Smoke from the Downer bitumen plant area in Ravensbourne Rd drifts over Logan Park on Tuesday.
Otago Regional Council environmental monitoring and operations director Jeff Donaldson said staff checked on the plant's emissions and found it to be complying with its resource consent conditions.
A recent audit of those requirements found it was only emitting to air half the level it was allowed to under its consent.
It was difficult to tell how much of the smoke came from the plant and how much from nearby chimneys, he said.
No-one had complained to the council. Weather conditions such as a lack of wind and an inversion layer could also make smoke more apparent.
Photo by Stephen Jaquiery.
