Dargues Gold Mine, Modification 3: Summary of PAC Meeting, Braidwood (26/7/2016)

The following is a summary of the New South Wales Planning Assessment Commission (PAC) meeting, held on July 26, 2016, at the Braidwood Serviceman’s Club. I have taken the liberty of elaborating on certain issues, while others are condensed by the limitations of memory. This is for the benefit of the wider public who were either not aware of the meeting or could not make it. The subject was the Dargues Gold Mine – to be or not to be. That is the question.

There were 23 registered speakers, of which 22 opposed Modification 3 – upon which the entire Dargues Gold Mine depends. The one registered speaker ‘in support’ was actually very critical of the proponent’s withdrawal of commitments and said nothing in favour of the mine. The official agenda was to comment on the Recommendation by the NSW Department of Planning and Environment, which endorses Modification 3 for approval by the PAC. This served as a departure point for comprehensive criticism of the project and process by which it has (almost) come into existence.

The collective message from public speakers was that the application should be refused, on a multitude of grounds. Front and centre was the mine’s potential for heavy metal contamination of ground and surface water from the mine site near Major’s Creek to the Batemans Marine Park (including the Eurobodalla Shire’s main water supply, the Deua River). Speakers also called for a host of additional conditions to be imposed should the application be approved despite the core message of refusal.

Specific concerns were too numerous to cover, but included:

Composition of floatation tailings: containing heavy metals, including carcinogens, neuro-toxins, and reproductive toxins. Many have no published methods for removal from drinking water.

A direct comparison between flotation tailings chemistry as tabulated in the Environmental Assessment for Modification 3 (p. 57), and Australian Drinking Water Guidelines reveals the following:

Ag (Silver): 4.5 times maximum drinking water threshold (‘x’)
Al (Aluminium): 414,450x
As (Arsenic): <200x
B (Boron): 12.5x
Ba (Barium): 167x
Be (Beryllium): 45x
Cd (Cadmium): 50x
Cr (Chromium): 3,180x
Cu (Copper): 24x
Hg (Mercury): 100x
Mn (Manganese): 1,260x
Mo (Molybdenum): 500x
Ni (Nickel): 6,250x
Pb (Lead): 600x
Sb (Antimony): 1,266.6x
Se (Selenuim): 6x
U (Uranium): 184x

aesthetic (taste) guideline:

Fe (Iron): 49,333x (aesthetic guideline)
Na (Sodium): 166.8x (aesthetic guideline)
Zn (Zinc): 11.3x (aesthetic guideline)

no drinking water guideline (but present in tailings):

Ca (Carbon): no guideline
Co (Cobalt): no guideline
F (Fluorine): no guideline
K (Potassium): no guideline
Mg (Magnesium): no guideline
P (Phosphorus): no guideline
Sn (Tin): no guideline
V (Vanadium): no guideline

Tailings will also contain a class of toxic chemical additive called xanthates. These are are used as ‘floatation agents’ in the separation of gold-bearing concentrate from tailings. Potassium Amyl Xanthate (PAX) is to be used at Dargues, and is toxic to aquatic life at very low concentrations (1 milligram per litre ).

The dual contamination of water with heavy metals and xanthates is common downstream of mining operations, occurring by a range of foreseeable mechanisms (such as overtopping, structural TSF failure, and leachate to groundwater from TSF’s and paste fill). Any of these scenarios, whether occurring in our lifetimes or those of future generations, could result in a plethora of acute and chronic health complications for downstream life. The Moruya River – Batemans Marine Park also stand to be contaminated, as they are part of the same system.

Obsolete design of the tailings storage facility: The proponent claims that the TSF is designed in accordance with Victorian guidelines, Management of Tailings Storage Facilities, (VIC DPI, 2004). This claim is based solely on the permeability of the liner (1 x 10-8); the proponent references not a single other design criteria. Further, these guidelines are outdated. The most recent Victorian guideline (June 2016) specifies a multitude of other requirements, including that a secondary failsafe dam be constructed below the primary wall embankment to prevent contaminated overflow from entering the water catchment. The Dargues TSF is therefore not in line with best or even minimal practice guidelines for the state of Victoria. Nor was it ‘designed in accordance with’ the NSW Dams Safety Committee guidelines on tailings dams (DSC3F), which wasn’t published until June 2012, more than two years after the proponent submitted Knight Piesold’s designs. If the facility meets the NSW requirements incidentally, that needs to be demonstrated and specific criteria referenced. As it stands, the Dargues TSF design would not be approved in Victoria and has not been shown to meet current NSW standards.

