MINIMIZING ODORS FOR A NEW BIOSOLIDS PROGRAM AT CANADA'S LARGEST WASTEWATER TREATMENT PLANT

The City of Toronto, Ontario operates four wastewater treatment plants (WWTPs) in an urban environment of 2.5 million people. At the 820-megalitres per day Ashbridges Bay Treatment Plant, Canada's largest, the impending discontinuation of sludge incineration means the plant will lose its efficient and successful odorous air treatment system. Thus, an alternative method of odor control is required to treat emissions from existing and new sludge management facilities. The odor control system is mandated by both regulatory and public pressure to achieve non-detectable off-site odors. The challenge lays in finding an economic odor control system that will meet a stringent regulatory limit, survive intense public scrutiny, and be fully operational by 2001.