Structure General remarks Performance of the BLM tool in dependence of input parameters

1. Sensitivity analysis of the EU BLM tool and evaluation with monitoring data sets from German waters Heinz Ruedel, UdoHommenFraunhofer Institute forMolecular Biology and Applied Ecology Christiane HeissGeneral Aspects of Water Quality and Management, Groundwater Protection, German Federal Environment Agency

2. EU BLM tool - sensitivity analysis and evaluation with German monitoring data Structure • General remarks • Performance of the BLM tool in dependence of input parameters • Influence of measurement uncertainty • Characteristics of monitoring data sets • Evaluation of performance with German monitoring data • Results from interviews with experts from monitoring authorities • Conclusions

3. Sensitivity analysis of the EU BLM tool General • The EU BLM tool provided via the Bio-met website was applied (version 1.4, October 2011) • Graham Merrington (wca) kindly provided additional information on the development of the tool • The BLM tool uses pH, DOC and Ca to calculate local QS as dissolved Cu, Ni, and Zn • The BLM tool labels the calculated quality standards as local “EQS”. However, we assume that they are QSfw,eco(QS for freshwater pelagic community) since for the overall EQS also other protection goals have to be considered (e.g., secondary poisoning)

4. Sensitivity analysis of the EU BLM tool Validity range of the BLM tool and applied generic Required documentation • How were the generic QS derived? • How are generic QS related to the PNEC derived in the RAR/VRAR? • Which assessment factors were applied?

5. Performance of the EU BLM tool (version 1.4, October 2011) • Different characteristic for each metal • For zinc at both boundaries and for Ni at the lower pH boundary higher local QS values are implemented as default values

6. Performance of the EU BLM tool (version 1.4, October 2011) • Dissolved organic carbon (DOC) concentration has a strong influence on local QS • Due to the reliance on look-up tables QS change in certain steps

7. Performance of the EU BLM tool (version 1.4, October 2011) • No change of Ni QS on varying Ca concentrations • For Cu and Zn changes of QS outside the boundaries

8. Performance of the EU BLM tool (version 1.4, October 2011) • Influence of the variation of the pH values by + 5 % (measure-ment uncertainty) on the calculated QS (shown as error bar) • Strongest influence observed for Cu

9. Performance of the EU BLM tool (version 1.4, October 2011) • Influence of the variation of the DOC concentration by + 30 % (mea-surementuncertainty) on the calculated QS (shown as error bar) • Strong influence observed for Zn and Cu in the range of DOC steps

10. Performance of the EU BLM tool (version 1.4, October 2011) • Influence of the variation of the Ca concentration by + 10 % (mea-surementuncertainty) on the calculated QS (shown as error bar) • QS is only slightly influenced

11. Test data sets from German monitoring programmes • Data from North Rhine-Westfalia are assumed to be representative • Data from Saxony-Anhalt are especially from salt-rich rivers • Data from Baden-Wuerttemberg are only covering the Neckar river

12. Comparison of German monitoring data with BLM tool validity ranges Example 1 • xx

13. Comparison of German monitoring data with BLM tool validity ranges Example 2 • xx

14. Comparison of German monitoring data with BLM tool validity ranges Example 3 • xx

15. Evaluation of German monitoring data • Exceedance of QS (monthly values, not averaged over one year) • Fraction of dissolved metal concentrations above the local QS calculated with the EU BLM toolfor North Rhine-Westfalia data (several rivers / sites): • 1 % for copper (3262 data) • 12 % for nickel (2664 data) (3.4 % above current EQS of 20 µg/L) • 10 % for zinc(3205 data) • Fraction of dissolved metal concentrations above the local QS calculated with the EU BLM toolfor Baden-Wuerttemberg data (Neckar, 8 sites): • 0.4 % for copper (2593 data) • 0.6 % for nickel (2591 data) (all below current EQS of 20 µg/L) • 1.0 % for zinc (2587 data) For Cu and Zn no comparison to current situation was performed since currently compliance in Germany is assessed on basis of suspended particulate matter (SPM) concentrations and respective SPM quality standards of these metals.

16. Results from interviews with experts from monitoring authorities • Cost benefit analysis • Currently, dissolved metal concentrations are not determined routinely in Germany. Also DOC and Ca measurements are not performed regularly. On-site pH measurement data, on the other hand, are often available • Costs for the additional required measurements were estimated by experts from relevant authorities of federal states to be about 50 - 70 € per sample • It is expected that the advantage of the BLM implementation would be to avoid risk mitigation at sites where the water conditions significantly reduce the bioavailability and thus the potential risk to the aquatic community

17. Conclusions • BLM are an accepted tool to consider bioavailability (EU RAR, SCHER) • User-friendly tool needed to allow implementation in routine monitoring • Transparent documentation is required how generic QS were derived • Step changes of QS are difficult to treat: variations in the range of measurement uncertainty may decide whether local QS are exceeded or not – steady functions seem more appropriate • For about 20 % of the German monitoring data parameters were outside the validity of the EU BLM tool (for the representative data set from North Rhine Westfalia) • Clear instructions are required on how to treat data outside the validated range of the BLM tool • Monitoring experts from German authorities expect clear instructions how to proceed in case of QS exceedances: use of full BLM, consideration of background by added risk approach…. • Currently, dissolved metal concentrations and the additional para-meters Ca, DOC, pH are not measured at all sites in Germany; especially on-site filtration is assessed as critical (contamination)