South Region Health Concerns

What the County is Doing

The County of San Diego cares for South Region residents and what they are experiencing around health and quality of life issues. County of San Diego officials are working with partners and other agencies to assess concerns and impacts from sewage and pollution in the Tijuana River Valley and surrounding communities.

On this page:

• Background
• Ongoing Efforts
• Multi-Agency Coordination
• Communications

In September 2023, the Public Health Services (PHS) department in the County of San Diego Health & Human Services Agency (HHSA) was notified of a possible increase in “gastrointestinal (GI) illnesses” in the South Region. Since being alerted, PHS regularly:

• Reviews San Diego County and regional data for trends in GI illnesses.
• Reviews GI illness data from two additional clinics in the same geographic area.
• Places PHS staff in the area to collect and review client data related to sewage spill related illnesses.
• Meets with local agencies, including the Department of Environmental Health and Quality (DEHQ) and San Diego Air Pollution Control District (SDAPCD).
• Meets with state agencies, including the State Public Health Officer, California Department of Public Health (CDPH); Environmental Protection Agency (EPA); the Coastal Commission; and the Tijuana River Pollution Task Force.  

To date, there have been no significant increases in reportable GI illness in the South Region.

• Surveillance and investigation are ongoing.
• The County Board of Supervisors has expressed its concerns, including on June 27, 2023, when the Board issued a Proclamation of Local Emergency for environmental and economic impacts due to the U.S-Mexico transboundary pollution crisis. The Board has continued to renew the local emergency every 60 days.
  

The County continues its efforts to determine public health risks to keep community members in San Diego County safe, healthy, and thriving. Learn more about health information regarding Contaminated Water and Environmental Odors.

A combination of several factors has led to the overflow of sewage, causing runoff water and contamination to go into the ocean on both the Mexico and U.S. sides, including:

• Infrastructure issues at sewage treatment plants on the Mexico side of the border,
• Maximum capacity to process sewage at the U.S. operated International Wastewater Treatment Plant (IWTP) located in the international boundary zone in the Tijuana River Valley Region, and
• The region’s growing population and increased frequency of rain/storms leading to an increase in the volume of water flow that is larger than the plant was originally designed to handle. 

Short and long-term fixes depend on major infrastructure repair on both sides of the border. The International Boundary and Water Commission (IBWC) oversees the sewage treatment plant on the U.S. side of the border. It is a federal facility that receives funding from the federal government. The Mexican sewage treatment plant is overseen by the Mexican government.

• The Tijuana watershed, which is located primarily in Mexico, sends most stormwater, unregulated flows, and sewage overflows into the Tijuana River Valley which is the principal connection to the ocean.
• The Tijuana River Valley is mostly located on the U.S. side of the border and parallels Imperial Beach as it reaches the Pacific Ocean.
• The County Board of Supervisors has expressed its concerns, including on June 27, 2023, when the Board issued a Proclamation of Local Emergency for environmental and economic impacts due to the U.S-Mexico transboundary pollution crisis. The Board has continued to renew the local emergency every 60 days.

There are multi-agency efforts to address air and water quality issues in the Tijuana River Valley that are impacting San Diego area communities.

• Air Quality (cross-border flows generate odors and impact air quality):
  • Lead Agency Role – San Diego County Air Pollution Control District (SDAPCD): Monitors air quality in San Diego County, including near the Tijuana River Valley and ensures air quality meets federal and state standards. Its primary role is to enforce federal, state, and local air quality laws and regulations to reduce air pollution. SDAPCD also responds to air quality complaints and issues air quality advisories.
  • Support Agency Role – California Air Resources Board (CARB): Provides technical assistance and guidance on air monitoring and air filtration for hydrogen sulfide and other harmful emissions.
  • Support Agency Role – US Environmental Protection Agency (EPA) – Air Division: Provides technical guidance on regional and community-scale air quality monitoring.
  • Support Agency Role – US EPA Superfund Emergency Management Division: Available to respond as necessary to provide monitoring data and serve as a force-multiplier for emergency response efforts.
     
• Public Health (health impacts related to water and air quality):
  • Lead Agency Role – County HHSA: Monitors and analyzes data, investigates health concerns, provides education and outreach for prevention of disease, and provides public health recommendations based on air and water quality monitoring.
  • Support Agency Role – California Department of Public Health & US Center for Disease Control: Provides health impact research, technical advice, and resources for public health initiatives related to waterborne diseases and air quality concerns, particularly in vulnerable communities.
     
• Infrastructure (impacts related to untreated sewage flows):
  • Lead Agency Role – U.S. Section IBWC: Runs the South Bay International Wastewater Treatment Plant and coordinates with the Mexican Section IBWC to eliminate transboundary flows. Helps implement Minute 328 projects.
  • Support Agency Role – US EPA – Water Division: Provides funding and oversight for wastewater infrastructure projects to further reduce cross-border flows into the U.S. Shares data and research findings to inform decision-making and policy development.
     
• Water Quality (Cross-border flows have impacted local resources and way of life):
  • Lead Agency Role – San Diego Regional Water Quality Control Board (SDRWQCB): Regulates water quality and protects the beneficial uses of the Tijuana River, Estuary, and coastal waters through permits and requires monitoring of water quality. Leads the Tijuana River Valley Recovery Team and coordinates state, local, and federal efforts to mitigate impacts of cross-border pollution.
  • Support Agency Role – San Diego County Department of Environmental Health and Quality (DEHQ): Monitors recreational beach and bay water quality daily and issues water contact closures and advisories to inform, educate, and protect the public.

For more information:

• Air Quality - San Diego Air Pollution Control District: airinfo@sdapcd.org
• Beach & Bay Water Quality - San Diego County Environmental Health and Quality: beachandbay@sdcounty.ca.gov
• Public Health - San Diego County Public Health Services: phs.southregionhealth.hhsa@sdcounty.ca.gov
• Wastewater Infrastructure Planning - U.S. Environmental Protection Agency: Tijuanawater@epa.gov
• Wastewater Infrastructure Operations - U.S. International Boundary and Water Commission: PAO@ibwc.gov  
• Water Quality - SD Regional Water Quality Control Board: rb9_questions@waterboards.ca.gov

Multi-Agency Coordination Fact Sheet

County News Center Updates

• County Hears from More Than 2,100 People on Impacts of Tijuana River Valley Sewage (November 25, 2024)
• County Hears from Nearly 2,000 People on Impacts of Tijuana River Valley Pollution (November 15, 2024)
• Tijuana River Valley Pollution Survey Completion Rate Passes 1,000 Mark (November 4, 2024)
• A Second Federal Tijuana River Valley Health Survey Starts Today (October 21, 2024)
• CDC and County Launch Health Survey in Tijuana River Valley (October 18, 2024)
• Tijuana River Valley Health Assessment in Partnership with CDC Begins (October 17, 2024)
• Volunteers Fan Out in Sewage Impacted South County Neighborhoods (October 4, 2024)
• County Distributing Information to Residents Ahead of CDC Community Health Assessment (October 2, 2024)
• County Expands its Health-Focused Response to Tijuana River Valley Sewage Crisis (September 5, 2024)
• County Supervisors Expand Efforts to Improve Tijuana River Valley (October 24, 2023)

California Health Alert Network San Diego (CAHAN) 

• Health Advisory: Cross-border pollution in the Tijuana River Valley and potential health effects (September 13, 2024)

California Department of Public Health (CDPH)

• CDPH Review of SDCPHS November 2023 Response to Reports of Increased Infectious GI Illness (October 21, 2024)