KEY POINTS:
Close to a million litres of sewage was dumped into the Whangarei Harbour on Sunday - the third spill this year.
The 845cu m discharge lasted about three hours and was caused by Okara Park Pumping Station overflowing in the heavy rain as stormwater overwhelmed the system.
Signs warning people against swimming for one week and collecting shellfish for a month have been put up in affected areas around Whangarei's upper harbour, upstream of the Onerahi boat ramp.
