Depending on the region and the geology, untreated water may contain, naturally occurring toxic elements, such as arsenic (As), uranium (U) and fluoride (F). These elements, which are considered as extremely poisonous, are directly transmitted to people when the untreated water is used for drinking, food preparation, recreation, or for various domestic purposes (Bhatnagar et al., 2011; Iakovleva and Sillanpää, 2013; Nordstrom, 2002). As a result millions of people around the world are threatened by F, As and U contamination. There is, thus, a need for low-cost and proven technologies that can effectively treat polluted water especially in developing countries. In this chapter, novel and conventional techniques are critically reviewed for the removal of these toxic contaminants from groundwater and wastewater.