The number of farm factories and commercial livestock and poultry has been growing exponentially in the past decade.

Farm factories are unsightly and they smell. A government study found that living downwind from industrial hog operations reduced the property values of neighboring residential homes by approximately 10%.

But there is a bigger problem coming out of these farm factories.

Commercial livestock and poultry operations produce half a billion tons of manure each year, more than three times as much as that produced by the entire U.S. population. Such large quantities of manure stored at factories can emit “unsafe quantities” of ammonia, hydrogen sulfide and particulate matter and have become the fastest growing large source of the greenhouse gas methane.

This has led to Indiana Rep. Tom Saunders (R-Lewisville) to file an out-of-state manure regulation bill last week to curb the spreading of manure, especially near residential areas.

See below a map of the farm factory density for livestock, poultry and eggs in the U.S. as of 2007 by Factory Farm Map Project.

Click here to see the maps of farm factory density broken down by animal type >

Factory Farm Map

Source: Factory Farm Map Report (Nov 2010)