Noise measurements from a frost-fighting turbine that is 100m from a family's home show Central Otago District Council rules about the turbines are "the real problem", the family says.
Katie and Hunter Hill, and various other Lett's Gully residents, have complained to the council repeatedly about the noise from turbines on nearby Leaning Rock Cherries Ltd orchards.
Noise measurements were taken recently of a turbine 100m from the Hills' house, at their request.
The results were within the council rules and therefore showed the turbine was operating legally, council planning manager David Campbell said.
But Mrs Hill said the council rules were confusing and not strict enough.
"That's what we've been trying to tell them [the council] all along, that the regulations need changing as the noise allowance is far too high, particularly with regard to what the World Health Organisation [WHO] recommends," Hill said.
WHO recommendations say exposure to wind turbine noise louder than 45 decibels is associated with adverse health effects.
Hill said the noise from the turbine 100m from their home was "unbearable" and sounded like helicopters above their house.
About six other people have also told the Otago Daily Times they are concerned about the noise. Some of the people have been complaining to the council about the noise for up to three years.
Hill said she would like to see noise measurements of the turbine 100m from their home taken again when two other turbines 250m from their home were also on, believing the noise effects to be cumulative.
She said it was also not known if the turbine 100m from their home was operating at full speed when it was measured.
Campbell said he did not know the margin of error for noise measurements.
He said the council had requested the noise measurements be taken again, and when other turbines were also operating, and would make sure the turbines were operating at full speed when measured.
The measurements would be done by a specialist. Their timing was to be confirmed.
Leaning Rock manager Pete Bennie declined to comment on the measurements, saying "Leaning Rock Cherries does not intend to enter into any further dialogue via the media.
"Leaning Rock Cherries welcome any neighbours meet with us to discuss their concerns or suggestions".
• Noise levels 300m from a frostfighting turbine must be at or below 65dB L10 (the level which is equalled or exceeded 10% over the time period measured).
• Turbines may be built as close as 300m from a residential or rural settlement
resource area, but as close as 100m from a house within a rural or rural residential zone.
• No specification for level of noise allowed 100m from a turbine.
• Measurements taken recently for a turbine 100m from the Hill family home in Lett's Gully Rd, near Alexandra, showed the noise levels at their home when the turbine was on were at or above 69.9 decibels L10, and averaged 66.7 decibels Leq (average sound level over the same measurement period).
• The noise measured 300m from the turbine was at or above 61.7 decibels L10 and 58.6 decibels Leq.