San Diego Beaches: Polluted Paradise?

San Diego is known for its picturesque beaches, but are they polluted? In 2024, San Diego County was ranked among the top 10 most polluted locations in California, with Imperial Beach in San Diego at the top of the list due to toxic water from the Tijuana River Watershed. The Beach Report Card, released by Heal the Bay, assigns letter grades to beaches based on bacterial pollution levels, and four San Diego County beaches made the Beach Bummer list due to sewage issues. The Tijuana River, which carries sewage from Tijuana, is a significant contributor to the pollution, impacting beaches such as the Tijuana River Mouth, Tijuana Slough, and Imperial Beach. While ocean water tends to be clean, urban runoff, stormwater, and sewage failures can contaminate it. San Diego's beach water quality has shown a decline, with an increase in sewage spills due to overtaxed sanitation systems and outdated infrastructure.

Sewage spills from Tijuana River

San Diego is home to the nation's most polluted beach, according to a report by a non-profit environmentalist group. Imperial Beach in San Diego topped the list, with every sample collected showing bacteria counts that exceeded the state's health standard for recreational waters. The beach has been closed for over two years due to toxic water from the Tijuana River Watershed flowing into the ocean.

The Tijuana River has been at the centre of a transboundary pollution crisis on the US/Mexico border for decades, impacting public health, local ecosystems, and the economy. The crisis has escalated in recent years due to the rapid population growth and urban expansion of Tijuana, which has overwhelmed the sewage treatment plant, leading to frequent overflows and breakdowns. Since October 2023, 31 billion gallons of raw sewage, polluted stormwater, and trash have flowed down the Tijuana River, closing numerous San Diego beaches and posing major public health risks.

The untreated sewage contains high levels of nutrients, bacteria, toxins, heavy metals, and chemicals, which have severe ecological consequences. It leads to algal blooms that deplete oxygen in the water, causing die-offs of fish and other marine organisms. Pollutants accumulate in the tissues of marine mammals, affecting their long-term health and reproductive success, and ultimately destabilizing food webs and degrading the health of critical habitats.

The pollution crisis has also had a significant impact on the local economy, particularly tourism, as visitors are discouraged from visiting some of San Diego's most popular coastal areas. Furthermore, the contamination has resulted in public health concerns, as toxic chemicals and microbes in raw sewage, industrial waste, and urban runoff can be airborne and linger in soils, potentially affecting the health of community members, including children and the elderly.

The situation has sparked calls for action from local officials, with Imperial Beach Mayor Paloma Aguirre urging the involvement of San Diego County, the California Department of Health, and the Centers for Disease Control and Prevention to actively monitor and address the issue.

San Diego's Beach Water Quality Tests

San Diego's beaches are considered some of the most polluted in the nation. The Tijuana River, which carries sewage from Tijuana, empties at the Tijuana Slough National Wildlife Refuge, and has been cited as the reason for the poor water quality at San Diego's beaches. The Beach Report Card 2024, issued by Heal the Bay, gave F grades to four San Diego County beaches, all of which are adjacent to the Tijuana River: Tijuana River Mouth, Tijuana Slough, Imperial Beach at Seacoast Drive, and Border Field State Park.

The Beach Report Card issues A-to-F grades to over 700 beaches on the Pacific Coast, based on levels of bacterial pollution. The lower the grade, the higher the chance of swimmers getting sick. While 89% of California beaches received A or B grades during the dry-weather summer months, the winter season saw this number drop to 66%.

The pollution in the Tijuana River is due to inadequate sanitation infrastructure in Tijuana. The river annually discharges tens of millions of gallons of untreated sewage into the ocean. Sewage concentrations at San Diego's beaches are often 35 times higher than what is considered safe for human contact.

The city of San Diego has changed how it communicates sewage pollution to the public. A failed water quality test alone will not result in a beach closure. This has resulted in beaches being closed less often, despite the water being more polluted.

San Diego residents are advised to check the latest beach advisories and closures before heading to the beach. It is also recommended to avoid going into the water for 72 hours after rainfall, as urban runoff and stormwater end up in the ocean, and to pay attention to local pollution advisories.

Bacterial pollution levels

San Diego County beaches have been ranked among California's dirtiest beaches, with four beaches making it to the Beach Bummer list. The Tijuana River, which carries sewage from Tijuana, empties at the Tijuana Slough National Wildlife Refuge, resulting in bacterial pollution. The Beach Report Card, released by Heal the Bay, assigns letter grades from A to F to beaches based on bacterial pollution levels. In 2023-24, nearly 90% of monitored California beaches received A or B water-quality grades during the dry-weather summer months, a slight decrease from previous years.

