§ Mr. Simon HughesTo ask the Secretary of State for Scotland if he will list those water sources which have yet to be chemically dosed to reduce absorption of lead into drinking water supplies; and if he will make a statement.
§ Lord James Douglas-Hamilton[holding answer 11 November 1991]:There are over 600 water treatment works in Scotland, of which about two-thirds do not have chemical dosing which could affect levels of lead in tap water. Not all supplies require such dosing and those currently without it are mainly small supplies or are from 490W borehole sources. Around 90 per cent. of the population are served by supplies which do not receive this form of treatment.
Only one scheme designed to meet the requirements of the EC Drinking Water Directive as regards lead remains to be completed next year; this is part of a major treatment works reconstruction. The Water Supply (Water Quality) (Scotland) Regulations 1990 set a stricter standard for lead than the directive and all water authorities are now assessing their water supply zones to identify any where this standard may be exceeded. These assessments will determine zones in which further treatment will be considered.