The purpose of this report is to summarize information EPA collected to assess drinking water treatment plant (WTP) discharges of treatment residuals to surface water. EPA identified WTPs for analysis in its 2004 Effluent Guidelines Program Plan based on public comments and preliminary review of available data. In addition to literature review and site visits, EPA collected technical and financial information about WTPs through a national survey. After considering extensive information about WTPs, the production and management of treatment residuals, the characteristics of residuals waste streams, and resource availability in the context of other priorities, EPA determined that discharges of treatment residuals are best addressed through National Pollutant Discharge Elimination System (NPDES) permits. Accordingly, this report provides information about drinking water treatment technologies and residuals best management practices that may be useful to NPDES permit writers and WTPs with NPDES permits. Sections 2, 3, 9, 10, and 11 of this report summarize the data that EPA collected. Sections 4 through 8 and Sections 12 and 13 provide technical information particularly relevant to NPDES permitting of treatment residuals.