Last year the American River in Sacramento was put on California's list of impaired waterways because of elevated E. coli levels. Around 20 percent of the tests along the lower portion of the river were found to have unsafe amounts of the bacteria since January.
But last week safe results were reported at all test sites, said Adam Laputz with the State Water Resources Control Board, which runs the testing program.
“It's certainly is encouraging that the levels are lower, but the reality is we've seen high levels of E. coli over the years,” Laputz added.
Still, he says safe levels don't necessarily remove risk of sickness.
“We don't right now know what the sources are. E. coli is an indicator of fecal pollution,” Laputz said. “Until we really have a handle of what those might be, it’s hard for us to make decisions on how do we reduce those sources."
Even though the levels are lower, county officials still advise using caution when swimming in at least four spots at Discovery Park. The caution includes avoiding algae blooms, to not drink the water and to shower after swimming. So far no illnesses have been reported.