After being cited by the San Diego Air Pollution Control District for causing sewage odors that vex South Bay communities, the U.S. International Boundary and Water Commission (IBWC) says it has not violated air pollution laws.
But the district has rejected the federal agency’s response and is considering seeking an abatement order, which could order the IBWC to take specific actions or refrain from particular ones.
In late July, the district had issued a notice of violation to the IBWC, alleging that it caused a public nuisance after a June malfunction of its pump station on Hollister Street in the Tijuana River Valley. That led to a five-hour spill of about 302,000 gallons of untreated wastewater.
District officials said they responded to about 1,000 odor complaints from people around the Tijuana River during a period when the IBWC’s pump station was inoperative.
The federal agency manages infrastructure that’s suppose to treat a certain amount of Tijuana sewage coming over the border. Years of negligence and underinvestment in treatment plants from both countries have resulted in millions of gallons of partially treated sewage water to flow daily through the Tijuana River and Pacific Ocean.
But the IBWC says its efforts to repair infrastructure north of the border are severely compromised by unprecedented volumes of wastewater and sediment flowing from a highway construction project in Tijuana that has no mitigation control.
According to data the IBWC released Thursday, the federal agency has hauled 8,294 tons of sediment and trash from its treatment plant, nearly 10 times more than in 2023.
“This sediment overwhelmed Hollister Pump Station, ultimately leading to its failure,” Morgan Rogers, the IBWC’s San Diego operations manager, wrote to the district on Aug. 12.
The pump station’s failure was not due to inadequate maintenance, he added, as air pollution officers had argued in its July notice. Rogers said the IBWC had already invested in upgrades to the Hollister facility after it was left damaged by Tropical Storm Hilary last year.
It also “immediately took corrective action” following the June pump station malfunction. The agency shut down canyon collectors to prevent more wastewater flows to reach the Hollister pump station, cleaned the facility, ordered new parts to repair broken ones and removed as much of the spill as possible.
Rogers also argued that the pump station has an odor treatment system that worked even during the malfunction.
The sewage flows causing odors stem from the Tijuana River, he added, not the pump station that the district regulates.
“USIBWC infrastructure is not discharging or emitting odor, nor is it causing or contributing to the odor emanating from Mexico’s flows,” Rogers said. “Thus, the permit limitations do not apply to USIBWC with regard to these flows.”
In an Aug. 19 response to Rogers, the District’s Deputy Director Mahiany Luther concurred that the source of the odors is Tijuana River flows. But argued that the public nuisance documented “is primarily due to a combination of outdated infrastructure and inadequate maintenance, both of which fall under the responsibility of the USIBWC.”
“In fact, USIBWC representatives reported to District staff that the existing Hollister surge tank has been operating five years beyond its expected lifespan,” she added. “Additionally, maintenance records provided by USIBWC indicate that proper maintenance has not been conducted.”
The district argues that if treatment infrastructure, including the pump station, were fully operational, “even at current capacity, the odor nuisances would be significantly reduced.”
Luther said if the IBWC does not take immediate action to prevent further discharges of pollution into the Tijuana River Valley, the district would seek an order of abatement from the district hearing board.
Hollister pump station is expected to resume operations next month, the federal agency said.
Luther proposed in her letter meeting with the IBWC first. On Thursday, an IBWC spokesperson said the federal agency had yet to respond.
Commissioner Maria-Elena Giner, who heads the USIBWC, said the agency is working with its Mexican counterpart to identify sources of sediment coming from Tijuana.
“Getting the water off the river is like our number one priority right now,” she said. “Right now, there should be zero water in the river, and that’s what is affecting beaches. That is what is affecting the smell in the area.”
