Over the past two decades water demand has increased dramatically all over the world and scientists are focusing on finding alternative sources for water. Centralized treatment systems are uneconomical and inefficient in treating wastewater to reusable levels. Some studies hold that large centralized treatment systems are not a sustainable option for developing countries such as India, China, and South Africa. In India, systems that require more electricity fail to perform satisfactorily, as the power supply is intermittent and finds for operation and maintenance are not secure. Therefore, treating wastewater near its generation point and reusing it is a better solution. Policy makers are focusing on building decentralized treatment facilities in rural and peri-urban areas, with very few being built in urban area. Decentralized approaches aim not only at treating wastewater but also at providing benefits such as reusable water, energy efficiency, and nutrient recovery and reuse. However, the selection of technologies/management strategies depends upon the economic well-being of the community, the efficiency of the technology, social acceptance, and other factors. A matrix for decision-making in choosing the best technological option is essential and is included in this chapter. The two better-performing decentralized wastewater treatment systems for rural and urban India is also discussed in this chapter, along with the option chosen for reusing wastewater in an Indian textile manufacturing area.