This research program was conducted with two objectives: (1) evaluation of waterborne radon impacts on indoor air quality, and (2) assessment of available control technologies to limit indoor exposures to radon and its decay products. This report contains a review of radon's physical, chemical and radiological properties; a summary of its decay chain; and a synopsis of health risks, existing regulations, and recommendations concerning exposure to radon and progeny. This report also presents assessments of reported techniques for removal of radon from water or indoor air. Techniques evaluated for removal of radon from water include decay, aeration and granular activated carbon. Techniques evaluated for removal of radon and/or progeny from air include circulation, various types of ventilation, filtration, electrostatic precipitation, charcoal adsorption, chemical reaction, and space charging. Where the reports examined include a sufficient amount of information to do so, an evaluation of the cost, efficiency and practicality of each technique is provided.