A pipe for conveying rain-water from a roof shall not be used for the purpose of conveying the soil or drainage from a sanitary convenience.
The soil pipe from a water-closet shall be properly ventilated.
A pipe for conveying surface water from premises shall not be permitted to act as a ventilating shaft to a drain or sewer conveying foul water.
If it appears to the local authority . . . that there is on any premises a contravention of any provision of this section, they may by notice require the owner or the occupier of those premises to execute such work as may be necessary to remedy the matter.
Sections 99 and 102 below apply in relation to a notice given under subsection (4) above.