Q: Scott wrote: How can I tell what container size we currently use?

A: There are a few ways to define the size of a container. One rule is, don't trust the spray painted number on the side. That was put there by the garbage company and may/may not be correct.
The first thing I would do is look for the sticker on the container that contains the manufacturers name, phone number and the serial number of the container. Call the manufacturer, give them the serial number and who the garbage company is that provided it. They will be able to tell you exactly what size it is. 
Secondly, you can call another local garbage company in your area and have a sales or operations guy come out and tell you. With this option comes the annoying phone calls etc associated with them thinking you want to switch providers. This option works well because chances are great that all the local garbage companies bought from the same or similar manufacturers based on geography. 
The third option would be to measure the container and figure it out. This option is not the best use of your time but I explain how you can do it in my ebook and also provide you with a chart of all the standard containers and their dimensions as a reference guide.

Hope this was helpful.

Ed