Independent monitoring begins around Tiwai smelter
Media Release - 24 January 2022
Independent monitoring begins around Tiwai smelter
Independent monitoring is underway into the impact of any contaminants from the Tiwai aluminium smelter on the adjacent coastal marine area.
Earlier in the year, New Zealand Aluminium Smelters (NZAS) commissioned a report about the contamination at its site. While the data in the report was useful, Environment Southland had an expert assessment done of it by EHS Support, which noted “numerous legacy and ongoing sources of contamination to the environment” and key gaps in the data. The gaps related to the surrounding coastal marine area, the onsite 50-year-old landfill (now closed) and the on-site spent cell liner pad.
Environment Southland chief executive Wilma Falconer said: “The objective of this independent monitoring is to determine whether there are any contamination issues relating to the adjacent coastal environment and the 50-year-old landfill on the Tiwai site.
“While it is the smelter’s responsibility to remediate the contamination, it is the Council’s responsibility to set the standard of that remediation. To be able to do that we need to understand the level of contamination and its potential impacts and these investigations will help us to do that.”
EHS Support designed the independent monitoring programme and is undertaking the monitoring.
The monitoring includes sampling and analysis of:
- Sediment and porewater (free water contained in pores in sediment) and sea water from the intertidal area of Bluff Harbour (down gradient of the north, west and south drains on the Tiwai site) and Foveaux Strait, adjacent to NZAS’ key operations (landfill, ouvea storage, spent cell liner pad areas).
- Sediment, sea water and soil conditions from background samples located in Bluff Harbour, Awarua Bay and Foveaux Strait areas
- Groundwater from selected wells adjacent to the coastal marine area
NZAS has an extensive network of wells on the peninsula for monitoring groundwater quality and hydrogeology and has added a further 46 wells this year, eight of which were requested by Environment Southland for additional monitoring purposes. Environment Southland placed some data loggers into some of the wells in December, which measure the behaviour of the groundwater.
NZAS holds eight discharge and water consents with Environment Southland. As part of the consent conditions, it must undertake certain monitoring requirements and provide the results to Environment Southland, which it has complied with. The consent relating to the recently closed landfill on the site, is expiring at the end of 2023.
The independent monitoring programme is an initial part of a wider programme of work to ensure a comprehensive and integrated approach is taken to understanding the state of contamination and the required remediation of the Tiwai aluminium smelter site and surrounding environment. This work followed a request from David Parker, Minister for the Environment, to investigate the extent of the contamination.
NZAS has been working cooperatively with Environment Southland, providing information, making improvements to waste management practices and allowing access to the site.
“We are pleased to be getting this next phase of our work programme underway. It is really important because it will give us an indication of any further contamination at the site and in the wider environment.
The independent monitoring programme got underway last week. The field work will take about one month to complete. The results will be analysed and are expected to be made publicly available in the first half of 2023.
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For more information go to: https://www.es.govt.nz/environment/industry/new-zealand-aluminium-smelters
