This article is written with the intent to educate and inform the public about what is presently known about cross-border pollution from Mexico. Citizens for Coastal Conservancy (C4CC) of Imperial Beach is a non-profit whose main mission is to educate the public about sources of coastal sewage pollution and provide insights of the latest technology which can solve this chronic public health problem permanently.
Here are some known facts: There are only two sources of ocean pollution at our border.
The first source of water pollution is the Tijuana River (river mouth) one mile south of Imperial Beach. This river is normally dry for 11 months out of the year. However, because of a pipe break in Mexico, since August of 2022, the river has been constantly flowing with sewage at a rate of 40 million gallons per day (MGD) to 80 MGD.
The natural water table is near the surface so the water cannot percolate into groundwater, instead it sits above the ground creating stagnant sewage ponds. With no wind at night, the smell of sewage is overwhelming.
The second source of ocean water pollution is the 12-foot diameter sewage discharge pipe 90 feet deep below the ocean surface and 3 miles off the coast of Imperial Beach known as City of San Diego Ocean Outfall (SBOO).
Scripps Institute studies from 1976 and water quality testing over the last 20 years conclusively prove this treated sewage water travels to the coastline of Imperial Beach and up to Coronado between 88% to 100% of the time. Monitoring water testing results show that this treated water flow from the SBOO is a major factor in beach closures.
Testing the water: Old and new methods
In May of 2022, San Diego became the first county in the entire United States to adopt DNA based water testing method. However, for approximately a year after, both the old MPN test and the new ddPCR test methods were used. The testing results, for the same sample locations, show two different outcomes.
The old MPN test, which tests for living infectious disease which will make you sick, keeps the beach open and the DNA test method, which tests for dead infectious disease which will not make you sick, keeps the beaches closed. See the test results for two locations. End of Seacoast Drive, Imperial Beach and Carnation Ave, Imperial Beach.
What is clear from the water testing data above is one test is subjective and one is objective because the MPN tests for the exact actual living infectious diseases and the ddPCR does not.
Additionally, there is no consideration that the SBOO outfall, upstream of the beach by 3 miles, which pumps out 1.25 million gallons a day of fecal DNA solids. This of course would have a huge effect on the high ddPCR testing results. But think about that: Is that not what fecal solids exactly contain?
Fecal solids are ladened with human intestinal DNA. As ironic as this sounds, the SBOO testing monitoring program does not use ddPCR testing, rather the City of San Diego uses the old MPN test which, allows the treated sewage dumpsite to remain open. Many people now want the discharges from the SBOO and San Diego Treatment plants to be tested using the ddPCR testing methods.
Common misconceptions
Here are some common misconceptions about other sources of ocean pollution:
The myth and suspect EPA theory of sewage, coming north from Mexico in the surf zone from a discharge point 10 miles south of Imperial Beach known as San Antonio de Las Buenos (SAB), is inaccurate. The water testing shows this narrative is a mischaracterization of the known science.
Twenty or more years of extensive coastal water monitoring testing and past studies, conducted by Scripps Institute, have conclusively proven that SAB is not a major source of coastal contamination for beaches in the United States. Here is some background:
- Scripps Institute data shows northern flows of ocean water from SAB only occur 12% of the year in the top 30 foot of the thermocline. For a large majority of the year, these flows do not occur but rather, the ocean flows south 88% of the time. Scientists conducting the SBOO monitoring studies in 2004 and 2019 clearly state that the northern flow of sewage from SAB did not warrant consideration, as northern currents from SAB were deemed unlikely to occur and insignificant.
- When these north bound do occur, actual surf zone water testing shows that by the time the water reaches the bullring border fence, most of the pollution has dissipated and has been consumed by wave action and natural biological processes in the surf zone.
- Many have questioned why the EPA recently started pushing this false narrative in October of 2021, ignoring 40 years of Scripps studies and water testing data which proved water flows to the south and almost never comes north from SAB. To many, this unproven hypothetical theory of north bound water travel seems suspect and is an intentionally false narrative. Also, many ask why the EPA would place this unproven theory as the cornerstone of the EPA USMCA plan to justifying bringing 480% more Mexican sewage to be dumped directly into the path of the Coronado Littoral Cell.
Coronado Littoral cell
The counterclockwise Littoral Deep Ocean currents off Imperial Beach is in process 100% of the year. The City of San Diego’s 12-foot diameter SBOO sewage pipe, installed in 1997, lies in the direct path of this onshore flow and brings the processed sewage water directly to the beach and then runs north. Water Testing proves this without exception during normal weather.
At the time of planning the SBOO in the 1980s by the City of San Diego, no less than three of the top Scripps Institute scientists predicted our beach would be constantly polluted. This prediction, a hypothesis at the time, has proven over time to come true.
We know that since 1997 our large coastal kelp beds off Imperial Beach are now gone. The north and south rock jetties in Imperial Beach, which used to have abundant and lush tide pools, are now gone as if they have been scrubbed clean by chemical bleaching. This is an indicator of the health of our coastal environment. To dump more sewage off Imperial Beach is unacceptable and we ask the EPA and our local public officials to justify this plan in detail.
From the above knowledge we have gained over years of observation, let’s summarize the understanding we now have about ocean water pollution:
- The sources of ocean water pollution are the Tijuana River and the SBOO.
- These pollution sources feed into an ocean current known as the Coronado Littoral Cell.
- The Coronado Littoral cell travels in the surf zone along Imperial Beach and north to Coronado.
- If our government would use the same ddPCR to test the treated sewage effluent discharge, dumping additional sewage through the SBOO would be infeasible and illegal.
- The SB507/USMCA Comprehensive plan, authored by United States EPA, proposes to dump 480% more treated sewage water off Imperial Beach. Presently, each day this treated water contains 1.25 million gallons of fecal sludge. This, plus the proposed increase in water volume, will total 6 million gallons a day of fecal sludge to our coastal environment.
It is clear from our understanding that we cannot proceed with the SB507 USMCA Comprehensive Plan, as it will be another failure to our coastal environment, and we will never have the outcome we are now paying hundreds of millions of our taxes on. It will be a failure for us, our children and future generations.
Leon Benham, the C4CC president, and has been a member the IBWC (International Boundary and Water Commission) Citizens Advisory Board for one year. He has worked for more than ten years on environmental projects in the San Diego Bay, Otay River Valley and the Tijuana River Valley.
Editor’s note: The Coronado News welcomes guest columns. If you have previously submitted an op-ed or are interested in submitting one, contact sofie@thecoronadonews.com.
