Groundwater supports many communities and industries and provides water for environmental assets around Australia, including rivers, springs, wetlands and groundwater-dependent ecosystems (GDEs). Groundwater, accounts for over 30% of Australia’s total water consumption (NWC 2008) with uses including drinking, irrigation, stock supply and bottling. The demand for groundwater is steadily growing, as Australia’s industrial and agricultural development increases. Knowledge of aquifers and fundamental groundwater processes are important for managing the quantity, quality and sustainability of this resource. Monitoring groundwater by analysing its chemical constituents is integral to understanding groundwater systems and aids effective management. Sampling and analysing groundwater on a regular basis provides a useful tool to understand and monitor changes to groundwater systems. Depending on the purpose of monitoring, a comprehensive, fit-for-purpose, suite of parameters should be collected and tested. Groundwater sampling requires specialised methods and approaches to acquire samples for analysis that represent the in-situ groundwater hydrogeochemical and hydrogeological conditions. Multiple government agencies have produced guidelines to address specific groundwater issues, including: groundwater sampling (Jiwan & Gates, 1992; Rayment & Poplawski, 1992; Hill, 2007; EPA Victoria, 2022; ANSTO; and NMI); groundwater quality sampling in the Murray-Darling Basin (MDBC 1997); groundwater monitoring for community groups (Waterwatch 2005); and sampling for contaminated sites (AWRC, 1991). Groundwater sampling and analysis is a tool that can be used for multiple geoscientific purposes, including: groundwater resource assessment; management and monitoring; carbon capture and storage; mineral exploration; geothermal energy; and energy and resource industries. This document provides a comprehensive guide, applicable to a range of geoscientific disciplines, that draws together information on drilling methods, bore construction, sampling equipment and sampling methods for groundwater analysis. This guide contains standard groundwater sampling protocols, also known as standard operating procedures (SOPs), commonly used by Geoscience Australia (GA) over the last decade. These protocols aim to provide consistency for the acquisition of accurate, repeatable and comparable groundwater datasets and provides confidence in their analysis and interpretation.

<div>The recent Musgrave Palaeovalley Project set out to map the extent and characterise the palaeovalley architecture of several of these Cenozoic features that overlie the Musgrave Province in central Australia. To effectively model the palaeovalley architecture of these features we collected approximately 20 000 line km of new Airborne Electromagnetics (AEM) and combined it with an array of existing AEM datasets, including AusAEM and high resolution mineral exploration surveys. These older surveys were reprocessed and reinverted to produce a consistent and reliable interpretation throughout. Utilising surface geology and lithology logs to constrain this data set, we mapped the interface between Cenozoic sediments and underlying pre-Cenozoic rocks, producing a continuous three-dimensional model of this boundary throughout the study area.</div><div><br></div><div>Our three-dimensional model enhances the understanding of the West Musgrave palaeovalley system, redefining palaeovalley extents, revealing previously unmapped palaeovalleys and identifying areas with significant accumulations of Cenozoic sediments. This methodology was also extremely useful for investigating palaeovalley geometry, revealing southerly flowpaths consistent with regional expectations but also highlighting areas of palaeovalley deformation where neo tectonic forces have acted to alter historical flow regimes. This deformation is likely to cause groundwater compartmentalisation, mounding or connect different aquifer units. Presented at the 2024 Australian Society of Exploration Geophysicists (ASEG) Discover Symposium

<div>This was the last of five presentations held on 31 July 2023 as part of the National Groundwater Systems Workshop. Towards developing a 3D hydrogeological framework for Australia: A common chronostratigraphic framework for aquifers&nbsp;</div><div><br></div>

<div>Groundwater is a finite and largely hidden resource. Enhancing scientific understanding of groundwater systems improves decisions about its planning, allocation and use. This benefits all Australians through improved water management.</div><div>Australia’s groundwater resources underpin billions of dollars of economic activity, provide safe and reliable drinking water for millions of people, and sustain life and cultural values across the country. Sustainably managing our critical groundwater resources is vital to improving water security and protecting the environment.</div><div>Geoscience Australia and the Commonwealth Scientific and Industrial Research Organisation (CSIRO) collaborate on initiatives funded by the Australian Government. We work together to deliver innovative solutions to nationally significant issues affecting Australia’s groundwater resources.</div><div>With world‑class expertise and facilities, we are at the forefront of groundwater science. Our combined hydrogeological capabilities are best applied to regional and national-scale challenges that extend beyond the remit of individual jurisdictions or private industry.</div><div>This publication highlights the scientific approaches, technologies, and methods that we apply to better understand and characterise Australia’s groundwater and includes case studies that demonstrate the unique value of our collaboration.</div><div><br></div>

<div>This report details results and methodology from two hydrochemistry sampling programs performed as part of Geoscience Australia’s Musgrave Palaeovalley Project. The Musgrave Palaeovalley Project is a data acquisition and scientific investigation program based around the central west of Australia. It is aimed at investigating groundwater processes and resources within the Cenozoic fill and palaeovalleys of the region. This project, and many others, have been performed as part of the Exploring for the Future (EFTF) program, an eight-year, $225 million Australian Government funded geoscience data and precompetitive information acquisition program.</div><div>Data released here is from 18 bores sampled for groundwater and tested for a range of analytes including field parameters, major and minor elements, isotopes and trace gases. The sampling methods, quality assurance/quality control procedures, analytical methods and results are included in this report.</div>

