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South Bay International Wastewater Treatment Plant (SBIWTP)

The SBIWTP is a 25 million gallon per day secondary treatment plant located in San Diego County, California, about 2 miles west of the San Ysidro Port of Entry. The plant treats sewage originating in Tijuana, Mexico and discharges it to the Pacific Ocean through the South Bay Ocean Outfall, a four and one-half mile long 11foot diameter pipe completed in January 1999. From here you can link to various informative pages about the SBIWTP located in San Ysidro, CA.

The South Bay International Wastewater Treatment Plant (SBIWTP) was designed to deal with the growing demand for the treatment of wastewater resulting in the contamination of the Tijuana River in the United States. It has been an ongoing concern since 1934 when the International Boundary Commission (IBC) was instructed by the United States and Mexican governments to cooperate in the preparation of a report on the Tijuana sewage problem. The SBIWTP is capable of providing secondary treatment for 25 million gallons per day (mgd) average daily flows of sewage in excess of the Tijuana sewage system capacity, but has expansion capability of up to 100 mgd. The SBIWTP was built on a 75-acre site near the international boundary in the U.S. immediately north of Tijuana's main wastewater pumping station. Resulting from the establishment of a binational interagency "Clean Water Partnership," the United States and Mexico approved IBWC Minute No. 283 dated July 8, 1990. This Minute authorized the construction of the SBIWTP. The Government of Mexico contributed $16.8 million toward construction of the SBIWTP and currently contributes $2.0 million toward the annual operation and maintenance costs.  Funding for the U.S. share of construction costs was appropriated through the Environmental Protection Agency in the amount of $239.4 million.  Of that amount, $225.5 million had been obligated as of 2002, of which $89.2 million was given to the City of San Diego and the Corps of Engineers to construct the South Bay Ocean Outfall; $8 million was given to the Corps of Engineers for environmental work; and $127.4 million was given to the USIBWC for the costs associated with the construction of the SBIWTP and related infrastructure. Mexico's share is that amount that Mexico would have had to pay to construct and maintain a plant at the Rio Alamar. At the same time, Mexico is expanding its sewage collection system, and constructing additional works necessary to collect and convey Tijuana's sewage. These facilities will be operated and maintained at Mexico's expense. Both countries share in the operation and maintenance of the SBIWTP.

Operations & Maintenance
View the O&M page that gives information about all O&M projects of the U.S. IBWC. 

Official SBITWP Brochure
Visit the SBIWTP official brochure for more information.

SBIWTP Background
View background information about how the SBIWTP solution came about.

SBIWTP & Ocean Monitoring Water Quality Data
View data relating to discharges and quality of wastewaters generated in the City of Tijuana and treated at the SBIWTP as well as various ocean water quality monitoring stations.