Decentralized wastewater management: challenges and opportunities for the twenty-first century

Decentralized wastewater management (DWM) may be defined as the collection, treatment, and reuse of wastewater from individual homes, clusters of homes, subdivisions, and isolated commercial facilities at or near the point of waste generation. In some areas, the liquid portion could be transported to a central point for further treatment and reuse. At the time of writing (2002), more than sixty million people in the United States live in homes where individual decentralized systems are used for wastewater management. Further, the U.S. EPA now estimates that about 40 percent of the new homes being built are served with onsite systems. In the early 1970s, with the passage of the Clean Water Act, it was often stated that it was only a matter of time before sewerage facilities would be available to almost all residents of the continental United States. Now, more than 25 years later, it is recognized that complete sewerage of the entire U.S. may never be possible, due to both geographic and economic constraints. Because complete sewerage is unlikely in the foreseeable future, it is clear that DWM systems are needed for the protection of public health and the environment and for the development of long-term strategies for the management of our water resources. The challenges and opportunities for DWM systems in the twenty-first century are discussed in this paper.