Of special interest to wastewater treatment plant operators are the bacteria that degrade nitrogenous wastes–the nitrifying bacteria–and the bacteria that degrade carbonaceous wastes–the cBOD-removing bacteria. Both groups of bacteria need to be routinely monitored and operational conditions favorably adjusted to ensure desired nitrification. Each chapter in this groundbreaking study offers a better understanding of the importance of nitrification and denitrification and the bacteria involved in these crucial processes. Chapters include: