Im pretty sure a space colony of some sort would re-cycle most of their waste materials, in space, everything is precious.
Organic matter, from feces to plastics will without a doubt be re-used. Waste chemicals from chemical plants would probably be stored for later recycling. And then we have waste gas, wich is either stored for later use, or released into the open to be stripped away by the sun.
Even if people litter and leave stuff behind, there are no lifeforms that would care, expect the company owners that might be using that that surface for mining and resource extraction. If we drop plastic and waste chemicals in a mine or quarry, the material and minerals being extracted might contain impurities, wich is not what anyone wants. People won't drop chemicals into places with water, we use for consumption. The water is most likely in the form of ice, so it won't flow anywere else, wich is bassicly the main reason people pour chemicals in water on Earth, so it flows away. There is no good reason to do that in space, unless you want to mess up another colony's economy.
Remember, in space, people live in confined spaces instead of in one common space that is the Earth's atmosphre, wich is a good thing, because if Colony A on the North Pole accidentally releases toxic chemicals in their living space, all the other colonies are pretty safe, if this happend on Earth, then everyone is affected. Pollution is alot different in space than on Earth.
I do believe we should keep our hands of places like Europa, with possible subsurface oceans. Any place with safe (not the extremely salty stuff nothing can survive in) liquid water should not be used for resources. We need to keep the microbe rights activists (aka Planetary Protection Officers) happy, and preserve the microbes.