Night noise to travel up to 20km
Chalice mine worker shuts gate at site of planned 2km-wide Julimar superpit.
Richard Wilkinson* (Retired sound engineer)
RECENT events have prompted me to readdress the anticipated noise disturbance and transport logistics of a proposed large open-cut mine in or near the Julimar Forest.
I wrote in The Herald last year that assuming a base noise level of 90 decibels – similar to that of a noisy motorcycle – the intrusive effect of a large open-cut mine in a quiet environment such as Julimar could be felt up to 20km away.
Even then, a light sleeper may have to close their bedroom windows year-round to get a good night’s rest.Read more
When assessing disruptive impact, the frequency and type of noise – continuous or intermittent – must also be considered.
If crushing or other processing occurs, the base noise level will be considerably higher.
In the 1960s I was involved in establishing noise footprints around European airports when new Boeing 707 passenger aircraft were initially banned due to noise emissions.
Similar work should be done here.
However the most important factor relates to increased transport needs and its effect on the living environment.
Chalice Mining says it plans to extract up to 30 million tonnes of ore every year at Julimar for an initial 18-year period.
This equates to 30 trains up to 1.5km long – or 3000 large trucks – every 24 hours.
Access roads or conveyors would be needed to transport the ore to a railhead and a new standard-gauge rail line would be needed to connect it to the existing network.
My experience as Westrail Operations Research Leader in the early 1980s suggests the existing rail network can’t handle such an increase.
It represents twice the amount of grain already being railed to WA ports each year.
Significant new storage and loading infrastructure would be needed.
Current rail access to Kwinana is limited to perhaps an extra five trains per day at most.
Construction of new roads and railway lines creates extra noise at intrusive levels.
The impact of mining on flora in environmentally sensitive areas may be obvious but damage to animal life may be harder to detect.
These factors need to be investigated before it is too late to stop or limit the project.
We may need certain metals to help reduce climate change but the minerals are available in far less-sensitive environments further from cities, state forests and national parks.
The level of damage that may have already occurred at Chalice Mining’s Julimar test-drilling sites – including on private farmland – needs to be independently tested.
The Avon Valley Environmental Society, of which I have been Treasurer for many years, has met Chalice Mining several times in the past year or so.
At our first meeting about 18 months ago, we gave Chalice Mining a list of questions.
No answers have been forthcoming.
*The author is a university qualified noise expert who has worked in the British aviation and WA rail transport industries.
Chalice Mining later told The Herald that it answered a list of questions last November and is “continuing to investigate” other questions posed about the impact of a mine.