Table of contents
3. Further comments
1) Here is space for additional comments reviewers may wish to make.
Should you have comments on:
- the approach to normalising the data;
- non-relevant metabolites for groundwater;
- the use of RACs for threshold exceedances in surface waters;
- further sources for EQS values;
please use the sections below.
2) Approach to normalisation - use of country area weighting
Fig 1 uses country area weighting as a way to normalise the reported data. Country area weighting has some disadvantages (principally that if a country with a large area has a high exceedance rate in one year, that can influence the overall result) but this approach seems to be a reasonable way to normalise the results and be less prone to fluctuations owing to variability in numbers of reported data. We expect some noise in the data as the WISE 6 reporting adapts to this new indicator, but that this will settle down in a few years to provide a more consistent trend.
3) Exclusion of non-relevant metabolites from groundwater indicator assessment
We excluded non-relevant metabolites (nrM) from the calculation of exceedance rates in groundwater. This is in line with the 2006 Groundwater Directive, where the quality standard for pesticides of 0.1µg/l does not apply to nrM.
However, recent work towards a Europe-wide study recommends inclusion of nrM in Annex I of the Groundwater Directive, with the need to establish harmonised definition and assessment of nrM and to set quality standards in line with quality standards of Groundwater Directive.
Should nrM be included in the indicator? If so, what quality standards should apply?
4) Possible use of Regulatory Acceptable Concentrations (RAC) as effects threshold for pesticides in surface waters
Exceedances in surface waters were calculated using EU-wide or nationally-regulated thresholds (Environmental Quality Standards – EQS). We could not find EQS for about a third of the pesticides reported to WISE-6, which means these substances could not be included in the assessment of threshold exceedance.
Under Regulation 1107/2009 (PPP Regulation), RACs are required for pesticides to prevent harm to aquatic organisms. We investigated the possibility of using RACs as an alternative threshold to EQS, as all pesticides should have RAC values. However, we found that RACs and EQS could not be used interchangeably, as they consider different protection goals, apply to different spatial scales and are based on different valuation methods.