Stirling McGregor v Tilt Renewables Australia Pty Ltd

The appeal concerned an environmental planning dispute regarding a proposed wind farm development. The parties were Stirling McGregor, the objector, and Tilt Renewables Australia Pty Ltd, the developer. The matter came before the Environment, Resources and Development Court of South Australia.

The central legal issues before the Court were whether the proposed wind farm development would generate noise, including infrasound and low-frequency noise, at levels that would cause unreasonable interference with the amenity of neighbouring properties, and whether such noise could lead to adverse health effects. The Court was required to consider the evidence presented by expert witnesses on noise impacts and to determine the appropriate application of the 2009 Guidelines for wind farm noise in South Australia.

The Court accepted the evidence of Mr. Turnbull, an acoustic engineer called by the developer, who conducted noise predictions and measurements in accordance with the 2009 Guidelines. Mr. Turnbull's evidence indicated that the predicted noise levels from the wind farm would comply with the relevant guidelines, and that infrasound produced by modern wind turbines was at levels below perception and no greater than other common environmental noise sources. The Court also considered Professor Wittert's conclusions, which found no evidence that audible noise, low-frequency noise, or infrasound from compliant wind farms posed a significant risk to health, although annoyance could occur in a small number of individuals. The Court rejected the objector's criticism that the 2009 Guidelines' averaging of background noise levels was flawed, finding that a reasonable approach to noise assessment should not condemn a proposal based on absolute worst-case scenarios at a single moment in time, and that the guidelines were consistent with the Development Plan's aim of protecting against "unreasonable" interference with amenity.