Katrien Delbeke, ECI, Frank Van Assche ,IZA- Europe On behalf of the Eurometaux Water Project Team

1. Accounting for bioavailability and natural background under the WFD Perspective of the Metals Industry Katrien Delbeke, ECI, Frank Van Assche ,IZA- Europe On behalf of the Eurometaux Water Project Team

2. Content WFD issues for metals Metal bioavailability Metal background levels Conclusions

3. Water quality standards setting for metals:issues For the EQS setting on metals, a number of specific characteristics have been recognized: • Some Metals are data-rich and the ecotoxicity data quality is variable • All are Natural Elements, occurring with varying background levels in water • Bioavailability is key to understand the possible ecological impact of metals

4. From RA to WFD: ecotoxicity data • For several metals, EU risk assessments have been made • Approved data sets are available • RA data sets checked for quality and relevancy • But the EU RA = generic assessment on EU-wide scale  EU RA = considers uncertainties at an EU wide scale • WFD = National (river basin) assessments • WFD = more refined approach, more specific to local water conditions • WFD = generic + site - specific information (BG & bioavailability)  uncertainties reduced for EQS setting

5. Integrating Metal bioavailability In EQS setting

6. Use of bioavailability in EU regulations • Corrections for metal Bioavailabilityhave been applied in EU Risk Assessments - Cd : Hardness correction on dissolved metal concentrations - Zn, Ni, Cu : BLM correction on dissolved metal concentrations • Bioavailability phrasing of the WFD (2000/60/EC): - “ In the case of metals the EQS refers to the dissolved concentration” - “…if pH, Hardness and other water quality parameters affect the bioavailability of metals, member states may take this into account when assessing the monitoring results against the EQS”

7. Tiered approach to account for bioavailability Tiered approach (UK, WFD proposal) • Tier 1 : EQS = reference PNEC • Check PEC against ref PNEC • If exceedence: go to tier 2 • Tier 2 : account for metal bioavailability •  Check PEC against site specific PNEC

8. Importance of bioavailability for metal toxicity Toxicity of metals to Daphnia magna in different EU surface waters Cu Up to factor 30 difference in EC50 D.magna explained by bioavailability Evidence on site-specific toxicity for - Cd • Zn • Ni • Cu • …. Zn

9. The BIOTIC LIGAND MODEL- BLM Principles of metal toxicity: Key target for metal toxicity = gills or gill-like structures

10. BLM toxicity prediction from water characteristics –zinc example Daphnids Toxicity predicted within factor 2 Algae Toxicity predicted within factor 2 Original unexplained variability : factor 10-50 After BLM correction : unexplained variability : factor 2-3

11. Criteria for use of bioavailability in RA & EQS For at least 3 dissimilar groups, for a range of test media,demonstrate,that NOECs variability < factor 5

12. Scientific evidence : BLM developments & validations - some other species Unexplained variability : from factor 70 to factor 2-3

13. Incorporation of Bioavailabilityin EQS setting Individual NOECs (varying pH, H, DOC,…) Bioavailability translator (BLM) «  fish, invertebrates, algae » Normalised NOECs ( related to site-specific water) SSD  Site-specifc EQS Refined Risk ratio = PEC/EQSsite

14. Full BLM normalization – case example: Cu in the river Rhine Normalisation of NOECs with c-BLM Water chemistry - Rhine pH : 7.8 DOC : 2.8 mg/L Ca : 65mg/L Mg : 11 mg/L Na: 37 mg/L K : 56 mg/L Alkalinity : 119 mg CaCO3/L Normalised SSD Risk in Rhine if PECdissolved > 8 µg Cu/L

15. Specific EQSs for different EU waters example: Cu

16. Water parameters driving Bioavailabilityand available bioavailability tools • Key parameters driving bioavailability for Cu, Zn, and Ni are DOC and pH • Other drivers can be Ca, Mg, alkalinity, Na,… • Dependent of the metal • Available tools: • Cd: Hardness algorithm • Cu, Zn, Ni: user-friendly software for BLM calculations

17. Remaining issues for discussion under WFD Measurements of bioavailability parameters 1) Temporal variability? make average? 2) Include in all monitoring, or only in cases of exceedences of the ref PNEC? • = Tiered approach?

18. Variability in bioavailability parameters Seasonal versus geographic variability in BLM variables : DOC From : Kramer et al., 2004

19. Background levels Metals are Natural Elements, occurring in varying background levels Background corrections under the WFD (2000/60EC): - “If natural background values are higher than the EQS member states may take this into account when assessing the monitoring results against the EQS” ISSUES : - How to account for natural background levels - How to set a natural background level

20. How to account for natural background levels • Zn RA and AMPS (2004): added risk approach (ARA) • EQS = BRC+ MPA - BRC = background reference concentration - MPA = maximum permissible addition (= PNEC - background test media) • In Cd, Pb, Ni & Cu RA, effects are based on total metal levels. • EQS = PNEC (site-specific).

21. How to account for natural background levels • Tiered approach (UK, WFD proposal) -Tier 1 : total risk approach (site specific) • EQS = PNEC (site-specific) • If exceedence: tier 2 -Tier 2 : account for background level • EQS = BRC + MPA - BRC = background reference concentration - MPA=maximum permissible addition (= PNEC - background of test media)

22. How to set natural background levels • CMA - AMPS (June 2004) provided some possible methods for BRC values to be chosen in a particular river basin: • Analysed values for trace Metal Concentrations in Pristine Areas (with assurance that river basin is pristine or nearly so) • Trace Metal Concentrations in Groundwater (shallow and/or deep) • Expert Judgement (incl. International agreements; River basin commissions).

23. How to set natural background levels • CMA - AMPS (June 2004) evaluated the FOREGS ambient geochemical baseline data for Europe(http://www.gsf.fi/foregs/geochem/) as possible EU wide reference BRC values •  The FOREGS database has good merits: - high quality database - consistency in sampling and analysis - Sampling in unaffected areas BUT , the scale of sampling is rather coarse and THUS, local data are still preferred

24. Example of Foregs maps

25. Initial Tiered approach for compliance checking Tier 1 : Reference EQS No risk National pH,DOC…: Within Reference EQS boundaries? Compliance? C diss<EQS ref yes yes no no Tier 2 : Bioavailability correction Local EQS Within BLM Boundaries? No Risk no yes Compliance? C diss<EQS local yes Case by case evaluation no Tier 3 : Background correction yes No risk Compliance? C diss -Cb <EQS local add Local Background Added EQS yes no Risk

26. Conclusions

27. Key Conclusions • EQS setting needs high quality ecotoxicity data. RA PNECs should be used as a basis, if available. • Criteria have been set on the acceptance of bioavailability models (eg BLMs) for use in RA’s and EQS settings. • The implementation of background corrections in an added risk approach has been proposed. The derivation of appropriate river –basin specific background values needs to be established. • For several metals (Zn, Cu, Ni (almost finalized)),user-friendly bioavailability models have been developed by industry and tested by UK & NL. They are available to water authorities.

28. Key Conclusions • The implementation of bioavailability corrections means that bioavailability parameters (pH, DOC, Ca, Mg, Na, alkalinity) are to be measured. • Remaining discussions will take place at the EQS- Metal WG • Guidance document on metal EQS • Bioavailability • Background • Criteria for need of Sediment and Biota EQS

29. Industry recommendation • Co-operation between industry and EU-MS, in the framework of RAs and bilateral discussions, will be useful for further methodological development.