Feature article

Pesticides in groundwater

For the past decade, as part of French and European projects, BRGM has been studying, both in the laboratory and in the field, the transfer of pesticides used in agriculture to a large number of groundwater bodies, in order to gain a better understanding of possible changes in groundwater quality and to facilitate sustainable management.

1 September 2004

Cover of the thematic file.

Improving understanding for better prevention

A European directive issued in 1988 defined maximum concentration thresholds for plant protection products in drinking water (0.1 microgram/litre – µg/L – for each compound analysed or 0.5g/L for all specific compounds combined). Since that date, measurement and control networks have been set up or reinforced and have revealed the contamination of a large number of groundwater bodies by pesticides (herbicides, fungicides, insecticides, etc.), also known as plant protection products.

This "diffuse pollution from agricultural sources" naturally depends on factors such as soil type (some types allow more pesticide transfer than others), the depth of the water table (the deepest layers are little or not yet affected), the intensity of agricultural activities, and the climate.