The weather in Spain demands a lot of water consumption… and ends in a lot of empty plastic bottles. Here, you just throw them (preferably) in the plastic trash bin. In Germany it was the same until 2003. Back then, the government introduced a deposit system for plastic bottles and cans. So, every time you buy a drink, you have to pay up to 25 cents more for it. If you return the bottle, you get these 25 cents back.
You can imagine that no one was really excited about it because you need to bring the bottles back, but with the time I started to really appreciate this system. You can give the bottles back everywhere and the trash production has immensely declined. But you quite often forget to take all your bottles if you are going to the supermarket. Pictures like that are no rarity (especially students have this problem)
And if you are too lazy to bring them back or want to drink before a party and don’t want to carry your empty bottles all around, you can still just throw them away, because the few cents usually don’t hurt your purse. There are even people walking around in Germany that collect deposit bottles to make their money with that..
But a little more information: There are two different sorts of deposit bottles: Multi-usage (8 to 15 ct deposit) and one-way (25 ct deposit). The multi-usage, as the name already says, are cleaned and filled up again. The one way bottles are shredded and get recycled to new bottles.
Now imagine how much waste could be saved if every country would introduce a system like that? (also think about the logistical side, the trash does not have to be removed or taken away as the people do this job)