For a period of about 30 minutes the fire discharged a large plume of smoke visible from at least the Links Rd/Expressway roundabout, 6km from the site.
The blaze was noticed by a Hawke's Bay Regional Council enforcement officer driving along the Expressway. When he arrived he saw the fire, which was about 5sq m, fully ablaze.
In Hastings District Court the company's defence counsel, Nicola Graham, told the court Santo Drainage's conduct was "ignorant of the law and reckless, rather than premeditated".
Judge Melinda Dickey said the company's culpability was high, and imposed a fine of $12,555, with 90 per cent to be paid to council.
Outdoor fires of any sort are prohibited during winter under the Hawke's Bay Regional Resource Management Plan, unless under specific circumstances.
Regional council pollution response and enforcement team leader, Mike Alebardi said the council had completed five prosecutions for illegal burning in the past three years and had three under way.
Council chairman Rex Graham said he appreciated the court taking a "tough position".
"The court has recognised the importance of this issue and that illegal burning cannot be tolerated," Graham said.
"We hope this sends a very serious message to people who think they can pollute our air and affect the health of our community."
There has already been one exceedance of air quality standards (National Environmental Standards) this winter in the Hastings airshed.
Alebardi says the council simply wanted to reinforce that this kind of non-compliance was unacceptable.
"We have shown we will pursue these activities through the court if necessary. It's one of the strongest signals we can send to discourage others not to burn prohibited items."
Anyone with information about unauthorised discharges to land, air or water, can contact the council's 24/7 Pollution Hotline on 0800 108 838.
