The Colorado Division of Wildlife (DOW) has ruled out bird flu as the cause of death of about 375 ducks at Metro's wastewater treatment plant in Denver since early January.
"The deaths of these ducks continue to puzzle us all," said Steve Rogowski, director of operations and maintenance. "We are working with the Colorado Division of Wildlife and the US Fish and Wildlife Service to try to find the cause."
"Initially, we found ducks in the chlorine contact basin. However, our ongoing investigation has shown that ducks are dying in locations other than the chlorine basin, as well as on the South Platte River next to our site," said Rogowski.
"We've placed an emphasis on recovery of any sick ducks that we find," Rogowski said. As of today, Metro employees have turned 84 sick or injured ducks over to two DOW-approved rehabilitation centers.
Metro has also given DOW officers a number of specimens of dead ducks, which they have taken to the state's veterinary lab in Fort Collins to run tests.
The testing includes screening for a variety of diseases and toxicity-related issues.
"We hope we can get this problem resolved soon. Protecting the environment, including wildlife, is among our top priorities," said Rogowski.
The Metro Wastewater Reclamation District is the largest wastewater treatment agency in the Rocky Mountain West. It treats about 130 million gallons of wastewater a day and serves 1.5 million people in a 380-square-mile service area that includes Denver, Arvada, Aurora, Lakewood, part of Westminster, Wheat Ridge, and Thornton, together with about 40 sanitation and water and sanitation districts in the metropolitan Denver area.