Final Technical Report on activity: 5:Intercalibration of the regional water quality laboratories, in conformity with WFD implementation adequate Equipment acquisition, materials and consumables

(Final Technical Report on activity: 5:Intercalibration of the regional water quality laboratories, in conformity with WFD implementation adequate Equipment acquisition, materials and consumables ) (Authors: Chem. Carmen HamcheviciDr. biol. Gabriel Chiriac) (Project Partner 2: National Administration Romanian WatersProject Coordinator from PP2Mat. Olga VASILESCUWater Management Resources Dept. ManagerDr. eng. Drago CAZAN)

Table of content1.Sub-activity 5.1.: Acquisition of necessary reagents and equipment sets92.Sub-activity 5.2.: Water Quality analysis for laboratory intercalibration142.1.Objectives of laboratories intercalibration152.2.Main types of laboratories intercalibration162.2.1.Proficiency Testing (PT) schemes162.2.1.1.General aspects162.2.1.2.Types of Proficiency Testing schemes172.2.1.3.Use of PT schemes by the laboratory182.2.1.4.Assessment of results of the PT schemes18Basic elements191.Assigned value192.Standard deviation for proficiency assessment20Performance evaluation202.2.2.Specific Laboratory intercomparisons222.2.2.1.Comparisons under Investigative Monitoring JDS type222.2.2.2.Intercomparisons under Regular Transboundary Exercises232.2.2.3.Performance assessment in Qualco Danube252.2.2.4.Examples of Qualco-Danube results for two danubian laboratories in Romania282.2.3.Intercomparisons by bilateral agreements332.2.3.1.Objective332.2.3.2.Protocol for bilateral action332.2.3.3.Common Romanian Bulgarian Inter-comparison activity June 2015353.General aspects on the cooperation in the Danube River basin383.1.History of TNMN393.2.Description of TNMN403.2.1.Objectives of TNMN403.2.2.Revision of the TNMN to meet the objectives of EU Water Framework Directive (2000/60/EC) (Yearbook, 2011)413.2.3.Network of monitoring locations424.Materials and methods434.1.Monitoring stations434.2.Data collection and processing444.3.Sampling and analysis465.Statistical approach486.Results and discussion506.1.Primary monitoring datasets506.2.Data comparability based on univariate statistics long term data536.2.1.Comparison of monitoring data based on the entire data sets536.2.1.1.Pristol / Novo Selo transboundary section536.2.1.2.Chiciu / Silistra transboundary section626.2.2.Comparison of monitoring data based on the simultaneous data sets696.2.2.1.Pristol / Novo Selo transboundary section696.2.2.2.Chiciu / Silistra transboundary section796.3.Data comparability on short term876.3.1.Data comparability in Pristol / Novo Selo section (January September 2014)886.3.2.Data comparability in Chiciu / Silistra section (January September 2014)957.Conclusions1018.References103

List of Tables

Table 1: Equipment and reagents foreseen to be purchased within the sub-activity 5.1 of Activity 512

Table 2: Analytical performances required for selected determinand list for water quality within TNMN24

Table 3: Water Quality parameters proposed to be analyzed during the common intercomparison exercise June 2015. Investigated matrix: water33

Table 4: List of TNMN monitoring sites located on the common BG RO Danubian stretch within the TNMN network43

Table 5: Analytical standards methods used within TNMN Programme for selected water quality parameters45

Table 6: Descriptive statistics for selected water quality parameters measured at Pristol / Novo Selo transboundary section by the two involved partners (BG-RO) during 1996 - 200554

Table 7: t-test for independent variables (BG-RO) for six water quality parameters measured in Pristol / Novo Selo transboundary section (monthly concentrations during 1996 2005)55

Table 8: Descriptive statistics for selected water quality parameters measured at Chiciu / Silsitra transboundary section by the two involved partners (BG-RO) during 1996 - 200563

Table 9: t-test for independent variables (BG-RO) for six water quality parameters measured in Chiciu / Silsitra transboundary section (monthly concentrations during 1996 2005)64

Table 10: Simultaneous sampling dates (BG and RO) for Pristol / Novo Selo sampling section during 1996 - 200570

Table 11: t-test for independent variables (BG-RO) for six water quality parameters measured in Pristol / Novo Selo transboundary section (simultaneous sampling days during 1996 2005)71

Table 12: Descriptive statistics for selected water quality parameters measured at Pristol / Novo Selo transboundary section by the two involved partners (BG-RO) in simultaneous sampling days during 1996 - 200572

Table 13: Simultaneous sampling dates (BG and RO) for Chiciu / Silistra sampling section during 1996 - 200579

Table 14: t-test for independent variables (BG-RO) for six water quality parameters measured in Chiciu / Silistra transboundary section (simultaneous sampling days during 1996 2005)80

Table 15: Descriptive statistics for selected water quality parameters measured at Chiciu / Silistra transboundary section by the two involved partners (BG-RO) in simultaneous sampling days during 1996 - 200581

Table 16: t-test for independent variables (RO-BG) for eleven water quality parameters measured in Pristol / Novo Selo transboundary section (January September 2014)88

List of Figures

Figure 1 (left): Chemical oxygen consume unit (budgetary line V.22.8) for determination of Chemical Oxygen Demand (COD) by potassium dichromate9

Figure 2 (above): Ultrasonic bath (budgetary line V.18.13) for sampling preparation9

Figure 3: TOC/TN analyzer (budgetary line V.22.11) used for analysis of the following water parameters: Total Organic Carbon (TOC), Dissolved Organic Carbon (DOC), Total Nitrogen (TN)10

Figure 4: Atomic Absorbtion Spectrophotometer (budgetary line V.18.7) used for analysis of heavy metals10

Figure 5: UV-VIS Spectrophotometer (budgetary line V.18.6) used for analysis of nutrients forms (N-NH4, N-NO2, N-NO3, P-PO4, Total P)11

Figure 6: Gas Chromatograph with FID Detector (budgetary line V.18.8) used for analysis of Hydrocarbon Oil Index11

Figure 7: Sample preparation and evaluation scheme for AQC in the Danube River basin (Five years Report on Water Quality in Danube River Basin Based on Trans-National Montoring Network, 2003)26

Figure 8: Evaluation of the analytical quality performance for Laboratory 1 within the Qualco-Danube AQC Scheme during 1998 2004 (N-NH4)29

Figure 9: Evaluation of the analytical quality performance for Laboratory 2 within the Qualco-Danube AQC Scheme during 1998 2004 (N-NH4)29

Figure 10: Evaluation of the analytical quality performance for Laboratory 1 within the Qualco-Danube AQC Scheme during 1998 2004 (N-NO3)30

Figure 11: Evaluation of the analytical quality performance for Laboratory 2 within the Qualco-Danube AQC Scheme during 1998 2004 (N-NO3)31

Figure 12: Evaluation of the analytical quality performance for Laboratory 1 within the Qualco-Danube AQC Scheme during 1998 2004 (P-PO4)31

Figure 13: Evaluation of the analytical quality performance for Laboratory 2 within the Qualco-Danube AQC Scheme during 1998 2004 (P-PO4)31

Figure 14: Evaluation of the analytical quality performance for Laboratory 1 within the Qualco-Danube AQC Scheme during 1998 2004 (P-PO4)32

Figure 15: Evaluation of the analytical quality performance for Laboratory 2 within the Qualco-Danube AQC Scheme during 1998 2004 (P-PO4)32

Figure 16: Common Romanian Bulgarian sampling exercise in Chiciu (RO) / Silistra (BG) (km 375) transboundary section on the 8th of June 2015. Left: sampling recipients dedicated to heavy metals analyses according to the SOP. Right: Romanian team from the Dobrogea Water Branch meeting the Bulgarian team36

Figure 17: Common Romanian Bulgarian sampling exercise in Pristol (RO) / Novo-Selo (BG) (km 834) transboundary section on the 16th of June 2015. Romanian team from the Jiu Water Branch meeting the Bulgarian team37

Figure 18: The Danube Station map TNMN47

Figure 19: Model of a box-plot representation49

Figure 20: Number of annually results produced by BG and RO at Pristol / Novo Selo transboundary section for N-ammonium and N-nitrates during 1996 - 200550

Figure 21: Number of annually results produced by BG and RO at Pristol / Novo Selo transboundary section for P-orthophosphates and Total Phosphorous during 1996 - 200551

Figure 22: Number of annually results produced by BG and RO at Pristol / Novo Selo transboundary section for Biochemical and Chemical Oxygen Demand during 1996 200551

Figure 23: Number of annually results produced by BG and RO at Chiciu / Silistra transboundary section for N-ammonium and N-nitrates during 1996 200552

