TULSA, OK -- Poultry companies being sued by Oklahoma for allegedly polluting the Illinois River watershed want a judge to prohibit testimony of one of the state's expert witnesses in the case.
The companies say in a 431-page motion filed Friday in federal court that testimony offered by Valerie Harwood is unreliable and would be "confusing and unfairly prejudicial if presented to a lay jury."
But spokesman Charlie Price with the Oklahoma attorney general's office says such a filing is a normal pretrial motion and is not surprising.
Harwood is a professor at the University of South Florida who testified last year that she's identified a poultry litter-specific "biomarker." The biomarker reportedly traced a path that contamination from poultry waste travels from fields into the watershed.
The poultry companies point out in their motion that Harwood's work has been "severely criticized" and rejected by a leading journal.
A trial is expected to begin in September.