Metal-rich dust blowing from historic stockpiles on the Zinc Works site at Lutana led to soil contamination in the surrounding suburbs (see map). The primary cause of the contamination was identified and stockpiles were covered in the 1990's.
While health assessments conducted in the 1990's found there was no evidence that the health of the residents was affected by the lead and cadmium contamination in soil, the Director of Public Health recommended some precautionary measures be followed by residents in the affected areas so as to further reduce any potential exposure risk. This advice was published in an Information Bulletin in 1999 and sent to the residents of the affected areas.
In 2008 the EPA and Nyrstar carried out a further soil sampling project in order to update information on the degree and extent of this contamination and to see if any changes had occurred. A Project Steering Committee - comprised of representatives from the EPA, the Department of Health and Human Services, Local Councils, the Nyrstar smelter and residents - was formed to guide the study. An independent consultant was engaged to devise the sampling plan and conduct the field work.
The extensive sampling involved the collection of nearly 500 samples. The concentration of metals in soils was not found to be significantly different to previous surveys. Nevertheless, sampling over a broader area and at a higher sampling density, and using modern surveying and spatial analysis techniques, enabled a more precise definition of the boundary of the area affected. This resulted in a reduction of the area where metals levels are above national investigation levels and where precautions to reduce risk are advised.
A review of the historic and recent sampling programs by a biogeochemistry expert from the CSIRO found that the sampling programs were robust and that the data can be considered precise and accurate. The CSIRO also noted in the review that the techniques used to define the affected area were appropriate.
In June 2009, an Information Bulletin and a Background Paper were sent to residents in the affected areas. This Bulletin replaces the bulletin published by the State Government in 1999.
Area Where Metals Levels Are Above National Investigation Levels
To view the zones where precautionary advice applies, to minimise any potential risk from elevated soil-metal levels, in Google maps click here.
While previous measurements of actual human exposure to lead and cadmium have indicated that the metals levels pose a low health risk, residents of the affected area are encouraged to follow the precautionary measures outlined in the revised Bulletin to further reduce any exposure risk. These measures include covering bare areas of soil and only growing home-grown vegetables, particularly leafy greens, in raised beds with clean soil at least 30cm in depth.
A Communications Strategy has been developed by the Project Steering Committee to ensure that both current and future residents and property owners in the affected area are made aware of the soil contamination and the precautionary measures outlined in the Information Bulletin. In addition to the information sent directly to current residents in the affected area as discussed above, other key aspects of the strategy include:
- Councils placing an alert on the Section 337 certificate issued during the conveyancing period. The alert will advise the potential purchaser that the land is within a region of possible soil contamination and to contact the EPA for further advice on the matter;
- Information being made available through the EPA Division’s Property Information Request Service;
- An annual mail out of the Information Bulletin to householders of the affected areas by Nyrstar; and
- Copies of the 2008 Soil Sampling Report being made available at DPIPWE and State libraries.