We've just started getting all of our toner from a pretty cool WA company - Magnum Print Solutions www.magnumlaser.com. They have a facility in Seattle that recycles toner on site - no middle man, and no shipping back and forth between the US and Asia. I must admit, I've never looked too closely at how toner is "recycled" until I found out about these folks - it's one of those things that people probably rarely think about but I would propose that it is one of the most un-environmental products in our stores becuause of their carbon footprint.
I've attached the fact sheet from Magnum about their toners, and we've started using them in all of our HP printers, including our printers we use to print high-quality graphics/posters/brochures/etc. They have fantastic customer service, their pricing is awesome, and for us they are a local company (only about 90 miles away) - they even re-use the toner boxes an average of 30 times (which are also made locally).
I'm very happy so far with our switch to this company - a co-worker's partner went to visit the facility (which is how I heard about them) and was very impressed as the employees had nothing but good things to say, are being paid fair wages and feel like they are cared for, and generally feel very good about the impact they are making on the environment.
I encourage you to contact them to see if this is a viable solution for your store(s)!