TULSA, Okla. (AP) — A study by the state of Oklahoma showing phosphorous pollution in a sensitive watershed was incomplete, rife with errors and "not scientifically defensible," a scientist testified Thursday in federal court.
The testimony targeted Oklahoma's closely watched case against 11 Arkansas poultry companies in a trial that began in September and is expected to run several more weeks.
Scientist Victor Bierman, an expert witness for the poultry companies, centered on a report by state expert Bernard Engel, a Purdue University professor who tried to estimate the tons of poultry manure dumped in the Illinois River watershed each year and its effect on the environment.
The watershed, which straddles Oklahoma and Arkansas, is among the areas where much of the nation's poultry production is concentrated.
Bierman, a scientist with LimnoTech, a Michigan-based environmental consulting firm, described numerous deficiencies with the data. Among them: missing files, different versions of reports showing different test outcomes and one report that left out half of the 1 million-acre watershed.
Engel sent two follow-up reports to correct the errors, but each had different numbers and new outcomes — results that Bierman said raised a "red flag" among his colleagues, who were hired by the poultry companies to examine how Engel arrived at his conclusions.
Bierman told U.S. District Judge Gregory K. Frizzell that Oklahoma's model "can't tell the difference" between real amounts of phosphorous and "numbers that are completely made up."
"The results are not scientifically defensible," Bierman testified. "They're not valid and they're simply not reliable."
Oklahoma sued the poultry industry in 2005, accusing it of polluting the watershed with tons of chicken manure, which has been used by area farmers as a cheap fertilizer for decades.
The state claims the chicken waste runs off farm fields and into area lakes and streams, posing a health risk to the tens of thousands of people who use the river each year.
The industry says it has acted responsibly and within the law in its handling of the waste.
The case is being monitored by other states that are considering challenges to the poultry industry. The state spent most of the past three months presenting its case.
The defendants named in the lawsuit are Tyson Foods Inc., Cargill Inc., Cal-Maine Foods, Inc., Tyson Poultry Inc., Tyson Chicken Inc., Cobb-Vantress Inc., Cargill Turkey Production L.L.C., George's Inc., George's Farms Inc., Peterson Farms Inc. and Simmons Foods Inc.