Aug. 28 marked 100 days since the International Boundary and Water Commission (IBWC) and the Environmental Protection Agency (EPA) announced a fast-tracked expansion of the South Bay International Wastewater Treatment Plant, and the binational agency said on Aug. 27 that it intends to test the project’s completion instantly.
On May 20, the two agencies launched a plan to increase the treatment of sewage flows at the South Bay plant by 10 million gallons per day (mgd) in 100 days, increasing the plant’s capacity from 25 mgd to 35 mgd.
This project was originally estimated to be completed in two years, but the presidential administration accelerated the project to be completed in just 100 days – by Aug. 28.
The day prior to that time marker expiring, the IBWC confirmed at a San Diego Regional Water Quality Control Board meeting that it would finish the 100-day fast track plan as scheduled, and begin increasing capacity by five mgd.
According to Principal Engineer Ramon Macias of the IBWC, it is expected the full 10 mgd will be tested in two-to-five weeks.
What we want to do is make sure that we start the process and incrementally start getting the flows in so that we can fine-tune the system and make sure what we’re predicting is actually happening.
IBWC Principal Engineer Ramon Macias
“What we want to do is make sure that we start the process and incrementally start getting the flows in so that we can fine-tune the system and make sure what we’re predicting is actually happening,” Macias explained.
This project was in partnership with the U.S. EPA, whose administrator, Lee Zeldin, commented saying that the Trump administration was committed to delivering a permanent 100% solution to the people affected by this crisis, and “that’s exactly what they’re going to get.”
“Just four months after I personally surveyed the environmental devastation in San Diego, seeing the polluted waterways, closed beaches and smelling the foul air, we’ve delivered this critical expansion years ahead of schedule,” Zeldin said in a statement. “Protecting human health and the environment is our first priority at EPA, and no American should have to worry if the air they breathe or the beaches they visit are safe.”
Also at the Aug. 27 meeting, the Water Quality Control board accepted a revised cease-and-desist order on the IBWC, which functions as a legal permit allowing the treatment plant to process the extra 10 mgd.
The order is necessary in the absence of an amended National Pollutant Discharge Eliminations System permit, and it will allow for the accelerated expansion as long as the IBWC meets requirements and schedules.
The water boards are not in the tradition of permitting things that are not up to the standards the state of California embraces.
Celeste Cantu, chair of the San Diego Regional Water Quality Control Board
“The water boards are not in the tradition of permitting things that are not up to the standards the state of California embraces,” said Celeste Cantu, chair of the Water Quality Control board.
With accepting the revised cease-and-desist, the boundary commission must comply with effluent limitations, remedial actions and preventative actions listed in the order, such as updating and implementing protocols with Mexico in order to make sure the average monthly effluent flow rate doesn’t exceed 35 mgd.
This follows a memorandum of understanding that was signed between Mexico and the United States at the end of July, signaling both countries’ agreement to complete all sewage related projects by the end of 2027. Mexico also agreed to enter into a new minute order with the United States by the end of the year.
“I think this is a major agreement,” Mayor John Duncan said during a Coronado City Council meeting on Aug. 19. “I’m very happy that it has happened. I’m impressed by it.”
Council member Mark Fleming reported on Aug. 19 that the South Bay plant was receiving around 24.8 mgd of flow, which is just under the previous treatment capacity of 25 mgd. Council member Amy Steward noted that this is the dry season, so flows aren’t as high.
With the increased 10 mgd added to the SBIWTP, it should account for some of the increased flows that will come in during the rainy season.
However, although recently rehabilitated, there is still 27 mgd of untreated effluent seeping into the Pacific Ocean from the Mexican treatment plant at San Antonio de los Buenos (SAB), Fleming said. The updated plant is equipped to treat 18 mgd of sewage.
There is also 5 mgd of flow going through the Tijuana River, which means there is a total of 75 mgd of sewage circulating through all sewage infrastructure – 24.8 mgd at the SBIWTP, 45 mgd through SAB and 5 mgd at the river.
It is estimated that half of the flow at the river is sewage.
