Another key scientific report has been released on potential impacts of developing an onshore gas industry in the NT's Beetaloo Basin.
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This $35.4 million program is assessing the potential environmental and water-related impacts of future shale and tight gas development in three onshore geological basins.
The Federal Government's Geological and Bioregional Assessments Program is assessing the potential impacts of shale and tight gas development in the Cooper Basin in north-east South Australia through to south-west Queensland and also the Isa Superbasin in Queensland.
These studies are seen as necessary to provide baseline data and risk assessments before any production can be approved.
The scientific studies are being conducted by CSIRO and Geoscience Australia, supported by the Bureau of Meteorology and managed by the Department Agriculture, Water and the Environment.
Environment Minister Sussan Ley and Resources Minister Keith Pitt released baseline analysis reports from Stage Two of the Geological and Bioregional Assessment Program yesterday.
Chief of Minerals, Energy and Groundwater, Dr Andrew Heap, said Geoscience Australia's work has been a major part of the program.
"Geoscience Australia is proud to be part of this joint-agency initiative which enables industry to responsibly develop unconventional gas resources to supply the East Coast Gas Market," Dr Heap said.
"Our comprehensive analysis of the available data has led to the first integrated interpretation combining the regional geology, unconventional gas prospectivity and hydrogeological systems of these three basins.
"This work, which is detailed in supporting technical reports, included the interpretation of satellite-derived datasets to evaluate surface water and groundwater interactions; the creation of new regional-scale unconventional gas prospectivity maps; and the development of hydrogeological systems models to better understand natural processes and components of each region.
"These new scientific insights are fundamental to ensuring shale and tight gas operations can be appropriately managed to support governments, industry and communities to better coordinate resource management for the benefit of the economy and the natural systems that surround these prospective regions.
"For example, Stage Two of the assessment has identified the groundwater resources in all three regions and how they are currently used to support local water users and the environment. It also identifies causal pathways which describe the chain of events that may link unconventional gas development with potential impacts on water and the environment.
"We also identified gaps in knowledge that will help to guide the final stage of the program, where we will further investigate groundwater recharge processes for the Beetaloo Sub-Basin, along with hydrological connections between shallow groundwater systems that overlie deep unconventional gas resources in the Cooper Basin.
"Thorough field studies are also being undertaken and results will be released in 2021.
"The information, data and analysis completed for these basins supports industry to meet the highest possible environmental standards for shale gas activities, which are worth an estimated $9.1 billion in the Beetaloo alone."
The Geological and Bioregional Assessment Program comprises a series of independent scientific studies undertaken by Geoscience Australia and CSIRO, supported by the Bureau of Meteorology and managed by the Department of Agriculture, Water and the Environment.
The reports and more information about the three stages of the program is available at the Geological and Bioregional Assessments Program's website.
The Beetaloo region covers an area of about 28,000 square kilometres.
This second of what is expected to be three reports, found the Beetaloo includes a substantial proportion of the Cambrian Limestone Aquifer, the principal water resource in the region which extends to Katherine.
The region is sparsely populated, with Daly Waters and Elliott the most populated settlements in the region.
The Beetaloo Sub-basin is one of the most prospective areas for shale gas in Australia, as well as having potential for liquid hydrocarbons, the report explained.
Most streams in the region are ephemeral and only flow in response to wet season rains.
Groundwater from the region supports the Roper River and important wetlands such as Mataranka Thermal Pools and Limmen Bight (Port Roper) Tidal Wetlands System.
"If contaminants (e.g. chemical spills) were to intercept the Cambrian Limestone Aquifer then potentially they could be transported and dispersed relatively quickly by large pathways," the report found.
For instance, a 2005 study showed groundwater flow velocities of up to 1250 m/day have been noted in the aquifer in the vicinity of Katherine.
More reading: Greenhouse gas emissions in the Beetaloo are plotted.
Researchers found there are about 1153 stock and domestic bores in the "extended" Beetaloo region mainly used for cattle.
"There are two potential groundwater sources to supply future demand for use in drilling and hydraulic fracturing operations for the unconventional petroleum industry - unused allocations and treated formation and produced water," the report found.
Hydraulic fracturing of a well would require approximately 10 to 20 megalitres of water for ten-stage fracturing operations.
The Pepper scientific inquiry estimated about 1000 to 1200 unconventional wells will be developed over the next 25 years.
Researchers assessed 116 chemicals used between 2011 and 2016 for drilling and hydraulic fracturing at shale, tight and deep coal gas operations.
About one-third (42 chemicals) were of "low concern" and pose minimal risk to aquatic ecosystems.
A further 33 chemicals were of "potentially high concern" and 41 were of "potential concern".
The identified chemicals of potential concern and potentially high concern would require further site-specific quantitative chemical assessments to be performed to determine risks from specific gas developments to aquatic ecosystems.
"Springs have not been identified in the Beetaloo region. However, numerous springs occur to the north of the Beetaloo region, where significant groundwater discharge occurs from Cambrian aquifers to rivers and wetlands, such as Mataranka Thermal Pools and Roper River.
"Hydrochemistry and dissolved gas concentrations from the CLA (Cambrian) provide some evidence of existing hydrological connectivity between deep and shallow system components.," the report states.
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