This document is the student workbook for a course in mathematics for water quality control personnel. This version contains complete problems, answers and references. Problems are arranged alphabetically by treatment process. Charts, graphs, and drawings represent data forms an operator might see in a plant containing information necessary for performing the calculations required. Treatment processes covered include: (1) an aerobic digestion; (2) effluent disposal; (3) grit removal; (4) primary sedimentation; (5) sand filtration; (6) sedimentation; and (7) trickling filter. (CS)