[3] Mexico and the United States spent $91 million upgrading Mexicali's sewers in recent decades, but funding has dropped in the 2010s.

[3] Las Arenitas wastewater plant opened in 2007 south of Mexicali, greatly improving water quality, particularly bacteria levels.

However the overburdened sewer system began periodically dumping raw sewage into the river, resulting in spikes in bacterial levels.

[3] In 2016 the Mexicali Public Service Commission took over regulation of wastewater discharge from the Environmental Protection Department of the state of Baja California, increasing oversight.

These boroughs offer administrative services such as urban planning, civil registry, inspection, verification, public works and community development and are served by a delegado.