Interaction of buried tailings (‘paste fill’) with groundwater via leachate: Mod 1 data claims that leachate from paste fill does not exceed a single drinking water value… miraculous given the composition of the tailings.

Unreliable meteorological data, especially the underestimation of rainfall. Inappropriate ‘averaging’ of rainfall data with stations external to the mine site, and the failure to take into account the effects of climate change on the frequency and intensity of high rainfall events. This further called into question the adequacy of TSF design, including the rather modest freeboard (designed to manage a 1 in 100 year rainfall event before over-topping, based on historical rainfall data) and the absence of a failsafe dam.

The possibility of more frequent and severe drought means that the additional strain on the water table for mining operations (and for at least a decade afterwards) is more likely to cause the already fledgling surface water flows of the Deua River to shrink into a series of stagnant pools…

Lowering of the water table with the mine’s interception of groundwater. This translates to a loss of baseflow to the downstream freshwater system at the rate of up to 12 litres per second (720 litres per minute; 43,200 litres per hour; 1,036,800 litres per day; 7,257,600 litres per week, etc). The offsetting of this water loss with inferior and potentially contaminated water pumped into Majors Creek from dams and historical mine shafts. Degradation of overall water quality in the Deua River.

The effects of high winds blowing dry tailings in particulate form from the mine site. The effect of heavy mists in soaking up exposed contaminants and depositing them in the surrounding environment.

Inadequate sediment and erosion control measures leading to turbidation throughout the catchment (as occurred at least three times in 2013, resulting in prosecution by the EPA). The uncontrolled sediment discharges were accompanied by contamination with a ‘flocculating agent’. A flocculant is a chemical used (in this case, illegally) to bind sediment particles into larger clusters or ‘flocs’ so that, under ideal conditions, they settle at the bottom of sediment dams. However, if released these chemicals can prove toxic to aquatic life. According to one speaker at the PAC, the sediment-flocculant discharges of 2013 killed frogs and fish.

Another possible effect of sediment discharge from the site, whether during or after its operational life, is Eutrophication (meaning ‘well nourish’, also known as hypertrophication). This is the environment’s reaction to an excess of nutrients, such as those carried in run-off from disturbed soil. A freshwater ecosystem, in which the proliferation of life is limited by the natural availability of phosphates, typically reacts to a nutritional over-supply with an algal bloom or noxious growth of water-clouding plant life. This blocks sunlight, killing aquatic plants that depend on photosynthesis. When the algae or other excess vegetation dies, bacteria multiply to effect its decomposition. These bacteria consume oxygen, which turns the water hypoxic (oxygen-deficient). Fish and other aquatic creatures suffocate, the water is rendered unable to support life, and poses a risk to human health.

The incremental expansion or ‘creep’ of the Dargues operation (or future operations in the region) with no final limitations, or a set end date, beyond which no further applications are to be considered. [UPDATE: the mining company, Diversified Minerals, has had their mining lease extended until April 12, 2045, two decades beyond the preceding lease, which was to expire on June 30, 2025].

General distrust of the proponent. The mining company is named as Unity Mining in the application, although the company has recently been bought by PYBAR and is being turned into a subsidiary, Diversified Minerals. Some staff remain from Unity, including the project manager. Deceptions associated with the (now canned) application for cyanide processing include the original promise that it would “never” be introduced, and the attempt to reduce the impression of its toxicity. These and other  complete loss of social license, insofar as it ever existed.

Lack of truly independent, externally funded and ongoing compliance audits. At present, the Proponent effectively monitors its its own compliance with conditions imposed by the EPA, Department of Planning, or Land and Environment Court.

