Risks of pesticides to groundwater ecosystems

The current standard for pesticides in groundwater in the Netherlands is the same as that for drinking water: a maximum of 0.1 mu g per liter for each individual pesticide and a maximum of 0.5 mu g per liter for all agents collectively. This standard applies to water located at least ten meters below ground level. It is based on an old detection limit, which is out of date by now, and on the view that drinking water should be entirely free of pesticides. Recently, however, there are increasing calls for a system of standards underpinned by toxicological data. A committee of the Health Council of the Netherlands (please see note at the end of this article) has dealt with the question whether, apart from human health criteria, ecotoxicological criteria should be taken into consideration when evaluating the risks posed by pesticides in groundwater. This paper closely follows the executive summary of her report.