesota, 10 of 197 water systems EPA tested had PFAS above a 2024 federal limit, and 7 systems were above the lead action level in results from the last five years. Minnesota results.
Cottage Grove homes and lead pipes
Lead service lines and lead solder were allowed until 1986, so homes from before then are the ones to check. How to check your own line.
Housing: Census American Community Survey 2020–2024 5-year estimates for Cottage Grove city (tables B25034, B25003). Estimates for small places have a margin of error.
How nearby cities compare
| City | PFAS | Lead (90th pct.) |
|---|---|---|
| Woodbury 6 mi Saint Paul Regional Water Services | None above limits | 10 ppb |
| Inver Grove Heights 7 mi Saint Paul Regional Water Services | None above limits | 10 ppb |
| Rosemount 9 mi Rosemount Water System | None above limits | 3 ppb |
| Eagan 12 mi Saint Paul Regional Water Services | None above limits | 10 ppb |
| Oakdale 12 mi Saint Paul Regional Water Services | None above limits | 10 ppb |
| St. Paul 13 mi Saint Paul Regional Water Services | None above limits | 10 ppb |
Cottage Grove ZIP codes (1)
- 55016
Questions
Is Cottage Grove tap water safe to drink?
Cottage Grove Water System has had no health-based violations since 2016. Utility data can't show lead from your own pipes: if your home was built before 1986, test your tap. Your utility's annual Consumer Confidence Report is the official summary.
Who supplies water in Cottage Grove, MN?
Cottage Grove Water System, which serves 42,760 people.
Does Cottage Grove tap water have PFAS?
Cottage Grove Water System had 2 PFAS detected at least once in EPA's 2023–2025 testing, all with averages below the federal limits.
Do Cottage Grove homes have lead pipes?
Census estimates put 37% of Cottage Grove homes as built before 1980 (Minnesota: 52%). Lead service lines and lead solder were allowed until 1986, so older homes are more likely to have them. Cottage Grove Water System's service line inventory says what your line is made of. The only way to know for your home is to check the line where it enters the house and test your tap.
Source: U.S. EPA drinking water records and PFAS testing (UCMR 5). How we read the data.