“The smell rolls in, almost like a fog,” said Dan Franks of his chicken-farming neighbors in Limestone County. “Big Chicken” producers are some of Texas’s worst polluters, and a new StateImpact Texas report delves into the growth of large-scale chicken farming in the state and its effects on the environment.

“It has been dubbed ‘Big Chicken‘: the revolution in how poultry is raised and processed. Chicken that once came from small, family farm operations is now produced by networks of huge chicken-growing complexes and sprawling processing plants,” Dave Fehling of StateImpact Texas wrote.

Late last month, an Environment Texas report revealed Sanderson Farms was the state’s biggest polluter, dropping more than 1.5 million pounds of pollution—mostly nitrates—into Texas’s waterways. In addition to the millions of gallons of wastewater, manure is swept into streams by rainwater, Fehling reported.

America’s appetite for chicken has doubled since 1970, and the chicken farming industry has grown in lockstep with this demand. Texas chicken farms raised more than six hundred million broilers in 2007, up from 260 million in 1988. This means that today there are five chickens in Texas for every person. This represents seven percent of the nation’s chicken supply, according to a July report by the Pew Environment Group. Only five states produce more chicken than Texas, making the state a member of the “Broiler Belt.” “In this area, which extends from eastern Texas through the southeastern United States and north to Maryland and Delaware, chickens outnumber people by as much as 400 to 1,” wrote Joshua S. Reichert, Managing Director of the Pew Environment Group.

Most of the state’s chickens are grown by contractors on smaller farms, who then hand over the grown boilers for processing at plants, Fehling reported. Environmentalists are concerned not just about the wastewater from the processing plants, but the millions of pounds of nitrate-packed chicken manure generated at the growers that then can wash into nearby bodies of water.

Under current state-level pollution control rules, chicken growers are considered “nonpoint” sources of pollution, Fehling wrote. “Nonpoint source pollution results when small amounts of contaminants from a large number of sources are carried by rainfall runoff into streams, lakes, or bays,” according to the Texas Nonpoint Source Management Program. “In contrast, pollution from point sources comes in large amounts from a single source, such as an industrial operation or a wastewater treatment plant. Pollution from most point sources is controlled through regulations that require treatment of a facility’s wastewater before it is discharged.”

The TCEQ and the Texas State Soil and Water Conservation Board are currently revising that management program, Fehling reported. Environmental groups want chicken operations to be considered point sources, which would mean they would face more regulatory scrutiny.