Safe Management of Chemical Contaminants for Planned Potable Water Recycling

Planned potable water recycling has become an important strategy for managing drinking water supplies in a growing number of countries including Australia, the USA, Namibia, Singapore and some parts of Europe. This involves the advanced treatment of municipal wastewaters (treated sewage) prior to reuse by supplementation of drinking water supplies. In order to ensure the protection of public health, careful assessment and management of trace chemical contaminants is essential. Important chemical contaminants include pharmaceuticals, personal care products, steroidal hormones, pesticides, industrial chemicals, perfluorochemicals, antiseptics and disinfection by-products. Monitoring of key toxic chemicals of concern is important and can be supplemented by techniques for direct toxicological assessment of whole water samples. Furthermore, monitoring of a limited range of identified indicator chemicals and surrogate parameters can be an effective means for confirming ongoing treatment performance of individual unit treatment processes. This chapter provides a description of some of the most significant planned potable water recycling schemes currently in operation or under development around the world. It highlights the various approaches used in the assessment of chemical safety for these schemes, and hence the alternatives that are available for the assessment of future potable water recycling schemes.