The method described here was prepared by the Joint Task Group for Method 5910. It will be included in the nineteenth edition of Standard Methods but is being published now so that it will be available for use with the Information Collection Rule. The method is intended to indicate the aggregate concentration of UV-absorbing organics, which may possibly be correlated with percursors of disinfection byproducts. Details of the experimental method, results and discussion, and quality control are included, as well as a description of the prinicple of the method and interferences. Interlaboratory precision data are shown. Includes 22 references, tables.