Contractors commenced the removal of contaminated stockpiles from the former sewerage treatment plant and new depot site at South Grafton last week.
Clarence valley Council (CVC) has set up a website dedicated to the removal of the contaminated material, which the council’s works and civil director Troy Anderson said in a media release, was prompted by “a lot of interest in the process because of the presence of asbestos and other contaminants”.
The website, clarenceconversations.com.au, includes a frequently asked questions section (FAQ), document library and photographs of the works in progress – these sections will be updated or expanded as the removal progresses.
Mr Anderson said any enquiries regarding the removal of the contaminated soil should be made to the council through its customer service system, 6643 0200, or via email to [email protected], not the contractors who are onsite.
Queensland-based material management and plant hire business, Lantrak, is trucking the material to Swanbank in south east Queensland.
Hutchinsons Builders (J Hutchinson Pty Ltd) have a 12-month permit (beginning on November 15), issued by the Queensland Department of Environment and Heritage Protection, for the removal and disposal of [a maximum volume of] 35,000 cubic metres of asbestos contaminated soil.
A cubic metre of soil weighs between 1.2 and 1.7 tonnes, which equates to a total tonnage ranging from 42,000 to 59,500 tonnes.
Mr Anderson said that it will cost $70 per tonne to “transport and dispose” of the contaminated material; however, he said that “loading and site works costs are additional”.
Assuming that the maximum of 35,000 cubic metres of soil is disposed of, the transport and disposal estimate (by the Independent) would range from $2.94million to $4.165million.
Mr Anderson said that “the density of the material and the size of the trucks vary, but a reasonable estimate is about 20 cubic metres per truck”, which equates to 1,750 truck movements, assuming 35,000 cubic metres of soil is removed from the site.
“We estimate [that the removal of contaminated material will take] about four to six weeks, but that will depend on the quantity of material that has to be moved,” Mr Anderson said.
“The first day of operations was to determine how efficiently trucks could be moved through the site safely and efficiently while meeting all environmental control measures.
“The methods will be refined over the next few days and we will have a better idea of how many trucks a day can move through after that.”
The Independent asked: If a depot was not being built there, would the entire site have been remediated, as it is being done now?
Mr Anderson replied, “Yes,” and confirmed that the entire site would have had to have been remediated, to meet the NSW Government’s requirement to complete the decommissioning of the old STP.
“The Environment Protection Authority requires the site to be rehabilitated regardless of end use,” Mr Anderson said.
According to CVC’s development proposal to the Joint Regional Planning Panel, the site has been used for “potentially contaminating activities including the STP since 1978 … and large quantities of fill are now located on the site in area 2C [since May/June of 2012]”.
However, Mr Anderson said: “The material that is being dealt with is believed to go back sometime, and not since 2012.”