A Northland farmer who tried to burn more than 100 tyres in a rubbish fire polluted the air with black, noxious smoke and contaminated the ground with toxic oil.

Bernard Glen Stewart was fined more than $33,000 earlier this month, for lighting the fire then burying the remains where it could contaminate the land and groundwater.

The fire took place in January 2022, on a property south of Kaiwaka which Stewart leased to graze livestock.

Neighbours called firefighters and the Northland Regional Council worried about how the toxic blaze could affect their health.

Firefighters found a smouldering pile with the remains of 100 to 130 tyres, most of which were possibly truck or tractor tyres.

Large amounts of melted rubber and steel belting from tyres was also found, along with some unburnt tyres.

Firefighters used about 13,600 litres of water to fully extinguish the blaze.

Stewart later buried the remains of the fire and initially told council enforcement officers the blaze may have contained a few tyres, but he didn’t mean to burn them.

He later admitted three charges of polluting the air by burning the tyres, and contaminating the land and potentially groundwater by burying the fire.

Council compliance monitoring manager Tess Dacre said burning tyres is “really bad”, both for the environment and for people’s health.

“It produces black smoke and contains nasty chemicals that affect people’s health.”

The pollutants from burning tyres, such as dioxins, are known to be carcinogenic and can stay in the environment for hundreds of years, she said.

Others like carbon monoxide and nitrogen dioxide can impact breathing.

Dacre said while there are many old tyres on farms across Northland, most can be given a second life.

“They’re not a problem if you don’t burn them. They’re traditionally used to hold down silage [covers], which is a perfectly acceptable practice.”

Dacre accepted there is a cost if people want to dispose of tyres.

In this case, it would have cost around $3000 to take the tyres to the Kaiwaka transfer station, which was 8km away.

But the $33,000 fine should act as a deterrent to anyone considering burning tyres instead of disposing of them correctly, she said.

“This one, we think, is a good message to people that it’s not worth taking that risk.”

In 2022, former Whangārei mayor Stan Semenoff was fined more than $15,000 for allowing a fire of tyres, treated logs and plastics to be lit and allowing the fire to continue burning the following day.

Stewart was sentenced by Judge David Kirkpatrick in the Whangarei District Court September 4.

Stewart told council staff he was trying to get rid of a pile of waste left by a previous tenant and did not know he was not allowed to burn tyres, the recently released sentencing notes show.

But the judge said the thick smoke and noxious fumes should make anybody realise burning tyres is unlikely to be allowed, and a person using the land should know burying the remains of such a fire could leach contaminants into the groundwater.

After the fire was buried, the council added the land to its register for hazardous activities and industries list, also known as HAIL.

This showed the seriousness of the situation, as it could reduce options for future land use or increase costs of future development, Judge Kirkpatrick said.

The judge gave a discount for Stewart’s good character, co-operation and willingness to make amends, including washing his neighbours’ roofs after the fire.

He was fined $20,000 for the fire and $6625 for each of the “burial” offences. Court costs of $130 and a solicitor’s fee of $113 were also added on each charge.

90% of the fines will be paid to Northland Regional Council as prosecutor.