§ Mr. MaxtonTo ask the Secretary of State for Scotland, pursuant to his answer to the hon. Member for Southwark and Bermondsey (Mr. Hughes) of 21 January,Official Report, columns 164–74, what is his estimate of the total population of the supply zones listed, where water quality does not fully comply with the requirements of the EC drinking water directive.
§ Lord James Douglas-HamiltonMy answer of 21 January 1992 to the hon. Member for Southwark and Bermondsey listed those zones currently subject to improvement undertakings given by water authorities because one or more of the standards set in the water quality regulations has been infringed at some time. The total population of the zones listed is about 2.5 million. Well over half that population receives water which has breached only one of the 57 standards and in many cases breaches were minor or occasional. Water authorities' annual reports for July to December 1990 showed that in that period many of the zones listed had no failures of the standards concerned.
The population of zones listed as not meeting the standard for iron is almost 0–5 million. In most of these cases the water put into supply fully meets the standard but old iron water mains may cause occasional failures at consumers' taps. Zones for which the undertaking relates only to the standard for trihalomethanes, a United Kingdom standard not set in the EC directive, account for a population of about another 0.;5 million.