The Office of Science and Technology (OST), housed within U. S. Environmental Protection Agency's (EPA's) Office of Water, uses sound science, engineering and public policy to protect and restore the nation's water quality. OST advances water quality, public health and environmental protection under the Clean Water and Safe Drinking Water Acts by: (1) Producing regulatory guidelines and analytical test methods; standards and criteria recommendations; advisories for beach swimming, fish consumption, and drinking water; risk assessments and special studies identifying needed regulations; and models and tools. (2) Setting national water quality goals and providing tools to measure progress in reaching them. (3) Ensuring federal and state water programs reflect current scientific knowledge about water pollution causes and impacts on human health and ecosystems. Collectively, OST's responsibilities help water program managers protect aquatic environments and human health.