About 2000 litres of oil have been recovered following a catastrophic factory fire in North Canterbury that left a toxic slick coating Kaiapoi rivers and workers facing an uncertain future.
Sutton Tools went up in flames on Sunday morning, flushing quenching fluid from the drill bit manufacturer through stormwater drains and into the region's rivers.
Shocked staff, many of whom have worked at the factory for decades, are worried about their jobs.
While the source of the spill has been contained, oil has been found in the Cam/Ruataniwha, Kaiapoi and Waimakariri Rivers and downstream to where the Waimakariri River meets the sea.
Booms were used to capture and soak up the oil, along with sorbents and sucker trucks, while flood barriers at the Cam/Ruataniwha River were used to hold water back.
Sutton Tools general manager Kevin Donovan said the Australian-owned company behind the business had been supportive of its 100 Kaiapoi staff.
"Our staff are obviously really shocked. Many of them have worked here for decades, there are family ties and strong community ties around the factory," he said.
"Our number one focus is trying to allay their fears and establish what we can do and how we can get back up and running.
"We've given a commitment to our staff to continue paying them for the medium-term."
Donovan said the "catastrophic" fire had caused the roof to collapse and badly damaged custom-made machines, although some might be able to be salvaged.
He said the cause of the fire remained a mystery.
"There's nothing really obvious or that we can put our finger on," he said.
Firefighters said it could take several days to establish the cause of the blaze.
Waimakariri District Council mayor Dan Gordon said he hoped the Australian-owned business would remain in the town.
"It's really devastating news for Kaiapoi. Myself and our council will do everything we can to make sure we keep those jobs here," he said.
"It's been in our town for 60 years, so it's a huge impact to have a business like this gutted and destroyed."
Environment Canterbury regional on-scene commander Emma Parr said about 1100 litres of oil was recovered from the rivers and a further 800 from the factory sump.
"It's still coming into our containment booms, just a lot slower than yesterday," she said.
"We expect to get another couple of hundred litres off the surface of the water."
Parr said the number of rivers affected and the tides had made the recovery effort difficult.
Wildlife experts have discovered five birds covered in oil, one of which has been taken to a vet.
Parr said fish did not appear to be suffering as a result of the spill.
People were urged to avoid the rivers until the weekend, when the residual oil should have cleared.