How does one compare the environmental consequences of alternative actions?

For instance, if a jar is a mess and needs to be cleaned to be recycled.. To clean it will use a lot of soap and water, which as we all know has its own issues. So if I recycle, I spread soap/phosphates and run off water. If i don't, I add to the landfill situation. Burns me up trying to figure the right thing to do. Please help.