31. An occupier of a holding who stores any organic manure (other than slurry), or any bedding contaminated with any organic manure, must store it—
(a)in a vessel;
(b)in a covered building;
(c)on an impermeable surface; or
(d)in the case of solid manure that can be stacked in a free standing heap and that does not drain liquid from the material, on a temporary field site.