The decision was made by Durham Council in a closer-than-expected vote at around 2 a.m. after hearing from 70 citizen delegations, with all but a handful opposed to the project.
The last of three motions passed 16-12 after several hours of tense and sometimes bitter debate.
Proponents said it's a better option than continuing to ship garbage to Michigan or opening a local landfill, while foes of the project pointed to potential impacts on human health and ecological damage from toxic emissions and greenhouses gases.
And bottom ash from the process will still have to be shipped across the border to a dump in New York State.
The incinerator will not pose unacceptable risk to humans living in the area around Courtice at Highway 401, according to the environmental assessment that was done, but medical officer of health Dr. Robert Kyle stopped short of saying there is no risk.
Covanta Energy Corporation of New Jersey has been chosen to design, build and operate the project, but some councillors and citizens questioned their record of pollution and labour relations in the U.S. The facility is expected to open in 2013 if final approval is received.
The plan is to incinerate up to 140,000 tonnes of "residual garbage," left after recycling, including 20,000 tonnes a year from York Region, which will fund about $50 million of the project subject to that council's final approval.