An assessment of micro-organic pollutants in groundwater across England and Wales

In the last few decades there has been a growing interest in the occurrence of micro-organic (MO) contaminants in the terrestrial and aquatic environment, and in their environmental fate and potential toxicity. A large variety of MOs are used in huge quantities for a range of purposes including arable agriculture, industrial manufacturing processes, as well as human and animal healthcare. Improvements in analytical techniques have allowed identification of organic compounds at low concentrations previously undetected in the aqueous environment. The contamination of groundwater resources by MOs is a growing concern and relatively poorly understood compared to other freshwater resources. Of particular concern are newly ‘emerging contaminants’ such as pharmaceuticals and life-style compounds, particularly those with potential endocrine disrupting properties. While groundwater often has a high degree of protection from pollution due to physical, chemical and biological attenuation processes in the subsurface compared to surface aquatic environments, trace concentrations of a large range of compounds are still detected in groundwater. This study provides the first national scale assessment of micro-organic compounds in groundwater in England and Wales by analysing a national dataset to determine the relative occurrence and detected concentrations of different groups of compounds and aims to determine relationships with different land-use, aquifer types and groundwater vulnerability. MOs found included caffeine, DEET, anti-microbial agents and pharmaceuticals as well as a range of legacy contaminants including chlorinated solvents and THMs, petroleum hydrocarbons, pesticides and other industrial compounds