San Onofre Beach was closed Friday after officials said a blockage caused thousands of gallons of sewage to spill into the water on Thursday.
An estimated 7,000 gallons made its way into waters at the San Onofre Plant at 5000 Pacific Coast Highway, starting at about 9 a.m., according to a media release.
An initial estimate said as much as 26,000 gallons may have wasted, officials reported.
Officials blame the spill on a blockage in the line which resulted in an accidental bypass of sewage to the outfall that discharges 3000 feet out from the shore line.
The spill didn't end until 4 p.m. and maintenance crews were able to clear the blockage shortly before 10 p.m., officials said.
Contamination signs were posted from 1/4 mile north and 1/4 south of the San Onofre State Beach and are expected to remain there until samples confirm the water is safe.