Water quality is key to public and environmental health. One of the hazards that threatens water quality is the presence and/or release of contaminants of emerging concerns (CECs), such as pharmaceuticals, personal care product ingredients, pesticides, and industrial effluents, in the water cycle. A promising and cost-effective approach for efficient CECs removal is to enhance existing biological sand- and active carbon filtration at waste- and drinking water treatment plants (WWTP, DWTP). Biodegradation of CECs has been observed in these filtration processes, but the conditions that select for CECs biodegradation and the pathways involved are poorly understood, preventing further optimization of existing filtration processes for efficient CECs removal and mineralization. The overall objective of the project is to better understand and improve biodegradation of priority hydrophilic and persistent CECs in existing sand and active carbon filtration at WWTPs and DWTPs.