The biggest problem with landfills is the fact that the rubbish removal taken to landfills is digested under ANAEROBIC CONDITIONS! This means that the breakdown of the rubbish removal takes place under conditions that LACK OXYGEN.
By contrast, the rubbish removal we put in a compost pile is digested under AEROBIC CONDITIONS! This means that the breakdown of the rubbish removal in a garden variety compost pile, versus a landfill, takes place under conditions with PLENTY OF OXYGEN.
Why do ANAEROBIC CONDITIONS (no oxygen) versus AEROBIC CONDITIONS (lots of oxygen) matter so much?
Rubbish removal is broken down by microorganisms, both at the landfill and in a garden compost pile. The key difference between the two decomposition processes is in the type of microorganisms that break down the rubbish removal. In a landfill, the microorganisms that break down the rubbish removal are the type that can survive in conditions that LACK OXYGEN (this exists in nature but is far less common). In a garden compost pile, on the other hand, the microorganisms that break down the rubbish removal require the presence of oxygen to survive, as most organisms on Earth do!
So, the key difference between a landfill and a garden compost pile is:
Anaerobic microorganisms VERSUS Aerobic microorganisms
(which depends on the lack or presence of oxygen)
Now, you are probably wondering why landfills are devoid of oxygen and why garden compost piles are full of oxygen?
Compost piles have pockets of air between the decomposing particles! These pockets of air contain oxygen! In fact, this is why you are supposed to stir your compost pile about once a week. The stirring process introduces fresh air in the form of new air pockets which replenishes the oxygen supply in the compost. This makes the aerobic microorganisms doing the decomposition happy and they continue doing their decomposition activity. Earthworms burrowing through the compost and breaking up the particles through digestion also help create new oxygen filled air pockets between the compost particles.
Landfills are HUGE compared to garden compost piles. Their layers run DEEP. Rubbish removal gets deposited so often, layers upon layers upon layers are created on a weekly basis. The weight of all this rubbish removal packs the layers down so densely that no air pockets exist, and therefore, no oxygen exists. Any oxygen initially in a fresh layer gets quickly used up, any aerobic microorganisms present in the top layer quickly die off, and another layer of waste removal is dumped on top of the fresh layer, making it now part of the ANAEROBIC graveyard of rubbish removal we find in landfills!
Landfill operators also use machines to pack these layers down so they can fit more rubbish removal into the landfill. Why is this? It’s more profitable for one thing! It’s also more “efficient” in terms of the land space devoted to rubbish removal.
Now, you may also be asking why it matters whether rubbish removal is broken down by anaerobic microorganisms versus aerobic …