Raising billions of animals for slaughter each year also means producing an exorbitant amount of waste. Factory farms in the United States produce more than 500 million tons of manure annually according to the EPA. Today, fewer farms are raising more animals and factory farms are spreading manure in concentrated open-air pools, called manure lagoons. Often as big as several football fields, these lagoons are prone to leaks and spills and can devastate nearby lands and communities by polluting the surrounding ecosystems, air, and water. In 2011, an Illinois hog farm spilled 200,000 gallons of manure into a creek, killing more than 110,000 fish.
When lagoons reach capacity, farmers will often opt to apply manure to surrounding areas rather than pay to have the waste transported off-site. According to the USDA, animal waste can contaminate water supplies and emit harmful gases into the atmosphere when over-applied to land.
In order to prevent the spread of disease in the crowded, filthy conditions of confinement operations, and to promote faster growth, producers feed farm animals a number of antibiotics. Upwards of 75 percent of the antibiotics fed to farm animals end up undigested in their urine and manure. Through this waste, the antibiotics may contaminate crops and waterways and ultimately be ingested by humans.