Brimley State Park is a Great Lakes beach in Chippewa County, Michigan. Across 555 bacteria samples collected between 2021 and 2025 at nearby monitoring stations, it earns a Beach Safety Grade of C — Fair.
About 11% of samples at Brimley State Park exceeded the EPA Beach Action Value of 235 CFU/100 mL for Escherichia coli — the threshold at which water managers typically post a swimming advisory. In practice that means the safe-swimming limit was sometimes crossed here over the monitored period. Bacteria samples occasionally exceed the safe-swimming threshold — check the latest advisory before swimming.
The evidence behind this grade is deep for a beach page: 555 results from 13 monitoring stations, spanning 2021 to 2025. Enough sampling, from enough places, over enough seasons that one bad week can't drive the letter.
Brimley State Park was not under a swimming advisory in the most recent EPA snapshot. Conditions can change quickly after heavy rain or high runoff, so it's still worth checking the current advisory the day you go.