The U.S. Department of Energy reimburses CDPHE for its Rocky Flats remedy oversight, environmental fees, and associated costs (e.g., sampling). In accordance with the terms of the Rocky Flats Legacy Management Agreement, CDPHE’s billable hours and other costs are charged to a specific grant. This is an example of the “polluter pays principle” of environmental law, where the responsible entity – not the State of Colorado – bears the cost for past releases to the environment. Many other federal facilities are managed this way, both in Colorado and across the United States.