6.—(1) Subject to sub-paragraph (2), the slurry storage tank must have adequate storage capacity for the likely quantities of slurry produced from time to time on the premises in question, taking into account—
(a)the proposed method of utilising the slurry, and the likely rates and times of utilisation; and
(b)the matters mentioned in sub-paragraph (3).
(2) If it is proposed to utilise the slurry on the premises by spreading it on the land, the tank need not have a greater storage capacity than is adequate, taking into account the matters mentioned in sub-paragraph (3), to hold the maximum quantity of slurry likely to be produced in any four month period.
(3) The matters to be taken into account for sub-paragraphs (1) and (2) are—
(a)the storage capacity of any other slurry storage tank on the premises;
(b)the likely quantities of rainfall (including snow, hail or sleet) that may fall or drain into the slurry storage tank during the likely maximum storage period; and
(c)the need to provide at least 750 millimetres of freeboard in the case of a tank with walls made of earth and 300 millimetres of freeboard in all other cases.