Monday, 20 April 2015

The proposed Adare motocross facility exceeds even its own maximum noise limits

The Noise Impact Assessment presented in the Development Application for the Adare motocross facility has some interesting bits in it.  Here are a few.

Background Noise

Background (ambient) noise measurements were done over a one week period in August 2014.

The table below presents three different measures of background noise, extracted from the same data set.  These represent the three main ways of measuring background noise.
The L90 measurements are similar to the values recorded for background noise at properties near the Emu Creek motocross track (before it ceased operating).  They are more or less what would be expected in a quiet rural/natural environment such as we have here in Adare/Vinegar Hill.

In such a rural/natural environment with high amenity values (and high resident expectations) for "peace and quiet" then the maximum acceptable imposed noise level should be no more than background+5dB.  This standard has been used at other locations in Queensland and in NSW.

So, taking Leq readings, the maximum acceptable noise levels for daytime operation (7am to 6pm) would be 37+5dB = 42dB.  And for evenings (6pm to 10pm) it would be 30+5dB = 35dB.  Note that background noise levels were measured in the open air, so indoor background levels would be lower and imposed noise maxima would also be lower than these figures.

Predicted Noise Levels at Houses

The table below is a key to the locations of "Receivers" (i.e. houses) for which noise levels were predicted by the acoustic model used by the consultant.  The two tables after it refer to Receivers No. 1-18, and the street addresses of these are given in the right-hand column of the table below.
Receiver Locations for Noise Predictions in Following Tables (none of the directions given are accurate - the consultant fails to understand that "due" means "exactly" in this context)

These are the predicted noise levels for daytime operation (9am to 4pm).  Note that the Applicant has chosen to adopt the criteria of 50dB for daytime operation and 35dB for evening operation. No justification is provided for this in the Application, and there has been no attempt to relate these values to measured background levels or to take into account annoyance effects of motocross noise.

Nevertheless, if we just take the Applicant's maximum noise values, the 50dB value is exceeded at two locations outdoors (whereas background+5=42 is exceeded at eight locations).  For indoors, the Applicant's criterion of 35dB is exceeded at eight locations.

The Applicant has used the same maximum noise levels for evening operation as he used for daytime (50dB outdoors and 35dB indoors).  This is completely unacceptable, considering that the evening background values he measured are 7dB(Leq) lower than daytime backgrounds.  The proposed outdoor 50dB maximum is equalled or exceeded at 11 locations, and the indoor 35dB maximum is exceeded at 14 of the 18 locations.

In summary, the Applicant is not able to meet even his own unjustifiably high maximum noise limits - and I have bee advised that these are 15-20dB(A) higher than those used by another Council.

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