Figure 24: Number of annually results produced by RO at Chiciu / Silistra transboundary section for P-orthophosphates and Total Phosphorous during 1996 200552

Figure 25: Number of annually results produced by BG and RO at Chiciu / Silistra transboundary section for Biochemical and Chemical Oxygen Demand during 1998 200553

Figure 26: Box-plot of N-NH4 monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section during 1996 - 200556

Figure 27: Box-plot of N-NO3 monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section during 1996 200557

Figure 28: Box-plot of BOD5 monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section during 1996 200558

Figure 29: Box-plot of COD-Cr monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section during 1996 200559

Figure 30: Box-plot of P-PO4 monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section during 1996 200560

Figure 31: Box-plot of TP monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section during 1996 200561

Figure 32: Box-plot of N-NH4 monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section during 1996 200564

Figure 33: Box-plot of N-NO3 monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section during 1996 200565

Figure 34: Box-plot of BOD5 monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section during 1996 200566

Figure 35: Box-plot of COD-Cr monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section during 1996 200567

Figure 36: Box-plot of P-PO4 monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section during 1996 200568

Figure 37: Box-plot of TP monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section during 1996 200569

Figure 38: Box-plot of N-NH4 monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section in simultaneous sampling days during 1996 200573

Figure 39: Box-plot of N-NO3 monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section in simultaneous sampling days during 1996 200574

Figure 40: Box-plot of BOD5 monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section in simultaneous sampling days during 1996 200575

Figure 41: Box-plot of COD-Cr monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section in simultaneous sampling days during 1996 200576

Figure 42: Box-plot of P-PO4 monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section in simultaneous sampling days during 1996 200577

Figure 43: Box-plot of TP monthly concentrations measured by BG and RO in Pristol / Novo Selo transboundary section in simultaneous sampling days during 1996 200578

Figure 44: Box-plot of N-NH4 monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section in simultaneous sampling days during 1996 200582

Figure 45: Box-plot of N-NO3 monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section in simultaneous sampling days during 1996 200583

Figure 46: Box-plot of BOD5 monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section in simultaneous sampling days during 1996 200584

Figure 47: Box-plot of COD-Cr monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section in simultaneous sampling days during 1996 200585

Figure 48: Box-plot of P-PO4 monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section in simultaneous sampling days during 1996 200586

Figure 49: Box-plot of TP monthly concentrations measured by BG and RO in Chiciu / Silistra transboundary section in simultaneous sampling days during 1996 200587

Figure 50: Water temperature data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo89

Figure 51: Suspended solids data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo89

Figure 52: Dissolved Oxygen data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo90

Figure 53: pH data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo90

Figure 54: Electrical conductivity data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo91

Figure 55: N-ammonium data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo91

Figure 56: N-nitrite data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo 92

Figure 57: N-nitrate data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo92

Figure 58: Total N data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo 93

Figure 59: P-orto-phosphates data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo93

Figure 60: Total P data comparability by box-plot during January September 2014 for the transboundary section Pristol / Novo Selo 94

Figure 61: Water temperature data comparability by each measurement during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 37595

Figure 62: Conductivity data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 37596

Figure 63: Dissolved Oxygen data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 37596

Figure 64: pH data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 37597

Figure 65: Suspended Solids data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 37597

Figure 66: N-ammonium data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 37598

Figure 67: N-nitrite data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 37598

Figure 68: N-nitrate data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 37599

Figure 69: Total Nitrogen data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 37599

Figure 70: P-ortho-phosphates data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 375100

Figure 71: Total P data comparability during January September 2014 for the transboundary section Chiciu (RO) / Silistra (BG) km 375100

1. Sub-activity 5.1.: Acquisition of necessary reagents and equipment sets

Based on the projects detailed description, the first sub-activity of the Activity 5 refers to the acquisition of necessary equipment sets, reagents and accessories, which are listed in Table 1. According to the tendering procedures, most of the foreseen equipment and goods were purchased and delivered to the eligible laboratories. Annex 1 of the current Final Report presents several specific outputs (instrumental recordings, calibration curves for UV-VIS Spectrophotometers, TOC-TN analyzers, AAS analyzer etc).

The dedicated laboratory equipment was aimed to cover the main tasks foreseen within the transboundary monitoring programme along the common Bulgarian-Romanian stretch of the Danube River (sampling, storage and conservation, sample preparation, analysis, quality assurance and quality control) for both biological and chemical monitoring. In Figures 1-6 main laboratory equipment purchased within this sub-activity are shown.

Figure 1 (left): Chemical oxygen consume unit (budgetary line V.22.8) for determination of Chemical Oxygen Demand (COD) by potassium dichromate

Figure 2 (above): Ultrasonic bath (budgetary line V.18.13) for sampling preparation

The complete list of laboratory equipment that had been foreseen to be purchased within Activity 3 is In Table 1.

Figure 3: TOC/TN analyzer (budgetary line V.22.11) used for analysis of the following water parameters: Total Organic Carbon (TOC), Dissolved Organic Carbon (DOC), Total Nitrogen (TN)

Figure 4: Atomic Absorbtion Spectrophotometer (budgetary line V.18.7) used for analysis of heavy metals

Figure 5: UV-VIS Spectrophotometer (budgetary line V.18.6) used for analysis of nutrients forms (N-NH4, N-NO2, N-NO3, P-PO4, Total P)

Figure 6: Gas Chromatograph with FID Detector (budgetary line V.18.8) used for analysis of Hydrocarbon Oil Index

Table 1: Equipment and reagents foreseen to be purchased within the sub-activity 5.1 of Activity 5

Category

Expenditure

Unit

Quantity

Status

Delivered to Water Quality laboratory / ship / ANAR

V

EQUIPMENT AND GOODS

V.14

Ship laboratory for analysis of water and sediments samples

V.14.1

Automatic titrator

piece

1,00

Purchased

Giurgiu / ship

V.14.2

Spectrophotometer

piece

1,00

Purchased

Giurgiu / ship

V.14.3

2 refrigerators samples

piece

2,00

Purchased

Giurgiu / ship

V.14.4

2 frozen samples

piece

2,00

Purchased

Giurgiu / ship

V.14.5

Acids and solvents niches

piece

1,00

Purchased

Giurgiu / ship

V.14.6

Sitar system

set

1,00

Not purchased

-

V.14.7

Spin Laboratory centrifuge

piece

1,00

Purchased

Giurgiu / ship

V.14.8

Sampling equipment

set

1,00

Not purchased

-

V.14.9

Microscope

piece

1,00

Purchased

Giurgiu / ship

V.14.10

Invertoscope

piece

1,00

Purchased

Giurgiu / ship

V.14.11

Boat + engine + accessories

set

1,00

Purchased

Giurgiu / ship

V.14.12

pH meter + temperature sensor

set

1,00

Purchased

Giurgiu / ship

V.14.13

Conductometer

piece

1,00

Purchased

Giurgiu / ship

V.14.14

Dissolved oxygen probe

set

1,00

Purchased

Giurgiu / ship

V.14.15

Two filtration systems

piece

2,00

Purchased

Giurgiu / ship

V.14.16

Laboratory glassware

set

1,00

Purchased

Giurgiu / ship

V.14.17

Automatic pipettes, dispensers, burettes

set

1,00

Purchased

Giurgiu / ship

V.14.18

Ciorpac, Secchi disk

set

1,00

Not purchased

-

V.14.19

Oxygenometer

piece

1,00

Purchased

Giurgiu / ship

V.17

Equipment for hydrologic and hydrometric stations

V.17.6

Photometer

piece

20,00

Purchased

7 labs inthe eligible area

V.17.7

Multiparameter

piece

20,00

Purchased

7 labs in the eligible area

V.18

Laborator equipment acquisition

V.18.1

Microscope

piece

2,00

Not purchased

-

V.18.2

Bentoflurometer for a chlorophyll

piece

1,00

Not purchased

-

V.18.3

Conductometer

piece

2,00

Purchased

Calarasi, Alexandria

V.18.4

Shaker

piece

2,00

Purchased

Bucuresti, Calarasi

V.18.5

Bidistillator

piece

1,00

Purchased

Calarasi

V.18.6

UV-VIS Spectrophotometer

piece

2,00

Purchased

Craiova, Constanta

V.18.7

Atomic Absorbtion Spectrometer

piece

2,00

Purchased

Craiova, Bucuresti

V.18.8

Chromatograph with head space and FID detector

piece

2,00

Purchased

Bucuresti

V.18.9

Unity for protection the electric system

piece

2,00

Not purchased

-

V.18.10

Autosampler for automatic extraction of organic pollutants

piece

4,00

Not purchased

-

V.18.11

Digestion vessels for mineralization

piece

4,00

Not purchased

-

V.18.12

Equipment for acid purification

piece

3,00

Not purchased

-

V.18.13

Ultrasonic cleaning bath

piece

2,00

Purchased

Craiova, Bucuresti

V.18.14

Refrigerator

piece

2,00

Purchased

Bucuresti

V.18.15

Oven

piece

1,00

Purchased

Bucuresti

V.22

Inter-calibration of the regional water quality laboratories, in conformity with WFD implementation adequate equipment acquisition, materials and consumables

