An investigation is under way to discover why sewage was discharged into the sea off New Plymouth with less chlorine in it than usual.
The treated wastewater, released 400 metres offshore, was still disinfected but New Plymouth District Council's water boss Mark Hall said warning signs were put up as precaution.
The cause of the low dose of chlorine, which occurred over 45 minutes at the New Plymouth Wastewater Treatment Plant last week, is being investigated with a report due within a week.
Yesterday, "no swimming" signs were removed but it was still too dangerous to gather shellfish from the area.
Mr Hall said the keep-clear sign, which also barred swimming at the beach, should have been removed last Saturday. Instead it was taken away yesterday after a report in the Taranaki Daily News.
Mr Hall said the council was discussing adding dates to the signs so the public would know how long the warnings were in place for.
The sign warning people to stay away from shellfish must stay out for four weeks, as shellfish can accumulate any viruses in the water.
It will be removed on March 12.
- Taranaki Daily News
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