Risk assessment frameworks for MAR schemes in the UK

Managed aquifer recharge (MAR) provides a sustainable method to store large volumes of water. However, uncertainties around the associated risks, initial costs and regulatory regime are key influences on its development in the UK. This paper reports a critical review of available risk management frameworks as a first step towards the development of an assessment framework suitable for MAR schemes in the UK. Classification of risks across the MAR process involved deconstructing the process into functional elements; pre-treatment, recharge, storage, recovery, and post-treatment prior to final use, with each element presenting a range of risks to different receptors. An initial listing of seven potential frameworks were reduced to three (hazard and critical control point analysis, the world health organisation’s water safety plans and the Australian guidelines for water recycling using MAR) for detailed assessment. Although the hazard and critical control point analysis and the water safety plans may be adapted for use in MAR, they do not provide specific guidance for potential risks associated with aquifer recharge schemes. Furthermore, neither of them adequately addresses the risks associated with the recharge, storage and recovery elements of a scheme. The Australian guidelines provide guidance specific to MAR and are particularly effective in considering risk to these elements. The main conclusion is that although the Australian guidelines focus on potential hazards and might thereby not be suitable for identifying more process oriented considerations, they do constitute a robust basis for developing a framework for risk management for MAR schemes in the UK.