OKLAHOMA CITY — Thirteen Arkansas poultry companies are accused in a lawsuit of polluting Oklahoma's water with chicken waste, but the case currently rests on scientific research that has been called into question as it nears a key hearing, according to The Associated Press.

Oklahoma Attorney General Drew Edmondson is relying on a microbiologist who says biological markers in the chicken waste allow her to track it from its source to the water supply, in order to prove that poultry waste and not something else is causing the water pollution.

Mr. Edmondson has been told by a federal judge, however, the research is not admissible unless other scientists find it reliable. And as Mr. Edmondson gets ready to appeal his case to the 10th U.S. Circuit Court of Appeals March 11, the research is being questioned. Marylynn Yates, an editor for Applied and Environmental Microbiology, wrote in a Jan. 23 e-mail obtained by AP the journal will not publish the science Mr. Edmondson's expert witness, microbiologist Valerie Harwood, uses to track the waste. Ms. Yates said Harwood didn't use proper controls and analyses and it's not clear if her work would be applicable to other regions, AP said.

Courts frown on evidence that hasn't been published in a peer-reviewed journal, said Lise T. Spacapan, chairwoman of the toxic torts and environmental law committee for the Chicago-based Defense Research Institute, an organization that defends businesses and individuals in civil litigation.

The U.S. poultry industry is keeping a close eye on this case. If a judge were to rule that applying poultry waste to the land ends up polluting the water, the industry could be faced with the expensive and difficult task of finding other ways to dispose of the waste. Middleman farmers and poultry growers in Oklahoma and Arkansas whose livelihoods are tied to the success of the industry also have a major stake.

If Mr. Edmondson were to win the case, it could set the stage for similar environmental lawsuits in other parts of the country.

Critics of the lawsuit against 13 Arkansas poultry companies say the journal's rejection of Ms. Harwood's research shows her methods are unreliable and casts doubt on whether chicken waste is the main cause of pollution in the 1 million-acre watershed. Companies named in Oklahoma's 2005 pollution lawsuit include Tyson Foods Inc., Tyson Poultry Inc., Tyson Chicken Inc., Cobb-Vantress Inc., Cal-Maine Foods Inc. Cargill Inc., Cargill Turkey Production L.L.C., George's Inc., George's Farms Inc., Peterson Farms Inc., Simmons Foods Inc., Cal-Maine Farms Inc. and Willow Brook Foods Inc.

To post your comments on this story, click here:

[email protected].