How long does it take for a head of lettuce to decompose in a landfill? Really, give a guess out loud before scrolling down.
The answer? At least 25 years. Yeah, I know, its crazy! A University of Arizona project excavating landfills found a head of lettuce that was perfectly intact 25 years down in a landfill, and this wasn’t an anomaly. They found newspapers that were still readable from decades previous and all kinds of intact foods. You can read more about it in the book Rubbish! by William Rathje and Cullen Murphy which describes the project’s findings. The reason is, nothing biodegrades easily in a landfill. A well managed landfill seals off its contents like a tomb, often by piling dirt or another sealant on it. Biodegradation requires oxygen and microbes, both of which are in short supply in a landfill.
All those years, I had been scraping spoiled food and vegetable peelings into the trash thinking that, somehow, they would become dirt again one day. I never stopped to think how unrealistic this was considering they would be mixed in with everything else in a landfill–like motor oil, leftover medications, and other stuff you wouldn’t want in your garden soil. I never stopped to think that by scraping food into the trash, I was asking my kids, and their kids, and every generation after me to maintain those scraps in a landfill forever. Not super great parenting skills on my part!