1. EU Water Framework Directive
One-out all-out principle
Workshop on monitoring and classification systems
Paris, June 2007
Jorge Rodriguez Romero
European Commission, DG Environment
Unit D.2 – Water and Marine, WFD Team

2. Why do we need the one-out all-out principle
WFD addresses all pressures and impacts
Biological quality elements respond differently to the various pressures
If one biological quality element is failing due to an impact this should be addressed
Annex V section 1.4.2: “For surface water categories, the ecological status classification for the body of water shall be represented by the lower of the values for the biological and physico-chemical monitoring results for the relevant quality elements classified in accordance with the first column of the table set out below [high-good-moderate-poor-bad].”

3.     Classification Intercalibration Combination Classification
Macroinvertebrates
Combination
rules
Classification 
Map
high
good
moderate
poor
bad
Phytobenthos
Intercalibration 
Macrophytes 
Fish
Combination rules should:
Ensure comparability (need to have common principles)
Be transparent (what does each colour mean)
Physico-chemical
Hydromorphology

4. Principles of combination rules in the Classification Guidance

5. Confidence and precision of results
Any assessment method produces false positives and false negatives
The reliability of the resulting classification will depend on the reliability of the individual results used in the combination rule
WFD requires to estimate confidence and precision of monitoring
A minimum confidence and precision is needed to use the results for classification (for any combination rules!)
There is plenty of guidance on how to improve confidence and precision in the ECOSTAT Classification Guidance

6. Improving confidence in unclear cases
Increase monitoring frequency
Use additional parameters
Improve robustness of the methods (selection of sampling sites, sampling method, taxonomic level, …)
Take account of local spatial and temporal conditions
Take account of pressure/impact analysis and carry out detailed ad-hoc surveys if necessary (e.g. field surveys)
Use investigative monitoring where appropriate

7. Conclusions (I)
The one-out all-out principle is a key element in the WFD as it ensures that all pressures and impacts are addressed
This should be recalled when developing combination rules
Be transparent:
translate one-out all-out in a set of operational rules that respect the principles and suit your assessment methods
Develop clear minimum confidence and precision criteria for results to be taken into account
Explain how you reduce and manage the risks of false positives or false negatives
Explain under which circumstances you may disregard certain results (certain quality elements in certain types, certain natural circumstances, etc)

8. Conclusions (II) Communication of results
There is a need to find a way to present the classification results in a comparable way
Be efficient and flexible in monitoring programmes (adaptive management!)
focus monitoring efforts on non-clear cut cases, reduce spending in clear “high or good” or “less than good” situations
use ad hoc pressure/impact analysis and/or investigative monitoring to increase confidence and certainty in unclear cases