HARMONIZED PT SYSTEMS IN THE GERMAN WATER SECTOR

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1 The First International Proficiency Testing Conference Sinaia, România 11 th 13 th October, 2007 HARMONIZED PT SYSTEMS IN THE GERMAN WATER SECTOR Michael Koch 1, Ulrich Borchers 2 and Frank Baumeister 1 1 Institute for Sanitary Engineering, Water Quality and Solid Waste Management, University Stuttgart, Bandtäle 2, Stuttgart, Germany, 2 IWW Water Centre, Moritzstraße 26, Mülheim/Ruhr, Germany 1 Michael.Koch@iswa.uni-stuttgart.de and Frank.Baumeister@iswa.unistuttgart.de, 2 u.borchers@iww-online.de Abstract Based on a national guideline and a German standard, the PT systems in the legally regulated sector of water analysis were harmonized in the last years. The PT providers cooperate for the benefit of the participants and the system in total. The two different ways of cooperation in the environmental (waste and ground water) and drinking water sector are described. The essential part of the German standard will soon be published as an ISO technical report. Thus, the German harmonized systems could serve as a model for international harmonization of PT schemes. Key words Proficiency testing, water analysis, harmonization, drinking water, waste water, ground water 1 INTRODUCTION In many different sectors proficiency tests (PT) are organized by various PT providers, all having their own evaluation and assessment system. Even when several providers claim to assess the results on the basis of the same directive (e.g., the EU drinking water directive [1]), the results of the assessment can differ considerably among the providers, as has been shown by the COEPT project [2]. A few years ago, the German situation in the legally regulated sector of analysis of waste water and drinking water was also very difficult. There were 16 different regulations in Germany, which was due to the federal constitution of Germany and the responsibilities for environmental as well as for drinking water issues being with the state authorities. Therefore, laboratories analyzing water in different federal states 17

2 in Germany had to fulfil different requirements in the different federal states, and sometimes had to take part in similar proficiency tests in the various states. The recognition of other PT participations was often not possible, because the procedures of the PT providers were different in the various states. To overcome this unacceptable situation, a guideline [3] and a national standard [4] were developed. Based on these documents, the PT providers started to cooperate on the basis of a self commitment. The resulting systems are different for drinking water and waste water. They are described in the following, and may probably serve as an example for other similar cooperations in Europe. 2 NATIONAL GUIDELINE AND STANDARD The above mentioned guideline [3] was developed in 2000 in the LAWA (German Working Group on water issues of the Federal States and the Federal Government) for use in the legally regulated area of water analyses in the environment, i.e. ground and waste water. It deals with the special needs of organisation and execution of PTs in this field as well as with the evaluation and assessment of the data. In order to achieve a higher degree of harmonization, only one suitable method for evaluation and assessment was selected from the wide variety of approaches described in the International Harmonized Protocol [5], [6]. Together with other guidelines, this was the basis for the development of a German standard [4], which goes into more details especially as regards the quality management of the PT providers. This was done, because at that time no standard describing these requirements was available. Currently, such a standard (ISO 17043) is under development as a revision of the ISO guide 43. A very important point in the German standard is the application of a special robust statistical method and the use of a variance function, to reduce the inequalities in the assessment of the laboratories due to unexpected variations of the standard deviation among different concentration levels. Unfortunately, there was no liaison with the ISO committee that produced the ISO [7], so that these methods could not yet be integrated in the new ISO standard. But as the German standard uses a method that has a sound statistical basis, it is in full accordance with ISO An extract of the German standard, describing the statistical evaluation and an assessment method, recommended for water PTs, will be published in due course of time as an ISO Technical Specification. 3 HARMONIZATION IN THE ENVIRONMENTAL SECTOR Using the German national guidelines, the 11 PT providers in the environmental sector agreed to cooperate in the following way: There is a programme of PT rounds defined by the needs of the environmental authorities and regulations in Germany. Identical PT rounds are organized by several PT providers (normally 2 to 4) at the same date, covering whole Germany. The PT rounds are announced by all federal state authorities or by the PT provider in charge. The laboratories wishing to participate can register at any of these organizations and are entered into a central database. The registered participants are then allocated to the different PT providers 18

3 according to capacities available at the different PT providers. One of the PT providers is responsible for the coordination. Details of the PT round such as preparation of samples, stability checks, selection of bottles and spiking substances or conservation during transport are discussed in a meeting of the PT provider working group. Evaluation and assessment of the PT round is done by all PT providers in exactly the same way, following the national guideline and standard. After finishing the evaluation and assessment the results are reported to the participants and to the respective federal authority responsible for the state where the laboratory resides. 4 HARMONIZATION IN THE DRINKING WATER SECTOR Compared to the formation of one PT system with different providers in the environmental sector the PT providers in the drinking water sector work together in a less strong, but nevertheless successful cooperation. In Germany there are 3 PT providers in this field, who had been working completely independent until Since 2004 they have harmonised their PT programme and their way of evaluation and assessment. In 2003 the German drinking water regulation was changed [8], to implement the EU council directive 98/83/EC on the quality of water intended for human consumption [2]. In this new regulation requirements on the quality control of laboratories are defined. In a working group of all PT providers together with the German Federal Environmental Agency (UBA) a recommendation for PT participation of drinking water laboratories [9] was developed. This recommendation includes requirements for PT providers as well as those for laboratories. In particular, it requires the laboratories to participate regularly and successfully (at least once in 2 to 3 years) in one PT round for each parameter they are accredited for. The 3 PT providers decided to create 2 independent PT systems that work in a fully harmonized way. The programmes of the two systems, integrating all relevant drinking water parameters in 10 different rounds, are identical, but with a shift of 1 year. So, if a participant is failing in one of the parameters, the laboratory can participate for this parameter in the other system in the following year. Table 1 shows the ten different PT rounds and table 2 explains the programme of the two providers. This system is accompanied by another PT system, mainly for microbiological and some basic chemical parameters. The PT providers have an annual meeting to optimize the system and to arrange necessary changes. Additionally, there are annual meetings with all participants of the PT schemes. These meetings are focused in the exchange of knowledge and on training aspects, if any problems or misunderstandings occur. 19

