Table 5.5 Criteria, controls and monitoring to mitigate pathogen hazards in relation to the stages of risk assessment residual risk <10–6 recharge has low risk of (operational) DALYs per person per pathogen contamination year without reliance Exposure to recovered • Confirm residual risk <10–6 on aquifer for water is no greater than • DALYs per person per year Acceptance to the source water used treatment or dilution for water recovered (by criteria for recharge (eg use of 95th project and by any third End use for recycled percentile pathogen • party), based on additional water and environmental numbers); or in the Entry-level data collection if dependent values of aquifer exclude absence of data, use assessment on treatment in the aquifer drinking water values from other and guidelinesa to simplified determine DALYs assessment Maximal and precommissioning residual Residual risk risk assessment Source • assessment water for Source water has a • water assessment Preventive protection measures Removal using • treatment processes Residence time in n • the soil and/or aquifer Reducing exposure • • As per precommissioning residual risk S • that the process control Validation and operational monitoring monitoring correlate with pathogen inactivation; provide ongoing assurances that the attenuation zone is operating effectively, and that water of an appropriate quality is being produced. This includes setting critical limits to differentiate between acceptable and unacceptable performance. na na Monitor pathogens or • Verification indicator organisms in monitoring recovered water and in observation wells at edge of attenuation zone n Achieve the specified • log removal to achieve acceptance criteriab n • t
Table 5.5 Criteria, controls and monitoring to mitigate pathogen hazards in relation to the stages of risk assessment Acceptance criteria Entry-level assessment and simplified assessment • Source water for recharge has low risk of pathogen contamination • Exposure to recovered water is no greater than to the source water used for recharge • End use for recycled water and environmental values of aquifer exclude drinking water Maximal and precommissioning residual risk assessment • Source water has a residual risk <10–6 DALYs per person per year without reliance on aquifer for treatment or dilution (eg use of 95th percentile pathogen numbers); or in the absence of data, use values from other guidelinesa to determine DALYs Residual risk assessment (operational) • Confirm residual risk <10–6 DALYs per person per year for water recovered (by project and by any third party), based on additional data collection if dependent on treatment in the aquifer Preventive measures • water protection • Removal using treatment processes • Residence time in the soil and/or aquifer • Reducing exposure • As per precommissioning residual risk assessment Validation monitoring Verification monitoring • that the process control and operational monitoring correlate with pathogen inactivation; provide ongoing assurances that the attenuation zone is operating effectively, and that water of an appropriate quality is being produced. This includes setting critical limits to differentiate between acceptable and unacceptable performance. na na • Monitor pathogens or indicator organisms in recovered water and in observation wells at edge of attenuation zone • Achieve the specified log removal to achieve acceptance criteriab t n n n S
water-recycling-guidelines-mar-24.docx