V.22.1

Software for evaluate the test results

piece

1,00

Purchased

ANAR

V.22.2

Certified reference materials (CRM)

piece

1,00

Purchased

Bucuresti

V.22.3

Standards and reference Materials (RM)

piece

1,00

Purchased

Bucuresti

V.22.4

UV-VIS Spectrophotometer

piece

1,00

Bucuresti

V.22.5

Equipment for acid purification

piece

1,00

Not purchased

V.22.6

Complete system for phenol evaluation

piece

1,00

Purchased

Bucuresti

V.22.7

Complete system unit for cyanides evaluation

piece

1,00

Purchased

Bucuresti

V.22.8

Chemical oxygen consume unit

piece

1,00

Purchased

Bucuresti

V.22.9

Multi-parameter instrument

piece

1,00

Purchased

Calarasi

V.22.10

Hot plate thermostatic

piece

1,00

Purchased

Craiova

V.22.11

TOC/TN analyzer

piece

1,00

Purchased

Bucuresti

V.22.12

Unit for filtration in the field

piece

1,00

Purchased

Craiova

V.22.13

Sampler for water tip Kemmerer

piece

1,00

Not purchased

V.22.14

Shaker for funnels

piece

1,00

Purchased

Bucuresti

V.22.15

Bidistillater

piece

1,00

Purchased

Bucuresti

V.22.16

Invertoscope

piece

1,00

Not purchased

-

V.22.17

Lamps for AAS

piece

1,00

Purchased

Bucuresti

VI.6

Other reasonable costs associated with the direct delivery of the project

VI.6.1

Multi-parameter kit

set

1,00

Not purchased

-

VI.6.2

Microbiology kit

set

1,00

Purchased

Constanta

VI.6.3

Reagents

set

1,00

Purchased

labs in the eligible area

Items under Not purchased status are items for which either no bidders were available at the time of the tender procedure or were depended on the Addendum 5 approval. Because this approval was delayed, the tender procedure could not be resumed in due time for the final implementation project deadline.

2. Sub-activity 5.2.: Water Quality analysis for laboratory intercalibration

Current definition at the EU level given by the WFD Guidance Documents is that intercalibration process is aimed at consistency and comparability of the classification results of the monitoring systems operated by each Member State for the biological quality elements (CIS Guidance Document no. 14 Guidance on the intercalibration Process 2004 2006). The intercalibration exercise must establish values for the boundary between the classes of high and good status, and for the boundary between good and moderate status, which are consistent with the normative definitions of those class boundaries given in Annex V of the WFD. This definition is not in accordance with the objectives of the Danube Water Project. From the metrological point of view, (inter)calibration is to determine, check, or rectify the graduation of any instrument giving quantitative measurements (http://dictionary.reference.com/browse/intercalibration).

Intercalibration has a strict metrological definition, but in brief, its an open sharing of methods and results between laboratories to achieve the most accurate data with the fewest random and systematic errors (Cutter, 2013).

In the context of the WATER project, the proper definition for intercalibration has to be extended to a state achieved by a group of laboratories engaged in a monitoring program in which they produce and maintain compatible data outputs (McGraw-Hill Dictionary of Scientific & Technical Terms, 2003).

2.1. Objectives of laboratories intercalibration

Intercalibration comprises the process, procedures and activities used to ensure that the several laboratories engaged in a monitoring program can produce compatible data. When compatible data outputs are achieved and this situation is maintained, the laboratories can be said to be intercalibrated (Taylor, 1987).

Intercalibration therefore is an active process between laboratories that includes all steps from sampling to analyses, with the goal of achieving the same accurate results regardless of the method or laboratory.

All water testing laboratories in both countries (Bulgaria and Romania) are accredited laboratories according to ISO/IEC 17025:2005. In this line, quality assurance and quality system are in place in each accredited laboratory. Thus, because of technical competences of the lab the objective is (partially) achieved.

In the last period of time, the accreditation process has had a rapid progress involving the updating of the standard ISO documents and the move to accreditation of proficiency testing scheme providers and reference material producers. As a consequence of both of development areas we are now seeing accreditation bodies beginning to insist on the use of proficiency testing schemes which are ISO 17043:2010 accredited and on the purchase of reference materials which are from ISO Guide 34:2009 accredited organisations which have ISO 17025 accredited laboratories.

2.2. Main types of laboratories intercalibration

According to ISO/IEC 17025 a laboratory shall have quality control procedures for monitoring the validity of tests and calibrations undertaken. This monitoring may include the participation in interlaboratory comparisons or proficiency testing schemes (PT). Other means may include the regular use of reference materials, or replicate tests or calibrations using the same or different methods. By these mechanisms a laboratory can provide evidence of its competence to its clients, interested parties and the accreditation body (International Laboratory Accreditation Cooperation (ILAC) Policy for Participation in PT Activities (ILAC-P9:06/2014).

2.2.1. Proficiency Testing (PT) schemes2.2.1.1. General aspects

According to the definition from ISO/IEC 17043:2010 and ILAC-P9:06/2014, the Proficiency testing (PT) is the evaluation of participant performance against pre-established criteria by means of interlaboratory comparisons. Therefore, one of the elements by which accredited laboratories can demonstrate technical competence is by satisfactory participation in PT activities where such activities are available and appropriate.

Proficiency testing schemes is a tool to demonstrate laboratory competence and to assist in maintaining the quality of the laboratory performance (International Laboratory Accreditation Cooperation (ILAC) Policy for Participation in PT Activities (ILAC-P9:06/2014). There are minimum requirements for level and frequency of participation in PT by accredited laboratories, including the need for a PT participation plan which has been formulated by the laboratory and is regularly reviewed in response to changes in staffing, methodology, instrumentation etc.

The PT participation and performance (in particular consistent poor performance) are reviewed and utilized during the assessment and accreditation decision-making process. This may also include possibilities of varied surveillance intervals where performance is consistently good.

In response to poor performances in PT the laboratories have to carry on different corrective actions for improving the results and then to notify of this performance to the accreditation body.

Another important issue is to have at the national, regional or international level providers for such PT schemes. As a rule, the laboratories identify and formulate their PT participation needs and plans. After that, the labs will identify the proper sources of PT scheme and will select suitable programs, taking into account the compatibility of sample type and presentation provided in the PT plan, with those that are most commonly handled in the day to day work. The participation in PT could be a tool for education and risk management.

Where certified reference materials are not available (especially in the case of particular analysis domain or certain matrix) several alternative strategies exist but the main approach is participation in interlaboratory proficiency exercises. Such schemes, at least, give a laboratory a measure of its data relative to other similar laboratories and, if organized properly, provide a very effective addition to the use of certified references.

2.2.1.2. Types of Proficiency Testing schemes

Various types of PT schemes are available, each based on at least one element of each of the following 4 categories:

1. a) qualitative: the results of qualitative tests are descriptive and reported on a nominal or ordinal scale;

b) quantitative: the results of quantitative measurements are numeric and are reported on an interval or a ratio scale;

c) interpretive: no measurement is involved. The PT item is a measurement result, a set of data or other set of information concerning an interpretative feature of the participants competence;

2. a) single: PT items are provided on a single occasion;

b) continuous: PT items are provided on a regular basis;

3.a) sequential: PT item to be measured is circulated successively from one participant to the next. In this case the PT item may be returned to the PT provider before being passed on to the next participant in order to determine whether any changes have taken place to the PT item. It is also possible for the participants to converge in a common location to measure the same PT item;

b) simultaneous: in the most common PTs, randomly selected sub-samples from a homogeneous bulk material are distributed simultaneously to participants for concurrent measurement. After reception of the results the PT provider will evaluate, on the basis of statistical techniques, the performance of each individual participant and of the group as a whole.

4. a) pre-measurement: in this type of PT scheme, the PT item can be an item, on which the participant has to decide which measurements should be conducted or a set of data or other information (e.g. a case study);

b) measurement: the focus is specifically on the measurement process;

c) post-measurement: in this type of PT scheme, the PT item can be a set of data on which the participant is requested to give an opinion or interpretation.

One special application of PT, often called blind PT, is where the PT item is indistinguishable from normal customer items or samples received by the participant. All of the types of PT schemes mentioned above could be organised as a blind PT.

