1. Analysis and Monitoring of Priority Substances and Chemical Pollutants
AMPS 3
3rd meeting of the expert group on
Analysis and Monitoring of Priority Substances and Chemical Pollutants
Additional meeting for support to EQS group on:
Data Quality requirements
Monitoring matrices
Metal background concentrations
Drafting group sessions on 8./9.4.03, AMPS 3 on 10./

2. AMPS 3 Documents
Prepared by drafting groups, discussed by AMPS, commented:
Data Quality requirements
EAF(5) AMPS-DQR
Monitoring matrices
EAF(5) AMPS-Matrices
Estimating natural background concentrations
EAF(5) AMPS-Background

3. Data quality requirements
EQS
(i) Result + uncertainty above EQS
(ii-a) Result above EQS but EQS within uncertainty
(ii-b) Result below EQS but EQS within uncertainty
(iii) Result + uncertainty below EQS
Reported average value
Uncertainty

4. Uncertainty of reported average
Uncertainty total
Uncertainty sampling
Uncertainty measurement
Specific pattern of PS occurrence in specific waterbody (uncontrolled)  adapt suitable sampling strategy (spatial & temporal)
* total =  sampling +  measurement
*  = variance
Error from analytical measurement method  analytical quality can be described and controlled

5. Position paper on data quality requirements
The objective is to define data quality requirements for analytical measurements. This information should be taken into account when compliance assessment is considered.

6. Basic assumptions
The proposed EQS for the water phase were taken as reference for discussion
EQS include precautionary factors (10 to 1000)
EQS refer to the annual average concentration
All discussions on DQR refer to analysis of PS in water
The group recognises that quality of measurement will be an important factor for the decision of compliance. However, the decision of compliance of reported data (annual average) is not within the competence (task) of AMPS

7. Basic questions
Which data quality elements should be taken into account?
What data quality is currently achievable by available methods?
What data quality is required?

8. Which data quality elements should be taken into account?
Uncertainty of measurement
Def.: Parameter associated with the result of a measurement, that characterises the dispersion of the values that could reasonably be attributed to the measurand. Eurachem guide (2000)
Lower limit of application
The lower limit of application refers to the lowest concentration for which a method has been validated with specified accuracy. Adopted according to definition of “range of application” ISO/TR 13530

9. What data quality is currently achievable by available methods?
Information on measurement uncertainty from 10 European countries received through questionnaire
First idea on what measurement uncertainty is achievable in routine laboratories in order to propose realistic requirements
Uncertainty information for concentrations far above proposed EQS has been excluded

10. What data quality is currently achievable by available methods?
For some of the PS there is currently not enough data for measurement uncertainty available (chloroalkanes, PBDE, tributyltin compounds).
For some PS the EQS is much lower than current lower application limits (e.g., tributyltin compounds).
For some PS (such as PBDE) data are only available for other matrices than water.
Measurement uncertainty (expressed as RSD) for PS has been mostly estimated to be in the range between 10 and 30%.
Only for a few PS uncertainty estimates are between 30 and 40% or lower than 10%

11. What data quality is currently achievable by available methods?
From the available data it can be derived that most of the PS can be measured with an uncertainty below 30%. In order to stimulate data quality improvement, a realistic achievable combined standard uncertainty of 25% is proposed
Information on the contribution of sampling to uncertainty is not included in the table, although the group considers it as very relevant. Only two out of ten European countries gave some information on uncertainty related to sampling

12. What data quality is currently achievable by available methods?
Laboratories have to be aware that sampling can contribute to overall uncertainty of measurement, but its contribution is difficult to quantify. Based on expert judgement the contribution of taking and transporting samples is considered to be small compared to uncertainty of measurement. To minimise uncertainty associated with sampling, samples should be taken according to international guidelines on sampling in water analysis.
The contribution of statistical sampling uncertainty (representativeness, i.e. “when and where” samples are taken) can be very significant and may be even greater than the analytical measurement uncertainty

13. What data quality is required?
A table has been drafted to propose required measurement uncertainty (Annex B)
Based on the assessment of uncertainty information from 10 European countries a combined standard uncertainty (RSD) of 25% has been proposed as default
A coverage factor (for definition see Annex A) of 2 (corresponding to an approximate level of confidence of 95%) is chosen to derive the expanded uncertainty of 50%

14. What data quality is required?
The lower limit of application is required to be equal or lower than 30% of the EQS. This ensures that PS concentrations around the proposed EQS can be measured with acceptable uncertainty
The proposals for required uncertainty and lower limit of application cannot be achieved for several PS at present
Laboratories should work according to internationally accepted QA/QC schemes (e.g. as required in the accreditation standard EN/ISO/IEC 17025).

