In this seminar, we introduce “Bellefomer®,” a biological sludge volume reduction agent that can reduce excess sludge by up to 100%. Excess sludge generated during wastewater treatment requires processes such as dewatering and incineration, resulting in treatment costs and environmental impact. Bellefomer® combines a microbial agent containing microorganisms that decompose activated sludge with technical support. An optimal microbial consortium is customized to each facility’s activated sludge, with operational strategies proposed based on microscopic observations and operational data to maximize sludge reduction. Actual cases have achieved zero excess sludge removal while maintaining treated water quality, reducing treatment costs and CO₂ emissions. The seminar covers the mechanisms of sludge volume reduction, ways to maximize its effectiveness, and specific implementation cases, highlighting its potential to reduce maintenance costs and environmental impact.