2.2.1.3. Use of PT schemes by the laboratory

The basic use of PT for a laboratory is to assess its performance for the conduct of specific measurements or calibrations.

The results and information received from the participation in PT schemes will provide laboratories with either a confirmation that the laboratory's performance is satisfactory or an indication that there are potential problems and those corrections should be made.

However, the use of PT should be much wider than the basic statement of whether the laboratory is competent or not. The laboratories can benefit from the participation in PT schemes in many ways ([footnoteRef:1]): [1: each of the below items are further detailed in the Draft for Intercalibration Guidelines as output of Activity 5]

Identifying Measurement Problems (as a risk management and performance improvement tool)

Comparing Methods or Procedures

Comparing Operator Capabilities

Comparing Analytical Systems

Improving Performance

Educating Staff

Exchange of Information with the PT Provider

Instilling Confidence in Staff, Management, and External Users of Laboratory Services

Measurement Uncertainty

Use of PT items as Internal Quality Controls

Verification of Method Performance.

2.2.1.4. Assessment of results of the PT schemes

The purpose of this section is to present the main aspects of the statistical design used by the PT providers, so that the laboratories can better understand the evaluations performed. This should help the laboratory in the selection of the appropriate scheme and in the interpretation of the results. However, given the range of different techniques used it is not possible for this document to address all statistical aspects. It is important that the design used by the PT provider is appropriate for the type and purpose of the PT scheme being organized. Furthermore, the design used by the PT provider should be fully described to the participants. Preferred statistical techniques have been described in ISO 13528, although other valid approaches can be used.

The underlying assumptions of the statistical approach used in PT schemes are mostly based on the normal distribution of data. However, it is common for the set of participants results, whilst being essentially normally distributed, to be contaminated with heavy tails and a small proportion of outliers. The original approach used by PT providers (and still used in some PT schemes) was to use statistical tests to identify the presence of outliers from the data set. However, the more common approach now used by PT providers, as recommended in ISO 13528, is to use robust statistics. Robust statistics has the advantage of reducing the contribution of outliers to the calculated statistical parameters such as the mean and standard deviation. There a number of robust statistical approaches, some of which are described in ISO 13528.

Basic elements

One of the basic elements in all PTs is the evaluation of the performance of each participant. In order to do so, the PT provider has to establish basically two values, which are used for the performance evaluation:

1. The assigned value.

2. The standard deviation for proficiency assessment.

In addition the PT provider would be expected to provide an estimate of the measurement uncertainty and a statement of the metrological traceability of the assigned value, as this concept has been included in ISO/IEC 17043. The relevance, need and feasibility of this estimation shall be determined by the design of the PT scheme.

Different methods can be used to establish these values. There is no strict standardised protocol, which prescribes in detail the statistical design to be used, however this design should be in substantial agreement with the designs described in the reference documents. The statistical design should be documented by the PT provider, normally either in the scheme protocol or/and in the PT description.

1. Assigned value

As described in ISO 13528, essentially five methods are available to obtain the assigned value, a working estimate of the true value:

Formulation.

Certified reference values.

Reference values.

Consensus values from expert laboratories.

Consensus value from participants.

This issue is one of the most critical features of a PT! Inappropriate value will drastically reduce the value of the scheme!

ISO/IEC 17043:2010 standard, point 4.4.5.1 underlines that the PT provider shall document the procedure for determining the assigned values for the measurands or characteristics in a particular PT scheme.

2. Standard deviation for proficiency assessment

There are, as described in ISO 13528, essentially five approaches to determine the standard deviation for proficiency assessment, i.e. the acceptable range of participant results:

Prescribed value.

By perception.

From a general model.

From the results of a precision experiment.

From data obtained in round of a PT scheme.

At present a common way to establish the assigned value and the standard deviation for proficiency assessment is the use of the participants PT results to calculate both values.

Thus wherever possible, the PT provider should base the standard deviation for proficiency assessment on a fit for purpose value rather than a value that will change from round to round, depending on the spread of the results submitted by the participants. Using a fit for purpose value will facilitate the monitoring of performance scores over successive rounds of the PT scheme.

Performance evaluation

Performance evaluation (or score) by the PT provider adds value to the raw analytical results produced by the participant. The purpose of providing a normalised performance evaluation is to make all PT results comparable, so that the participant can immediately appreciate the significance of the evaluation.

The use of measurement uncertainty in the performance evaluation is increasing as the understanding of this aspect is improving. Two types of measurement uncertainty can be taken into account:

1. Measurement uncertainty of the assigned value.

2. Measurement uncertainty of the participant result.

Given the diverse purposes of PT schemes it is not possible to define a single universal evaluation method. Therefore, a number of statistical designs used for the evaluation of performance are available.

The most common ways are listed below[footnoteRef:2]: [2: For each asseessment statistical design details (formulas and ways of interpretation are given in the Draft for Intercalibration Guidelines as output of Activity 5]

1. Z score (most commonly used, measurement uncertainty is not taken into account).

2. Z- score (standard uncertainty of the assigned value is taken into account).

3. Zeta score (standard uncertainty of the assigned value and the participants result is taken into account.

4. En number (expanded uncertainty of the assigned value and the participants result is taken into account).

Taking into account that most of the PT schemes are based on the z score values t, the following criteria are applied in the assessment:

z 2,0 the score indicates satisfactory performance and generates

no signal

2.0 < z < 3.0 the score indicates questionable performance and generates a warning signal

z 3.0 the score indicates unsatisfactory performance and generates an action signal

Taking part in a PT scheme is of limited value unless the laboratory takes advantage of its performance evaluation and the general information given in the PT scheme report. It is important that the laboratory not only acknowledges the performance evaluation obtained, but evaluates and interprets it, avoiding any misinterpretations or over-interpretations. The evaluation of the performance from the laboratory should be done after each round, and for continuous schemes the performance over time should also to be evaluated.

2.2.2. Specific Laboratory intercomparisons

In the issue of specific laboratory intercomparisons transboundary QA/QC schemes, bilateral agreements between neighboring countries and common or parallel actions during different types of activities can be included: research projects, investigative monitoring (i.e. Joint Danube Surveys). The subject of transboundary PT schemes will be developed below.

2.2.2.1. Comparisons under Investigative Monitoring JDS type

Joint Danube Surveys (JDS) were the biggest river research expeditions in the world at those moments. JDS catalyzed international cooperation from all 14 of the main Danube Basin countries and the European Commission. The JDS is carried out every six years JDS1 was in 2001, JDS2 in 2007 and JDS3 in 2013. Some specific objectives of the surveys have been underlined:

to produce a homogenous data set for the Danube River based on a single sampling procedure and laboratory analysis of specified determinands and biological quality elements;

to provide a forum for riparian/river basin country participation for sampling and inter-comparison exercises;

to facilitate specific training needs and improve in-country experience;

harmonization of sampling methods for quality elements etc.

Results as well as conclusions and lessons learned from this type of investigation can be found and documented on the website of the International Commission for the Protection of the Danube River (www.icpdr.org).

2.2.2.2. Intercomparisons under Regular Transboundary Exercises

The organisation of interlaboratory comparison in the Bucharest Declaration Danube monitoring was agreed in 1992. Until 2012, the Institute for Water Pollution Control of VITUKI, Budapest, Hungary, offered and took the responsibility for organising the first study under the name of Qualco-Danube. From avery few determinands analysed during the first distribution pH, conductivity and total hardness - in 1993, both the range of determinands and anetwork of participating laboratories were being extended.

The main objective of PT scheme Qualco Danube was to establish and to implement the primary inter-laboratory quality control program in the Danube basin. The PT scheme Qualco-Danube started in 1993, extended in 1995 to 11 National Reference Labs (NRLs) and from 1996 to 19 NRLs. The provider was the Institute for Water Pollution Control of VITUKI, Budapest, Hungary (until 2012) and WESSLING (HU) (from 2013 until present).

The analytical methodologies for the determinands applied in TNMN are based on a list containing reference and optional analytical methods. The National Reference Laboratories (NRLs) have been provided with a set of ISO standards (reference methods) reflecting the determinand lists, but taking into account the current practice in environmental analytical methodology in the EU. It has been decided not to require each laboratory to use the same method, providing the laboratory would be able to demonstrate that the method in use (optional method) meets the required performance criteria. Therefore, the minimum concentrations expected and the tolerance required of actual measurements has been defined for each determinand, in order to enable laboratories to determine whether the analytical methods currently in use are acceptable:

The minimum likely level of interest is the lowest concentration considered likely to be encountered or important in the TNMN.

The principal level of interest is the concentration at which it is anticipated that most monitoring will be carried out.

