§ Mr. Kilroy-Silkasked the Secretary of State for the Environment (1) what progress water authorities are making in reducing nitrate levels to comply with the EEC directive of a 50 mg per litre maximum;
(2) which water authorities currently have nitrate in drinking water in excess of 50 mg per litre;
(3) what surface waters have concentrations of nitrate in excess of 50 mg per litre; and by how much they have increased in recent years.
§ Mr. MacfarlaneIn 1984, some water supplies in Anglian, Severn-Trent, Yorkshire and Thames water authority areas exceeded 50 mg per litre NO3 for some part of the year. In these areas steps have been or are being taken to reduce nitrate concentrations in drinking water. All the authorities will need to comply with the EC directive figure of 50 mg per litre or with the terms of any derogation I may issue later this year.
My Department's harmonised monitoring scheme, using data collected by water authorities, provides a comprehensive picture of the nitrate situation in the main rivers in England, Scotland and Wales. In 1983, of over 200 monitoring stations, only five recorded average nitrate concentrations slightly above 50 mg per litre.
These stations are situated on the Rivers Lee, Blackwater, Idle, Stour (Suffolk) and Stour (Hereford and Worcester).
Until 1980 nitrate concentrations had been increasing on average by 0.7 mg per litre annually in some 25 rivers. More recent information is now being assessed by the nitrate co-ordination group.