Firefighters fear a large fire that tore through a Northland landfill on the hottest day so far this summer could flare up again as investigators begin an investigation into how the blaze started.
Four helicopters, diggers and bulldozers and about 30 firefighters from Whangārei, Portland, Marsden Pt, Onerahi and Hikurangi battled for most of Saturday afternoon and into the early evening to bring the blaze at the Puwera Landfill under control.
The landfill, 10km south of Whangārei, is jointly run by the Whangārei District Council and Northland Waste.
Landfill staff noticed the fire about 2.30pm on Saturday and it wasn't long before large plumes of black smoke could be seen from kilometres away as firefighters battled to bring it under control in 28C temperature.
According to MetService, Saturday was the hottest day in Whangārei so far this summer and daytime temperatures in the late 20s were forecast across Northland throughout this week.
A firefighter from Whangārei and another from Hikurangi were treated for heat stress by St John paramedics from Bream Bay at the fire scene on Saturday.
They did not require hospitalisation and returned to the landfill yesterday morning as part of a fire crew monitoring the situation.
Paul Ballantine, Whangārei Fire Brigade senior station officer, said the fire could potentially reignite as combustible materials in the landfill continued to burn underneath.
Dump trucks covered extinguished areas with dirt on Saturday night after firefighters left the scene.
Fire investigator Gary Beer has started an investigation into the blaze.
Ballantine was part of the crew that attended the fire, which he described as "fairly challenging" given the amount of combustible materials and the heat at that time of the day.
Protective gear, including breathing apparatus, normally used while fighting fires inside buildings had to be worn at the landfill due to the heat from the blaze combined with the heat of the day, he said.
"The heat stress and the temperature at the time were some of the reasons we decided to use helicopters. At the end of the day, the choppers were the best resource."
Ballantine said since there was no reticulated water supply at the landfill, it was easier to use the helicopters and they filled up at nearby farm dams, while the fire trucks had to make runs to the Portland Fire Station for water.
He said firefighters initially focused on containing the fire and stopping it from spreading to a nearby hill, before the helicopters and heavy machinery moved in.
"The fire was fairly noxious and we've had to rotate and rehydrate our guys. We tried to take the heat out of the fire, to try and smother the fire and remove the oxygen.
"The clothing we wear is three layers thick and it badly overheats, especially on a hot day.
"Two of our firefighters were treated for heat stress. It was a case of dehydration and the choppers allowed us to pull back in that heat."
Ballantine said although the fire was largely contained, it was still burning underneath and could potentially flare up given similar temperatures were expected this week. A fire team would remain on site until there was no longer a risk.
Whangārei District Councillor Nicholas Connop said fire would not have been lit on purpose at all.
He said no fires were lit to burn off rubbish, and gases that were created were removed and rubbish buried.
"Until an investigation takes place we can only speculate as to what happened. And even trying to investigate the incident will be a mission due to the location and the amount of miscellaneous trash," he said.
The Northland District Health Board advised people to stay indoors and to keep windows closed if the smoke from the fire irritated their eyes, nose, throat and airways.
Symptoms of irritation can include runny or sore eyes, dry or sore throat, sore nose, cough, tightness of the chest or difficulty breathing.
Public Health would continue to monitor the situation and provide additional advice if anything changed.
Whangarei Flying Club captain and flight instructor Rusty Russell was returning from Dargaville in a microlight and saw a black puff going off.
"I thought that needed a little bit of investigation so I went back to base in Onerahi then flew to where the fire was. It was quite impressive. You could see it from 40 miles out.
"It was such a clear day that you could see Great Barrier Island. At one stage there was black smoke going up and then it changed to grey," he recalled.