Wastewater contains a wide range of hazardous and non-hazardous constituents. If not properly treated, wastewater discharge or reuse can cause serious public health outcomes, such as outbreaks of infectious diseases and acute and chronic toxicity events. This chapter first describes an overview of the health effects associated with potentially hazardous wastewater constituents including microbial pathogens and toxic chemicals, and their impacts in different wastewater management scenarios, including discharge, agricultural reuse, non-potable reuse, and indirect and direct potable reuse. Naturally, different wastewater management scenarios represent different types of hazards to different groups of populations. For example, wastewater irrigation affects farmers and their families, surrounding communities, and consumers, while urban non-potable reuse, such as recreational impoundments, can pose a health risk on facility users through direct contact and accidental ingestion. The second part of this chapter focuses on the impact of wastewater treatment on hazard reduction. Various conventional, advanced, and low-rate treatment systems are covered, and conceptual treatment schemes for achieving various effluent/reclaimed water qualities suitable for safe discharge and reuse are presented. In order to encourage more aggressive water reuse scenarios such as direct potable reuse, more research is needed in the area of trace organic contaminants, with respect to their potential public health effects, monitoring, and control.