A section of Seal Beach reopened Wednesday afternoon after closing because sewage spilled into the San Gabriel River Saturday afternoon.
"The pump station lost power ... so the sewage started back up, and it overflowed the system, went down the gutter across a parking lot, and then into Coyote Creek," said Orange County Environmental Health water quality program manager Anthony Martinez.
The spill was caused by a loss of power at a sewage pump station near Behringer Park in La Mirada, Martinez said. The pump station is at a low point where sewage has to be pumped up a hill.
About 3,000 gallons spilled, but L.A. County Public Works managed to recover about half of it before it reached Coyote Creek.
"So it's a big spill, but it's not huge, by regular standards," Martinez said. "I mean, it's big enough to close the beach, but it's not a massive spill."
To reopen the beach, officials needed two consecutive days of acceptable water sample results. They had one day of clean results Tuesday, but still needed that second day, according to Martinez.
"Sewage spills occur every so often. There might be one every couple of weeks," Martinez said. "For the most part, they're contained on private property; rarely do they manage to get into the waterways and make it to the ocean."
The cause of the outage is unknown, but could have been caused by either an equipment failure or a loss of power in the area, Martinez said. The pump itself was operational by the end of Saturday afternoon.
You can get the latest details about beach closures in Orange County at OCBeachInfo.com.
Correction: An earlier version of this story incorrectly listed Anthony Martinez's job title. KPCC regrets the error.
This story has been updated.