Residents have said the noise from the fans - one of which is only 100m from a house - is unbearable and the council's regulations that allow that level of noise are confusing and not strict enough.
The October Novo Group report said the noise was unreasonable for three houses to the north and northeast of the turbines, but reasonable for houses to the northwest, west, southwest, south and east of the turbines.
However, a follow-up letter on November 7 said following additional consideration of the "impulsive sound" characteristic of the turbines - the "rapid-fluctuating sound characteristic from the frost fan sound" - it was now considered the noise for the houses to the northwest, west, southwest and south was also unreasonable.
The October report said noise measurements were taken at various locations near Leaning Rock orchards and the frost turbines were the "dominant noise source" at all the locations - there were no other rural or agricultural activities taking place at the time that caused "obvious or undue" noise. Five measurements were taken at various locations to assess the cumulative noise of the frost fans.
Campbell said the Novo Group report was being peer-reviewed by Leaning Rock.
When asked if the council was going to take any action following the Novo Group conclusion that the frost turbine noise was unreasonable, such as issue abatement notices or prepare reports for councillors about the possibility of council regulations being changed, Campbell said "at this stage we are still awaiting confirmation of a meeting date with the orchardists, which is reliant on their peer review of the noise report".
He said the frost fan regulations would be revisited as part of the council's district plan review "unless council wants us to look at them sooner".
No-one at the council has given a precise estimate of how long the district plan review will take, but it has previously been estimated as at least several years.
