Conductng simple analyses, routinely and consistenty, is key to understanding the microbiological working of the wastewater treatment plant. In other words doing the same thing ( no matter how simple or how complicated), the same way on a regular basis, can be valuable tool for the most sophisticated treatment system to the most simple It is my goal that this book can be used as a practical guide and reference to assist you in developing simple procedures for incorporating microbiological observations into your everyday process control program.