This research addresses the public health importance of waterborne disease prevention and the effectiveness of prevention strategies in non-outbreak settings. Because of the popularity of recreational water activities and the concern for the health of swimmers, this research promotes knowledge and skills related to preventing the spread of waterborne disease. The study design was a behavioral intervention to test the effectiveness of a waterborne disease prevention training session. The primary outcome of this study was to advance aquatic staff in stages of behavior change and knowledge in regard to waterborne disease prevention. Outcome measures were assessed by comparison of pre and posttest survey results. A training manual was designed for this intervention and edited by the Centers for Disease Control and Prevention. Data collection instruments included three questionnaires: a behavior survey to measure stages of change, a waterborne disease knowledge survey and a demographics survey. An evaluation form was administered after the training session. The stages of change behavior survey assessed each participant’s stage in regard to behaviors related to waterborne disease prevention. There are five emphasis areas in the behavior survey to assess the implementation or existence of recreational water illnesses (RWI) prevention: 1) facility maintenance, 2) pool chemicals and water quality, 3) pool policies, 4) diaper policies and 5) recreational water illness training. The knowledge survey consisted of ten multiple-choice questions about waterborne diseases and how to prevent them in chemically treated swimming water. Demographics data were controlled in the analysis. The five behavioral emphasis areas and knowledge were the dependent variables for analysis. The participants who received the training advanced to another stage or progressed within a stage in all five behavioral emphasis areas. These participants also gained 35 percent in knowledge from pre to posttest. The control participants did not advance in stages of change or increase in knowledge. The data were analyzed using a general linear model approach. Interactions of group and pretest scores were the strongest predictors of the posttests scores (p < .05). This intervention has proven to be a useful tool for training aquatic staff in preventing waterborne disease in chemically treated swimming water.