Improvements at the international wastewater treatment plant in San Ysidro and new projects are expected to help the transboundary sewage crisis from Tijuana by the end of this year.
That was the message on Nov. 8, when the United States Section of the International Boundary and Water Commission (USIBWC) hosted a second Citizens Forum at the Winn Room inside the Coronado Public Library.
The more than 50 attendees first heard from David Sodeman, chief of monitoring and technical services division at the San Diego County Air Pollution Control District, about air monitoring taking place in San Ysidro to gather data related to the Tijuana River odors.
The district’s mission is to provide clear air by working with local, state, and federal agencies, said Sodeman.
Six sensors installed
He said there have been six AQMesh sensors installed near the Tijuana River Valley that will soon be rolled out to the surrounding communities.
Soderman said a 2017 state law is helping areas identified as disadvantaged communities, including areas east of San Diego Bay, to participate in the Community Air Protection Program.
“This program ultimately led to us deploying sensors to monitor for hydrogen sulfide, which is the main compound that causes the odor…that kind of rotten egg smell,” said Sodeman.
After gathering input from local residents of affected areas, including the international border community, they created a Community Air Monitoring Plan (CAMP) and Community Emissions Reduction Program (CERP), which fall under the main program umbrella.
Sensors to gather numerous data points
The sensors, funded by a federal grant, are solar-powered which allows hourly data transmission through a cellular network. The devices are intended to gather the following data: hydrogen sulfide; sulfur dioxide; total volatile organic compounds; carbon monoxide; nitrogen dioxide; wind speed and direction; temperature, pressure, and humidity. Sensors are also capable of measuring levels below the hydrogen sulfide odor limit (10 ppb).
For now, all the sensors can be found at San Diego Fire Station 29, 198 W. San Ysidro Blvd., and Sodeman said they will be deployed to other monitoring locations including Imperial Beach City Hall, Tijuana River Valley Estuary, and residential areas near San Ysidro, South San Diego and the Tijuana River Valley.
Data shows high odor levels
So far, the collected data in San Ysidro show levels reaching 45 Hourly Hydrogen Sulfide Concentration (ppb), above the OSHA Odor Threshold, of 10 ppb, and CARB Air Quality Standard, 30 ppb, since late September.
Apart from deploying the sensors to other locations, next steps are to share data with the public via the website sdapcd.org and to collaborate with other agencies to continue addressing the ongoing odor issues in the area, added Sodeman.
What about Coronado?
USIBWC Board Member and Coronado City Councilman John Duncan expressed an interest in considering this technology at locations closer to the ocean in Coronado and Imperial Beach.
“Most people agree the disadvantaged communities that have been suffering need resources,” Duncan said. “But pollution doesn’t know economic boundaries.”
Working on federal compliance
In a second presentation, the IBWC shared that its still working to achieve compliance with federal standards and prevent future problems of system capacity and exceedances.
The commission’s Operations Department Principal Engineer Isela Canava then gave updates on the South Bay International Wastewater Treatment Plant and other San Diego–Tijuana wastewater infrastructure improvement projects in the works.
During her presentation, Canava reported that the dry weather should decrease some transboundary flows into the United States starting in November.
Project completion expected this month
She also said ruptured pipelines in the Tijuana sanitation system have caused significant higher flows throughout 2023 that exceed the treatment plant’s capacity of handling an average of 25 million gallons a day of sewage from Tijuana.
Canava said Mexico’s repairs to pipeline PB1A in Tijuana, which ruptured in July 2022, has an estimated completion of Nov. 2023. That fix is expected to help reduce transboundary flows and excess flows to the plant.
To reach federal compliance of handling the waste from Tijuana by Aug. 15, 2024, the IBWC has planned for a list of incremental improvements including replacing inoperable Junction Box 1, to restore flow control into the plant, using $5.8 million of the $10 million in federal funding, which should reach completion by early 2025.
Setbacks from Tropical Storm Hilary
However, Tropical Storm Hilary in mid-August halted the rehabilitation and expansion of the South Bay International Wastewater Treatment plant and now repairs and compliance with federal mandates must occur at the same time, said Canava.
The Tropical Storm Hilary Recovery Plan is lengthy and includes installing two pumps previously ordered that should arrive in November or next month, she said.
“We are self-reporting all the permit violations, we realigned $18 million to address the work due to the excess flows and the Tropical Storm Hillary impacts,” said Canava.
Cavana added there are regular meetings with the San Diego Regional Water Quality Board and Mexican officials on the projects.
As for Mexico’s project status on Minute 328, a binational agreement between the United States and Mexico, Canava said repairs for the San Antonio de los Buenos Wastewater Treatment Plant will go out to bid in late 2023.
Locals speak out
Throughout public comment, multiple individuals conveyed frustrations and made suggestions to help with the wastewater issue stemming from Mexico.
Considerations ranged and included drastic measures such as annexing the southern country to enforce their adherence to U.S. laws and regulations.
One board member and Imperial Beach resident Leon Benham proposed the creation of a local water district controlled by the community to manage the problem. And overall, speakers emphasized the need for urgent action to prevent further environmental damage and health risks.
Among discussion of future agenda items was a visit to the Orange County Water District to learn from its Groundwater Replenishment System operations and a presentation by Board Member Oscar Alberto Pombo on his research about the Tijuana water system.
According to the IBWC, Citizens Forum meetings are held every four months. The next one is expected in the first quarter of 2024, said Public Affairs Officer Frank Fisher.