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DATE: |
January 28, 2026 |
15 |
SUBJECT
Title
RECEIVE UPDATE FROM THE AD HOC SUBCOMMITTEE ON TIJUANA RIVER SEWAGE CRISIS INCLUDING SATURN BOULEVARD INFRASTRUCTURE AND EPIDEMIOLOGICAL HEALTH STUDY (DISTRICTS: ALL)
Body
OVERVIEW
The Tijuana River Valley (TJRV) and surrounding South Bay communities continue to experience severe impacts from untreated sewage, urban runoff, and toxic airborne emissions, resulting in recurring contamination of coastal waters and nearby neighborhoods. These conditions continue to pose significant risks to public health, environmental resources, and economic activity across affected cities and unincorporated communities.
In response, the San Diego County Board of Supervisors (Board), has proclaimed a local emergency and in coordination with regional, State, and federal partners, has advanced a series of actions. Since the Board’s most recent update, efforts have focused on advancing studies and implementation planning intended to better quantify impacts and inform near- and long-term response strategies.
On September 30, 2025 (3), staff returned to the Board with updates on multiple actions, including air quality interventions, the County Pollution Crisis Chief position, planning for the epidemiological health study, and the Saturn Boulevard feasibility study. At that time, staff committed to continuing work through the Ad Hoc Subcommittee to refine implementation plans for priority initiatives, ensuring alignment with Board direction and community needs.
Building on prior Board actions including the adoption of a five-point response framework, under the leadership of the Ad Hoc Subcommittee on the Tijuana River Sewage Crisis, staff have made progress on a number of key initiatives as directed by the Board. These include identifying a path forward for an epidemiological public health impact study, initiation of an economic impact study to assess losses associated with the sewage crisis, and advancement of a feasibility study for infrastructure improvements at Saturn Boulevard to mitigate harmful emissions.
Since November 2025, the Ad Hoc Subcommittee on the Tijuana River Sewage Crisis has convened on a monthly basis to receive updates, discuss emerging issues, and provide guidance on the coordination and implementation of priority actions related to this ongoing environmental and public health crisis. Today’s item, presented by the Ad Hoc Subcommittee on the Tijuana River Sewage Crisis, provides an update on the epidemiological public health impact study and the feasibility study for infrastructure improvements at Saturn Boulevard, directs the Chief Administrative Officer to refer the items to the Unlocked Reserves Framework, and authorizes a competitive procurement for a long-term health study.
RECOMMENDATION(S)
SUPERVISOR TERRA LAWSON-REMER AND SUPERVISOR PALOMA AGUIRRE
1. Receive this update on ongoing efforts to strengthen the County’s response to the Tijuana River sewage crisis including long-term epidemiological study, retrospective health study, and the infrastructure project at the Saturn Boulevard hotspot.
2. Direct the Chief Administrative Officer to include the following items within the Unlocked Reserves Framework:
a. $2.0 million for the long-term health study, contingent on the remaining funds in the amount of $4.0 million being contributed from other funders;
b. $250,000 for a retrospective health study; and
c. $2.5 million for the capital costs to construct a temporary pipe extension at Saturn Boulevard. Should alternative funding be identified, the $2.5 million will support immediate needs for the Tijuana River Valley.
3. In accordance with Section 401, Article XXIII of the County Administrative Code authorize the Director, Department of Purchasing and Contracting to issue a Competitive Solicitation for a long-term health study, and upon successful negotiations and determination of a fair and reasonable price, award contracts for an initial term of two years, with three option years and up to an additional six months if needed, and to amend the contracts as needed to reflect changes to services and funding.
4. Direct the Chief Administrative Officer, or designee, to begin working with the City of San Diego and the United States Navy on an agreement to move forward in partnership for the environmental, permitting, design, and construction work and access, implementation, and maintenance necessary for the temporary infrastructure pipe extension project at Saturn Boulevard.
