The Information Collection Rule (ICR), requires utilities that meet certain criteria to conduct disinfection byproduct presursor (DBP) removal studies. Under the ICR treatment study requirement, results from a total of 99 studies will be submitted, including 62 granular activated carbon (GAC) studies and 37 membrane studies. US Environmental Protection Agency (USEPA) is currently developing a data management system and a data analysis plan for the treatment study results, contructed as a database to organize the complex data sets generated during the treatment studies. This system will serve as the platform for higher level analyses to produce information that can feed into the development of the Stage 2 D/DBP regulation. The results from these studies will constitute an unprecedented database which will be used by USEPA and stakeholders to assess the feasibility and cost of using GAC and membrane technologies to control the occurrence of DBPs in a wide range of waters, and this information will be critical in evaluating the Stage 2 D/DBP Rule options. Includes 10 references, tables, figures.