For over 40 years, the Tijuana River sewage crisis has devastated Imperial Beach and South Bay San Diego communities. Citizens for Coastal Conservancy (C4CC) is the only local nonprofit organization in the Tijuana River watershed with a proven, cost-effective solution to permanently end this environmental disaster.
Untreated sewage flowing daily from Tijuana
Consecutive days of beach closures in Imperial Beach
Sewage reduction with C4CC's PBCILA solution
False positive rate from faulty ddPCR testing
The Tijuana River sewage crisis represents one of the most severe and persistent environmental disasters affecting the United States-Mexico border region. For more than four decades, millions of gallons of untreated sewage, industrial waste, and toxic chemicals have flowed from Tijuana, Mexico through the Tijuana River Valley into the Pacific Ocean, contaminating beaches and coastal waters in Imperial Beach and South Bay San Diego.
This is not just an environmental problem—it's a public health emergency, an economic catastrophe, and an environmental justice issue that disproportionately impacts low-income communities of color in Imperial Beach. Residents have endured toxic air quality, perpetual beach closures, plummeting property values, and devastating impacts to local businesses that depend on coastal tourism.
Every single day, approximately **100 million gallons** of untreated or partially treated wastewater flows from Tijuana toward the United States. When Tijuana's aging wastewater infrastructure fails—which happens regularly—raw sewage pours through canyon systems and the Tijuana River, carrying not just human waste but also industrial chemicals, heavy metals, pharmaceutical residues, and pathogenic bacteria into American waters.
Imperial Beach, the southernmost beach city in California, has borne the brunt of this crisis. The city's beaches have been closed for **over 1,000 consecutive days**—nearly three full years—due to sewage contamination. Residents cannot safely swim, surf, or even walk on their own beaches. Children cannot play in the sand. Local surf shops, restaurants, and hotels have lost millions of dollars in revenue. Property values have declined as potential buyers refuse to invest in a community where the ocean smells like a sewer.
The Tijuana River sewage crisis stems from decades of inadequate investment in wastewater infrastructure in Tijuana, Mexico. Tijuana's population has exploded from approximately 300,000 residents in 1970 to over 2 million today, but the city's sewage treatment capacity has not kept pace with this rapid growth.
Tijuana's primary wastewater treatment facility, the San Antonio de los Buenos plant, was designed to treat a fraction of the sewage the city now generates. The facility frequently operates beyond capacity, breaks down, or simply bypasses treatment entirely, discharging raw sewage directly into the Pacific Ocean just south of the U.S.-Mexico border. From there, ocean currents carry the contamination north to Imperial Beach and Coronado.
Additionally, Tijuana's sewer collection system is aging and poorly maintained. Sewer pipes crack and leak. Pump stations fail. During rainstorms, the system becomes overwhelmed, and millions of gallons of untreated sewage overflow into canyons that drain directly into the Tijuana River Valley. These "transboundary flows" cross the international border and pollute American soil and water.
The health consequences of the Tijuana River sewage crisis are severe and well-documented. Untreated sewage contains dangerous pathogens including E. coli, Salmonella, Hepatitis A virus, and antibiotic-resistant bacteria. Exposure to contaminated water can cause gastrointestinal illness, skin infections, respiratory problems, and serious diseases.
But the health impacts extend beyond direct water contact. Recent research has shown that sewage-related bacteria and pathogens can become **aerosolized**—suspended in the air—creating an airborne health hazard for residents living near the Tijuana River Valley. Imperial Beach residents, including U.S. Navy SEALs who train at Naval Amphibious Base Coronado, have reported chronic respiratory illnesses, skin rashes, and other health problems linked to exposure to contaminated air and water.
Children, elderly residents, and individuals with compromised immune systems face the greatest health risks. Yet these vulnerable populations have no choice but to live with the constant threat of sewage exposure because they cannot afford to move away from Imperial Beach, one of the most affordable coastal communities in San Diego County.
The economic toll of the Tijuana River sewage crisis on South Bay communities is staggering. Imperial Beach's tourism industry—once a vital economic engine—has been decimated by perpetual beach closures. Surf shops have closed. Restaurants have lost customers. Hotels report declining occupancy rates. Real estate values have plummeted as buyers avoid a city where beaches are permanently closed and the air smells like sewage.