After the meeting, the current owners of the mine (PYBAR) circulated a job advertisement for a ‘Health, Safety and Environment Superintendent’. The job description includes ‘Environmental Compliance and Management… Your role will see you liaising with government agencies to ensure that the mine remains compliant.’ This rather confirms the concern that company intends to monitor and report on its own behaviour. Further, the way that the role is described seems to imply that compliance is a product of the liaison with government, rather than of actual adherence to the company’s approvals, licenses and commitments. Here’s the advertisement: Pybar – Health, Safety, Environment &amp; Community Superintendent

Inadequacy of procedures to alert the public when pollution occurs, or the withholding of information about the occurrence or nature of the pollution (as demonstrated in the sediment and flocculating agent discharges of 2013).

Tailings-laden heavy vehicle movements on unsuitable public roads (to which I would add: the proposed crossing over Spring Creek, between the box cut and the TSF, places on-site tailings trucks directly over the waterway).

The withdrawal of most of the Proponent’s Statement of Commitments, which listed scores of specific pollution control measures. The inadequacy of the  remaining Conditions of Approval to meet the stringency of the abandoned commitments.

The ongoing erosion of the strict conditions and limitations imposed on the Dargues project by the Land and Environment Court Order (February, 2012). The loophole in our environmental law (part 3A, section 75W of the Environmental Planning and Assessment Act [EP&A Act] of 1979 – now repealed) that allows proponents to alter court orders by applying for modification via the Department of Planning and Environment. The misnomer of that department’s title.

The complete and ongoing absence of any detailed consideration of the consequences of a tailings spill (to the environment, human health, or the regional economy) via the foreseeable mechanisms of structural failure of the TSF, or overtopping due to rainfall, or long-term leachate through a time-degraded TSF liner. Naming a ‘consequence category’ with a vague, generic definition concerned mainly with financial & credibility losses to the proponent, and tucked away in an appendix of the Environmental Assessment, does not constitute due consideration.

Inadequacy of the company’s rehabilitation bond. The bond is some 60 million, to be held by the government in case the company reneges on its commitment to properly decommission the mine site at the end of its mining license. This is insufficient to cover (a) the costs of clean-up in the case of major pollution event (to which I would add: effective clean-up is impossible once pollution is entrained downstream; Spring Creek – Majors Creek – Araluen Creek – Deua River – Batemans Marine Park); (b) the long-term economic damage of degrading the Eurobodalla Shire’s primary water supply for generations, whether in reputation or actuality; (c) the certain costs of monitoring and maintaining the Tailings Storage Facility landform for an indefinite period (centuries) after capping and ‘rehabilitation’. Note that the bond will not even contribute toward this, as it will be returned to the proponent after initial ‘rehabilitation’ is complete.

The potential of the Eastern Waste Rock Emplacement (630,000 tonnes of subterranean rock deposited on the surface) to cause acid rock drainage to surface and ground water. The proponent denies this on the basis of certain expert reports raised during the Land and Environment Court action (February 2012), however a speaker suggested that these documents were not conclusive.

Employment of Knight Piesold to engineer the TSF, despite their demonstrated complicity in the Mt Polley tailings spill in Canada, August 2014. Thorough investigation by an Independent Expert Panel (January 2015), and British Columbia’s Ministry of Energy and Mines (August 2015) both conclude that the original design failed to take into proper account the geological foundations on which the Mt Polley TSF was to be built (specifically, a soft layer of glaciolacustrine / GLU / glacial till, into which the embankment suddenly sank before rupturing). Knight Piesold denies all responsibility for the Canadian disaster and has never been held to legal account.

Benefits of the Mine: 80 jobs, which may or may not be filled by local people, and whose contracts will be limited to the operational life of the mine.

Spending of between $3 and $7 million per year in local and regional economies (RTS, p.15). To put this into perspective, the Eurobodalla’s annual budget is $100 million. The economic gain is insignificant compared to the economic risk of polluting the Shire’s primary water source (which would cripple agriculture, tourism, and property value). The mine’s economic injections are also short-term, whereas its waste is an ongoing liability, to be buried at our headwaters forever.

Most of the mine’s capital investment ($10 – $31 million as claimed by the proponent) will go to state and federal governments, along with all taxes and royalties ($1 – $8 million). These amounts are even less significant at the state and national scales. Whereas with clean water and unspoilt beauty, the Eurobodalla/Palerang Shires can contribute to the economy at all scales for generations to come.


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