1. Biotic Ligand Models (BLMs) for metals – Current validation boundaries and ongoing initiatives

2. Outline
Introduction
Extending the validated boundaries of the BLMs – Progress?
Nickel
Copper
Zinc
Future BLM/User-friendly tool boundaries
Regulatory fit?
What else is needed?

3. Nickel
Toxicity measured at pH values up to 8.7 (Lymnaea stagnalis, Brachyionus calcyciflorus, Daphnia magna, Pseudokirchneriella subcapitata, Lemna minor).
New pH relationships now incorporated into model
Algae and cladoceran models validated at Ca concentrations down to 2 mg Ca L-1.
Work completed

4. Copper
From study reviews, raised Ca to 160 mg L-1 can be used as upper Ca-boundary.
Assessment is on-going of the Ca/Mg effect for invertebrates. Additional research will be initiated, if needed, following the finalisation of the literature review.

5. Zinc
Extension of the boundaries of the current BLM from pH 8.0 to 8.5, and of hardness down to 3 mg Ca l-1.
Tests at very low hardness have already been carried out.
Algae testing to be performed between 3 and 5 mg Ca l-1 and validated with natural waters.

6. Extended BLM boundaries
Metal pH
Calcium, mg L-1
DOC, mg L-1 Cu
6-8.5 30 Ni
2.0-88* Zn *
*These upper limits reflect only where the protective effect of Ca ceases,
so above this value the EQS is not going to be underprotective.

7. Version 2.0 update. Extended Ni validated boundaries
Ambient Background Concentration (ABC) calculations for Zn

8. Online version of 2.0 (in beta testing) www.bio-met.net
Version 2.0 update.
Extended Ni validated boundaries
Ambient Background Concentration (ABC) calculations for Zn
Subsequent updates:
Extended Cu boundaries by December 2013
Extended Zn boundaries, 1st phase validation with natural waters (low hardness, high pH) July 2013
Online version of 2.0 (in beta testing)

9. Regulatory fit?
Compliance assessments need to be performed using the right EQS!
Risk assessments are of limited help if the EQSbioavailable isn’t used appropriately
Tiered approach
Bioavailability can assist in site prioritisation and programmes of measures
Challenges of permitting discharges using an EQSbioavailable - current on-going UK project.

10. What else is needed? Guidance note on the bioavailability approach
Appropriate action when outside the validation ranges?
Demonstrations from Member States who are working with the approach (France, The Netherlands, UK....)?
Feasibility assessments, like the Fraunhofer Report