Oklahoma’s pollution case against the Arkansas poultry industry suffered another setback Wednesday, when a judge blocked the state from introducing soil test records that reportedly showed high phosphorus levels at 50 chicken farms.

Citing fairness, U.S. District Judge Gregory K. Frizzell instead ordered Oklahoma to hand over the complete soil test records for the operations going back to 1998, when the record-keeping began.

“I want to see the history,” Frizzell said, siding with poultry company attorneys who accused the state of “cherry-picking” tests showing higher pollution levels. “That’s why I want to see all the records, because they may cut either way here.”

Oklahoma sued 11 poultry companies in 2005, accusing them of polluting the Illinois River watershed in northeastern Oklahoma with tons of chicken manure. 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.

Ingrid Moll, an attorney for the state who initially argued for the admission of the records, said they helped tie the chicken farmers to the companies being sued and showed some cases where phosphorus levels had become excessive.

But poultry company attorneys objected to the state submitting only some tests and argued all the operations’ records should be turned over to the court.

Frizzell’s order came as Oklahoma wraps up its side of the case after nearly 35 days of testimony that stretched back to September. The closely watched trial is expected to run well into January.