A jointly funded study by the American Water Works Association Research Foundation and the Water Environment Research Foundation is available from AWWA. Factors Affecting the Formation of NDMA in Water and Occurrence enhances current knowledge of NDMA (N-nitrosodimethylamine), classified by the U.S. EPA as a probable human carcinogen. It is suspected that chlorination and chloramination may be contributing factors in NDMA formation in drinking water. The study surveys the levels of NDMA in selected drinking water, recycled water and wastewater. The research describes how NDMA forms in drinking water and the role played by chlorination and chloramination. It also examines the impacts of various water and wastewater treatment processes on NDMA formation.www.awwa.orgcustsvc@awwa.org