Costs and Benefits of Using Wastewater for Aquifer Recharge

While direct use of wastewater in treated, partially treated, untreated, and diluted forms has been in practice in irrigation systems for a long time, planned use of wastewater for aquifer recharge has been practiced over the last few decades only. We address tradeoffs of using wastewater for aquifer recharge and present the case studies on (1) recharge of groundwater in the Mezquital Valley, Mexico to provide a source of water supply for irrigation and other uses; (2) recharge of depleting Ezousa and Akrotiri aquifers in Cyprus to support irrigation of a range of crops and landscape; (3) supply of wastewater to Amani Doddakere Lake close to Bangalore in India for groundwater recharge, later to be used in irrigation; (4) injection of wastewater into the Bolivar aquifer in Australia in winter for recovery in summer when peak horticultural demands exceed supply; and (5) revitalization of the over-exploited Mashhad Plain aquifer in Iran to reduce contamination and improve water quality for irrigation. While valuation of treated wastewater use for aquifer recharge reveals favorable environmental and economic benefits, public acceptance of indirect use is not yet universal. Moreover, related legal frameworks and supportive policies and institutions are lacking in many countries. These aspects need to be addressed to implement and promote planned use of wastewater for aquifer recharge for multiple benefits.