In San José, AyA (the national water and wastewater government agency) owns and operates the Tres Rios Water Purification Plant and the Los Tajos Wastewater Treatment Plant. This 68 MGD, $45 million plant is one of the only wastewater treatment plants in the country. It was constructed in 2015 and includes first-class technology like CHP (combined heat and power), extensive odor control, centrifuge-based dewatering, and full SCADA control. With secondary treatment, it would rival top-notch plants in the United States.
In 2018, GWS organized its first wastewater workshop, tailored to educating AyA professionals, which took place at Tres Rios.