These Regulations supplement Chapter III (Water Supply) of the Water Industry Act 1991 and primarily are concerned with the quality of water supplied by water undertakers whose areas are wholly or mainly in Wales (and water supply licensees using the supply systems of such undertakers) for drinking, washing, cooking and food preparation, and for food production, and with arrangements for the publication of information about water quality. The Regulations implement Council Directive 98/83/EC, on the quality of water intended for human consumption and their purpose is to protect human health from the adverse effects of any contamination of water intended for human consumption by ensuring that it is wholesome and clean. They also transpose the requirements of Council Directive 2013/51/Euratom laying down requirements for the protection of the health of the general public with regard to radioactive substances in water intended for human consumption.
The Regulations requires water undertakers to identify annually the areas ( water supply zones ) that are to be relevant for a particular year for the purposes of the application of provisions of the Regulations. They also prescribe standards of wholesomeness in respect of water that is supplied for human consumption by water undertakers, impose requirements relating to the disinfection of water and impose additional requirements for the treatment of surface water, provide for the monitoring of water supplies and require water undertakers and supplementary licensees to identify every point from which they abstract water for supply, to take samples from those points and to investigate failures to supply wholesome water.