Adverse effects to Northern Shovelers from exposure to treated wastewater from Central Front Range, Colorado, wastewater treatment plants

From January through February of 2007, more than 900 waterfowl, the majority of which were northern shovelers (Anas clypeata), died in apparent association with prolonged exposure to water in or near treatment tanks at a number of wastewater treatment plants located along the central Colorado Front Range. Preliminary postmortem assessments were negative for waterfowl diseases, ingested toxins, or heavy metal contaminants. The probable cause of death for most of these mortalities was the induction of a fatal hypothermia resulting from the wetting of the ducks’ feathers. To test whether prolonged exposure of waterfowl to chemical compounds in secondary treated wastewater from municipal sources may play a role in the loss of waterproofing, [...]