Garbage does not get sorted after the collection truck picks it up. The same day it's picked up, it goes to the Cedar Hills Regional Landfill in Maple Valley. No one sorts the garbage to pull out recyclables or compostable material -- once something is thrown away, that material is gone for good.
Dozens of trucks a day dump their loads into open cells and bulldozers compress the material. When the cell is full, it's covered in dirt and left to decompose (very slowly - think centuries). Perforated pipes suck methane gas produced during decomposition to an onsite plant to produce energy. Other pipes route rainwater that gets contaminated from running through the garbage to leachate ponds where huge turbines froth the water so toxins will break down.
Because there is a limited amount of unoccupied land for landfills, and a finite amount of natural resources, it is important that everything put in the garbage are things that really cannot be recycled or composted. The city encourages all residents and businesses to take steps to prevent and reduce waste, and have goals for reducing the waste our community generates.