PORTLAND, Ore. (KOIN) — How safe is it to swim in the Willamette River?

The Bureau of Environmental Services told KOIN 6 News it’s perfectly safe.

BES has been testing 5 different areas, including the Willamette River, for E. coli every week since mid-May. The bacteria is the primary polluter that could cause health problems for people who swim or make contact with the water for extended periods of time.

The Department of Environmental Quality’s safety threshold for E. coli is 406 colonies per 100 milliliters of water. Environmental monitoring manager Peter Abrams said the latest results came back well below that number.

Officials attribute the water quality upgrade to the completion of a $1.4 billion Big Pipe Project that was completed 6 years ago to reduce combined sewer overflow.

“The river is a complex system,” Diane Dulken with BES said. “Levels of other contaminants are low, but there’s still work to be done.”

While bacteria levels in the river are OK now, there are other things swimmers should consider before jumping into local waterways this summer.

“[The river] is not a pool, this is colder,” Lt. Rich Chatman with Portland Fire & Rescue said. “There is no visibility in there, and there’s also a current.”Click here to check weekly water temperatures and bacteria test results.