Along the Arizona-Sonora border, the same wastewater that was once considered only a threat to public health is now seen as a valuable commodity. In the present period, growing populations, more demand for fixed supplies of water and extended drought have made people realize effluent’s true value. Wastewater is now seen as a key component of water budgets that can be treated and utilized for non-potable uses.
The cities of Ambos Nogales share surface and groundwater resources. Wastewater generated in Nogales, Sonora and Nogales, Arizona (Ambos Nogales), is jointly treated at the Nogales Wastewater Treatment Plant (NIWTP) in Rio Rico, Arizona. Seventy percent of the wastewater treated by the plant is generated in Nogales, Sonora. This paper considers some of the issues related to the management of Mexican effluent in Ambos Nogales. It describes possible mechanisms for management and how new developments may present opportunities for new ways to manage effluent between Mexico and the United States. These new developments include a proposed electrical generating plant which could utilize the effluent for cooling, a new water management authority in southern Arizona, and a scenario to cycle a portion of the effluent back to Mexico.