Unique Opportunities for Effluent Reuse with Decentralized Treatment

Decentralized wastewater treatment is frequently used worldwide in those locations where additional water supply and shortages of potable water make reuse of highly treated wastewater more acceptable. Treated wastewaters often are less costly than development of other potable water supplies.The use of decentralized treatment facilities, which are commonly referred to as ‘scalping’ or ‘sewer mining’ facilities, typically produce a high quality level of wastewater effluent. Irrigation usage is often accomplished with only secondary levels of treatment followed by filtration and high levels of disinfection. Other indirect and direct potable water schemes require very extensive process configurations, including ultra filtration, reverse osmosis, and advanced oxidation.This paper will discuss several of the drivers for decentralized wastewater treatment, such as irrigation, water supply augmentation, stream flow augmentation, and industrial reuse. Several case histories of various wastewater treatment plants around the world will be presented, including design criteria, effluent standards, and other descriptive information.