In 2020 the U.S. government through the Environmental Protection Agency (EPA) committed $300 million in The United States Mexico Canada Agreement (USMCA) trade agreement to identify infrastructure solutions to mitigate the transboundary pollution. Infrastructure solutions for transboundary flows from the Tijuana River have been studied for the past year. The Environmental Protection Agency, which has been tasked with creating solutions, originally proposed 10 possible projects. In time the projects have been narrowed down to three, which were presented during the last virtual public information meeting on Aug. 6.
The three projects have been identified as I, H, and E-2.
Project I is the most expensive and above budget at a cost of $566 million. It is referred to as Comprehensive Alternative. The projected percentage of reduction in days of transboundary flow annually in the Tijuana river is 76% and a reduction in days with impacted water quality in Imperial Beach (in summer) is 95%. Annual operations and maintenance expense is estimated at $22 million. The total amount treated is expected at 60 million gallon per day (MGD). This project combines the following solutions: U.S. River Diversion and Treatment, Mexican River Diversion and U.S. Treatment, U.S. International Treatment Plant (ITP) Expansion Treatment, Canyon Treatment at ITP, Mexico Collection Improvements, Tijuana River Trash Boom, Reuse of Treated Water in Mexico, and a New Treatment Plant at San Antonio de Los Buenos. The benefits of this project include an increased capacity at the ITP and improvements in water quality in Imperial Beach, for Border Patrol agents as well as a reduction in reliance on infrastructure Mexico.
Alternative H is referred to as Wastewater Treatment Alternative. This project would reduce transboundary flows in the Tijuana River by 54% with a 74% reduction in days with bad water quality. This projects falls within the budget at $336 million, with an annual operations and maintenance of $2 million. This alternative includes most of the solutions of Alternative H except for: U.S. River Diversion and Treatment, Mexico River Diversion and U.S. Treatment and New Plant at San Antonio de Los Buenos. This alternative can treat up to 50 MGD that would be discharged through the South Bay Ocean Outfall.
Alternative E-2 called the Hybrid Alternative also encompasses the other two projects solutions except for the canyon treatment at ITP and the new plant at San Antonio de Los Buenos. E-2 would reduce 64% or transboundary flow and 63% of impact at the Imperial Beach shoreline. Its estimated cost is $344 million with $14 million in operations and maintenance. E-2 can treat 75 MGD discharged through the South Bay Ocean Outfall. Benefits of this project include taking care of river water and sewage from Central Tijuana and the capture of flow when Mexican infrastructure fails. This alternative still impacts the Border Patrol and the coast with the least reduction of pollution.
Attendees of the meeting had the opportunity to ask questions in the chat feature. Assistant Water Director for EPA Southwest Region 9 Dave Smith responded to some of the questions and said a final decision has not been reached, as to which alternative will be chosen. There is an ongoing discussion with partners in Mexico to see which project they are interested in building with a private/public partnership.
“This enables us to finance projects differently and get more mileage of resources. We’re open to consider a private/public partnership,” said Smith. “Another possibility is funding from the state of California and leverage federal with state funds to address the issues…trying to get as much pollution flow as we can, so that the water gets treated before it reaches discharge points… that will help in reducing pollutants discharge.”
Smith pointed out an issue of concern - sediment. “We chose projects that are not focused on sediment, it is a significant issue, but we had to prioritize,” he said.
Tom Konner, environmental engineer at EPA Region 9, gave an overview of near and long term milestones. In the near term the National Environmental Policy Act Environmental Impact Study will begin as are negotiation with Mexico.
In the long term an agreement with Mexico will be reached, and a project sponsor will be identified, most likely International Boundary & Water Commission (IBWC.) IBWC cannot currently take funds or start a project until legislation is changed. It was announced that there is legislation going through Congress right now to make IBWC take a lead role in the design and construction of the projects. In addition, operations and maintenance funds for long term operations will have to be identified.
Salvador Lopez of the North American Development Bank gave an overview of the projects and rehabilitation of infrastructure that have been completed in Mexico. Some of the more important ones are the Collector Poniente and the rehabilitation of Collector Oriente. Four more collectors are slated for repair or replacement to eliminate wastewater discharges or risk of discharges.
To view the slides shown during this meeting log on https://www.epa.gov/sustainable-water-infrastructure/tijuana-river-watershed-stakeholder-engagement.