This manual serves as a guide for the preparation of a Quality Control Handbook for processes related to water and wastewater treatment. A Quality Control Handbook describes activities and procedures necessary to ensure provision of quality products and services by a water utility. Proper documentation of the processes for water and wastewater treatment allows concerned employees to appropriately address, repair, and report to management any operational defects or deviations from standard operating procedures. Such a handbook also helps supervisors and managers to monitor the implementation of required procedures and offers information on the proper way of handling defects and deviations, once they occur. Moreover, the handbook serves as a document for resolving policy disputes on quality issues, as well as a platform for discussing ways to further improve operational efficiency and product/service quality.