A yearslong sewage crisis at the US-Mexico border is getting addressed by feds

After years of pollution from sewage flowing across the U.S.-Mexico border and onto San Diego beaches, federal officials are stepping in. 

At least “100 billion gallons of untreated sewage, industrial waste, and urban runoff have spilled into the Tijuana Estuary and the Pacific Ocean via the Tijuana River and its tributaries” in the last five years, according to the International Boundary and Water Commission (IBWC), prompting beach closures for more than 700 consecutive days, San Diego State University researchers stated in a study released in February.

The South Bay International Wastewater Treatment Plant, in San Diego County, treats sewage from Tijuana, Mexico, before pumping it into the Pacific Ocean. Now, a $600 million project has been approved that should allow officials to repair and rehabilitate the wastewater treatment plant, the United States Section of the IBWC said in a Wednesday news release. The design phase is expected to take up to 20 months and construction is expected to take a maximum of five years, but contractors are aiming to decrease that time by up to 18 months and the plant is expected to remain operational throughout, the water commission said in the release. 

The repairs are being done to “better handle the wastewater coming across the border from Mexico, which will improve the lives of communities on both sides of the border,” Frank Fisher, a spokesperson for the water commission, said in an email to SFGATE. 

Some of the repairs include expanding the treatment plant to be able to move an average of 50 million gallons of water per day, rather than its current capacity of 25 million gallons per day, with a peak flow capacity of 75 million gallons per day, the water commission stated. 

Fisher said the plant, which was built in 1997, is long overdue for repairs. 

“The main problem is not the plant, it’s the polluted Tijuana River and Mexico’s discharging of untreated sewage directly into the ocean,” he said. “However, due to lack of funding and deferred maintenance, the plant is seriously in need of repair, rehabilitation and expansion in order to better handle the increasing flow from Mexico, so that’s why we’re doing this project.”

According to the San Diego State study, the waters of the Tijuana River and Estuary area in the U.S. are “severely contaminated,” posing a public health threat. And the pollution doesn’t stop there, as it has been affecting San Diego County’s coastline.

Many beaches in San Diego have closed periodically because of high bacteria levels, with the current closures being at Silver Strand, Imperial Beach and Tijuana Slough (closed since Dec. 8, 2021). Imperial Beach has been closed since Dec. 18, 2023, and was named the most polluted beach in the country in a recent study. 

The excessive sewage is not only harmful to the waters, but researchers said it is affecting residents in the area. The potential health risks to nearby communities include “harmful viruses, bacteria and parasites as well as toxic chemicals in water and air,” San Diego State’s School of Public Health researchers said in the February report.

“The possibility for a heightened incidence of illnesses linked to the influx and constant exposure to wastewater into California communities along the U.S.-Mexico border should be investigated,” the report stated.

The flow has been increasing over time, but the amount of sewage-contaminated water moving through the U.S.-Mexico border and into San Diego County in 2023 was the highest in recent years when it reached more than 44 billion gallons — the highest volume since 2000, the Los Angeles Times reported. 

Several sewage spills have also occurred over the years, adding to the increased contamination. 

There was a wastewater spill on June 17 at the Hollister Pump Station, which routes to the wastewater treatment plant, according to the water commission. By the time it was resolved on June 19, it had resulted in over 300,000 gallons of wastewater spillage.   

Officials said the pump station was overwhelmed with “significant amounts of sediment,” partly due to winter storms, in an Aug. 12 letter to the San Diego County Air Pollution Control District from the water commission. The letter was in response to a violation notice issued by the District on July 29 regarding the Hollister Pump Station. 

Officials said updates about the treatment plant project will be provided at the water commission’s Citizens Forum meetings.