EQUITY IMPACT STATEMENT
Residents of South Bay communities, including Imperial Beach, Chula Vista, National City, Bonita, and East Otay Mesa, have been disproportionately affected by the Tijuana River sewage crisis. The November 2024 Assessment of Chemical Exposures by the Agency for Toxic Substances and Disease Registry and County of San Diego found that nearly two-thirds of surveyed households reported physical health symptoms and a decline in quality of life linked to contamination from the Tijuana River Valley. These impacts are concentrated in neighborhoods with higher proportions of low-income and vulnerable populations, highlighting disparities in environmental health outcomes within the region.
The initiatives presented in today’s item support the County of San Diego’s (County) efforts to better understand the health impacts of this crisis and address inequities through focused interventions within communities facing the greatest health risks. Through focused deployment of resources, implementation of environmental and health protections, and ongoing study to guide responsive strategies, the County is working to reduce exposure disparities, improve public health outcomes, and ensure safer, healthier environments for all residents.
SUSTAINABILITY IMPACT STATEMENT
The proposed actions advance the County of San Diego’s commitment to sustainable development by protecting public health, conserving water resources, and supporting responsible land management. These measures correspond with Sustainability Goal #4, which emphasizes health and well-being for all residents; Sustainability Goal #5, which focuses on the protection and stewardship of water resources; and Sustainability Goal #6, which promotes land management practices that maintain ecosystem integrity, preserve habitats and biodiversity, and support soil health while enhancing opportunities for outdoor access countywide.
Through collaboration with local, State, and federal partners, the County’s efforts focus on addressing both the ongoing effects of the Tijuana River Valley sewage crisis as well as its underlying causes. By prioritizing environmental restoration, safeguarding natural resources, and mitigating public health risks, these actions ensure that residents, visitors, and future generations can continue to benefit from the region’s diverse landscapes and ecological resources.
FISCAL IMPACT
Funds for this request are not included in the Fiscal Year 2025-26 Operational Plan. If approved, this request will be included in the Unlocked Reserves Framework which will result in a total one-time cost of $4.75 million in Fiscal Year 2025-26 including $2.0 million for the long-term health study, $250,000 for the retrospective health study, and $2.5 million for a temporary pipe extension at Saturn Boulevard. Funds for the long-term health study are contingent on $4.0 million of the study’s total cost of $6.0 million being contributed by other funders. Should alternative funding sources be identified for the pipe extension project, all or a portion of $2.5 million will support immediate needs for the Tijuana River Valley. The funding source is prior year Unrestricted General Fund Balance made available as unlocked reserves. There will be no additional staff years.
BUSINESS IMPACT STATEMENT
The Tijuana River sewage crisis continues to affect local economic activity, particularly small businesses and tourism-dependent operations in coastal and border-adjacent communities. Conditions in these areas have contributed to operational challenges and instability for local commerce.
By directing resources and implementing targeted interventions, the County of San Diego is working to stabilize commercial activity, reduce business disruptions, and support the long-term economic resilience of affected communities.
Details
ADVISORY BOARD STATEMENT
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BACKGROUND
The Tijuana River Valley (TJRV) and surrounding South Bay communities have endured decades of environmental degradation due to untreated sewage, industrial waste, and urban runoff crossing the United States-Mexico border. These conditions have resulted in recurring contamination of coastal waters, beaches, and nearby neighborhoods, with documented impacts on public health, environmental quality, and local economies in Imperial Beach, Chula Vista, National City, San Diego, Bonita, East Otay Mesa, and Coronado. Recognizing the severity of this crisis, the San Diego County Board of Supervisors (Board) proclaimed a local emergency on June 27, 2023 (6) and has continued the local emergency every 60 days, most recently on December 10, 2025 (2).
On June 24, 2025 (10), the Board established the Ad Hoc Subcommittee on the Tijuana River Sewage Crisis (Subcommittee) and adopted a five‑point plan directing the Chief Administrative Officer (CAO) to evaluate programmatic options and identify key actions and priorities to respond to this crisis. The Board’s direction included initiating an epidemiological health study on chronic exposure to hydrogen sulfide and potentially other chemicals; exploring matching funds to complete infrastructure projects to remediate toxic hot spots beginning with Saturn Boulevard; supporting air filtration/HVAC improvements in schools and childcare centers; conducting a comprehensive economic impact study; and evaluating the designation of a County of San Diego (County) County Pollution Crisis Chief (formerly referred to as Sewage Crisis Chief) to coordinate emergency response, funding, and interagency collaboration.