The required limit of detection is the target limit of detection (LOD) which laboratories are asked to achieve. This has been set, wherever practicable, at one third of the minimum level of interest. This is intended to ensure that the best possible precision is achieved at the principal level of interest and that relatively few "less than results" will be reported for samples at or near the lowest level of interest. Where the performance of current analyses is not likely to meet the criterion of a LOD of one third of the lowest level of interest, the LOD has been revised to reflect best practice. In these cases, the targets have been entered in italics.

The tolerance indicates the largest allowable analytical error which is consistent with the correct interpretation of the data and with current analytical practice. The target is expressed as x concentration units or P%. The larger of the two values applies for any given concentration. For example, if the target is 5 mg.L-1 or 20% - at a concentration of 20 mg.L-1 the maximum tolerable error is 5 mg.L-1 (20% is 4 mg.L-1); at a concentration of 100 mg.L-1, the tolerable error is 20 mg.L-1 (i.e. 20%) because this value exceeds the fixed target of 5 mg.L-1.

Table 2: Analytical performances required for selected determinand list for water quality within TNMN

Determinands in Water

Unit

Minimum likely level of interest

Principal level of interest

Target Limit of Detection

(LOD)

Tolerance

Ammonium (NH4+ -N)

mg.L-1

0.05

0.5

0.02

0.02 or 20%

Nitrate (NO3- -N)

mg.L-1

0.2

1.0

0.1

0.1 or 20%

Ortho- Phosphate (PO43- -P)

mg.L-1

0.02

0.2

0.005

0.005 or 20%

Total Phosphorus (TP)

mg.L-1

0.05

0.5

0.01

0.01 or 20%

BOD5

mg.L-1

0.5

5.0

0.5

0.5 or 20%

COD - Cr

mg.L-1

10

50

10

10 or 20%

It is good practice that targets for analytical accuracy define the standard of the accuracy which is necessary for the task in hand. Therefore, two key concentration levels - the minimum level of interest and the principal level of interest - have been defined for each determinand. These levels define the aims of the monitoring programme and can be used to establish the performance needed from analytical systems used in the laboratories involved in the TNMN, assuming that the aims of the programme will be satisfied provided:

that relatively few results are reported as less than the minimum level;

that the accuracy achieved at the principal level is not worse than 20% of the principal level.

Any practical approach to monitoring must take into account the current capabilities of analytical science. This means that if some targets are recognized as very difficult to achieve, it may be necessary to set more relaxed, interim targets and to review performance and data use in the course of the monitoring programme.

The described approach supports the work of harmonizing the analytical activities within the Danube Basin related to the TNMN as well as the implementation and operation of an Analytical Quality Control (AQC) programme. Therefore, it has been used in development of the training needs required to improve the laboratory performance of the National Reference Laboratories as well as the other laboratories involved in the implementation of the TNMN.

Quarterly distribution every year has been carried out until 2012, analyzing synthetic samples and real water samples. In water samples general determinands like chlorides, sulphates and total hardness, nutrients, heavy metals and determinands characterizing organic pollution - both general and specific determinands were included. Starting from 2013 a flexible distribution (nutrients / every year, heavy metals / every 2 years, organics / every 3 tears) has been taken up.

A general description of the sample preparation and evaluation scheme for AQC in the Danube river basin is given in Figure 7 .

2.2.2.3. Performance assessment in Qualco Danube

Until 2008 (including), the performance assessment was carried out based on the tolerance intervals. Introduced in 1998, the evaluation of performance was based on percentage bias. For this purpose, the difference between the measured value reported by the laboratory (xm) and the assigned value (xa) is calculated first as a percentage of the assigned value. This percentage bias (B%) is compared to pre-set warning and rejection limits, also expressed as percentages (Lw% and Lr% respectively). The performance of the laboratory is then judged as follows:

- if B% = the measured value is acceptable.

- ifB% = and B% = the measured value is assigned a warning sign.

-ifB% =the measured value is rejected.

Figure 7: Sample preparation and evaluation scheme for AQC in the Danube River basin (Five years Report on Water Quality in Danube River Basin Based on Trans-National Montoring Network, 2003)

The exact value of Lw% and Lr% varies with the determinand, the matrix as well as the concentration level in question, but their ratio is set at 1:2.

The QA/QC Directive (2009/90/EC) linked to the Water Framework Directive states the following requirement concerning proficiency testing (PT): "The results of participation in those programmes shall be evaluated on the basis of the scoring system set out in ISO/IEC Guide 43-1 or in the ISO-13528 standard or in other equivalent standards accepted at international level." (Article 6/3, second paragraph). Although the cited standards do include percentage bias as a valid indicator of performance, the ratio of Lw% and Lr% is set at 2:3.

Furthermore, the 2006 survey of European providers of WFD-related proficiency testing schemes found that the overwhelming majority of PT providers uses another performance indicator, the z-scores (described above) (EAQC-WISE Deliverable 14-17, Joint final report on existing AQC tools and services related to PTs and recommendation for gaps). In order to facilitate comparability of laboratory performance in different WFD-related PT schemes in Europe, a harmonised protocol has been prepared by the European network of PT providers, of which VITUKI is a member. The harmonised protocol also endorses the use of z-scores as performance indicators, according to the provisions of ISO 13528:2005(E) Statistical methods for use n proficiency testing by interlaboratory comparisons. Thus, the ICPDR Monitoring and Assessment Expert Group decided, on the initiative of VITUKI, to commit to z-score performance evaluation in 2009:

,

Where:

= the z score;

= the value reported by the laboratory;

= the reference value;

= the standard deviation for proficiency assessment.

The z-score reflects two separate features: (a) the actual accuracy achieved (i.e. the difference between the participant result and the accepted true value), and (b) the scheme organizers judgment of what degree of accuracy is fit for purpose.

Z-scores must be interpreted on a statistical (probabilistic) basis and this requires expert knowledge. An outline of interpretation is given in the followings:

A score of zero implies a perfect result. This will happen quite rarely even in perfectly competent laboratories.

Laboratories complying with the proficiency testing schemes fitness for purpose criterion will commonly produce scores falling between -2 and 2. They might be expect to produce a value somewhat outside this range occasionally by chance, roughly about one time in twenty, so an isolated event of this kind is not of great moment. The sign (i.e. + or -) of the score indicates a positive or negative error respectively.

A score outside the range from -3 to 3 would be very unusual for a laboratory operating under the given fitness for purpose criterion and is it taken to indicate that the cause of the event should be investigated and remedied.

2.2.2.4. Examples of Qualco-Danube results for two danubian laboratories in Romania

The interlaboratory comparative results are discussed below for the two responsible laboratories involved in TNMN (LCA Craiova 1 for Pristol section and LCA Constanta 2 for Chiciu section), separately for the different considered determinands, based on the absolute deviation from the assigned value and the following benchmarks:

Acceptable limit: generally depending on the concentration range for each water quality parameter, between these two limits (positive and negative respectively) the results are acceptable. In the following graphs, depending on the parameter, these limits are set at 10%, 15% or 20%.

Warning limits: the results situated between these limits require that the laboratory should pay more attention to the analytical aspects (either to the way of determination itself or to the analytical method). In the following graphs, depending on the parameter, these limits are set at 20%, 30% or 40%.

Results beyond the warning limits are rejected, usually they indicate that there is an error source (random or systematic) and a mandatory action is required immediately.

As it can be seen from Figures 5 9, the analytical performance of the two responsible laboratories improved continuously from 1998 to 2004, with very few values situated outside the warning limits.

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Figure 8: Evaluation of the analytical quality performance for Laboratory 1 within the Qualco-Danube AQC Scheme during 1998 2004 (N-NH4)

Figure 9: Evaluation of the analytical quality performance for Laboratory 2 within the Qualco-Danube AQC Scheme during 1998 2004 (N-NH4)

Figure 10: Evaluation of the analytical quality performance for Laboratory 1 within the Qualco-Danube AQC Scheme during 1998 2004 (N-NO3)

Figure 11: Evaluation of the analytical quality performance for Laboratory 2 within the Qualco-Danube AQC Scheme during 1998 2004 (N-NO3)

Figure 12: Evaluation of the analytical quality performance for Laboratory 1 within the Qualco-Danube AQC Scheme during 1998 2004 (P-PO4)

Figure 13: Evaluation of the analytical quality performance for Laboratory 2 within the Qualco-Danube AQC Scheme during 1998 2004 (P-PO4)

Figure 14: Evaluation of the analytical quality performance for Laboratory 1 within the Qualco-Danube AQC Scheme during 1998 2004 (P-PO4)

Figure 15: Evaluation of the analytical quality performance for Laboratory 2 within the Qualco-Danube AQC Scheme during 1998 2004 (P-PO4)

2.2.3. Intercomparisons by bilateral agreements2.2.3.1. Objective

As part of bilateral agreement, interlaboratory comparisons and sampling campaigns along Bulgarian-Romanian Danube stretch have been proposed. All details have been set within a Protocol.

