Wastewater has leaked at the popular Wellington surf beach of Lyall Bay.
According to Wellington Water, a network fault caused the leak at the airport end of the bay.
It's the second such incident this year.
A sewage spill on February 3 forced beaches in the Wellington region to close for two days.
Surfbreak Protection Society spokesman Michael Gunson said these leaks are happening too often.
"I think it's entirely inappropriate.
"Back in 2010 I submitted against the wastewater treatment upgrades because I thought that they were not giving enough priority to the problem.
"But we've still got the ongoing problem. Once is bad enough, but it's still happening fairly regularly.
"I don't think they take it seriously."
Gunson said the wastewater system needed more investment, but also a change in attitude to take the problem seriously.
The leak's now been stopped, with clean-up crews disinfecting the area and leaving up warning signs for the next few days.
Greater Wellington Regional Council is investigating the "unauthorised discharge of wastewater".
A spokesman said the incident had been caused by waste leaking from a pipe, and into an adjacent storm drain.
That drain flowed directly across the road to the beach, where it soaked into the sand.
It's believed the waste had not reached the tide line.
Wellington Water is testing the site to ensure any contamination is contained.
Greater Wellington Regional Council is also testing the site, with results available to the public on Wednesday.
A spokesman for Regional Public Health said they weren't issuing a public safety notice at this time, as it was believed the leak was dealt with quickly enough.
At this time locals aren't being told to stay out of the water.