<div>Reliable water availability is critical to supporting communities and industries such as mining, agriculture and tourism. In remote and arid areas such as in the Officer – Musgrave region of central Australia, groundwater is the only viable source of water for human and environmental use. Groundwater systems in remote regions such as the Musgrave Province are poorly understood due to sparse geoscientific data and few detailed scientific investigations. The Musgrave palaeovalley module will improve palaeovalley groundwater system understanding in the Musgrave Province and adjacent basins to identify potential water sources for communities in the region. This report summarises the state of knowledge for the region on the landscape, population, water use, geology and groundwater systems. An analysis of the current and potential future water needs under different development scenarios captures information on how water is used in an area covering three jurisdictions and several potentially competing land uses.</div><div>The Musgrave Palaeovalley study area is generally flat, low-lying desert country. The Musgrave, Petermann, Mann and Warburton ranges in the centre of the area are a significant change in elevation and surface materials, comprising rocky hills, slopes and mountains with up to 800&nbsp;m of relief above the sand plains. Vegetation is generally bare or sparse, with isolated pockets of grassy or woody shrub lands. Soils are typically Tenosols, Rudosols and Kandosols.</div><div><br></div><div>There are four main hydrogeological systems in the study area. These are the fractured and basement rocks, local Quaternary sediments regional sedimentary basins and palaeovalley aquifers. These systems are likely to be hydraulically connected. Within palaeovalleys, three main hydrostratigraphic units occur. The upper Garford Formation is a sandy unconfined aquifer with a clay rich base (lower Garford Formation) which acts as a partial aquitard where present. The Pidinga Formation represents a coarser sandy or gravelly channel base, which is partly confined by the lower Garford Formation aquitard. The aquifers are likely to be hydraulically connected on a regional scale. Further to the west, equivalent units are identified and named in palaeovalley systems on the Yilgarn Craton. </div><div><br></div><div>Groundwater is recharged by episodic, high-intensity rainfall events and mostly discharges via evapotranspiration. Recharge is higher around the ranges, and lower over the flatter sand plains. Palaeovalley aquifers likely receive some groundwater inflow from underlying basin systems and fractured rock systems. Regional groundwater movement is topographically controlled, moving from the ranges towards surrounding areas of lower elevation. In some palaeovalleys groundwater discharges at playa lakes. Water table gradients are very low. More groundwater isotope and tracer data is required to understand potential connectivity between basin, fractured rock and palaeovalley systems.</div><div>Groundwater quality is brackish to saline, although pockets of fresher groundwater occur close to recharge areas and within the deeper and coarse-grained Garford Formation. Groundwater resources generally require treatment prior to use Most groundwater in the region is suitable for stock use. </div><div><br></div><div>Existing palaeovalley mapping is restricted to inferring extents based on landscape position and mapped surface materials. Utilising higher resolution digital elevation models and more recently acquired remotely sensed data will refine mapped palaeovalley extents. Improving the modelling of the distribution and depth of palaeovalleys in greater detail across the region is best aided through interpretation of airborne electromagnetic (AEM) data.</div><div>Based on the successes of integrating AEM with other geoscientific data in South Australia, we have acquired 25,109 line km of new AEM across the WA and NT parts of our study area. We will integrate this data with reprocessed and inverted publicly available AEM data, existing borehole information, existing and newly acquired hydrochemical data, and new surface magnetic resonance data to model the three dimensional distribution of palaeovalleys in the study area. We will use these models and data as the basis for conceptualising the hydrogeology of the palaeovalley systems, and provide information back to local communities and decision-makers to inform water management decisions. The data will also provide valuable precompetitive information for future economic development in the region.</div><div><br></div>

<div>The Kati Thanda – Lake Eyre Basin (KT–LEB) covers about 1.2 million square kilometres of outback Australia. Although the basin is sparsely populated and relatively undeveloped it hosts nationally significant environmental and cultural heritage, including unique desert rivers, sweeping arid landscapes, and clusters of major artesian springs. The basin experiences climatic extremes that intermittently cycle between prolonged droughts and massive inland floods, with groundwater resources playing a critical role in supporting the many communities, industries, ecological systems, and thriving First Nations culture of the KT–LEB.</div><div><br></div><div>As part of Geoscience Australia’s National Groundwater Systems Project (in the Exploring for the Future Program) this report brings together contemporary data and information relevant to understanding the regional geology, hydrogeology and groundwater systems of Cenozoic rocks and sediments of the KT–LEB. This work represents the first whole-of-basin assessment into these vitally important shallow groundwater resources, which have previously received far less scientific attention than the deeper groundwater systems of the underlying Eromanga Basin (part of the Great Artesian Basin). The new knowledge and insights about the geology and hydrogeology of the basin generated by this study will benefit the many users of groundwater within the region and will help to improve sustainable management and use of groundwater resources across the KT–LEB.</div><div><br></div>

This was the first of five presentations held on 31 July 2023 as part of the National Groundwater Systems Workshop - A clear and consistent inventory of knowledge about Australia’s major hydrogeological provinces.

<div>Geoscience Australia, in partnership with Commonwealth, State and Territory governments is delivering national and regional groundwater investigations through the Exploring for the Future (EFTF) Program to support water management decisions. Geoscience Australia’s groundwater studies apply innovative geoscience tools and robust geoscientific workflows to increase knowledge and understanding of groundwater systems and assessment of groundwater resource potential for economies, communities and the environment.&nbsp;</div> This presentation was given at the 2022 Australasian Groundwater Conference 21-23 November (https://agc2022.com.au/)

This was the third of five presentations held on 31 July 2023 as part of the National Groundwater Systems Workshop - WaMSTeC: Water Monitoring and Standardisation Technical Committee National Industry Guidelines for hydrometric monitoring WaMSTeC GUIDELINE REVISIONS UPDATE FOR GROUNDWATER COMPONENTS: GROUNDWATER SUBCOMMITTEE