Century has several programs in place to minimise and monitor the impacts of its operations on the township of Karumba and surrounding waters.
Community members at Mornington Island.
Karumba Emissions Monitoring Program
When stored for extended period, zinc can began to generate sulphur dioxide emissions. To minimise the potential for this to occur, Century carefully manages concentrate storage conditions and lengths.
However, unforeseen circumstances may mean that concentrates occasionally need to be stored for longer periods. If this is required, additional precautions are taken to prevent and minimise the generation of sulphur dioxide emissions.
The detection of sulphur dioxide at certain levels within the concentrate storage shed triggers the commencement of a community monitoring program. It is important to note that it is very unlikely that emissions may be detected outside of the storage shed.
The monitoring program allows us to quickly notify residents in the unlikely event that sulphur dioxide emissions became detectable outside of the facility.
Karumba health monitoring program
As well as zinc, Century also produces smaller quantities of lead concentrate.
Century takes all precautions to limit exposure by its workforce, community members and others to lead. This includes additional safety precautions for the handling of lead concentrate and stringent hygiene practices.
As an additional measure to ensure their health and safety, MMG regularly monitors the in-blood lead levels of its employees. This program is also extended to Karumba community members on an annual basis.
Century advertises its health monitoring program in local publications and around Karumba, inviting residents and visitors to undertake free blood testing to monitor for lead exposure. The samples are then tested in an independent laboratory. Results are kept confidential and provided to participants.
Karumba Water Tank Testing Program
Century commissions sampling of rainwater tanks throughout Karumba prior to and after each wet season.
The rainwater tank samples are analysed by an independent laboratory for total concentrations of arsenic, cadmium, lead and zinc against the Australian Drinking Water Guidelines (ADWG) values.
As each sample is collected, other information – such as the size of the tank, tank age, volume of water held, use of collected rainwater, cleaning history, presence of first flush diversion and construction material – is also gathered.
The results of each rainwater tank sample are provided to participating residents.
Karumba - local sediment and sea grass monitoring
Century has an extensive monitoring regime in the Norman River and surrounding marine environment to ensure our Port operations are not impacting the local environment.
The monitoring regime, which has been in place for more than 10 years, includes:
- Routine monitoring of water discharges to the Norman River;
- Seawater, seagrass and sediment sampling; and
- Regular monitoring of commercial fisheries (barramundi, grunter and mud crabs).
Samples are frozen and transported to Charles Darwin University for analysis. Analysis conducted includes comparing metal and arsenic concentrate and lead isotope ratios to current Food Safety Australia New Zealand Standards (FSANZ; 2009).
Results have consistently shown that Century’s operations are not impacting on the local marine environment.