Trump EPA Tijuana Sewage Crisis Quarterly Update: Phase 2 of River Gates Under Construction, Parallel Gravity Line Completed, South Bay Plant Expansion Contract Awarded

Rehabilitation of four degraded sewage conveyance lines in Tijuana also advanced this quarter, and Mexico hosted a binational stormwater workshop in July that fulfilled a requirement of Minute 333, one of two historic agreements the United States and Mexico have reached to permanently end the decades-long crisis afflicting the San Diego region

"Once again, this latest public update highlights the urgent progress being made to fully implement last year's agreement," said EPA Administrator Lee Zeldin. "Safeguarding human health and the environment is EPA's foremost responsibility, and we are committed to ensuring that every American has access to clean air, land, and water." 

"The U.S. International Boundary and Water Commission (USIBWC), working closely with EPA, is accelerating design and construction of the South Bay International Wastewater Treatment Plant expansion while holding Mexico accountable for its commitments to address cross-border sewage flows," said USIBWC Commissioner Chad McIntosh. "Since President Trump took office, we have made significant progress on work that was previously moving too slowly. We are moving with the urgency this crisis demands to protect public health, restore access to San Diego's beaches, and end the foul odors affecting communities near the Tijuana River."

Actions taken by the Trump Administration are already delivering measurable results for Americans living in the San Diego region. Under President Trump's leadership:

• Treatment capacity along the border has more than doubled to 53 million gallons per day (MGD);

• The amount of effluent at canyon collectors has fallen 97%;

• South Bay International Wastewater Treatment Plant exceedances have fallen 99%; and

• Daily average dry season flows are down 54% in 2025-2026 compared to 2022-2024

See the full quarterly update below:

• South Bay International Wastewater Treatment Plant (SBIWTP) expansion to 35 MGD was completed August 2025.

• Parallel Gravity Line was completed August 2026.

• The U.S. Section of the International Boundary and Water Commission (USIBWC) is approaching the start of major construction on the treatment capacity expansion, to 50 MGD, of the SBIWTP:
  • Early work packages are underway to restore and maintain the current treatment plant and prepare for the expansion.
  • The first major construction phase for the expansion of the primary treatment works has been negotiated within budget and was awarded in September 2026. Construction is expected to begin soon after.
  • The full design of the expansion is nearing completion and is on track for approval in October 2026.
• Coordinating wet-weather readiness for El Niño winter: EPA and USIBWC have begun coordinating with regional agencies in San Diego and Tijuana to assess infrastructure integrity, including the Rodríguez Reservoir, in preparation for a potentially strong El Niño winter expected to bring heavy rain and a heightened risk of flooding from October through April.
  
• Channel clearing ahead of wet-weather season: As of late September, USIBWC had completed approximately 16,622 feet of maintenance work on both sides of the Tijuana River pilot channel, including vegetation removal, mowing, erosion repair, and embankment reshaping.
  
• Effluent relocation of La Morita and Arturo Herrera Wastewater Treatment Plants (WWTPs): This project diverts 10 MGD of treated effluent away from the Tijuana River to the Rodriguez reservoir for recharge. Construction began in February 2026 and is on track for completion by December 2027.
  
• Pump Station 1 (PB-1): This project eliminates potentially catastrophic discharges due to unreliable pumping capacity. Construction began in April 2026 and is on track for completion by November 2027. Construction was re-sequenced in favor of urgent repairs to the Antiguo Force Main, though PB-1 will still be certified by North American Development Bank (NADBank) by December 2026.
  
• Antiguo Force Main: Urgent repairs to this 2027 project have begun. Once complete next year, the full replacement of this 14,000-ft pipe will directly reduce the risk of untreated wastewater discharges to canyons on the US side and convey those flows for treatment at the San Antonio de los Buenos Wastewater Treatment Plant (SABWTP).
  
• Tijuana River Gates: This project reduces an estimated 5 MGD of flows from entering the Tijuana River. Phase 1 is fully funded by Mexico with 8 of 11 segments completed to date. Phase 2, funded by EPA's Border Water Infrastructure Program (BWIP), began construction in September 2026 to advance simultaneously with Phase I, and is on track for completion in early 2027.
  
• Pump Stations Matadero and Laureles II: Mexico has obligated funds for this project and construction is expected to begin in December 2026. These pump stations are in two different binational canyons and once rehabilitated, will help keep flows out of the U.S. and direct them to WWTPs in Tijuana.
  
• The following conveyance lines are being rehabilitated due to significant degradation, and once completed, will prevent potential sewage discharges into the Tijuana River from line ruptures:
  • Poniente Interceptor rehabilitation: 460 of 705 meters have been constructed with expected completion in December 2026
  • Oriente Interceptor rehabilitation: 421 of 1,600 meters have been constructed with expected completion in December 2026
  • Carranza Collector rehabilitation: 986 of 1,100 meters have been constructed with expected completion in December 2026
  • Insurgentes Collector rehabilitation: 205 of 5,431 meters constructed with expected completion in July 2027