The city is looking into the exact cause of a small spill at the Waste Water Treatment Plant Thursday morning.
At about 5 a.m., due to a technical issue, 3 metres cubed of unprocessed bio-solids was released from a holding tank at the Andrew Street site.
Superintendent of Environmental Services Joe Booth said the spill entered a storm catch basin leading to the St. Clair River, but the exact amount that entered the catch basin is unknown.
He said the Ministry of Environment Spills Action Centre has been notified and remediation efforts are underway, including the use of vacuum trucks on site.