Application of the Australian Guidelines for Water Recycling Phase 2: Managed aquifer recharge to Perry Lakes example

[摘要] Executive summary:This is a case study of an environmental risk assessment for a managed aquifer recharge (MAR) project that considers the environmental values of aquatic ecosystems in the context of replenishing an aquifer with secondary treated wastewater. This report was commissioned by the Department of Water to assist future MAR proponents in undertaking environmental risk assessments in line with the Australian Guidelines for Water Recycling (AGWR) Phase 2 – Managed Aquifer Recharge (2009), particularly those that involve similar issues. It is intended to demonstrate the process and to explain how to interpret sections of the guidelines pertaining to environmental risks and to provide a step by step guide to regulators and future proponents on the environmental risk assessment requirements of the AGWR.This report identifies data requirements and knowledge gaps that limit meaningful application of the guidelines and future work required to address these deficiencies.The Australian Guidelines for Water Recycling: Phase 2, Managed Aquifer Recharge were published on the website of the Environmental Protection and Heritage Council (NRMMC-EPHC-NHMRC, 2009) in August 2009 as part of Phase 2 of the Australian Guidelines for Water Recycling (http://www.ephc.gov.au/taxonomy/term/39). The guidelines pertain to different sources of water, including treated sewage, stormwater, treated drinking water, and natural waters.An environmental risk assessment was conducted based on a preliminary design proposal for managed aquifer recharge (MAR) via infiltration at the Perry Lakes. The Perry Lakes Reserve is in the Town of Cambridge in the suburb of Floreat, Western Australia. The site consists of a series of shallow wetlands above an unconfined aquifer composed of sand overlying limestone. The MAR proposal is to produce a water table mound by recharging the aquifer with secondary treated wastewater using a series of shallow infiltration galleries. The water table mound would serve as a partial hydraulic dam that would raise the water table beneath East and West Lakes in Perry Lakes Reserve. The intent is for recharged water to not enter the lakes. The proposal also involves irrigating the parkland around the lakes, using existing groundwater abstraction bores which are slotted towards the base of the aquifer.The Perry Lakes project was selected as sufficient work had been completed to date to apply stages 1 (Entry level risk assessment) and 2 (Investigations and maximal risk assessment) of the AGWR. Further stages, such as identifying preventative measures are not part of this report. A public health risk assessment is also needed and would be assessed by the Department of Health, but was not commissioned as part of this report.

[发布日期] 2011-06-15 [发布机构] CSIRO

[学科分类] 地球科学(综合)