THE POLLUTION OF WATER BY PESTICIDES - ST ATE AND ORIGIN

In Europe, monitoring campaigns of surface and groundwaters used for d rinking water frequently show pollution by pesticides, above the EU sp ecification. This situation is due to intensive agriculture, non-respe ct of good agricultural practices, non-agricultural uses and the exist ence of especially vulnerable sites (eg, thick and diffuse hydrologica l system, broken relief, filtering or cracked soils, water table lying near the surface). The assessment of the pollution can be conducted a t different levels. However, local study appears to be the only satisf actory method. Indeed, it allowed us to focus on some pesticides, samp ling dates and water supplies, in relation to the local characteristic s. In France, few pesticides are involved in water pollution: atrazine , simazine, lindane, carbofuran and phenylureas. However, this list wo uld be different if practices carried out locally or degradation produ cts (deethylatrazine) were taken into account. The pollution of surfac e water can reach a high level but for a small time. It is closely rel ated to the ability of pesticides to be transported by runoff, and the dilution with water from untreated areas. In contrast, groundwater is weakly but, in some instances, continuously polluted. This depends on the leaching processes, and, hence, on the availability of pesticides and the wafer dynamics. In the case of pesticides with high persistan ce and relatively good mobility, the storage of pesticides in soil sus tains the groundwater pollution.