Environmental Study Released for Projects to Mitigate San Diego – Tijuana Transborder Water Pollution

Environmental Study Released for Projects to Mitigate San Diego - Tijuana Transborder Water Pollution

November 18, 2022

Today, the U.S. Environmental Protection Agency (EPA) and International Boundary and Water Commission, U.S. Section, (USIBWC) release the Final Programmatic Environmental Impact Statement (Final PEIS) for a set of proposed projects that comprise the Comprehensive Infrastructure Solution to mitigate transborder water pollution.

The Final PEIS, prepared in accordance with the National Environmental Policy Act, involves the planning, design, and construction of infrastructure to reduce transborder flows from Tijuana, Mexico, that carry treated and untreated wastewater, trash, and sediments into the U.S. These transborder flows impact public health and the environment and have been linked to beach closures in southern San Diego County, California.

"Achieving today's milestone affirms EPA and USIBWC's commitment to our border communities and our shared watershed, and it demonstrates tangible progress towards reducing transborder pollution," said EPA Pacific Southwest Regional Administrator Martha Guzman. "We look forward to continuing this critical work and hearing directly from communities across the watershed."

"Release of the Final PEIS is an important step as we work to implement a comprehensive solution to the border sanitation problems affecting public health and beaches in San Diego County," said USIBWC Commissioner Maria-Elena Giner.

EPA and USIBWC have identified the PEIS Alternative 2 (Core and Supplemental Projects) as the Preferred Alternative. This alternative includes:

• Expansion of the South Bay International Wastewater Treatment Plant capacity from 25 million gallons per day (MGD) to 60 MGD
• New infrastructure to divert additional flows from the Tijuana River
• Construction of a new advanced primary treatment plant in San Diego to treat up to 60 MGD of river flows
• One or more trash booms in the Tijuana River to capture solid waste
• Rehabilitation of sewer pipelines in Tijuana
• Construction of a new wastewater treatment plant in Mexico at San Antonio de los Buenos to address untreated wastewater discharges at that site that currently contaminate U.S. beaches, depending on the direction of marine currents
• Infrastructure for effluent reuse in Mexico

According to the Final PEIS, implementing Alternative 2 would reduce the number of days of transborder flow in the Tijuana River from an average of 153 to an estimated 36 per year - a 76% reduction. It would also eliminate raw sewage discharges into the Pacific Ocean at San Antonio de los Buenos, Mexico. Descriptions of all the alternatives, including descriptions of Core and Supplemental Projects, can be found in the Final PEIS and on the project website here.

EPA and USIBWC invite review and comment on the Final PEIS by the public and interested stakeholders. Comments on the Final PEIS can be submitted no later than December 19, 2022, to the following email address: [email protected]. EPA and USIBWC will issue a Record of Decision and announce its availability no sooner than 30 days after this notice of availability, and after considering public comments on the Final PEIS.