The major impact is made on the local communities which mostly rely on groundwater supplies. It is important to note the substances, which are mostly found in the waters across Europe:
'Pesticides have also been found in European rainwater. Approximately half of the compounds analysed were detected. For those detected, most concentrations were below 100 ng/l, but larger concentrations, up to a few thousand nanogrammes per litre, were detected at most monitoring sites. The most frequently detected compounds were lindane (gamma-HCH) and its related isomer (alpha-HCH), which were detected on 90-100% of sampling occasions at most of the sites where they were monitored.' (Pretty & Brett, 2000)
Despite the fact that the issue of water contamination with pesticides is constantly being addressed, and certain improvements take place, the problem is still serious; while much has been said about the environmental impact of the pesticide pollution of waters around Europe, not everyone yet realizes what economic impact pollution carries with itself. Water quality in the UK has already improved, and the level of this improvement is estimated at the level of 25%. (Pretty & Brett, 2000) Further improvements will take place as soon as the existing policies are completed. It is essential to state, that the differences which exist in water quality within the UK are significant, and while Wales is known for possessing 90% of its river length of good water quality, England's rivers contain only 60% of the waters which may be called good from the viewpoint of their ecology.
Economic disadvantages of water pollution lie in the external costs which are necessary to carry out the analysis, monitoring, development and realization of the policies for the improvement of the water quality and elimination of pesticides' residues (or at least putting them to the reasonable legal limits). There is some data which exists in relation to the external costs of pesticide water pollution for certain European countries. It will be appropriate here to quote the data found in Waibel (2001) about the costs which the Dutch water industry has experienced through the period of 1990-2000; the total costs were equal to 240 million euro.
Cost for analysis
Monitoring of resources (inventorial studies)
Protection of water resources
Replacing or abandoning of well fields and/or water treatment processes
Research on water treatment processes and pesticide removal
Purification/water treatment (also temporary measures)
Meetings, training and public relations (costs for personnel)
Table 1. Costs of pesticide contamination to Dutch water industry in 1990-2000 (Waibel, 2001)
Looking through the figures above and analyzing them, one comes to the conclusion that contaminating water with pesticides is economically deficient. Economic deficiency is explained by understanding that poor water quality deprives national and European economy of the certain number of benefits; first of all, better quality of water means better environment, and