(1) No person shall construct or use any conserving-tank without the written consent of the local authority.

(2) If the local authority consents to the construction of a conserving-tank, the tank shall conform to the requirements of the following subsections.

(3) Except as provided for in subsection (4), the net capacity A (calculated by using the depth as measured from the invert-level of the inlet-pipe to the floor of the tank) shall be not less than –

Q = d × c × q litres
Where—
d= the maximum number of days between complete evacuations of the tank;
c = the number of contributors to the tank;
q = in the case of residential and institutional buildings, 120 litres;
or
in the case of business and public buildings, 30 litres.

(4) A conserving-tank shall have a minimum capacity of 5 000 litres, but such capacity shall, in any case, be sufficient for at least five day’s storage.

(5) The suction lift in the suction-pipe shall not exceed 2,1 metres at an altitude of 2 000 metres above sea-level and 3 metres at sea-level. In localities between these altitudes the maximum permissible lift shall be determined by interpolation.

(6) The tank shall be so constructed that any gas forming in the tank can escape along the sewer through the vent-pipe at the top of the sewer to which such tank is connected.

(7) The tank shall be placed as near as possible to a street boundary, so that it can readily be emptied. If this is not possible, a convenient means of access to the tank shall be provided.

(8) The tank shall be provided with a manhole, constructed in accordance with the provisions of section 77, for inspection and cleaning of the tank.

Such manhole shall be brought up to above ground-level, so as to prevent spring-water, subsoil-water, surface-water or storm-water from entering the tank.

(9) The tank shall be watertight.

(10) The tank shall be designed so as to support 300millimetres of earth cover over the top of the covering slab. Where vehicular traffic might pass over the slab, the additional load imposed upon such slab due to the passage of such vehicular traffic shall be taken into account in the design of the tank.