HC Deb 30 January 1987 vol 109 cc464-5W
Mr. Chris Smith

asked the Minister of Agriculture, Fisheries and Food what concentration of mercury, cadmium and zinc he regards as trace, with regard to sewage sludge disposed of at sea by the United Kingdom.

Mr. Gummer

In the absence of specific limits for trace contaminants in the relevant international conventions, my Ministry aims to keep permissible concentrations in sewage sludge below 10 parts per million in the case of mercury and 20 parts per million in the case of cadmium. Disposal of zinc other than as a trace contaminant is not prohibited by the conventions.