§ Mr. Cohenasked the Secretary of State for the Environment what information he has about the incidence of new synthetic substances being discharged into Britain's rivers, estuaries and coastal waters; and what is his policy towards taking decisions on whether such xenobiotic substances should be discharged on the basis of technically available reduction options.
§ Mr. WaldegraveNew synthetic substances can only be placed on the market following notification to the Government and presentation of environmental information to enable an assessment to be made of their potential hazards, including those to the aquatic environment.
There exists limited information on discharges of synthetic substances to waters either from manufacture or from use, or from point and diffuse sources. Decisions on the control of discharges are taken on the basis of the quality objective approach and may require substitution or control of use as well as discharge controls.
§ Mr. Cohenasked the Secretary of State for the Environment if his Department has any plans to revise and update the estimated loads of contaminants carried by British rivers into the North sea quoted in the final report prepared for his Department by the Institute of Offshore Engineering (May 1984) entitled "Input of Contaminants to the North Sea from the United Kingdom"; what assessment has been made of the reliability of the 1984 calculation techniques and of the river monitoring programme on the basis of which the load estimates were made.
§ Mr. WaldegraveThe loads of contaminants entering the North sea via rivers and by direct discharge have been re-estimated as part of the preparations for the forthcoming North sea conference. This re-assessment has been based on a better method of calculation and on more sensitive analyses.
§ Mr. Chris Smithasked the Secretary of State for the Environment what guidance Her Majesty's Government issue to industry about measures to prevent pollution of sediments at source or prior to discharge.
§ Mr. WaldegraveThe Government do not issue advice to industry concerning measures to prevent the pollution of sediments by discharges. Discharge consents for aqueous effluent are set by water authorities and in setting these consents they consider the effects of the discharge on the aqueous environment—including sediments.
§ Mr. Chris Smithasked the Secretary of State for the Environment what studies Her Majesty's Government have conducted into the technical and economical feasibility of reducing hydrocarbon discharges into the freshwater, marine and estuarine eco-systems to 5 ng/L. from oil refineries operating within the United Kingdom.
§ Mr. WaldegraveThe Government have conducted no such studies. It is possible, but very expensive, to reduce the oil content of refinery discharges to 5mg/1, but there are no good environmental reasons to require such a standard in all cases. I am assuming that "5ng" in the hon. Member's question is a misprint for "5 mg". The difference is a factor of a million.