Section 304(b) of the Clean Water Act requires EPA to annually review and, if appropriate, revise its technology-based regulations, called 'effluent limitations guidelines and standards' or 'effluent guidelines.' These guidelines limit the discharge of pollutants to waters of the United States from various categories of industrial facilities. Every other year, Section 304(m) of the Clean Water Act requires EPA to publish a plan establishing a schedule for the annual review and revision of effluent guidelines required by Section 304(b). EPA last published an Effluent Guidelines Program Plan in 2004 (64 FR; 53705; September 2, 2004). During its 2005 screening-level analysis of discharges from categories with existing regulations, EPA determined that the Pulp, Paper, and Paperboard Point Source Category ranked higher than any other category in discharges of toxic and nonconventional pollutants. Because of these findings, EPA is conducting a more detailed study of this category. During this study, EPA will first verify that the pollutant discharges reported to PCS and TRI for 2002 accurately reflect the current discharges of the industry. EPA will also perform an in-depth analysis of the reported pollutant discharges, and as appropriate, will review technology innovation and process changes including a preliminary assessment of technology cost and affordability. Additionally, EPA will consider whether there are industrial sectors not currently subject to effluent guidelines or pretreatment standards that should be considered potential new subcategories of this category. The purpose of the detailed study is to determine whether it would be appropriate for EPA to revise the existing effluent guidelines. EPA's decision to conduct a detailed study on this category does not mean that EPA is required to revise its regulations for this category. EPA will make such a decision as part of the final 2006 Effluent Guidelines Program Plan.