§ 65 and 68. Mr. Bagier
asked the Minister of Transport (1) if he will take steps to ensure that specifications for new roadworks will require underfill to be obtained from pit heaps wherever possible; and whether he will consult with the National Coal Board about supply and costs;
(2) what steps he is taking to ensure that underfill for new motorways and roadworks is provided from pit heaps; and if he will make a statement.278W
Mr. Bob Brown
Specifications for works on roads, for which my right hon. Friend is the highway authority, permit the use of colliery shale as filling material. The only shales which have been excluded are those which are physically or chemically unstable.
Following consultation with the National Coal Board on supply, costs and chemical stability a Technical Memorandum was issued in September, 1968. This explained the conditions under which unburnt shales are acceptable and gave encouragement to the use of colliery shales for common filling. The degree of use of shale is dependent on its price, compared with the available alternatives and the choice of acceptable filling material rests with the contractor.