§ Mr. DarlingTo ask the Secretary of State for Scotland what recent advice he has received on acceptable levels of lead in drinking water.
§ Mr. Michael ForsythCurrent medical advice is that there is little evidence to suggest that there are any health risks if the lead content in water is below the current European Commission maximum of 50 microgrammes per litre.
§ Mr. DarlingTo ask the Secretary of State for Scotland what is the most recent information available on levels of lead in drinking water in(a) Edinburgh and (b) Scotland; and what estimate he has as to when the levels will be reduced to within European Economic Community safety limits.
§ Lord James Douglas-HamiltonA recent survey of lead-plumbed properties in Edinburgh showed that the average lead level in tap water was less than 0–03 microgrammes per litre; it is estimated that not more than 15,000 people receive water which, on occasions, may exceed the maximum admissible concentration in the EC drinking water directive. Similar survey information is not available for the rest of Scotland. Six water authorities are completing programmes of treatment to reduce plumbosolvency and ensure compliance with the directive, as shown in the table: 395W
Number of supplies not meeting standard Estimated population affected ('000s) Region Now At end of 1989 Now At end of 1989 Dumfries and Galloway 22 None 65.0 None Highland 9 None 7.5 None Tayside 10 None 18.6 None Grampian 14 None 31.2 None Lothian 1 1 15.0 15.0 Strathclyde 22 16 73.0 37.0 TOTAL 78 17 210.3 52.0 Complete compliance should be achieved by Lothian early in 1991 while in Strathclyde all but two schemes will be completed by that date. The last two should be finished by 1992.
§ Mr. DarlingTo ask the Secretary of State for Scotland what action is being taken to implement the European Economic Community directive on safe levels of lead in water; and if he will make a statement.
§ Lord James Douglas-HamiltonResponsibility for the quality of water supplies lies with the water authorities, the regional and islands councils. They are introducing improved treatment to reduce plumbosolvency and are removing lead communication pipes in their ownership whenever there is an opportunity to do so. Enhanced capital allocations have been made available to local authorities to enable them to make faster progress with this work. Consumers are encouraged to replace that part of their lead piping leading to the kitchen tap by the availability of home improvement grant at an enhanced level for this purpose. These measures should ensure that the directive's limits are met.
§ Mr. DarlingTo ask the Secretary of State for Scotland what information he has on the effectiveness of lime and orthophosphate in reducing levels of lead in pipes and in tanks.
§ Lord James Douglas-HamiltonThe addition of both lime and orthophosphate to water which contains no significant amount of lead is aimed at reducing the plumbosolvency of the water; that is the ability to take up lead from lead plumbing, mainly in the ownership of consumers. Lime is generally effective, but some larger supply areas require further treatment using orthophosphate. Neither of these treatments affect the amount of lead available from lead pipes and tanks, they merely limit uptake.
§ Mr. DarlingTo ask the Secretary of State for Scotland what information he has on the level of nitrate pollution in drinking water in(a) Edinburgh and (b) Scotland.
§ Lord James Douglas-HamiltonPublic water supplies in Edinburgh are well within the nitrate limits set in the EC drinking water directive. Elsewhere in Scotland, no consumers receive from public supplies water with levels of nitrate above those in the directive. Local environmental health authorities will advise consumers on levels in private supplies and on any appropriate remedial action.
§ Mr. DarlingTo ask the Secretary of State for Scotland what information he has on levels of aluminium in drinking water in Scotland.
§ Lord James Douglas-HamiltonFourteen public supplies in Scotland contain levels of aluminium from396W natural sources above the maximum admissible concentration (MAC) set in the EC drinking water directive. In each case the levels are well within those recommended by medical advisers as being acceptable and derogations have been granted as provided in article 9 of the directive. More than 69 supplies do not comply because of the presence of aluminium used in treatment. Most of these supplies are already the subject of improvement programmes in terms of article 20 of the directive. Some which exceed the MAC occasionally have yet to be fully assessed following recent reinterpretation of the status of the MAC.
§ Mr. DarlingTo ask the Secretary of State for Scotland what information he has on levels of trihalomethane in drinking water in Scotland.
§ Lord James Douglas-HamiltonDetailed information on levels of trihalomethanes in drinking water is not held centrally. A national standard of 200 microgrammes per litre as an average over three months was set for Scotland in 1985 and all supplies comply with this limit. Consideration is currently being given to lowering the standard to 100 microgrammes per litre and to taking action to achieve this lower level in all supplies within a set period.
§ Mr. DarlingTo ask the Secretary of State for Scotland what information he has on the extent to which drinking water in Scotland is deliberately dosed with aluminium compounds; and for what purpose.
§ Lord James Douglas-HamiltonAlmost half of the water put into supply is treated in works where aluminium compounds are used to remove colour and suspended solids.