The Peaks to Portland fundraising swim will go on as scheduled Saturday.
On Thursday about one million gallons of partially-treated sewage from the city's wastewater treatment plant spilled into Casco Bay.
Dave Madore of the Maine Department of Environmental Protection says the primary concern is bacteria in the water.
“The cove itself has a high dilution rate, so with one time behind it, a lot of that is going to move out and away. It may take some time for that to actually move out,” says Madore.
Portland officials said a water quality sample shows bacteria levels are well below the state beach closure limit. The city says a routine advisory will be posted at the beach.
The city reopened the East End beach after a second batch of water sample tests was completed on Friday.
The YMCA said earlier Friday that it was "anticipating that the race will proceed" as it awaits official test results. It then announced that the race would go on.
The Portland Water District is expected to submit a report about the incident within a few days.
Updated 4:41 p.m.