Mexicali, Baja California, Mexico

Wastewater Collection and Treatment Project (Mexicali IV) in Mexicali, Baja California

Status: Completed


In December 2006, CESPM’s system consisted of 280,232 water connections, with water and sewer service coverage rates of 98.1% and 87.5%, respectively.

The proposed project is the third phase of CESPM’s Wastewater Collection and Treatment Capital Improvement Plan. The first two phases—known as the Mexicali Sanitation Program and the Mexicali II Wastewater System Improvements Project—consisted of works to expand and improve the wastewater collection and treatment systems and entered into operation during the months of September and October 2007, respectively.

The third phase will extend wastewater collection and treatment services to the eastern area of the city, which has been designated Mexicali IV. Residents in this area currently rely on latrines, cesspools and open ditches for wastewater disposal. In addition, this area of the city is expected to see significant growth in the next few years.


The purpose of the project is to expand the wastewater collection and treatment system to currently unserved areas in the eastern region of the city, and it consists of:

  • Construction of sewer lines in nine subdivisions;
  • Construction of six main collectors;
  • Construction of three force mains and pump stations; and
  • Expansion of the existing Las Arenitas Wastewater Treatment Plant to double treatment capacity from 880 to 1,760 liters per second (lps) or 40 million gallons a day (mgd).


Implementation of this project will provide first-time wastewater services to unserved areas of the city, thus reducing the potential for groundwater and surface water contamination as well as health risks associated with raw sewage flows. It will also enable CESPM to collect and treat current wastewater flows in compliance with state and federal regulations.

Project Financing

Total Project Cost US 27.84M
NADBank Funding US 18.95M - NADBank Loan
Other Funding Partners Comisión Estatal de Servicios Públicos de Mexicali (CESPM)