Inside Climate News: Factory Farms in Iowa Generate 110 Billion Pounds of Manure Per Year. No One Tracks Where It’s Going.

Ninety-nine percent of farm animals in the U.S. are raised in CAFOs, which are typically characterized by shed-like structures that house hundreds to thousands of animals. Iowa alone is home to approximately 23 million hogs, nearly all of which are raised in confinement, and which produce an estimated 110 billion pounds of manure each year. While the Iowa Dept of Natural Resources requires farmers to documents their plans for spreading livestock manure, the agency doesn’t collect records of where and how much manure is actually spread. Manure is rich in nitrogen and phosphorus that fuel plant growth, but what’s not absorbed by plants can end up in waterways, triggering toxic algal blooms and high levels of nitrate in drinking water. Several studies have linked exposure to nitrate to elevated cancer risk. More DETAILS.