This Technical Practice Update (TPU) specifically examines the effect of wastewater treatment on some of the known or suspected microconstituents and the potential treatment technologies for their removal at wastewater treatment plants based on a survey of the literature. This is not to suggest that we should look solely to WWTPs to protect the quality of the water environment. Rather, a holistic approach involving source reduction and a variety of other strategies should be considered, as discussed more thoroughly in a WEF TPU on source control for microconstituents. This TPU includes the following sections: Background; Relevance of Issue and Technical Practice Update Objectives; What Has Been Done and What Do We Know; What Is Needed or Not Known; Where We Are Heading; Next Steps, and/or Recommendations; and References. Published by WEF. 2007. Electronic download. 17 pages.