San Ysidro

The challenge

Long-term public-private partnership ensures safe and cost-effective operation of unique wastewater treatment plant to address sources of groundwater contamination in Southern California.
At the start of the operations, maintenance and management (O&M) contract in 1996, Veolia North America had to provide startup services for a new wastewater treatment plant and long-term O&M of the South Bay International Wastewater Treatment Plant (SBIWTP), a 25-MGD advanced primary treatment facility located on a 35-acre site just south of San Ysidro.

The project challenges are:

  • The plant is an integral part of a regional system that was developed to address a long-standing Tijuana/San Diego border sanitation problem.

  • Initial services included restoring wastewater plant performance and compliance and providing qualified staff.

  • Following hurricanes in 2005, the challenge was to rebuild damaged systems and facilities and restore wastewater services.

  • Other elements covered by Veolia include five interceptor-collection systems, two pump stations and industrial leachate management, various canyons, drains and gulches, an effluent distribution structure, the South Bay Land Outfall, a 12,300-foot-long, 144-inch reinforced concrete pipeline, an effluent conveyance tunnel and an ocean outfall used to convey treated wastewater to the Pacific Ocean.

The solution

Innovative solutions:

  • Work as partner with U.S. International Boundary and Water Commission (IBWC) to operate and maintain a treatment system that addresses a critical waste management need for Mexico, while at the same time protecting U.S. waterways and beaches from uncontrolled wastewater discharges

  • Overcome challenges to ensure the treatment plant operates in full compliance with plant's design criteria

  • Worked with IBWC during construction of the new secondary addition to the wastewater treatment plant site, saving money and preventing a delay in the contractor's work plan

  • Managed IBWC's capital budget of $2.21 million

  • Performed more than 80 improvement projects at the SBIWTP facility, including the repair and maintenance of existing equipment, replacing primary sludge pumps, belt filter press pumps, SCADA upgrades, pug mill screw upgrades, new VFDs for non-potable pumps a new security system

  • Actively searched for O&M and administrative staff with Spanish-language skills

  • Assisted with the startup of the new wastewater plant and transition to secondary treatment, then assumed full operational responsibility for the new systems

  • ​Implemented a primary effluent filtration pilot program using Veolia testing equipment

Benefits for our clients


  • Contract renewed multiple times since 1996

  • Reduced chemical costs by more than $140,000 annually through improved process controls and plant modifications

  • Developed cost-effective solutions to engineering and operational problems that saved the client $100,000 in process modifications and repairs

  • Reduced laboratory costs through subcontracting some of the required analyses and by changing frequency and grouping of the constituents

  • Rebated approximately $750,000 in unspent chemical costs to IBWC when anticipated treatment trains were not brought on-line when expected

  • ​Accurate and timely reporting to the IBWC and all federal, state and regional regulatory agencies