By Sandra Dibble
and Mike Lee
Originally published January 18, 2011 at 3:06 p.m., updated January 18, 2011 at 8:44 p.m.
An estimated 1.3 million gallons a day of sewage are flowing into the ocean just south of the international border, in what will rank among the largest single incidents to affect San Diego County in the past decade.
The ongoing leak adds a potent pollutant to coastal waters that currents commonly push north into the United States, where they mix with contaminated flow from the Tijuana River, which has lead to beach closures in South County for the past month.
Estimates of the spill size vary greatly — from more than 30 million gallons by environmentalists to just a few million gallons by wastewater officials in Mexico. Either way, the situation provides a vivid reminder that despite numerous upgrades to the sewage system in Tijuana, it remains a chronic environmental and human health problem with roots going back more than 70 years.
Baja California’s top health authority on Tuesday closed the beaches near the leak at Playas de Tijuana as a precautionary measure. Surfers in South San Diego County said they were concerned about getting sick from the tainted water.
The break was about one mile south of the border in a pipe linked to a pump station that lifts sewage to the Punta Bandera treatment plant. The state’s health department said a pipe ruptured when the ground gave way after December’s rainstorms.
A central question is when the leak started. Baja wastewater officials said Tuesday the major problems started last weekend and they acted as quickly as possible to a situation that started small and blew up without warning.
Environmentalists in Mexico said major flows began before Christmas. They and their counterparts in the United States questioned whether Mexico acted fast enough to address the break and issue warnings.
“This is pretty serious and demonstrates a breakdown in communication” between Mexican and U.S. officials, said Serge Dedina, head of the environmental group Wildcoast in Imperial Beach. “This is precisely an issue we have been trying to deal with — just getting basic notifications on sewage spills in Tijuana. Authorities have placed thousands of people at risk.”
Officials initially believed the problem was an overflow that typically occurs during rainstorms when sewage and stormwater mix in overloaded pipes, said Agustin Rojas, spokesman for the CESPT, the acronym of the state public service commission of Tijuana.
He said the scope of the issue was not initially apparent because it involved an underground sinkhole that formed around Dec. 29 but did not immediately damage the 30-inch pipe.
“We believe it began to have problems, but the water wasn’t flowing to the ocean yet,” Rojas said.
On Sunday, he said, “We had not detected the magnitude of the problem. ... It wasn’t until Monday.”
He said it would take another couple of days to stop the flow. The repairs involve replacing a 250-foot portion of the collector pipe that’s buried 15 feet below ground.
“We’ve got crews working long-hour shifts. It’s not an easy job, but they are committed to the task.”
Margarita Diaz, head of Probea, a Playas de Tijuana-based environmental organization, said the problems date back to Dec. 23.
“The collector was damaged, the ground collapsed, and it folded, and plugged it up. This caused the sewage to flow north toward the manholes. As it could not go to the pump station, it flowed through the drains.”
Diaz said the issue of the sewage overflows reached her office at the beginning of January, when local residents called and complained. When she called the CESPT, she said the common response was that the engineer was on vacation.
The Playas beach was closed Tuesday afternoon. “But this should have happened a long time ago,” she said. “It should have happened immediately, from the moment that the spill was detected. They were three weeks late.”
Mark McPherson, chief of land and water quality for San Diego County’s environmental health agency, said Tuesday afternoon that he had received no official notice of the incident. In this case, he said an alert would not have made a major difference because the Tijuana River is still flowing with millions of gallons a day of sewage-tainted water and the county has maintained beach closures for weeks in the South Bay because of that.
Dedina at Wildcoast said the problems at Playas de Tijuana likely are contributing to the mess caused by the Tijuana River.
“The stench at the south end of IB this morning was overpowering,” he said.
Conditions were worse south of the international border.
“I have been watching and smelling a stream of untreated sewage run down the street next to my house in Playas de Tijuana and to the ocean in a constant flow,” said resident Scott S. Peters. “The authorities have simply removed the manhole covers on my street and have been letting the sewage flow like a river since the storm a few weeks ago.”
Wastewater has been a major source of tension along the border since the early 1900s because Tijuana’s sewage system has not kept up with growth. Raw sewage flows into the Tijuana River whenever it rains. Agencies on both sides of the border have made big strides to cut down the pollution by building treatment plants and other facilities.