Chicken consumption has more than doubled since the 1970s, according to a new study by the Pew Environment Group.
But the report says the manure produced by all those chickens can seep into waterways, fostering algae blooms and oxygen-deprived dead zones.
The Chesapeake Bay Foundation says this is especially true of chicken farms in Delaware, Virginia and Pennsylvania.
The study recommends capping the number of chickens at farms if farmers can't find methods to deal with their waste.
But poultry producers say they're already taking significant steps to improve the industry's environmental impact. They also point out the waste is full of nutrients that are good for crops.