Mid-term report summary

FRAME project mid-term summary

The practice of the purposeful addition of highly treated wastewater after passage through an environmental buffer to a drinking water supply is referred to as planned or intentional indirect potable reuse (IPR). IPR provides options to maintain sufficient water quantities for communities in the future. However, there is concern regarding potential adverse environmental and human health effects and the application of IPR technologies is still limited by a heightened risk perception and regulatory constraints.

The FRAME project aims towards novel approaches to assess and manage IPR by: i) the development of an overarching evaluation and monitoring scheme for IPR processes including sound analytical and modelling approaches, toxicological assessment and public health-relevant microbiological parameters; ii) design and testing of reliable and cost-effective treatment strategies and novel treatment approaches; iii) providing water utilities and agencies as well as regional, national and EU authorities with a meaningful and reliable decision support tool for future investments and implementations, supporting decisions on how IPR practices can be embedded in the EU legislative framework.

For the application of comprehensive monitoring strategies, analytical methods for a suite of chemical, biological and toxicological parameters have been developed. For the analysis of CECs these include several multi-residue, sensitive mass-spectrometry-based analytical methods for the determination of up to 272 individual CECs as well as methods for the detection/identification of unknown contaminants (non-target methods). The application of advanced treatment options in a multiple-barrier approach is applied at laboratory- and full-scale to test novel and effective treatment options, specifically to improve the removal of CECs, inactivation of pathogens and improvement of other health-related parameters. Modelling tools are implemented to test the performance of novel treatment combinations and are coupled with transport modelling tools to describe the fate of CECs and pathogens in different IPR scenarios. The information gained from experiments and modelling is made accessible via Decision Support Tools, which allow decision makers to estimate IPR performance based on modelling results. The Decision Support Tools are part of a wider communication and decision support strategy to provide guidance for regulation and compliance needs as well as prioritisation of abatement options.

Results of full-scale monitoring campaigns indicate the benefits of short-term SAT as a cost-effective post-treatment option which can be incorporated into a multi-barrier IPR approach. Advanced analytical methodologies allow for testing of IPR processes to go beyond state-of-the-art and broaden the scope of monitored parameters, ultimately with the goal of decreasing human-health related risks of IPR implementation.

Detailed fate studies into CECs during water treatment processes investigated the transformation to previously unknown transformation products (TPs). Based on modelling approaches, the toxicological relevance of several TPs were found to be higher than that of the precursor CECs. The results indicate the importance of including the assessment of TP formation in an overall evaluation of treatment processes.

The application of non-target analysis approaches enabled the identification of previously unknown contaminants in water. This demonstrates the use of non-target analysis to monitor IPR for yet to be identified contaminants, to test the resilience of processes to unexpected inputs and opens discussions for future regulatory options.