(CNN) -- A paper mill in Louisiana is working closely with environmental officials to help determine what caused thousands of dead and dying fish to wash up along the banks of the Pearl River, a spokesman with the state Department of Environmental Quality said Monday.
Jeff Dauzat, a spokesman with the department, has confirmed that the plant, located in Bogalusa, Louisiana, did have a problem last Tuesday with the operation's wastewater plant. The plant exceeded its daily maximum for biological oxygen demand, which measures the amount of oxygen organisms used to break down waste.
WWL-TV, a CNN affiliate, reported Saturday night that Temple-Inland, the plant's owner, said it was possible that they exceeded the allowable discharge amount.
The plant, according to Dauzat, has been closed since Saturday while water samples are tested.
"We will compare samples to the facilities permit limit to determine if they were in compliance," Dauzat said. If the fish kill can be attributed to the paper mill, he said, "it could result in fines."
Results on water samples taken over the weekend are expected back in four to five days, environmental officials said.
The Louisiana Department of Wildlife and Fisheries called in emergency responders on Saturday after they began receiving calls about the large fish kill on Saturday, spokeswoman Olivia Watkins said.
Department biologists, working with the Department of Environmental Quality and other agencies in Louisiana, suspect that "a slug of partially treated or untreated wastewater reached the river and may have caused or contributed to the fish kill," Watkins said.
A news release from the department said "there is no impact on drinking from community water systems," according to the Louisiana Department of Health and Hospitals.
However, the statement said, health officials have advised that "people should not come in contact with discolored water in the Pearl River and never collect dead or floating fish to eat."
Dauzat agreed, suggesting that "people stay off the water" until the cause of the fish kill is determined.
Dead fish found along the Pearl River include paddlefish, American eels, catfish, bass, bluegill and shad, according to the Fish and Wildlife Service.