Exclusive : Expert involved in first assessment of NSW coalmine says government approval before a detailed water management plan is ‘backwards’

Uncertainty around the Shenhua Watermark mega-mine’s effect on underground water creates “huge risks” and “is always open to creating irreversible impacts”, according to a former member of the Independent Expert Scientific Committee (IESC).



Jim McDonald, who served as a IESC member from 2012 to 2014 and was involved in the first assessment of the Watermark mine on the Liverpool Plains, described the government process of providing a water trigger approval before a detailed water plan is submitted as “backwards”.

The environment minister, Greg Hunt, has approved – with conditions – the $1.2bn open-cut coalmine on a ridge above prime agricultural land after the second IESC assessment of the Watermark mine. The conditions include the requirement to stop work if agricultural water supplies are affected and to replace any water loss.

Shenhua has yet to present a full water management plan but Hunt has promised to refer the water plan back to the expert committee for review – in a first for the IESC. While the federal government can approve the project under the federal water trigger, the NSW government has the final development decision over whether the Watermark mine goes ahead.

“Whilst minister Hunt has done a good thing in seeking [IESC] advice on the water management plan, the process is still backwards and the question has to be asked – if the foundations are wrong or uncertain in the first place, it will take an extraordinary water management plan to provide confidence, including the determination of the triggers that will be designed to stop harmful or irreversible impacts,” McDonald said.

“Dealing with uncertainty as you go along with groundwater, at such scale as this, creates huge risks and is always open to creating irreversible impacts. This is still an analysis of risk and the modelling is not a statement of fact as some claim. The IESC advice portrays these risks and uncertainties.”



The controversial Chinese state-owned mine, 25km from Gunnedah and west of Breeza in northern NSW is expected to deliver Shenhua up to 10m tonnes of coal every year for up to 30 years. The mine had divided the community, with critics concerned over whether it could affect the surface water and groundwater aquifers which farmers use to irrigate crops on the Liverpool Plains, and on which towns such as Gunnedah rely for their water supplies.



The mine is next to the Mooki river, which is a major tributary of the Namoi catchment and the disturbance area for the proposed project covers 4,084 hectares.



The minister based his decision on the second IESC assessment, although it raised some doubts about surface, groundwater monitoring and management responses due to lack of information.

“The key potential impact associated with the proposed project is change to groundwater pressure and/or level within the Upper Namoi Alluvium groundwater resource,” the advice says.

The IESC assessment said the key matters which still need to be addressed by Shenhua include:

a targeted monitoring program



finer-scale numerical groundwater modelling



identification and assessment of potential impacts to water dependent ecosystems



assessment of local-scale cumulative impacts



long-term impacts associated with the final landform



While McDonald welcomed the minister’s commitment to allow the IESC to review the Shenhua water management plan, he warned data from water modelling, such as that assessed by the committee, was not without its “faults”.



“Models are becoming more sophisticated and knowledgeable however they are not without their faults and all models are made from objective and subjective assumptions and data,” he said.

“Objective data generally comes from monitoring, drilling, etc. Subjective data comes from expertise and the amount of money available to gather objective data.”

Shenhua Watermark project manager Paul Jackson said the company had never shied away from scrutiny of the project, which had been “validated at every stage of the process”.

“The minister and the IESC have both confirmed impacts on groundwater will be negligible and can be managed during operations with strict conditions,” said Jackson.

“We are confident management plans can be developed which comply with the strict operating conditions and satisfy the IESC and minister.”

But McDonald said he was concerned at comments from Jackson on Triple J that “the overburden from the west pit fills in the south pit and by nature of that it means that there won’t be any final void near the black soil plains and that also recharges the aquifers over the longer term”.

McDonald believes Jackson’s comments suggest there is connectivity between the mine and the aquifers, creating the possibility of contamination and unknown water loss.

“The first issue, that has already been identified by the IESC – that as rain moves through the overburden that is infilled into the pit [it] will liberate chemicals from the disturbed rock,” said McDonald. “These dissolved chemicals will then move with the water, and as Mr Jackson says ‘recharges the aquifers over the longer term,” said McDonald.

“Second, the logical progression of what Mr Jackson said forms the highest risk as outlined by all from the beginning.

“If the water in the pits will recharge the aquifers over the longer term it means that there must be a connection from the pits to the aquifers for this to occur.



“Conversely, if that connection is there after the mine, it must be there before the mine, allowing water to move out of the aquifers into the pits if there is a differential pressure head, and as we know there will be due to a height difference.”

McDonald is a farmer and former chair of the Namoi Catchment Management Authority, member of the Namoi Groundwater Ministerial Taskforce and the NSW Groundwater Adjustment Advisory Committee.

Jackson said Shenhua would develop a number of operating and management plans by the end of the year which will “demonstrate how the company will comply with the strict operating conditions imposed by both the NSW and commonwealth governments”.

“Many of these plans must be approved by the commonwealth minister before any works can commence,” he said.