Ten Years of Pesticide Monitoring in Norwegian Ground Water

Abstract

AbstractPesticides in Norwegian ground water have been monitored since 1995. Here, we report data including 2004. The monitoring has focused on shallow ground water near agricultural fields (4 locations), on farm wells (22 locations), and on public waterworks (38 locations) 450 samples were analyzed for a total of 62 pesticide compounds and metabolites, and the result was 514 detections of single compounds. Altogether 27 pesticides and metabolites were detected: 2 insecticides, 9 fungicides, and 16 herbicides. Herbicides were most frequently detected (in 79% of the samples), followed by fungicides (20%) and insecticides (1%). Pesticide concentration was generally low, although high concentrations also occurred, for example, 33 μg/L of metribuzine in shallow ground water near agricultural fields and 20 μg/L of bentazon in a farm well. Some water soluble pesticides occurred both frequently and with relatively high concentrations in shallow ground water near agricultural fields. The results show that local ground water near farms is vulnerable for contamination of pesticides and needs further monitoring. Efforts should be made to minimize contamination of wells in farming areas through education on pesticide use, monitoring, and well positioning. Few pesticides were detected in ground water from waterworks and the concentrations were low. Monitoring of waterworks ended in 2002. The data show that there is a continuous need to monitor pesticides as well as selected metabolites in shallow ground water and wells near agricultural fields in Norway.