'Waste' includes:

a. any substance which constitutes a scrap material or an effluent or other unwanted surplus substance arising from the application of any process; and

b.any substance or article which requires to be disposed of as being broken, worn out, contaminated or otherwise spoiled;

but does not include a substance which is an explosive within the meaning of the c.17. Explosives Act 1875.

Anything which is discarded or otherwise dealt with as if it were waste shall be presumed to be waste unless the contrary is proved.