Duel-Flushing System

I am taking this course right now, Environmental Ethics. Thought to myself "hey, maybe you should actually take advantage of your benefit of free classes and do something to keep yourself busy". So I decided to enroll in the first course of a Sustainability certificate. If anyone knows me, I believe passionately about being accountable and responsible (On a side note, I actually took a survey to determine my strengths and my top five were, in this order, Relator, Maximizer, Empathy, Input and Responsbility). By accountable I mean, doing what you believe, living your life in a way comparable to your values. So anyways back to my class... I've been so wrapped up in all these articles on global warming, the deforestation problems, new forms of renewable energy, etc. that every spare second some thought pops into my mind. Most recently I was reading about the fact that most people in the world have no or limited access to water. So I'm sitting on the toilet in my office building, I look up and I see this little diagram with instructions on how to flush the toilet. It's a duel-flushing system! In a nutshell, you flush up when you have "liquid waste", and down for solid. I think this type of technology is so great!! Love it! So on my way out of the restroom I stop in every stall to see if any other toilets come equipped with this service. None!! So in my attempt to be even more greener (as if a person who calls her man to test the relationship by asking whether or not he invests in compact fluorescent bulbs can be greener) I decide to commit myself to this lone stall! So I get back to my desk and my mind starts to wonder, and I'm left with these questions... If you're going to the restroom and you flush, who flushes up? It seems to be against common nature. Shouldn't the flush up be for solids, I mean who actually uses a public stall to drop solids??