Pressure to reduce winter time smog is fuelling criticism at rural land owners burning off horticultural waste, but doing so within the guidelines managed by the Hawke's Bay Regional Council.
There were tight rules around outdoor fires within the Napier and Hastings air sheds in an attempt to comply with national air quality standards to reduce pollution.
Te Mata Mushrooms, in rural Havelock North, held a controlled burn off on Saturday. Regional council staff visited the site to check the fire would be managed correctly and the site was not in the Hastings air shed. But when the fires were lit on Saturday, more smoke than anticipated was produced, and was visible kilometres away.
Reader Mark Todd snapped a photo of the fire and asked: "How can rural people pollute the air for days ... when the rest of us have been told to install new fire places and burn dry wood."
Te Mata Mushrooms owner Michael Whittaker said the company did all it could to make sure it complied with the rules.
"There was more smoke than we expected and I apologise to people for that.
We followed the regional council requirements to the letter of the law and I am sorry there was more smoke than anticipated."
Mr Whittaker agreed there was now more public pressure for people to stop burning fires in backyards and, in particular, in rural areas where smoke could blow over urban centres.
"We are certainly keeping pace with public concern and it is something important to us, especially in other areas of our operation at Te Mata Mushrooms."
The regional council said it received one complaint about the smoke and visited the site. It was outside of the air shed and advice was given to prevent a similar problem in the future.
Council's senior scientist climate and air, Dr Kathleen Kozyniak, said Napier and Hastings air sheds had exceeded the national environmental standards for PM10, or fine particles, allowed to be released into the air.
She said the type of PM10 pointed to home heating domestic fires as the key contributor to the breaches. "Hence there is no getting away from having to address that issue and to encourage city people to adopt clean heating methods."
Dr Kozyniak said burning material in rural areas was "fairly isolated" in terms of land area, tended to be short-lived, and fewer people were exposed to it.
Rural fires occurred mostly during the day when wind dispersed the smoke.
"However, if it is causing a nuisance beyond the property it's located in, including affecting visibility on nearby roads, then people can get in touch with us and our compliance team," she said.
"If the rural land is within the Napier and Hastings air sheds, there are rules about the burning of material during the late autumn and winter months."