Temperature, Toxicity and Regulation: A Colorado Case Study

Temperature as a toxicity and regulated issue remains relatively un-discussed at the national level. In Colorado, State regulatory action directed at limiting temperature toxicity and updating previous standard's criteria has motivated at least one watershed group to start taking extensive aquatic temperature measurements to document the natural and anthropogenic nature of river/stream short and long term trends and variability. The aquatic temperature trends and fluctuations are measured in the South Platte River in the urban Denver, CO, area. We will discuss the rationale, methods and instruments used to collect a comprehensive data set that permits a more critical understanding of temperature in a river setting. While we will only look at a limited group of sites available, the methods and procedures could be used in almost any setting … urban or rural. We will also discuss Colorado's procedure for developing aquatic temperature criteria and the importance of having detailed data available when the regulatory process starts.