2. A hazardous substance shall only be present at ambient temperature in a buried or mounded vessel in a vessel area if—
(a)it was present at ambient temperature in a buried or mounded vessel in that vessel area at any time during the establishment period;
(b)the buried or mounded vessel in which it is present does not have a greater capacity than that specified in column 3 of Table C; and
(c)the pressure at which it is present in the buried or mounded vessel does not exceed—
(i)atmospheric pressure, if the substance was not present at above atmospheric pressure at ambient temperature in a buried or mounded vessel in that vessel area at any time during the establishment period; or
(ii)the pressure specified in column 4 of Table C, in any other case.