It may surprise you to know that the garbage that leaves your house will be preserved for centuries—in a landfill. More than a dump, landfills are an engineered storage system.

On the bottom, there’s a thick plastic membrane and a layer of compacted clay, to keep liquids from entering the groundwater.

Above that, the fill area is divided into cells for each day’s garbage. As trucks dump garbage into the cell, it’s compacted to become as small as possible.

At the end of the day, the cell is closed off with a layer of soil, and perhaps another layer of plastic, making it water- and airtight.

Most garbage won’t break down in this environment, though anaerobic bacteria will digest food and organic waste and produce methane, also known as natural gas, the same kind you burn in your stove.

Because it’s flammable, the methane has to be flared off. Or it can be collected and sold for industrial use. Or used to run electric generators at the landfill.

America leads the world, by a wide margin, in garbage production, with more than 1400 lbs per person per year. More than half of it ends up in landfills.

And 65 percent of that is packaging: cardboard, paper, plastic, bottles, and cans—nearly all of which could have been recycled.

On average, recycling costs about half as much as storing garbage in a landfill. So if you’d like to reduce your garbage footprint and your city’s municipal waste cost, recycling is the way to go.