The Tijuana River is a significant source of pollution, discharging tens of millions of gallons of untreated sewage into the ocean annually due to inadequate sanitation infrastructure in Tijuana. This has led to persistent sewage issues in San Diego County beaches, with Imperial Beach, Tijuana Slough, and Border Field State Park being among the most affected. The sewage problem is not limited to the Tijuana River, as other creeks and rivers that discharge into the ocean also contribute to the bacterial pollution.

The effects of sewage pollution on the water have raised concerns, with reports of people in the community falling sick. The situation has been described as a "dire" one, impacting the health of California residents. The bacterial pollution levels in the water can have adverse effects on those who come into contact with it, increasing the chances of ocean-goers getting sick.

While ocean water tends to be cleaner, it can become contaminated after rainfall when urban runoff and stormwater make their way to the beach. Creeks and rivers that flow through urban areas are particularly susceptible to pollution from road runoff, sewage infrastructure issues, and improper waste disposal. Beachgoers are advised to avoid the water for 72 hours after rainfall and to pay attention to local pollution advisories to minimise potential health risks.

Upgrades and enhancements are currently underway to improve the situation, including EPA-funded upgrades to the Punta Bandera treatment plant and the South Bay International Wastewater Treatment Plan. However, these improvements may take a decade or more to complete. In the meantime, beachgoers are advised to be cautious and stay informed about water quality and safety before visiting San Diego's beaches.

Climate change and aging infrastructure

San Diego has committed to tackling climate change and improving its infrastructure to protect its beaches and communities. The city has implemented a Climate Action Plan (CAP) with a community-wide goal of achieving net-zero emissions by 2035. This plan includes transitioning all city facilities to 100% renewable energy, increasing the number of electric vehicles, and improving indoor and outdoor air quality.

However, San Diego faces challenges due to aging infrastructure and the impacts of climate change. The city's beaches have been affected by pollution, with Imperial Beach in San Diego being identified as the nation's most polluted beach due to toxic water flowing into the ocean. Sewage pollution and urban runoff contribute to the contamination of beach water, impacting the health of the community.

The city's infrastructure, particularly its sewer and flood management systems, may struggle to cope with the predicted increase in intense storms and rainfall caused by climate change. San Diego's Climate Action Plan aims to address these issues by focusing on greening the city, restoring salt marshlands, and increasing the local water supply through the Pure Water San Diego program.

Additionally, the city is taking steps to mitigate the impacts of extreme heat, another consequence of climate change. The Climate Action Plan includes initiatives such as expanding access to "Cool Zones", increasing the number of trees in the urban forest, and promoting the use of renewable energy to reduce the urban heat island effect and provide relief during heatwaves.

Through its Climate Action Plan and community engagement, San Diego is working towards a more sustainable future. The plan's implementation will be a collaborative effort involving various city departments and community feedback to ensure a resilient and equitable transition to net zero.

Unsafe bacteria levels in water

San Diego's beaches are some of the most polluted in the nation, with the Tijuana River being a significant source of the problem. The river annually discharges tens of millions of gallons of untreated sewage into the ocean, originating from inadequate sanitation infrastructure in Tijuana. This has led to persistently unsafe bacteria levels in the water, with every sample collected from Imperial Beach in San Diego exceeding the state's health standards for recreational waters.

The Beach Report Card, an annual report released by Heal the Bay, assigns letter grades to beaches based on bacterial pollution levels. In 2023-2024, four San Diego County beaches made the "Beach Bummer" list, with the Tijuana River Mouth topping the list of the most polluted beaches. The report also noted that while Southern California beaches from Santa Barbara to San Diego received mostly A or B grades in the summer, the overall water quality in the state dipped during the winter months due to increased rainfall and sewage spills.

The impact of polluted water is not just limited to the ocean but also affects nearby creeks and rivers. For example, the San Luis Obispo Creek in San Luis Obispo discharges into the ocean at Avila Beach, and 35% of the samples collected yielded unsafe bacteria levels. Similarly, the San Pedro Creek in Linda Mar Beach, a popular surf spot, channels urban runoff directly into the ocean, impacting the water quality.

The high levels of bacteria in the water can have significant health impacts on those who come into contact with it. Jody Harwood of the University of South Florida's Water Institute likened swimming in the polluted water to "swimming in a mixed-up turd in a bucket." The situation has led to calls for a state of emergency, with local communities reporting illnesses and urging the government to address the issue.

To address the problem of unsafe bacteria levels, enhancements are underway at the Punta Bandera treatment plant and the South Bay International Wastewater Treatment Plan, with funding from the U.S. EPA. However, these upgrades may take a decade or more to complete, and beachgoers are advised to avoid swimming at these beaches until the improvements are finished. In the meantime, it is recommended to check for beach advisories and closures before visiting San Diego's beaches and to avoid entering the water for 72 hours after rainfall to minimize the risk of exposure to unsafe bacteria levels.

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