1. Chemical Status : Open issues on reporting obligation
Open issues on compliance checking
CMA Plenary meeting Ghent 5-6 May 2009
24/02/2019

2. QA/QC directive:
Article 4 Minimum performance criteria for methods of analysis
1. Member States shall ensure that the minimum performance criteria for all methods of analysis applied are based on […] a limit of quantification equal or below a value of 30% of the relevant environmental quality standards.
2. In the absence of relevant environmental quality standard for a given parameter, or in the absence of method of analysis meeting the minimum performance criteria set out in paragraph 1, Member States shall ensure that monitoring is carried out using best available techniques not entailing excessive costs
TITRE DE LA PRESENTATION
24/02/2019

3. Article 5 Calculation of mean values TITRE DE LA PRESENTATION
QA/QC directive:
Article 5 Calculation of mean values
1. Where the amounts of physico-chemical or chemical measurands in a given sample are below the limit of quantification, the measurement results shall be set to half of the value of the limit of quantification concerned for the calculation of mean values.
2. Where a calculated mean value of the measurement results referred to paragraph 1 is below the limits of quantification, the value shall be referred to as 'less than limit of quantification'.
(which LoQ do you take into account when a parameter is a group of substances, when it varies throughout the year ?)
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24/02/2019

4. What to do when LoQ >1/3 EQS or LoQ>EQS ?
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% of unquantified analysis for which LoQ>EQS in France in 2007
for some substances EQS were higher than the EQS of the 2008/105 directive, for some other no standard methodologies available to reach the EQS of the directive 2008/105 : CEN Mandate M424

5. TITRE DE LA PRESENTATION
Reporting : what to do?
(1) : QA/QC directive ?
Mean value < LoQ : 'less than limit of quantification'
if LoQ < 1/3EQS = Good Chemical Status (pale blue)
if LoQ > 1/3EQS = chemical status unknown ? (grey)
Mean value > LoQ => mean value compared to EQS
(2) : Mean value
Unquantified measurand = LoQ/2 (individual) or 0 (group)
Mean value compared to EQS
(3) : Min – Max
Min(mean)> EQS => Bad Chemical Status
Max(mean)<=EQS => good chemical status
Min<=EQS<Max => chemical status unknown
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6. TITRE DE LA PRESENTATION
Bad Chemical status
Good Chemical status ?
Max
(measurand < LoQ = LoQ)
Max
Min
TITRE DE LA PRESENTATION
Min
measurand < LoQ = 0)
EQS_AA
24/02/2019
Max
Min

7. Reporting : 3 options under consideration (parameter level)
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8. Reporting : 3 options under consideration (station level)
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9. Reporting : confidence?
Monitored water body:
Bad chemical status : always high level of confidence
Good chemical status:
What to do if the information is missing for some of the 41 parameters ?
> 80% : high
50-80% : intermediate
<50% : low level of confidence (also when info is missing for PAH or DEHP)
Water body not monitored:
Low level of confidence, unless we know for sure that there is no pollution sources (what about the diffuses sources: PAH)
TITRE DE LA PRESENTATION
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10. Reporting : confidence?
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11. TITRE DE LA PRESENTATION
Thank you for your attention
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12. Définition état chimique - substances
Max
NQE
NQE
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NQE -Min
Min
« Probabilité  bon état » : p = (NQE-Min)/(Max-Min)

13. TITRE DE LA PRESENTATION
Bad chemical status
Good Chemical status ?
Sure
Likely
Likely
Sure
Max
Max
Max
Min
TITRE DE LA PRESENTATION
Max
EQS_AA
Min
24/02/2019
Max
Min
Min
Min