European standards for drinking water

Previously, two sets of international standards were used WHO European Standards for Drinking Water (last revised in 1970) and WHO International Standards for Drinking Water (last revised in 1971). Revision of these began in December 1978 and was completed in 1982. The revision formed a part of the International Drinking Water and Sanitation Decade, which has the aim of providing a supply of safe drinking water for all by the year 1990. 

WHO. 1970. World Health Organization. European standards for drinking water, 2nd ed. Geneva WHO, 33. 

Clean and wholesome drinking water is of essential importance for any society. Therefore, water intended for human consumption is one of the most comprehensively regulated and monitored media in any country. In this section, an overview is given on the standards for drinking water quality which are laid down by the European Community (EC), by the US Federal Government and by the Word Health Organization (WHO). 

The Jurassic carbonated aquifers of the Gijon Fonuation (IGME, 1984) can be regarded as one of the main aquifers of the Asturian region. Nevertheless, in some areas, the groundwater from these aquifers are not suitable for urban water supply because the concentration of the dissolved sulphate exceeds the European Union water quality standard for drinking water (250 mg/1). 

This slide shows an example taken from an European standard for the analysis of mercury in water. For drinking water the standard states a reproducibility variation coefficient of 30% on a mercury concentration level of 0.8 pg/l. Provided that we can prove that we can perform as described in the standard our expanded measurement uncertainty (95% confidence) is estimated to 60%. 

With few exceptions, drinking water standards for organic substances did not exist until recently. The WHO European and International Drinking Water Standards (1970 and 1971) included pesticides and polycyclic aromatic hydrocarbons (PAHs), and total extractable organics were included in the European edition. 

In the European Union, because of the general view that there should be no pesticides in drinking water, a precautionary principle is applied, and standards are set as low as is reasonably achievable. EEC directive 98/83/CE for drinking water therefore set limit values at 0.1 /rg/1 for each individual pesticide and 0.5 /rg/1 for total pesticides. For surface water used to produce drinking water, these values are 2 /rg/1 for each individual substance and 5 /rg/1 for total pesticides. 

A European Standard is in preparation [12.34], which specifies the qualities of limestones used for drinking water treatment. Table 12.5 shows how the current proposals classify calcium carbonates into ... 

They must be based on well defined standardized analytical techniques (and when necessary on the determination of specific components). They must be coordinated with the standards and limits proposed for other ways of exposure as for instance, the European Standards of EEC for drinking water "It is recommended that six compounds (fluoranthene 3,4 benzfluoranthene 11,12 benzfluoran-thene 11,12 benzperylene 3,4 benzopyrene, indeno (1,2,3-cd) pyrene) will be analysed and their concentrations should not exceed 0,2 ]Jg/l". 

With further new European standards for lead in mind (25 pg/1 from December 2003, 10 pg/1 from December 2013), the Drinking Water Inspectorate (DWI) issued Information Letters (DWI, 2000, 2001) that required the water companies in England and Wales to optimise treatment measures to reduce plumbosolvency, including the dosing of orthophosphate. Optimisation of plumbosolvency control treatment in England and Wales was required if >5% of at least 100 random daytime (RDT) samples had exceeded 10 pg/1 in the water supply zone(s) supplied by a treatment works and in consequence 95% of public water supplies are now dosed with orthophosphate for plumbosolvency control. 

Water for injection (WFI) is the most widely used solvent for parenteral preparations. The USP requirements for WFI and purified water have been recently updated to replace the traditional wet and colorimetric analytical methods with the more modern and cost-effective methods of conductivity and total organic carbon. Water for injection must be prepared and stored in a manner to ensure purity and freedom from pyrogens. The most common means of obtaining WFI is by the distillation of deionized water. This is the only method of preparation permitted by the European Pharmacopoeia (EP). In contrast, the USP and the Japanese Pharmacopeias also permit reverse osmosis to be used. The USP has also recently broadened its definition of source water to include not only the U.S. Environmental Protection Agency National Primary Drinking Water Standards, but also comparable regulations of the European Union or Japan. 

Water samples (drinking water, rain, sea, river or waste water and others) have been characterized by ICP-MS with multi-element capability in respect to metal impurities (such as Ag, Al, As, Ba, Be, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Na, Sb, Se, Mg, Mn, Mo, Ni, Pb, Tl, Th, U, V and Zn) in many laboratories in routine mode with detection limits at the low ng I 1 range using ICP-QMS, and below by means of ICP-SFMS. Drinking water samples are controlled in respect of the European legislation (Council Directive 98/83/EC of 3 November 1998 on the quality of water intended for human consumption). For quality control of analytical data, certified standard reference materials e.g. drinking water standard (40CFR 141.51), river water reference material SLRS-4 or CASS-2 certified reference sea-water material and others are employed. 

In the case of Cd in drinking water the performance criteria are clearly speci-bed as 10 percent for both trueness and precision. Therefore, it is rather surprising to see PT providers stating assigned standard deviations of 5, 7, 10, or even 14 percent for Cd in water, in compliance with the WFD. This is because some PT providers only consider trueness, others, in turn, combine trueness and precision. Some consider precision properly, others take it as a direct estimate of the normalization factor. To improve such situations, the European Union initiated the CoEPT project to study the differences and similarities in the operation of PT schemes and the evaluation of PT results in view of implementing a harmonized approach to provide a basis for the comparability of the PT schemes operated on the market [70]. 

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