Table 5.13 Criteria, controls and monitoring to mitigate pressure, flow or volume-related hazards in confined and semiconfined aquifers in relation to the stages of risk assessment downward leakage is models negligible predict Predicted land subsidence • defined is negligible maximum and Acceptance Residual risk assessment minimum criteria (operational) heads in injection Entry-level well, to be assessment As per achieved by • and precommissioning pump simplified residual risk assessment, selection assessment with confirmation, based and Analytical on field and laboratory • placement models measurements, Acceptable • predict no informing predicted other wells to hydrogeological and maximum be and geotechnical evaluations artesian minimum of uncertainties identified Wells heads in in precommissioning • constructed other wells residual risk assessment and as a result of To include • completed operation, quantified criteria according to (eg bursting with respect well pressure, subsidence, to completion and head changes in aquitard – permit observation and other protection wells) subsidence – Maximal Modelling and trials • leakage losses reveal no adverse effects and – on other head and – aquifers or water-quality connected residual changes in ecosystems risk other assessment aquifers (from calibrated Calibrated • model of model) No wells in injection • zone with large and head changes recovery intersect the well rates target aquifer, of flow, have cumulative multiple recharge completions or and are known to be discharge poorly volumes, completed and Recharged pressures • water is for confined to proposed target storage zone and trial predicted (Stage 3) upward and •
Table 5.13 Criteria, controls and monitoring to mitigate pressure, flow or volume-related hazards in confined and semiconfined aquifers in relation to the stages of risk assessment Acceptance criteria Entry-level assessment and simplified assessment • Analytical models predict no other wells to be artesian • Wells constructed and completed according to well completion permit Maximal and residual risk assessment • Calibrated model of injection and recovery well rates of flow, cumulative recharge and discharge volumes, and pressures for proposed trial (Stage 3) • models predict defined maximum and minimum heads in injection well, to be achieved by pump selection and placement • Acceptable predicted maximum and minimum heads in other wells as a result of operation, with respect to – aquitard protection – subsidence – leakage losses – head and water-quality changes in other aquifers (from calibrated model) • No wells in zone with large head changes intersect the target aquifer, have multiple completions or are known to be poorly completed • Recharged water is confined to target storage zone and predicted upward and downward leakage is negligible • Predicted land subsidence is negligible Residual risk assessment (operational) • As per precommissioning residual risk assessment, with confirmation, based on field and laboratory measurements, informing hydrogeological and geotechnical evaluations of uncertainties identified in precommissioning residual risk assessment • To include quantified criteria (eg bursting pressure, subsidence, and head changes in observation and other wells) • Modelling and trials reveal no adverse effects on other aquifers or connected ecosystems
water-recycling-guidelines-mar-24.docx