Inclusion of Faults in Mining and Coal Seam Gas Environmental Risk Assessments

Summary Environmental Impact Assessment Statements (EIS) for Mining and Coal Seam Gas (CSG) projects are generally required to consider the potential hydrological impacts of faults on surface and near-surface groundwater assets. Three distinct end-member geological scenarios and outlines methods for characterising fault-related groundwater flow within a risk assessment context have been proposed ( Murray& Power, 2021 ). This presentation considers the environmental hydrological aspects of risk assessment for mining and CSG developments. Following water resources and environmental risk assessment, we refer to features such as lakes, rivers, groundwater-dependent ecosystems, and valuable aquifers as groundwater assets or simply assets. Damage to a groundwater asset may include (for example) groundwater depletion or changes to the flow regime caused by mining and CSG development-induced pressure changes. Pressure changes may cause increased or decreased flow along pre-existing flow pathways, or cause the activation of new or previously unimportant flow paths. Should this flow be significant enough to degrade the asset, then the flow pathway is called a causal pathway.