Designed for individuals who have completed National Pollutant Discharge Elimination System (NPDES) level 1 laboratory training skills, this module on digestor gas analysis provides waste water treatment plant operators with the basic skills and information needed to: (1) successfully run the carbon dioxide analysis test; (2) accurately record data and observations; (3) organize data to perform required calculations for the test; (4) make general interpretations as to the quality of digestor gas utilized in the test; and (5) obtain reliable, consistent results from the test procedure. The instructor's manual contains a statement of instructional goals, lists of instructor/student activities and instructional materials, and student worksheet (with answers). The student workbook contains objectives, prerequisite skills needed before the module is started, sources of Fyrite Carbon Dioxide Analyzers, laboratory procedures (monitoring changes in digestor activity by determining carbon dioxide with a carbon dioxide analyzer), and worksheet. (Author/JN)