2. Difficulties encountered

2.1 Distributed water quality, public health and consumer demand

• Surface water resources are rarely of excellent quality, and groundwater is increasingly contaminated by man-made pollutants and their metabolites. The major difficulty is therefore to always supply good quality water, in compliance with current regulations, even when the quality of the resource is (or is likely to be) contaminated.

  In addition, the maximum values imposed (limits and references) for each regulatory drinking water quality parameter