A 2019 economic analysis estimated that the sewage crisis costs the South Bay region **over $37 million annually** in lost tourism revenue, decreased property values, and increased healthcare costs. These losses fall disproportionately on Imperial Beach, a working-class community with limited financial resources to absorb such devastating economic impacts.
The Tijuana River sewage crisis is fundamentally an **environmental justice issue**. Imperial Beach is a predominantly Latino, working-class community with a median household income well below the San Diego County average. Residents lack the political power and financial resources of wealthier coastal communities like La Jolla or Del Mar.
For decades, Imperial Beach residents have been told to wait—wait for binational agreements, wait for federal funding, wait for new treatment plants that may never be built. Meanwhile, wealthier communities would never tolerate such conditions. The message is clear: Imperial Beach residents are expected to accept living conditions that would be considered unacceptable anywhere else in San Diego County.
This is why C4CC's work is so critical. We are the only local nonprofit organization fighting specifically for Imperial Beach and South Bay communities, demanding that government agencies implement real solutions now—not decades from now.
While government agencies have spent decades debating expensive, long-term infrastructure projects, Citizens for Coastal Conservancy has identified a **proven, cost-effective solution** that can be implemented immediately using existing infrastructure: operating the PBCILA (Punta Bandera Collector Interceptor and Lift Station) pump station at full capacity, 24 hours a day, 7 days a week.
PBCILA is a critical wastewater infrastructure facility located in Tijuana, Mexico, just south of the U.S.-Mexico border. The facility consists of a network of sewage collectors that intercept untreated wastewater flowing through canyons toward the Tijuana River, and a pump station that lifts this sewage and diverts it to Tijuana's wastewater treatment system.
PBCILA was specifically designed to prevent transboundary sewage flows—sewage that would otherwise cross into the United States and pollute the Tijuana River Valley. When PBCILA operates at full capacity, it can intercept and divert approximately **78 million gallons per day** of sewage that would otherwise flow into American territory.
C4CC's analysis shows that operating PBCILA at full capacity 24/7 would reduce transboundary sewage flows by **78%**—from approximately 100 million gallons per day to just 22 million gallons per day. This dramatic reduction would:
Importantly, this solution uses **existing infrastructure**. PBCILA has already been built. The pump station already exists. The collectors are already in place. We don't need to wait for new construction, environmental reviews, or binational agreements. We simply need to operate the facility at its designed capacity.
This is the question that drives C4CC's advocacy work. PBCILA was designed to operate 24/7, but Mexican authorities have historically operated the facility at reduced capacity or shut it down entirely during certain periods. The reasons are complex and involve funding constraints, operational challenges, and lack of political will.
C4CC believes that the United States government must take a more active role in ensuring PBCILA operates at full capacity. This could involve providing operational funding, technical assistance, or diplomatic pressure. The cost of operating PBCILA 24/7 is a fraction of the cost of building new treatment plants—yet the benefits to Imperial Beach would be immediate and substantial.
C4CC's PBCILA solution is not meant to replace long-term infrastructure investments. New wastewater treatment capacity is still needed in Tijuana. The South Bay International Wastewater Treatment Plant in the United States needs expansion. Canyon collectors need maintenance and upgrades.
However, these long-term projects will take **years or even decades** to complete. Imperial Beach residents cannot wait that long. Operating PBCILA at full capacity provides **immediate relief** while long-term solutions are being developed and implemented.
C4CC is the only organization advocating specifically for this immediate, proven solution. While other groups focus on long-term planning, we are fighting for action today.
In addition to advocating for the PBCILA solution, C4CC has conducted groundbreaking original research exposing a second crisis that is making the Tijuana River sewage crisis even worse: **faulty water quality testing** that closes beaches even when water is safe.
In May 2022, San Diego County's Department of Environmental Health and Quality (DEHQ) switched from the EPA-approved Enterolert testing method to a newer molecular method called droplet digital PCR (ddPCR). County officials claimed this new method would provide "faster results" and "better protect public health."
But C4CC's investigation revealed a shocking truth: **ddPCR was never properly validated** against EPA requirements, and the testing method has a documented **56% false positive rate**. This means that more than half the time ddPCR says a beach should be closed, the approved EPA testing method would say it's safe to swim.
The impact of switching to ddPCR has been devastating. At Coronado beaches—located miles north of the Tijuana River and not directly impacted by sewage flows—beach closures increased by **1,586%** after the County switched to ddPCR testing. Let that sink in: beaches that were open 96% of the time under the approved testing method are now closed 61% of the time under ddPCR.
