Elevated E. coli closes contact at two Grand Traverse beaches

East Bay Park was placed under a Level 3 advisory, meaning no body contact with the water, after testing found elevated E. coli in Grand Traverse County. Sunset Park was listed at Level 2, which allows only partial-body contact, and the county said both beaches would be resampled Thursday with results expected Friday.

The advisories affect two of the county’s most visible public recreation spots near Traverse City, where summer beach use shapes everything from family outings to weekend tourism. County officials said all other tested beaches remained at Level 1 and supported full-body contact recreation, a sign that the problem was limited to those two sites for now.

Michigan’s beach monitoring system allows local health departments to post advisories or closures when sampling shows contamination. State standards are based on E. coli levels designed to protect human health during recreation, and a beach can be posted when either the daily geometric mean or the 30-day geometric mean rises above the safe limit.

The state says beach testing is not just a one-sample snapshot. It uses geometric-mean criteria over one-day and 30-day periods, then keeps monitoring until bacteria levels fall back within acceptable levels and the beach can reopen. State officials also say contamination can come from wildlife waste, especially waterfowl, agricultural runoff, pet manure, wastewater spills, toxic algae and leaking septic systems.

Grand Traverse County’s beach-monitoring program covers five public beaches on East and West Grand Traverse Bay, with the Environmental Health Division working alongside the Watershed Center Grand Traverse Bay, the City of Traverse City and Traverse City State Park. That network is part of the county’s effort to keep the bayfront beaches open and safe through the busiest stretch of the season.

The latest advisories also fit a familiar pattern. The county’s beach-monitoring page shows repeated summer postings in 2025, including Level 3 and Level 2 advisories at Sunset Park and other beaches later in June and again in July, plus another Level 2 posting at Sunset Park in August. That history suggests Grand Traverse County’s beach-quality problems are not isolated, but part of a recurring summer challenge that can flare after weather events.

Heavy rain and high winds often push E. coli levels higher, adding runoff to the mix when the county is trying to keep public swimming areas open. For now, the most important question is whether Thursday’s resampling brings East Bay Park and Sunset Park back within standards by Friday, or extends the warning into another summer weekend on the bay.