One weekend, Parker Shinn was contemplating, like many Coronadans do, the frequent beach closures in his city caused by the ongoing Tijuana sewage crisis.
Then, an idea came to him. It took about an hour for him to consider the specifics, and then a weekend’s research to investigate its cost and feasibility.
Shinn is proposing a temporary solution that he hopes will prevent beach closures during the next several years as the US and Mexico complete projects designed to address the problem.
“It seems that leaders have all conceded that this is going to take another five years to be addressed,” Shinn said. “I just don’t think that this is an acceptable answer.”
Every day, million of gallons of untreated sewage from Tijuana are dumped into the Pacific Ocean, contaminating coastal waters in the South Bay and, at times, as far north as La Jolla.
The surf also aerosolizes bacteria from the sewage, prompting health concerns even for people who do not venture into the water. A study in 2023 found bacteria in the air, and a San Diego State University study published May 28 found the same.
Shinn proposes a two-mile outfall pipeline to take sewage offshore as a temporary solution. This, he said, will get the sewage away from the surf and would take two to three months and $7 million to install. His full plan is outlined on his website.
He also proposes that the sewage is treated in-pipe with peracetic acid, a disinfectant with a higher oxidation potential than chemicals like chlorine. Recent studies have found it a promising treatment of wastewater, although it is a new method whose studies have largely been conducted in laboratory rather than field environments.
A 2023 pilot study used peracetic acid, or PAA, as one of six treatment methods at a wastewater treatment plant near Lisbon, Portugal. Although the treatment did not generate water that was reusable by European Union standards, it enhanced the water quality. Researchers concluded that PAA is a promising potential treatment for wastewater with more development.
But, Shinn said, he’s not looking for a permanent, long-term solution. He’s trying to stop beach closures as quickly as possible and utilize in-pipe disinfection to help mitigate pollution. The byproducts of PAA when used to treat wastewater are acetic acid (the main component in vinegar), water, and oxygen.
“This really is a health crisis, and that’s my number-one concern,” Shinn said, citing the US Navy SEALs who have been training in contaminated water in Coronado. “Secondarily, this has had a major economic impact in the region. A lot of local businesses depend heavily on people going to the beach. For me as a resident, I would love to be able to go surfing with my wife at a local beach. But that’s a really trivial issue compared to the health issues others are facing.”
The challenge of jurisdiction
Shinn provides marine consulting serves to rocket companies designing recovery and reuse systems. Like he said, a weekend of technical research is fun for him. He said he has received positive feedback on the validity of his plan.
However, changing a government project is a laborious slog under normal circumstances. In the case of Tijuana sewage mitigation, both the US and Mexico are involved in a series of projects to treat Tijuana’s sewage and stop the problem.
In the largest of these projects, the US is currently repairing and expanding its South Bay International Wastewater Treatment Plant (SBIWTP) to address the decades-long problem of excess Tijuana sewage flowing into the ocean, causing beach closures, health concerns, and a lingering smell in the South Bay.
Based on that timeline, the SBIWTP will have an expanded capacity by Aug. 27. Ultimately, the plant’s capacity will be expanded even more, to 50 MGD with a 75 MGD peak flow capacity.
The International Boundary and Water Commission (IBWC) said they cannot comment on a proposed plan without having seen the technical specifications and conducting its own technical analysis.
But Frank Fisher, the IBWC’s public affairs chief, said that the expedited expansion of the SBIWTP should help address the problem as quickly as August.
Discharging waste is heavily regulated under the Clean Water Act. The IBWC was in violation of its National Pollutant Discharge Elimination System (NPDES) for an extended period as its South Bay treatment plant failed to process sewage from Tijuana. As construction progressed, the plant returned to compliance in Nov. 2024.
Although the IBWC could not comment on Shinn’s specific proposal, it is reasonable to assume that installing a pipe meant to discharge wastewater into the ocean would fall under the scrutiny of regulation and feasibility studies, extending a potential installation timeline. Of course, wastewater already is being discharged into the ocean — although the government never approved of that discharge either.
