SAN DIEGO (Border Report) — Earlier this month, and seemingly overnight, the stench of raw sewage permeated the air along the border between San Diego and Tijuana.

It went on for days.

It was the result of yet another massive spill that sent millions and millions of gallons of untreated raw sewage from Mexico into the Tijuana River Valley just inside U.S. territory.

According to a report from the International Boundary and Water Commission, the flow began on Jan. 7.

On Jan. 9 alone, an estimated 13 million gallons of raw sewage made their way into the Tijuana River Valley; the next day another 17 million.

The spill went uncontrolled for days, officials say.

Stewart’s Drain along the border between San Diego and Tijuana. (Salvador Rivera/border Report)

The IBWC concluded that a deteriorated sewage pipe along the border known as the “international collector” ruptured, sending effluent through Stewart’s Drain, located at the base of a small portion of the border barrier, just to the east of a wastewater treatment plant.

Crews at this facility, which usually handles 25 million gallons of raw sewage from Mexico daily, initially detected the problem.

They noticed only about half of the normal untreated material was coming in from Mexico and determined the rest was spilling onto the Tijuana River Valley.

“Engineers from both Sections of the Commission are working together to address this sanitation emergency,” said IBWC U.S. Commissioner Maria-Elena Giner. “I commend them for implementing some short term measures while we come up with a plan for a longer-term solution.”

For a time, there was fear that some of the lines north of the border were clogged adding to the problem, but after an inspection, it was determined they were not obstructed.

It appears the problem has been fixed.

The Environmental Protection Agency has pledged millions of dollars to help fix the sewage problem that has plagued the area for decades.

“In order to protect public health and vital ecosystems in this vibrant area, we need a bold solution to the transboundary water pollution challenge,” Radhika Fox, the EPA Assistant Administrator for Water, said back in November. “We’re announcing our intent to pursue a holistic water infrastructure strategy to address multiple facets of this challenge and make real progress for the future of the San Diego region.”

The projects to be financed by the EPA are still years away.

When spills have taken place in the past, the sewage that reached the Tijuana River Valley made its way to the ocean, forcing the closure of beaches in cities such as Imperial Beach and Coronado, California.

Such was the case with the spill earlier this month.