The Central Otago District Council's rules surrounding frost-fighting wind turbines have come in for further criticism, as more residents speak up about noise pollution in the district.
Letts Gully family Katie and Hunter Hill spoke up last week about the "unbearable" noise from turbines near their home on orchards owned and managed by Leaning Rock Cherries Ltd.
There were no turbines on neighbouring orchards when Mr Hill bought the property 12 years ago, but now there are two about 250m away from their house and one 100m away.
Leaning Rock manager Pete Bennie has declined to comment, but last week more Letts Gully residents spoke out in support of the Hills.
John Grant, of Hawkdun Rise Vineyard and Accommodation, who spoke up several years ago about the issue, said noise from frost-fighting turbines was getting worse.
Nigel Murray, who lives several hundred metres away from turbines, said pollution from any other industry was required to be controlled and it was "unreasonable for any industry to operate to the detriment of surrounding residents".
Other residents responded on Facebook.
"Katie is not the only one having to put up with being woken in the night in both autumn and spring," Tim Whittaker, who also lives near Leaning Rock orchards, said.
"We came home to see a wind machine straight out our kitchen window at just over 100m. A new orchard on the boundary, high poles for the cover structure, no consents needed, soil build up on our fences, water running down on to our property. Not even any consultation."
Katie Mulholland said "this is [a] huge problem for this area of Alexandra, the season when the turbines or helicopters are out is getting longer - just started this weekend and will go through until at least early December - and we live around 1km away and it wakes us up, so I can only imagine what Katie and her family are living through".
• The Central Otago District Council's district plan allows frost-fighting wind turbines to be built as close as 300m from a residential or rural settlement resource area, and 100m from a house within a rural or rural residential zone.
• Any turbine used for frost control must not exceed 65 decibels at 300m. There is no rule about noise at 100m.
• World Health Organisation recommendations say exposure to wind turbine noise louder than 45 decibels is associated with adverse health effects.
• Central Otago turbines are allowed to be used during the "frost danger period" until the leaves of the plant are dry and the air temperature has reached 1degC. But there is no definition of the "frost danger period" in the district plan.
•No monitoring of noise from turbines has been done for several years, and no abatement notices have been issued.
• A recent determination from the Ministry of Business, Innovation and Employment means a building consent is no longer required to install a frost fighting turbine.
Cromwell resident David Griffin said he also lived near a frost fan - 108m from his Ripponvale Rd home - and had to install double glazing and extra insulation to help combat noise from the turbine which was measured at more than 60 decibels inside his house.
But those angry and upset about the noise blamed the lack of council regulations for the issue.
"I have been through the same issues with the council but they just don't get it," Griffin said.
"Frost fans are allowed to be installed 100m away from a home but the sound level around 60 decibels is measured at 300m which does not seem right to me ... Both my neighbours have frost fans and it's not their fault, it's the [council] rules that are [at fault]."
Council planning manager David Campbell said frost-fan turbine noise had not been monitored for several years, but noise from turbines near the Hills' house would now be measured, later this week.
For an abatement notice to be issued, noise would need to exceed the noise limits, as measured at 300m, Campbell said.
When asked why the noise limits were set at 300m, when turbines could be installed 100m from a rural home, Campbell said the noise could be extrapolated for houses closer than the 300m noise measurement point.