It could mean a costly upgrade of the brewery's boiler system, similar to that being undertaken at the Otago Polytechnic and University of Otago halls, and required of the former hospital boiler a decade ago.
The Otago Regional Council recently invited the beer producer, which is undergoing a $29 million upgrade to increase its brewing capacity, to its offices to express concern about increased emissions from the brewery.
Speight's production had increased from about five brews a week to 25 after the Christchurch earthquake, which extensively damaged Lion's Canterbury brewing plant.
Council resource management director Selva Selvarajah said the increase in smoke from the plant was not something the council could continue to allow, so the company was asked to come up with measures to reduce smoke levels and present them to the council within a month.
In the short term, the brewery could try a different coal to fire its four boilers but that was not a long-term solution, he said.
The council would prefer the company put its money into a permanent solution.
While the brewery was important to Dunedin and its economy, like other big industry in the city, it needed to be aware expectations of air quality today were a lot higher than many consents granted in the 1990s provided.
Speight's consent, which expires in 2018, was "lenient" by today's standards, he said. The company had a good compliance record.
"Things have changed a lot."
If the company decided to do a major upgrade to meet new emission standards, the council would look at giving it a year to do the work, he said.
In 2003, it was reported it cost Meridian $3 million to upgrade the former hospital boiler to meet modern standards.
Dunedin was in air shed two and each year exceeded the national emissions standard, so it was important they were lowered, he said.
While industry might only contribute 10% of the city's emissions, in the small areas surrounding the industry, they could contribute significantly more.
A Speight's spokeswoman could not be contacted for comment yesterday.
