San Diego

A “defensive” sewage interceptor system--designed to send back to Mexico about 1.5 million gallons of raw sewage flowing from Tijuana into border canyons in San Diego every day--went into operation Monday.

The system, which cost about $300,000 and was paid for by the U.S. government, will capture sewage from three canyons and send it back through a pipeline into the Tijuana sewer system. From there, it will be pumped to a sewage treatment facility at Point Loma, under a longstanding agreement with the City of San Diego.

Nikki Clay, special projects director for San Diego County, called the new interceptor system a significant step toward the goal of eliminating renegade sewage flows from Mexico, which contaminate the Tijuana River and, on occasion, stretches of beaches in Imperial Beach and Coronado, as sewage from the river’s mouth is carried north by ocean currents.

But even with the new system, major problems remain. Two canyons that also carry Tijuana sewage aren’t connected to the new system, although the City of San Diego also has plans to pump back those flows.

Progess is being made on other fronts, however. Sometime in the spring, Mexican officials hope to have in operation a series of settling lagoons where sewage flows can be diverted. In addition, the Mexican government is building a sewage treatment plant south of Tijuana, the first stage of which is scheduled for completion next year.

The sewage seeping into the canyons comes from homes not linked to Tijuana sewer lines. It is estimated that as much as 20 million gallons a day of this renegade sewage flows into storm drains and the Tijuana River.