Sewage Disaster Shocks San Diego—Billions of Gallons Unchecked!

Billions of gallons of untreated sewage from Mexico continue flooding San Diego’s beaches and air in 2026, exposing a transboundary crisis that federal promises under President Trump have yet to fully resolve, leaving communities on both sides of the border breathing toxic fumes and dodging health risks.

Story Snapshot

Since October 2023, 31 billion gallons of raw sewage, polluted stormwater, and trash have flowed from the Tijuana River into San Diego County, forcing over 1,000 days of beach closures in Imperial Beach.[1][4]
Hydrogen sulfide gas from the river spikes to 300-600 parts per billion, causing respiratory illnesses in South Bay schools and neighborhoods.[2][4]
July 2025 U.S.-Mexico agreement commits $93 million to divert 10 million gallons per day by year’s end, but dry weather flows still hit 15-40 million gallons daily into U.S. waters.[3][4]
Local businesses report 74% negative impacts and 50% revenue losses from pollution, fueling bipartisan frustration with government inaction.[1]

Sewage Flows Cross Border Daily

San Diego Coastkeeper reports 31 billion gallons of raw sewage, polluted stormwater, and trash entered the Tijuana River Valley and Pacific Ocean since October 2023.[1] Dry weather flows average 35-40 million gallons per day into the U.S., dropping to about 15 million gallons after partial restarts of Mexico’s PBCILA facility.[4] Wet weather overflows from overwhelmed infrastructure in Tijuana exacerbate the issue, carrying untreated wastewater through the main channel and canyon collectors.[8] Beaches in Imperial Beach and Coronado close for over 1,000 consecutive days due to fecal contamination.[4]

January 2026 saw a spill of millions of gallons, with 11 million gallons per day of untreated wastewater entering the Tijuana River during repairs to Mexico’s International Collector Project.[2] Mexico completed fixes in three days, but historical events like the 2017 spill of 143-200 million gallons highlight recurring failures.[5] Ocean currents carry discharges from Mexico’s Punta Bandera outfall north to San Diego coasts.[4]

Airborne Toxins Threaten Health

Hydrogen sulfide gas, a byproduct of decomposing sewage, aerosolizes from polluted hotspots like Saturn Boulevard in South San Diego County.[1] County sensors at sites including Berry Elementary record spikes above 300 parts per billion, far exceeding the safe 5 parts per billion threshold.[4] Warm weather in March 2026 worsened airborne concentrations, triggering unsafe air warnings and respiratory complaints in nearby communities.[1]

San Diego Air Pollution Control District monitors three stations along the river, confirming elevated toxins from industrial waste and untreated flows.[4] Surfers, swimmers, and Navy SEALs training in Coronado report illnesses, while South Bay residents endure nausea and breathing problems.[1][2] A 2023 survey shows 74% of local businesses harmed, with 50% losing significant revenue from beach closures and odors.[1]

U.S.-Mexico Efforts Fall Short

Environmental Protection Agency Administrator Lee Zeldin announced a July 2025 memorandum of understanding with Mexico’s Secretary Alicia Bárcena Ibarra to end decades of raw sewage flows.[3] Mexico pledged $93 million from Minute 328 funds for a 10 million gallons per day diversion and infrastructure upgrades by December 31, 2025.[3] Partial restarts at Punta Bandera and San Antonio de los Buenos plants restored 18 million gallons per day capacity in April 2025.[1]

San Diego leaders are trying to speed up solutions to sewage pollution from the Tijuana River, while investigating the scope of the problem. https://t.co/JqXL66xKkj

📸 Adriana Heldiz pic.twitter.com/dPbGlSfIcW

— CalMatters (@CalMatters) May 8, 2026

San Diego County allocated $2.5 million for Saturn Boulevard fixes and seeks $25 million from Proposition 4 climate bonds.[1] State bills aim to tighten air standards and speed funding.[1] Despite these steps, dry flows persist at 15 million gallons per day, and U.S. infrastructure like the South Bay plant remains in disrepair.[1][8] Communities across the political spectrum voice frustration that distant federal and binational bureaucracies prioritize diplomacy over urgent fixes for everyday Americans.