Two popular Victorian beaches are off limits this weekend as the Environment Protection Authority (EPA) investigates separate sewage spills.

A pump failure at a camp near Portsea's Front Beach caused an overflow of raw sewage yesterday, while an underground leak at Black Rock's Half Moon Bay on Thursday is still causing problems.

The EPA's Leigh Bryant says they will be testing the beaches daily and people should monitor conditions.

"If people are looking to swim in that area, keep an eye on the... EPA website, because that's our best mode of communication with the community as to what the condition of those beaches is like," he said.

"[Warnings] will stay in place until we have test results showing that those bacterial levels have returned to a level where the organisation is comfortable in saying that's OK to swim in that area."