Work is continuing to repair a damaged wastewater pipe belonging to Pan Pac Forest Products.
In September, a resident reported discolouration near the water's edge at Whirinaki Beach.
It was found to be seepage of treated wastewater from the Pan Pac's wastewater treatment plant.
This year, the discharge pipeline was extended from 300 metres to 2.4km.
"Since discovering the pipeline crack we have taken guidance and advice of Niwa scientists and we have been conducting weekly testing at multiple locations along the beach to ensure a minimum of 50:1 dilution is occurring outside of the working site," a Pan Pac spokesperson said.