Classification of Hazardous and Non-Hazardous Substances in Groundwater

The European Communities Environmental Objectives (Groundwater) Regulations, 2010 (S.I. 9 of 2010) establish a new strengthened regime for the protection of groundwater in line with the requirements of the Water Framework Directive (2000/60/EC) and the Groundwater Directive (2006/118/EC). The Regulations indicate the Environmental Protection Agency should identify and publish a list of substances which are to be considered hazardous or non-hazardous and which the Agency considers to present an existing or potential risk of pollution. The initial list of hazardous and non-hazardous substances must be accompanied by a report that sets out the basis for the Agency’s determination in relation to the substances therein. The Agency shall, as it considers necessary, periodically review and publish updated or amended lists of hazardous and non-hazardous substances, and shall undertake any such consultation it considers necessary for the determination of hazardous and non-hazardous substances.

The Regulations state that hazardous substances must be prevented from entering groundwater, and the input of non-hazardous substances must be limited to ensure that such inputs do not cause a deterioration in groundwater status, or cause significant and sustained upward trends in the concentration of pollutants in groundwater. Appropriate controls should be placed on activities that discharge substances to groundwater. Therefore, the classification of substances as hazardous or non-hazardous is relevant in all cases where control of an input of pollutants to groundwater is required by the Regulations.

This paper sets out the basis for the Agency’s hazardous substances determinations. Annex I provides a list of substances that have been classified as hazardous or non-hazardous. These substances are considered to present a potential risk of pollution where they are discharged to, or detected in, groundwater bodies.