The ultimate aim of these Guidelines is to protect and promote public health. Adequate capacity is required at the national level to maximize the benefits of the use of wastewater, excreta and greywater in agriculture and aquaculture, to minimize the health risks involved and to promote proper environmental management, ensuring long-term sustainability. An essential element of this national capacity consists of an enabling policy environment. This chapter summarizes the information needed to formulate decision-making criteria, establish decision-making procedures and create effective institutional arrangements for their implementation.