4 Table 1 Drinking Water PT rounds in Germany A1 Anions: bromate, fluoride, nitrate, nitrite, chloride, sulfate, phosphorous, cyanide, turbidity Trace elements: chromium, copper, lead, cadmium, nickel, chromium(vi), silicate A3 Cations, part 1: aluminium, iron, manganese, sodium, potassium, colour (436 nm) Other inorganic parameters: conductivity, oxidisability, TOC, selenium, antimony, arsenic A5 Cations, part 2: boron, calcium, magnesium, mercury, ammonium, ph-value O1 Pesticides 1: N- and P-pesticides (triazines, phenylureaherbicides) Halogenated VOC/Benzene: 1,2-dichloroethane, tetrachloroethene, trichloroethene, trichloromethane, bromodichloromethane, dibromochloromethane, tribromomethane, benzene O3 PAH: benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(ghi)perylene, indeno(1,2,3-cd)pyrene Pesticides 2: phenoxyalkanecarbonic acids O5 Special organic parameters: e.g. glyphosate/ampa, dalapone/tca, chloropesticides, epichlorohydrine or others Table 2 Programme of the two PT schemes lögd / IWW A3 O3 A5 O5 A1 O1 AQS-BW / BSG A5 O5 A1 O1 A3 O3 5 CONCLUSIONS In Germany the PT providers decided for cooperation instead of competition. The resulting systems are different for the environmental and the drinking water sector. Both systems have been working very well for several years. It is especially to the benefit of the participating laboratories, but also for the authorities and the PT providers. The resulting PT systems cover all the necessary parameters in the water sector. The starting point for the harmonization was the development of a national standard specific for the water sector [4] and some recommendations from the federal and state authorities. Those parts of this standard that are describing the recommended 20

5 evaluation that fits best the needs in the water sector, will be described in an ISO technical report in the near future. This could be the basis of a harmonized European System or it could at least serve as a good source of ideas for a European network of PT providers. Similar as in the drinking water sector, the requirements for water analyses within the Water Framework Directive [10] are the same across the whole European Union. Therefore, harmonized PT systems would be most welcome or necessary for some areas. The German system could serve as model. The German PT providers are prepared to share their knowledge and to extend this system to Europe and also to other PT providers or, if necessary, also to provide service to accreditation bodies and authorities outside Germany. REFERENCES [1] EU COUNCIL DIRECTIVE 98/83/EC of 3 November 1998 on the quality of water intended for human consumption. [2] Boley, N., van der Veen, A.M.H., Robouch, P., Golze, M., van de Kreeke, J., Örnemark, U., Tylee, B.: Comparability of PT schemes what did we learn from COEPT? Accred Qual Assur 11: (2006). [3] Länderarbeitsgemeinschaft Wasser (LAWA): Merkblatt A-3:2001 Ringversuche zur externen Qualitätsprüfung von Laboratorien. In: LAWA (ed.): AQS-Merkblätter zur Wasser-, Abwasser- und Schlammuntersuchung. Erich Schmidt Verlag Berlin. [4] DIN :2003 Ringversuche zur externen Qualitätskontrolle von Laboratorien. [5] Thompson; M., Wood, R.: International Harmonized Protocol for Proficiency Testing of (Chemical) Analytical Laboratories. J. AOAC Int. 76, (1993). [6] Thompson; M., Ellison, S.L.R., Wood, R.: The International Harmonized Protocol for the Proficiency Testing of Analytical Chemistry Laboratories. Pure Appl. Chem. 78, (2006). [7] ISO 13528:2005 Statistical methods for use in proficiency testing by interlaboratory comparisons. [8] Verordnung über die Qualität von Wasser für den menschlichen Gebrauch (Trinkwasserverordnung TrinkwV 2001) BGBl. I, S [9] Umweltbundesamt: Empfehlung für die Durchführung von Ringversuchen zur Messung chemischer Parameter und Indikatorparameter zur externen Qualitätskontrolle von Trinkwasseruntersuchungsstellen. Bundesgesundheitsbl - Gesundheitsforsch - Gesundheitsschutz 46, (2003). [10] EU Directive 2000/60/EC of the European Parliament and of the Council establishing a framework for the Community action in the field of water policy. 21