The aim of common sampling campaigns and interlaboratory comparison is to harmonize of sampling and analytical procedures used by laboratories from Bulgaria and Romania on the common Danubian stretch, in order to make monitoring data highly comparable.

Moreover, technical specifications for chemical analysis as required by the QA / QC Directive (2009/90/EC) are tested. Based on this European Directive the quality and comparability of analytical results generated by laboratories appointed by competent authorities of the Member States to perform water chemical monitoring pursuant to Article 8 of Directive 2000/60/EC (WFD) should be ensured. Fulfilling these criteria for all water quality parameters required by the WFD is an on-going objective within the laboratory activity and it is able to be fulfilled using high performance analytical equipment.

2.2.3.2. Protocol for bilateral action

An attempt for setting a bilateral action has been proposed within a Protocol that includes sampling sections, investigated matrix, parameters, sampling procedures, laboratories, analytical methods and performance. For each step of the proposed actions, laboratories involved should act according to their own Standardised Operational Procedures, but eventually the obtained results are going to be analysed and discussed through bilateral meetings.

In this regard, within Activity 5, the proposed Protocol was sent to the Bulgarian partner (Executive Agency) for agreement and further actions. For the first step of the common activity a list with 30 parameters has been proposed (see). As a general rule, the frequency and parameters are based on the transboundary programmes requirements.

Table 3: Water Quality parameters proposed to be analyzed during the common intercomparison exercise June 2015. Investigated matrix: water

No.

Water Quality Parameter

Unit

1

Water temperature

0C

2

Suspended solids

mg/l

3

Dissolved Oxygen Concentration

mg/l O2

4

Dissolved Oxygen Saturation

%

5

pH

-

6

Conductivity (@ 200C)

S/cm

7

Alkalinity

mmol/l

8

Ammonium (NH4+-N)

mg/l N

9

Nitrites (NO2--N)

mg/l N

10

Nitrates (NO3--N)

mg/l N

11

Total Nitrogen

mg/l N

12

Ortho-phosphates (PO43--P)

mg/l P

13

Total Phosphorous

mg/l P

14

COD-Cr

mg/l O2

15

BOD5

mg/l O2

16

Calcium (Ca2+)

mg/l

17

Magnesium (Mg2+)

mg/l

18

Clorides (Cl-)

mg/l

19

Cadmium (dissolved)

g/l

20

Lead (dissolved)

g/l

21

Mercury (dissolved)

g/l

22

Nickel (dissolved)

g/l

23

Copper (dissolved)

g/l

24

Zinc (dissolved)

g/l

25

Chromium (dissolved)

g/l

26

Arsenic

g/l

27

Atrazin

g/l

28

Lindan

g/l

29

pp-DDT

g/l

30

Chlorophyll a

g/l

The corresponding sub-activities are being carried out based on the following terms:

a) sampling information:

sampling sections: starting and ending trans-boundary sections respectively of the common Romanian Bulgarian danubian stretch: Pristol (RO) / Novo Selo (BG) (km 834) and Chiciu (RO) / Silistra (BG) (km 375);

cross sections (left, middle, right) sampled

in-situ measurements (Water temperature, Dissolved Oxygen, Conductivity and pH);

sampling according to the internal Standard Operational Procedures of the involved laboratories (prepared based on standardised methods and recognised by the accreditation process);

for each cross section, sampling operations will be carried out in parallel by both teams;

sampling Reports will be filled in by each team according to their own specific templates.

b) Laboratory Analysis

the involved laboratories in both countries are accredited laboratories (SR EN ISO/CEI 17025:2005);

analyses are carried out by each part;

all involved laboratories use standardised and/or in-house validated analytical methods;

compliance of the LOQs with the criteria specified in the D 2009/90/EC might be checked and reported by each part (to be jointly agreed): uncertainty of measurement of 50 % or below (k= 2) estimated at the level of relevant environmental quality standards (EQS) and LOQ equal or below a value of 30 % of the relevant environmental quality standards:

LOQ = 3.3)

Compliance checking based on QA/QC Directive criteria will be carried out for Priority Substances only (4 heavy metals and 3 organic micropollutants), for which EQS at the Community level are set-out by the 2013/39/EC.

c) Results and interpretation

the results will be reports in an Excel template;

analytical results will be shared between parts, in electronic format, according to the commonly agreed deadline. Bilateral meetings for discussions on results and agreement will be take place;

for the interpretation of the results, analysis of results from other PT schemes of interest, investigation of unsatisfactory or questionable PT results and monitoring of PT performance over time are issues of interest.

2.2.3.3. Common Romanian Bulgarian Inter-comparison activity June 2015

Based on the above mentioned Protocol, the common Romanian Bulgarian sampling activity took place according to the following schedule:

On the 8th of June 2015 in sampling section Chiciu (RO) / Silistra (BG) (km 375), responsible laboratory from the Romanian part: Water Quality Laboratory Constana (Dobrogea Water Branch) see Figure 16 .

On the 16th of June 2015 in sampling section Pristol (RO) / Novo Selo (BG) (km 834), responsible laboratory from the Romanian part: Water Quality Laboratory Tr. Severin (Jiu Water Branch) see Figure 17

Figure 16: Common Romanian Bulgarian sampling exercise in Chiciu (RO) / Silistra (BG) (km 375) transboundary section on the 8th of June 2015. Left: sampling recipients dedicated to heavy metals analyses according to the SOP. Right: Romanian team from the Dobrogea Water Branch meeting the Bulgarian team

Figure 17: Common Romanian Bulgarian sampling exercise in Pristol (RO) / Novo-Selo (BG) (km 834) transboundary section on the 16th of June 2015. Romanian team from the Jiu Water Branch meeting the Bulgarian team

Taking into account the timing (mid of June) of the common Romanian Bulgarian intercomparison exercise, the results of the corresponding analyses will be available not earlier than the 10th of July 2015. Therefore, the data exchange, discussions and agreement of the final results of the exercise will be consequently delayed (results will be included in Annex of this Final Report in due time).

3. General aspects on the cooperation in the Danube River basin

The Danube River flows through ten countries, and its large river basin of 817 000 km2 is shared between 17 countries. The waters in Danube River Basin serve people for many purposes drinking water preparation, use for industrial and agricultural activities, recreation, hydropower generation, and navigation. Very important function of the rivers in Danube River Basin is its ecological function, to which attention is growing also due to the latest development of EU legislation. On the other hand human activities result in discharging of waste waters, release of pollutants from diffuse sources, change of natural habitats for aquatic biota and risk of accidental pollution. To protect waters in the Danube River Basin and to ensure their functions and sustainable human uses, cooperation of Danubian states is inevitable.

The Danube River Protection Convention (DRPC), signed in 1994 and entering into force in 1998, creates the basis for such cooperation. Its main objective is to achieve sustainable and equitable water management, including conservation, improvement and the rational use of surface and groundwater. Danubian countries shall take all appropriate legal, administrative and technical measures to at least maintain and improve environmental and water quality conditions of the Danube River and of waters in its catchment area.

To be able to assess the progress in improvement of environmental conditions of waters in Danube River basin, and to assess effectiveness of measures set up, the role of information from water quality monitoring is crucial. The Danube River Protection Convention says that the Contracting Parties shall cooperate in the field of monitoring and assessment. For this aim they shall harmonise or make comparable their monitoring and assessment methods and shall periodically assess the quality conditions of Danube River and the progress made by taken measures.

As one of the tools for implementation of DRPC, Joint Action Programme for the Danube River Basin (JAP) had been prepared defining the integrated measures for improvement of the environment related to the waters in the Danube River Basin. Danubian States and Permanent Secretariat of ICPDR had developed JAP for period of years 2001-2005. In relation to basin-wide cooperation in the field of monitoring JAP stresses necessity to prepare the data in such a way that allows using them in comparative way and serving as a reliable basis for making decisions throughout the Basin.

Presented report would like to contribute to fulfil the above-mentioned requirements on information related to the quality of waters in Danube River Basin. It contains assessment of the data, collected by Danubian countries in the period of years 1996-2000 in the frame of joint Transnational monitoring network (TNMN).

Taking into account the output of this activity (data comparability) it was consider that, besides the data obtained by the bilateral BG-RO exercise of sampling and analysis from 2013, also previous investigative data as well as long-term monitoring data for the sampling stations located on the Danube common sector should be considered, namely the Transnational monitoring network (TNMN).

3.1. History of TNMN

The first steps towards joint water quality monitoring network in Danube River basin were taken when governments of the Danube countries signed the Bucharest Declaration. The monitoring network used for the purposes of the Declaration consisted of eleven monitoring locations and were located on the Danube River itself where the river formed or crossed the border between the countries.

