Wastewater reclamation, recycling and reuse: past, present, and future

The scientific basis for the current status of wastewater reclamation, recycling and reuse has evolved from developments in water and wastewater engineering coupled with increasing pressures on water resources. Milestone events that have led to the safe use of reclaimed wastewater are reviewed. The role of engineered systems associated with reclaimed wastewater is discussed in the context of the natural hydrologic cycle. A synopsis of the significant studies that form the basis for current regulatory approaches and technological innovations is presented. Current water reclamation strategies incorporate multiple measures to minimize health and environmental risks associated with various reuse application. A combination of source control, advanced treatment process flowschemes, and other engineering controls provides a sound basis for increased implementation of water reuse applications. The feasibility of producing reclaimed water of a specified quality to fulfill multiple water use objectives is now a reality due to the progressive evolution of technologies and risk assessment procedures. Future water reuse directions are charted.