Kawakawa's deputy fire chief Alistair Leitch briefs Whangarei firefighters outside the freezing works during Friday night's ammonia leak. Photo / Peter de Graaf
Kawakawa's deputy fire chief Alistair Leitch briefs Whangarei firefighters outside the freezing works during Friday night's ammonia leak. Photo / Peter de Graaf
A full-scale emergency unfolded in Moerewa after an ammonia leak forced an evacuation of the Affco freezing works and brought firefighters from as far away as Whangarei.
In the early stages of the incident firefighters even considered calling for an evacuation of nearby homes in case the wind blew the hazardous gas towards Taumatamakuku Settlement.
Meat workers at Affco's main entrance during the ammonia leak on Friday. Photo / Peter de Graaf
Sixty workers were on duty about 6.30pm on Friday when the leak occurred in the freezing works' engine room.
Kawakawa fire chief Wayne Martin, whose brigade was first on the scene, said there was already a strong smell of ammonia when his crew arrived at the car park in front of the plant but moments later they were overwhelmed by a cloud of the gas.
He ordered the firefighters back into the truck and they withdrew to a safe distance, setting up a base at Mac's Prime Meats a few hundred metres upwind.
The workers had already evacuated and gathered at an assembly point outside the plant. As the smell intensified they also moved further away into fresh air.
A firefighter dons breathing apparatus as he prepares to enter the freezing works during Friday night's ammonia leak. Photo / Peter de Graaf
In a stroke of good luck a refrigeration specialist and an engineer were at the plant at the time, working on automating some of the plant's systems. The engineer was able to close a valve and isolate the leak.
They were also lucky it was a drizzly, windy evening, which meant the gas dispersed rapidly.
Eight fire appliances from Kawakawa, Kaikohe, Okaihau and Kerikeri responded to the "fourth alarm" call-out, Fire Service code for a major incident. Two St John ambulances attended but were not required.
About 8pm Whangarei's Hazmat hazardous materials mobile command unit arrived along with a snorkel, an appliance and an operational support crew.
Firefighters in breathing apparatus ventilated and decontaminated the plant, using a gas detector to check ammonia levels. Mr Martin said shortly before 9pm the plant was deemed safe enough to hand back to the company.
The plant's evacuation procedures were "flawless", Mr Martin said.
Affco general manager Andy Leonard said the leak was caused by a faulty gasket in the refrigeration plant. The volume of gas involved was "relatively small".
Normal processing was able to resume on Saturday, Mr Leonard said.
WorkSafe is making enquiries into the leak.
Ammonia (NH3) is a colourless, pungent-smelling gas. It is used as a refrigerant but is hazardous in its concentrated form. It can irritate the skin, eyes, nose, throat, and lungs.
