City staff are trying to determine if an estimated 33,000 litres of sanitary sewage spilled into the Ottawa River last month.
In a memo to council Monday, environmental services general manager Dixon Weir says the “suspected” spills might have come from the Hemlock combined sewage overflow site on April 21, 22 and 23.
The spills were recorded by equipment that was temporarily monitoring the sewer flow.
“The cause of these suspected spills is being investigated, but early indications are that these are not related to wet weather events, as all occurred during days without rainfall,” Weir wrote.
“Staff have implemented an enhanced level of site inspections given that our review of the sewers in the area do not indicate a cause or explanation of the recorded events.”
The city’s drinking water was unaffected, Weir wrote.