Watermain work that has reduced Queen Street West to one lane in each direction and forced a diversion of the 501 streetcar will continue for at least another month.

The work, which is taking place between Bathurst Street and Spadina Avenue, began in May and was scheduled to be completed by Oct. 9 but city officials now say it will likely continue until sometime in December.

According to Mayor John Tory, the delay is the result of water quality issues that were recently discovered during the course of testing that had to be undertaken before resurfacing and reopening the road.

“While I wish it were different and I wish this work was all done on time and on schedule I will not apologize for the fact that they are getting it right in terms of the water testing and making sure it is alright because once they close the street up then it is done and you would have to dig it back up again and people would be very critical of that,” Tory told reporters on Wednesday. “We will not compromise on water quality and water safety and that is what is being addressed right now.”

During the lane closures along Queen Street West, the 501 streetcar has been diverting along King Street between Shaw Street and Spadina Avenue.

Shuttle buses have also been operating to supplement service along the affected portion of Queen Street West.

Speaking with reporters at an unrelated transit announcement, Tory said that the water quality issues discovered by crews are not significant to the point that members of the public should be worried but, at the same time, must be dealt with right away.

“One of the only things more important than getting this job done efficiently and getting it done in such a way that eliminates the disruption for business and for public transportation is to make sure the water that flows through those water mains is safe,” he said.