How do we dispose of human wastes, both urine and feces, such that our actions lead to a sanitary environment that promotes good health for people? In this chapter we deal primarily with the sanitary disposal of human waste. We also want to use feces and urine for a beneficial purpose, the production of a useful byproduct of this process—fertilizer. In some societies “night soil” (raw untreated sewage) is used to fertilize fields. Plants use the nourishment and are very productive, but, as we mentioned in Chapter Two, untreated feces encourage pathogens that infect farmers, causing serious health effects and the crops become infected causing additional health issues. These serious effects stem mainly from using untreated sewage and eating plants contaminated with pathogens.