They're pretty much as popular in Canada as the US. We had one way way back in the 60's in our house as did many neighbours and they're still widely available at HD and Sears etc. But back to the question, if you have green bin recycling for kitchen waste then it's kinda pointless to install a garburator. Actually why are you giving away your kitchen waste when you can compost it yourself in your own backyard and get free soil, unless of course you're in an apt or condo or something

I compost all grain, fiber, and vegetable leftovers in the house. You should not compost animal products, however. So you still may have some material for the garbage disposal. I have a disposal, but have to admit it's there more because people expect one than because I have a lot to send down the disposal.

The green bin organics program will take all compostables, including meat scraps. You should not use a garbage disposal, after all, you have one of the best municipal organics collection programs around.