A portion of the ocean around the Balboa Pier in Newport Beach is closed to swimmers after 300 gallons of raw sewage leaked from a pumping tank below the pier into the water Wednesday.

The Orange County Health Care Agency said the water 1,000 feet upcoast and 1,000 feet downcoast of the pier will be closed until at least Saturday or until water-quality tests meet acceptable levels of bacteria under state standards.

The cause of Wednesday’s leak was unclear.

For more information, call (714) 433-6400 or visit ocbeachinfo.com.

hannah.fry@latimes.com

Twitter: @HannahFryTCN