Pre-Project Conditions
Untreated wastewater (WW) discharges from Nogales, Sonora flowed into the State of Arizona through the Nogales Wash. In addition, the rapid demographic growth of Nogales, Sonora created an additional WW treatment demand well beyond the capacity allotted to Mexico in the Nogales International Wastewater Treatment Plant in Arizona (NIWTP). Minute 276 of the International Boundary and Water Commission (IBWC) established that up to 9.9 million gallons per day (MGD) or 434 liters per second (lps) of the WW collected by Nogales, Sonora could be conveyed by gravity to the NIWTP. Transboundary flows in 2010 increased to annual averages of 12.5 MGD (548 lps) and showed no sign of decline. This project is referred as Los Alisos.
Project Objective
Eliminate exposure to untreated WW by expanding the WW conveyance and treatment to un-served areas, contributing to the reduction of groundwater pollution and the risk of water-borne diseases.
Project Scope
The project consisted of the construction of a wastewater treatment plant (WWTP) in Los Alisos River basin with an initial capacity of 5 MGD (220 lps). The project also included the construction of a lift station, force main and gravity outfall.
