FIGURE 2-2 Estimated Contribution of wastewater effluent to overall river flow in the River Ouse (UK).
SOURCE: Andrew Johnson and Richard J. Williams, CEH, personal communication, 2009.
As an alternative to releasing wastewater effluent into the environment, reclaimed wastewater can be reused for a variety of purposes (Table 2-2). Currently, most reclaimed water is used for nonpotable applications, such as agricultural and landscape irrigation. (Data on the extent of various reuse applications in several states is presented toward the end of this chapter.) The following section discusses a variety of nonpotable reuse applications and associated technical and water quality considerations. Economics, the regulatory framework, and public acceptance also influence planning decisions about nonpotable reuse, and these factors are examined in Chapters 9 and 10.
Urban Reuse Applications
A wide array of uses for nonpotable reclaimed water have been identified in urban areas. Urban water reuse systems currently provide reclaimed water for landscape irrigation, decorative water features, toilet and urinal flushing, fire protection, cooling water for air conditioners, commercial uses (e.g., car washes, laundries), dust suppression, and street washing, among others. For example, in Florida, urban nonpotable applications (i.e., industrial uses, public access irrigation) represented at least 68 percent of total reclaimed water use by flow volume in 2010 (FDEP, 2011). Industrial and landscape irrigation reuse applications are discussed in more detail below, along with dual distribution systems that enable these applications.
Landscape irrigation is the most widely used application of reclaimed water in urban environments and typically involves the spray irrigation of golf courses, parks, cemeteries, school grounds, freeway medians, residential lawns, and similar areas. Because public contact with the applied water presents potential health