Aquifers Recharge and Contamination by Leaking Sewers - ARCLeakS

The ARCLeakS (Aquifers Recharge and Contamination by Leaking Sewers) project aims to fill the existing theoretical and practical knowledge gap on the fate of contaminants originating from leaking sewers in the subsurface of urban environments. The objective of the project is to gain additional knowledge to support managing authorities, water companies, industries, practitioners, and researchers to better identify and quantify urban aquifers physical and chemical alterations, so as to improve the management of the available water resource and to prevent adverse effects on natural resources, the built environment, and human health, like soil and groundwater contamination, flooding of underground spaces, diffusion of pathogens, etc. Indeed, urban aquifers recharge and contamination from water utilities is usually inferred from water balance calculations at the catchment scale, not always supported by piezometry and chemical signature analysis. However, the complexity of urban environments and the scarcity of data make it difficult to discriminate the effects of leaking sewers among the numerous potential sources of recharge and contamination that might exist in urban areas (e.g., other leaking water utilities, stormwater infiltration facilities, irrigation of gardens and parks, infiltration from paved surfaces, septic tanks, etc.). Hence, these analyses can be affected by a high degree of uncertainty and there is a risk that the amount of water leaked from water utilities simply becomes a calibration parameter to find closure for water balance calculations. Therefore, the project aims to better understand how wastewater and stormwater leaked from sewers interact with the numerous anthropogenic features present in the subsurface with the aid of high-resolution modeling of both surface and subsurface related phenomena. Predicting the migration pathways of wastewater and stormwater in the subsurface can potentially lead to improved monitoring and remedial actions for the management of existing utilities and for the protection of urban groundwater. With this information, the location of piezometers and water quality sensors could be optimized to better monitor and interpret pressure and quality alterations within urban aquifers that could help locate and quantify leaks, thus enabling faster and more accurate interventions (e.g., soil/groundwater treatment and remediation, pipes repair and rehabilitation). The expected result is to obtain useful additional knowledge and to bridge this towards a wide spectrum of stakeholders, from managing authorities to water companies, industries and decision makers, as well as to practitioners and researchers.