Potable water must not contain contaminants that could lead to acute or chronic adverse health effects or exhibit undesirable aesthetic aspects such as objectionable odour or taste. Such contaminants can arise from the materials used to distribute and store drinking water. The Construction Product Directive demands that such products satisfy 'Essential Requirements' including requirements for safety and health. The quality of drinking water in EU countries is covered by the Directive 80/778/EEC but this does not cover many of the contaminants that can be associated with the above mentioned products. Most EU countries therefore operate regulatory schemes for the approval of such products and materials. Attempts to harmonize the different schemes have so far met difficulties in that existing systems are heaviliy biased to 'organic' products. The approval of metallic and cement-based products is much more difficult because leaching from these products, unlike organic products, can be markedly influenced by the chemical nature of drinking water.
The aim of this pre-normative research project is to carry out investigations in the area of effects on water quality of materials in contact with drinking water that will lead to the development of screening tests for those inorganic materials for which there are no data available. In addition, a rig test to determine the influence of different water types will be developed.
The investigations on the different parameters related to the test procedures for metallic and cementitious materials are in good progress (mid-term situation). For cements, many data are now available and few complementary experiments are required for the design of a standardized test procedure. For metallic materials, much work still needs to be performed before an accurate test procedure can be designed.
The programme is separated in various work packages. A critical assessment of the tests currently available for metallic products and comparison of their performance and usefulness will involve the evaluation of (1) the impact of dissolved metallic elements on the organoleptic water characteristics, (2) the migration of metallic elements from coupons according to water characteristics and contact time (comparison of existing procedures), and (3) the design of test conditions to be applied to a wide range of alloys and water types. Investigations on preconditioning procedures for cementitious materials will also be carried out by testing materials as pipe sections filled with test water.