HC Deb 31 March 1971 vol 814 c378W
109. Mr. Wingfield Digby

asked the Secretary of State for the Environment what estimate he has made of oil spillage into the waters surrounding Great Britain in 1969 and 1970, respectively; and what proportion of the oil came from collision, strandings and the cleaning of ships' tanks.

Mr. Peter Walker

It is impossible to give any precise estimate but the main source of oil pollution is thought to be discharges of tank washings and contaminated ballast water from ships. The Oil in Navigable Waters Bill will enable us to tackle this form of pollution more effectively.