The City of Toronto is gearing up to replace 141,000 of its water meter transmission units (MTU) after a large share of Toronto residents noticed their utility bills were doubled or even tripled in some cases. 

At a news conference on Thursday, general manager of Toronto Water Lou Di Gironimo revealed that thousands of its transmission unit meters had unexpectedly failed. 

"While it's common for one or two per cent of water meters and bills to have issues for several reasons annually, City of Toronto staff observed an increase in failures this past winter," Di Gironimo told reporters. 

"While the water meters themselves are working, it was confirmed the water Meter Transmission Units were failing at a higher rate than usual following further analysis and engagement with the supplier." 

Essentially, this means that the amount of water some Toronto residents are using is not being properly communicated back to the city, which has resulted in some people receiving hefty catch-up bills after not being charged for several months in a row.

The City installed approximately 470,000 meters over the past decade to automate billing, and Di Gironimo is now recommending that the city change all of the units (even the ones working), which could take anywhere from three to four years to complete. Fixing only the faulty units could take two to three years. 

So far, roughly 7,200 households have not received their utility bills in May and June, which has caused a delay in payment collection for the City. 

Residents can voice any concerns they have regarding their bills to a task force that can be reached by calling 311. Still, customers are expected to continue paying their estimated bills during the time that the transmission units get replaced. 

It's still not clear why the failure happened in the first place, and the City has not provided an estimate for how expensive replacing the units will be.