These are not beaches that suddenly became 17 times more polluted. These are beaches being closed because of a faulty testing method that detects DNA from dead bacteria and biological debris that pose no health risk.
The EPA-approved Enterolert method detects only **live, culturable bacteria** that can grow and potentially cause infection. If bacteria are dead or damaged, Enterolert won't count them—because dead bacteria can't make you sick.
ddPCR, by contrast, detects **all bacterial DNA**, including DNA from dead bacteria, non-culturable bacteria that can't cause infection, and free-floating DNA fragments in the water. After storms or sewage spills, dead bacteria and DNA fragments can persist in the water for days or weeks. Enterolert correctly identifies that these remnants pose no health risk. ddPCR triggers beach closures based on genetic material from bacteria that died long ago.
C4CC's research, published in a peer-reviewed scientific journal, analyzed water samples collected simultaneously from Coronado beaches during summer 2023. Researchers tested the same water using both Enterolert and ddPCR to see if the methods agreed. The results were damning:
Neither EPA requirement was met. Yet San Diego County continues to use ddPCR to make beach closure decisions that affect millions of residents and visitors.
The false positive problem is worst at Imperial Beach and South Bay beaches—the communities closest to the Tijuana River. These beaches experience genuine sewage contamination, but they also experience the highest false positive rates from ddPCR testing. This means that even when actual sewage flows decrease, beaches remain closed because ddPCR continues to detect DNA from bacteria that died days or weeks earlier.
C4CC is demanding that San Diego County return to the EPA-approved Enterolert testing method until ddPCR can be properly validated. Imperial Beach residents deserve accurate information about water quality—not beach closures based on a faulty testing method that fails EPA's own standards.
Behind the statistics and scientific research are real people whose lives have been devastated by the Tijuana River sewage crisis. Imperial Beach residents have endured decades of broken promises, perpetual beach closures, and declining quality of life.
"I moved to Imperial Beach because I wanted my kids to grow up near the ocean. Now I can't even let them play on the beach. The smell is unbearable some days. We're trapped here because we can't afford to move, and no one wants to buy our house."
— Imperial Beach resident and mother of two
"I've owned a surf shop here for 15 years. Business is down 60% since the beach closures became permanent. I've had to lay off employees. I don't know how much longer I can survive."
— Local business owner
"We train Navy SEALs in these waters. Our personnel are getting sick—respiratory infections, skin rashes, gastrointestinal illness. This is a national security issue, not just an environmental problem."
— U.S. Navy official (name withheld)
These stories represent just a fraction of the human toll of the Tijuana River sewage crisis. Thousands of Imperial Beach residents face these conditions every single day, with no end in sight.
This is why C4CC's work is so urgent. We are fighting not just for clean water and open beaches, but for the health, economic survival, and basic dignity of Imperial Beach communities.
The Tijuana River sewage crisis is a decades-long environmental disaster where millions of gallons of untreated sewage and industrial waste flow from Tijuana, Mexico into the Tijuana River Valley and Pacific Ocean, contaminating beaches in Imperial Beach and South Bay San Diego. The crisis has resulted in over 1,000 consecutive days of beach closures, devastating local economies and public health.
The crisis is caused by inadequate wastewater infrastructure in Tijuana, Mexico, where aging sewer systems cannot handle the city's rapid population growth. When Tijuana's sewage treatment plants fail or reach capacity, untreated sewage flows through canyons and the Tijuana River into the United States, polluting Imperial Beach and South Bay coastal waters.
C4CC advocates for operating the PBCILA (Punta Bandera Collector Interceptor and Lift Station) pump station at full capacity 24/7. This proven, cost-effective solution can reduce transboundary sewage flow by 78% (from 100 million gallons per day to 22 MGD) using existing infrastructure, at a fraction of the cost of building new treatment plants.
San Diego County switched to an unvalidated ddPCR testing method in 2022 that has a 56% false positive rate. This faulty testing closes beaches even when water is safe, increasing beach closures by 1,586% at some locations. C4CC's original research exposed this issue, showing that more than half of beach closures are false alarms caused by the testing method, not actual sewage contamination.
You can support C4CC's advocacy work by donating, volunteering, contacting elected officials to demand action on PBCILA and ddPCR testing, sharing our research and media kit with journalists and policymakers, and attending our community meetings to stay informed and get involved. Every voice matters in the fight for clean beaches and healthy communities.