During the summer of 1980, a comprehensive study of Arizona’s Water System Operator Certification Program was conducted. A manual containing the results of the study was prepared by Brown and Caldwell Consulting Engineers for the Arizona Department of Health Services under a grant from the United States Environmental Protection Agency. The primary purpose of the study was to develop guidelines for preparing certification examinations which reflect the actual tasks and duties of operators in the field. Although the present operator certification regulations call for separate certification of water distribution operators by July 1, 1982, it currently appears that the Bureau of Water Quality Control will be unable to implement the distribution system certification program by July 1, 1981, as planned. Regulation revisions are now being considered which would postpone the certification requirement dates for distribution operators by 18 months.