As stipulated in the memorandum Healthy growth, sustainable harvesting (EZ 2013) all plant protection products are monitored, including substances not designated as specific pollutants.
In 2014 standards for long-term exposure were exceeded in just over 60 percent of the measurement locations of plant protection products and biocides (CML 2015). In 2012 this was 50 percent (PBL 2012b). The difference is largely because the standards have been tightened. This applies particularly to the substance imidacloprid, which tightened the standard from 67 to 8.3 nanograms per liter. The number of measurement points with overruns have remained relatively stable over the past decade (60 percent). On most of the measurement locations the norm is exceeded by less than 5 percent of the total number of substances. Remarkably, some standard exceeding substances are not identified as specific pollutants (for example the fungicide azoxystrobin and the insecticide Fipronil).
Standards are exceeded particularly in areas of horticulture, floriculture, flower bulb and open field vegetable cultivation. Standard overruns can have several causes. Some substances are allowed that shouldn’t have been under the criteria of the water quality policy. This is because the admission assessment of plant protection products employs a more lenient criterion for ecological damage than that of the water policy (PBL 2012b). At European level a major step was taken recently to better align the admission assessment with the water quality policy. Other explanations for overrun are negligent use of plant protection products in the Netherlands and inflow from abroad through rivers.
Download the full report (in Dutch) here.