About a year or so ago, Microsoft's campuses made a huge switch from all plastic cups/silverware to compostable materials. Silverware/cups literally made out of corn and potatoes and such. A common question was "why doesn't MS just give each employee a ceramic mug?" The response was that MS found it's actually more environmentally damaging to wash them than it is to compost a crap load of cups. I found that response interesting. I'm not claiming that response was true (it might have just been compostable cups were cheaper for MS). But I am often surprised to find intuition and the environment don't always go hand in hand.