On September 9, 2025 (7), the Board further directed the CAO to implement an epidemiological public health impact study in affected communities and to conduct an economic impact study assessing losses to small businesses, property values, and tourism. In addition, on September 9, 2025 (18), the Board allocated funds for a feasibility study of infrastructure improvements at Saturn Boulevard to mitigate aerosolization of harmful compounds and adopted a Resolution requesting that the State Water Resources Control Board allocate Proposition 4 cross‑border rivers funding to projects addressing the ongoing environmental and public health crises in TJRV.
On September 30, 2025 (3), staff returned to the Board with updates on multiple actions, including air quality interventions, an epidemiological health study, and initiation of the Saturn Boulevard feasibility study. At that time, staff committed to work through the Subcommittee to further refine the implementation plan for priority initiatives, ensuring alignment with Board direction, scientific best practices, and community needs.
Today’s item, presented by the Ad Hoc Subcommittee on the Tijuana River Sewage Crisis, provides an update on the epidemiological public health impact study and the feasibility study for infrastructure improvements at Saturn Boulevard, directs the Chief Administrative Officer to refer the items to the Unlocked Reserves Framework, and authorizes a competitive procurement for a long-term health study.
Epidemiological Health Study
In response to Board direction, County staff, in partnership with a temporary expert professional specializing in the field of epidemiology and environmental health sciences, developed a number of epidemiological study options for consideration. In doing so, staff worked through:
• Study framework and method selection: Evaluating feasible study designs considering scientific rigor, statistical power, cost, timelines, and the ability to measure health outcomes relevant to chronic exposure.
• Data access and partnerships: Identification of prospective partnerships to access environmental monitoring data, syndromic surveillance, and de‑identified clinical encounter data, subject to privacy protections, formal agreements, and other potential approvals (i.e., Institutional Review Board).
• Equity‑centered engagement: Developing bilingual, community‑based outreach; inclusion of community advisors; and supports to reduce barriers to participation.
Staff brought to the Subcommittee the study options for consideration to finalize scope, methodology, and implementation approach before returning to the Board with recommended actions and associated funding needs. Following detailed discussions centered around prioritizing studies that yield key information about public health impacts associated with chronic exposure to hydrogen sulfide and other potentially harmful pollutants in South Bay communities, the Subcommittee has identified the following three epidemiological studies to move forward:
• Exposure Characterization Study ($250,000): This study will identify and quantify airborne chemical contaminants associated with the Tijuana River Valley sewage crisis, with a focus on the most severely affected areas. The study will also model the dispersion of these contaminants from the Tijuana River Valley, nearby beaches, and identified hot spots, and generate estimated air pollution exposure levels for residences and workplaces within the affected area to support subsequent public health analyses. Outcomes of this study will inform the long-term and retrospective studies. This study is expected to be completed within one year of commencement. Funds for this study are available within the Public Health Services budget based on the Quarter 1 Operational Plan update on December 9, 2025 (24).
• Long-term Health Study ($6.0 million): This is a multi-year study that will follow a cohort of approximately 1,000 to 2,000 individuals over time to assess potential health impacts associated with varying levels of exposure related to the TJRV sewage crisis. Participants will be selected to represent a range of exposure levels, including those in higher-impact areas. At regular intervals, participants will complete health interviews and selected assessments including one round before the hot spot mitigation if possible. The resulting data will be analyzed to identify differences in health outcomes over time between populations with higher and lower exposure levels. At the December 15, 2025 TJRV Subcommittee Meeting, it was the decision of the Subcommittee to recommend referring one-third of the cost of the study be funded by the County and seek additional funding for the remaining two-thirds putting the County’s contribution at $2.0 million.
• Retrospective Health Study ($250,000): This study will analyze existing health data - such as cancer rates, hospitalizations, and mortality - to evaluate potential associations with historical pollution exposure related to the TJRV sewage crisis. Previously collected health records would be utilized to compare trends over time and across areas with varying exposure levels. The resulting analysis would help determine whether populations in higher-impact areas experienced elevated rates of certain illnesses. This study is expected to be completed within one year of commencement.
