On April 15, 1998, the U.S. Environmental Protection Agency (EPA) promulgated revised regulations for the pulp, paper, and paperboard category to control both effluent discharges and air emissions. The promulgation of the revised regulations marks the completion of the first of three phases of the Cluster Rules. As part of Phase I, EPA established effluent limitations guidelines and standards under 40 CFR Part 430 for the following two subcategories: Subpart B - Bleached Papergrade Kraft and Soda; and Subpart E - Papergrade Sulfite. At the time of publication of this guidance manual, EPA is continuing with Phases II and III to establish revised effluent limitations and standards for the remaining subparts. Over the next several years, EPA plans to complete these phases and will update 40 CFR Part 430 after the completion of each phase. The purpose of this guidance document is to help you, the permit writer, develop appropriate National Pollutant Discharge Elimination System (NPDES) permits and pretreatment requirements for mills with operations in Subparts B and E. The material presented is intended solely for guidance and does not alter any statutory requirements. For an overview of the NPDES and National Pretreatment Programs, you may refer to Section 2 of this document or to the U.S. EPA NPDES Permit Writer's Manual (EPA-833-B-96- 003) for more detailed information.