HC Deb 10 July 1981 vol 8 c251W
Mr. Onslow

asked the Secretary of State for Transport whether he is satisfied that his Department, and the other authorities responsible for road construction works in the United Kingdom, are adequately informed about the water pollution dangers that may result from the use of blast furnace slag as fill material, where this causes leaching of sulphide into the water table.

Mr. Kenneth Clarke

My Department is well aware of the dangers to fish from sulphide pollution arising from the use of blast furnace slag in road works. I am advised that there is no danger to the public through leaching of sulphide into the water table. I have no reason to suppose that other highway authorities are not adequately informed of the pollution hazards.