Take a dip at Mooney’s Bay or the Petrie Island River Beaches Tuesday but Ottawa Public Health says that swimming is “not recommended” at Petrie Island East Bay and Britannia. Water samples are collected daily from City of Ottawa supervised beaches between mid-June and the end of August and tested for E. coli bacteria. When tests find high levels of E. coli, it’s more likely that other disease-causing organisms are in the water, too, the health unit said.Those organisms can cause skin, ear, throat or gastrointestinal illnesses.