15. Monitoring Matrices for compliance checking of Priority Substances in the WFD
AMPS has been asked for a recommendation on the suitable monitoring matrix for PS from the viewpoint of the analytical experts in order to support EQS setting.
The objective is to give a recommendation on the preferred matrix for surveillance and operational monitoring of PS.

16. Discussion items :
Definition of matrices in aquatic systems. Common understanding of “water” phase, whole water or only dissolved fraction.
Partitioning of substances between different phases (Kow/Koc/Kd). The physico-chemical properties of compounds, the water quality and the solid phase composition and concentration (suspended particulate matter/settled sediment) determine the partitioning.

17. Discussion items :
Preference between SPM/ settled sediment depending on monitoring strategy and aim. Keywords are: historic pollution, protection of the benthic organisms, resuspension, sampling of top sediment layer, time/investment needs for SPM sampling, etc.
Concentrations and organic matter content of SPM in the water column
Dissolved Organic Carbon DOC concentration in water
Feasibility of analytical methods in a specific matrix
Need for harmonised protocols for the separation of phases and for the analyses of contaminants in “whole water” in presence of large SPM concentration

18. Conclusions
For a number of compounds the analysis in the water phase is recommended
It is not recommended to analyse PBDE in the water phase
For some compounds the analysis in the water phase is currently not possible at the proposed EQS levels. Analysis in a different matrix might provide a practical alternative in these cases.
For the other compounds no general clear statement can be made at present and further discussion is needed

19. Conclusions
It is desirable to use only one analytical method (matrix) for substance groups (such as PAH)
Groups of related substances, such as volatile compounds or some pesticides should be analysed in the same matrix
SPM is a suitable matrix for monitoring some hydrophobic substances and metals but requires dedicated instruments and harmonised methods. SPM monitoring is not recommended if the SPM concentration is low.

20. Recommended Monitoring Matrix Water for:
Alachlor
Atrazine
Benzene
Chlorfenvinphos
Chlorpyrifos (-ethyl, -methyl)
1,2-Dichloroethane
Dichloromethane
Diuron
Endosulfan
Hexachlorobenzene
Hexachlorobutadiene
Hexachlorocyclohexane
gamma-HCH (Lindane)
Isoproturon
Pentachlorobenzene
Pentachlorophenol
Simazine
Trichlorobenzenes
Trichloromethane 

21. Recommended Monitoring Matrix is other than water for:
Bis(pentabromophenyl)ether
Diphenyl ether, octabromo derivate
Diphenyl ether, pentabromo derivate

22. Metal background concentrations
Monitoring of priority metals (Cd, Hg, Ni, Pb) in the context of the WFD
“Added risk approach”
Compilation of methodologies for estimating natural background concentrations

23. Definition
“The background concentration of target metals(Pb, Cd, Ni, Hg) in the aquatic ecosystems of a river basin, river sub-basin or river basin management area is that concentration in the present or past corresponding to very low anthropogenic pressure.”
This definition is based in its intent on the REFCON Guidance document accepted by the Water Directors in November 2002.

24. Spatial variability
For the purpose of quality standard setting, background concentrations might be estimated under consideration of spatial (and if necessary seasonal) variability. Furthermore, the river basin or river basin management area is defined as the spatial entity that is considered as uniform with regard to the background concentration of a particular metal.

25. Methodologies for estimating natural background concentrations
Dissolved Phase
1. Trace Metal Concentrations in Groundwater
Shallow
Deep
2. Trace Metal Concentrations in Pristine Areas
3. Watershed Model
4. Expert Judgment

26. Methodologies for estimating natural background concentrations
Particulate Phase
Trace Metal Concentrations in Pristine Areas
Calculation using Kd, TSM and [Diss-TM] Kd * [TM-D ] *TSM = [Part-TM].
Calculation from composition of surface sediments (OM, Inorg Phases; TMs in Phases; Apportioned to TSM
Expert Judgment