In 1991 the Danubian countries started preparation of the Convention on cooperation for the protection and sustainable use of the Danube River (DRPC), which was signed in 1994.

The Environmental Programme for the Danube River Basin, led by a Task Force, also started in 1991 with the main objective to strengthen the operational basis for environmental management in the Danube River Basin and to support the Danubian countries to implement the DRPC.

In 1992, the Task Force agreed a three-year Work Plan (1992-1995) with monitoring, laboratories and information management having between the main Programme actions. In 1992 the Monitoring, Laboratory and Information Management Sub-Group (MLIM-SG) was established to deal with this topic.

The main outcome of the three-year Work Plan was the Strategic Action Plan (SAP). Its approval marked the end of the first phase of the EPDRB (1992-1995) and implementation was scheduled to start in the next phase (1996-2000).

The TNMN was originally designed in 1993 during the project Monitoring, Laboratory Analysis and Information Management for the Danube River Basin, conducted by the WTV Consortium in close cooperation with MLIM-SG.

The responsibility for TNMN was assigned to MLIM-SG, which consisted of three Working Groups Monitoring WG, Laboratory Management WG and Information Management Working Group. MLIM-SG should address the development of water quality monitoring network in Danube River Basin; introduce harmonised sampling procedures and enhanced laboratory analysis capabilities; and form the core of a Danube information system on the status of in-stream water quality. The 1996 and 1997 budgets of Phare Multi-Country Environmental Programme allocated substantial funds to EPDRB projects to support further development of the monitoring and assessment programme and the launch of TNMN into operation.

After entry of the DRPC into force in October 1998, MLIM-Expert Group was incorporated in the organisational structure of International Commission for the Protection of the Danube River (ICPDR) and has been working on the basis of TORs agreed by the ICPDR Plenary Meeting. In accordance with the TORs, the overall objective of the MLIM-EG is to create a strengthened and more strategic approach to monitoring, laboratory and information management for surface waters. The key role of the Group is to address the organisational and operational aspects related to the monitoring of water riverine conditions in the Danube River Basin and to provide basic data as an input to the ICPDR information system.

3.2. Description of TNMN 3.2.1. Objectives of TNMN

TNMN has been designed with purpose to meet the main objectives defined for monitoring network in Danube River Basin by the Work Plan of EPDRB. The Work Plan states that the monitoring network shall:

strengthen the existing network set up by the Bucharest Declaration;

be capable of supporting reliable and consistent trend analysis for concentrations and loads for priority pollutants;

support the assessment of water quality for water use;

assist in the identification of major pollution sources;

include sediment monitoring and bioindicators;

include quality control.

Furthermore, the Work Plan provides that:

the monitoring network shall provide outputs compatible with those in other major international river basins in Europe;

the monitoring network shall in future comply with standards used in the western part of Europe;

the monitoring network shall be designed in a way to reflect immediate and long-term needs - starting with practical and routine functions already performed.

As it was already mentioned, the TNMN was originally designed in 1993 during the project conducted by WTV Consortium. The implementation was agreed by MLIM-SG, but the design was further simplified for operation in the first phase, starting in 1996. The first phase is seen as a period with:

the operation of a limited number of stations with defined objectives already included in national monitoring networks according to defined objectives;

a determinand lists reflecting the Bucharest Declaration and EU-Directives;

an information management based on a simple data exchange file format between the riparian countries.

3.2.2. Revision of the TNMN to meet the objectives of EU Water Framework Directive (2000/60/EC) (Yearbook, 2011)

The original objective of the TNMN was to strengthen the existing network set up by the Bucharest Declaration, to enable a reliable and consistent trend analysis for concentrations and loads of priority pollutants, to support the assessment of water quality for water use and to assist in the identification of major pollution sources.

In 2000, having the experience of the TNMN operation, the main objective of the TNMN was reformulated: to provide a structured and well-balanced overall view of the status and long-term development of quality and loads in terms of relevant constituents in the major rivers of the Danube Basin in an international context.

Implementation of the EU Water Framework Directive (2000/60/EC, short WFD) after 2000 necessitated the revision of the TNMN in the Danube River Basin District. In line with the WFD implementation timeline, the revision process has been completed in 2007.

The major objective of the revised TNMN is to provide an overview of the overall status and long-term changes of surface water and where necessary groundwater status in a basin-wide context with a particular attention paid to the transboundary pollution load. In view of the link between the nutrient loads of the Danube and the eutrophication of the Black Sea, it is necessary to monitor the sources and pathways of nutrients in the Danube River Basin District and the effects of measures taken to reduce the nutrient loads into the Black Sea.

To meet the requirements of both EU WFD and the Danube River Protection Convention the revised TNMN for surface waters consists of following elements:

Surveillance monitoring I: Monitoring of surface water status

Surveillance monitoring II: Monitoring of specific pressures

Operational monitoring

Investigative monitoring

Surveillance monitoring II (SM II) is a joint monitoring activity of all ICPDR Contracting Parties that produces annual data on concentrations and loads of selected parameters in the Danube and major tributaries.

This Report is based on the monitoring data provided within the SM II.

Surveillance monitoring I and the operational monitoring is based on collection of the data on the status of surface water and groundwater bodies in the DRB District to be published in the DRBM Plan once in six years.

Investigative monitoring is primarily a national task but at the basin-wide level the concept of Joint Danube Surveys was developed to carry out investigative monitoring as needed, e.g. for harmonization of the existing monitoring methodologies, filling the information gaps in the monitoring networks operating in the DRB, testing new methods or checking the impact of new chemical substances in different matrices. Joint Danube Surveys are carried out every 6 years.

Detailed description of the revised TNMN is given in the Summary Report to EU on monitoring programmes in the Danube River Basin District designed under WFD Article 8.

Every year, the Yearbook presents the results of the Surveillance monitoring II: Monitoring of specific pressures.

3.2.3. Network of monitoring locations

The monitoring network in the frame of TNMN builds on national surface water monitoring networks. To select monitoring locations for the purposes of international monitoring network in Danube River Basin, respecting also the above-mentioned TNMN objectives, the following concrete selection criteria for monitoring location had been set up:

located just upstream/downstream of an international border;

located upstream of confluences between Danube and main tributaries or main tributaries and larger sub-tributaries (mass balances);

located downstream of the biggest point sources;

located according to control of water use for drinking water supply.

Monitoring location included in TNMN should meet at least one of the selection criteria.

The sites are located in particular on the Danube and its major primary or secondary tributaries near crossing boundaries of the Contracting Parties. SM II monitoring sites are presented in Figure 18.

4. Materials and methods4.1. Monitoring stations

In order to check the data comparability provided by the two partner countries within the TNMN network (BG-RO), two pairs of transboundary monitoring sections were selected out of the 11 sections located on the BG RO Danubian common stretch the monitoring.

Table 4: List of TNMN monitoring sites located on the common BG RO Danubian stretch within the TNMN network

No

Country code

TNMN code

River

Name of site

Locations

x- coord.

y-coord.

River-km

Altitude

Catch-ment

1

BG

BG1

Danube

Novo Selo

LMR

22.785

44.165

834

35

580 000

2

BG

BG9

Danube

Lom

R

23.270

43.835

741

24

588 860

3

BG

BG10

Danube

Orjahovo

R

23.997

43.729

679

22

607 260

4

BG

BG2

Danube

Bajkal

R

24.400

43.711

641

20

608 820

5

BG

BG11

Danube

Nikopol

R

25.927

43.701

598

21

648 620

6

BG

BG3

Danube

Svishtov

R

25.345

43.623

554

16

650 340

7

BG

BG4

Danube

Upstream Russe

R

25.907

43.793

503

12

669 900

8

BG

BG5

Danube

Silistra

LMR

27.268

44.125

375

7

698 600

9

RO

RO2

Danube

Pristol / Novo Selo

LMR

22.676

44.214

834

31

580 100

10

RO

RO3

Danube

Upstream Arges (Oltenita)

LMR

26.619

44.056

432

16

676 150

11

RO

RO4

Danube

Chiciu/Silistra

LMR

27.268

44.128

375

13

698 600

Distance:The distance in km from the mouth of the mentioned river

Altitude:The mean surface water level in meters above sea level

Catchment:The area in square km, from which water drains through the station

Sampling location in profile:

L: Left bank

M: Middle of river

R: Right bank

This report takes into account the monitoring data measured in stations located at the start and at the end of the common Danubian stretch, namely the transboundary sections Pristol (RO2) / Novo Selo (BG1) - river km 834 and Chiciu (RO4) / Silistra (BG5) river km 375 respectively (red highlighted in Table 4).

