Mexicali, Baja California, Mexico

Sanitation Program of the City of Mexicali - Mexicali,Baja California

Status: Completed


Wastewater (WW) discharges from the sewage system of the city of Mexicali had deteriorated the water quality of the New River. Mexican and US Governments coordinated actions within the framework of the International Boundary and Water Commission (IBWC) agreements reached in minutes 264 and 294, to create a Sanitation Program to solve this problem. These minutes included an integral sanitation program for Mexicali, consolidation of planning studies and specified quality conditions for treated municipal water to be discharged to the New River. This Project was referred as Mexicali I Project.


The purpose of the Project was to eliminate exposure to untreated wastewater discharges by expanding the wastewater collection system to unserved areas, reducing groundwater pollution and the risk of waterborne diseases.


The extended scope consisted of 19 projects to improve WWC and WWT to over 46 colonias, including new and rehabilitated collectors; building pumps stations 4 and 8; and rehabilitating and expanding the Zaragoza WWTP to a capacity of 29.7 MGD.

Project Financing

Total Project Cost US 54.98M
NADB Funding US 20.62M - NADB Grant: BEIF

Project Photos

Results Measurement

Results are measured upon completion of the project through a closeout process that assesses project performance within 6-12 months after completion, as well as the achievement of the goals and objectives established at the time of project certification and financing approval.



Increase and Improve access to wastewater treatment services

Reduction of untreated wastewater discharges to water bodies



Increased/Improved wastewater treatment

29.7 MGD

Compliance to applicable laws and regulations


Quantity of uncollected wastewater discharges eliminated

7.3 MGD



Increase/Upgrade capacity of Zaragoza WWTP

29.7 MGD

Pump Stations 4 and 8


Wastewater connections


Construction of the Choropo WWTP

Not Completed

New and rehabilitated WWC system 8" to 48" diameters (miles)


Significant Project Finding(s)

The construction of El Choropo WWTP was cancelled due to Farmers opposition. It needed to be relocated and recertified with the subsequent Mexicali II project. The upgrade and rehabilitation addressed operational and odor issues at the Zaragoza WWTP.