Question On Notice No. 764 asked in the Legislative Council on 13 March 2018 by Hon Robin Chapple
Question Directed to the: Minister for Environment
Parliament: 40 Session: 1
Tabled Paper No: 1265-
View tabled paper
Question
(1) I refer to the contaminated site at the former Pillara Lead and Zinc Mine on Gogo station, and ask:
(a) is the department aware of thallium and/or other heavy metals present in the groundwater and soil at Gogo station;
(b) if yes to (a), are thallium and/or other heavy metals present in the area of the proposed irrigation development on Gogo station;
(c) has analysis been undertaken of the risk of thallium or heavy metals in the soils and/or waterways at Gogo station, and/or in the variety of proposed food crops or beef at Gogo Station if the proposed irrigated agriculture development was to go ahead;
(d) if no to (c), why not;
(e) if yes to (c), can the Minister provide a summary of outcomes and a copy of the analysis;
(f) does the contaminated site pose a potential, short, medium or long term risk to groundwater at Gogo Station, for irrigation or human consumption purposes;
(g) does the contaminated site pose a potential short, medium or long term risk of heavy metal or thallium contamination of surface water, wetlands or soil at Gogo Station;
(h) could trends of increasing rainfall cause an increased risk of contamination on Gogo Station as a result of uncontrolled flooding of the contaminated site;
(i) can the Minister advise if dams designed to capture overland flow downstream from the contaminated site on Gogo Station could contribute to increasing the concentrations of thallium and other heavy metals over time;
(j) have there been any known spills or leaks from the contaminated site in the last five years;
(k) if yes to (j), what remediation was done and what is the assessment of the effectiveness of this remediation; and
(l) have site specific screening criteria been developed for assessing water quality for livestock or irrigation at the site, particularly for thallium?
(2) I refer, to the document "Kimberley cropping – submission for discussion of business case proposal Oct 2014" that was submitted by the proponent seeking Government support for irrigated agriculture at Gogo Station and was recently released under a Freedom of Information request, and ask:
(a) the document states that 10.5l/ha of various herbicides would be expected to be applied for irrigated sorghum crops at Gogo Station via aerial spraying (based on figures given by the proponent that are provided as an estimate for Gogo based on DPI NSW figures). Have any studies been undertaken into the potential health or environmental impacts of this spraying program;
(b) if no to (a), why not;
(c) if yes to (a), can the Minister provide a summary of outcomes and a copy of the assessment;
(d) if no to (c), why not;
(e) the document outlines the amount of fertilizers that the proponent expects will be needed to grow irrigated crops on Gogo Station (based on figures given by the proponent that are provided as an estimate for Gogo based on DPI NSW figures). Has the Department assessed the effects of the proposed fertilizer use at Gogo station for their impact on the Fitzroy River and local wetlands and creeks;
(f) if no to (e), why not;
(g) if yes to (e), can the Minister provide a summary of outcomes and a copy of the assessment; and
(h) if no to (g), why not?
Answered on 11 April 2018
(1)
(a) Yes. The then Department of Environment Regulation, now the Department of Water and Environmental Regulation, first classified a portion of the Gogo Station, comprising four mining tenements associated with the former Pillara lead and zinc mine, as contaminated – remediation required under the Contaminated Sites Act 2003 on 14 April 2015. Contamination issues at the site include the presence of thallium in water discharging from a northern vent rise.
(b) Given the size of Gogo Station, it is likely that much of the station is unaffected by contamination at the former mine site. The southern boundary of the proposed irrigation development lies approximately three kilometres north of the former Pillara mine. The mine site operator, Teck Australia Pty Ltd, has commissioned a Detailed Site Investigation (DSI) of the former mine site, which will determine the extent of contamination and assess the suitability of surface water and groundwater quality at and near the mine site for pastoral activities. The Department expects to receive the DSI report from Teck in May 2018.
(c) A number of soil and water investigations have already been carried out at the former Pillara mine site, and (as indicated in (b) above) a DSI is underway. In addition, water from existing irrigation bores and tissue from the leaves of sorghum plants on Gogo Station were tested in December 2015. Thallium concentrations in those samples were below the laboratory’s limit of reporting.
(d) Not applicable.
(e) I table the Preliminary Site Investigation (PSI) prepared by Teck’s consultant in August 2016, which provides a summary of the investigations at the mine site reported to date. The PSI includes the results of analyses.
(f) Water at parts of the mine site is known to be unsuitable for agricultural irrigation, human consumption and livestock watering. The DSI currently underway will provide additional information on the extent of contamination.
(g) – (h) The DSI will inform an assessment of the risk posed by contamination to human health and the environment, including to soil, water and ecosystems on Gogo Station, both now and into the future.
(i) The design of any proposed water storage structures and the likely quality of the water captured will be considered in the Environmental Protection Authority’s impact assessment of the Gogo Station Agricultural Development proposal.
(j) No. The former mine site was placed into care and maintenance in 2008 and the majority of infrastructure at the site has been decommissioned and removed.
(k) Not applicable
(l) Site specific screening criteria are being developed as part of the DSI.
(2)(a) The Department of Water and Environmental Regulation is unaware of any studies undertaken in this regard.
(b) The EPA determined that the Gogo project would be subject to a Public Environmental Review. A factor in the EPA assessment is the “potential impacts on soil and water quality from irrigation of land for cropping”. Another relevant factor is the “potential impact to the social surroundings of the Fitzroy River”. The studies to determine and mitigate the risks to these factors would be part of the work required for the public review document.
(c) Not applicable
(d) Not applicable
(e) No
(f) The Department of Water and Environmental Regulation’s EPA Services directorate will assess this information once it is provided as part of the Public Environmental Review.
(g) Not applicable
(h) Not applicable