A large sewage spill into the Los Angeles River has forced the closure of several L.A. County beaches on Wednesday.

The spill occurred in San Gabriel where around 15,000 gallons of sewage spilled into Rubio Wash which leads to the L.A. River. 

A grease blockage in the city sewer main line caused the spill, according to Long Beach city officials.

While the origin of the spill is 25 miles away, officials said the sewage will eventually arrive in Long Beach, contaminating over six miles of public beach areas.

All swimming areas west of Belmont Shore are closed to the public at this time.

“Water from the Los Angeles River connects to the Pacific Ocean in Long Beach, which means pollution anywhere upriver can affect the coastal waters and other waterways in the city,” officials explained.

The city’s health inspection team will monitor water quality along the affected beach sites. The swimming areas will remain closed until results meet the state’s safe water quality standards.

A rain advisory issued Wednesday morning is also in place for all beaches. People are advised to avoid swimming in ocean waters for at least three days following any significant rainfall. 

City workers have begun posting signs along the waterfront to let beachgoers know of the closure. 

“To protect the safety of the public, water samples are collected and tested routinely to monitor bacterial levels,” city officials explained.

The most up-to-date information about the closure can be found by calling 562-570-4199 or visiting longbeach.gov/beachwaterquality.