ORDINANCE No. 13 OF 1901.
Public Health.
25. Every main house-drain, wherever practicable, shall be ventilated at its upper end by an opening in free communication with the outer air. This opening shall be placed in such a position as to render any emanations from it as little obnoxious as possible.
Note—This is, in most cases, to be done by carrying up a well-jointed pipe, not less than four inches in clear internal diameter, to some point above the eaves of the building, which is not in close proximity to any window or chimney. In the case of rural or suburban tenements, the ventilating opening may be provided on any eminence, or open space at a distance from the dwelling, the ventilating pipe and opening, in this case, being not less than four inches in internal diameter.
26. Every main house-drain shall have a ventilating opening near to its lower end, and no trap or other obstruction to the free circulation of air shall exist between this opening and the one described in the preceding bye-law.
If there be a trap between the house-drain and the public sewer, then an opening shall be made on the house-side of the trap, and the said opening shall be so arranged as to give access to the trap for inspection, cleansing, or repair.
If there be no trap between the public sewer and the house-drain, no special opening need be provided at the lower end.
27. Drains leading from a single trap and not being more than sixty feet long, need not be provided with an elevated ventilating opening at their upper end; but, if this be omitted, they shall be provided with a trap, disconnecting them from the public sewer, and shall have a ventilating opening at the lower end on the house-side of the trap.
28. Ventilating and fall pipes of stoneware shall be securely fixed to the exterior surfaces of walls with wrought iron bands fitted round the pipe and made fast to the wall with two wrought iron spikes not less than four inches in length. Metal pipes shall also be fixed as above or shall have two ears fixed to them and secured to the wall with two wrought iron spikes, not less than four inches long.
29. Down-pipes, conveying rain-water from roofs, shall be constructed of cast or welded wrought-iron, and when the down-pipe discharges into the house-drain, it shall be completely disconnected therefrom, as described in No. 31 of these bye-laws, and fitted with a bend, shoe, or pedestal pipe. Wherever practicable, the rain-water down-pipes on the street side of buildings shall be carried under the footpath and discharge into the side-channel.
Note. It is most important that such pipes should be completely disconnected from the sewers so that they cannot by any possibility serve as conduits for conveying sewer air into the dwelling.
30. Waste-pipes from baths, sinks, and other similar appliances on the upper floors of buildings shall be of cast-iron socketed pipes or wrought-iron welded-pipes with screwed joints coated with bituminous composition, or, in the case of wrought-iron, galvanised; or of well-glazed stoneware socketed pipes, or other approved materials, securely fixed outside the wall, and provided, at each point of connection, with a suitable head, and at their lower extremity with a bend, shoe, or pedestal pipe. All joints of stoneware pipes to be made in the manner provided by No. 5 of these bye-laws.
Note—Zinc, tin-plate, riveted, or lap-jointed sheet-iron will not be approved.
31. Waste-pipes, as well as down-pipes from roofs, shall not be connected direct with any drain but shall discharge in the open air near to or over a trap, and they shall be brought down to within one foot or less from the ground.
ORDINANCE No. 13 OF 1901.
Public Health.
32. No rain-water pipe from the roof of a building shall be used as a ventilating shaft to any drain which communicates or is designed to communicate with a public sewer.
Note—Rain-water pipes terminate at the eaves of the house, a point not high enough above windows to be a sure ventilating outlet.
33. Any person who may have laid any drain or constructed drainage works connected therewith shall not cover up such drain or works until the same shall have been previously inspected and passed by the Board, and such person shall give three clear days' written notice to the Board that such drain or works are ready for inspection, and such notice shall be delivered at the Office of the Board in a form of which printed blank copies may be obtained gratis in English and Chinese on application at the Office of the Board, or, in the case of villages, at any village Police Station between the hours of 10 a.m. and 4 p.m.
34. Before any drain is covered in, it shall be inspected and tested to ascertain whether it is water and air-tight; and no drain that fails in this respect shall be passed. After inspection, the earth shall be carefully filled in, above and around the drain, and thoroughly rammed and consolidated. For a depth of at least six inches, above the invert of the sockets of the pipe, selected material, free from stones larger than will pass through a 2-inch ring, shall be used in filling in the trench.
35. The floors of cook-houses, stables, cow-sheds, and the like, where practicable, shall be elevated above the ground outside the dwelling, and be provided with surface channels, passing out through the wall, and delivering above a trapped-gulley, outside. When new drains are being laid and where the floor is at the level of the ground outside, the surface-channel of the cook-house shall be connected to a trap, outside the house, by a straight open pipe, terminating above the water-level of the trap, which shall be accessible and in free communication with the air.
36. The floors of cook-houses, latrines, privies, and back-yards shall be paved with some impervious and durable material, such as granite sets, or vitrified bricks, laid on a bed of good concrete not less than four inches thick, and pointed with good mortar, or with good concrete laid in a bed not less than six inches thick and rendered with cement, and shall have a fall from the walls to the outlet of at least one inch to the foot.
37. All surfaces of back-yards and paved areas of premises, wherever practicable, shall have a fall from the walls of the building towards the trap or inlet of the drain, at the rate of not less than one inch to the foot, and such inlet shall be placed as far from the walls as practicable.
38. Open surfaces, such as back-yards, court-yards, or other spaces, on which slops are thrown, or from which foul waters flow, shall be provided with trapped connections to the house-drains, for the removal of such waters as well as some of the rain-water. But such surfaces shall be properly paved, in the manner prescribed for back-yards and cook-houses, so that no sand or silt may be washed into the drains from them.
39. Wherever an outlet is available, surface channels shall be provided to carry excessive rain-fall from premises, and these channels shall be properly connected with the storm-water channel in the street. Traps not less than 4 inches in diameter in connection with the house-drain shall be placed in this surface channel, which will carry off slops or sewage, as well as some rain-fall.
40. Rain-water shall be diverted from house-drains by means of surface channels or otherwise to the fullest extent practicable.
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