Oral Presentation NCGRT/IAH Australasian Groundwater Conference 2019

A golden age for environmental tracers in Australia (361)

Sébastien Lamontagne 1
  1. CSIRO, Adelaide, SA, Australia

Environmental tracers have been an integral component of hydrogeological studies in Australia for decades. However, the stage is now set for an unprecedented level of activity driven by the increased need for water resource assessments, new fields of investigation, and the recent availability of new tracer techniques. In water resource assessments, there is a need for more detailed groundwater system characterisation due to increased scrutiny of existing water allocation plans, resource development proposals, the proposed expansion of irrigation in Northern Australia, and a dwindling resource under climate change. The planned trillion-dollar expansion of the unconventional gas industry in the coming decades will bring an increased focus on the connectivity between deep and shallower geological units and the slower movement of fluids at depth – areas where tracers have many applications. Other national challenges where tracers could see broader use include groundwater contamination, mine site remediation, underground disposal of CO2 and nuclear waste, as well as rising sea levels and its effects on coastal cities and aquifers. The development of a new suite of analytical facilities in Australia to measure stable and radioactive noble gases opens many possibilities for new applications. These tracers have simple input functions, have no chemical reactions and are ideally suited to the evaluation of hydrological connectivity, recharge environments, or addressing the parts of the groundwater-age distribution invisible to other tracers. Despite a recognition of their usefulness, the cost, lack of expertise, and delays in obtaining results are current hurdles for a more effective uptake of tracer techniques by industry. Advanced training tailored to students, policy makers, and industry, coupled with a more robust infrastructure for the timely delivery of tracer analyses are the key ingredients required to enable a golden age for environmental tracers in Australia to blossom.