Pan Pac is searching for an alternative solution to fix its broken wastewater pipe after a third attempt has failed.
It comes six months after a resident first reported discolouration near the water's edge at Whirinaki Beach, which was found to be seepage of treated wastewater from Pan Pac's wastewater treatment plant.
In a letter sent to residents on Thursday, the mill's managing director, Doug Ducker, said the company plans to use an alternative method of pipeline repair using a rigid pipe insert rather than the fibreglass patches and Swiss liner considered earlier.
"Further pipe cleaning and inspections have determined additional failures due to corrosion evident on the bottom of the existing pipe," Ducker said.
"The nature of this damage would likely pose risks to the integrity of the fibreglass patch and liner solutions that we have been working toward over recent weeks."
He said the alternative repair method allows them to insert a new, rigid pipe into the original pipe and join on to the 2017 pipeline extension.
"This solution will reach over 300m from the beach and so protect against further deterioration of the older steel/concrete piping."
Work is expected to resume following the Easter/Anzac period, with boat activity near the offshore access point as the existing pipe is prepared for the rigid pipe insert.
On the beach, a series of wooden beams will be placed within the worksite to support heavy equipment to be used during the pipe installation.
This will be followed by a full clean of the internals, a final video inspection to ensure any obstruction has been cleared and then the new polyethylene insert will be fitted.
Ducker anticipates the work to be completed by mid-May but says that the completion date is subject to sea conditions.
While they progress with this repair, a "long-term replacement solution continues to be investigated".
Resident Glen Kohlis, who first reported the leak, continues to see "foam and brown stuff" on the beach.
"It doesn't give you much confidence. You would have thought that when they put it out, they would have some idea of how to fix it if it broke."
He says there is no option but to fix the pipe. "They can't keep pumping stuff on to the beach like that. It is disgusting."
Last month, the Hawke's Bay Regional Council announced that after an "extensive investigation" it would not file charges against he company.
Construction work will typically take place between 7.30am and 6pm. Access to the toilet block and public roads will be maintained while beach access is limited in the direct vicinity of the work area.