This page provides information on EPA's approach to economic analysis when developing standards for drinking water contaminants. The three major components of compliance costs are treatment, monitoring and administrative costs. Treatment technologies remove or destroy pollutants such as arsenic, radon, disinfection byproducts and waterborne pathogens. To estimate treatment costs, U.S. EPA developed several engineering models using a bottom-up approach known as work breakdown structure (WBS). The WBS models derive system-level costs, and provide U.S. EPA with comprehensive, flexible and transparent tools to help estimate policy costs. Water Treatment Technology Cost Models and a Technology Overview section is available von this website.