A massive sewage spill in Tijuana that polluted beaches in San Diego County last month may have been no accident, according to state and local officials.
In a preliminary estimate, officials said about 143 million gallons of raw sewage spewed into the Tijuana River during a period of more than two weeks that ended Thursday. While cross-border sewage spills of a few million gallons are routine for the region, this is one of the largest such events in the last two decades, according to water quality experts in San Diego.
People from Tijuana to as far north as Coronado have been complaining of foul odors for weeks, prompting lawmakers in San Diego County to contact federal regulators as well as agencies in Mexico.
The U.S. regulators said their Mexican counterparts have given little explanation. Mexican officials also haven't responded to requests for comment for this article since Monday.
"This was like a tsunami of sewage spills," said Imperial Beach Mayor Serge Dedina, who said he tried to get answers from officials on both sides of the border for more than a week, with no response.
"What's worse is it looks to me like this was deliberate," he added. "It saves [the Mexican agencies] a lot of money in pumping costs, and ultimately, they can get away with it and do it all the time, just on a much smaller scale."
The toxic discharge is estimated to have happened from Feb. 6 through Thursday, while repairs were made to a major sewer pipe near the confluence of Mexico's Alamar and Tijuana rivers, according to the U.S. side of the International Boundary and Water Commission. Baja California's State Public Service Commission maintains the sewer system infrastructure in that area.
"They basically said it was a bypass of raw sewage into the Tijuana River during the rehabilitation of a large sewer pipeline in Tijuana," said Lori Kuczmanski, spokeswoman for the U.S. side of the commission, which oversees international water treaties with Mexico, among other things.
The commission announced the spill on Friday. Before that day, officials in Mexico had not responded to multiple inquiries about the incident, according to local, regional and federal regulators in the United States. By Tuesday, U.S. officials said, their Mexican counterparts still offered only scant details of the situation.
They also said Mexico didn't give them advance notice of the sewer-pipe repair project.
"Was the spill intentional? Well, yeah," said Dave Gibson, executive officer of the San Diego Regional Water Quality Control Board. "It appears they were working on the pipeline. I don't believe that it was a question of it failing.
"At least a notification would be a good neighborly thing to do, to let us know what was coming down the river before it got here so we could alert the public," he added.
A similar project in the United States would include efforts to prevent sewage from flowing downstream by using booms and then pumping the diverted sewage back into the wastewater system, Gibson said.
Emerson writes for the San Diego Union-Tribune.