4.2. Data collection and processing

The present chapter takes into account measured concentrations (mg.L-1) during 1996 2005 for four dissolved nutrients forms and two organic pollution indicators: N-ammonium (N-NH4), N-nitrates (N-NO3), P-orthophosphates (P-PO4), Total Phosphorous (TP), Bio-chemical Oxygen Demand in 5-days (BOD5) and Chemical Oxygen Demand by Potassium Dichromate (COD-Cr). Data set was produced in the frame of TNMN programme. Within TNMN monitoring data is yearly collected at the national level by the National Data Managers (NDMs) who are in charge with data checking, conversion into an agreed data exchange file format (DEFF) and sending it to the TNMN data management center in the Slovak Hydrometeorological Institute in Bratislava. This center performs an additional data validation and uploads them into the central TNMN database. In cooperation with the ICPDR Secretariat, the TNMN data are uploaded into the ICPDR website (www.icpdr.org) (TNMN Yearbook, 2010). The primary monitoring dataset used in this report are extracted from the TNMN database, restricted area, www.icpdr.org.

For each parameter, data processing includes the calculation of basic descriptive statistics (mean, median, minimum, maximum, lower and upper quantiles, 10 and 90 percentile (C10 and C90), skewness and kurtosis (not shown in the chapter). When the concentration of a certain parameter was below the limit of detection (LOD) reported by laboratory, the measurement result was set to half of the LOD. Starting with 2008 data was sent according to the Directive 2009/90/EC, with limit of quantification (LOQ) instead LOD. Therefore, values below LOQ were replaced by half of this limit (where available).

For the considered stations with three sampling locations on profile (left bank, middle and right bank) only the results recorded in the middle were processed.

The data comparability was checked in two different situations:

for the entire data set recorded in the two sampling stations during the considered time period;

for the simultaneous sampling dates

For statistical analysis and graphics, the software packages STATISTICA 7.0 (StatSoft. Inc., 2005) Origin 8.0 and Microsoft Office Excel were used.

Table 5: Analytical standards methods used within TNMN Programme for selected water quality parameters

Parameter

Standard Method

Analytical Principle

Limit of

Detection LOD

(mg.L-1)

Limit of Quantification LOQ

(mg.L-1)

N NH4

SR ISO 7150-1/2001

Spectrometric measurement at 655 nm of the blue compound formed by reaction of ammonium with salicylate and hypochlorite ions in the presence of sodium nitrosopentacyanoferrate (III) (sodium nitroprusside)

0.003

0.010

N NO3

SR ISO 7890-3/2000

Spectrometric measurement of the yellow compound formed by reaction of sulfosalicylic acid (formed by addition to the sample of sodium salicylate and sulphuric acid) with nitrate and subsequent treatment with alkali

0.01

0.04

P PO4

ISO 6878/2005

Ammonium molybdate and potassium antimonyl tartrate react in acid medium with orthophosphate to form a heteropoly acid (phosphomolybdic acid) that is reduced to intensely coloured molybdenum blue by ascorbic acid

0.003

0.007

Total Phosphorous

ISO 6878/2005

Sample treatment by oxidation with peroxodisulphate. After neutralization, determination is identical with P-PO4.

0.005

0.015

BOD5

SR EN 1899-1/2002

Dilution and seeding with allylthiourea.

Incubation at 200C for a defined period (5 days), in the dark. Determination of dissolved oxygen concentration before and after incubation

3.0

6.0

SR EN 1899-2/2002

Incubation at 200C for a defined period (5 days), in the dark. Determination of dissolved oxygen concentration before and after incubation.

0.5

1.8

COD-Cr

ISO 15705/2002

Digestion with sulphuric acid and potassium dichromate in the presence of silver sulphate and mercury (II) sulphate. The amount of dichromate used in the oxidation of the sample is determined by measuring the absorbance of Chromium (III) formed at the wavelength of 600 nm 20 nm for a range up to 1000 mg.L-1.

3.0

10.0

4.3. Sampling and analysis

The national laboratories involved in the TNMN are fully responsible with sampling, preserving, storage and analysis of water samples. The sampling and the analyses methods used are ISO standards according to the required performance criteria. For the entire data set, results for dissolved nutrients refer to water samples filtered by 0.45m pore size membranes prior to analysis. In Table 2, for each parameter, analytical methods and selected performance criteria are given.

Regarding the sampling frequency, during 1996 1999, for each selected sampling section, the annual frequency was 12. Starting with 2000, for certain water quality parameters (for which loads calculation was launched) BOD5 and nutrients forms, the mandatory frequency is 24 per year.

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(Pristol / Novo SeloChiciu / Silistra)

Figure 18: The Danube Station map TNMN

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5. Statistical approach

This chapter briefly presents the way in which the data comparability is tested based on univariate statistical approach, consisting of the following means (Helsel and Hirsch, 2002):

Basic descriptive statistics (number of values, minimum, maximum, mean, median, confidence intervals for mean 95%, lower and upper quartiles percentiles of 25 and 75 respectively, percentiles of 10 and 90 respectively, range and standard deviation).

T-test for independent variables (data set reported by the BG partner versus data set reported by the RO partner): the t-test is perhaps the most widely used method for comparing two independent groups of data. It is familiar to most water resources scientists. However, there are five often overlooked problems with the t-test that make it less applicable for general use than the nonparametric rank sum test. These are 1) lack of power when applied to non-normal data, 2) dependence on an additive model, 3) lack of applicability for censored data (data below the limit of determination, either LOD or LOQ), 4) assumption that the mean is a good measure of central tendency for skewed data, and 5) difficulty in detecting non-normality and inequality of variance for the small sample sizes common to water resources data.

Assumptions of the Test: The t-test assumes that both groups of data are normally distributed around their respective means, and that they have the same variance. The two groups therefore are assumed to have identical distributions which differ only in their central location (mean). Therefore the t-test is a test for differences in central location only, and assumes that there is an additive difference between the two means, if any difference exists. These are strong assumptions rarely satisfied with water resources data. The null hypothesis is stated as H0: x = y the means for groups x and y are identical.

Graphical comparison by box-plots: a very useful and concise graphical display for summarizing the distribution of a data set is the boxplot (Figure 10). Boxplots provide visual summaries of:

the center of the data (the median - the center line of the box)

the variation or spread (interquartile range - the box height)

the skewness (quartile skew - the relative size of box halves)

presence or absence of unusual values ("outside" and "far outside" values).

Boxplots are even more useful in comparing these attributes among several data sets, being valuable guides in determining whether central values, spread, and symmetry differ among groups of data.

Figure 19: Model of a box-plot representation

6. Results and discussion6.1. Primary monitoring datasets

The size of the dataset differs among the monitoring sites and the data source (BG and RO), depending on the number of sampling campaign. In the figures below, the number of annually results during 1996 2005 produced by Bulgarian and Romanian laboratories respectively, for each considered water quality parameter, is represented as it follows:

For sampling stations Pristol / Novo Selo transboundary section, in Figure 20 - Figure 22;

For sampling stations Chiciu / Silistra transboundary section, in Figure 23 - Figure 25.

As it can be clearly seen, starting from 2000 the number of results produced by RO increased (generally a double number) due to the launching by the ICPDR of the Load Assessment Programme designed in order to estimate the selected pollutants loads carried by the Danube River into the Black Sea, in which the considered sampling sections are included.

Figure 20: Number of annually results produced by BG and RO at Pristol / Novo Selo transboundary section for N-ammonium and N-nitrates during 1996 - 2005

Figure 21: Number of annually results produced by BG and RO at Pristol / Novo Selo transboundary section for P-orthophosphates and Total Phosphorous during 1996 - 2005

Figure 22: Number of annually results produced by BG and RO at Pristol / Novo Selo transboundary section for Biochemical and Chemical Oxygen Demand during 1996 2005

Figure 23: Number of annually results produced by BG and RO at Chiciu / Silistra transboundary section for N-ammonium and N-nitrates during 1996 2005

Figure 24: Number of annually results produced by RO at Chiciu / Silistra transboundary section for P-orthophosphates and Total Phosphorous during 1996 2005

Figure 25: Number of annually results produced by BG and RO at Chiciu / Silistra transboundary section for Biochemical and Chemical Oxygen Demand during 1998 2005

6.2. Data comparability based on univariate statistics long term data6.2.1. Comparison of monitoring data based on the entire data sets6.2.1.1. Pristol / Novo Selo transboundary section

a) Descriptive statistics: in Table 6 descriptive statistics for Pristol / Novo Selo transboundary sampling section are presented, based on the compilation of the two whole datasets provided by the involved partners (RO-BG) during 1996 2005. From the general view of the data set, the following observations could be done:

i. the number of values is generally higher for RO, due to the increased frequency s