Water Arbitrage

So today I decided to urinate in the law school, rather than at home, to save a little water. Imagine my chagrin, then, when I realized the law school urinals use one gallon per flush. That's not much less than a standard toilet, although it is still more efficient I suppose. Still, I think it could be much more efficient - a whole gallon! Ideally you would just have laser beams destroying the urine, thus using no water per flush.