English Abstract The Dutch groundwater quality monitoring network
includes 380 monitoring points. The frequency of sampling is once a year.
The objectives of the network are: - to make an inventory of the present
quality in relation to soil use, type of soil and hydrogeological conditions
; - to distinguish long term changes in quality ; - to provide data for
quality control and groundwater control ; - to indicate the extent of human
influence on groundwater quality. This report gives the results of analysis
in 1989 from 21 monitoring points in the province of