3. The capacity of the effluent tank—
(a)in the case of a silo with a capacity of less than 1500 cubic metres, shall be not less than 20 litres for each cubic metre of silo capacity; and
(b)in the case of a silo with a capacity of 1500 cubic metres or more, shall be not less than 30 cubic metres plus 6.7 litres for each cubic metre of silo capacity in excess of 1500 cubic metres.