Emerging contaminants in groundwater

The term ‘emerging contaminants’ (ECs) is used to cover not only newly developed compounds but also includes newly discovered compounds in the environment (often due to analytical developments), and compounds that have been recently categorised as contaminants. ECs include a huge array of different compounds (and their metabolites) that are used by society for a range of purposes and include; pharmaceuticals, pesticides, personal care products, veterinary medicines, engineered nano-materials, food additives to list just a few large groups. There is a paucity of information on their occurrence and fate in the aquatic environment, particularly with respect to contamination of groundwater resources. This paper presents an overview of the sources and pathways for EC contamination in groundwater and reviews results on the occurrence of key ECs in groundwater, including case studies from Europe and North America. Data from the UK Environment Agency’s monitoring programme for organic pollutants indicates that the most frequently detected compounds are hydrocarbons, triazine herbicides, chlorinated solvents and their degradation products, THMs, caffeine, DEET, bisphenol A and tributyl phosphate. ECs detected include a limited number of pesticide metabolites, as well as the pharmaceuticals carbamazepine, triclosan and the parabens, caffeine, nicotine, food additives and alkyl phosphates.