Aliso Beach on the south Orange County coast was closed Friday after 900,000 gallons of raw sewage spilled into Aliso Creek, which drains into the ocean in the city of Laguna Beach.
The sewage came from a pipe that ruptured Thursday in Aliso Park, officials said Friday. The spill is the third sewage contamination of Aliso Creek this year, according to Orange County health authorities. The previous two spills also were from broken sewer mains.
Friday's spill also closed beach areas north to Treasure Island and south to Table Rock.
"I think Aliso Beach will probably be closed for a week, but we certainly hope to have it open again for the Fourth of July weekend," said Michael Wehner, chief of the Orange County Health Care Agency's water quality program.
Wehner said the adjacent beach areas--Treasure Island and Table Rock--may be opened sooner because they are not as close to Aliso Creek. The creek flows into the ocean at Aliso Beach, just north of the Aliso Pier.
Wehner said strong surf conditions in recent days may help reduce health dangers from the spill "because more oxygen will get to the bacteria" left by the sewage.
"We won't have preliminary testing information until Monday," Wehner said.
Michael Dunbar, assistant general manager and chief engineer for the South Coast Water District, said the sewer break was discovered about 9 a.m. Thursday in Aliso Park.
The park is a small, grassy recreation area on the north side of Pacific Coast Highway, opposite Aliso Beach. The park is bordered on the west by Aliso Creek, and there is a footpath under the Pacific Coast Highway bridge that connects the park and Aliso Beach.
Dunbar said that before the broken sewer could be capped, about 900,000 gallons of sewage spilled into the park and flowed into nearby Aliso Creek. The sewage then flowed down the creek to Aliso Beach, which is bisected by the mouth of the creek.
Dunbar said the apparent cause of the spill was "an older pipeline that gave way."