Together, these studies will provide a more comprehensive understanding of the health risks associated with the TJRV sewage crisis, shed light on its negative impacts, and guide the allocation of interventions to the communities most affected by this crisis.
Infrastructure Feasibility Analysis at the Saturn Boulevard Hotspot
The Saturn Boulevard hotspot remains the highest priority infrastructure project within the County’s TJRV response. In response to Board direction, the County initiated a feasibility study to evaluate infrastructure mitigation options at the Saturn Boulevard hotspot, an area experiencing the aerosolization of hydrogen sulfide and other potentially harmful compounds affecting nearby neighborhoods. The feasibility study is underway and is anticipated to be completed by the end of January 2026. The feasibility analysis is designed to:
• Identify near-term operational and physical measures, as well as longer-term capital projects, to reduce emissions and community exposure.
• Define applicable permitting and environmental review pathways, including local, State, and federal requirements, and determine where compliance with the California Environmental Quality Act (CEQA) and, if applicable, the National Environmental Policy Act (NEPA) may be required based on project scope and funding sources.
• Estimate project costs, phasing, and ongoing maintenance needs to support durability and long-term performance.
• Identify potential funding strategies, including external funding opportunities and evaluation of potential County matching funds to accelerate project delivery.
An initial assessment of infrastructure alternatives and high-level cost ranges has been completed and discussed with the Subcommittee. Given the immediate need to alleviate the flows that result in aerosolization of toxic chemicals, the Subcommittee recommends moving forward with the following short-term project:
• Temporary Pipe Extension (Short-Term; $2.5 million):
o The proposed short-term option would involve adding temporary plastic pipes that extend from the end of the existing culvert pipes to the pond located downstream of the culverts. The pipe would be extended below the water surface, which would reduce turbulence and therefore prevent hydrogen sulfide and other potentially harmful compounds from becoming airborne at the location.
o This option is considered short-term in that it could be installed much faster than other alternatives given that it is not a permanent infrastructure fix. This option could be implemented within two years while working on design, permitting, and environmental analysis for any long-term solution(s).
o This option is also potentially eligible for other sources of funding. Staff should continue to apply for funding for this project, and if successful in obtaining State or federal funding for this project, the identified $2.5 million shall be used for other immediate needs in the Tijuana River Valley.
• Additional Options:
The Subcommittee will continue to work with County staff to identify additional mid- to long-term options for Saturn Boulevard, including but not limited to culvert replacement, and return to the Board of Supervisors with the Subcommittee’s recommendation.
Staff continue to coordinate with City of San Diego staff, recognizing that construction and related activities on the City property at Saturn Boulevard will require a formal agreement with the City. Staff have also been coordinating with State and federal partners to socialize the potential construction opportunity, including informal outreach to regulatory agencies such as the U.S. Army Corps of Engineers, State Water Resources Control Board, U.S. Fish and Wildlife Service, and California Department of Fish and Wildlife. Meetings with the United States Navy are also underway to explore additional coordination and support opportunities.
Residents in South Bay, who have been disproportionately affected by decades of raw sewage flowing through the TJRV, are the top concern for the Subcommittee and the County leadership. Efforts continue to collaborate with all stakeholders to advocate for effective solutions and support repairs to the failing infrastructure that underlies this binational challenge. The County is vigilant in conducting surveillance and collaborating with local, State, and federal partners on health and environmental concerns for residents in South Region.
LINKAGE TO THE COUNTY OF SAN DIEGO STRATEGIC PLAN
Today’s action aligns with the County of San Diego 2026-2031 Strategic Plan initiatives of Equity (Health) and Community (Quality of Life). This will be accomplished through multidisciplinary and interagency collaborations to address the longstanding transboundary pollution that impacts environmental justice, health, and the economy in the South Region.
Respectfully submitted,
Terra Lawson-Remer Paloma Aguirre
Supervisor, Third District Supervisor, First District
ATTACHMENT(S)
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