To ask the Secretary of State for the Environment what level of benzene contamination is acceptable in drinking water; and what are the standards required in Britain, the rest of the European Economic Community and the United States of America, respectively.

The Water Supply (Water Quality) Regulations 1989, which incorporate the requirements of the EC drinking water directive, set a standard of 10 microgrammes per litre for dissolved or emulsified hydrocarbons, which includes benzene; however, the regulations do not contain a specific standard for benzene. The World Health Organisations guideline value for benzene in drinking water is 10 microgrammes per litre and the United States maximum contaminant level is 5 microgrammes per litre.