activity-dine activity-more activity-play activity-shop activity-stay arrow-leftarrow-rightArtchevron-downchevron-rightchevron-up close download email gridlistlocationmime-default mime-link mime-pdf mime-video Parkspin search social-facebook social-flickr social-instagram social-linkedin social-pinterest social-rss social-twitter social-youtube berth-request-form blue-economy boat-launches breakbulk contact-the-port cruise-information current-rfps dine docks-and-anchorages drybulk economic-impact events faqs green-business-network harbor-police job-opportunities live-vessel-tracking news play port-events public-meetings refrigerated-avocados refrigerated-bananas refrigerated-pineapple shop stay tenant-resources tidelands-activation-program view-bidding-opportunities commercial-vessels current-conditions directions fact security agendas calendar cruise documents information jobs map meeting minutes notification parking permits reporting reports reservation rfps rules tap vendors video-play weather-cloudy weather-partly-cloudy weather-rainy weather-sunny weather zoom Skip to main content
General Press Releases

Transboundary Sewage Case Closed, Interim Mitigation Measures Being Implemented, Comprehensive Infrastructure Solution Getting Started

Media Contacts: Port of San Diego - Brianne Mundy Page, 619.348.1518; City of Imperial Beach - 619.432.8303; City of Chula Vista - Anne Steinberger, 619.405.6461

The Cities of Imperial Beach and Chula Vista and the Port of San Diego’s litigation against the United States Section of the International Boundary and Water Commission (USIBWC) for failing to prevent transboundary sewage flows into the Tijuana River Valley came to a close yesterday with final resolution of Plaintiffs’ claims for attorneys’ fees and costs.

“Our region and especially the people of Imperial Beach have suffered for decades the impacts of sewage pollution to our beaches. Our lawsuit was the key that finally unlocked all of the action we are now beginning to see, actions that will help protect public health, our economy, and our environment,” said Imperial Beach Mayor Paloma Aguirre. “There is a lot of work ahead of us still, but our regional partnership is stronger than ever, and we are committed to working collaboratively with the federal government to solve, once and for all, one of the worst water pollution crises in America.”

“The City of Chula Vista pledged our support for this lawsuit to ask federal officials to address the flow of sewage onto our South County waters and beaches,” said Chula Vista Mayor John McCann. “We are glad the EPA is working with stakeholders toward a resolution of these issues and that interim mitigation and monitoring measures are underway.”

“This victory is for the environment, the residents of Imperial Beach and South County, and anyone who wants to spend a day at the beach without fear for their health. But, make no mistake, until the federal government and Mexico complete their long overdue sewage infrastructure projects, polluted waters will continue to flow through the Tijuana River Valley and into the ocean waters off Imperial Beach every time it rains,” said Commissioner Dan Malcolm, Imperial Beach’s appointee to the Port of San Diego Board of Port Commissioners. “We remain steadfast in our dedication to the health and safety of our communities and will continue with our partners to engage with the EPA and USIBWC to expedite their projects. Time is of the essence to end this decades-long public health and environmental crisis.”

As part of the historic April 2022 settlement, Plaintiffs dismissed their Clean Water Act and Resources Conservation and Recovery Act claims against USIBWC. Pursuant to that settlement, USIBWC is implementing several substantive measures to mitigate the effects of transboundary pollution in the Tijuana River Valley and to improve situational awareness and the flow of information from USIBWC to stakeholders. The actions include:

  • Installation and maintenance of the temporary sediment berm to detain dry weather transboundary flows through the USIBWC flood control channel, as well as prompt reconstruction of the berm after washouts;
  • Improved daily inspection and cleaning of canyon collectors and establishment of a communications protocol with the Comisión Estatal de Servicios Públicos de Tijuana and Customs and Border Protection to address trash buildup at canyon collector intakes;
  • Installation of water quality monitoring catch basins at each of the canyon collectors;
  • Preparation and implementation of a plan for spill and transboundary flow response actions at Stewart’s Drain, a particularly problematic canyon collector; and
  • Publication of transboundary flow events via Twitter to improve public awareness.

These actions reflect interim mitigation measures while the U.S. Environmental Protection Agency (EPA) proceeds with spending $300 million in funding as part of the United States-Mexico-Canada Agreement Implementation Act (USMCA), which were allocated during the course of this litigation to design, construct, and operate the Comprehensive Infrastructure Solution to address chronic transboundary flows.

The Final Programmatic Environmental Impact Statement for projects funded by the USMCA was released in December, and a final Record of Decision (ROD) is estimated early in 2023. The expansion of the South Bay International Treatment Plant (SBIWTP) is a core component of the Comprehensive Infrastructure Solution and is vital to efforts to successfully address transboundary sewage flows. Design and construction of the SBIWTP expansion will begin soon after the ROD is completed.

The City of Chula Vista is the second-largest city in San Diego County with a population of 277,220. Chula Vista boasts more than 50 square miles of coastal landscape, rolling hills, quality parks, and miles of trails. The City is a leader in conservation and renewable energy, has outstanding public schools, and has been named one of the top safest cities in the country. Established neighborhoods, contemporary communities, start-up firms, corporations, a U.S. Olympic and Paralympic Training Site, and historic downtown contribute to Chula Vista’s attraction for both families and businesses. A promising future includes developing the 535-acre Chula Vista Bayfront, implementing smart city technology citywide, and planning for a new university on 375 acres. Find us on @thinkchulavista or

About THE Port of San Diego

The Port of San Diego serves the people of California as a specially created district, balancing multiple uses on 34 miles along San Diego Bay spanning five cities. Collecting no tax dollars, the Port manages a diverse portfolio to generate revenues that support vital public services and amenities.

The Port champions Maritime, Waterfront Development, Public Safety, Experiences and Environment, all focused on enriching the relationship people and businesses have with our dynamic waterfront. From cargo and cruise terminals to hotels and restaurants, from marinas to museums, from 22 public parks to countless events, the Port contributes to the region’s prosperity and remarkable way of life on a daily basis.


Port of San Diego Environment champions the safekeeping and environmental care of our diverse ecosystems. Year after year, environmental goals are set and measured to evolve environmental initiatives – ensuring San Diego Bay remains a vibrant resource and contributes to a remarkable way of life for visitors and residents for generations to come.