An emergency bypass
Shinn said that his goal is to pressure leaders into considering alternative, faster solutions. While he notes that the outfall pipeline would not solve all the problems — it would not provide much relief for those living near the Tijuana River, for example — it could provide relief for SEALs and mitigate health concerns from bacteria in the air in coastal communities.
Shinn said it is an emergency solution to provide immediate relief. Coronado, along with other municipalities in San Diego County, have declared their own local emergencies in the matter.
The problem: A declaration of an emergency is a legal mechanism that governments can use to request funding or seek procedural lenience to expedite repairs of infrastructure. For example, Coronado declared a local emergency after the January 2024 storm that brought flooding to the city. Doing so allowed the city to waive certain requirements in building the Parker Pump Station bypass. The project was completed in days, when it usually would have taken months.
Coronado does not control the infrastructure that contributes to the crisis. The IBWC is a federal entity. California Gov. Gavin Newsom in 2023 declined to declare a state-level emergency, saying the matter was a federal one. There has not been a federal-level emergency declaration, although President Donald Trump commented on the matter in April.
In the meantime, Shinn is trying to get his idea in front of as many people as possible. His petition for the emergency bypass has garnered 366 signatures.
“These are proven technologies which can be installed quickly,” Shinn said. “All it takes is political will. I think the it will come if there’s sufficient public pressure.”
There is a pipe, Parker Shinn. The pipe is what carries the sewage waters and raw sewage from the South Bay Treatment Plant to be dumped into a circular current that flows back to shore at Imperial Beach and on up as far as Coronado.
Ocean scientists testified in 1991 that the proposed location of the South Bay Ocean Outfall (S.B.O.O.) pipe would carry sewage back to our beaches. In the first year of operation of the South Bay Treatment Plant and the S.B.O.O. , the kelp beds near I.B. disappeared. There has been a decline in water and air quality in I.B. and the Tijuana River Valley since then. The South Bay sewage impacts came to be blamed on a sewage-filled beach several miles below the border. Even though the predominant ocean current there is South, not North.
Our present Emergency that now closes our beaches began in 1999. But the slow and simple water quality tests used in the ocean here until May 2022 almost always showed water “safe-to-swim” in the 11 months of dry season. Since Cinco de Mayo 2022 a new water quality test has revealed sewage on our beaches on any day of the year. It depends on the strength of the circular Coronado Littoral Current.
The E.P.A. authorized San Diego County to be first in the nation to use the fast, comprehensive ddPCR water quality test…to identify “cross-border” pollution. Instead the test numbers identify north-of-the border pollution from that 11 foot diameter, 3 mile long underwater pipe, the South Bay ocean Outfall (S.B.O.O.).
See for yourself. Email the County website, sdbeachinfo. Ask for the ddPCR test #s for one day, from the border to the North Island fence. You will see the sewage test numbers are low at the border, make a sharp peak at the IB pier and Cortez, are high at the Navy campus then decrease toward the State Beach and Coronado.
The $ to expand the S.B.T.P. should first connect the plant to the nearest South County pipes that connect to the Point Loma Outfall pipe. Then shut down the South Bay Ocean Outfall. We will be able to swim and surf on our beaches when the U.S. stops the 24 hour ocean dumping of sewage from the South Bay pipe. The S.B.O.O. must go.
Judy Collins
It will never be fixed by design. Too much money involved. The folks charged with solving the problem are immersed in the sewage industrial complex…in other words there is more money to be made in prolonging the problem, on the US side. Ok the Mexico side, they have no incentive to care, so they don’t. They have learned that they can build houses without plumbing with impunity and they can oursource their infrastructure needs to the US tax payer. Not solving it is a win/win for all involved. Mark my words: NEVER. It will NEVER be solved.
Good luck getting the EPA to sign off on this in a timely fashion.
Getting the sewage into the pipe would require building a diversion structure that narrowed the water flow so it could flow into the pipe. If that diversion structure were built further upstream, say just below the sewage plant, that would reduce the Tijuana River problem as well.